Sample records for geomorphology

  1. Geomorphological Fieldwork (United States)

    Thornbush, Mary J; Allen, Casey D; Fitzpatrick, Faith A.


    Geomorphological Fieldwork addresses a topic that always remains popular within the geosciences and environmental science. More specifically, the volume conveys a growing legacy of field-based learning for young geomorphologists that can be used as a student book for field-based university courses and postgraduate research requiring fieldwork or field schools. The editors have much experience of field-based learning within geomorphology and extend this to physical geography. The topics covered are relevant to basic geomorphology as well as applied approaches in environmental and cultural geomorphology. The book integrates a physical-human approach to geography, but focuses on physical geography and geomorphology from an integrated field-based geoscience perspective.

  2. Tectonic geomorphology

    National Research Council Canada - National Science Library

    Burbank, Douglas West; Anderson, Robert S


    Tectonic geomorphology is the study of the interplay between tectonic and surface processes that shape the landscape in regions of active deformation and at times scales ranging from days to millions of years...

  3. Forensic geomorphology (United States)

    Ruffell, Alastair; McKinley, Jennifer


    Geomorphology plays a critical role in two areas of geoforensics: searching the land for surface or buried objects and sampling scenes of crime and control locations as evidence. Associated geoscience disciplines have substantial bodies of work dedicated to their relevance in forensic investigations, yet geomorphology (specifically landforms, their mapping and evolution, soils and relationship to geology and biogeography) have not had similar public exposure. This is strange considering how fundamental to legal enquiries the location of a crime and its evolution are, as this article will demonstrate. This work aims to redress the balance by showing how geomorphology featured in one of the earliest works on forensic science methods, and has continued to play a role in the sociology, archaeology, criminalistics and geoforensics of crime. Traditional landscape interpretation from aerial photography is used to demonstrate how a geomorphological approach saved police time in the search for a clandestine grave. The application geomorphology has in military/humanitarian geography and environmental/engineering forensics is briefly discussed as these are also regularly reviewed in courts of law.

  4. Geomorphology of Minnesota (United States)

    Minnesota Department of Natural Resources — 1:100,000 scale geomorphology data describing a wide variety of conditions related to surficial geology within a hierarchical classification scheme that was devised...

  5. The reenchantment of geomorphology (United States)

    Baker, V. R.; Twidale, C. R.


    Much of modern Geomorphology lacks the enchantment that the science possessed a century ago. Practical and philosophical impediments are thwarting modern attempts to achieve a satisfying understanding of landforms and their genesis. In recent years, even the security of geomorphologists' academic bases has been threatened within the cognate disciplines of Geography and Geology. During the 1960s these fields experienced so-called "scientific revolutions," which many geomorphologists either uncritically embraced or assumed to be irrelevant. While commendable in spirit, progressive initiatives to establish research traditions in landscape evolution, climatic geomorphology, and process studies all encountered fundamental limitations as unifying themes. More disturbing are ideological impositions that advocate geomorphological concentration on timeless, theoretical, or utilitarian problems. While facilitating precision of explanation and prediction, various geoideological bandwagons may stifle creativity, insight, and intellectual satisfaction. Most insidious is the substitution of elegantly structured methodology and theory for spontaneity, serendipity, and common sense. Hope for the reenchantment of Geomorphology lies in a new connectedness to nature that will facilitate the identification of anomalies and the formulation of outrageous hypotheses of causation. In the words of William Morris Davis, "…violence must be done to many of our accepted principles." Examples of such ideas may be found in fringe areas of the discipline, including planetary geomorphology, tectonic geomorphology, and denudation chronology with emphasis on ancient paleosurfaces. Geomorphologists should consider inverting their belief that they are achieving progressive (timebound) understanding of invariant (timeless) laws in nature. Rather, they may choose a geophysiological view in which the richness of natural history is revealed in a timeless conversation with the Earth.

  6. The Modern Geomorphological Map

    NARCIS (Netherlands)

    Seijmonsbergen, A.C.; Switzer, A.; Kennedy, D.M.


    Classical geomorphological maps are representations of the spatial distribution of landforms, materials and of the processes responsible for their formation, in a single paper map. They contain a wealth of information that is generally documented with the aid of symbol and color legends. Uniformity

  7. Geomorphological research in Spain


    Gutiérrez, Francisco; Harvey, A.; García-Ruiz, José María; Silva, Pablo; Cendrero, Antonio


    We are very grateful to all the referees for their indispensable and unselfish work that greatly contributed to the improvement of the quality of the papers. The Department of the Environment and the Department of Science, Technology and University of the Aragón Government, as well as the Innovation Ministry of the Spanish Government (CGL2011-12465), provided financial support to organise the scientific meeting “Geomorphological Research in Spain” (Zaragoza, September, 2011). We thank the Int...

  8. Geomorphology and River Management

    Directory of Open Access Journals (Sweden)



    Full Text Available Engineering-dominated practices, visible in a "command and control" outlook on natural systems, have induced enormous damage to the environment. Biodiversity losses and declining provision of ecosystem services are testimony to the non-sustainable outcomes brought about by such practices. More environmentally friendly approaches that promote a harmonious relationship between human activities and nature are required. Moves towards an "ecosystem approach" to environmental management require coherent (integrative scientific guidance. Geomorphology, the study of the form of the earth, provides a landscape template with which to ground this process. This way of thinking respects the inherent diversity and complexity of natural systems. Examples of the transition toward such views in environmental practice are demonstrated by the use of science to guide river management, emphasising applications of the River Styles framework.

  9. Inlet Geomorphology Evolution Work Unit (United States)


    the expected behavior and benefits of nearshore placement. Nearshore placement studies have been documented in two journal papers, one technical...Coastal Inlets Research Program Inlet Geomorphology Evolution Work Unit The Inlet Geomorphology Evolution work unit of the CIRP develops methods...sensing measurements, and USACE projects to create valuable guidance that address geomorphic questions. The present focus of the work unit is a common

  10. Geomorphology of coal seam fires (United States)

    Kuenzer, Claudia; Stracher, Glenn B.


    Coal fires occur in underground natural coal seams, in exposed surface seams, and in coal storage or waste piles. The fires ignite through spontaneous combustion or natural or anthropogenic causes. They are reported from China, India, USA, South Africa, Australia, and Russia, as well as many other countries. Coal fires lead to loss of a valuable resource (coal), the emission of greenhouse-relevant and toxic gases, and vegetation deterioration. A dangerous aspect of the fires is the threat to local mines, industries, and settlements through the volume loss underground. Surface collapse in coal fire areas is common. Thus, coal fires are significantly affecting the evolution of the landscape. Based on more than a decade of experience with in situ mapping of coal fire areas worldwide, a general classification system for coal fires is presented. Furthermore, coal seam fire geomorphology is explained in detail. The major landforms associated with, and induced by, these fires are presented. The landforms include manifestations resulting from bedrock surface fracturing, such as fissures, cracks, funnels, vents, and sponges. Further manifestations resulting from surface bedrock subsidence include sinkholes, trenches, depressions, partial surface subsidence, large surface subsidence, and slides. Additional geomorphologic coal fire manifestations include exposed ash layers, pyrometamorphic rocks, and fumarolic minerals. The origin, evolution, and possible future development of these features are explained, and examples from in situ surveys, as well as from high-resolution satellite data analyses, are presented. The geomorphology of coal fires has not been presented in a systematic manner. Knowledge of coal fire geomorphology enables the detection of underground coal fires based on distinct surface manifestations. Furthermore, it allows judgments about the safety of coal fire-affected terrain. Additionally, geomorphologic features are indicators of the burning stage of fires

  11. Contemporary research in aeolian geomorphology (United States)

    Bauer, B. O.


    The first International Conference on Aeolian Geomorphology (ICAR) was held in 1986, and every four years since then, aeolian geomorphologists from around the world have assembled to discuss their research and to showcase recent advancements in understanding and modeling of aeolian processes. A content analysis of the "Bibliography of Aeolian Research" [Stout, J.E., Warren, A., Gill, T.E., 2009. Publication trends in aeolian research: An analysis of the Bibliography of Aeolian Research. Geomorphology 105, 6-17 (this volume)] shows that the number of publications on aeolian topics has increased exponentially from the mid-20th Century with approximately 50 publications per year to about 500 publications per year when the first ICAR was held, to almost 1000 publications per year currently. Areas of focus have shifted historically from initial concerns with aeolian erosion and dust events as isolated phenomenon of localized curiosity or only regional importance, to comprehensive physically-based investigations and modeling of the mechanics of aeolian transport. Recently, more applied studies have been motivated by the recognition of the importance of aeolian processes to dust emissions into the atmosphere (with relevance for human health and for meteorological conditions and climate change) and within regional management contexts (especially on coasts where impending sea-level rise is of great concern and in arid and semi-arid environments given the dependence of sediment surface stability and remobilization on meteorological and ecological conditions). Aeolian geomorphology is a rapidly growing sub-discipline of Geomorphology that offers rich opportunities for interdisciplinary collaborations with colleagues from the Atmospheric Sciences, Climatology, Sedimentology, Quaternary Geology, Fluid Mechanics, Physics, Mathematics, Computer Science, Physical Geography, Ecology, and Agricultural Sciences, as well as our counterparts in fluvial, coastal, and arid

  12. Geomorphological factors of flash floods (United States)

    Kuznetsova, Yulia


    Growing anthropogenic load, rise of extreme meteorological events frequency and total precipitation depth often lead to increasing danger of catastrophic fluvial processes worldwide. Flash floods are one of the most dangerous and less understood types of them. Difficulties of their study are mainly related to short duration of single events, remoteness and hard access to origin areas. Most detailed researches of flash floods focus on hydrological parameters of the flow itself and its meteorological factors. At the same time, importance of the basin geological and geomorphological structure for flash floods generation and the role they play in global sediment redistribution is yet poorly understood. However, understanding and quantitative assessment of these features is a real basis for a complete concept of factors, characteristics and dynamics of flash floods. This work is a review of published data on flash floods, and focuses on the geomorphological factors of the phenomenon. We consider both individual roles and interactions between different geomorphological features (the whole basin parameters, characteristics of the single slopes and valley bottom). Special attention is paid to critical values of certain factors. This approach also highlights the gaps or less studied factors of flash floods. Finally, all data is organized into a complex diagram that may be used for flash floods modeling. This also may help to reach a new level of flash flood predictions and risk assessment.

  13. Geomorphology of Minnesota - Isolated Landform Structures (United States)

    Minnesota Department of Natural Resources — Geomorphology of Minnesota - Isolated Landform Structures are essentially cartographic arcs representing isolated glacial features that were mapped in conjunction...

  14. ergodicity and chaos in geomorphology (United States)

    Aadel, S.; Gaiumi, M.


    The past three dicades can be considered as a period in which the fundamentals of scientific epistemology have been subjected to drastic revision.The dissemination of the general theory of systems in 1972 , one year after the death of ludwing von Berthalanfi , the proposition of fuzzy logic by Zade, and the foemulation of chaos theory in 1986 by Harison and Biswas allserved to explode the myth that scientific thought was invulnerable. This paper , which has resulted from the theoretical investigation of project based on the paraglicial sediment and glacial evidence on the Zagros-pishkoh to explain the elements of chaos theory and their compatibility with ergodic geomorphology

  15. Geomorphological risk analysis in the Republic of Belarus



    Romanenko V. GIS-Mapping and Assessment of Geomorphological Risk in Belarus / V. Romanenko, D. Kurlovich // The geomorphology of natural hazards: mapping, analysis and prevention. Abstract book. 17th Joint Geomorphological Meeting, Liege (Belgium). 1-3 July 2014. – Liege. – P. 116. In the present study an assessment of geomorphological risk in the Republic of Belarus has been made. Geomorphological districts (according to geomorphological zoning) were the objects of the research.

  16. Introduction to the special issue: Planetary geomorphology (United States)

    Burr, Devon M.; Howard, Alan D.


    Planetary geomorphology is the study of extraterrestrial landscapes. In recognition of the promise for productive interaction between terrestrial and planetary geomorphologists, the 45th annual Binghamton Geomorphology Symposium (BGS) focused on Planetary Geomorphology. The aim of the symposium was to bring planetary and terrestrial geomorphologists together for symbiotic and synthetic interactions that would enrich both subdisciplines. In acknowledgment of the crucial role of terrestrial field work in planetary geomorphology and of the BGS tradition, the symposium began with a field trip to the Appalachian Mountains, followed by a dinner talk of recent results from the Mars Surface Laboratory. On Saturday and Sunday, the symposium was organized around major themes in planetary geomorphology, starting with the geomorphic processes that are most common in our Solar System-impact cratering, tectonism, volcanism-to set the stage for other geomorphic processes, including aeolian, fluvial, lacustrine, and glacial/polar. On Saturday evening, the banquet talk provided an historical overview of planetary geomorphology, including its roots in the terrestrial geosciences. The symposium concluded with a full-afternoon tutorial on planetary geomorphologic datasets. This special issue of Geomorphology consists of papers by invited authors from the 2014 BGS, and this introduction provides some context for these papers.

  17. Geomorphological Hazards in Los Angeles (United States)

    Hadley, Richard F.

    This is a topical book that deals with the geomorphological and geological engineering problems associated with hillslope processes and sediment transport in the Los Angeles metropolitan area. There are few large cities in the United States where the problems of urban growth include such a distinctive physical environment, as well as the potential hazards of brush fires, earthquakes, and floods that occur in Los Angeles. The research and data used in the book are restricted to Los Angeles County and cover the period 1914-1978. The author has done a commendable job of synthesizing a large mass of data from diverse sources, including federal, state, and local agency reports, plus data from private groups such as professional technical societies and consultants.

  18. Complex systems in aeolian geomorphology (United States)

    Baas, Andreas C. W.


    Aeolian geomorphology provides a rich ground for investigating Earth surface processes and landforms as complex systems. Sand transport by wind is a classic dissipative process with non-linear dynamics, while dune field evolution is a prototypical self-organisation phenomenon. Both of these broad areas of aeolian geomorphology are discussed and analysed in the context of complexity and a systems approach. A feedback loop analysis of the aeolian boundary-layer-flow/sediment-transport/bedform interactions, based on contemporary physical models, reveals that the system is fundamentally unstable (or at most meta-stable) and likely to exhibit chaotic behaviour. Recent field-experimental research on aeolian streamers and spatio-temporal transport patterns, however, indicates that sand transport by wind may be wholly controlled by a self-similar turbulence cascade in the boundary layer flow, and that key aspects of transport event time-series can be fully reproduced from a combination of (self-organised) 1/ f forcing, motion threshold, and saltation inertia. The evolution of various types of bare-sand dunes and dune field patterns have been simulated successfully with self-organising cellular automata that incorporate only simplified physically-based interactions (rules). Because of their undefined physical scale, however, it not clear whether they in fact simulate ripples (bedforms) or dunes (landforms), raising fundamental cross-cutting questions regarding the difference between aeolian dunes, impact ripples, and subaqueous (current) ripples and dunes. An extended cellular automaton (CA) model, currently under development, incorporates the effects of vegetation in the aeolian environment and is capable of simulating the development of nebkhas, blow-outs, and parabolic coastal dunes. Preliminary results indicate the potential for establishing phase diagrams and attractor trajectories for vegetated aeolian dunescapes. Progress is limited, however, by a serious lack of

  19. Association and determinacy in geomorphology (United States)

    Leopold, Luna Bergere; Langbein, Walter Basil; Albritton, Claude C.


    You find a rock. It looks like an ordinary piece of flint, broken and rough. On a part of it is a patina whose soft grey color contrasts with the shiny brownish surfaces of conchoidal fracture. You could have found this rock in nearly any kind of an environment almost anyplace in the world. There is nothing distinctive about it.You hand this same piece of rock to a colleague and ask what he can make of it. He considers it soberly before he says, “You know, that could be an artifact.” There springs to mind then a picture of a primitive man, squatting barefoot before a fire warming his hands. The firelight casts his shadow against the cliff below which he crouches. The difference between the reaction before and after the passing thought that this might indeed be the tool of ancient man is the difference between mild disinterest and a kaleidoscope of mental pictures. This difference reflects differences in the associations of thoughts. The present essay is concerned with how associations are used in geologic reasoning, and then with certain philosophic considerations which seem to be influencing the methodology and direction of geomorphology.

  20. Geomorphological characterization of conservation agriculture (United States)

    Tarolli, Paolo; Cecchin, Marco; Prosdocimi, Massimo; Masin, Roberta


    characterise the surface morphology. For each of derived Digital Elevation Model, seven morphometric indexes, such as slope, curvature, flow direction, contributing area, roughness, and connectivity was calculated. We showed then the variations of the morphology in the areas converted to the conservation agriculture, and, consequently, a possible modification of processes such as erosion and runoff. The results suggested that the agricultural surfaces interested by no-tillage practices are different from those tilled with conventional systems. The topography is rougher, with chaotic flow directions, and more concave areas, thus resulting in potential water storages, mitigating the intensity of soil erosion and runoff processes. On the other hand, the topography of traditional tillage area is more regular and smooth, with flow directions that tend to follow the same direction on the surface. These results are a novelty in the Earth Science and Agronomy: we demonstrated and quantified, from the geomorphological point of view, the potential role of conservative agriculture in mitigating, not only land degradation phenomena, but also the distribution of pollutants, and rainfall-runoff processes. References Prosdocimi, M., Tarolli, P., Cerdà, A. (2016). Mulching practice for reducing soil water erosion: A review. Earth-Science Reviews, 161, 191-203. Prosdocimi, M., Burguet, M., Di Prima, S., Sofia, G., Terol, E, Rodrigo Comino J., Cerdà, A., Tarolli, P. (2017). Rainfall simulation and Structure-from-Motion photogrammetry for the analysis of soil water erosion in Mediterranean vineyards. Science of the Total Environment, 574, 204-215. Tarolli, P., Sofia G. (2016). Human topographic signatures and derived geomorphic processes across landscapes, Geomorphology, 255, 140-161.

  1. Geomorphology and the World Wide Web (United States)

    Shroder, John F.; Bishop, Michael P.; Olsenholler, Jeffrey; Craiger, J. Philip


    The Internet and the World Wide Web have brought many dimensions of new technology to education and research in geomorphology. As with other disciplines on the Web, Web-based geomorphology has become an eclectic mix of whatever material an individual deems worthy of presentation, and in many cases is without quality control. Nevertheless, new electronic media can facilitate education and research in geomorphology. For example, virtual field trips can be developed and accessed to reinforce concepts in class. Techniques for evaluating Internet references helps students to write traditional term papers, but professional presentations can also involve student papers that are published on the Web. Faculty can also address plagiarism issues by using search engines. Because of the lack of peer review of much of the content on the Web, care must be exercised in using it for reference searches. Today, however, refereed journals are going online and can be accessed through subscription or payment per article viewed. Library reference desks regularly use the Web for searches of refereed articles. Research on the Web ranges from communication between investigators, data acquisition, scientific visualization, or comprehensive searches of refereed sources, to interactive analyses of remote data sets. The Nanga Parbat and the Global Land Ice Measurements from Space (GLIMS) Projects are two examples of geomorphologic research that are achieving full potential through use of the Web. Teaching and research in geomorphology are undergoing a beneficial, but sometimes problematic, transition with the new technology. The learning curve is steep for some users but the view from the top is bright. Geomorphology can only prosper from the benefits offered by computer technologies.


    Directory of Open Access Journals (Sweden)



    Full Text Available Jiu Defile has a length of 33 km and is located in the Southern Carpathians, between Parâng Mountains (east and Vâlcan Mountains (west. This paper stars from the analysis of field mapping and measurements (based on topographic maps, scale of 1:25 000, and data from local institutions and other sources (web, press. In Jiu Defile, geomorphological hazards results from the combined action of meteorological conditions and other factors such as geology, geomorphology and socio-economic development. They may affect transport infrastructure, which is at risk especially in spring and summer.

  3. Landforms as geodiversity (geomorphological natural heritage

    Directory of Open Access Journals (Sweden)

    Bojan Erhartič


    Full Text Available This paper highlights different values of the landforms as part of geomorphological heritage and helps to put forward the term geodiversity in Slovenia. The article provides reasons to value geodiversity and is followed by a discussion of the specific types of values: intrinsic, cultural, aesthetic, socio-economic, functional, geosystem, research and educational.

  4. Geomorphosites and the history of geomorphology (United States)

    Giusti, Christian


    Geomorphosites are geosites of geomorphological significance, with a now well admitted distinction between central or scientific values on the one hand, and additional values such as ecological, economical or aesthetical values on the other hand. Among the scientific values, some are directly linked to the climatic forcings through geomorphological processes in the case of active geomorphosites, for example the meaning of a waterfall in a post-glacial trough valley. In the case of passive geomorphosites, the central values rather lie in structural features, ancient landforms, inherited regoliths such as the clay-with-flints of the Chalklands of Southern England and Northern France. Sometimes, the scientific value is not fully determined by the type of geomorphosite, active or passive, but rather by the fact this geosite has a special importance concerning the history of the Earth sciences, especially in geomorphology. This is well exemplified with the famous case of the Nant d'Arpenaz waterfall S-folds in the lower Arve valley between Geneva and Chamonix, first described by Horace Benedict de Saussure in 1774 and invoked to explain the formation of the Alps by folding. This structural geosite (history of tectonics) is also a geomorphosite. Concerning geomorphology, the current Nant d'Arpenaz waterfall is quite similar to the Pissevache waterfall in the Rhone valley: they are both examples of postglacial geomorphosites due to hanging valleys. When erosion is more advanced narrow gorges appear, for example Diosaz gorge (Haute-Savoie, France) or Dailley, Trient and Triège gorges (Valais, Switzerland). All these geomorphosites (main trough valleys, tributary valleys, waterfalls and postglacial gorges) were studied by pionneers of fluvial and glacial geomorphology such as Jean Bruhnes and Emmanuel de Martonne before World War I. The former has played an important role at the University of Fribourg (Switzerland) and has devoted many studies about the potholes and eddies

  5. The concept of transport capacity in geomorphology (United States)

    Wainwright, John; Parsons, Anthony J.; Cooper, James R.; Gao, Peng; Gillies, John A.; Mao, Luca; Orford, Julian D.; Knight, Peter G.


    The notion of sediment-transport capacity has been engrained in geomorphological and related literature for over 50 years, although its earliest roots date back explicitly to Gilbert in fluvial geomorphology in the 1870s and implicitly to eighteenth to nineteenth century developments in engineering. Despite cross fertilization between different process domains, there seem to have been independent inventions of the idea in aeolian geomorphology by Bagnold in the 1930s and in hillslope studies by Ellison in the 1940s. Here we review the invention and development of the idea of transport capacity in the fluvial, aeolian, coastal, hillslope, débris flow, and glacial process domains. As these various developments have occurred, different definitions have been used, which makes it both a difficult concept to test, and one that may lead to poor communications between those working in different domains of geomorphology. We argue that the original relation between the power of a flow and its ability to transport sediment can be challenged for three reasons. First, as sediment becomes entrained in a flow, the nature of the flow changes and so it is unreasonable to link the capacity of the water or wind only to the ability of the fluid to move sediment. Secondly, environmental sediment transport is complicated, and the range of processes involved in most movements means that simple relationships are unlikely to hold, not least because the movement of sediment often changes the substrate, which in turn affects the flow conditions. Thirdly, the inherently stochastic nature of sediment transport means that any capacity relationships do not scale either in time or in space. Consequently, new theories of sediment transport are needed to improve understanding and prediction and to guide measurement and management of all geomorphic systems.

  6. Population vulnerability to geomorphological hazards in Reghin Hills.

    Directory of Open Access Journals (Sweden)

    I. A. Irimus


    Full Text Available Vulnerability assessment of population to the actual geomorphological processes are an essential tool in disaster management planning, assessment and loss estimation, and is an important aspect in geomorphological risk reduction to the safety of the population, settlements and human activities. In this paper we propose an analysis of Reghin Hills′ population vulnerability to the current geomorphological processes through physical, spatial. and demographic indicators.

  7. Smart "geomorphological" map browsing - a tale about geomorphological maps and the internet (United States)

    Geilhausen, M.; Otto, J.-C.


    With the digital production of geomorphological maps, the dissemination of research outputs now extends beyond simple paper products. Internet technologies can contribute to both, the dissemination of geomorphological maps and access to geomorphologic data and help to make geomorphological knowledge available to a greater public. Indeed, many national geological surveys employ end-to-end digital workflows from data capture in the field to final map production and dissemination. This paper deals with the potential of web mapping applications and interactive, portable georeferenced PDF maps for the distribution of geomorphological information. Web mapping applications such as Google Maps have become very popular and widespread and increased the interest and access to mapping. They link the Internet with GIS technology and are a common way of presenting dynamic maps online. The GIS processing is performed online and maps are visualised in interactive web viewers characterised by different capabilities such as zooming, panning or adding further thematic layers, with the map refreshed after each task. Depending on the system architecture and the components used, advanced symbology, map overlays from different applications and sources and their integration into a Desktop GIS are possible. This interoperability is achieved through the use of international open standards that include mechanisms for the integration and visualisation of information from multiple sources. The portable document format (PDF) is commonly used for printing and is a standard format that can be processed by many graphic software and printers without loss of information. A GeoPDF enables the sharing of geospatial maps and data in PDF documents. Multiple, independent map frames with individual spatial reference systems are possible within a GeoPDF, for example, for map overlays or insets. Geospatial functionality of a GeoPDF includes scalable map display, layer visibility control, access to attribute

  8. The most-cited works in Geomorphology (United States)

    Doyle, Martin W.; Julian, Jason P.


    We conducted a review and analysis of the references cited in articles published (1995-2004) in the journal Geomorphology and also solicited comments from the authors of the most-cited works on their major influences. Of the 31,696 unique works cited in the journal, only 22 were referenced at least 20 times, with the vast majority (92%) cited only once or twice. We divided the citations into the 10 most-cited books (i.e., complete volumes) and 10 most-cited papers (i.e., journal articles, book chapters, reports). A total of 23 different researchers were responsible for the 20 works, with one (Wolman) being an author or co-author of a quarter of them. Seven of the ten most-cited papers were based on work in the USGS in the mid-twentieth century, indicating a particularly fruitful time of geomorphic research and a particularly important cohort of scientists. Based on our citation analysis and author commentaries, we suggest that classic works in geomorphology are most likely to be those that provide useful knowledge and those that incorporate interdisciplinary perspectives.

  9. 4D geomorphological evolution of intertropical islands (United States)

    Pastier, Anne-Morwenn; Bezos, Antoine; Husson, Laurent; Pedoja, Kevin; Arias, Camilo; Elliot, Mary; Lacroix, Pascal; Imran, Andi Muhammad


    Coral reef terraces record joint variations of sea level and surface elevation. U/Th ratings on corals along with topographic/bathymetric profiles and eustatic reconstitutions allow to locally determine the vertical rate of ground motion, while numerical modelling of reef sequences allows to unravel the processes controlling the architecture of sequences, and high-resolution DEMs facilitates the detailed mapping of the sequences of reef terraces. Alltogether, these methods allow to extrapolate the local vertical rates towards an unprecedented resolution for 4D kinematics. We applied our method to uplifting islands of the tectonically active Buton Archipelago, SE Sulawesi, Indonesia. The area undergoes a general uplift revealed by the ubiquitous occurrence of uplifted and folded reef sequences. We dated some 40 samples using U/Th, acquired sonar and dGPS profiles, and constructed high-res DEMs (Pleiades). Local vertical rates (from 0.2 to 0.28 mm/yr) were determined. Detailed geomorphological mapping of the lateral variations of the terraces are converted into time and space variations of uplift rates. Extrapolating the higher, undated terraces permits to reconstruct the overall 4D geomorphology history over the last Ma. In turns, these results give a unique view on the structural kinematics.

  10. Laser Scanning Applications in Fluvial Geomorphology (United States)

    Alho, P.


    During recent decades, the use of high-resolution laser scanning data in fluvial studies has rapidly increased. Airborne laser scanning (ALS) can be used to extensively map riverine topography. Laser scanning data have great potential to improve the effectiveness of topographical data acquisition and the accuracy and resolution of DTMs (Digital Terrain Models) needed in fluvial geomorphology. Airborne Laser Scanning (ALS) is applicable for mapping areas varying from reach to catchment scale and these data are, therefore, particularly suitable, especially for hydraulic modelling, mapping of flood inundation, and the detection of macro-scale fluvial geomorphology. With Terrestrial Laser Scanning (TLS) a spatial resolution of less than 1 mm and a range accuracy of few millimetres can be achieved. Mobile Laser Scanning (MLS) enables a remarkably faster survey approach compared to the conventional TLS method. One of the newest applications of MLS approaches involves a boat/cart/backpack -based mobile mapping system. This set-up includes laser scanning and imaging from a platform moving along a river course or floodplain and may be used to expand the spatial extent of terrestrial scanning. Detailed DTMs derived from laser scanning data can be used to improve the recognition of fluvial landforms, the geometric data of hydraulic modelling, and the estimation of flood inundation extents and the associated fluvial processes. Fluvial environments also offer challenges for the application of laser scanning techniques. Factors such as vegetation cover, terrain undulation, coarse surface materials and water surfaces may distort a laser scanning survey.

  11. Geomorphological development of Eastern Mongolian plain, Mongolia (United States)

    khukhuudei, Ulambadrakh; otgonbayar, Orolzodmaa


    Several summaries and investigations of the geomorphological description and feature for Eastern Mongolian plain (EMP), the one of the largest geomorphological district, fully covering east side of Mongolia (Murzayev, 1949; Vlodavets, 1950, 1955; Marinov, Khasin, 1954; Marinov, 1966; Nikolayeva, 1971; Selivanov, 1972; Chichagov, 1974, 1976; Grigorov, 1975; Korjuyev, 1982; Syirnev, 1982, 1984) had been publishing continuously. But literature for geomorphology of EMP have been not appeared during over the past 20 years. However, we re-combine the geomorphological development of EMP, according to the results of many publications for surrounding regions of Russia and China and unpublished maps. Main morphology of EMP has the plain, containing with aeolian, fluvial and lacustrine landforms. Plain morphology defined that denudation plains to North Kherlen, South Kherlen, Baruun Urt, Uulbayan, Delgerekh and other which developed on the Paleozoic rocks, layered plain to Choibalsan, Tamsag, Ongon, Gert, Sumiin nuur and Torey- on the Late Cretaceous and Neogene sediments and accumulation plain with alluvial and lacustrine origin such as Menen, Buir nuur, Tamsagbulag, Khalzan and other. These plains of EMP related with tectonics and structure of region and inherited the development of the Mesozoic, particularly Late Mesozoic structure. Large basins of EMP are Tamsag, Choibalsan and Torey and other small basins - from 7-10 km to 25-30 km width and rather a several 10 km extend, cutting a basement. The origin of plain morphology for EMP is interpreted as two main stages of the geomorphological development model, based on geology. In first stage or Late Jurassic (?) - Lower Cretaceous period, there was developed rift basin, then, in second stage or since Late Cretaceous period, plain morphology originated from the intermountain basin that dominated by exogenic process and kept in current EMP area. Data relevant to the development history of EMP are following. 1. Rift volcanism

  12. Surficial geological tools in fluvial geomorphology (United States)

    Jacobson, Robert B.; O'connor, James; Oguchi, Takashi


    Environmental scientists are increasingly asked how rivers and streams have been altered by past environmental stresses, whether rivers are subject to physical or chemical hazards, how they can be restored and how they will respond to future environmental changes. These questions present substantive challenges to the discipline of fluvial geomorphology as they require a long-term understanding of river-system dynamics. Complex and non-linear responses of rivers to environmental stresses indicate that synoptic or short-term historical views of rivers will often give an incomplete understanding. Fluvial geomorphologists can address questions involving complex river behaviours by drawing from a tool box that includes the principles and methods of geology applied to the surficial geological record. A central concept in Earth Sciences holds that ‘the present is the key to the past’ (Hutton 1788, cited in Chorley et al. 1964), that is, understanding of current processes permits the interpretation of past deposits. Similarly, an understanding of the past can be key to predicting the future. A river’s depositional history can be indicative of trends or episodic behaviours that can be attributed to particular environmental stresses or forcings. Its history may indicate the role of low-frequency events such as floods or landslides in structuring a river and its floodplain or a river’s depositional history can provide an understanding of its natural characteristics to serve as a reference condition for assessments and restoration. However, the surficial geological record contained in river deposits is incomplete and biased and it presents numerous challenges of interpretation. The stratigraphic record in general has been characterized as ‘ … a lot of holes tied together with sediment’ (Ager 1993). Yet this record is critical in the development of integrated understanding of fluvial geomorphology because it provides information that is not available from other


    Directory of Open Access Journals (Sweden)

    M. Maghsoudi


    Full Text Available Geomorphology is briefly the study of landforms and their formative processes on the surface of the planet earth as human habitat. The landforms evolution and the formative processes can best be studied by technologies with main application in study of elevation. Interferometric Synthetic Aperture Radar (InSAR is the appropriate technology for this application. With phase differences calculations in radar waves, the results of this technology can extensively be interpreted for geomorphologic researches. The purpose of the study is to review the geomorphologic studies using InSAR and also the technical studies about InSAR with geomorphologic interpretations. This study states that the InSAR technology can be recommended to be employed as a fundamental for geomorphology researches.

  14. Geomorphology and habitat diversity in the Pantanal. (United States)

    Mercante, M A; Rodrigues, S C; Ross, J L S


    The present study deals with the inter-relations in the relief which forms the Bacia do Alto Rio Paraguay (BAP) in mid-west Brazil. The overall aim is to discuss the relationship between relief forms and the biodiversity of the Pantanal. The BAP is a natural environmental system with contrasts in two of the compartments on which it is formed: the plateau, the most elevated compartment, highly transformed by human activities, and the plain which forms the Pantanal, which is more preserved and less transformed in relation to productive activities. The analysis was performed based on publications with a geomorphologic focus, examining the different relief units of the BAP and the dynamics of the revealing processes of landscape change which the Pantanal has undergone since the end of the Pleistocene.

  15. Planetary geomorphology: Some historical/analytical perspectives (United States)

    Baker, V. R.


    Three broad themes from the history of planetary geomorphology provide lessons in regard to the logic (valid reasoning processes) for the doing of that science. The long controversy over the origin of lunar craters, which was dominated for three centuries by the volcanic hypothesis, provides examples of reasoning on the basis of authority and a priori presumptions. Percival Lowell's controversy with geologists over the nature of linear markings on the surface of Mars illustrates the role of tenacity in regard to the beliefs of some individual scientists. Finally, modern controversies over the role of water in shaping the surface of Mars illustrate how the a priori method, i.e., belief produced according to reason, can seductively cloud the scientific openness to the importance of brute facts that deviate from a prevailing paradigm.

  16. Coastal geomorphology through the looking glass (United States)

    Sherman, Douglas J.; Bauer, Bernard O.


    Coastal geomorphology will gain future prominence as environmentally sound coastal zone management strategies, requiring scientific information, begin to supplant engineered shoreline stabilization schemes for amelioration of coastal hazards. We anticipate substantial change and progress over the next two decades, but we do not predict revolutionary advances in theoretical understanding of coastal geomorphic systems. Paradigm shifts will not occur; knowledge will advance incrementally. We offer predictions for specific coastal systems delineated according to scale. For the surf zone, we predict advances in wave shoaling theory, but not for wave breaking. We also predict greater understanding of turbulent processes, and substantive improvements in surf-zone circulation and radiation stress models. Very few of these improvements are expected to be incorporated in geomorphic models of coastal processes. We do not envision improvements in the theory of sediment transport, although some new and exciting empirical observations are probable. At the beach and nearshore scale, we predict the development of theoretically-based, two- and three-dimensional morphodynamical models that account for non-linear, time-dependent feedback processes using empirically calibrated modules. Most of the geomorphic research effort, however, will be concentrated at the scale of littoral cells. This scale is appropriate for coastal zone management because processes at this scale are manageable using traditional geomorphic techniques. At the largest scale, little advance will occur in our understanding of how coastlines evolve. Any empirical knowledge that is gained will accrue indirectly. Finally, we contend that anthropogenic influences, directly and indirectly, will be powerful forces in steering the future of Coastal Geomorphology. "If you should suddenly feel the need for a lesson in humility, try forecasting the future…" (Kleppner, 1991, p. 10).

  17. Kinds and problems of geomorphological explanation (United States)

    Cox, Nicholas J.


    What characterises satisfactory explanations in geomorphology is a key methodological question deserving continued analysis. In turn it raises the issue of the role played by methodology within the science. At its best, methodology can provide helpful distinctions, identify key issues and yield guidance for researchers. The substantive context for debates on explanation is the apparent complexity and difficulty of geomorphology as a science, which is arguably no greater than that of other Earth or environmental sciences. The logical view of explanation dominant in the 1950s and 1960s still has value, but a broader view is needed of explanations, related to the questions geomorphologists (and others) ask and to the answers that they find interesting. Answers may be sought in terms of purpose, history, mechanisms and statistics. Arguments over what is supposed to be reductionism can be clarified by underlining that both micro- and macro-explanations may be helpful. Although many geomorphologists aspire to mechanistic explanations, they often stop short at statistical explanations, making use of convenient functional forms such as power laws. Explanations have both social and psychological dimensions, the former much stressed in history of science and recent science studies, the latter deserving greater emphasis at present. Complicated models raise the question of how far it can be said that geomorphologists understand them in totality. A bestiary of poor explanations is needed, so that geomorphologists are not seduced by weak arguments and because they often serve as steps towards better explanations. Circular arguments, ad hoc explanations, and mistaking the name of the problem for the solution are cases in point.

  18. Causal Loop Analysis of coastal geomorphological systems (United States)

    Payo, Andres; Hall, Jim W.; French, Jon; Sutherland, James; van Maanen, Barend; Nicholls, Robert J.; Reeve, Dominic E.


    As geomorphologists embrace ever more sophisticated theoretical frameworks that shift from simple notions of evolution towards single steady equilibria to recognise the possibility of multiple response pathways and outcomes, morphodynamic modellers are facing the problem of how to keep track of an ever-greater number of system feedbacks. Within coastal geomorphology, capturing these feedbacks is critically important, especially as the focus of activity shifts from reductionist models founded on sediment transport fundamentals to more synthesist ones intended to resolve emergent behaviours at decadal to centennial scales. This paper addresses the challenge of mapping the feedback structure of processes controlling geomorphic system behaviour with reference to illustrative applications of Causal Loop Analysis at two study cases: (1) the erosion-accretion behaviour of graded (mixed) sediment beds, and (2) the local alongshore sediment fluxes of sand-rich shorelines. These case study examples are chosen on account of their central role in the quantitative modelling of geomorphological futures and as they illustrate different types of causation. Causal loop diagrams, a form of directed graph, are used to distil the feedback structure to reveal, in advance of more quantitative modelling, multi-response pathways and multiple outcomes. In the case of graded sediment bed, up to three different outcomes (no response, and two disequilibrium states) can be derived from a simple qualitative stability analysis. For the sand-rich local shoreline behaviour case, two fundamentally different responses of the shoreline (diffusive and anti-diffusive), triggered by small changes of the shoreline cross-shore position, can be inferred purely through analysis of the causal pathways. Explicit depiction of feedback-structure diagrams is beneficial when developing numerical models to explore coastal morphological futures. By explicitly mapping the feedbacks included and neglected within a

  19. Geomorphology and geomorphological heritage of the Ifrane-Azrou region (Middle Atlas, Morocco) (United States)

    de Waele, Jo; Melis, Maria Teresa


    Geomorphological heritage is a widely used term in European and North-American countries, but is still scarcely mentioned in Africa. Nevertheless, the attractiveness of the African countries is often intimately connected to its breathtaking and endless geological landscapes. Morocco is one of those countries that has the widest diversity in landscapes and landforms, ranging from the Mediterranean and Atlantic coasts over the Rif, Middle Atlas, High Atlas and Anti-Atlas mountain chains to the great rocky and sandy deserts in the South. A wide variety of geological units hosting different types of important economic mineral deposits cover a temporal range from Late Precambrian to Quaternary. A detailed geomorphological study has been carried out in the region of Ifrane and Azrou (Middle Atlas, Central Morocco) using a combination of high resolution satellite data and direct field observations integrated by geological maps and scientific literature. In order to describe and evaluate the geomorphological heritage of this area, 40 geomorphosites have been selected comprising springs, karst landforms (polje, dolines, caves, sinkholes, stone forests, cryptokarstic dolines), carbonate depositional landforms (travertines and waterfalls), fluvial landforms (meanders, canyons, palaeo-valleys, etc.), structural landforms (triangular facets, hogbacks, cuestas, residual outcrops, etc.) and volcanic landforms (volcanoes, caldeira, pyroclastic cones, lava tube). The results of this research have been summarised in a thematic map, representing the geomorphosites related to various landscape units.

  20. Karst geomorphology: From hydrological functioning to palaeoenvironmental reconstructions. Part II (United States)

    De Waele, Jo; Gutierrez, Francisco; Audra, Philippe


    In January 2015, the first part of the special issue on karst, entitled "Karst geomorphology: From hydrological functioning to palaeoenvironmental reconstructions" was published (Geomorphology, Vol. 229). This second part of the special issue comprises seven research papers covering a broad geographical canvas including Japan, Slovenia, France, Spain, Croatia, and Poland-Ukraine. Both issues mainly emanate from the contributions presented in the Karst session of the 8th International Conference of Geomorphology (International Association of Geomorphologists), held in Paris in August 2013, enriched with some invited papers.

  1. Should precise numerical dating overrule glacial geomorphology? (United States)

    Winkler, Stefan


    Numerical age dating techniques, namely different types of terrestrial cosmogenic nuclide dating (TCND), have achieved an impressive progress in both laboratory precision and regional calibration models during the past few decades. It is now possible to apply precise TCND even to young landforms like Late Holocene moraines, a task seemed hardly achievable just about 15 years ago. An increasing number of studies provide very precise TCND ages for boulders from Late Holocene moraines enabling related reconstruction of glacier chronologies and the interpretation of these glacial landforms in a palaeoclimatological context. These studies may also solve previous controversies about different ages assigned to moraines obtained by different dating techniques, for example relative-age dating techniques or techniques combining relative-age dating with few fixed points derived from numerical age dating. There are a few cases, for example Mueller Glacier and nearby long debris-covered valley glacier in Aoraki/Mt.Cook National Park (Southern Alps, New Zealand), where the apparent "supremacy" of TCND-ages seem to overrule glacial geomorphological principles. Enabled by a comparatively high number of individual boulders precisely dated by TCND, moraine ridges on those glacier forelands have been primarily clustered on basis of these boulder ages rather than on their corresponding morphological position. To the extreme, segments of a particular moraine complex morphologically and sedimentologically proven to be formed during one event have become split and classified as two separate "moraines" on different parts of the glacier foreland. One ledge of another moraine complex contains 2 TCND-sampled boulders apparently representing two separate "moraines"-clusters of an age difference in the order of 1,500 years. Although recently criticism has been raised regarding the non-contested application of the arithmetic mean for calculation of TCND-ages for individual moraines, this

  2. Geomorphology of Goa and Goa Coast. A review

    Digital Repository Service at National Institute of Oceanography (India)

    Wagle, B.G.

    This review on the geomorphology of Goa and the Goa coast included studies on the interpretation of LANDSAT images, aerial photographs and extensive field work. Physiographically the region can be broadly classified into: 1) the coastal tract; 2...

  3. Geomorphologic map and derived geomorphological evolution model of the Ampato volcanic complex (Southern Peru). (United States)

    Alcalá, J.; Zamorano, J. J.; Palacios, D.


    In this work we present the evolution of the Ampato volcanic complex (15°24´-15° 51´S, 73°W; 6.288 m asl) from a geomorphological perspective based on the analysis of landforms, both volcanic and derived from cold processes such as moraines and rock glaciers. In order to do so, a detailed 1:20.000 scale geomorphological map was elaborated by integrating the following techniques: the interpretation of the 1:35.000 scale aerial photographs (Instituto Geográfico Nacional de Perú, 1956) and the analysis of satellite images (Mrsid; NASA, 2000). The cartography was corrected through field work campaigns. A geomorphological cross-section traversing the map from North to South was elaborated in order facilitate the interpretation of the landforms. From the thorough analysis of the landforms represented in the geomorphological map and their relative position we have identified six main volcanic phases, mainly constructive but also, to a lesser extent, destructive (related with a Sant. Helens eruption), interspersed by five large glacial phases. From the three andesitic stratovolcanoes that form the complex (HualcaHualca, Sabancaya and Ampato) we suggest that the oldest of them is HualcaHualca representing the first step of the process over which the other units were placed. The most recent phase corresponds to the main cone of Sabancaya and its sets of domes and large lavas flows. Also we have detected a number of well-preserved vents on the Southern slope of volcano HualcaHualca close to the 1955 glacier tongues. Their presence is an evidence of recent volcanic activity in a volcano considered extinct. The glacial activity has been very active during the Quaternary on the Ampato Complex. The most ancient glacial phase is linked to the Last Glacial Maximum of the Pleistocene. During this event, the paleoglaciers descended down to 3650 m asl and builted moraines of 25- 30 m height. The most recent advance is related to the global event known as Little Ice Age (LIA

  4. Being an expert witness in geomorphology (United States)

    Keller, Edward A.


    Gathering your own data and coming to your own conclusion through scientific research and discovery is the most important principle to remember when being an expert witness in geomorphology. You can only be questioned in deposition and trial in your area of expertise. You are qualified as an expert by education, knowledge, and experience. You will have absolutely nothing to fear from cross-examination if you are prepared and confident about your work. Being an expert witness requires good communication skills. When you make a presentation, speak clearly and avoid jargon, especially when addressing a jury. Keep in mind that when you take on a case that may eventually go to court as a lawsuit, the entire process, with appeals and so forth, can take several years. Therefore, being an expert may become a long-term commitment of your time and energy. You may be hired by either side in a dispute, but your job is the same - determine the scientific basis of the case and explain your scientific reasoning to the lawyers, the judge, and the jury. Your work, including pre-trial investigations, often determines what the case will be based on. The use of science in the discovery part of an investigation is demonstrated from a California case involving the Ventura River, where building of a flood control levee restricted flow to a narrower channel, increasing unit stream power as well as potential for bank erosion and landsliding.


    Directory of Open Access Journals (Sweden)

    Florina Grecu


    Full Text Available The Hârtibaciu Tableland (4,000 sqkm, 80 km long an d 50 km wide is a distinct subunit of the Transylvanian Tableland. Sarmatian and Panno nian sedimentary formations represent an alternation of impermeable marly-claey strata and p ermeable strata of sands, loosely cemented sandstones and conglomerates with a monocline struct ure, locally disturbed by folds of a general E-W or N-S orientation. The grade of fragmentation in point of energy and density of slopes, geodeclivity, climate and edaphic conditions, as wel l as human intervention reflect in the diversity of present-day geomorphic processes. A hierarchy of geomorphic risk classes – high, moderate and low, has been established based on slope dynamic s, as the outcome of a combination of main criteria (type of dominant process, volume of mater ial dislodged by erosion, landslides and human activity. Transition from one class to anoth er has rather a limited value for predicting process evolution. The normal evolution of natural processes in agreement with slope balance at a certain moment, tends to stabilise the terrain. Whenever ex treme natural phenomena cause imbalances on slope, bringing about changes of relief configuration and producing material damage or casualties, geomorphological hazards develop.

  6. Vanishing point: Scale independence in geomorphological hierarchies (United States)

    Phillips, Jonathan D.


    Scale linkage problems in geosciences are often associated with a hierarchy of components. Both dynamical systems perspectives and intuition suggest that processes or relationships operating at fundamentally different scales are independent with respect to influences on system dynamics. But how far apart is "fundamentally different"-that is, what is the "vanishing point" at which scales are no longer interdependent? And how do we reconcile that with the idea (again, supported by both theory and intuition) that we can work our way along scale hierarchies from microscale to planetary (and vice-versa)? Graph and network theory are employed here to address these questions. Analysis of two archetypal hierarchical networks shows low algebraic connectivity, indicating low levels of inferential synchronization. This explains the apparent paradox between scale independence and hierarchical linkages. Incorporating more hierarchical levels results in an increase in complexity or entropy of the network as a whole, but at a nonlinear rate. Complexity increases as a power α of the number of levels in the hierarchy, with α < 1 and usually ≤ 0.6. However, algebraic connectivity decreases at a more rapid rate. Thus, the ability to infer one part of the hierarchical network from other level decays rapidly as more levels are added. Relatedness among system components decreases with differences in scale or resolution, analogous to distance decay in the spatial domain. These findings suggest a strategy of identifying and focusing on the most important or interesting scale levels, rather than attempting to identify the smallest or largest scale levels and work top-down or bottom-up from there. Examples are given from soil geomorphology and karst flow networks.

  7. The Geomorphological Effects of Old Routes (United States)

    Martinek, Jan; Bíl, Michal


    The communication network in rural areas in the historical Czech Lands predominantly consisted of unpaved routes prior to the eighteenth century. Certain parts of the network were transformed gradually into the current roads and are now being used by motor traffic. The majority of the old routes form, however, an abandoned network the remnants of which (abandoned during the Middle Ages or even earlier) are currently being discovered. Certain segments of used unpaved routes were, over the course of time, transformed into holloways (sunken lanes) and consequently also abandoned. The degree of incision of the holloway into the soil was determined by local geological conditions. Routes, which were abandoned due to more difficult transport in holloways, have distinct linear forms and can often be found as a grouping of parallel holloways. This indicates that these routes were frequently used or localized on low-resistant ground. Analyses of the precise digital elevation models, derived from LIDAR data, can reveal the distinct pattern of an old route network quite often interacting with other geomorphological phenomena (e.g., landslides, streams) or old human constructions (e.g., fortified settlements). We will present several cases where old paths interacted with landslides. These facts can consequently be used for dating the purposes of both the landslides and the old path sections. General erosion impacts, the degree of incision of the old transportation lines, can also be quantified through analyses of digital elevation models taking into consideration the former and new, incised, surface. We will demonstrate the methodology used for these analyses and the preliminary results.

  8. The educational value of the history of geomorphology (United States)

    Sack, Dorothy


    The history of geomorphology can be a valuable tool for educating students of geomorphology. The largest and most available record of what geomorphologists thought and did in the past is their original published work. Also available are some fine papers on the history of geomorphology that review and analyze primary sources and past events in the discipline in order to generalize, explain trends, and reveal historical associations. Interest in the history of the discipline varies widely, of course, among geomorphologists. Nevertheless, several educational benefits, in addition to explaining the academic affiliation of geomorphology with two separate disciplines, can be derived from incorporating the history of geomorphology into university-level geomorphology courses. History is a popular subject,and presenting some geomorphic concepts using a historical approach can help to maintain or stimulate student interest. Because of the tendency for older literature to contain more qualitative description and methodological detail than more recent literature, undergraduate students may comprehend some concepts better from older papers. By reading the original literature, students determine for themselves what previous practitioners accomplished, rather than relying solely on the interpretations of others. Reading original literature also helps students realize that older does not mean less intelligent, and that like the critical reading of recent geomorphic literature, the critical reading of historic geomorphic papers can provide a wealth of new research ideas. A thematic set of the historic literature can be used to demonstrate to students the scientific method, the origin, testing, and evolution of hypotheses, how explanations develop in this field, and that science proceeds through individuals working in a sociological context. Including history of geomorphology in the curriculum helps to place contemporary research in the perspective of the past as well as the

  9. Possibilities for a valorisation of geomorphologic research deliverables (United States)

    Geilhausen, M.; Götz, J.; Otto, J.-C.; Schrott, L.


    Many geomorphological studies focus on fundamental research questions in large parts, although there are lots of applied fields like landslide hazard assessment or water framework directive. As fundamental research is a common property, their outcomes should be more "open" and accessible to the public. This means that scientists have to find new ways presenting their results and outcomes besides publishing in scientific journals. This paper shows possibilities for a valorisation of geomorphologic research deliverables using print as well as digital media. Geotrails explain remarkable and exciting landscape features using information boards and become more and more popular and important for tourism in many parts of the world. With the growing interest in environmental change and outdoor activities, print media like field guides reach an increasing number of people. Field guides and Geotrails can be coupled in order to arise awareness about geomorphological landforms and to deliver more specific information on the site beyond the information given on the boards in the field. As field guides are designed for the general public they can be used for educational purposes as well. Today, this information can also be found in the internet offering virtual trips through landscapes using dynamic maps. Here, server side GIS technologies (WebGIS) using standardised interfaces provide new possibilities to show geomorphic data to the public and to share them with the scientific community. Furthermore, data formats like XML or KML are powerful tools for data exchange and can be used in interactive data viewers like Google Earth. We will present the Geotrail "Geomorphologischer Lehrpfad am Fuße der Zugspitze. Das Reintal - Eine Wanderung durch Raum und Zeit" (Bavarian Alps, Germany). Additionally, three geomorphologic WebGIS applications (Geomorphologic map Turtmanntal, Permafrostmap of Austria, Geomorphologic maps of Germany) will exemplify how geomorphologic information and


    Directory of Open Access Journals (Sweden)

    Ekaterina V. Lebedeva


    Full Text Available Geological-and-tectonic and physiographical features of the South American Pacific coast caused high intensity of morpholitogenesis including disaster-like way of some geomorphologic processes. Their complex, interaction, and intensity of conductive factors increase the risk of disaster. The Andean terrain morphology and rock lithology, precipitation type, and vegetation status are the main drivers that influence the character and high potential intensity of the geomorphologic processes. The enormous hydrometeorological events, frequent seismic shocks, volcanic eruptions, and human impact cause disasters development. A schematic map of disaster and hazardous processes for the Central sector of Andes was compiled. 16 areas with different spectra of the dominant catastrophic processes were identified. The South American Andes extension allows drawing out principles of geomorphologic disasters of these continental marginal mountains in various natural zones - from temporal to subequatorial latitudes, which are characterized by the individual unique heat-moisture rate, which governs both typical and extreme geomorphologic processes. An important feature of the study area is the asymmetric distribution of geomorphologic processes within coastal and inland slopes of the mountain system, as well as latitudinal zoning of this distribution.

  11. Structure and contents of a new geomorphological GIS database linked to a geomorphological map — With an example from Liden, central Sweden (United States)

    Gustavsson, Marcus; Seijmonsbergen, Arie C.; Kolstrup, Else


    This paper presents the structure and contents of a standardised geomorphological GIS database that stores comprehensive scientific geomorphological data and constitutes the basis for processing and extracting spatial thematic data. The geodatabase contains spatial information on morphography/morphometry, hydrography, lithology, genesis, processes and age. A unique characteristic of the GIS geodatabase is that it is constructed in parallel with a new comprehensive geomorphological mapping system designed with GIS applications in mind. This close coupling enables easy digitalisation of the information from the geomorphological map into the GIS database for use in both scientific and practical applications. The selected platform, in which the geomorphological vector, raster and tabular data are stored, is the ESRI Personal geodatabase. Additional data such as an image of the original geomorphological map, DEMs or aerial orthographic images are also included in the database. The structure of the geomorphological database presented in this paper is exemplified for a study site around Liden, central Sweden.

  12. Geomorphological Approach for Regional Zoning In The Merapi Volcanic Area

    Directory of Open Access Journals (Sweden)

    Langgeng Wahyu Santosa


    Full Text Available Geomorphologial approach can be used as the basic for identifying and analyzing the natural resources potentials, especially in volcanic landscape. Based on its geomorphology, Merapi volcanic landscape can be divided into 5 morphological units, i.e.: volcanic cone, volcanic slope, volcanic foot, volcanic foot plain, and fluvio-volcanic plain. Each of these morphological units has specific characteristic and natural resources potential. Based on the condition of geomorphology, the regional zoning can be compiled to support the land use planning and to maintain the conservation of environmental function in the Merapi Volcanic area.

  13. Prediction of downstream geomorphological changes after dam construction: A stream power approach

    DEFF Research Database (Denmark)

    Brandt, Anders


    physical geography, hydrology, reservoirs, sediment transport, erosion, sedimentation, fluvial geomorphology, dams, river channel geometry......physical geography, hydrology, reservoirs, sediment transport, erosion, sedimentation, fluvial geomorphology, dams, river channel geometry...

  14. Semi-automated identification and extraction of geomorphological features using digital elevation data

    NARCIS (Netherlands)

    Seijmonsbergen, A.C.; Hengl, T.; Anders, N.S.; Smith, M.J.; Paron, P.; Griffiths, J.S.


    Geomorphological maps that are automatically extracted from digital elevation data are gradually replacing classical geomorphological maps. Commonly, digital mapping projects are based upon statistical techniques, object-based protocols or both. In addition to digital elevation data, expert knowledg

  15. Delineating riparian zones for entire river networks using geomorphological criteria

    Directory of Open Access Journals (Sweden)

    D. Fernández


    Full Text Available Riparian zone delineation is a central issue for riparian and river ecosystem management, however, criteria used to delineate them are still under debate. The area inundated by a 50-yr flood has been indicated as an optimal hydrological descriptor for riparian areas. This detailed hydrological information is, however, not usually available for entire river corridors, and is only available for populated areas at risk of flooding. One of the requirements for catchment planning is to establish the most appropriate location of zones to conserve or restore riparian buffer strips for whole river networks. This issue could be solved by using geomorphological criteria extracted from Digital Elevation Models. In this work we have explored the adjustment of surfaces developed under two different geomorphological criteria with respect to the flooded area covered by the 50-yr flood, in an attempt to rapidly delineate hydrologically-meaningful riparian zones for entire river networks. The first geomorphological criterion is based on the surface that intersects valley walls at a given number of bankfull depths above the channel (BFDAC, while the second is based on the surface defined by a~threshold value indicating the relative cost of moving from the stream up to the valley, accounting for slope and elevation change (path distance. As the relationship between local geomorphology and 50-yr flood has been suggested to be river-type dependant, we have performed our analyses distinguishing between three river types corresponding with three valley morphologies: open, shallow vee and deep vee valleys (in increasing degree of valley constrainment. Adjustment between the surfaces derived from geomorphological and hydrological criteria has been evaluated using two different methods: one based on exceeding areas (minimum exceeding score and the other on the similarity among total area values. Both methods have pointed out the same surfaces when looking for those that

  16. Fluvial geomorphology: where do we go from here? (United States)

    Smith, Derald G.


    The evolution of geomorphology and in particular, fluvial geomorphology, is at a crossroads. Currently, the discipline is dismally organized, without focus or direction, and is practised by individualists who rarely collaborate in numbers significant enough to generate major research initiatives. If the discipline is to mature and to prosper, we must make some very difficult decisions that will require major changes in our ways of thinking and operating. Either the field stays in its current operational mode and becomes a backwater science, or it moves forward and adopts the ways of the more competitive sectors of the earth and biosciences. For the discipline to evolve, fluvial geomorphologists must first organize an association within North America or at the international level. The 3rd International Geomorphology Conference may be a start, but within that organization we must develop our own divisional and/or regional organizations. Within the Quaternary geology/geomorphology divisions of the Geological Socieity of America (GSA), Association of American Geographers (AAG), American Geophysical Union (AGU) and British Geomorphology Research Group (BGRG) the voice of fluvial geomorphology is lost in a sea of diverse and competitive interests, though there is reason for hope resulting from some recent initiatives. In Canada, we have no national geomorphology organization per se; our closest organization is Canqua (Canadian Quaternary Association). Next, fluvial researchers must collaborate, by whatever means, to develop "scientific critical mass" in order to generate ideas and long-range goals of modest and major scientific importance. These projects will help secure major research funding without which, research opportunities will diminish and initiating major new research will become nearly impossible. Currently, we are being surpassed by the glaciologists, remote sensors, ecologists, oceanographers, climatologists-atmospheric researchers and some Quaternary

  17. Geoconservation mapping using digital geomorphological maps in Vorarlberg, Austria (United States)

    Seijmonsbergen, A. C.; De Jong, M. G. G.; de Graaff, L. W. S.; Anders, N. S.


    Geomorphological inventories are being made in the State of Vorarlberg (Austria) since the mid-1950s by the University of Amsterdam. Starting as an academic training fieldwork for undergraduate geomorphology students, PhD students and staff members soon recognized the research potential of the unique alpine landscape. In particular, landforms and deposits of the ice-marginal environment and pollen records preserved in peat provide valuable proxies for climate reconstruction and give detailed insight in the former growth and decay of the Rhine glacier network and of local glaciers, and assist in reconstructing landscape development in general. A project was started in 2007 to prepare community wide inventory maps of potential geoconservation areas, based on digital geomorphological mapping in a Geographical Information System (GIS). A stepwise protocol was designed for the identification of potential geoconservation areas in the landscape, comprising: 1. Preparing digital geomorphological maps, using a morphogenetic classification scheme 2. Assigning values for selected geoconservation assessment criteria to types of geomorphological features 3. Ranking the criteria assessment values into three categories of potential geoconservation value, and 4. Storing, visualizing and describing the geoconservation data. Four major traits are used in the weighting and ranking protocol (steps 2 and 3): scientific relevance, frequency of occurrence, disturbance, and environmental vulnerability. The process of assigning values and of ranking the landforms and deposits has been automated in GIS. For the evaluation of disturbance we use digital infrastructure layers in GIS which can be intersected with the potential geoconservation areas to determine the level of disturbance. The proposed method is demonstrated for the municipality of Lech, a well-known winter skiing resort. To illustrate the loss of high-rank potential geoconservation areas due to human influence over the last 50

  18. Highlighting landslides and other geomorphological features using sediment connectivity maps (United States)

    Bossi, Giulia; Crema, Stefano; Cavalli, Marco; Marcato, Gianluca; Pasuto, Alessandro


    Landslide identification is usually made through interpreting geomorphological features in the field or with remote sensing imagery. In recent years, airborne laser scanning (LiDAR) has enhanced the potentiality of geomorphological investigations by providing a detailed and diffuse representation of the land surface. The development of algorithms for geomorphological analysis based on LiDAR derived high-resolution Digital Terrain Models (DTMs) is increasing. Among them, the sediment connectivity index (IC) has been used to quantify sediment dynamics in alpine catchments. In this work, maps of the sediment connectivity index are used for detecting geomorphological features and processes not exclusively related to water-laden processes or debris flows. The test area is located in the upper Passer Valley in South Tyrol (Italy). Here a 4 km2 Deep-seated Gravitational Slope Deformation (DGSD) with several secondary phenomena has been studied for years. The connectivity index was applied to a well-known study area in order to evaluate its effectiveness as an interpretative layer to assist geomorphological analysis. Results were cross checked with evidence previously identified by means of in situ investigations, photointerpretation and monitoring data. IC was applied to a 2.5 m LiDAR derived DTM using two different scenarios in order to test their effectiveness: i) IC derived on the hydrologically correct DTM; ii) IC derived on the original DTM. In the resulting maps a cluster of low-connectivity areas appears as the deformation of the DGSD induce a convexity in the central part of the phenomenon. The double crests, product of the sagging of the landslide, are extremely evident since in those areas the flow directions diverge from the general drainage pattern, which is directed towards the valley river. In the crown area a rock-slab that shows clear evidence of incumbent detachment is clearly highlighted since the maps emphasize the presence of traction trenches and

  19. Toward a new system approach of complexity in geomorphology (United States)

    Masson, E.


    Since three decades the conceptual vision of catchment and fluvial geomorphology is strongly based on the "fluvial system" (S. A. Schumm, 1977) and the "river continuum system" (R. L. Vannote et al., 1980) concepts that can be embedded in a classical physical "four dimensions system" (C. Amoros and G.-E. Petts, 1993). Catchment and network properties, sediment and water budgets and their time-space variations are playing a major role in this geomorpho-ecological approach of hydro-geomorphosystems in which human impacts are often considered as negative externalities. The European Water Framework Directive (i.e. WFD, Directive 2000/60/EC) and its objective of good environmental status is addressing the question of fluvial/catchment/landscape geomorphology and its integration into IWRM in such a sustainable way that deeply brings back society and social sciences into the water system analysis. The DPSIR methodology can be seen as an attempt to cope with the analysis of unsustainable consequences of society's water-sediment-landscape uses, environmental pressures and their consequences on complex fluvial dynamics. Although more and more scientific fields are engaged in this WFD objective there's still a lack of a global theory that could integrate geomorphology into the multi-disciplinary brainstorming discussion about sustainable use of water resources. Our proposition is to promote and discuss a trans-disciplinary approach of catchments and fluvial networks in which concepts can be broadly shared across scientific communities. The objective is to define a framework for thinking and analyzing geomorphological issues within a whole "Environmental and Social System" (i.e. ESS, E. Masson 2010) with a common set of concepts and "meta-concepts" that could be declined and adapted in any scientific field for any purpose connected with geomorphology. We assume that geomorphological research can benefit from a six dynamic dimensions system approach based on structures

  20. Geomorphological hazard and tourist vulnerability along Portofino Park trails (Italy

    Directory of Open Access Journals (Sweden)

    P. Brandolini


    Full Text Available The many trails existing in the coastal area of Portofino Promontory are used by tourists for trekking or as pathways to small villages and beaches. The aim of this paper is to define geomorphological hazard and tourist vulnerability in this area, within the framework of the management and planning of hiking activities in Portofino Natural Park. In particular, processes triggered by gravity, running waters and wave motion, affecting the slopes and the cliff, are considered. The typology of the trails and trail maintenance are also taken into account in relation to weather conditions that can make the excursion routes dangerous for tourists. In conclusion, an operative model is applied for the definition of possible risk scenarios. This model is founded on an inventory and the quantification of geomorphological hazards and tourist vulnerability, in comparison with trail rescue data. The model can be applied to other environments and tourist areas.


    Directory of Open Access Journals (Sweden)



    Full Text Available Soils vulnerability of the Catchment Almas geomorphologic processes. Almas Basin, signed lower lithologic Miocene soils deposits, shows six classes: Cernisols, Cambisols, Luvisols, Hydrosols, Pelisols, Protosols (after SRTS, 2003. The largest share is attributed to Luvisols class (60%, followed by undeveloped soil represented by Protosols and Antrisols (15%, followed by the remaining classes with lower weights: Cambisols (13%, Cernisols (7%, Pelisols (4%, Hydrosols (1%. Contemporary geomorphological processes (surface and deep erosion, mass movements change agricultural areas and forest ratio or flow out of economic network tens of hectares annually. Soil vulnerability to the manifestation of these processes is expressed by disturbing soil horizons, coastal springs appearance and growth of the adjoining excess moisture, soil sealing productive by dropping or by alienation.

  2. Geomorphological hazard and tourist vulnerability along Portofino Park trails (Italy) (United States)

    Brandolini, P.; Faccini, F.; Piccazzo, M.


    The many trails existing in the coastal area of Portofino Promontory are used by tourists for trekking or as pathways to small villages and beaches. The aim of this paper is to define geomorphological hazard and tourist vulnerability in this area, within the framework of the management and planning of hiking activities in Portofino Natural Park. In particular, processes triggered by gravity, running waters and wave motion, affecting the slopes and the cliff, are considered. The typology of the trails and trail maintenance are also taken into account in relation to weather conditions that can make the excursion routes dangerous for tourists. In conclusion, an operative model is applied for the definition of possible risk scenarios. This model is founded on an inventory and the quantification of geomorphological hazards and tourist vulnerability, in comparison with trail rescue data. The model can be applied to other environments and tourist areas.

  3. Geomorphological hazard and tourist vulnerability along Portofino Park trails (Italy)


    Brandolini, P.; F. Faccini; Piccazzo, M.


    International audience; The many trails existing in the coastal area of Portofino Promontory are used by tourists for trekking or as pathways to small villages and beaches. The aim of this paper is to define geomorphological hazard and tourist vulnerability in this area, within the framework of the management and planning of hiking activities in Portofino Natural Park. In particular, processes triggered by gravity, running waters and wave motion, affecting the slopes and the cliff, are consi...

  4. Sea floor engineering geomorphology: recent achievements and future directions (United States)

    Prior, David B.; Hooper, James R.


    New mapping technology is providing perspectives of the sea floor "as if there were no ocean", revealing that ocean floors exhibit a wide variety of relief, sediment properties, and active geologic processes such as erosion, faulting, fluid expulsion, and landslides. The development of coastal and offshore resources, such as oil and gas and minerals, involves sea floor engineering in remote, complex, and sometimes hazardous environments. Optimum engineering design and construction practice require detailed surveys of sea floor geomorphology, geologic conditions on the sea bed and to various depths beneath it, combined with geotechnical properties of the sediments and oceanographic information. Integrated site survey models attempt to predict conditions and process frequencies and magnitudes relevant to the engineering design lifetimes of sea floor installations, such as cables, pipelines, production platforms, as well as supporting coastal infrastructure such as jetties, wharves, bridges and harbors. Recent use of deep water areas for oil and gas production, pipelines, and cable routes are also showing that the "world's greatest slopes", beyond the continental shelves contain exciting, exotic, and enigmatic geomorphological features and processes. Safe and cost-effective engineering use of these regions depends upon exciting new technical and conceptual advances for understanding sea floor geomorphology — a task which has barely begun.

  5. Theory of Geoinformatic Mapping of Erosive Geomorphological System

    Directory of Open Access Journals (Sweden)

    Rulev A.S.


    Full Text Available The geoinformatic mapping of erosion geomorphologic systems is based on both traditional methods of cartographic representation of information and specific opportunities of computer mapping complexes, including those for analytical processing of data of different types. The study of the characteristics of the erosion geomorphological systems is carried out with the use of aerial and satellite imagery and is based on the results of their geomorphological, geobotanical, soil reclamation, erosion and other surveys. Spatially distributed input data of landscape model should be set as raster electronic maps that characterize relief, soil cover, type of agriculture, vegetation on the catchment area, as well as, morphometry and hydraulic resistance of the channel and floodplain, and also as a set of the attributes describing their characteristics. The use of digital model of relief (DMR while geoinformatic mapping provides the determination of both planning characteristics of the relief and profile ones, including the values of slope angles, inclination, expositions, slopes configuration, etc. As the result of the modelling, the digital maps of flow, outwash and accumulation, and table data defining the process of flow, outwash and water turbidity, as well as, their final values with the use of large-scale topographic and soil maps, and space imaging of high resolution, are developed.

  6. Geomorphology of ice stream beds: recent progress and future challenges (United States)

    Stokes, Chris R.


    Ice sheets lose mass primarily by melting and discharge via rapidly-flowing ice streams. Surface and basal melting (e.g. of ice shelves) are closely linked to atmospheric and oceanic conditions, but the mechanisms that drive changes in ice stream discharge are more complex; and are influenced by conditions at their bed which can sustain, enhance or inhibit their motion. Although explicit comparisons are rare, the ice-bed interface is similar to the 'boundary layer' in fluvial and aeolian environments, where shear stresses (both basal and lateral in the case of ice streams) oppose the flow of the overlying medium. The analogy extends further because processes within the boundary layer create a distinctive geomorphology (and roughness) that is characterised by subglacial bedforms that resemble features in fluvial and aeolian environments. Their creation results from erosion, transport and deposition of sediment which is poorly constrained, but which is intimately linked to the mechanisms through which ice streams are able to flow rapidly. The study of ice stream geomorphology is, therefore, critical to our understanding of their dynamics. Despite difficulty in observing the subglacial environment of active ice streams, our understanding of their geomorphology has grown rapidly in the last three decades, from almost complete ignorance to a detailed knowledge of their geomorphological products. This has been brought about by two main approaches: (i) geophysical investigation of modern (active) ice streams, and (ii) sedimentological and geomorphological investigation of palaeo-ice stream beds. The aim of this paper is to review progress in these two areas, highlight the key questions that remain, and discuss the opportunities that are likely to arise that will enable them to be addressed. It is clear that whilst these two main approaches have led to important advances, they have often been viewed as separate sub-disciplines, with minimal cross-pollination of ideas and

  7. Directions in Geoheritage Studies: Suggestions from the Italian Geomorphological Community (United States)

    Panizza, Valeria


    More and more attention has been focused on geological and geomorphological heritage in the past years, leading to several researches in the framework of conservation projects, both at administrative and at scientific level, involving national and international research groups whose purposes are the promotion of Earth Sciences knowledge and the conservation of geological heritage. This paper presents an overview of research and conservation projects in Italy, mainly focused on the geomorphological heritage. Members of the AIGEO Working Group on geomorphosites and cultural landscape analyzed the historical development, methodological issues and main results of these research projects in order to identify possible innovation lines to improve the awareness and knowledge on geodiversity and geoheritage by a wide public, including education, tourism and conservation sectors. In Italy numerous projects of research have been realized with the main aim of geomorphosites inventory and the proposal of assessment methodologies, and so to the improvement and to the analysis of risks and impacts related to their fruition. At an international level, many Italian researchers have also been involved in studies carried out in the Working Group "Geomorphological sites" of the International Association of Geomorphologists (IAG). At a national level several research lines are under development, offering different responses to methodological issues within the general topic of geodiversity and geoheritage: Geosites inventories and assessment activities are performed with powerful digital techniques and new reference models: among these, the investigation on the ecologic support role for increasing geomorphosites global value and the elaboration of quantitative assessment methods of the scientific quality of Geomorphosites, carried out specifically for territorial planning. Improvements in field data collection and visual representation of landforms lead to new findings in

  8. Detailed geomorphological map sheet Bela Palanka at scale 1:100,000

    Directory of Open Access Journals (Sweden)

    Menković Ljubomir


    Full Text Available The Geomorphological Map Sheet Bela Palanka is a graphical representation of landforms in the area covered by the Topographical Map Sheet Bela Palanka at scale 1:100,000. The map is published in 2008 by the Serbian Academy of Sciences and Arts (SASA and the SASA Geodynamics Board. It is the first detailed geomorphological map edited in Serbia. This paper presents the methods used in preparing the geomorphological map, the contents and the mode of data presentation, geologic structure, genetic types of landforms and the subtypes, and the geomorphological history since the Neogene.

  9. Short-term geomorphological evolution of proglacial systems (United States)

    Carrivick, Jonathan L.; Heckmann, Tobias


    Proglacial systems are amongst the most rapidly changing landscapes on Earth, as glacier mass loss, permafrost degradation and more episodes of intense rainfall progress with climate change. This review addresses the urgent need to quantitatively define proglacial systems not only in terms of spatial extent but also in terms of functional processes. It firstly provides a critical appraisal of prevailing conceptual models of proglacial systems, and uses this to justify compiling data on rates of landform change in terms of planform, horizontal motion, elevation changes and sediment budgets. These data permit us to produce novel summary conceptual diagrams that consider proglacial landscape evolution in terms of a balance of longitudinal and lateral water and sediment fluxes. Throughout, we give examples of newly emerging datasets and data processing methods because these have the potential to assist with the issues of: (i) a lack of knowledge of proglacial systems within high-mountain, arctic and polar regions, (ii) considerable inter- and intra-catchment variability in the geomorphology and functioning of proglacial systems, (iii) problems with the magnitude of short-term geomorphological changes being at the threshold of detection, (iv) separating short-term variability from longer-term trends, and (v) of the representativeness of plot-scale field measurements for regionalisation and for upscaling. We consider that understanding of future climate change effects on proglacial systems requires holistic process-based modelling to explicitly consider feedbacks and linkages, especially between hillslope and valley-floor components. Such modelling must be informed by a new generation of repeated distributed topographic surveys to detect and quantify short-term geomorphological changes.

  10. Stream piracy in the Black Hills: A geomorphology lab exercise (United States)

    Zaprowski, B.J.; Evenson, E.B.; Epstein, J.B.


    The Black Hills of South Dakota exhibits many fine examples of stream piracy that are very suitable for teaching geomorphology lab exercises. This lab goes beyond standard topographic map interpretation by using geologic maps, well logs, gravel provenance and other types of data to teach students about stream piracy. Using a step-by-step method in which the lab exercises ramp up in difficulty, students hone their skills in deductive reasoning and data assimilation. The first exercises deal with the identification of stream piracy at a variety of spatial scales and the lab culminates with an exercise on landscape evolution and drainage rearrangement.


    Directory of Open Access Journals (Sweden)

    Belkacem BOUMARAF


    Full Text Available This study is a first in a Saharan region. Following a collaboration between soil scientists and geomorphologists a geomorphological mapping was realized. This work aims to understand the evolution of Saharan soils .The result we obtained demonstrated the presence of five geomorphological soil level. Each level and defined as soil with special chemical, physical and genetic characteristic.

  12. Geomorphological change detection using object-based feature extraction from multi-temporal LIDAR data

    NARCIS (Netherlands)

    Seijmonsbergen, A.C.; Anders, N.S.; Bouten, W.; Feitosa, R.Q.; da Costa, G.A.O.P.; de Almeida, C.M.; Fonseca, L.M.G.; Kux, H.J.H.


    Multi-temporal LiDAR DTMs are used for the development and testing of a method for geomorphological change analysis in western Austria. Our test area is located on a mountain slope in the Gargellen Valley in western Austria. Six geomorphological features were mapped by using stratified Object-Based

  13. Geomorphological inventory of rock landforms on Mt. Kamenec in the Novohradské hory Mts. (the Czech Republic)


    Rypl, J.; Kirchner, K. (Karel); Dvořáčková, S.


    This paper deals with the cryogenic granite landforms on Mt. Kamenec (1 072 m a.s.l.) located in the Novohradské hory Mts (southern Bohemia). Detailed geomorphological distribution and description of cryogenic landforms were obtained with using detailed geomorphological mapping. On the basis of field research the geomorphological map of the study locality was elaborated. Using of geomorphological inventory enabled the evaluation of landforms in study area and providing of proposal for nature ...

  14. Geomorphological mapping of the Comet 67P/Churyumov-Gerasimenko (United States)

    Giacomini, L.; Massironi, M.; Thomas, N.; Pajola, M.; Cremonese, G.; La Forgia, F.; Ferri, F.; Lazzarin, M.; Barbieri, C.; Bettini, I.; Magrin, S.; Marzari, F.; Naletto, G.; Sierks, H.; Rosetta OSIRIS Team

    OSIRIS, the Scientific Imaging System for Rosetta mission \\citep{keller07} has been acquiring images of the nucleus of the comet 67P/Churyumov-Gerasimenko since Aug 2014 with a resolution that allows a detailed analysis of its surface. Indeed, data reveal a complex surface morphology that is likely the expression of different processes affecting the cometary nucleus \\citep{thomas15}. In order to characterize these different morphologies and better understand their distribution we performed a geomorphological mapping of the illuminated surface of 67P. For this purpose we used NAC images acquired on August 5-8 with a spatial resolution ranging from 1.5 and 2.4 m/pixel.

  15. sUAS and their application in observing geomorphological processes (United States)

    Gallik, Jozef; Bolešová, Lenka


    Methodologies and procedures in processing gained data vary based on possibilities and needs of scientific projects. This paper should help to get a general overview in the choice of small unmanned aircraft systems (sUAS - commonly known as drones) for scientific purposes, namely remote sensing of geomorphologic processes such as soil degradation in high mountainous areas that are hard to access and have unfavourable weather conditions. All high mountain areas in European countries are legislatively protected, and so various permissions and observation of strict procedures are needed in order to not have a negative influence on the environment. Nowadays, several types of UAS exist that could effectively help us in such protection, as well as in full-fledged utilization when answering scientific questions about the alpine lake genesis. We demonstrate it here with selected examples of our photo documentation.

  16. Rainfall event profiles: importance in ecohydrology, geomorphology, and soil management (United States)

    Dunkerley, D.


    The importance of the temporal structure of rainfall events is widely, but not universally, recognised. In agricultural research, the role of event structure has been quite well explored (e.g. in relation to leachates from manure, or in agrochemical washoff). However, in dryland hydrology, and in soil erosion research, much less attention has been paid to the role of aspects such as intensity variations or rain intermittency. Moreover, changes in rainfall event profiles form a little-explored aspect of ongoing climatic change, but one that may have great significance in ecohydrology and in geomorphology. The importance of rain event structure is clearly demonstrated from rainfall simulation experiments on dryland soils in arid NSW Australia. A series of small plot experiments using drop-forming rainfall simulation was established in order to explore the effects of varying event profiles on infiltration and the generation of runoff. Experiments all had the same rain event duration, the same mean rain rate, and the same total event depth. However, event profile, including peak intensity, and intermittency, were varied by using computer-controlled pumps. The rain rates and event profiles were designed to mimic the character of natural rainfall events in the study area. Results show that events with uniform rainfall rates, as widely used in rainfall simulations in soil erosion research and in hydrology, yield the highest apparent soil infiltrability and the least runoff volume. Events with peak intensity late in the event, when soils are already wet, yield the lowest apparent infiltrability and the highest runoff volume, as well as the highest runoff intensity. These results need to be confirmed for other soil types, but suggest that event profile is an important determinant of soil hydraulic behaviour that warrants increased attention in many fields, including ecohydrology, geomorphology, and soil management.

  17. The geomorphology of a glaciated continental shelf, Western Scotland, UK (United States)

    Howe, John; Dove, Dayton; Bradwell, Tom


    We present recently collected swath bathymetry and legacy seismic data from two regions of the north-west UK continental shelf: the Sea of the Hebrides; and the Firth of Lorn, western Scotland. Both regions have experienced extensive Pleistocene ice sheet glaciation and both provide abundant geomorphological evidence of subglacial and postglacial processes. The Sea of the Hebrides bathymetry data cover 2200 km2 and provide new geomorphological evidence for an ice stream flowing from western Scotland and the Inner Hebrides focusing towards a trough-mouth fan (the Barra Fan) at the continental shelf break during the height of the last glaciation. Notably, bedrock structures provide a control on the location and orientation of glacially overdeepened basins and troughs on the inner shelf. Whilst around the Islands of Canna and Rum, convergent seabed glacial lineations and other subglacially streamlined features eroded in bedrock preserve the direction of ice sheet movement - indicating ice streaming in a south-westerly direction across the continental shelf. We propose that this fast-flow zone formed part of a larger convergent ice stream system draining much of western Scotland and the north of Ireland. The Firth of Lorn bathymetry acquisition comprises 553km2 of data, collected as part of the INIS Hydro program (Ireland, Northern Ireland and Scotland Hydrographic Survey). This region of nearshore continental shelf is revealed as predominantly bedrock-dominated seabed, characterised by a series of narrow, strongly fault-controlled troughs, part of the Great Glen Fault Zone complex. Evidence for glaciation is widespread and well preserved in the Firth of Lorn and surrounding seabed with moraines, bedrock lineations (?megagrooves?) and overdeepened basins common across the area. Initial mapping shows that our understanding of the configuration and style of deglaciation in these sectors of the former British-Irish Ice Sheet can be greatly improved by the collection of

  18. Tectonic geomorphological characteristics for evolution of the Manas Lake

    Institute of Scientific and Technical Information of China (English)


    Owing to global climatic changes and human activities,the lakes have changed dramatically in the Junggar Basin of Xinjiang in recent 50 years. Based on the remote sensing images from Beijing Satellite No.1 in 2006 together with the measured topographical data in 1999 and other data since the 1950s,this paper analyzes mainly the features of landforms around the Manas Lake and the changes of feeding sources of the lake. The results are as follows:(1) Tectonic movement brought about the fundamental geomorphological basis for lacustrine evolution,and the Manas Lake is one of small lakes broken up from the Old Manas Lake due to tectonic movement and drought climate; the Manas Lake had existed before the Manas River flowed into it in 1915. The geomorphologic evidences for evolution of the Manas Lake include:(a) Diluvial fans and old channels at the north of the lake indicate that the rivers originating from the north mountains of the Junggar Basin had fed the Old Manas Lake and now still feed the lake as seasonal rivers; (b) The Old Manas Lake was fed by many rivers originating from the mountains,except for the Manas River,from the evidence of small lakes around the Manas Lake,old channels,alluvial fans,etc.; (c) The elevations of the alluvial and diluvial fans are near to the 280 m a.s.l. and all of the small lakes and lacustrine plains are within the range of the 280 m a.s.l.,which may prove that the elevation of the Old Manas Lake was about 280 m a.s.l.; (d) Core analysis of the Manas Lake area also indicates that the Manas Lake has existed since Late Pleistocene epoch. (2) Analysis on the feeding relations between the lakes and the lacustrine evolution shows that human activities are one of main driving forces of the lacustrine evolution in recent 50 years,and it is the precondition of restoring and maintaining the lacutrine wetlands in the study area to satisfy the feeding of the Baiyang and Manas rivers to the Manas Lake.

  19. Disobedient sediments can feedback on their transportation, deposition and geomorphology (United States)

    Ginsburg, Robert N.


    Most sediments are obedient to the winds, waves and currents, which direct their transportation and deposition. It has long been recognized however, that the grain size, and/or grain kind, of sediments can feedback on the processes of their own transportation, deposition and geomorphology as well as that of succeeding deposits. This note is to review three examples of marine sediments in which a single grain size or grain kind produces multiple feedbacks. Tidal bars of Holocene ooid sands on Great Bahama Bank are an example of multiple feedbacks of one grain kind on tidal currents, wave action and accumulations. These feedbacks are responsible for the distinctive pattern of elongated bars and channels, which in turn amplify tidal currents. The near constant movement of grains on the shallow bars and in the channels is where pellet nuclei are coated to form ooids; thus the development and growth of bars feeds back to produce more ooids. Regional encrinites, which consist predominantly of the disarticulated highly porous skeletons of crinoids, are common from Ordovician to Jurassic during blooms of these filter feeders. The resulting grains, which are equivalent to quartz grains a tenth of their size, can be entrained by currents as low as a knot (ca 0.5 m/s). The resulting mobile substrate deters other invertebrates (taphonomic feedback) and results in the prevalence of layering produced by traction transport of low velocity. The belt of mud extending for some 1600 km between the Amazon and Orinocco rivers is a special example of the feedback of mud on depositional processes, sedimentary structures and geomorphology of the accumulations. The clay-rich mud from the Amazon produces fluid mud which dampens and transforms wave action from the open sea to promote its own accumulation in giant bars in the inner shelf and shoreline with a variety of familiar laminations. The result is a wedge of mud-rich deposits some 24 m thick and 30 km wide capped with cheniers of sand

  20. Pleistocene and Holocene geomorphological development in the Algarve, southern Portugal (United States)

    Chester, David K.


    A detailed chronological framework for Pleistocene and Holocene geomorphology and landscape evolution in the Algarve is proposed. With regards to the Pleistocene, attention has focused on the origin, dating and stratigraphy of the Ludo Formation. Subsuming the classifications of earlier writers, it is now proposed that during the Pliocene a marine transgression occurred across a tectonically controlled basin that was constrained by the mountains of the Algarve interior to the north. Fluvial sands were then deposited in a regressive phase during the late Pliocene/early Pleistocene, while braided streams operating under semi-arid conditions subsequently laid down sands and gravels in the middle and upper Pleistocene. Lying unconformably over the Ludo Formation is an alluvial deposit (Odiáxere gravels and Loulé sands) of late Pleistocene/early Holocene date that is found within the river valleys of the Algarve. In the early-Holocene (ca.10, 000-ca.7000 BP) and early late-Holocene (ca.5000-ca.3000 BP), the situation in the Algarve was one of climatic amelioration (i.e., warmer and wetter conditions), rising sea levels, vegetation colonization, soil development and towards the end of this period trenching of the Odiáxere gravels and Loulé sands. From ca.3000 BP evidence is abundant that humans became important geomorphological agents either acting on their own or in combination with climatic factors. From around 5000 BP, conditions became dryer and, between ca.3000 BP and ca.700 BP, clearance of land by pre-Roman, Roman, and especially Islamic agricultural settlers caused widespread erosion and the deposition of extensive spreads of topsoil dominated sediment within river valleys (i.e., the Holocene terrace) and in coastal estuaries. A period followed up to 1900 CE when agricultural practices were less damaging to the soil, erosion was reduced and the Holocene terrace - together with coastal and estuarine deposits - was incised. In the past century and under

  1. Use of the catena principle in geomorphological impact assessment: a functional approach

    NARCIS (Netherlands)

    Wolfert, H.P.


    An integral method for assessing geomorphological landscape qualities is presented, to be used in environmental impact assessments. Five groups of landform functions are distinguished in the Netherlands, an area of low relief: orientation functions, information functions, ordering functions,

  2. Sediment Texture and Geomorphology of the Sea Floor from Fenwick Island, Maryland to Fisherman's Island, Virginia (United States)

    U.S. Geological Survey, Department of the Interior — These data are a qualitatively derived interpretive polygon shapefile defining surficial sediment type and distribution, and geomorphology, for nearly 1,400 square...

  3. Terrain Modelling with GIS for Tectonic Geomorphology : Numerical Methods and Applications


    Jordan, Gyözö


    Analysis of digital elevation models (DEMs) by means of geomorphometry provides means of recognising fractures and characterising the morphotectonics of an area in a quantitative way. The objective of the thesis is to develop numerical methods and a consistent GIS methodology for tectonic geomorphology and apply it to test sites. Based on the study of landforms related to faults, geomorphological characteristics are translated into mathematical and numerical algorithms. The methodology is bas...

  4. A model for the geomorphology of the Carolina Bays (United States)

    Zamora, Antonio


    Geometrical analysis of the Carolina Bays using Google Earth in combination with LiDAR data makes it possible to postulate that the bays formed as the result of impacts, rather than from eolian and lacustrine processes. The Carolina Bays are elliptical conic sections with width-to-length ratios averaging 0.58 that are radially oriented toward the Great Lakes region. The radial distribution of ejecta is one characteristic of impacts, and the width-to-length ratios of the ellipses correspond to cones inclined at approximately 35°, which is consistent with ballistic trajectories from the point of convergence. These observations, and the fact that these geomorphological features occur only on unconsolidated soil close to the water table, make it plausible to propose that the Carolina Bays are the remodeled remains of oblique conical craters formed on ground liquefied by the seismic shock waves of secondary impacts of glacier ice boulders ejected by an extraterrestrial impact on the Laurentide Ice Sheet. Mathematical analysis using ballistic equations and scaling laws relating yield energy to crater size provide clues about the magnitude of the extraterrestrial event. An experimental model elucidates the remodeling mechanisms and provides an explanation for the morphology and the diverse dates of the bays.

  5. Geomorphological Impacts of an extreme Flood in Karoon River, Iran (United States)

    Yousefi, Saleh; Mirzaee, Somaya; Keesstra, Saskia; Piegay, Herve; Pourghasemi, Hamid Reza


    An extreme flood occurred on 14.04.2016 in Kroon River. Using the OLI Landsat images on 08.04.2016 (before flood) and 24.04.2016 (after flood) the morphological evolution in different land cover types by this flood event were detected. The results show that the event significantly affected the channel width. The main effect was the high mobilization of channel sediments and severe bank erosion in the studied meandering reach. According to field surveys, the flood occupied the whole channel corridor and even some of the flood plain parts, but the channel pattern was not markedly changed. Results show the average of active channel width increased from 192 m to 256 m respectively for before and after flood. Statistical results indicate a significant change for active channel width and sinuosity index at 99% confidence level for both indexes. Findings show that the channel morphological changes (channel widening) varied significantly in different land cover types along the Karoon River banks. Specifically, the channel has widened less in the residential areas than the other land cover types, which is the result of bank protection activities. Keywords: Remote sensing, fluvial geomorphology, floodplain management, river evolution.

  6. Geomorphological evidence for ground ice on dwarf planet Ceres (United States)

    Schmidt, Britney E.; Hughson, Kynan H.G.; Chilton, Heather T.; Scully, Jennifer E. C.; Platz, Thomas; Nathues, Andreas; Sizemore, Hanna; Bland, Michael; Byrne, Shane; Marchi, Simone; O'Brien, David; Schorghofer, Norbert; Hiesinger, Harald; Jaumann, Ralf; Hendrick Pasckert, Jan; Lawrence, Justin D.; Buzckowski, Debra; Castillo-Rogez, Julie C.; Sykes, Mark V.; Schenk, Paul M.; DeSanctis, Maria-Cristina; Mitri, Giuseppe; Formisano, Michelangelo; Li, Jian-Yang; Reddy, Vishnu; Le Corre, Lucille; Russell, Christopher T.; Raymond, Carol A.


    Five decades of observations of Ceres suggest that the dwarf planet has a composition similar to carbonaceous meteorites and may have an ice-rich outer shell protected by a silicate layer. NASA’s Dawn spacecraft has detected ubiquitous clays, carbonates and other products of aqueous alteration across the surface of Ceres, but surprisingly it has directly observed water ice in only a few areas. Here we use Dawn Framing Camera observations to analyse lobate morphologies on Ceres’ surface and we infer the presence of ice in the upper few kilometres of Ceres. We identify three distinct lobate morphologies that we interpret as surface flows: thick tongue-shaped, furrowed flows on steep slopes; thin, spatulate flows on shallow slopes; and cuspate sheeted flows that appear fluidized. The shapes and aspect ratios of these flows are different from those of dry landslides—including those on ice-poor Vesta—but are morphologically similar to ice-rich flows on other bodies, indicating the involvement of ice. Based on the geomorphology and poleward increase in prevalence of these flows, we suggest that the shallow subsurface of Ceres is comprised of mixtures of silicates and ice, and that ice is most abundant near the poles.

  7. Interactions between soil biota and the effects on geomorphological features (United States)

    Zaitlin, Beryl; Hayashi, Masaki


    The interaction of animals with abiotic features of their environment has long been known to cause alterations to geomorphic features, and these interactions may cause feedback loops that further alter geomorphic features and animal communities. This paper samples the literature on selected burrowing animals in western North America, and discusses the interactions of animals with abiotic features of the environment and with each other, and the resulting impacts on geomorphic features and each other. As expected, burrowing characteristics of animals influence geomorphological processes. For example, pocket gophers and certain ground squirrels that burrow horizontal tunnels on sloping grounds seem to have significant impacts on horizontal movement of soils, whereas prairie dogs and harvester ants have more impact on vertical movement of soils. Burrowing animals, in general, increase the patchiness of the environment, which creates localized patch habitat for other plants and animals, thereby increasing biodiversity at the landscape scale. Burrowing animals influence and are influenced by microbes: sylvatic plague wiped out large populations of prairie dogs, earthworms cause major changes in soil microflora, pocket gophers and harvester ants cause changes in mycorrhizal communities, which in turn impact plant communities.

  8. Fluvial geomorphology of the Middle Reach of the Huai River

    Institute of Scientific and Technical Information of China (English)

    Bang-yi YU; Peng WU; Jue-yi SUI; Xing-ju YANG; Jin NI


    The Middle Reach of the Huai River (MRHR) flows northeast into the Hongzehu Lake. Before entering the Hongzehu Lake, the Huai River has a braided channel which is shallow and wide, and the riverbed has a negative slope. Based on the characteristics of the MRHR, this river reach can be divided into the following sections: a quasi-straight (or mildly curved) section, a bend section, and a braided section. The majority of the MRHR is quasi-straight. In this paper, several parameters are used to assess the geomorphology of the MRHR. Statistical analyses are performed to establish a relationship between the span length“L”and channel width“B”for different channel patterns. The relationship between the meandering length “S” and bankfull channel width “B” is also derived. Results indicate that the bankfull channel width “B”, the bankfull cross sectional area “A” and the average flow depth“H”are mainly dependent on the dominant discharge in the channel. A relationship is derived that describes the dependency of the curvature radius“R”on the dominant discharge“Q”, water surface slope“J”and the turning angle“α”.

  9. A Hydro-geomorphological Disaster: Braunsbach Flood 2016 (United States)

    Wendi, D.; Öztürk, U.; Riemer, A.; Agarwal, A.; Hahn, I.; Lopez Tarazon, J. A.; Korup, O.


    Following an unusual torrential downpour on 29th May 2016 with a total precipitation of 105 mm fallen in just one day (in contrast to May and June monthly average which varies from 70-80 mm/ month), flood outburst with massive amounts of rubbles and muddy sediments has been witnessed in the south-western German town of Braunsbach. This flash flood, as the combination of surging water and intensive sediment, coming from around 42 landslides, remarkable river bank erosion and river bed incision, was responsible of smashing numerous buildings, cars and town facilities, leaving residents with damage and losses. The event triggered the team of researchers under the research training group NatRiskChange to conduct field surveys, collect available data and analyze the underlying causes, magnitude, process complexity and aftermath problems of the disaster. The present analysis emphasizes on the hydro-geomorphology, in which comparisons of the event and study catchment is made in contrast to similar past events and regional catchments. They include the estimation of removed sediments/ materials, meteorological overview and the assessment hydro-geological characteristics.

  10. Applicative limitations of sediment transport on predictive modeling in geomorphology

    Institute of Scientific and Technical Information of China (English)

    WEIXiang; LIZhanbin


    Sources of uncertainty or error that arise in attempting to scale up the results of laboratory-scale sediment transport studies for predictive modeling of geomorphic systems include: (i) model imperfection, (ii) omission of important processes, (iii) lack of knowledge of initial conditions, (iv) sensitivity to initial conditions, (v) unresolved heterogeneity, (vi) occurrence of external forcing, and (vii) inapplicability of the factor of safety concept. Sources of uncertainty that are unimportant or that can be controlled at small scales and over short time scales become important in large-scale applications and over long time scales. Control and repeatability, hallmarks of laboratory-scale experiments, are usually lacking at the large scales characteristic of geomorphology. Heterogeneity is an important concomitant of size, and tends to make large systems unique. Uniqueness implies that prediction cannot be based upon first-principles quantitative modeling alone, but must be a function of system history as well. Periodic data collection, feedback, and model updating are essential where site-specific prediction is required.

  11. Effects of alluvial knickpoint migration on floodplain ecology and geomorphology (United States)

    Larsen, Annegret; May, Jan-Hendrick


    Alluvial knickpoints are well described as erosional mechanism within discontinuous ephemeral streams in the semi-arid SW USA. However, alluvial knickpoints occur globally in a wide range of settings and of climate zones, including temperate SE Australia, subtropical Africa, and tropical Australia. Much attention has been given in the scientific literature to the trigger mechanisms of alluvial knickpoints, which can be summarized as: i) threshold phenomena, ii) climate variability and iii) land-use change, or to a combination of these factors. Recently, studies have focused on the timescale of alluvial knickpoint retreat, and the processes, mechanisms and feedbacks with ecology, geomorphology and hydrology. In this study, we compile data from a global literature review with a case study on a tropical river system in Australia affected by re-occurring, fast migrating (140 myr-1) alluvial knickpoint. We highlight the importance of potential water table declines due to channel incision following knickpoint migration, which in turn leads to the destabilization of river banks, and a shift in floodplain vegetation and fire incursion. We hypothesize that the observed feedbacks might also help to understand the broader impacts of alluvial knickpoint migration in other regions, and might explain the drastic effects of knickpoint migration on land cover and land-use in semi-arid areas.

  12. A tentative classification of paleoweathering formations based on geomorphological criteria (United States)

    Battiau-Queney, Yvonne


    A geomorphological classification is proposed that emphasizes the usefulness of paleoweathering records in any reconstruction of past landscapes. Four main paleoweathering records are recognized: 1. Paleoweathering formations buried beneath a sedimentary or volcanic cover. Most of them are saprolites, sometimes with preserved overlying soils. Ages range from Archean to late Cenozoic times; 2. Paleoweathering formations trapped in karst: some of them have buried pre-existent karst landforms, others have developed simultaneously with the subjacent karst; 3. Relict paleoweathering formations: although inherited, they belong to the present landscape. Some of them are indurated (duricrusts, silcretes, ferricretes,…); others are not and owe their preservation to a stable morphotectonic environment; 4. Polyphased weathering mantles: weathering has taken place in changing geochemical conditions. After examples of each type are provided, the paper considers the relations between chemical weathering and landform development. The climatic significance of paleoweathering formations is discussed. Some remote morphogenic systems have no present equivalent. It is doubtful that chemical weathering alone might lead to widespread planation surfaces. Moreover, classical theories based on sea-level and rivers as the main factors of erosion are not really adequate to explain the observed landscapes.

  13. Hybrid geomorphological maps as the basis for assessing geoconservation potential in Lech, Vorarlberg (Austria) (United States)

    Seijmonsbergen, Harry; de Jong, Mat; Anders, Niels; de Graaff, Leo; Cammeraat, Erik


    Geoconservation potential is, in our approach, closely linked to the spatial distribution of geomorphological sites and thus, geomorphological inventories. Detailed geomorphological maps are translated, using a standardized workflow, into polygonal maps showing the potential geoconservation value of landforms. A new development is to semi-automatically extract in a GIS geomorphological information from high resolution topographical data, such as LiDAR, and combine this with conventional data types (e.g. airphotos, geological maps) into geomorphological maps. Such hybrid digital geomorphological maps are also easily translated into digital information layers which show the geoconservation potential in an area. We present a protocol for digital geomorphological mapping illustrated with an example for the municipality of Lech in Vorarlberg (Austria). The protocol consists of 5 steps: 1. data preparation, 2. generating training and validation samples, 3. parameterization, 4. feature extraction, and 5. assessing classification accuracy. The resulting semi-automated digital geomorphological map is then further validated, in two ways. Firstly, the map is manually checked with the help of a series of digital datasets (e.g. airphotos) in a digital 3D environment, such as ArcScene. The second validation is field visit, which preferably occurs in parallel to the digital evaluation, so that updates are quickly achieved. The final digital and coded geomorphological information layer is converted into a potential geoconservation map by weighting and ranking the landforms based on four criteria: scientific relevance, frequency of occurrence, disturbance, and environmental vulnerability. The criteria with predefined scores for the various landform types are stored in a separate GIS attribute table, which is joined to the attribute table of the hybrid geomorphological information layer in an automated procedure. The results of the assessment can be displayed as the potential

  14. The pragmatic roots of American Quaternary geology and geomorphology (United States)

    Baker, Victor R.


    hypotheses, the latter having been suggested by experience with nature itself rather than by our theories of nature. These distinctions and methods were described in G.K. Gilbert's papers on "The Inculcation of Scientific Method by Example" (1886) and "the Origin of Hypotheses" (1896). Portions were elaborated in T.C. Chamberlin's "Method of Multiple Working Hypotheses" (1890) and his "method of the Earth Sciences" (1904); in W.M. Davis's "Value of Outrageous Geological Hypotheses" (1926); and in D. Johnson's "Role of Analysis in Scientific Investigation" (1933). American Quaternary geology and geomorphology have their philosophical roots in the pragmatic tradition, enunciated most clearly by C.S. Peirce, now recognized as the greatest American philosopher and considered by Sir Karl Popper to be one of the greatest philosophers of all time. Quaternary geology and geomorphology afford numerous examples of Peirce's "method" of science, which might be termed "the critical philosophy of common sense". The most obvious influence of pragmatism in geology, however, has largely been conveyed by the tradition of its scientific community. The elements of this tradition include a reverence for field work, a humility before the "facts" of nature, a continuing effort "to discriminate the phenomena observed from the observer's inference in regard to them", a propensity to pose hypotheses, and a willingness to abandon them when their consequences are contradicted by reality.

  15. Geomorphological context of the basins of Northwestern Peninsular Malaysia (United States)

    Sautter, Benjamin; Pubellier, Manuel; Menier, David


    Geomorphological context of the basins of Northwestern Peninsular Malaysia Benjamin Sautter, Manuel Pubellier, David Menier Department of Petroleum Geosciences, Universiti Teknologi PETRONAS CNRS-UMR 8538, Ecole Normale Supérieure, 24, Rue Lhomond, 75231, Paris Cedex 05, France Petroleum basins of Western Malaysia are poorly known and their formation is controlled by the Tertiary stress variations applied on Mesozoic basement structures. Among these are the Paleozoic-Mesozoic Bentong Raub, Inthanon, and Nan suture zones. By the end of Mesozoic times, the arrival of Indian plate was accompanied by strike slip deformation, accommodated by several Major Faults (Sagaing, Three Pagodas, Mae Ping, Red River, Ranong and Klong Marui Faults). Due to changes in the boundary forces, these areas of weakness (faults) were reactivated during the Tertiary, leading to the opening of basins in most of Sundaland. Within this framework, while most of the Sundaland records stretching of the crust and opening of basins (SCS, Malay, Penyu, Natuna, Mergui) during the Cenozoics, Peninsular Malaysia and the Strait of Malacca are considered to be in tectonic quiescence by most of the authors. We present the geomorphology of the Northwestern Malaysia Peninsula with emphasis on the deformations onshore from the Bentong Raub Suture Zone to the Bok Bak Fault, via the Kinta Valley, and offshore from the Port Klang Graben to the North Penang Graben. By analyzing Digital Elevation Model from ASTER and SRTM data, two main directions of fractures in the granitic plutons are highlighted: NW-SE to W-E sigmoidal faults and N-S to NE-SW linear fractures which seem to cross-cut the others. In the field in the area of the Kinta Valley (Western Belt, NW Peninsular Malaysia), granitic bodies show intense fracturation reflecting several stages of deformation. The granites are generally syntectonic and do not cut fully across the Late Paleozoic platform limestone. Two sets of fractures (NW-SE and NE

  16. Geomorphologic Structures on the South Cretan Margin, Greece (United States)

    Nomikou, Paraskevi; Lykousis, Vasilis; Alexandri, Matina; Rousakis, Grigoris; Sakellariou, Dimitris; Lampridou, Danai; Alves, Tiago; Ballas, Dionysios


    Geomorphologic Structures on the South Cretan Margin, Greece Nomikou P.1, Lykousis V.2, Alexandri M.2, Rousakis G.2, Sakellariou D.2, Lampridou D.1 , Alves T.3, Ballas D.2 1University of Athens, Department of Geology and Geoenvironment, Panepistimioupoli Zografou, 15784 Athens, Greece. 2Inst. of Oceanography, Hellenic Centre for Marine Research, Anavyssos, Greece. 33D Seismic Laboratory, School of Earth and Ocean Sciences, Cardiff University, Main Building-Park Place, CF10 3AT Cardiff, UK. The swath bathymetric survey of the South Cretan Margin has been conducted during the HERMES-1 (May-June 2005) and HERMES-2 (September-October 2005) cruises onboard R/V "AEGAEO" using the 20 kHz, SEABEAM 2120 system. High-resolution multibeam bathymetry outlines in unprecedented detail the shape and the morphological features of the region. One of the most dominant geomorphological structures of the southwest Cretan slope is the submarine Samaria Canyon (Western Cretan Trough) which is characterized by high relief steep walls and V-shaped cross sections. Despite the fact that the trough trends predominantly northeastward, with a central axis oriented from east to west, the head displays a north-trending hook termination on the continental shelf. The minimum depth of its axis is 1400 m and the thalweg ranges from 1500 to 3500m. In addition, abrupt alternation in the axial trend of the canyon is observed, accompanied by sharp changes in axial gradient and in the geometry of the canyon profile ending in a flat area of 3600 m depth. From Paleochora up to Sindonia, numerous small canyons trending N-S crosscut the steep Cretan southern margin, that reaches the 2000 m isobath. These are transversal to the main direction E-W of the slope. Furthermore, the detailed bathymetric map reveals the morphology of several troughs bounded by steep flanks. Their flat bottom may reach up to 3000m water depth. The most characteristic one, Ptolemy trough (eastern South Cretan Trough), is located in

  17. Geomorphology and Depositional Subenvironments of Gulf Islands National Seashore, Mississippi (United States)

    Morton, Robert A.; Rogers, Bryan E.


    The U.S. Geological Survey (USGS) is studying coastal hazards and coastal change to improve our understanding of coastal ecosystems and to develop better capabilities of predicting future coastal change. One approach to understanding the dynamics of coastal systems is to monitor changes in barrier-island subenvironments through time. This involves examining morphological and topographic change at temporal scales ranging from millennia to years and spatial scales ranging from tens of kilometers to meters. Of particular interest are the processes that produce those changes and the determination of whether or not those processes are likely to persist into the future. In these analyses of hazards and change, both natural and anthropogenic influences are considered. Quantifying past magnitudes and rates of coastal change and knowing the principal factors that govern those changes are critical to predicting what changes are likely to occur under different scenarios, such as short-term impacts of extreme storms or long-term impacts of sea-level rise. Gulf Islands National Seashore was selected for detailed mapping of barrier-island morphology and topography because the islands offer a diversity of depositional subenvironments and the islands' areas and positions have changed substantially in historical time. The geomorphologic and subenvironmental maps emphasize the processes that formed the surficial features and also serve as a basis for documenting which subenvironments are relatively stable, such as the beach ridge complex, and those which are highly dynamic, such as the beach and active overwash zones. The primary mapping procedures used supervised functions within a Geographic Information System (GIS) that classified depositional subenvironments and features (map units) and delineated boundaries of the features (shapefiles). The GIS classified units on the basis of tonal patterns of a feature in contrast to adjacent features observed on georeferenced aerial

  18. Effectiveness evaluation of flood defence structures in different geomorphological contexts (United States)

    Morelli, Stefano; Pazzi, Veronica; Fanti, Riccardo


    The flood risk in different geomorphological contexts of two less developed countries are investigated in order to evaluate the efficacy of the existing flood defence structures. In particular, a recent floodplain crossed by a wide meandering river and a narrow mountain valley flowed by creek with a torrential regime have been chosen for such analysis in North Albania and central Mexico, respectively. Both areas have been affected by disastrous floods in past years with considerable damages to properties and people. Some safety countermeasures have been performed over time, even if in a non-systematic way. For this reason, the current inclination to flood risk was assessed by means of a freeware software designed to perform one-dimensional (1D) hydraulic modelling for a full network of natural and anthropic channels (HEC-RAS software by Hydrologic Engineering Center River Analysis System). This new analyses take into account: i) the natural morphological variability along the river path, ii) the anthropic interventions on the fluvial dynamics, iii) the landscape appearance after the soil exploitation in the past years, and iv) all the changes induced by an exceeded informal urbanization. The reconstruction of the river and bordering areas geometric data was carried out according to the physical characteristics of the local environment: a bathymetric survey and near-river DGPS acquisitions for the open spaces of the Albanian floodplain, and traditional topographic methods for the highly vegetated Mexican valley. In both cases, the results show that the existing works are, on their own, poorly efficient in containing the predictable floods. Albanians levees seem underdimensioned, while the channelling works are too narrow to contain large amounts of water and solid transport as typical of the Mexican study area. Evidently, a new territorial planning is required in these areas, and some projects are now in place. However, it would be desirable that local authorities

  19. Interactions among hydrology, geomorphology and vegetation on dryland hillslopes (United States)

    Parsons, Anthony


    On dryland hillslopes vegetation is typically patchy, and areas bare of vegetation are likely to be either stony or crusted. These bare areas promote Hortonian runoff, the pathways of which interact with the patchy vegetation. This interaction leads to a characteristic microrelief. On hillslopes dominated by woody shrubs there is a pronounced across-slope microrelief in which shrubs sit atop mounds and intershrub areas form swales. This microrelief concentrates runoff into the swales resulting in relatively efficient, connected runoff pathways which concentrates erosion and sediment transport within the swales. On hillslopes dominated by grass there is a pronounced downslope microrelief of small steps and risers. These steps create a disconnected pattern of runoff that traps runoff and sediment behind clumps of grass providing both water and nutrients to the grass. Both ecosystems are dominated by positive feedbacks implying stability; yet records show that locations may switch from one ecosystem to the other. To understand the conditions under which such switches may occur we have developed a modelling framework for the analysis of ecosystem change in drylands that is rooted in the concept of connectivity and is derived from a detailed process-based understanding of interactions among hydrology, geomorphology and vegetation. The model has been implemented in the deserts of the American Southwest both to test hypotheses of the causes of the invasion of woody shrubs, and to test its ability to reproduce observed spatial differences in response to drought in the 20th century. The modelling results show the importance of local conditions in determining the susceptibility of a location to ecosystem change and the significance of grazing in causing such changes.

  20. Erosional nitrogen losses in a geomorphologically dynamic wet tropical watershed (United States)

    Weintraub, S. R.; Stallard, R. F.; Taylor, P.; Asner, G. P.; Townsend, A. R.


    In erosion-prone watersheds, the loss of nutrients associated with eroding topsoil can be substantial. Previous studies in a geomorphologically dynamic wet-tropical study site demonstrated elevated nitrogen availability, characterized by larger nitrate pools, higher 15-N enrichment, and higher rates of net and potential nitrification, on stable ridge-tops compared to N-poor steep hillslopes. In the current study, we sought to test whether these pronounced differences in N availability were correlated with spatial patterns of erosional N-export. In order to characterize N transport patterns within a small (12-hectare) forested watershed, we buried Gerlach troughs at approximately 15-meter intervals along a 100-meter long study hillslope, beginning at the ridge-slope break and continuing downslope toward the stream. We recovered and analyzed all soil, water, and detritus collected by these troughs over the course of one year and concurrently monitored rainfall and stream discharge. We also measured soil mineralogy, texture, and permeability (Ksat) at the topographic locations where troughs were installed. We observed distinct patterns in the nature and timing of downslope N transport, with shifts in the contribution of dissolved versus particulate losses both across the hillslope and with intensification of wet-season precipitation. Unlike the flat ridge-top, steeper downslope segments exported a substantial amount of N during the late wet season, approximately 85% of which was in particulate form. These slope fluxes help account for much of the watershed- scale losses of > 10 kg particulate N per hectare per year, quantified in a nearby stream. Soil mineralogic and hydraulic characteristics varied in concert with general N export patterns, implying different degrees of soil stability and the dominance of different soil water flowpaths in steeper versus flatter areas. In this forested landscape, geomorphic position determines overland N fluxes and likely couples N

  1. Geomorphological mapping in arid regions supported by the analysis of shrub patterns (United States)

    Hikel, H.; Jarmer, T.; Schwanghart, W.; Kuhn, N. J.; Yair, Y.; Shoshani, M.


    Arid and semi-arid areas are often covered by sparse and patchy vegetation with spatial patterns being related to water scarcity. The patterns are governed to a high degree by topography and substrate that in turn reflect prevalent geomorphological and hydrological processes. We hypothesize that this relation can be utilized to support geomorphological mapping in dryland areas. The aim of this study is to develop an approach towards automated geomorphological mapping in drylands at the hillslope scale. Geomorphological mapping was carried out at the experimental catchment site nearby Sede Boqer, Israel, along two hillslope transects. Twenty rectangular plots were surveyed to determine the percent vegetation cover. A ground based hyperspectral camera was used to image the transects with a spatial resolution of 0.05 cm. Plant canopy was obtained using a supervised classification. In addition, an aerial photo with a spatial resolution of 0.5 m was utilize to map plants at a larger spatial extent. Both datasets were used to calculate spatial pattern indices such as vegetation density, lacunarity, bare area fragmentation index and patch upslope side length/area ratio. All indices were investigated regarding their scale invariance with respect to the differently resolved datasets. Indices with a high degree of explanatory power and scale invariance were then used as variables in a decision tree model for automated geomorphological mapping. Preliminary results indicate that the spatial pattern indices can be used as an identification tool of geomorphological units and ecohydrological environments. The result suggests that geomorphological mapping in arid and semi-arid areas can be supported by vegetation detection using remote sensing and digital image processing.

  2. Geo-Morphological Analyses of the Gakkel Ridge and the Southwest Indian Ridge (United States)

    Dorschel, B.; Schlindwein, V. S. N.; Eagles, G.


    The Gakkel Ridge in the Arctic Ocean and the Southwest Indian Ridge in the Southwest Indian Ocean between Africa and Antarctica are ultraslow-spreading (intersticial melt migration) by which material rises to fill the space vacated by plate divergence. These ridges are characterised by non-orthogonal spreading. Transform faults, typical of faster spreading mid ocean ridges, are far less common at ultraslow spreading mid ocean ridges. Thus in return, detailed geo-statistical analyses of the geo-morphology of ultraslow-spreading mid ocean ridges can provide valuable information towards a better understanding of these slowest of spreading ridges. We have generated high resolution bathymetric grids for the Gakkel and Southwest Indian ridges based on high resolution multibeam echosounder data from various expeditions with RV Polarstern. On the basis of these grids, geo-statistical analyses allow for an assessment of the geo-morphological elements of the ridges on various scales. The results of these analyses show that, approximately 200 km long medium-scale sections of the ridges can be characterised by the lengths and orientations of the short-scale (hundreds of meters to tens of kilometres) ridges and troughs. The geomorphologies of short-scale ridges and troughs situated at the junctions between medium scale sections often exhibit a mixture of the geomorphological elements seen in the neighbouring sections. These geo-morphological patterns provide insights into the overall spreading-geometry along the Gakkel Ridge and the Southwest Indian Ridge.

  3. Technology and geomorphology: Are improvements in data collection techniques transforming geomorphic science? (United States)

    Viles, Heather


    In recent years technological developments have revolutionized our ability to collect data in geomorphology. Enhanced data collection not only enables us to provide deeper answers to a wider range of fundamental questions about the Earth's surface, but also encourages us to pose new questions. This paper considers in more detail the relationships between science, technology and the development of geomorphological tools and techniques, reviews the spectrum of tools and techniques now available to geomorphologists, and critically assesses what impact 'new technologies' are having on geomorphology. It focuses on the role of technology in biogeomorphology and weathering research, and how it is advancing theoretical, empirical and applied dimensions of these growing sub-fields of geomorphology. Five areas of important technological development are reviewed: remote sensing, dating, geophysical techniques, field and laboratory based analysis and sensing of physical and chemical characteristics, and field and laboratory based analysis of biological properties. There is good evidence that, taken together, technological developments are revolutionizing geomorphology through opening the doors to better cross-scalar investigations, blurring the boundaries between laboratory, field and computer model, and facilitating cross-disciplinary and democratized research.

  4. Geomorphologic Mapping of Titan's Polar Terrains: Constraining Surface Processes and Landscape Evolution

    CERN Document Server

    Birch, Samuel; Dietrich, William; Howard, Alan; Bristow, Charlie; Malaska, Michael; Moore, Jeff; Mastrogiuseppe, Marco; Hofgartner, Jason; Williams, David; White, Oliver; Soderblom, Jason; Barnes, Jason; Turtle, Elizabeth; Lunine, Jonathan; Wood, Charles; Neish, Catherine; Kirk, Randy; Stofan, Ellen; Lorenz, Ralph; Lopes, Rosaly


    We present a geomorphologic map of Titan's polar terrains. The map was generated from a combination of Cassini Synthetic Aperture Radar (SAR) and Imaging Science Subsystem imaging products, as well as altimetry, SARTopo and radargrammetry topographic datasets. In combining imagery with topographic data, our geomorphologic map reveals a stratigraphic sequence from which we infer process interactions between units. In mapping both polar regions with the same geomorphologic units, we conclude that processes that formed the terrains of the north polar region also acted to form the landscape we observe at the south. Uniform, SAR-dark plains are interpreted as sedimentary deposits, and are bounded by moderately dissected uplands. These plains contain the highest density of filled and empty lake depressions, and canyons. These units unconformably overlay a basement rock that outcrops as mountains and SAR-bright dissected terrains at various elevations across both poles. All these units are then superposed by surfici...


    Directory of Open Access Journals (Sweden)

    Maurício Mendes Von Ahn


    Full Text Available Geomorphological mapping allows the evaluation of geoheritage and subsidizes geoconservation efforts. This work aimed at identifying and analyzing the landforms at the Minas do Camaquã Geosite Protection Area (MCGPA – Rio Grande do Sul state – Brazil, emphasizing the anthropogenic morphologies to subsidize the conservation of the studied area’s geomorphological heritage. A geomorphological map (2015 of the MCGPA was made (1:25.000 to recognize and identify the natural and anthropogenic landforms. Based on this map, four sectors were identified according to the representativeness of the landforms: (1 Mineral extraction sector; (2 Tailings deposition sector; (3 Structural features sector; and (4 Boundary sector. The mining activities were the main reason for the geomorphological alterations and the creation of anthropogenic morphologies in the site. Despite the significant disturbance caused by the mining activity, there are still features of geologic-geomorphological interest fairly preserved. The identified and analyzed anthropogenic morphologies can describe the history of the mining activities that took place in the area and which formed a set of landforms currently present in the MCGPA. Although the surface features are not originated from natural morphogenesis, they belong to the area’s geodiversity. Furthermore, considering these features as geoheritage would create the need for management aiming at avoiding the collapse and degradation of these forms. Nowadays, the mining activities have remained inactive, and this set of anthropogenic morphologies need to be understood under a geomorphological point of view which will allow future exploitation of its potential touristic, scientific, pedagogical and cultural uses. The best way to promote and develop strategies of geoconservation for this place is to create and foment geotourism in this area.

  6. Geomorphological mapping and geophysical profiling for the evaluation of natural hazards in an alpine catchment

    Directory of Open Access Journals (Sweden)

    A. C. Seijmonsbergen


    Full Text Available Liechtenstein has faced an increasing number of natural hazards over recent decades: debris flows, slides, snow avalanches and floods repeatedly endanger the local infrastructure. Geomorphological field mapping and geo-electrical profiling was used to assess hazards near Malbun, a village potentially endangered by landslides, and especially debris flows. The area is located on the tectonic contacts of four different nappe slices. The bedrock consists of anhydrite and gypsum, dolomite, shale, marl, and limestone. The spatial distribution and occurrence of debris flows and slides is evaluated through a combination of geomorphological expert knowledge, and detailed visualization in a geographical information system. In a geo-database a symbol-based 1:3000 scale geomorphological map has been digitized and rectified into polygons. The polygons include information on the main geomorphological environment, the Quaternary material distribution and of geomorphological processes, which are stored in attribute tables. The spatial distribution of these attributes is then combined with geophysical information and displacement rates interpolated from benchmark measurements. On one of the landslides two geo-electrical profiles show that the distance to a potential failure plane varies between 10-20 m and that the topography of the failure plane is influenced by subterranean gypsum karst features. The displacement measurements show that this landslide actively disintegrates into minor slides and is not, therefore, a risk to the village of Malbun. The hazard zonation indicates that debris flows can pose a risk if no countermeasures are taken. Gypsum karst may locally accelerate the landslide activity. In contrast, the impact of debris flows is diminished because collapse dolines may act as sediment traps for the debris flow materials. This research illustrates how geomorphological expert knowledge can be integrated in a GIS for the evaluation of natural hazards

  7. Interactions between geomorphology and vegetation in the Western Swiss Alps: first investigations (United States)

    Giaccone, Elisa; Mariéthoz, Grégoire; Lambiel, Christophe


    The influence of earth surface processes can modify the microhabitat conditions and the species richness, composition and distribution patterns of plant communities. It is therefore important to understand how geomorphology affects the distribution of plant species to predict future vegetation evolution in a context of climate change. To better analyse the influence of geomorphology on vegetation growth in the alpine periglacial belt, we are studying various geomorphological processes (e.g. cryoturbation and solifluction), permafrost, nivation and ground surface characteristics at three focus sites of the Vaud Alps (Western Swiss Alps). The sites are located at an altitude range comprised between 2000 and 2600 m a.s.l. The geomorphology is characterized mainly by the presence of small glaciers, large moraine deposits, rock glaciers and debris slopes. Monitoring of the ground surface temperatures, permafrost mapping, vegetation survey and drone flights have been carried out to investigate in detail the environmental variables. Initial results show a heterogeneous vegetation cover depending on time since deglaciation, debris size, ground stability and soil age. Debris pioneer species are present on moraines, rock glaciers and debris slope; grassland are developed in zones not affected by LIA glacier advances or other interfering processes such as avalanches. The high-resolution images obtained from drone flights (5 cm/pixel) allow a detailed study of the granulometry. In order to use such geomorphological information on a wider area of interest, the local data acquired on focus sites have to be spatialized to a regional scale. This is accomplished by developing an approach based on remote sensing and multiple-point geostatistics that performs a semi-automated geomorphological mapping (SAGM). The SAGM is based on a training image composed by a geomorphological map yet existent, an orthophoto, the slope, the aspect, the curvature, the granulometry classification and

  8. A new symbol-and-GIS based detailed geomorphological mapping system: Renewal of a scientific discipline for understanding landscape development

    NARCIS (Netherlands)

    Gustavvson, M.; Kolstrup, E.; Seijmonsbergen, A.C.


    Abstract This paper presents a comprehensive and flexible new geomorphological combination legend that expands the possibilities of current geomorphological mapping concepts. The new legend is presented here at scale of 1:10,000 and it combines symbols for hydrography, morphometry/morphography,

  9. Using a Geospatial Model to Relate Fluvial Geomorphology to Macroinvertebrate Habitat in a Prairie River—Part 2: Matching Family-Level Indices to Geomorphological Response Units (GRUs

    Directory of Open Access Journals (Sweden)

    Anna Grace Nostbakken Meissner


    Full Text Available Many rivers are intensely managed due to anthropogenic influences such as dams, channelization, and water provision for municipalities, agriculture, and industry. With this growing pressure on fluvial systems comes a greater need to evaluate the state of their ecosystems. The purpose of this research is to use a geospatial model of the Qu’Appelle River in Saskatchewan to distinguish instream macroinvertebrate habitats at the family level. River geomorphology was assessed through the use of ArcGIS and digital elevation models; with these tools, the sinuosity, slope, fractal dimension, and stream width of the river were processed. Subsequently, Principal Component Analysis, a clustering technique, revealed areas with similar sets of geomorphological characteristics. These similar typology sequences were then grouped into geomorphological response units (GRUs, designated a color, and mapped into a geospatial model. Macroinvertebrate data was then incorporated to reveal several relationships to the model. For instance, certain GRUs contained more highly sensitive species and healthier diversity levels than others. Future possibilities for expanding on this project include incorporating stable isotope data to evaluate the food-web structure within the river basin. Although GRUs have been very successful in identifying fish habitats in other studies, the macroinvertebrates may be too sessile and their habitat too localized to be identified by such large river units. Units may need to be much shorter (250 m to better identify macroinvertebrate habitat.

  10. Multi-scale and object-oriented image analysis of high-res LiDAR data for geomorphological mapping in alpine mountains

    NARCIS (Netherlands)

    Anders, N.S.; Seijmonsbergen, A.C.; Bouten, W.; Purves, R.; Gruber, S.; Hengl, T.; Straumann, R.


    Geomorphological maps are useful to a wide variety of applications, such as hazard risk analysis (Seijmonsbergen 1992), forest ecological research (Van Noord 1996) and geoconservation evaluation studies (Seijmonsbergen et al. in press). Traditional field-based geomorphological mapping strategies are

  11. Multi-scale and object-oriented image analysis of high-res LiDAR data for geomorphological mapping in alpine mountains

    NARCIS (Netherlands)

    Anders, N.S.; Seijmonsbergen, A.C.; Bouten, W.; Purves, R.; Gruber, S.; Hengl, T.; Straumann, R.


    Geomorphological maps are useful to a wide variety of applications, such as hazard risk analysis (Seijmonsbergen 1992), forest ecological research (Van Noord 1996) and geoconservation evaluation studies (Seijmonsbergen et al. in press). Traditional field-based geomorphological mapping strategies are

  12. Geomorphological and Spectrophotometric Study of Philae Landing Site A (United States)

    Pajola, M.; La Forgia, F.; Giacomini, L.; Oklay, N.; Massironi, M.; Bertini, I.; Simioni, E.; Marzari, F.; Barbieri, C.; Naletto, G.; Groussin, O.; Lazzarin, M.; Scholten, F.; Preusker, F.; Fornasier, S.; Vincent, J. B.; Sierks, H.


    5 finalists, this site has the unique value to provide detailed analysis of the multiple fractures present on its cliff and on the neighboring Hathor. Figure 1: Site A as imaged by the OSIRIS NAC camera on 6 August 2014 at 02:20:12 UT. The distance from the comet center is 117.24 km, the scale is 2.17 m/px. EPSC Abstracts Vol. 10, EPSC2015-526, 2015 European Planetary Science Congress 2015 c Author(s) 2015 EPSC European Planetary Science Congress We here present the geomorphological map coupled with the size-frequency distributions of boulders # 2 m located on the different types of terrains here identified, such as outcropping layered terrains, gravitational accumulation deposits, taluses and fine particle deposits. Gravitational slopes, derived through the 67P shape model by assuming uniform density, have been used to characterize and better interpret the various terrains. Moreover, we show the spectrophotometric properties of the area, studied through images taken by OSIRIS NAC with a scale of 50 cm/px. Albedo maps, as well as surface reflectance spectra have been obtained by taking advantage of the shape model and DTM in order to correct for the illumination and observing conditions of the terrain. This multidisciplinary analysis highlights that different types of deposits show different photometric properties.

  13. Continental shelf drowned landscapes: Submerged geomorphological and sedimentary record of the youngest cycles

    NARCIS (Netherlands)

    Cohen, K.M.; Lobo, F.J.


    Continental shelves today find themselves largely submerged as a consequence of the sea-level rise in the last 20,000 years, the time since the Last Glacial Maximum (LGM), the period of maximum ice mass and minimum ocean volume within the Last Glacial Cycle. Their geomorphology, however, is far from

  14. Evaluation of Electromagnetic Induction (EMI) Resistivity Technologies for Assessing Permafrost Geomorphologies (United States)


    Currently, tools for identifying and mapping perma- frost structure and geomorphology in the subsurface are limited. Many of the current tools...F. S. Chapin III, S. F. Trainor,T. M. Barrett,P. F. Sullivan , A. D. McGuire, E. S. Euskirchen, P. E. Hennon, et al. 2011. Evidence and Implications

  15. The Geomorphology of the surroundings of the Ría de Arosa (Galicia, NW Spain)

    NARCIS (Netherlands)

    Pannekoek, A.J.


    This paper is intended to provide a geomorphological introduction to a series of papers on the sedimentology and weathering phenomena of the Ría de Arosa area. The area contains a large mass of coarse-grained porphyritic granite surrounded by other crystalline rocks. The granite is deeply weathered

  16. Biological control of pedological and hydro-geomorphological processes in a deciduous forest ecosystem

    NARCIS (Netherlands)

    Cammeraat, E.L.H.; Kooijman, A.M.


    This study describes the effect of soil fauna andvegetation on the development of landscapes and how these actually control soil formation, geomorphological development and hydrological response. The study area is located in a semi-natural deciduous forest on marl in Luxembourg, with a strong textur

  17. Quantitative geomorphology with geographical information systems (GIS) for evolving societies and science (United States)

    Gomez, C.; Oguchi, T.; Evans, I. S.


    Based on the two sessions on spatial analysis, GIS and geostatistics convened by T. Oguchi, I. Evans and C. Gomez at the 2013 International Association of Geomorphology in Paris, the conveners have edited two special issues on the topic: volume 242 and the present one.

  18. Habitat hydrology and geomorphology control the distribution of malaria vector larvae in rural Africa. (United States)

    Hardy, Andrew J; Gamarra, Javier G P; Cross, Dónall E; Macklin, Mark G; Smith, Mark W; Kihonda, Japhet; Killeen, Gerry F; Ling'ala, George N; Thomas, Chris J


    Larval source management is a promising component of integrated malaria control and elimination. This requires development of a framework to target productive locations through process-based understanding of habitat hydrology and geomorphology. We conducted the first catchment scale study of fine resolution spatial and temporal variation in Anopheles habitat and productivity in relation to rainfall, hydrology and geomorphology for a high malaria transmission area of Tanzania. Monthly aggregates of rainfall, river stage and water table were not significantly related to the abundance of vector larvae. However, these metrics showed strong explanatory power to predict mosquito larval abundances after stratification by water body type, with a clear seasonal trend for each, defined on the basis of its geomorphological setting and origin. Hydrological and geomorphological processes governing the availability and productivity of Anopheles breeding habitat need to be understood at the local scale for which larval source management is implemented in order to effectively target larval source interventions. Mapping and monitoring these processes is a well-established practice providing a tractable way forward for developing important malaria management tools.


    Directory of Open Access Journals (Sweden)

    Emre ÖZŞAHİN


    Full Text Available In this paper, the influences of geomorphological factors on the soil characteristics is studied on the basis of Ayvalıdere Basin. The fact that these relationships are examined within a sample basin constitutes the significance of the study. In this study, KIRKLARELI F19-d4 and BANDIRMA G19-a1 topographic maps on a scale of 1:25.000 are used. As to methodology, firstly the geomorphological characteristics of the basin area were identified. Afterwards, the detailed soil map of the area was formed by making use of the sample soil analyses by other researchers and the other study findings. Whether or not geomorpho- logical characteristics affect soil distribution in the basin was scrutinized by comparing and contrasting both geomorphological characteristics (landforms, slope, aspect, altitude and soil characteristics on GIS (Geographic Information Systems. It was found and emphasized as a result that the relationship between landforms and the soil characteristics significantly differs even in short distances. There is a need for more detailed research on this relationship. Thus, the obtained results may be used to take concrete steps for the conservation of soil resource and their proper use and planning. Finally, similar research on the rela- tionship between soil and the landforms dealing with pedological and geomorphological characteristics may help us to understand and analyze the natural environment better.

  20. Sedimentation within and among mangrove forests along a gradient of geomorphological settings

    NARCIS (Netherlands)

    Adame, Maria Fernanda; Neil, David; Wright, Sara F.; Lovelock, Catherine E.


    Coastal wetlands provide important ecological services to the coastal zone, one of which is sediment retention. In this study we investigated sediment retention across a range of geomorphological settings and across vegetation zones comprising coastal wetlands. We selected six coastal wetlands domin

  1. geomorphological mapping and geophysical profiling for the evaluation of natural hazards in an alpine catchment

    NARCIS (Netherlands)

    Seijmonsbergen, A.C.; de Graaff, L.W.S.


    Liechtenstein has faced an increasing number of natural hazards over recent decades: debris flows, slides, snow avalanches and floods repeatedly endanger the local infrastructure. Geomorphological field mapping and geo-electrical profiling was used to assess hazards near Malbun, a village potentiall

  2. geomorphological mapping and geophysical profiling for the evaluation of natural hazards in an alpine catchment

    NARCIS (Netherlands)

    Seijmonsbergen, A.C.; de Graaff, L.W.S.


    Liechtenstein has faced an increasing number of natural hazards over recent decades: debris flows, slides, snow avalanches and floods repeatedly endanger the local infrastructure. Geomorphological field mapping and geo-electrical profiling was used to assess hazards near Malbun, a village

  3. The Geomorphology of the surroundings of the Ría de Arosa (Galicia, NW Spain)

    NARCIS (Netherlands)

    Pannekoek, A.J.


    This paper is intended to provide a geomorphological introduction to a series of papers on the sedimentology and weathering phenomena of the Ría de Arosa area. The area contains a large mass of coarse-grained porphyritic granite surrounded by other crystalline rocks. The granite is deeply weathered

  4. Multi-Site Calibration of Linear Reservoir Based Geomorphologic Rainfall-Runoff Models

    Directory of Open Access Journals (Sweden)

    Bahram Saeidifarzad


    Full Text Available Multi-site optimization of two adapted event-based geomorphologic rainfall-runoff models was presented using Non-dominated Sorting Genetic Algorithm (NSGA-II method for the South Fork Eel River watershed, California. The first model was developed based on Unequal Cascade of Reservoirs (UECR and the second model was presented as a modified version of Geomorphological Unit Hydrograph based on Nash’s model (GUHN. Two calibration strategies were considered as semi-lumped and semi-distributed for imposing (or unimposing the geomorphology relations in the models. The results of models were compared with Nash’s model. Obtained results using the observed data of two stations in the multi-site optimization framework showed reasonable efficiency values in both the calibration and the verification steps. The outcomes also showed that semi-distributed calibration of the modified GUHN model slightly outperformed other models in both upstream and downstream stations during calibration. Both calibration strategies for the developed UECR model during the verification phase showed slightly better performance in the downstream station, but in the upstream station, the modified GUHN model in the semi-lumped strategy slightly outperformed the other models. The semi-lumped calibration strategy could lead to logical lag time parameters related to the basin geomorphology and may be more suitable for data-based statistical analyses of the rainfall-runoff process.

  5. Geomorphological map as a tool for visualisation of geodiversity - example from Cave Park Grabovaca (Croatia) (United States)

    Buzjak, Nenad; Bocic, Neven; Pahernik, Mladen


    Cave Park Grabovaca is located near Perusic in Lika region (central Croatia). It was established in 2006 at the area of 5.95 km2 (protection category: significant landscape). The main task is management and protection of Samograd, Medina and Amidzina caves that were declared as geomorphological monuments, and 6 other caves located close to each other. Owing to the central geographic location in Croatian Dinaric karst area, good traffic connections between central Europe and tourist centres of the Adriatic coast, preserved nature and easy accessible karst features typical for the Dinaric Karst, it has good potential to develop as an research, educational and tourist centre. In 2013. Cave Park management and the Department of Geography (University of Zagreb, Faculty of Science) established a core team that started to develop the project of Geoeducational centre (GEC) with following goals: exploration-evaluation-presentation-education. According to the accepted strategy, the first step in the project process is to enlarge the area and change the protection category. During the consultation process team members take into account protection, environmental, local economy, tourism and local population issues and proposed that protected area should be increased to 52,2 km2. This enlargement provides more efficient protection, greater geodiversity and biodiversity by occupying geotope, biotope, and landscape units typical for the whole Lika karst region. The next step was inventorying, evaluation, analysis and visualisation of geological, geomorphological and speleological phenomena. This 2 year task was made in cooperation between Croatian Geomorphological Society, Department of Geography, Speleological Society Karlovac and Caving Club Samobor. The inventory was made using field-work mapping and geotagged photographs, cave mapping and DEM analysis. It resulted in GIS oriented geodatabase consisting of geomorphological forms, processes and cave inventory. From those data

  6. Geomorphological map of glaciated gorges in a granitic massif (Gredos range, Central Spain). (United States)

    Campos, Néstor; Tanarro, Luis Miguel; Palacios, David


    A detailed geomorphological map on a 1:10,000 scale is presented for a high mountain area in Gredos range (Iberian Central System), this area is located in a granitic massif 160 km West of Madrid and comprises three gorges : La Vega, Taheña-Honda and La Nava. Only few detailed geomorphological maps of the Gredos range are available despite the wide diversity of landforms, in order to improve the understanding of this zone, this geomorphological map of the area has been produced, showing in detail the geomorphologic diversity of these gorges. The map was created with the aid of 25 cm resolution aerial photographs, 25 cm resolution satellite images, Iberpix 3D images provided by the Spanish National Geographic Institute and verified with field work. The landforms were delimitated with a stereoscope and satellite image pairs and digitized using GIS and CAD software, in some areas 3D glasses has been used with 3D images and the software Esri ArcScene. The landforms resulting from interpretation of aerial photographs and satellite images were classified using the IGUL (Institute of Geography, University of Lausanne) legend system (developed at the end of the 1980s) combined with the legend proposed by Peña et al. (1997) and some personal adaptations. The map legend includes 45 landforms divided into seven sections: structural, hydrography, fluvial, gravitative, glacial, nival and anthropic landforms. The use of both legend systems allows us to represent the landform types distributed over an area of 40 km2 and to identify the geomorphic processes involved in their morphogenesis, this variety of processes and landforms identified demonstrated that geomorphological cartography obtained by combining traditional image interpretation and GIS technology facilitates the production of geomorphological maps and the obtaining of valuable data for identify and understand surface processes and landforms. References: Maillard, B., Lambiel, C., Martin, S., Pellitero, R., Reynard, E

  7. Geomorphology and the urban tropics: building an interface between research and usage (United States)

    Gupta, Avijit; Ahmad, Rafi


    The developing countries, located almost entirely within the tropics, are currently undergoing urbanization at a rapid pace. Many of these cities are not more than a few centuries old, having been established to function as regional trading posts or administrative centers by either colonial or regional powers. It is doubtful that the site conditions were taken into consideration, and consequently, many of these cities were established in hazardous or environmentally sensitive areas. As these cities developed over time, they spread across a wide range of terrain conditions much of which are unsuitable, such as floodplains, coastal swamps, steep slopes, or sand dunes. For a number of these cities, which are located near active plate margins and tropical cyclone belts, such problems are magnified. Increased demand for water has required subsurface extraction, leading to problems of subsidence and quality. We examine the range of these cities with reference to (1) their site-related problems, (2) the nature of geomorphological information required for specific ameliorating actions, and (3) the level of management required for city maintenance. Management requires interfacing geomorphology with engineering practices and urban planning. We present case studies of cities ranging from those with limited problems and possible engineering and land-zoning solutions (Singapore) to cities where the hazards (either natural or anthropogenic) are so acute and widespread that a practical solution is difficult to achieve (Kingston, Bangkok). Precise geomorphological and geological information and long-term data sets are not available for most of the cities. Furthermore, it is necessary to present the information in formats appreciated by the engineering and planning communities. Often a set of specialized maps are extremely useful. We complete the discussion with several examples and suggestions for collection of geomorphological information and inventory preparation for

  8. Tectonic geomorphology of the Ryukyu Trench-Arc-Backarc System:geological-geophysical exploration and mapping

    Institute of Scientific and Technical Information of China (English)

    FU Mingzuo; LIU Lejun; ZHENG Yanpeng; LIU Baohua; WU Jinlong; XU Xiaowei


    Based on an analysis of full-cover multi-beam bathymetric data, seismic and sub-bottom profiling data, and other geological-geophysical data sets, the geomorphologic features of the Ryukyu trench-arc-backarc (T-A-BA) system are delineated, and a geomorphologic map of the system is compiled. The results show that the evolution and spatial distribution patterns of the geomorphologic types of the Ryukyu T-A-BA system are controlled mainly by tectonic movements. The tectonic geomorphologic characteristics of the Ryukyu Arc (RA) differ distinctly from those of the East China Sea (ECS) continental shelf and slope. In term of geological structures, RA consists of the Tokara volcanic ridge,the Ryukyu folded ridge, the fore-arc accretion-wedge ridge and the Amami Depression and the fore-arc depressions between the ridges, which is composed of a complex of alternating island-slope ridges and fault basins. The slope of the ECS is a passive continental margin with stepwise faults. The Okinawa Trough (OT) is a backarc rift in which tectonic movements are intensive, with active volcanic and hydrothermal eruptions and sea floor spreading. The development of geomorphic features of the OT is controlled by the central en echelon spreading axes, the faults along the ECS slope and the marginal faults to the west of the Tokara volcanic ridge.The geomorphic complex of the OT is arranged in the following pattern: the en echelon grabens and volcanic chains formed by rifting and spreading lie in the central part of the trough, the turbidite plains inclining eastwards-southeastwards from the slope foot of the ECS lie in the western-northwestern parts of the OT, and the volcaniclastic deposit plains inclining westward-northwestwards from the western slope foot of the RA lie in the eastern-southeastern parts of the OT. In term of tectonic geomorphology, the OT forms a natural division between the shelf of the ECS and the RA.

  9. Development of a new British Geologcial Survey(BGS) Map Series: Seabed Geomorphology (United States)

    Dove, Dayton


    BGS scientists are developing a new offshore map series, Seabed Geomorphology (1:50k), to join the existing 1:250k 'Sea Bed Sediments', 'Quaternary Geology', and 'Solid Geology' map series. The increasing availability of extensive high-resolution swath bathymetry data (e.g. MCA's Civil Hydrography Programme) provides an unprecedented opportunity to characterize the processes which formed, and actively govern the physical seabed environment. Mapping seabed geomorphology is an effective means to describe individual, or groups of features whose form and other physical attributes (e.g. symmetry) may be used to distinguish feature origin. Swath bathymetry also provides added and renewed value to other data types (e.g. grab samples, legacy seismic data). In such cases the geomorphic evidence may be expanded to make inferences on the evolution of seabed features as well as their association with the underlying geology and other environmental variables/events over multiple timescales. Classifying seabed geomorphology is not particularly innovative or groundbreaking. Terrestrial geomorphology is of course a well established field of science, and within the marine environment for example, mapping submarine glacial landforms has probably become the most reliable method to reconstruct the extent and dynamics of past ice-sheets. What is novel here, and we believe useful/necessary for a survey organization, is to standardise the geomorphological classification scheme such that it is applicable to multiple and diverse environments. The classification scheme should be sufficiently detailed and interpretive to be informative, but not so detailed that we over-interpret or become mired in disputed feature designations or definitions. We plan to present the maps at 1:50k scale with the intention that these maps will be 'enabling' resources for research, educational, commercial, and policy purposes, much like the existing 1:250k map series. We welcome feedback on the structure and

  10. Sedimentation within and among mangrove forests along a gradient of geomorphological settings (United States)

    Adame, María Fernanda; Neil, David; Wright, Sara F.; Lovelock, Catherine E.


    Coastal wetlands provide important ecological services to the coastal zone, one of which is sediment retention. In this study we investigated sediment retention across a range of geomorphological settings and across vegetation zones comprising coastal wetlands. We selected six coastal wetlands dominated by mangroves over a gradient from riverine to tidal settings in Southeast Queensland, Australia. Each site was comprised of three distinct vegetation communities distributed as parallel zones to the coast line: seaward fringe mangroves, landward scrub mangroves and saltmarsh/ cyanobacteria mat of the high intertidal zone. We measured suspended sediment retention and sedimentation rates. Additionally, in order to assess the origin of sediment transported and deposited in the mangroves, glomalin, a novel terrestrial soil carbon tracer, was used. Our results show a mean average sedimentation of 0.64 ± 0.01 mg cm -2 spring tide -1, which was variable within sites, regardless of geomorphological setting. However, geomorphological setting influenced spatial patterns of sediment deposition. Riverine mangroves had a more homogeneous distribution of sediments across the intertidal zone than tidal mangroves, where most sedimentation occurred in the fringe zone. Overall, the fringe zone retained the majority of sediment entering the coastal wetland during a tidal cycle with 0.90 ± 0.22 mg cm -2 spring tide -1, accounting for 52.5 ± 12.5% of the total sedimentation. The presence of glomalin in suspended sediments, and thus the relative importance of terrigenous sediment, was strongly influenced by geomorphological setting, with riverine mangroves receiving more glomalin in suspended solids than tidal mangroves. Glomalin was also differentially deposited within the vegetation zones at different geomorphological settings: primarily at the fringe zone of tidal mangroves and within the scrub zone of riverine mangroves. The differences we observed in the spatial distribution of

  11. The impact of geomorphology of marsh creeks on fish assemblage in Changjiang River estuary (United States)

    Jin, Binsong; Xu, Wang; Guo, Li; Chen, Jiakuan; Fu, Cuizhang


    Tidal marshes are an important habitat and nursery area for fish. In the past few decades, rapid economic development in the coastal areas of China has led to the interruption and destruction of an increasing number of tidal marshes. The growing interest in tidal marsh restoration has increased the need to understand the relationship between geomorphological features and fish assemblages in the design of marsh restoration projects. We studied temporal variations in, and the effects of creek geomorphological features on, the estuarine tidal creek fish community. Using modified channel nets, we sampled fish monthly from March 2007 to February 2008 from seven tidal creeks along an intertidal channel system in Chongming Dongtan National Nature Reserve. Fourteen creek geomorphological variables were measured or derived to characterize intertidal creek geomorphological features. The Gobiidae, with 10 species, was the most speciesrich family. The most abundant fish species were Liza affinis, Chelon haematocheilus, and Lateolabrax maculatus. The fish community was dominated by juvenile marine transients, which comprised about 80% of the total catch. The highest abundance of fish occurred in June and July, and the highest biomass occurred in December. Canonical redundancy analyses demonstrated that depth, steepness, cross-sectional area, and volume significantly affected the fish species assemblage. L. affinis favored small creeks with high elevations. Synechogobius ommaturus, Acanthogobius luridus, and Carassius auratus preferred deep, steep creeks with a large cross-sectional area and volume. These findings indicate that the geomorphological features of tidal creeks should be considered in the conservation and sustainable management of fish species and in the restoration of salt marshes.

  12. Assessing the effects of geomorphological processes on archaeological densities: a GIS case study on Zakynthos island, Greece

    NARCIS (Netherlands)

    Gouma, M.; van Wijngaarden, G.J.; Soetens, S.


    While geomorphological processes are considered key factors in the distribution of archaeological surface finds, few studies have attempted to quantify the relationship between artefact dispersal and erosional/depositional patterns. This paper compares Unit Stream Power Erosion Deposition model (USP

  13. Microlevel mapping of coastal geomorphology and coastal resources of Rameswaram island, India: A remote sensing and GIS perspective

    Digital Repository Service at National Institute of Oceanography (India)

    Nobi, E.P.; Shivaprasad, A.; Karikalan, R.; Dilipan, E.; Thangaradjou, T.; Sivakumar, K.

    . The impact of natural disturbances can be reduced by protecting the coast by green shielding. The present study was carried out to understand the coastal geomorphology and coastal resources of Rameswaram Island (Tamil Nadu, India), using Indian Remote Sensing...

  14. Geomorphological features and monitoring of a large and complex landslide near Avigliano urban area (South Italy

    Directory of Open Access Journals (Sweden)

    F. Sdao


    Full Text Available This paper reports the results of geological and geomorphological surveys and the first results of a still in progress GPS monitoring campaign, taken on a large and ancient landslide located near Avigliano town (Basilicata region, South Italy. The landslide occurs on structurally complex clayey-marly terrains and it is classifiable as a multiple and complex roto-translational-earthflow landslide. In the last years this landslide has been affected by frequent reactivations that have been the cause of grave damages to the urban structures in the area. During January 2004, in order to monitor the present kinematics of the landslide body, a GPS network was installed. Until today several GPS surveys have been carried out. The results of GPS data analysis show centimetres level motions going on the landslide. The final goal of the research will be to define a hazard evaluation and an evolution model of the landslide, using the integrated information coming from GPS and geomorphological surveys.


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    Thiago Morato de Carvalho


    Full Text Available The mean of this papper is to present the methodology used by SRTM products, like an essential tool toproducts in geomorphology. The mapping of Goiás State and Brasília D.C. from SIEG-GOIAS was usedlike example. The SRTM products were obtained by sensor SIR-C/X-SAR (Spaceborn Imaging RadarC-band/X-band Synthetic Aperture Radar on board of Endeavour space shuttle, during 2000, to mappingthe relief topography just the 80º. N an S parallels. The results showed which the SRTM images have agood utility to geomorphologic mappings in small and middle scales, like this application in the Goiás state,Brazil.

  16. On the application of SAR interferometry to geomorphological studies: estimation of landform attributes and mass movements (United States)

    Catani, Filippo; Farina, Paolo; Moretti, Sandro; Nico, Giovanni; Strozzi, Tazio


    This paper presents two examples of application of Synthetic Aperture Radar (SAR) interferometry (InSAR) to typical geomorphological problems. The principles of InSAR are introduced, taking care to clarify the limits and the potential of this technique for geomorphological studies. The application of InSAR to the quantification of landform attributes such as the slope and to the estimation of landform variations is investigated. Two case studies are presented. A first case study focuses on the problem of measuring landform attributes by interferometric SAR data. The interferometric result is compared with the corresponding one obtained by a Digital Elevation Model (DEM). In the second case study, the use of InSAR for the estimation of landform variations caused by a landslide is detailed.

  17. Geomorphologic and geologic overview for water resources development: Kharit basin, Eastern Desert, Egypt (United States)

    Mosaad, Sayed


    This study demonstrates the importance of geomorphologic, geologic and hydrogeologic assessment as an efficient approach for water resources development in the Kharit watershed. Kharit is one of largest watersheds in the Eastern Desert that lacks water for agricultural and drinking purposes, for the nomadic communities. This study aims to identify and evaluate the geomorphologic, geologic and hydrogeologic conditions in the Kharit watershed relative to water resource development using remote sensing and GIS techniques. The results reveal that the watershed contains 15 sub-basins and morphometric analyses show high probability for flash floods. These hazards can be managed by constructing earth dikes and masonry dams to minimize damage from flash floods and allow recharge of water to shallow groundwater aquifers. The Quaternary deposits and the Nubian sandstone have moderate to high infiltration rates and are relatively well drained, facilitating surface runoff and deep percolation into the underlying units. The sediments cover 54% of the watershed area and have high potential for groundwater extraction.

  18. Ecological Filtering and Plant Traits Variation Across Quarry Geomorphological Surfaces: Implication for Restoration (United States)

    Gilardelli, Federica; Sgorbati, Sergio; Armiraglio, Stefano; Citterio, Sandra; Gentili, Rodolfo


    Revegetation patterns after quarry abandonment have been widely studied from several ecological points of view, but a trait-based approach is still lacking. The aim of this study was to characterise the plant species assemblages and the associated functional traits filtered on different geomorphological surfaces in abandoned limestone quarry areas: artificial cliffs, embankments, and platforms. We then verified if species with certain traits were better able to overcome the dispersal and environmental filters necessary for establishment. To this aim, we analyzed 113 vegetation plots and collected data on 25 morphological, ecological, and dispersal traits to detect species adaptaions across these man-made environments. As a case study, we investigated the extraction basin of Botticino (Lombardy, Italy), the second largest in Italy. The results obtained by SIMPER and CCA analyses showed that rockiness, stoniness, slope, elevation, and time of surfaces are the main filters that varied across quarries and affected plant assemblages at the macro-scale level. Across the three geomorphological surfaces (meso-scale) of quarries, more specific abiotic filters selecting species were found. In turn, traits differentiation according to the three main geomorphological surfaces of quarry emphasized that further filters acting at the micro-scale imply differences in dispersal mechanisms and resource availability. This work highlighted the utility to study species assemblages and environmental filters to address quarry restoration according to the type of geomorphological surface. The investigation of some traits (chorological form, life forms, seed dispersal,s and plant height) can furnish some interesting indications for practice individuating further abiotic filters acting at the micro-scale.

  19. Landslide geomorphology: An argument for recognition, with examples from New Zealand (United States)

    Crozier, M. J.


    The role and significance that have been ascribed to landsliding within geomorphology were examined with respect to some of the influential historical concepts of landform evolution. Landsliding was almost completely ignored as a geomorphic process in the earliest models of landform evolution. While there has been a growing acknowledgement of landsliding as a hillslope process capable of performing significant erosion and transportation, it has received only sparse recognition as a formative process in its own right. Notable exceptions are the rarely referenced model of relief development of Skempton, A.W., 1953. Soil mechanics in relation to geology. Proceedings of the Yorkshire Geological Society 29 (3), 33-62 Pt.1 and the reply of Selby, M.J., 1974. Dominant geomorphic events in landform evolution. Bulletin International Association of Engineering Geology 9, 85-89 to the frequency-magnitude findings of Wolman, M.G., Miller, J.P., 1960. Magnitude and frequency of forces in geomorphic processes. Journal of Geology 68 (1), 54-74. Together, these two contributions provide a sound basis of geomechanical theory and ample empirical evidence to indicate that landslides have the potential to control landform evolution. It is proposed that landslide geomorphology systems exist, within which landslides dominate form and process by governing the mechanisms, rhythm, and pace of geomorphic change, in time and space. A review of New Zealand terrain suggests that these criteria are met in six distinctive landslide geomorphology systems. Each of these can be characterised not only by the landslide regime but also by the fundamental pre-conditions of tectonic setting and geology. It is argued that the existence of such systems and the complex interrelations involved require the recognition of a landslide geomorphology in its own right.

  20. Sandstone geomorphology of the Golden Gate Highlands National Park, South Africa, in a global context

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    Stefan W. Grab


    Full Text Available The Golden Gate Highlands National Park (GGHNP is well known for its impressive sandstone formations. While previous geoscience research in the park has focused on geology, palaeontology, slope forms and the prominent lichen weathering, remarkably little has been written on the diversity and possible origins of sandstone phenomena in the region. The objectives of this study were (1 to present a geomorphological map of prominent and interesting landforms for particular portions of the park and (2 to document the variety of macro- and microscale sandstone formations observed. During field work, we undertook global positioning system measurements to map landforms and, in addition, measured the dimensions of several landform types. A Schmidt hammer was used to conduct rock hardness tests at a variety of localities and lithologies for comparative purposes. We indentified and mapped 27 macro- and microscale sandstone landforms, of which 17 are described in detail. It is demonstrated that for the most part, the landforms are a likely product of surface lithological reactions to a regional climate characterised by pronounced multitemporal temperature and moisture shifts, recently and in the past. However, many of the geomorphological processes producing landforms are controlled by microclimates set up by factors such as macro- and microtopography. Conservation implications: The GGHNP is best known for its geological, geomorphological and palaeontological heritage. This paper highlights the diversity of sandstone geomorphological phenomena, many of them rare and ‘unique’ to the region. Not only are these landforms of aesthetic interest to tourists, but they also provide microhabitats for biota. Thus, conservation of biota requires associated conservation of geo-environments where they are established.

  1. Yangon River Geomorphology Identification and its Enviromental Imapacts Analsysi by Optical and Radar Sensing Techniques (United States)

    Lwin, A.; Khaing, M. M.


    The Yangon river, also known as the Rangoon river, is about 40 km long (25miles), and flows from southern Myanmar as an outlet of the Irrawaddy (Ayeyarwady) river into the Ayeyarwady delta. The Yangon river drains the Pegu Mountains; both the Yangon and the Pathein rivers enter the Ayeyarwady at the delta. Fluvial geomorphology is based primarily on rivers of manageable dimensions. The emphasis is on geomorphology, sedimentology of Yangon river and techniques for their identification and management. Present techniques such as remote sensing have made it easier to investigate and interpret in details analysis of river geomorphology. In this paper, attempt has been made the complicated issues of geomorphology, sedimentation patterns and management of river system and evolution studied. The analysis was carried out for the impact of land use/ land cover (LULC) changes on stream flow patterns. The hydrologic response to intense, flood producing rainfall events bears the signatures of the geomorphic structure of the channel network and of the characteristic slope lengths defining the drainage density of the basin. The interpretation of the hydrologic response as the travel time distribution of a water particle randomly injected in a distributed manner across the landscape inspired many geomorphic insights. In 2008, Cyclone Nargis was seriously damaged to mangrove area and its biodiversity system in and around of Yangon river terraces. A combination of digital image processing techniques was employed for enhancement and classification process. It is observed from the study that middle infra red band (0.77mm - 0.86mm) is highly suitable for mapping mangroves. Two major classes of mangroves, dense and open mangroves were delineated from the digital data.

  2. Drought Vulnerability Mapping with Geomorphological Approach in Yogyakarta Special Region (DIY) and Central Java (United States)



    This study aims to determine the level of vulnerability of the geomorphologic drought that occurred in Central Java and Yogyakarta Special Region. This study examines geomorphologic drought. Parameters used were slope, drainage, Available Water Capacity (AWC), permeability, landform, and land use. Landsat 8 and SRTM data were used for the extraction of physical parameters, such as slope, drainage, landform, and land use. The method used in this study is scoring and weighting. Query results were used for data classification by overlaying drought geomorphologic parameters. The expected outcome of this research is to map the geomorphologic drought vulnerability on Central Java and Yogyakarta Special Region. Drought vulnerability was divided into wet, normal and dry classes. Distribution of the dry class is frequent. Some of the dry classes are distributed on the steep till extremely steep slope region and on the structural and karsts landform. This was related to AWC value where region with high AWC contributed to the poor drainage of the soil, such as at Kulonprogo, Purworejo, Kebumen, Blora, Wonogiri, Purbalingga, Pekalongan, Jepara and Kudus regency. Normal classes are distributed on the sloping till steep slope, have moderate till well-drained soil and low AWC, such as at Gunung Kidul, Pati, Temanggung regency, and Magelang city. Wet classes are distributed on the flat or almost flat and sloping region. Most of the wet classes are distributed on volcanic hills and coastal area. Those regions are well-drained and the land uses are mostly for settlement and farming, such as at Sleman, Yogyakarta city, Klaten, Bantul, and Wonosobo regency.

  3. Benthic communities and geomorphology of the Tesoro Island Coral Reef, Colombian Caribbean


    Sánchez-M., Juan M.


    The benthic communities distribution in Tesoro Island (Colombian Caribbean) coral reef was determinad by cartography of reef morphology and functional groups from aerial photographs, theodolite triangulation, and bottom transects over depths ranging from O to 30 m. Tesoro Island is a sand cay reef developed over an emerged reef platform whose basal cone possibly originated by mud diapirism on the continental shelf. The benthic communities are distributed as subzones of the geomorphologic unit...

  4. Control of the geomorphology and gas hydrate extent on widespread gas emissions offshore Romania (Black Sea) (United States)

    Riboulot, V.; Cattaneo, A.; Sultan, N.; Ker, S.; Scalabrin, C.; Gaillot, A.; Jouet, G.; Marsset, B.; Thomas, Y.; Ballas, G.; Marsset, T.; Garziglia, S.; Ruffine, L.; Boulart, C.


    The Romanian sector of the Black Sea deserves attention because the Danube deep-sea fan is one of the largest sediment depositional systems worldwide and is considered the world's most isolated sea, the largest anoxic water body on the planet and a unique energy-rich sea. Due to the high sediment accumulation rate, presence of organic matter and anoxic conditions, the Black sea sediment offshore the Danube delta is rich in gas and thus show BSR. The cartography of the BSR over the last 20 years, exhibits its widespread occurrence, indicative of extensive development of hydrate accumulations and a huge gas hydrate potential. By combining old and new datasets acquired in 2015 during the GHASS expedition, we performed a geomorphological analysis of the continental slope north-east of the Danube canyon that reveals the presence of several landslides inside and outside several canyons incising the seafloor. It is a complex study area presenting sedimentary processes such as seafloor erosion and instability, mass wasting, formation of gas hydrates, fluid migration, gas escape, where the imprint of geomorphology seems to dictate the location where gas seep occurs. . Some 1409 gas seeps within the water column acoustic records are observed between 200 m and 800 m water depth. No gas flares were detected in deeper areas where gas hydrates are stable. Overall, 93% of the all gas seeps observed are above geomorphological structures. 78% are right above escarpment induced by sedimentary destabilizations inside or outside canyons. The results suggest a geomorphological control of degassing at the seafloor and gas seeps are thus constrained by the gas hydrates stability zone. The stability of the gas hydrates is dependent on the salinity gradient through the sedimentary column and thus on the Black Sea recent geological history. The extent and the dynamics of gas hydrates have a probable impact on the sedimentary destabilization observed at the seafloor.

  5. On the ability of plant life-history strategies to shape bio-geomorphologic interactions (United States)

    Schwarz, Christian; van Belzen, Jim; Zhu, ZhenChang; Bouma, Tjeerd; van de Koppel, Johan; Gourgue, Olivier; Temmerman, Stijn


    Previous work studying bio-geomorphologic interactions in intertidal habitats underlined the importance of wetland vegetation shaping their environment (e.g. tidal channel networks). Up to this point the potential of wetland vegetation to shape their environment was linked to their physical plant properties, such as stiffness, stem diameter or stem density. However the effect of life-history strategies, i.e. the mode of plant proliferation such as sexual reproduction from seeds, non-sexual lateral expansion or a combination of the former two was hitherto ignored. We present numerical experiments based on a wetland ecosystem present in the Western Scheldt Estuary (SW, the Netherlands) showing the importance of life-history strategies shaping bio-geomorphologic interactions. We specifically compare two extremes in life-history strategies, (1) one species solely establishing from seeds and relying on their mass recruitment (Salicornia europea); And a second species (Spartina anglica) which relies on a mixed establishment strategy consisting of seed dispersal and asexual lateral expansion through tillering, with a very low seed recruitment success per year. Based on conducted numerical experiments using TELEMAC2D we show that the Spartina-case facilitates relative low channel densities with pronounced channel networks, whereas the Salicornia-case favors high channel densities with less pronounced intertidal channels. The conducted numerical experiments are the first indication showing that plant proliferation strategies exert a major control on emerging patterns in bio-geomorphologic systems. This provides a deeper understanding in the constraining factors and dynamics shaping the emergence and resilience of bio-geomorphologic systems.

  6. Ecological filtering and plant traits variation across quarry geomorphological surfaces: implication for restoration. (United States)

    Gilardelli, Federica; Sgorbati, Sergio; Armiraglio, Stefano; Citterio, Sandra; Gentili, Rodolfo


    Revegetation patterns after quarry abandonment have been widely studied from several ecological points of view, but a trait-based approach is still lacking. The aim of this study was to characterise the plant species assemblages and the associated functional traits filtered on different geomorphological surfaces in abandoned limestone quarry areas: artificial cliffs, embankments, and platforms. We then verified if species with certain traits were better able to overcome the dispersal and environmental filters necessary for establishment. To this aim, we analyzed 113 vegetation plots and collected data on 25 morphological, ecological, and dispersal traits to detect species adaptaions across these man-made environments. As a case study, we investigated the extraction basin of Botticino (Lombardy, Italy), the second largest in Italy. The results obtained by SIMPER and CCA analyses showed that rockiness, stoniness, slope, elevation, and time of surfaces are the main filters that varied across quarries and affected plant assemblages at the macro-scale level. Across the three geomorphological surfaces (meso-scale) of quarries, more specific abiotic filters selecting species were found. In turn, traits differentiation according to the three main geomorphological surfaces of quarry emphasized that further filters acting at the micro-scale imply differences in dispersal mechanisms and resource availability. This work highlighted the utility to study species assemblages and environmental filters to address quarry restoration according to the type of geomorphological surface. The investigation of some traits (chorological form, life forms, seed dispersal,s and plant height) can furnish some interesting indications for practice individuating further abiotic filters acting at the micro-scale.

  7. The influence of geomorphology on the composition of aquatic flora and fauna withim a temporary pond network


    Florencio, Margarita; Serrano Martín, Laura; Siljestrom, Patricia; Fernández Zamundio, María del Rocio; García Murillo, Pablo; Díaz Paniagua, Carmen


    Geomorphological and hydrological features can provide a sound basis for global wetland classification. Temporary ponds located on the sandy area of Doñana can be classified into five different geomorphological areas. We hypothesised that these ponds would differ in soil characteristics, which may also explain differences in the composition of their macroinvertebrate, amphibian, and aquatic plant species assemblages. The study ponds were significantly segregated into southern and nor...

  8. Washover fans in the Exmouth Gulf (NW Australia) - chronostratigraphical and geomorphological investigations and palaeotempestological significance (United States)

    May, Simon Matthias; Brill, Dominik; Leopold, Matthias; Callow, Nik; Engel, Max; Opitz, Stephan; Scheffers, Anja; Brückner, Helmut


    Typically formed during barrier overwash or breaching and coastal inundation, washover fans represent depositional evidence of strong storms in most cases. While only few studies have investigated washover landforms in order to infer magnitude/frequency patterns of tropical cyclones (TCs) over millennial time scales, we here present a consistent chronostratigraphy of late Holocene washover fans in the Gulf of Exmouth (Western Australia). Using geomorphological, sedimentological and chronological investigations, combined with ground penetrating radar and unmanned aerial vehicle (UAV) survey techniques, we characterize the washover fans' geomorphology and stratigraphical architecture, document depositional processes involved in the washover formation, establish a chronostratigraphy based on optically stimulated luminescence (OSL), and evaluate the significance of the washover fans for inferring past (local to regional) TC activity. Multiple phases of washover fan reactivation are inferred based on sequences of sandy depositional units, related to TC-induced inundation, and intercalating palaeo-surfaces with incipient soil formation, suggesting reduced depositional activity. Our washover fans record TC deposition on millennial time scales, suggesting TC-induced deposition at 170, 360, 850 and 1300 as well as 1950, 2300, and 2850 years ago. Since this pattern of TC activity is consistent with data on late Holocene ENSO and SST patterns, we infer a regional palaeotempestological relevance of this unique geomorphological record.

  9. Uncertainties in the palaeoflood record - interpreting geomorphology since 12 500 BP (United States)

    Moloney, Jessica; Coulthard, Tom; Freer, Jim; Rogerson, Mike


    Recent floods in the UK have reinvigorated the national debate within academic and non-academic organisations of how we quantify risk and improve the resilience of communities to flooding. One critical aspect of that debate is to better understand and quantify the frequency of extreme floods occurring. The research presented in this study explores the challenges and uncertainties of using longer term palaeoflood data records to improve the quantification of flood risk. The frequency of floods has been studied on short (under 100 years) and long-time (over 200 years) scales. Long term flood frequency records rely on the radiocarbon dating and interpretation of geomorphological evidence within fluvial depositional environments. However, there are limitations with the methods used to do this. Notably, the use of probability distribution functions of fluvial deposits dates does not consider any other information, such as the geomorphological context of material and/ or the type of depositional environment. This study re-analyses 776 radiocarbon dated fluvial deposits from the UK, which have been compiled into a database, to interpret the geomorphological flood record. Initial findings indicate that even this large number of samples may be unsuitable for probabilistic methods and shows an unusual sensitivity to the number of records present in the database.

  10. Basin Scale Assessment of Landslides Geomorphological Setting by Advanced InSAR Analysis

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    Francesca Bozzano


    Full Text Available An extensive investigation of more than 90 landslides affecting a small river basin in Central Italy was performed by combining field surveys and remote sensing techniques. We thus defined the geomorphological setting of slope instability processes. Basic information, such as landslides mapping and landslides type definition, have been acquired thanks to geomorphological field investigations and multi-temporal aerial photos interpretation, while satellite SAR archive data (acquired by ERS and Envisat from 1992 to 2010 have been analyzed by means of A-DInSAR (Advanced Differential Interferometric Synthetic Aperture Radar techniques to evaluate landslides past displacements patterns. Multi-temporal assessment of landslides state of activity has been performed basing on geomorphological evidence criteria and past ground displacement measurements obtained by A-DInSAR. This step has been performed by means of an activity matrix derived from information achieved thanks to double orbital geometry. Thanks to this approach we also achieved more detailed knowledge about the landslides kinematics in time and space.

  11. Geomorphological and geophysical approach for locating favorable groundwater zones in granitic terrain, Andhra Pradesh, India. (United States)

    Dhakate, Ratnakar; Singh, V S; Negi, B C; Chandra, Subhash; Rao, V Ananda


    The increasing demand for fresh water has necessitated the exploration for new sources of groundwater, particularly in hard rock terrain, where groundwater is a vital source of fresh water. A fast, cost effective and economical way of exploration is to study and analyze remote sensing data. Interpreted remote sensing data was used to select sites for carrying out surface geophysical investigations. Various geomorphologic units were demarcated and the lineaments were identified by interpretation of remote sensing satellite images. The potential for occurrence of groundwater in the watershed areas was classified as very good, good, moderate and poor by interpreting the images. Sub-surface geophysical investigations, namely vertical electrical soundings, were carried out to delineate potential water-bearing zones. Integrated studies of interpretation of geomorphologic and geophysical data were used to prepare a groundwater potential map. The studies reveal that the groundwater potential of shallow aquifers is due to geomorphologic features and the potential of deeper aquifers is determined by lineaments such as faults and joints.

  12. Geomorphological Prerequisites of Recreation and Tourism Development in the Basin of Bolshaya Golubaya River

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    Vishnyakov Nikolay Vladimirovich


    Full Text Available The basin of the Bolshaya Golubaya river is a promising region for the development of recreation, due to the unique natural conditions and rich historical and cultural heritage of this territory. The article demonstrates geomorphological features of the basin of Bolshaya Golubaya and their influence on the prospects of recreational use of this area. The author analyses the literature data on the geomorphology of the region and supplements it with his own field studies. The nature of this region is picturesque and multifarious. There are a lot of ravines, gullies, terraces, chalk cliffs and other landforms here. The author discovers the opportunities of organization of different recreational types in the study area in light of its geomorphological features. Recreational characteristics of this territory make it suitable for hiking, skiing and cycling tourism, horse riding. The results of this research can be used at the stage of creating of tourist-recreational projects, when designing and conducting excursion trips, sports and health touristic events. These studies contribute to the expansion of practical knowledge about the geography of the territory which has a positive effect on the possibility of carrying out mentioned above recreational projects.

  13. Geomorphological analysis of sinkhole and landslide hazard in a karst area of the Venetian Prealps- Italy (United States)

    Tiberi, Valentina


    In the pedemountain area of the Asiago Plateau (Venetian Prealps - NE Italy) sinkholes and landslides represent in many cases a complex response to karst processes. Field survey showed that both soil and bedrock are involved, mainly represented by colluvial-alluvial sediments and carbonate rocks. Preliminary observations also reveal the key role of piping and cave-collapse phenomena and the importance of human remedial measures. Within study area, these processes cause damage mainly to agricultural and pasture activities and expose peoples and farm animals to very high hazards. This work provides preliminary results of geomorphological analysis carried out to define sinkhole and landslide hazard and his connections with karst processes. During first phases of the research program, an inventory of interesting phenomena has been elaborated employing GIS technologies. The database has been constantly revised and enriched with new field measurements and thematic maps (i.e. geomorphological, geo-structural, hydrogeological, caves development maps). Specifically, field survey focused on the morphodynamic definition of instability elements allowing to recognize a wide range of morphotypes (mainly with regard to sinkholes) and polygenic morphologies (i.e. mixed sinkholes-landslides configurations). Geomorphological analysis also revealed specific evolutionary trends of instability processes; they could be useful employed to program more effective mitigation strategies.

  14. Geomorphological analysis and classification of foredune ridges based on Terrestrial Laser Scanning (TLS) technology (United States)

    Fabbri, Stefano; Giambastiani, Beatrice M. S.; Sistilli, Flavia; Scarelli, Frederico; Gabbianelli, Giovanni


    Along the North Adriatic Sea coast (Italy), vulnerability to climate change is further aggravated by anthropogenic influences, such as strong subsidence rate due to deep groundwater and gas abstraction, tourism and industry impacts. In this context, conservation and restoration of coastal sand dunes become extremely important especially because of their importance in terms of 'natural' coastal defense. This paper proposes an innovative geomorphological approach based on Terrestrial Laser Scanning - TLS, which allows us to measure and monitor morphometric dune evolution with high precision and details. Several TLS surveys were performed along the Ravenna coast (Adriatic Sea, Italy) and the resulting Digital Elevation Models (DEMs) were analyzed in order to classify the foredune ridges in three geomorphological sub-zones. The topographic, areal and volumetric variations over time of geomorphological units were calculated by GIS tools in order to identify seasonal trends or particular pattern. Meteo-marine climate conditions were also analyzed and Principal Component Analysis (PCA) was performed to correlate changes in morphology with meteo-marine forcing factors, highlighting the ones that most influence dune evolution and dynamics.

  15. Applying fluvial geomorphology to river channel management: Background for progress towards a palaeohydrology protocol (United States)

    Gregory, K. J.; Benito, G.; Downs, P. W.


    Significant developments have been achieved in applicable and applied fluvial geomorphology as shown in publications of the last three decades, analyzed as the basis for using results of studies of environmental change as a basis for management. The range of types of publications and of activities are more pertinent to river channel management as a result of concern with sustainability, global climate change, environmental ethics, ecosystem health concepts and public participation. Possible applications, with particular reference to river channel changes, include those concerned with form and process, assessment of channel change, urbanization, channelization, extractive industries, impact of engineering works, historical changes in land use, and restoration with specific examples illustrated in Table 1. In order to achieve general significance for fluvial geomorphology, more theory and extension by modelling methods is needed, and examples related to morphology and process characteristics, integrated approaches, and changes of the fluvial system are collected in Table 2. The ways in which potential applications are communicated to decision-makers range from applicable outputs including publications ranging from review papers, book chapters, and books, to applied outputs which include interdisciplinary problem solving, educational outreach, and direct involvement, with examples summarized in Table 3. On the basis of results gained from investigations covering periods longer than continuous records, a protocol embracing palaeohydrological inputs for application to river channel management is illustrated and developed as a synopsis version (Table 4), demonstrating how conclusions from geomorphological research can be expressed in a format which can be considered by managers.


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    O. M. Kunah


    Full Text Available The role of geomorphological ecogeographical variables have been shown, which are received by means of the digital elevation model created on the basis of remote sensing data as markers of an ecological niche of weeds on an example common milkweed (Asclepias syriaca L.. The research range chooses territory which is in settlement Vovnjanka district (the Poltava region. The range has the linear sizes of 26 kilometres in a direction from the east on the west and 15 kilometres in a direction from the north on the south, the range total area makes 390 км2. As geomorphological variables the topographical wetness index, topographic position index, mass balance index, erosion LS-factor, direct and disseminated insolation, altitude above channel network, multiresolution valley bottom flatness, multiresolution ridge top flatness index, vector ruggedness measure have been considered. It is established, that on set of the geomorphological indicators received by means of digital model of a relief, it is possible to assert, that within a separate agricultural field a wide variety of microconditions which is caused by relief features is formed. Possibly, the variation of thermal and water modes, moisture redistribution, and also productivity mechanical processings of soil and efforts under the control of number of weeds make a background in which limits there is possible a moving of weed plants, including common milkweed.

  17. Using object-based geomorphometry for hydro-geomorphological analysis in a Mediterranean research catchment (United States)

    Guida, Domenico; Cuomo, Albina; Palmieri, Vincenzo


    The aim of the paper is to apply an object-based geomorphometric procedure to define the runoff contribution areas and support a hydro-geomorphological analysis of a 3 km2 Mediterranean research catchment (southern Italy). Daily and sub-hourly discharge and electrical conductivity data were collected and recorded during a 3-year monitoring activity. Hydro-chemograph analyses carried out on these data revealed a strong seasonal hydrological response in the catchment that differed from the stormflow events that occur in the wet periods and in dry periods. This analysis enabled us to define the hydro-chemograph signatures related to increasing flood magnitude, which progressively involves various runoff components (baseflow, subsurface flow and surficial flow) and an increasing contributing area to discharge. Field surveys and water table/discharge measurements carried out during a selected storm event enabled us to identify and map specific runoff source areas with homogeneous geomorphological units previously defined as hydro-geomorphotypes (spring points, diffuse seepage along the main channel, seepage along the riparian corridors, diffuse outflow from hillslope taluses and concentrate sapping from colluvial hollows). Following the procedures previously proposed and used by authors for object-based geomorphological mapping, a hydro-geomorphologically oriented segmentation and classification was performed with the eCognition (Trimble, Inc.) package. The best agreement with the expert-based geomorphological mapping was obtained with weighted plan curvature at different-sized windows. By combining the hydro-chemical analysis and object-based hydro-geomorphotype map, the variability of the contribution areas was graphically modeled for the selected event, which occurred during the wet season, by using the log values of flow accumulation that better fit the contribution areas. The results allow us to identify the runoff component on hydro-chemographs for each time step

  18. Geomorphological map of a coastal stretch of north-eastern Gozo (Maltese archipelago, Mediterranean Sea) (United States)

    Soldati, Mauro; Micallef, Anton; Biolchi, Sara; Chelli, Alessandro; Cuoghi, Alessandro; Devoto, Stefano; Gauci, Christopher; Graff, Kevin; Lolli, Federico; Mantovani, Matteo; Mastronuzzi, Giuseppe; Pisani, Luca; Prampolini, Mariacristina; Restall, Brian; Roulland, Thomas; Saliba, Michael; Selmi, Lidia; Vandelli, Vittoria


    Geomorphological investigations carried out along the north-eastern coast of the Island of Gozo (Malta) have led to the production of a detailed geomorphological map. Field surveys, accompanied by aerial photo-interpretation, were carried out within the framework of the EUR-OPA Major Hazards Agreement Project ``Developing Geomorphological mapping skills and datasets in anticipation of subsequent Susceptibility, Vulnerability, Hazard and Risk Mapping'' (Council of Europe). In particular, this geomorphological map is the main output of a `Training Course on Geomorphological Mapping in Coastal Areas' held within the Project in November 2016. The study area selected was between Ramla Bay and Dacrhlet Qorrot Bay on the Island of Gozo (67 km2), part of the Maltese archipelago in the central Mediterranean Sea. From a geological viewpoint, the stratigraphic sequence includes Late Oligocene (Chattian) to Late Miocene (Messinian) sedimentary rocks. The hard limestones of the Upper Coralline Limestone Formation, the youngest lithostratigraphic unit, dominate the study area. Underlying this formation, marls and clays belonging to the Blue Clay Formation extensively outcrop. The oldest lithostratigraphic unit observed in the study area is the Globigerina Limestone Formation, a fine-grained limestone. The lithostructural features of the outcropping units clearly condition the morphography of the landscape. The coast is characterised by the alternation of inlets and promontories. Worthy of notice is the large sandy beach of Ramla Bay partly backed by dunes. From a geomorphological perspective, the investigated coastal stretch is characterised by limestone plateaus bounded by steep structural scarps which are reshaped by gravitational and/or degradation processes, and milder slopes in Blue Clays at their foot comprising of numerous rock block deposits (rdum in Maltese) and active or abandoned terraced fields used for agricultural purposes. Landforms and processes related to

  19. Geotourist itineraries along the Italian territory: examples of mapping the geoheritage in different geomorphological and historical contexts (United States)

    Panizza, Valeria; Brandolini, Pierluigi; Laureti, Lamberto; Nesci, Olivia; Russo, Filippo; Savelli, Daniele


    In the framework of the studies dealing with geomorphosites mapping, many researches were carried out in the last years presenting both applied examples and proposals for tourist fruition. Researchers had to face many different challenges in transferring the knowledge about the geomorphological heritage on maps. The most relevant are those concerning the use of maps for tourist promotion, taking into account the requirements of clearness of representation of landforms and also the need of pointing out possible geomorphological hazards along tourist paths. Within the activity of the Working Group "Geomorphosites and Cultural Landscape" of AIGeo (Italian Association of Physical Geography and Geomorphology), some Italian itineraries, focused on the promotion of the geomorphological heritage by means of geotourist maps, are presented. They have the goal of: promoting landscape through its geomorphological and geological heritage; disseminating geoheritage knowledge focusing its relationships with cultural landscape and human history; assessing geomorphological hazards and possible risk situations The proposed itineraries are localised in different Italian regions and they concern: - the area around the remains of the Roman town of Ostra. The town is placed on the left side of the Misa River (Marche region, Italy), atop a stream terrace dating back to the uppermost Pleistocene-early Holocene. Detailed geomorphological field and remote-sensing mapping started in 2015. The surveying is aimed at focusing the geomorphological evolution as well as at assessing possible geomorphological hazard for both conservation and exploitation scopes. A geotourist trail is proposed with the aim of highlighting and integrating geomorphological and archaeological elements and information. - a geotourist trail along the coastal terraced slopes of Cinque Terre (Liguria, NW Italy): worldwide considered as one of the most outstanding examples of human integration with the natural landscape

  20. Introducing glacial geomorphology to secondary schools - an edutainment resource targeting the New Zealand curriculum (United States)

    Hemmingsen, Maree; Winkler, Stefan


    Outreach has become an important undertaking for many tertiary institutions and government agencies. Quite often universities and other tertiary institutions view outreach solely as a tool for the recruitment of future students or as a cost-effective way of meeting governmental obtruded institutional obligations towards community engagement. But for every serious scientist outreach should have an importance beyond that. Competent scientists value the opportunities that an effective outreach programme brings, to inform others of the significance of their particular discipline within the wider framework of science. In this context, glacial geomorphology and related fields of research constitute no exception. Although outreach activities seem to be becoming increasingly popular among scientists in New Zealand, there is still a lack of understanding of what is actually useful for the end user. Often what scientists assume will be useful for school is not. An effective outreach programme needs to be aligned to and represent the school curriculum, regardless of the fact that this may not always be the main focus of the scientist. The most successful resources are those which are developed in collaboration with teachers, by practitioners with an ability to develop outreach activities appropriate for "real" school life with all its restrictions. Sadly, all too often academics and scientists assume they know what schools want and what is important. We cannot stress highly enough that the resources produced need to be accessible to the teachers, who often lack a deep enough scientific background or do not have an appropriate confidence in their own scientific knowledge as well as meet the needs of their students. Frequently educators report their frustration when they cannot properly access resources or run simulations because of IT incompatibility or limited supportive guidance. Geomorphology and its individual sub-disciplines like e.g. glacial geomorphology has an

  1. The value of teaching about geomorphology in non-traditional settings (United States)

    Davis, R. Laurence


    Academics usually teach about geomorphology in the classroom, where the audience is enthusiastic, but generally small. Less traditional settings offer opportunities to reach a wider audience, one that is equally enthusiastic, given its love of geomorphic features in the National Parks, but one which has little knowledge of the science behind what they are seeing. I have "taught" geomorphology in four non-traditional settings: at a summer camp, a state wildlife refuge, on community field trips, and at meetings for clubs and government boards. This paper discusses my experiences and offers suggestions to others who may wish to follow this less-traveled educational path. As Head of Nature Programs at Camp Pemigewassett in New Hampshire, I have worked, over the last 33 years, with thousands of campers ranging from 8 to 15 years old. Our setting, in a glaciated valley on a small lake, exhibits a wide range of geomorphic features and offers many opportunities for direct learning through field investigations. I have found that even 8-year olds can do real science, if we avoid the jargon. Once "taught" they carry their knowledge about landforms and processes with them and eagerly share it with their friends and family on outings and trips, thus reaching an even wider public. Parks, wildlife refuges, nature preserves, and other similar areas generally have nature trails, often with educational information about the environment. Generally, interpretive signs are prepared by biologists and the content ignores the site's physical features, as well as the connections between ecological communities and the underlying geology and geomorphology. My students and I have addressed this situation at two places in Connecticut, one a state wildlife management area, also used for training teachers to teach Environmental Education, and the other, a town recreation area. We catalogued the geomorphic features, looked at relationships of the community level ecology to those features, and

  2. Geomorphologic mapping of titan's polar terrains: Constraining surface processes and landscape evolution (United States)

    Birch, S. P. D.; Hayes, A. G.; Dietrich, W. E.; Howard, A. D.; Bristow, C. S.; Malaska, M. J.; Moore, J. M.; Mastrogiuseppe, M.; Hofgartner, J. D.; Williams, D. A.; White, O. L.; Soderblom, J. M.; Barnes, J. W.; Turtle, E. P.; Lunine, J. I.; Wood, C. A.; Neish, C. D.; Kirk, R. L.; Stofan, E. R.; Lorenz, R. D.; Lopes, R. M. C.


    We present a geomorphologic map of Titan's polar terrains. The map was generated from a combination of Cassini Synthetic Aperture Radar (SAR) and Imaging Science Subsystem imaging products, as well as altimetry, SARTopo and radargrammetry topographic datasets. In combining imagery with topographic data, our geomorphologic map reveals a stratigraphic sequence from which we infer process interactions between units. In mapping both polar regions with the same geomorphologic units, we conclude that processes that formed the terrains of the north polar region also acted to form the landscape we observe at the south. Uniform, SAR-dark plains are interpreted as sedimentary deposits, and are bounded by moderately dissected uplands. These plains contain the highest density of filled and empty lake depressions, and canyons. These units unconformably overlay a basement rock that outcrops as mountains and SAR-bright dissected terrains at various elevations across both poles. All these units are then superposed by surficial units that slope towards the seas, suggestive of subsequent overland transport of sediment. From estimates of the depths of the embedded empty depressions and canyons that drain into the seas, the SAR-dark plains must be >600 m thick in places, though the thickness may vary across the poles. At the lowest elevations of each polar region, there are large seas, which are currently liquid methane/ethane filled at the north and empty at the south. The large plains deposits and the surrounding hillslopes may represent remnant landforms that are a result of previously vast polar oceans, where larger liquid bodies may have allowed for a sustained accumulation of soluble and insoluble sediments, potentially forming layered sedimentary deposits. Coupled with vertical crustal movements, the resulting layers would be of varying solubilities and erosional resistances, allowing formation of the complex landscape that we observe today.

  3. Investigating talus slope geomorphology as impacted by permafrost thaw (Valais, Switzerland): stipulating a research framework (United States)

    Hendrickx, Hanne; Delaloye, Reynald; Nyssen, Jan; Frankl, Amaury


    Climate change is altering temperature regimes and precipitation patterns worldwide. In the European Alps, atmospheric temperatures have risen twice as fast as the global average since 1900, while precipitation regimes are changing as well. Snow cover duration and extent has significantly decreased in the Swiss Alps, mainly due to earlier spring melt and rise in winter temperatures. Moreover, future projections predict a continuation of these trends. Spatial distribution and thermal properties of permafrost are highly influenced by ground surface conditions (snow and vegetation) and air temperature. Climate induced permafrost degradation is, therefore, expected. While alpine permafrost research has mainly focused on rock glaciers, less attention has been given to talus slopes. The latter are subjected to different kinds of slope processes such as debris flows, solifluction, permafrost creep, avalanches and rock fall. These processes are especially effective under a changing periglacial climate. Therefore, it is important to study permafrost distribution in these talus slopes, since it is believed to have large influence on slope stability. In this study, permafrost distribution will be mapped on several talus slope segments (10 - 40 ha) using geomorphological evidence, temperature data and measuring electrical resistivity tomography (ERT) profiles in addition to already existing data. The current dynamics of the study area will be studied by constructing detailed 3D models, using ground based and aerial photography (Unmanned Aerial Vehicles, UAV) and the Structure-from-Motion method (SfM). The resulting Digital Elevation Models (DEM) will be used to quantify and understand the current geomorphological processes acting on these talus slopes. Historical aerial and terrestrial photographs will be used to give an idea about the magnitude and frequency of past geomorphic processes (e.g. debris flows). Historical and current dynamics can then be compared and contrasted

  4. Hydrogeological processes in the Paris Basin: climate and geomorphologic impacts of the last five million years

    Energy Technology Data Exchange (ETDEWEB)

    Jost, A.; Violette, S.; Goncalves, J.; Marsily, G. de [Universite Pierre et Marie Curie, Sisyphe (UNIR CNRS 7619), 75 - Paris (France); Ledoux, E. [Ecole des Mines de Paris, Sisyphe (UNIR CNRS 7619, CIG, ENSMP), 77 - Fontainebleau (France); Guyomard, Y.; Robin, C.; Bonnet, St.; Guillocheau, F. [Rennes-1 Univ., Geosciences Rennes (UNIR CNRS 6118), 35 (France); Kageyama, M.; Ramstein, G. [Laboratoire des Sciences du Climat et de l' Environnement (UMR CEA-CNRS), Orme des Merisiers, 91 - Gif sur Yvette (France); Fauquette, S. [Montpellier-2 Univ., Institut des Sciences de l' Evolution de Montpellier (UNIR CNRS 5554) 34 (France); Favreb, E.; Such, J.P. [Universite Claude Bernard Lyon-1, PaleoEnvironnements et PaleobioSphere (UNIR CNRS 5125), 69 - Villeurbanne (France); Michelot, J.L. [OrsayTerre, FRE 2566, Faculte des Sciences, 91 - Orsay (France)


    The aim of the present study is to investigate the response of the Paris basin aquifer system to variations in its hydrodynamic boundary conditions on a time scale of several million years, trying to determine if the system has kept the memory of these past changes. Recent changes at a boundary are more especially of importance when considering its effects on groundwater flow in low-diffusivity regions, as it can generate a lasting transient flow, potentially responsible for abnormal pressures creation. For the purpose of this work, a 3D transient modelling of the Paris basin groundwater system has been developed using the code NEWSAM (ENSMP). The geometry and hydrodynamic input data of the model originate from previous studies on a basin model, NEWBAS (ENSMP), built to simulate the 248 My geological history of the basin. Both a geomorphologic and climatic scenarios have been established. Geomorphologic evolution is deduced from digital elevation model analysis, which allows to reconstruct the paleo-topography and measure river-valley incision and alpine orogenesis. Climate forcing results from a suite of paleo-climate modelling experiments using the LMDz atmospheric general circulation model (IPSL) with a refined spatial resolution centered on Paris, for the present, the Last Glacial Maximum (21 kyr BP) and the Middle Pliocene (3 My). The water balance is computed by a distributed hydrologic model, MODSUR (ENSMP). We present the simulated evolution of the transfers in the aquifer system in response to the altered boundary conditions induced by atmospheric and geomorphologic forcing, in the course of the last five million years. (authors)

  5. Discriminating impacts of geomorphological and human factors on vineyard soil erosion (Burgundy, France) (United States)

    Chevigny, Emmanuel; Quiquerez, Amélie; Petit, Christophe; Curmi, Pierre


    The Burgundy vineyards have been recognized for the high diversity of Terroirs, controlled by complex interactions between natural features, historical parameters and soil management practices. Vineyards are known to undergo substantial soil loss in comparison with other types of agricultural land. Hydric erosion on vineyards is controlled by complex interactions of natural and anthropogenic factors leading to intra-plot spatial heterogeneities of topsoil at a scale of a metre. Studying the relationship between soils and their degradation is crucial in this situation where soil sustainability is threatened. This study explores the relative influences of historical and present-day anthropogenic factors and geomorphological processes controlling soil erosion on vineyard hillslopes. The selected area was located in the Monthelie vineyard (Côte de Beaune, France) where intensive erosion occurred during high-intensity rainfall events. Soil erosion quantification was performed at a square-metre scale using dendrogeomorphology. This method is based on the measurement of the unearthing of the stock located on the vine plants, considered as a passive marker of soil-surface vertical displacement since the year of plantation. The obtained maps, together with various complementary datasets, such as geological and geomorphological data, but also historical documents (cadastral plans, cadastral matrices and old aerial photographs) allow landscape evolution to be assessed. The combination of all these data shows that spatial distribution and intensity of erosion are controlled mainly by lithology and slope value. However, our study highlights that the sediment dynamics in this vineyard plot is highly related to historical former plot limits and present-day management practices. Nonetheless, quantification of sediment dynamic for the last decade reveals that the impacts of historical structures are disappearing gradually, in response to present-day management practices and

  6. Geomorphological diversity of Dong-Sha Atoll based on spectrum and texture analysis in high resolution remote sensing imagery (United States)

    Chen, Jianyu; Mao, Zhihua; He, Xianqiang


    Coral reefs are complex marine ecosystems that are constructed and maintained by biological communities that thrive in tropical oceans. The Dong-Sha Atoll is located at the northern continental margin of the South China Sea. It has being abused by destructive activity of human being and natural event during recent decades. Remote sensing offers a powerful tool for studying coral reef geomorphology and is the most cost-effective approach for large-scale reef survey. In this paper, the high-resolution Quickbird2 imageries which covered the full atoll are used to categorize the current distribution of coral reefs geomorphological structure therein with the auxiliary SPOT5 and ASTER imageries. Spectral and texture analysis are used to distinguish the geomorphological diversity during data processing. The Gray Level Co-occurrence Matrices is adopted for texture feature extraction and atoll geomorphology mapping in the high-resolution pan-color image of Quickbird2. Quickbird2 is considered as the most appropriate image source for coral reefs studies. In the Dong-Sha Atoll, various dynamical geomorphologic units are developed according to wave energy zones. There the reef frame types are classified to 3 different types according as its diversity at the image. The radial structure system is the most characteristic and from high resolution imagery we can distinguish the discrepancy between them.

  7. Geomorphological dynamics of Deception Island (Maritime Antarctic): a GIS based analysis of the Cerro de la Cruz - Crater Lake area (United States)

    Melo, R.; Vieira, G.; Rocha, J.; Caselli, A.; Batista, V.; Ramos, M.


    This study, based on field surveying from the austral summer of 2007-2008, presents the first results of the detailed geomorphological mapping of Deception Island (South Shetlands, Antarctic Peninsula). The main objective is to provide new geomorphological observations aiming to understand: i) how climate change is affecting permafrost, ii) the interactions between volcanoes and permafrost and also, iii) the present-day geomorphological dynamics in an area of high environmental sensitivity. The detailed geomorphological mapping was made in the area between the Argentinean base of Decepción and the Spanish Base Gabriel de Castilla, corresponding to 4 km2, as well as in the vicinity of the ruins of the Chilean Refuge. Mapping focused on landforms and deposits that may be indicators of permafrost dynamics, such as rockfalls, gullies, debris flows, thermokarst depressions and lag surfaces. Active layer thickness was monitored during the summer in two sites with different topographic conditions using mechanical probing. The spatial distribution of the geomorphological processes and landforms was studied using a GIS, with the objective to study the controls of several independent variables, such as altitude, aspect, slope, topographical parameters and net summer radiation.

  8. Constraints on the nature of various Titan Geomorphological Units with Cassini/VIMS and SAR (United States)

    Solomonidou, Anezina; Coustenis, Athena; Lopes, Rosaly M. C.; Rodriguez, Sébastien; Schmitt, Bernard; Philippe, Sylvain; Malaska, Michael; Lawrence, Kenneth J.; Janssen, Michael A.; Le Gall, Alice; Jaumann, Ralf; Sohl, Frank; Stephan, Katrin; Drossart, Pierre; Brown, Robert H.; Maltagliati, Luca; Bratsolis, Emmanuel; Matsoukas, Christos


    We investigate the lower atmosphere of Titan from Visual and Infrared Mapping Spectrometer (VIMS) spectro-imaging data by use of a recently updated radiative transfer code in the near-IR range and RADAR/SAR data for the distinction of geomorphological units. We focus here on the geological major units identified in [1;2] and [3]: mountains, plains, labyrinths, dune fields, and possible cryovolcanic and/or evaporitic features (the latter two are albedo features, [4;5;6]). We infer surface properties (like absolute surface albedo and morphology) and atmospheric contributions, in particular the haze content. We find that the Huygens landing site and the candidate evaporitic regions pair compositionally with the variable plains, thus indicating that units of significant geomorphological differences seem to consist of very similar materials. Similarly for the labyrinth terrains and the undifferentiated plains. On the contrary, many regions from the same geomorphological unit show compositional variations depending on location (i.e. undifferentiated plains). These differences provide implications on the endogenic or exogenic origin of the various units. In previous studies we showed that the processes most likely linked to the formation of the various geomorphological units are aeolian, fluvial, sedimentary, and lacustrine, in addition to the deposition of organics through the atmosphere. Currently, we are working on deriving information on the chemical composition of the aforementioned regions from the extracted surface albedos using an extensive library of ices and tholins [e.g. 7]. This will shed light on the potential formation processes (Solomonidou et al. in prep.). Preliminary results on the chemical composition of the regions that have shown temporal changes (i.e. Tui Regio and Sotra Patera; [6]) are also presented.References: [1] Lopes, R.M.C., et al.: Icarus, 205, 540-558, 2010; [2] Lopes, R.M.C., et al.: Icarus, 270, 162-182, 2016; [3] Malaska, M., et al

  9. Irrigation channels of the Upper Rhone valley (Switzerland). Geomorphological analysis of a cultural heritage (United States)

    Reynard, Emmanuel


    The Upper Rhone valley (Canton of Valais, Switzerland) is characterised by dry climatic conditions that explain the presence of an important network (about 800 km) of irrigation channels - called Bisses in the French-speaking part of the canton or Suonen in the German-speaking area - dating back to the Middle Ages. This network constitutes a cultural heritage and during the last 30 years these agricultural infrastructures have sparked a renewed interest for tourist and cultural reasons. Indeed, the paths along the channels are used as tourist trails and several abandoned channels have been renovated for tourist use. Based on an inventory of the Bisses/Suonen of Valais, the proposed communication has three aims: (1) to analyse the geomorphological context (morphometric analysis, structural geomorphology, main processes) of various types of channels and to show the impact of the geomorphological context on the building techniques; (2) to identify particularly active processes along the channels; (3) to classify the Bisses/Suonen according to their geomorphological value and to their geomorphological sensitivity, and to propose managing measures. Structural and climatic conditions influence the geomorphological context of the channels. In a structural point of view, irrigation channels are developed in three main contexts: (1) in the Aar Massif crystalline basement; (2) in the limestone and marl cover nappes of the Helvetic Alps; (3) in the metamorphic cover nappes of the Penninic domain. The Rhone River valley is boarded by two high mountain ranges: the Penninic Alps in the South and the Bernese Alps in the North. Because of rain shadow effects, the climate is relatively dry and, between Brig and Martigny, annual rainfall is not more than 600 mm at 500 m ASL and 800 mm at 1600 m ASL. Nevertheless, due to important vertical precipitation gradients annual rainfall totals are high at high altitudes. On the southern facing tributary valleys, the dry climatic conditions

  10. Using the glacial geomorphology of palaeo-ice streams to understand mechanisms of ice sheet collapse (United States)

    Stokes, Chris R.; Margold, Martin; Clark, Chris; Tarasov, Lev


    Processes which bring about ice sheet deglaciation are critical to our understanding of glacial-interglacial cycles and ice sheet sensitivity to climate change. The precise mechanisms of deglaciation are also relevant to our understanding of modern-day ice sheet stability and concerns over global sea level rise. Mass loss from ice sheets can be broadly partitioned between melting and a 'dynamic' component whereby rapidly-flowing ice streams/outlet glaciers transfer ice from the interior to the oceans. Surface and basal melting (e.g. of ice shelves) are closely linked to atmospheric and oceanic conditions, but the mechanisms that drive dynamic changes in ice stream discharge are more complex, which generates much larger uncertainties about their future contribution to ice sheet mass loss and sea level rise. A major problem is that observations of modern-day ice streams typically span just a few decades and, at the ice-sheet scale, it is unclear how the entire drainage network of ice streams evolves during deglaciation. A key question is whether ice streams might increase and sustain rates of mass loss over centuries or millennia, beyond those expected for a given ocean-climate forcing. To address this issue, numerous workers have sought to understand ice stream dynamics over longer time-scales using their glacial geomorphology in the palaeo-record. Indeed, our understanding of their geomorphology has grown rapidly in the last three decades, from almost complete ignorance to a detailed knowledge of their geomorphological products. Building on this body of work, this paper uses the glacial geomorphology of 117 ice streams in the North American Laurentide Ice Sheet to reconstruct their activity during its deglaciation ( 22,000 to 7,000 years ago). Ice stream activity was characterised by high variability in both time and space, with ice streams switching on and off in different locations. During deglaciation, we find that their overall number decreased, they occupied a

  11. Geomorphological effects of plate movemen during Quaternary in China's tropics

    Institute of Scientific and Technical Information of China (English)

    ZHANGWeiqiang; HUANGZhenguo


    The eastern and western fronts of plate movement in Taiwan Island and Tibetan Plateau respectively are the two major sources of tectonic force for the morphogensis during Quaternary in China's tropics. Seven examples of geomorphological effects of plate movement are enumerated to discuss the differentiation of tectonic landforms in space and time during Quaternary. The tectonic movement tends to be more active since middle Pleistocene. Some phenomena such as the arc-shape mountain systems, volcanism and crustal deformation imply that the juncture zone of eastern and western tectonic forces is located at about 110°E.

  12. Volcanic and glacial evolution of Chachani-Nocarane complex (Southern Peru) deduced from the geomorphologic map. (United States)

    Alcalá, J.; Zamorano, J. J.; Palacios, D.


    The Chachani-Nocarane (16°11'S; 71°31'W; 6.057 m asl) is a large volcanic complex located in the western Central-Andean Cordillera, South of Peru. The date of the last eruption is not known and there are no registers of recent volcanic activity. The complex is shaped by glacial forms belonging to different phases, and periglacial forms (several generations of rock glaciers) which alternate with volcanic forms. The aim of this research is to establish the glacio-volcanic evolution of the volcanic complex Chachani-Nocarane. In order to do so, a detailed 1:20.000 scale geomorphological map was elaborated by integrating the following techniques: interpretation of the 1:35.000 scale aerial photographs (Instituto Geográfico Nacional de Perú, 1956) and the analysis of satellite images (Mrsid; NASA, 2000). Finally, the cartography was corrected though field work campaigns. Through the geomorphologic analysis of the landforms and their relative position, we have identified twelve phases, seven volcanic and five glacial phases. The most ancient volcanic phase is locate to the north area of the study area and correspond with Nocarane and Chingana volcanoes, alignment NW-SE. Above those ensemble the rest of the large delimited geomorphological units overlap. The most recent is located to the SW and consists of a complex series of domes, lava cones and voluminous lavas. Within the glacial phases, the most ancient one is related to the Last Glacial Maximum during the Pleistocene. Over this period, glaciers formed moraines from 3150 to 3600 m asl. The most recent glacier pulsation corresponds to the Little Ice Age (LIA). The moraines related to that event are the closest to the summits, located between 5.100 and 5.300 m asl, and they represent the last trace of glacial activity on the volcanic complex. Currently, this tropical mountain does not have glaciers. The only solid-state water reserves are found in the form of permafrost, as shown by various generations of rock

  13. Geomorphologic mapping in the Ny Ålesund area (Svalbard Island, Norway) for the analysis of geomorphologic effects on rock slopes induced by glacier retreat in climate sensitive High Arctic regions (United States)

    Miccadei, Enrico; Piacentini, Tommaso; Casacchia, Ruggero; Sparapani, Roberto


    The geomorphological effects of glacial retreat, rapidly changing Arctic environments and consequent local temporary permafrost melting are several types of glacial and periglacial landforms (pingos, solifluction, drumlins, etc.) but also debris and rock falls, alluvial fan and glacial outwash development and scarp/slopes retreat and evolution. In this work we have realized a geomorphologic map of rockfalls, landslides, alluvial fans and the slopes and scarps of steep mountainsides in the Ny Ålesund area (Svalbard Island, Norway) focused on the analysis of rock falls as geomorphological effects of glacier retreat, permafrost degradation and higher temperatures on slope processes. The investigation is based on geological and geomorphological field survey, and remote sensing and aerial photo interpretation, The Ny Ålesund area landscape is characterized by rugged non-vegetated mountains only partially covered by glaciers, with steep flanks and rock scarps; the scarps are formed by different types of rocks (intrusive and effusive igneous rocks, marine sedimentary rocks); this landscape is highly affected by debris and rock falls (from scarps and slopes) forming wide talus slopes and by alluvial fan and fluvial outwash (from glaciers), which make the surface sedimentary cover of the island together with rock glaciers and moraine deposits and locally fluvial deposits. The work is focused on the comprehension of the role of different factors in inducing rock falls, alluvial fans, slope/scarps evolution in high geomorphological sensitivity environments (i.e. glacial, periglacial or mountain) including: orography, lithology, rock fracturation, morphostructural setting, meteorological context. The conclusions focus on the possible geomorphological hazards affecting the Ny Ålesund area.

  14. Investigating sediment budgets and pathways using LiDAR DEMs of difference and a geomorphological map (United States)

    Hilger, Ludwig; Becht, Michael; Heckmann, Tobias


    In alpine catchments sediment is moved from one landform to another as long as they are coupled by the activity of geomorphic processes. The spatial and functional interaction of these processes forms sediment cascades reaching from sediment sources or stores to sediment sinks, and ultimately to the catchment outlet. In study presented here, multitemporal high-resolution LiDAR datasets are used to establish morphological sediment budgets. These can be calculated on the raster cell scale, i.e. by differencing digital elevation models (DEM), and on the landform scale, by establishing the net balance of eroded and accumulated material; in the latter case, the spatial unit is a polygon identifying a particular landform on a detailed geomorphological map. The flow of mobilised sediment can be estimated on a DEM using a variety of flow routing algorithms, and the net balance (sediment eroded - sediment deposited) is accumulated along specific pathways. The results of landform-based sediment budgets can be used to validate the flow routing algorithms and to assess functional connectivity between landforms that are arranged along a toposequence. Graph theory is used to store and investigate resulting sediment pathways on different aggregation levels. The incorporation of the geomorphological map highlights potential advantages of object-based over pixel-based approaches to generating graph nodes and analysing sediment cascades.

  15. Shifting paradigms in geomorphology: the fate of research ideas in an educational context (United States)

    Orme, Antony R.


    The acceptance of new ideas into the mainstream of geomorphological education is illustrated from the development of theories dealing with Earth history, glaciation, uniform flow, mass movement, continental mobility, cyclic erosion, and drainage networks. The lag between the conception of new ideas and their incorporation into mainstream texts has varied from negligible to more than 200 years. On one hand, despite its then untestable assumptions, the Davisian cycle of erosion gained rapid favor as the dominant paradigm of the early 20th century before it was found wanting. In contrast, concepts of uniform flow and slope stability, confirmed in the 18th century, waited almost 200 years for incorporation into geomorphology texts sensu stricto, although they had long been available in books on hydraulics and soil mechanics. Continental mobilism had a wild ride, culminating in the eventual acceptance of the plate-tectonics paradigm in the later 20th century. Explanations for the fate of these and other ideas are varied. New ideas are often opposed by establishment conservatism, language barriers, the perceived surrealism of new concepts, and simple ignorance. In contrast, new ideas may be accepted, sooner or later, by virtue of simplicity, forceful and well-connected leadership, or the death of opponents. Although mitigated by the information revolution of recent decades, these forces still persist and influence the extension of new ideas into a larger arena.

  16. Geomorphology and dynamics of supraglacial debris covers in the Western Alps (United States)

    Deline, P.; Gardent, M.; Kirkbride, M. P.; Le Roy, M.; Martin, B.


    In the alpine regions of France and NW Italy, many glaciers of a variety of sizes are at least partly debris-covered, but these have received less scientific research than clean glaciers. During the present period of glacier shrinkage - the area of glacier cover in France has reduced by 26% over the last 40 years -, growing debris cover needs to be understood as an influence on continuing retreat, with consequences for natural hazards, water resources and tourism. We present the results of a combined ongoing study of an inventory of debris-covered glaciers in France with site-specific studies of c. 12 glaciers of contrasting types, in order to understand spatial and temporal changes in supraglacial debris cover. Our specific aims are: 1. To understand the geomorphology of debris-covers and their formation, investigating the types of debris cover in relation to formative processes including extraglacial supply and development during transport. 2. To document the changing extents of supraglacial debris covers, using historical documents and aerial photographs. 3. To interpret areal changes in terms of glaciological and topographical controls on different glacier and debris cover types (catchment morphology, glacier structure, mass balance history, and rock wall collapse magnitude and frequency). 4. To understand the effect of debris cover on glacier dynamics and geomorphological evolution, related to insulation-related modifications to AAR, long profiles, and length changes on both short and long timescales. This includes investigation of the characteristics of debris-covered glacier depositional systems resulting from their modified dynamics.

  17. The Verdesca landslide in the Agri Valley (Basilicata, southern Italy): a new geological and geomorphological framework (United States)

    Gueguen, E.; Bentivenga, M.; Colaiacovo, R.; Margiotta, S.; Summa, V.; Adurno, I.


    A landslide, to the west of Montemurro (a small village in southern Italy), has recently caused damage to buildings and other infrastructure in an urbanized area; as a result the development of new economic activities has been prohibited. The landslide phenomenon started in the last century and has been studied since the 1990s using classical geotechnical methods; however the sliding body continues to move. This paper presents the results of a study carried out using field surveys, geognostic investigations and TDR (time domain reflectometry) measurements in order to reconstruct the stratigraphy of the sediments involved and to further understand the geological and geomorphological context of the slope. This study is part of a larger multidisciplinary project, the results of which will also be presented in this paper. The landslide (rotational slide in the upper sector, developing into a translational slide in the lower part) affects Quaternary continental clastic deposits resting on a bedrock formed by Tertiary siliciclastic sediments of the Gorgoglione Flysch. TDR measurements did not show any significant movement during the period monitored (January 2013-January 2014). Slip zone geometries were hypothesized using inclinometric measurements taken from previous studies, stratigraphic data and geomorphological interpretations of topographic scarps. Feedback from monitoring will confirm this hypothesis.

  18. Competition among marsh macrophytes by means of geomorphological displacement in the intertidal zone (United States)

    Morris, James T.


    Competitive interactions among marsh plant species are mediated by the influence of the vegetation on sediment accretion and modifications of the relative elevation of the marsh surface. A model described here demonstrates some of the feedbacks between physical processes like sediment accretion and biological processes such as those that determine species zonation patterns. Changes in geomorphology, primary productivity and the spatial distribution of plant species are explained by competitive interactions and by interactions among the tides, biomass density, and sediment accretion that regulate the elevation of intertidal wetlands toward an equilibrium with mean sea level (MSL). This equilibrium is affected positively (relative elevation of the marsh surface increases) by the biomass density of emergent, salt marsh macrophytes and negatively by the rate of sea-level rise (SLR). It was demonstrated that a dominant, invading species is able to modify its environment, raising the elevation of the habitat, to exclude competitively inferior species, a process I refer to as geomorphological displacement. However, the outcome depends on a number of variables including the rate of sea-level rise and the distributions of the species across the intertidal gradient. The model predicts that a marsh will evolve toward alternative stable states, depending on the rate of sea-level rise and the species' fundamental and realized distributions within the intertidal zone.

  19. The Vie Cave Geomorphological Site in Southern Tuscany (Italy: Problems of Decay and Conservation

    Directory of Open Access Journals (Sweden)

    Elena Pecchioni


    Full Text Available The Vie Cave are a suggestive network of roads deeply entrenched in the rock, dating back to the Etruscan civilization; these ancient roads connect various settlements and necropolises existing mainly in the area of Sovana, Sorano and Pitigliano towns (Southern Tuscany, Italy. The Vie Cave are located in a peculiar geomorphological site, characterized by the presence of extensive pyroclastic deposits, which have been incised by a parallel network of deep gorges. In this paper, the geomorphological, geological and lithological setting of the Vie Cave area, where several Etruscan archaeological sites are found, are described. The precarious stability of the Vie Cave walls and the several archaeological structures carved into them, the high grade of decay shown by the constituent materials, together with the dense vegetation that has developed over the rocky scarps, are taken into account with the aim to provide a complete assessment of the conditions in which the site lies. Finally, we propose some targeted actions related to the preservation of this territory, showing so distinctive morphology, in order to protect the area from further decay to which it would be subjected if it remained abandoned.

  20. Quantifying Precipitation Variability on Titan Using a GCM and Implications for Observed Geomorphology (United States)

    Faulk, Sean P.; Mitchell, Jonathan L.; Moon, Seulgi; Lora, Juan Manuel


    Titan's zonal-mean precipitation behavior has been widely investigated using general circulation models (GCMs), but the spatial and temporal variability of rainfall in Titan's active hydrologic cycle is less well understood. We conduct statistical analyses of rainfall, diagnosed from GCM simulations of Titan's atmosphere, to determine storm intensity and frequency. Intense storms of methane have been proposed to be critical for enabling mechanical erosion of Titan's surface, as indicated by observations of dendritic valley networks. Using precipitation outputs from the Titan Atmospheric Model (TAM), a GCM shown to realistically simulate many features of Titan's atmosphere, we quantify the precipitation variability within eight separate latitude bins for a variety of initial surface liquid distributions. We find that while the overall wettest regions are indeed the poles, the most intense rainfall generally occurs in the high mid-latitudes, between 45-67.5 degrees, consistent with recent geomorphological observations of alluvial fans concentrated at those latitudes. We also find that precipitation rates necessary for surface erosion, as estimated by Perron et al. (2006) J. Geophys. Res. 111, E11001, frequently occur at all latitudes, with recurrence intervals of less than one Titan year. Such analysis is crucial towards understanding the complex interaction between Titan's atmosphere and surface and defining the influence of precipitation on observed geomorphology.

  1. Structure and contents of layered classification system of digital geomorphology for China

    Institute of Scientific and Technical Information of China (English)

    CHENG Weiming; ZHOU Chenghu; LI Bingyuan; SHEN Yuancun; ZHANG Baiping


    This paper presents the structure and contents of a standardized layered classification system of digital geomorphology for China.This digital classification method combines landforms characteristics of morphology with genesis.A total of 15 categories of exogenic and endogenic forces are divided into two broad categories:morpho-genetic and morpho-structural landforms.Polygon patches are used to manage the morpho-genetic types,and solitary points,lines and polygons are used to manage the morpho-structural types.The classification method of digital morpho-genetic types can be divided into seven layers,i.e.basic morphology and altitude,genesis,sub-genesis,morphology,micro-morphology,slope and aspect,material and lithology.The method proposes combinations of matrix forms based on layered indicators.The attributes of every landform types are obtained from all or some of the seven layers.For the 15 forces categories,some classification indicators and calculation methods are presented for the basic morphology,the morphologic and sub-morphologic landforms of the morpho-genetic types.The solitary polygon,linear and point types of morpho-structural landforms are presented respectively.The layered classification method can meet the demands of scale-span geomorphologic mapping for the national primary scales from 1:500,000 to 1:1,000,000.The layers serve as classification indicators,and therefore can be added and reduced according to mapping demands,providing flexible expandability.

  2. Geomorphological and sedimentological record of accelerated deglaciation of small mountain glacier, Ragnarbreen, Svalbard (United States)

    Ewertowski, Marek


    Most of the Svalbrad glaciers have been in retreat since the end of the Little Ice Age (LIA). Hence, they give a good opportunity to study the geomorphological and sedimentological record of deglaciation. The aim of the study is to describe main landsystem elements of Ragnar glacier and relate them to different stages of the glacier recession. The Ragnar glacier is located in the Svalbard archipelago, in the central part of the West Spitsbergen Isle, in the north branch of Billefjorden. Ragnar is a small (~ 6 km2), outlet glacier, which current clean ice edge has retreated ca. 1500 m from the position related to the maximum LIA extent. Fieldworks of the study comprised detailed geomorphological mapping and sedimentary works. Four main elements of the landsystem of the Ragnar glacier can be distinguished: 1) Clean glacier surface. Currently, the ice surface of Ragnar glacier is almost completely debris-free and with only several supraglacial streams. 2) Ice-marginal lake. The lake started to form after 1980 year. Since that time, its length has reached 1000 m. Distant (from the ice-edge) part of the lake is shallow (changes in distribution of the sediments and landforms. They also add some premises that in the first stage of deglaciation debris flow and other mass wasting processes are most common. In the later phase glaciolacustrine and glaciofluvial deposition also plays important role in transformation of landforms and sediments.

  3. Examining the Effects of Geomorphology on Hydrologic Transit Times Using Liquid Water Isotopes (United States)

    Delgado, D.; Troch, P.; Lyon, S.; Desilets, S.; Guardiola, M.; Broxton, P.


    In recent years there has been resurgence in improving physically based and spatially distributed hydrological response models. However there continues to be many obstacles in accurately representing the basic processes governing rainfall runoff responses. Much of these inaccuracies can be attributed to such problems as a lack of understanding in runoff processes, unknown heterogeneity both at the surface and subsurface, variations in driving forces and the effects of geomorphology on the transformation of rainfall to stream flow. We hope to improve on such ambiguity is by examining the relationships between geomorphology and hydrology through the investigation of transit time distributions, which can be used as a fundamental descriptor of catchments" characteristics such as storage and flow pathways. By examining stable isotopic variability in precipitation, soil moisture and stream flow to determine transit times, we hope to better understand the effects of topographic land structures on the hydrologic response system. The first step in this process has been to fully instrument a series of hill slopes with similar structural and pedologic characteristics, located in the Marshall Gulch region of the Santa Catalina Mountains. Equipment including suction and non- suction lysimeters, tipping bucket rain gauges and automatic flow samplers with data loggers positioned to take stream flow and precipitation samples have been used to collect samples throughout the region. A description of preliminary results will be presented.

  4. Volcanic geomorphology of Tambora (Sumbawa island, Indonesia) on the basis of SRTM DEM data (United States)

    Favalli, Massimiliano; Karátson, David; Gertisser, Ralf; Fornaciai, Alessandro


    Tambora volcano (ca. 2700 m a.s.l.), famous for its great 1815 eruption, is located at the western tip of Sanggar Peninsula, Sumbawa. It is characterized by trachybasalts, trachyandesites and tephriphonolites that build up a 30 x 40 km and >1000 km3 large shield-like volcano (Self et al. 1984), inferred to be up to 4,300 m high prior to 1815. The volcano was truncated during the 1815 eruption by a 6 x 7 km wide, 1.2 km deep caldera, revealing pre-eruptive units in the caldera walls (e.g. 1-5 ka tuff layers and cut by a number of prominent valleys sometime with a lobed pattern. These are indicated (but not analysed) in Self et al. (1984) as faults; other features such as old sector collapses and amphitheater-valley dissection can also be envisaged. The other, younger, sligthly dissected flanks of the volcano are dotted by some twenty parasitic cones. References: Favalli, M., Karatson, D., Yepes, J. & Nannipieri, L. (2014). Surface fitting in geomorphology - Examples for regular-shaped volcanic landforms. Geomorphology, 221, 139-149. Self, S., Rampino, M.R., Newton, M.S. & Wolff, J.A. (1984). Volcanological study of the great Tambora eruption of 1815. Geology, v.12, pp.659-663.

  5. Using Remote Sensing, Geomorphology, and Soils to Map Episodic Streams in Drylands (United States)

    Thibodeaux-Yost, S. N. S.


    Millions of acres of public land in the California deserts are currently being evaluated and permitted for the construction of large-scale renewable energy projects. The absence of a standard method for identifying episodic streams in arid and semi-arid (dryland) regions is a source of conflict between project developers and the government agencies responsible for conserving natural resources and permitting renewable energy projects. There is a need for a consistent, efficient, and cost-effective dryland stream delineation protocol that accurately reflects the extent and distribution of active watercourses. This thesis evaluates the stream delineation method and results used by the developer for the proposed Ridgecrest Solar Power Project on the El Paso Fan, Ridgecrest, Kern County, California. This evaluation is then compared and contrasted with results achieved using remote sensing, geomorphology, soils, and GIS analysis to identify stream presence on the site. This study's results identified 105 acres of watercourse, a value 10 times greater than that originally identified by the project developer. In addition, the applied methods provide an ecohydrologic base map to better inform project siting and potential project impact mitigation opportunities. This study concludes that remote sensing, geomorphology, and dryland soils can be used to accurately and efficiently identify episodic stream activity and the extent of watercourses in dryland environments.

  6. A Method for Applying Fluvial Geomorphology in Support of Catchment-Scale River Restoration Planning (United States)

    Sear, D.; Newson, M.; Hill, C.; Branson, J.; Old, J.


    Fluvial geomorphology is increasingly used by those responsible for conserving river ecosystems; survey techniques are used to derive conceptual models of the processes and forms that characterise particular systems and locations, with a view to making statements of `condition' or `status' and providing fundamental strategies for rehabilitation/restoration. However, there are important scale-related problems in developing catchments scale restoration plans that inevitably are implemented on a reach- by-reach basis. This paper reports on a watershed scale methodology for setting geomorphological and physical habitat reference conditions based on a science-based conceptual model of cachment:channel function. Using a case study from the River Nar, a gravel-bed groundwater dominated river in the UK with important conservation status, the paper describes the sequences of the methodology; from analysis of available evidence, process of field data capture and development of a conceptual model of catchment-wide fluvial dynamics. Reference conditions were derived from the conceptual model and gathered from the literature for the two main river types found on the river Nar, and compared with the current situation in 76 sub-reaches from source to mouth. Multi-Criteria Analysis (MCA) was used to score the extent of channel departures from `natural' and to suggest the basis for a progressive restoration strategy for the whole river system. MCA is shown to be a flexible method for setting and communicating decisions that are amenable to stakeholder and public consultation.

  7. Detailed Geomorphological survey in a recently deglaciated area by Terrestrial Laser Scanner (United States)

    Rocha Francelino, Marcio; Schünemann, Adriano Luis; Gonçalves Reynaud Schaefer, Carlos Ernesto; Inacio Fernandes Filho, Elpidio; Araujo Almeida, Pedro Henrique; Thomazini, Andre


    High resolution topographic surveys are important tools to model landscapes, especially in zones subjected to strong environmental changes, such as Antarctica, where landforms are highly influenced by glacial retreat and permafrost melting. The aim of this work was to map geomorphological features in Keller Peninsula, King George Island, Maritime Antarctica, by using Terrestrial Laser Scanner. The survey was performed in 2014/2015 and 2015/2016 during the austral summer, by means of a Terrestrial Laser Scanner (TLS) model VZ-1000 of Rigel. In order to cover the entire Peninsula, the TLS equipment was installed in 81 different points. After processing, a cloud with more than 5 million points was generated, spatially well distributed, enabling the generalization process to obtain surface models with high performance. Hence, ultra-details of the different landscape features on the peninsula were studied. Results obtained were compared with a geomorphological map previously produced from the analysis of aerial photographs in the same area. Different limits were observed between the two techniques, mostly regarding sizes, allowing the identification of new landscape features. Depositional features are the most common landforms in Keller Peninsula, encompassing scree slopes, protalus, morainas and talus. Rock outcrops are common, forming prominent scarpments, feeding talus and protalus. Small patterned-ground soil areas were distinguished by the TLS. The use of TLS allowed the mapping of landforms with high resolution needed for environmental monitoring.

  8. What numerical models can and cannot tell us: Limitations on inferences in computational geomorphology (United States)

    Van De Wiel, Marco


    Computer simulations and numerical experiments have become an increasingly important part of geomorphological investigation in the last decades. Process-based numerical models attempt to simulate real-world processes in a virtual environment which can be easily manipulated and studied. Conceptually, the experimental design of these simulation studies broadly falls in one of three categories: predictive modelling, explanatory modelling, and exploratory modelling. However, the epistemologies of these three modes of modelling are as of yet incomplete and not fully understood. Not only do the three modes of modelling have different underlying assumptions, they also have different criteria to establish validity and different limitations on the interpretations and inferences that can be made. These differences are usually only implicitly recognized, if at all, in computational geomorphology studies. This presentation provides an explicit, though not necessarily exhaustive, overview of the epistemological differences between the three modes of computational modelling, and of the limitations this imposes on what can and cannot be learned from simulation experiments.

  9. Estimation of sediment yield during storms based on soil and watershed geomorphology characteristics (United States)

    Lee, Kwan Tun; Yang, Chi-Cheng


    SummaryConcentrated rainfall usually results in serious soil erosion on steep hillslopes. Since the itinerary of the eroded sediment is complicated, estimating watershed erosion during storms is practically difficult. A physically-based approach for sediment yield estimation during storms was proposed in this study. By using soil and watershed geomorphologic information, analytical solutions for sediment travel time in different orders of overland areas and channels were derived to develop a geomorphologic instantaneous unit sedimentgraph (GIUS) which showed the temporal distribution of sediment discharge resulting from an instantaneous rainfall excess input. The resultant GIUS was a function of the rainfall excess intensity and sediment delivery ratio. The linearity restriction of the unit hydrograph theory was relaxed. Sediment yields during storm events were calculated by convoluting rainfall intensities with the proposed GIUS, which had been verified by using data from the Goodwin Creek Experimental Watershed in Mississippi, the United States. The simulated and the measured sediment yields were in good agreement for the test storms. Sensitivity of the sedimentgraph to the model parameters was also investigated. The proposed model was considered a promising application for sediment yield estimation in the field of water resources design.

  10. Estimating for Sediment Yield During Storm Based on Soil and Watershed Geomorphology Characteristics (United States)

    Lee, K.; Yang, C.


    Concentrated rainfall usually results in serious soil erosion on steep hillslopes. Since the itinerary of the eroded sediment is complicated and measure for temporal sediment concentration is a laborious work, estimating for watershed erosion during storm is considered as difficulty in practice. In this study, a simple method for estimating sediment yield during storm was derived. By using soil data and watershed geomorphologic information, analytical solutions for sediment travel times and delivery ratios for different orders of overland areas and channels were derived to form an instantaneous unit sedimentgraph. Consequently, sediment yield during storm can be estimated by convoluting the rainfall intensities with the proposed instantaneous unit sedimentgraph. In this study, the proposed model has been verified using the data from Goodwin Experimental Watershed located in Mississippi of the United States. A digital elevation model was adopted to obtain the watershed geomorphologic factors for subsequent runoff routing and sediment concentration estimations. The simulated and the measured sediment yields were in good agreement for the test storms. It is therefore promising for the proposed model to be used for sediment yield estimation in gauged and ungauged watersheds for water resources design work.

  11. Natural hazard management high education: laboratory of hydrologic and hydraulic risk management and applied geomorphology (United States)

    Giosa, L.; Margiotta, M. R.; Sdao, F.; Sole, A.; Albano, R.; Cappa, G.; Giammatteo, C.; Pagliuca, R.; Piccolo, G.; Statuto, D.


    The Environmental Engineering Faculty of University of Basilicata have higher-level course for students in the field of natural hazard. The curriculum provides expertise in the field of prediction, prevention and management of earthquake risk, hydrologic-hydraulic risk, and geomorphological risk. These skills will contribute to the training of specialists, as well as having a thorough knowledge of the genesis and the phenomenology of natural risks, know how to interpret, evaluate and monitor the dynamic of environment and of territory. In addition to basic training in the fields of mathematics and physics, the course of study provides specific lessons relating to seismic and structural dynamics of land, environmental and computational hydraulics, hydrology and applied hydrogeology. In particular in this course there are organized two connected examination arguments: Laboratory of hydrologic and hydraulic risk management and Applied geomorphology. These course foresee the development and resolution of natural hazard problems through the study of a real natural disaster. In the last year, the work project has regarded the collapse of two decantation basins of fluorspar, extracted from some mines in Stava Valley, 19 July 1985, northern Italy. During the development of the course, data and event information has been collected, a guided tour to the places of the disaster has been organized, and finally the application of mathematical models to simulate the disaster and analysis of the results has been carried out. The student work has been presented in a public workshop.

  12. Hydro-geomorphologic events in Portugal and its association with Circulation weather types (United States)

    Pereira, Susana; Ramos, Alexandre M.; Rebelo, Luís; Trigo, Ricardo M.; Zêzere, José L.


    Floods and landslides correspond to the most hazardous weather driven natural disasters in Portugal. A recent improvement on their characterization has been achieved with the gathering of basic information on past floods and landslides that caused social consequences in Portugal for the period 1865-2015 through the DISASTER database (Zêzere et al., 2014). This database was built under the assumption that strong social impacts of floods and landslides are sufficient relevant to be reported consistently by national and regional newspapers. The DISASTER database contains detailed information on the location, date of occurrence and social impacts (fatalities, injuries, missing people, evacuated and homeless people) of each individual hydro-geomorphologic case (1677 flood cases and 292 landslide cases). These hydro-geomorphologic disaster cases are grouped in a restrict number of DISASTER events that were selected according to the following criteria: a set of at least 3 DISASTER cases sharing the same trigger in time (with no more than 3 days without cases), which have a widespread spatial extension related to the triggering mechanism and a certain magnitude. In total, the DISASTER database includes 134 events (3.7 average days of duration) that generated high social impacts in Portugal (962 fatalities and 40878 homeless people). Each DISASTER event was characterized with the following attributes: hydro-geomorphologic event type (e.g landslides, floods, flash floods, urban floods); date of occurrence (year, month and days); duration in days; spatial location in GIS; number of fatalities, injured, evacuated and homeless people; and weather type responsible for triggering the event. The atmospheric forcing at different time scales is the main trigger for the hydro-meteorological DISASTER events occurred in Portugal. In this regard there is an urge for a more systematic assessment of the weather types associated to flood and landslide damaging events to correctly

  13. Holocene relative sea level variations at the spit system Feddet (Denmark) resolved by ground-penetrating radar and geomorphological data

    DEFF Research Database (Denmark)

    Hede, Mikkel Ulfeldt; Bendixen, Mette; Clemmensen, Lars B;

    Estimates of Holocene sea-level variations have been presented in a range of studies based on different approaches, including interpretation of internal beach ridge characteristics from ground-penetrating radar (GPR) and geomorphological data. We present GPR data and geomorphological observations...... of sea level variation and vertical land movement in southern Scandinavia in response to unloading after the last glaciation. We have tested the validity of downlap points, which marks the transition from beach to upper shoreface as sea-level markers. The test is based on comparative analyses...

  14. Evaluation of a geomorphology-based conceptual IUH in a mountain watershed (United States)

    López, J. J.; Gimena, F. N.; Giráldez, J. V.; Ayuso, J. L.; Goñi, M.


    Hydrograph generation at a point in the drainage network, as a watershed response to a rainfall event, is a complex process that depends on watershed and storm characteristics. Among the available methods for hydrologic design, the unit hydrograph (UH) is one of those most widely used. It is a conceptual model which assumes the linear systems theory and incorporates the rainfall characteristics in the simulation process. There is, obviously, a close relationship between the geomorphologic characteristics of a watershed and its hydrologic response. During the past years hydrologists and geomorphologists have worked together in a joint effort to characterize the global average watershed response as a function of its geomorphologic properties. Since Rodríguez-Iturbe and Valdés presented the Geomorphological Instantaneous Unit Hydrograph (GIUH) there have been many attempts to propose an Instantaneous Unit Hydrograph (IUH) that incorporates the geomorphological properties of the watershed. Also, linear reservoir models were, and are still, very frequently used for simulating rainfall-runoff processes and, more precisely, for determining the unit hydrograph of a watershed. The fundamental aim of this work is to present and evaluate an Instantaneous Unit Hydrograph based on a cascade of linear Reservoirs obtained by taking the Geomorphology of the watershed (IUHGR). The geomorphological association of reservoirs in this IUH is characterized by means of the sub-basins into which the watershed is divided starting from the drainage network. The formulation of this IUH, obtained from the one set up by López et al.,(2005), has been carried out both for the case of the spatial uniformity of the sub-basins and for that of considering their spatial variability. Also, this model's evaluation was made based on a detailed analysis of it and on a comparative study. For the latter, some IUHs with some similar characteristics to the one proposed and which were sufficiently vouched

  15. Catchment controls and human disturbances on the geomorphology of small Mediterranean estuarine systems (United States)

    Estrany, Joan; Grimalt, Miquel


    Geographic signatures are physical and human-induced characteristics or processes that identify comparable or unique features of estuaries along latitudinal gradients. In Mediterranean areas, the microtidal regime and the strong seasonal and inter-annual contrasts cause an alternation between relatively high runoff and arid conditions. Furthermore, the long history of human settlement also increases the complexity in the study of these estuarine systems. This study investigates these signatures of the estuaries located within the Mallorcan eastern coast, which are geomorphologically homogeneous because of a similar bedrock geology and Holocene history. A multi-method approach focused on the integration of geomorphometry, hydraulics, historical sources and statistics was used. We explore the role played by catchment morphometric parameters, severe flash flood events and human disturbances in controlling the geomorphology of 10 beach-barrier enclosed, fluvial incised lagoons. Most of the lagoons discharge into 'calas', ranging in size from 1345 to 17,537 m2 and their related catchments are representative of the Mediterranean hydrological systems. Multiple regression models illustrate that the size, slope and drainage network development of the catchments explain the variance in length (r2 = 0.67), volume (r2 = 0.49), area (r2 = 0.64), circularity (r2 = 0.72) and average width (r2 = 0.81) of the lagoons. Depending on these catchment morphometric variables, the shape of the lagoons is also determined by the occurrence of catastrophic flash floods, which cause scouring and dredging, whereas the ordinary flood events and sea storms promote refilling and sedimentation. A historical analysis since 1850 documented 18 flood events, 5 of which were catastrophic with destructive effects along the catchments and large morphological changes in coastal lagoons. High intensity rainfall (up to 200 mm in 2 h), the geomorphometry of the catchments and the massive construction of

  16. Long- to short-term denudation rates in the southern Apennines: geomorphological markers and chronological constraints (United States)

    Gioia, Dario; Martino, Claudio; Schiattarella, Marcello


    Age constraints of geomorphological markers and consequent estimates of long- to short-term denudation rates from southern Italy are given here. Geomorphic analysis of the valley of the Tanagro River combined with apatite fission track data and radiometric dating provided useful information on the ages and evolution of some significant morphotectonic markers such as regional planated landscapes, erosional land surfaces and fluvial terraces. Reconstruction of paleotopography and estimation of the eroded volumes were perfomed starting from the plano-altimetric distribution of several orders of erosional land surfaces surveyed in the study area. Additional data about denudation rates related to the recent and/or active geomorphological system have been obtained by estimating the amount of suspended sediment yield at the outlet of some catchments using empirical relationships based on the hierarchical arrangement of the drainage network. Denudation rates obtained through these methods have been compared with the sedimentation rates calculated for two adjacent basins (the Pantano di San Gregorio and the Vallo di Diano), on the basis of published tephrochronological constraints. These rates have also been compared with those calculated for the historical sediment accumulation in a small catchment located to the north of the study area, with long-term exhumation data from thermochronometry, and with uplift rates from the study area. Long- and short-term denudation rates are included between 0.1 and 0.2 mm/yr, in good agreement with regional data and long-term sedimentation rates from the Vallo di Diano and the Pantano di San Gregorio Magno basins. On the other hand, higher values of exhumation rates from thermochronometry suggest the existence of past erosional processes faster than the recent and present-day exogenic dismantling. Finally, the comparison between uplift and denudation rates indicates that the fluvial erosion did not match the tectonic uplift during the

  17. The geomorphological effect of cornice fall avalanches in the Longyeardalen valley, Svalbard (United States)

    Eckerstorfer, M.; Christiansen, H. H.; Rubensdotter, L.; Vogel, S.


    The study of snow avalanches and their geomorphological effect in the periglacial parts of the cryosphere is important for enhanced geomorphological process understanding as well as hazard-related studies. Only a few field studies, and particularly few in the High Arctic, have quantified avalanche sedimentation. Snow avalanches are traditionally ranked behind rockfall in terms of their significance for mass-wasting processes of rockslopes. Cornice fall avalanches are at present the most dominant snow avalanche type at two slope systems, called Nybyen and Larsbreen, in the valley Longyeardalen in central Svalbard. Both slope systems are on northwest-facing lee slopes underneath a large summit plateau, with annual cornices forming on the top. High-frequency and magnitude cornice fall avalanching is observed by daily automatic time-lapse photography. In addition, rock debris sedimentation by cornice fall avalanches was measured directly in permanent sediment traps or by snow inventories. The results from a maximum of seven years of measurements in a total of 13 catchments show maximum mean rock debris sedimentation rates ranging from 8.2 to 38.7 kg m-2 at Nybyen, and from 0.8 to 55.4 kg m-2 at Larsbreen. Correspondingly, avalanche fan surfaces accreted from 2.6 to 8.8 mm yr-1 at Nybyen, and from 0.2 to 13.9 mm yr-1 at Larsbreen. This comparably efficient rockslope mass wasting is due to collapsing cornices producing cornice fall avalanches containing large amounts of rock debris throughout the entire winter. The rock debris of different origin stems from the plateau crests, the adjacent free rock face and the transport pathway, accumulating distinct avalanche fans at both slope systems. Cornice fall avalanche sedimentation also contributed to the development of a rock glacier at the Larsbreen site during the Holocene. We have recorded present maximum rockwall retreat rates of 0.9 mm yr-1 at Nybyen, but as much as 6.7 mm yr-1 at Larsbreen, while average Holocene

  18. Eco-geomorphological Response of an Estuarine Wetland to Changes in the Hydraulic Regime (United States)

    Howe, A.; Rodrí Guez, J.


    In the Hunter Estuary, NSW, Australia, tidal regimes of numerous wetlands have been affected by extensive anthropomorphic intervention, including harbour dredging, land reclamation, and construction of infrastructure. The importance of these wetlands to ecosystem services such as primary productivity, flood attenuation and water quality enhancement has led to an increased effort to rehabilitate degraded sites by reintroduction of tidal flows. Because of the complex and dynamics interactions among hydraulic regime, vegetation and geomorphology, it is difficult to predict how wetlands will respond to the reintroduction of these flows and whether the resulting habitat distribution will achieve desired management outcomes. Eco-geomorphology research conducted at a rehabilitated wetland comprised of mangrove forest and saltmarsh has tracked the response of estuarine vegetation distribution and wetland geomorphology to reinstatement of tidal flows following removal of impediments in 1995. The wetland is an important site for migratory shorebirds and is highly compartmentalized due to the presence of roads and culverts. Our research methodology integrates historical analysis, field measurements and laboratory experiments. Historical analysis matched vegetation evolution obtained from aerial photography to bird roosting habitat use, which is in decline. Field data collection carried out in the last two years included topographic, vegetation and soil surveys; velocity, water quality and water level profiling; and high precision measurements of substrate shallow subsidence and vertical accretion. Laboratory studies focussed on the effects of estuarine vegetation on flow resistance. All this information has allowed for the characterization and conceptualization of the system, which includes zones with different tidal attenuation levels and vegetation distribution. It was found that an increased tidal frame resulting from hydraulic manipulation lead to a landward shift in

  19. The geomorphological effect of cornice fall avalanches in the Longyeardalen valley, Svalbard

    Directory of Open Access Journals (Sweden)

    M. Eckerstorfer


    Full Text Available The study of snow avalanches and their geomorphological effect in the periglacial parts of the cryosphere is important for enhanced geomorphological process understanding as well as hazard-related studies. Only a few field studies, and particularly few in the High Arctic, have quantified avalanche sedimentation. Snow avalanches are traditionally ranked behind rockfall in terms of their significance for mass-wasting processes of rockslopes. Cornice fall avalanches are at present the most dominant snow avalanche type at two slope systems, called Nybyen and Larsbreen, in the valley Longyeardalen in central Svalbard. Both slope systems are on northwest-facing lee slopes underneath a large summit plateau, with annual cornices forming on the top. High-frequency and magnitude cornice fall avalanching is observed by daily automatic time-lapse photography. In addition, rock debris sedimentation by cornice fall avalanches was measured directly in permanent sediment traps or by snow inventories. The results from a maximum of seven years of measurements in a total of 13 catchments show maximum mean rock debris sedimentation rates ranging from 8.2 to 38.7 kg m−2 at Nybyen, and from 0.8 to 55.4 kg m−2 at Larsbreen. Correspondingly, avalanche fan surfaces accreted from 2.6 to 8.8 mm yr−1 at Nybyen, and from 0.2 to 13.9 mm yr−1 at Larsbreen. This comparably efficient rockslope mass wasting is due to collapsing cornices producing cornice fall avalanches containing large amounts of rock debris throughout the entire winter. The rock debris of different origin stems from the plateau crests, the adjacent free rock face and the transport pathway, accumulating distinct avalanche fans at both slope systems. Cornice fall avalanche sedimentation also contributed to the development of a rock glacier at the Larsbreen site during the Holocene. We have recorded present maximum rockwall retreat rates of 0.9 mm yr−1 at Nybyen, but as much as 6.7 mm yr−1 at

  20. Glacial geomorphology of the foreland of Nordenskiöldbreen, Svalbard (United States)

    Ewertowski, Marek; Dominiczak, Aleksander; Evans, David; Roberts, David; Tomczyk, Aleksandra


    The Nordenskiöldbreen (78°39'N, 16°55'E) is the only one tidewater glacier in the Billefjorden area, central part of Spitsbergen. Since the end of the Little Ice Age, the glacier margin retreated by 1490 m (north wing) and 3100 m (south wing). Glacier recession exposed complex landform assemblages including moraines, flutes and bedrock expositions. Glacier recession and landforms' development in the terrestrial parts of the foreland were quantified using time-series of orthophotos and digital elevation models (generated based on 1961, 1990, 2009 aerial photographs) and high resolution satellite images from 2013. Additionally, detailed analyses of a case study area were performed based on unmanned aerial vehicle (UAV) imagery (3 cm resolution). A time-series of 1:5,000 geomorphological maps of the whole foreland, together with 1:300 map of a sample area of non-linear flutes and results of sedimentological analysis, enable us to assess the evolution of glacial landform assemblages. The maps reveal outer zone of latero-frontal moraine arcs and inner zone comprising bedrock draped by linear and non-linear flutes. North wing is characterised by a very limited supraglacial debris cover, which allows for exhibition of subglacial till (partly deposited in subaquatic condition). The pattern of landforms, including cross-cutting linear and non-linear flutes, suggests complexity and overlapping of subglacial processes during the glacier advance. The following recession of the glacier with very limited debris cover allows for preservation of the large part of this landform assemblage. Geomorphology of the southern part of the glacier foreland is more complex and, in addition to flutes, comprises areas of ice-cored moraines, small eskers and debris ridges networks, interpreted as infilling of crevasses due to ice hydrofracturing. This can be related to the potential surging activity or blocking of meltwater under a warm-base part of the polythermal glacier by its frozen

  1. Digital geomorphological information for alpine hazard studies using laser altimetry data and GIS: With an example from Vorarlberg, Austria

    NARCIS (Netherlands)

    Seijmonsbergen, H.; Mikoś, M.; Hübel, J.; Koboltschnig, G.


    Detailed geomorphological information has proven beneficial for the spatial recognition and delineation of natural hazards such as rock fall, slides and debris flows in alpine ecosystems. New digital (semi-)automated mapping and availability of LiDAR altimetry data may improve the accessibility and

  2. Regional geomorphology of the continental slope of NW India: Delineation of the signatures of deep-seated structures

    Digital Repository Service at National Institute of Oceanography (India)

    Chauhan, O.S.; Almeida, F.; Moraes, C.

    Geomorphological features (derived from 16,000 lkm of echo-sounding and bathymetric data) and deep-seated tectonic tectonic structures of the continental margin off NW India are presented. The shelf break over the entire region occurs between 80...

  3. The Geoclutter Experiment 2001: Remote acoustic imaging of sub-bottom and seafloor geomorphology in continental shelf waters (United States)

    Makris, Nicholas C.; Ratilal, Purnima; Lai, Yisan; Symonds, Deanelle T.; Ruhlmann, Lilimar A.; Scheer, Edward K.


    In the Geoclutter experiment of April-May 2001, an active sonar system was used to remotely and rapidly image geomorphology over wide areas in continental shelf waters by long-range echo sounding. The bistatic system, deployed in the strataform area south of Long Island, imaged extensive networks of buried river channels and inclined subseafloor strata over tens of kilometers in near real time. Bathymetric relief in the strataform area is extremely benign. The vast majority of features imaged apparently correspond to sub-bottom geomorphology that sound waves reach after tunneling as well as propagating through the overlying sediment. Returns from buried river channels were often found to be as discrete and strong as those from calibrated targets placed in the water column. Since buried river channels are expected to be ubiquitous in continental shelf environments, sub-seafloor geomorphology will play a major role in producing ''false alarms'' or clutter in long-range sonar systems that search for submerged objects such as underwater vehicles or marine mammals. Wave guide scattering and propagation are inherent to this new remote sensing technology because source signals are transmitted over hundreds of water-column depths in range to image sub-seafloor and seafloor geomorphology.

  4. Temporal and spatial evolution of coastline and subaqueous geomorphology in muddy coast of the Yellow River Delta

    Institute of Scientific and Technical Information of China (English)

    PENG Jun; MA Suisui; CHEN Hongquan; LI Zhiwen


    Based on measured data of coastline and bathometry,processed by softwares of Surfer and Mapinfo,and combined with sediment loads in different phases at Lijin gauging station,temporal and spatial evolution of coastline and subaqueous geomorphology in muddy coast of the Yellow River Delta is analyzed.The results show that ~68% of sediments were delivered by the Yellow River deposited around the river mouth and in the littoral area from 1953 to 2000.Coastline in different coasts had distinctive changes in response to shifts of river course.Coastline was stable in the west of the Diaokou river mouth.Coastline from the east of the Diaokou river mouth to the north of the Gudong oilfield had experienced siltation,then serious erosion,and finally kept stable with sea walls conservation.Generally,coastline of the survived river mouth of the Qingshuigou river course stretched seaward,whereas the south side of sand spit at the Qingshuigou old river mouth was eroded after the Yellow River inpouring near the position at the Qing 8.The subaqueous geomorphology off the survived river mouth exhibited siltation from 1976 to 1996,with flat topset beds and steeper foreset beds.From 1996 to 2005,the subaqueous geomorphology off the Qingshuigou old river mouth was eroded in the topset and foreset beds,but silted in the bottomset beds.The subaqueous geomorphology off the new river mouth sequentially performed siltation with small degree compared to that of 1976-1996.

  5. 10 years of aeolian geomorphology at the EGU: past achievements and future challenges (United States)

    Baas, Andreas C. W.; Wiggs, Giles F. S.; Claudin, Philippe


    On this tenth anniversary of the Aeolian Processes & Landforms session at the EGU the original conveners review and reflect on the recent achievements and expansion in aeolian geomorphological research, focussing on advances in our understanding of sand transport processes, dune development and dynamics, and the mechanisms and scalings involved. This talk will highlight the variety and impact of the dramatic increase in the extent and interest of research on aeolian processes and landforms in the last ten years, including the increasingly strong community presence at international meetings, the diversity and extent of collaborations across subject boundaries, and the application of new measurement technologies and mathematical approaches. We conclude with a forward-looking prospectus of exciting future challenges and open research questions.

  6. Three-dimensional coastal geomorphology deformation modelling using differential synthetic aperture interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Marghany, Maged [Universiti Teknologi Malaysia, Skudai, Johor Bahru (Malaysia). Inst. for Science and Technology Geospatial (INSTeG)


    This work presents a new approach for three-dimensional (3D) coastal deformation simulation using differential synthetic aperture interferometry (DInSAR). In doing so, conventional InSAR procedures are implemented to three repeat passes of RADARSAT-1 SAR fine mode data (F1). Further, the DInSAR method is implemented with the phase unwrapping technique. Consequently, DInSAR is used to eliminate the phase decorrelation impact from the interferograms. The study shows the accurate performance of DInSAR with a root mean square error of 0.02 {+-} 0.21 m and 90% confidence intervals. In conclusion, the DInSAR technique produces an accurate 3D coastal geomorphology reconstruction. (orig.)

  7. The influence of control parameter estimation on large scale geomorphological interpretation of pointclouds (United States)

    Dorninger, P.; Koma, Z.; Székely, B.


    In recent years, laser scanning, also referred to as LiDAR, has proved to be an important tool for topographic data acquisition. Basically, laser scanning acquires a more or less homogeneously distributed point cloud. These points represent all natural objects like terrain and vegetation as well as man-made objects such as buildings, streets, powerlines, or other constructions. Due to the enormous amount of data provided by current scanning systems capturing up to several hundred thousands of points per second, the immediate application of such point clouds for large scale interpretation and analysis is often prohibitive due to restrictions of the hard- and software infrastructure. To overcome this, numerous methods for the determination of derived products do exist. Commonly, Digital Terrain Models (DTM) or Digital Surface Models (DSM) are derived to represent the topography using a regular grid as datastructure. The obvious advantages are a significant reduction of the amount of data and the introduction of an implicit neighborhood topology enabling the application of efficient post processing methods. The major disadvantages are the loss of 3D information (i.e. overhangs) as well as the loss of information due to the interpolation approach used. We introduced a segmentation approach enabling the determination of planar structures within a given point cloud. It was originally developed for the purpose of building modeling but has proven to be well suited for large scale geomorphological analysis as well. The result is an assignment of the original points to a set of planes. Each plane is represented by its plane parameters. Additionally, numerous quality and quantity parameters are determined (e.g. aspect, slope, local roughness, etc.). In this contribution, we investigate the influence of the control parameters required for the plane segmentation on the geomorphological interpretation of the derived product. The respective control parameters may be determined

  8. Geomorphologic Study of Anhui Section of Changjiang River Using Landsat TM Image

    Institute of Scientific and Technical Information of China (English)


    Fluvial landforms in the Anhui section of the Changjiang (Yangtze) River are often considered as the main factors for frequent floods. It is these special landforms that influence the channel changes of the Changjiang River.Using Landsat TM image of 2000, this paper conducted a series of image processing, including principal component analysis, multi-spectral composition, gray value statstics, and spectral analysis of ground objects. Then it got a new interpretation map of different kinds of fluvial landforms of the Changjiang River in the Anhui section. Based on the interpretation mentioned above, the paper analyzes the distribution and characteristics of such typical landforms as terraces, floodplains and battures, and their functions on the changes of river channel. The results show a consistence with the earlier conclusion that the Anhui section of the Changjiang River tends to deflect gradually toward south,which provides more implications for further study on the geomorphologic evolution of the river channel.

  9. The "Geomorphologic Diagonal" of Central Europe - towards a new morphotectonic interpretation of macroforms in average mountains (United States)

    Zoeller, Ludwig


    Modern methods of low temperature thermochronology are able to throw light on the geomorphological development of macrorelief landforms. A rarely investigated problem concerns the orientation and morphotectonic evolution of Central European uplands (low to mid-elevation mountain ranges). A conspicuous NW-SE striking boundary takes course through Germany from the Osning and Teutoburg Forest in the NW to the Bavarian Forest in the SE. I call this line the "geomorphological diagonal". East of this line, more or less NW-SE striking morphotectonic features (e.g., Harz Mountains, Sudety) dominate the macrorelief up to the eastern border of Central Europe (Thornquist-Teysseire Lineament), with the exception of the Ohre Rift and Central Bohemia. West of this line, the macrorelief is either characterized by NNE-SSW to N-S oriented structures (e.g., Upper Rhine Rift) and, to a lesser extent, by (S)SW-(E)NE mountain ranges (southern Rhenish Slate Mountains and Ore Mountains) or by no predominance at all. In the Lower Rhine Embayment and along the Middle Rhine River, (N)NW-(S)SE directed morphotectonic features influence the low mountain ranges. In several cases geologists have proven that NW-SE morphotectonic structures are related to the Upper Cretaceous (Santonian to Campanian) "basin inversion" (e.g., von Eynatten et al. 2008). A compilation of low temperature thermochronological data (AFT, [U-Th]/He) from Central Europe clearly supports strong crustal cooling during the Upper Cretaceous and lowermost Tertiary in morphotectonically protruded crustal blocks east of the geomorphological diagonal, whereas west of it the age data available so far exhibit a much larger scatter from Upper Paleozoic to Tertiary without clear evidence of an outstanding Upper Cretaceous crustal cooling event. Based on this data I hypothesize that east of the diagonal macroforms of uplifted denudation surfaces ("peneplains" or "etchplains") may be inherited from the Cretaceous whereas west of it

  10. Geological and geomorphological controls on groundwater occurrence in a hard rock region (United States)

    Rajaveni, S. P.; Brindha, K.; Elango, L.


    Remote sensing and GIS tools have broadly helped hydrogeologists to delineate the groundwater prospective zones for watershed development and management. The origin, movement and existence of groundwater depends on several factors such as slope, drainage density, land use, geology, lineament density and geomorphology. Based on these, the mapping and identification of groundwater potential zones were carried out in a part of Nalgonda district, Telangana, India. The regions were categorised as high, moderate and low groundwater potential, and they were validated with the groundwater levels and yield of wells located in the corresponding zones. Extensive possibility for watershed development is possible in 41 % of the total 724 km2 and 46 % of the area offers moderate options. Any groundwater management project implemented in these favourable areas will bring maximum benefit. Similar studies should be considered necessary before designing a water resource development activity as it will reduce the cost on detailed field visits which are time-consuming.

  11. Tourist valorization of geomorphological objects of geo-heritage in Serbia

    Directory of Open Access Journals (Sweden)

    Stanković Stevan M.


    Full Text Available Right at the beginning of its work, geomorphology working group of the National council for geo- heritage has separated 200 relief objects and suggested them for enrolling into the geo heritage list. It has separated particularly the objects of mundane, European and Balkan significance. Most of them are interesting for tourist visits and are demanding a certain approach to valorization, so that right economical and social objects can be achieved. The objects of geo heritage in Serbia are placed in the primary and complementary tourist values which means they have different attractive zone and provide more kind of tourism. In the process of tourist valorization of the objects of geo heritage, we respect internal factors external factors and inlay work. Tourist-geographical position and level of attractiveness is of special significance so in dependence of that are local, regional, republic, national and international values being treated suitable for developing an adequate kind of domestic and foreign tourism.

  12. Flood risk analysis of the Limpopo River basin through past evolution reconstruction and geomorphological approach

    Directory of Open Access Journals (Sweden)

    M. Spaliviero


    Full Text Available This research reconstructs the past evolution of the Limpopo River, a transboundary system located in south-eastern Africa, and describes its geomorphological settings through literature review and field work activities, with aim to analyse the risk of floods in the basin. Major changes have occurred since the late Jurassic – early Cretaceous period due to successive tectonic events. The paper demonstrates that the apparently abandoned drainage conformation of the palaeo-Limpopo in the upper and middle stretches of the river constitutes today preferential flood-prone areas in case of major rainfall events. An important palaeo-delta is identified in the lower Limpopo, which imposes a particular drainage pattern to the floodplain in Mozambique and influences the floods dynamics at present. The adopted method is helpful in determining flood risk in a data-scarce area showing complex fluvial dynamics, and allows identifying unsuitable locations for human settlements.

  13. Geomorphology and fish assemblages in a Piedmont river basin, U.S.A (United States)

    Walters, D.M.; Leigh, D.S.; Freeman, Mary C.; Freeman, B.J.; Pringle, C.M.


    1. We investigated linkages between fishes and fluvial geomorphology in 31 wadeable streams in the Etowah River basin in northern Georgia, U.S.A. Streams were stratified into three catchment sizes of approximately 15, 50 and 100 km2, and fishes and geomorphology were sampled at the reach scale (i.e. 20?40 times stream width). 2. Non-metric multidimensional scaling (NMDS) identified 85% of the among-site variation in fish assemblage structure and identified strong patterns in species composition across sites. Assemblages shifted from domination by centrarchids, and other pool species that spawn in fine sediments and have generalised food preferences, to darter-cyprinid-redhorse sucker complexes that inhabit riffles and runs, feed primarily on invertebrates, and spawn on coarser stream beds. 3. Richness and density were correlated with basin area, a measure of stream size, but species composition was best predicted (i.e. |r| between 0.60?0.82) by reach-level geomorphic variables (stream slope, bed texture, bed mobility and tractive force) that were unrelated to stream size. Stream slope was the dominant factor controlling stream habitat. Low slope streams had smaller bed particles, more fines in riffles, lower tractive force and greater bed mobility compared with high slope streams. 4. Our results contrast with the `River Continuum Concept? which argues that stream assemblages vary predictably along stream size gradients. Our findings support the `Process Domains Concept?, which argues that local-scale geomorphic processes determine the stream habitat and disturbance regimes that influence stream communities.

  14. Rainfall simulators in hydrological and geomorphological sciences: benefits, applications and future research directions (United States)

    Iserloh, Thomas; Cerdà, Artemi; Fister, Wolfgang; Seitz, Steffen; Keesstra, Saskia; Green, Daniel; Gabriels, Donald


    Rainfall simulators are used extensively within the hydrological and geomorphological sciences and provide a useful investigative tool to understand many processes, such as: (i) plot-scale runoff, infiltration and erosion; (ii) irrigation and crop management, and; (iii) investigations into flooding within a laboratory setting. Although natural rainfall is desirable as it represents actual conditions in a given geographic location, data acquisition relying on natural rainfall is often hindered by its unpredictable nature. Furthermore, rainfall characteristics such as the intensity, duration, drop size distribution and kinetic energy cannot be spatially or temporally regulated or repeated between experimentation. Rainfall simulators provide a suitable method to overcome the issues associated with depending on potentially erratic and unpredictable natural rainfall as they allow: (i) multiple measurements to be taken quickly without waiting for suitable natural rainfall conditions; (ii) the simulation of spatially and/or temporally controlled rainfall patterns over a given plot area, and; (iii) the creation of a closed environment, allowing simplified measurement of input and output conditions. There is no standardisation of rainfall simulation and as such, rainfall simulators differ in their design, rainfall characteristics and research application. Although this impedes drawing meaningful comparisons between studies, this allows researchers to create a bespoke and tailored rainfall simulator for the specific research application. This paper summarises the rainfall simulators used in European research institutions (Universities of Trier, Valencia, Basel, Tuebingen, Wageningen, Loughborough and Ghent) to investigate a number of hydrological and geomorphological issues and includes details on the design specifications (such as the extent and characteristics of simulated rainfall), as well as a discussion of the purpose and application of the rainfall simulator.

  15. Bayesian network modeling applied to coastal geomorphology: lessons learned from a decade of experimentation and application (United States)

    Plant, N. G.; Thieler, E. R.; Gutierrez, B.; Lentz, E. E.; Zeigler, S. L.; Van Dongeren, A.; Fienen, M. N.


    We evaluate the strengths and weaknesses of Bayesian networks that have been used to address scientific and decision-support questions related to coastal geomorphology. We will provide an overview of coastal geomorphology research that has used Bayesian networks and describe what this approach can do and when it works (or fails to work). Over the past decade, Bayesian networks have been formulated to analyze the multi-variate structure and evolution of coastal morphology and associated human and ecological impacts. The approach relates observable system variables to each other by estimating discrete correlations. The resulting Bayesian-networks make predictions that propagate errors, conduct inference via Bayes rule, or both. In scientific applications, the model results are useful for hypothesis testing, using confidence estimates to gage the strength of tests while applications to coastal resource management are aimed at decision-support, where the probabilities of desired ecosystems outcomes are evaluated. The range of Bayesian-network applications to coastal morphology includes emulation of high-resolution wave transformation models to make oceanographic predictions, morphologic response to storms and/or sea-level rise, groundwater response to sea-level rise and morphologic variability, habitat suitability for endangered species, and assessment of monetary or human-life risk associated with storms. All of these examples are based on vast observational data sets, numerical model output, or both. We will discuss the progression of our experiments, which has included testing whether the Bayesian-network approach can be implemented and is appropriate for addressing basic and applied scientific problems and evaluating the hindcast and forecast skill of these implementations. We will present and discuss calibration/validation tests that are used to assess the robustness of Bayesian-network models and we will compare these results to tests of other models. This will

  16. Geomorphological and geochemistry changes in permafrost after the 2002 tundra wildfire in Kougarok, Seward Peninsula, Alaska (United States)

    Iwahana, Go; Harada, Koichiro; Uchida, Masao; Tsuyuzaki, Shiro; Saito, Kazuyuki; Narita, Kenji; Kushida, Keiji; Hinzman, Larry D.


    Geomorphological and thermohydrological changes to tundra, caused by a wildfire in 2002 on the central Seward Peninsula of Alaska, were investigated as a case study for understanding the response from ice-rich permafrost terrain to surface disturbance. Frozen and unfrozen soil samples were collected at burned and unburned areas, and then water isotope geochemistry and cryostratigraphy of the active layer and near-surface permafrost were analyzed to investigate past hydrological and freeze/thaw conditions and how this information could be recorded within the permafrost. The development of thermokarst subsidence due to ice wedge melting after the fire was clear from analyses of historical submeter-resolution remote sensing imagery, long-term monitoring of thermohydrological conditions within the active layer, in situ surveys of microrelief, and geochemical signals recorded in the near-surface permafrost. The resulting polygonal relief coincided with depression lines along an underground ice wedge network, and cumulative subsidence to 2013 was estimated as at least 10.1 to 12.1 cm (0.9-1.1 cm/year 11 year average). Profiles of water geochemistry in the ground indicated mixing or replenishment of older permafrost water with newer meteoric water, as a consequence of the increase in active layer thickness due to wildfire or past thaw event. Our geocryological analysis of cores suggests that permafrost could be used to reconstruct the permafrost degradation history for the study site. Distinct hydrogen and oxygen isotopic compositions above the Global Meteoric Water Line were found for water from these sites where permafrost degradation with geomorphological change and prolonged surface inundation were suggested.

  17. The case of Sarno River (Southern Italy): effects of geomorphology on the environmental impacts. (United States)

    De Pippo, Tommaso; Donadio, Carlo; Guida, Marco; Petrosino, Carmela


    Analysis of the morphological, geological and environmental characteristics of the Sarno River basin has shown the present degraded condition of the area. Over the past thirty years, the supply of untreated effluent of domestic, agricultural and industrial origin has ensured the presence of high concentrations of pollutants, including heavy metals. The geological context of the catchment area has played a major part in determining the current ecological conditions and public health problems: while human activity has modified the landscape, the natural order has indirectly contributed to increasing the environmental impact. The health situation is precarious as the basin's inhabitants feed on agricultural and animal products, and use polluted water directly or indirectly. The hazard of contracting degenerative illnesses of the digestive or respiratory apparatus, bacterial infections or some neoplasia has gradually increased, especially in the last five years. Moreover, polluted basin waters flowing into the Bay of Naples increase sea water contamination, thereby damaging tourism, public health and degrading the local littoral quality. The overview presented shows how the environmental state of the Sarno River basin gives considerable cause for concern. The basin's complex geomorphologic setting has a direct bearing on local environmental and health conditions. The analysis of the available data demonstrates how the physical aspects of the area are closely linked to the diffusion and concentration of the pollutants, and how the latter ones have a large influence on the hygienic-sanitary conditions of the local population. Specific interventions need to be undertaken to monitor and improve the chemical, physical and microbiological conditions of water and sediments, especially in light of the geomorphological vulnerability of the river basin.

  18. Quantitative Geomorphology: How computers have revolutionized the way we think about landscapes (United States)

    Braun, Jean; Davy, Philippe; Bonnet, Stéphane; Lundbek Egholm, David; Pelletier, Jon D.; Tucker, Gregory E.


    The field of geomorphology has seen a real revolution in the past 30 years in great part due to the development of landscape evolution models (LEMs). These models are based on the solution of a wide variety of equations including the stream power law to represent the incision by channelized flow, the under-capacity model that includes the effect of sediment flux on the stream erosional efficiency, various forms of the diffusion equation to represent the transport of material on hillslopes, and various other equations to represent the flow and erosion of ice, the dissolution of carbonate rocks to form karstic landscapes or eolian transport. The strength of the majority of these models is that they integrate in space and time the effects of processes described at the local scale. Most algorithms use classical methods to solve partial differential equations, like the finite difference, finite element or the finite volume technique; some use more exotic methods such as neural networks, statistical or automaton techniques. In this presentation, I will briefly present the variety of processes that have been simulated using LEMs, the basic equations that are solved as well as the techniques used to compute their solution. In a second step, I will review the principal results that have been obtained using LEMs and how they have influenced the way we now think about landscape evolution and its interactions with tectonics and climate. In particular, I will show how steady-state landforms have been be used to extract information about the underlying tectonics (uplift), I will describe how we think horizontal tectonic advection affects landform evolution and explain how the complex interactions between fluvial, glacial and hillslope processes during the recent glacial cycles are responsible for the formation of most mountainous landscapes. I will then briefly enumerate what are regarded as the main shortcomings of our models and describe some of the on-going developments in


    Directory of Open Access Journals (Sweden)

    Vedat AVCI


    Full Text Available In this study geomorphological features of Uludere Basin and the factors that are effective on gaining these features have been determined using morphometric indices. Morphometric analyses have been obtained from digital elevation model produced by the digitization of 1/25000 scale maps. In this study profile, slope, aspect, hipsographic analyses, relative reliefs and elevation frequency analysis have been done. Tectonic lines have determined the slope distribution, and the slope values in the west of the basin have increased accordingly. Active fault's cutting the basin in NW-SE direction has led to a difference in aspect between hillsides. Tectonism has caused the NNW-SSE hillsides to cover large areas in the field. A large number of small streams feeding the river basins take their sources from sharp hillsides and these streams have been offset due to the tectonic movements. Basin’s tectonically oriented has enabled it to gain a shape, as a result of this the area feeding the stream from the east has expanded. Uludere draining the basin’s streams indicates the feature of a subsekant stream because it has settled on tectonic lines. According to the elevation frequency analysis, in the basin, where relative relief goes up to 538 m in the west and falls below 100 m in the east, the most repeated elevation range is between 2600-2700 m and this is thought to be caused by young tectonic movements. The decline in relative relief in the east of the basin is related to the volcanic plains covering large areas. Noticeable elevation differences and asymmetry in transverse profiles indicate that the effect of tectonics is obvious on basin’s taking a shape and that the basin is in its early phase. Uludere Basin, geomorphology, morphometric analyses, tectonics.

  20. Evaluating the use of augmented reality to support undergraduate student learning in geomorphology (United States)

    Ockelford, A.; Bullard, J. E.; Burton, E.; Hackney, C. R.


    Augmented Reality (AR) supports the understanding of complex phenomena by providing unique visual and interactive experiences that combine real and virtual information and help communicate abstract problems to learners. With AR, designers can superimpose virtual graphics over real objects, allowing users to interact with digital content through physical manipulation. One of the most significant pedagogic features of AR is that it provides an essentially student-centred and flexible space in which students can learn. By actively engaging participants using a design-thinking approach, this technology has the potential to provide a more productive and engaging learning environment than real or virtual learning environments alone. AR is increasingly being used in support of undergraduate learning and public engagement activities across engineering, medical and humanities disciplines but it is not widely used across the geosciences disciplines despite the obvious applicability. This paper presents preliminary results from a multi-institutional project which seeks to evaluate the benefits and challenges of using an augmented reality sand box to support undergraduate learning in geomorphology. The sandbox enables users to create and visualise topography. As the sand is sculpted, contours are projected onto the miniature landscape. By hovering a hand over the box, users can make it `rain' over the landscape and the water `flows' down in to rivers and valleys. At undergraduate level, the sand-box is an ideal focus for problem-solving exercises, for example exploring how geomorphology controls hydrological processes, how such processes can be altered and the subsequent impacts of the changes for environmental risk. It is particularly valuable for students who favour a visual or kinesthetic learning style. Results presented in this paper discuss how the sandbox provides a complex interactive environment that encourages communication, collaboration and co-design.

  1. Small-scale opencast mining: an important research field for anthropogenic geomorphology

    Directory of Open Access Journals (Sweden)

    Byizigiro, R. Vaillant


    Full Text Available Artisanal and small-scale mining (A&SM is a growing economic sector in many third-world countries. This review focuses on anthropo-geomorphic factors and processes associated with small-scale opencast mining (SSOM, a form of A&SM in which near-surface ores are extracted by removing relatively thin covers of soil, bedrock or sediments. Being widespread and commonly conducted without proper planning and beyond the control of local authorities, this form of mining has potentially large impacts on landforms and landscape dynamics, often resulting in drastic consequences for the local environment and agriculture. SSOM should be regarded as a component of anthropogenic geomorphology because it involves the role of humans in creating landforms and modifying the operation of natural geomorphological processes, such as weathering, erosion, transport and deposition. By initiating new and modifying natural geomorphic processes, SSOM causes and/or accelerates geomorphic processes, resulting in various forms of land degradation. While the direct geomorphic impact of SSOM is in general easily discernible and leads to characteristic features, such as excavated pits and overburden spoil heaps, many secondary impacts are attributed to geomorphic processes triggered in the wake of the primary mining-induced landscape alterations. The magnitude of such secondary implications may well extend beyond the actual mining areas, but these effects have not been thoroughly addressed in the research so far. This review summarizes the known studies on the geomorphic impacts of SSOM operations and highlights common geomorphic processes and landforms associated with this type of anthropogenic activity, thus establishing a starting point for further in-depth research.

  2. Soils as Sediment database: closing a gap between soil science and geomorphology (United States)

    Kuhn, Nikolaus J.


    Soils are an interface between the Earth's spheres and shaped by the nature of the interaction between them. The relevance of soil properties for the nature of the interaction between atmosphere, hydrosphere and biosphere is well-studied and accepted, on point- or ecotone-scale. However, this understanding of the largely vertical connections between spheres is not matched by a similar recognition of soil properties affecting processes acting largely in a lateral way across the land surface, such as erosion, transport and deposition of soil. Key areas where such an understanding is essential are all issues related to the lateral movement of soil-bound substances that affect the nature of soils itself, as well as water or vegetation downslope from the source area. The redistribution of eroded soil falls several disciplines, most notably soil science, agronomy, hydrology and geomorphology. Accordingly, the way sediment is described differs: in soil science, aggregation and structure are essential properties, while most process-based soil erosion models treat soil as a mixture of individual mineral grains, based on concepts derived in fluvial geomorphology or civil engineering. The actual behavior of aggregated sediment is not reflected by either approach and difficult to capture due to the dynamic nature of aggregation, especially in an environment such as running water. Still, a proxy to assess the uncertainties introduced by aggregation on the behavior of soil as sediment would represent a step forward. To develop such a proxy, a database collating relevant soil and sediment properties could serve as an initial step to identify which soil types and erosion scenarios are prone to generate a high uncertainty compared to the use of soil texture in erosion models. Furthermore, it could serve to develop standardized analytical procedures for appropriate description of soil as sediment.

  3. Risks Associated To Present Geomorphologic Processes In The Stemnic (Buda River Basin

    Directory of Open Access Journals (Sweden)

    Bojoagă Ioan


    Full Text Available The paper analyses the main geomorphologic processes in the Stemnic (Buda river basin, conditioned by the joint action of several factors, among which are the lithological peculiarities and the nature of superficial deposits, morphometric characteristics, climate, vegetation type and structure, properties of the soil cover etc. The Stemnic river basin with an area of 15662.52 ha is characterized by its elongated shape (the maximum length is of 30.5 km, maximum width of 8.5 km, its relative lithological homogeneity, but also by a variety of superficial deposits (eluvium, diluvium, colluvium and proluvium, alluvium and by a relief energy of significant values between 136 m and 10 m (mean value of 73 m. Under these conditions, study area is characterized by a high degree of susceptibility to the occurrence of geomorphologic risk processes. For the morphometric and morphological analysis, we applied the method of the digital terrain model (DTM with vectorisation of the contour lines on topographic maps with a scale of 1:5,000. In this paper we used indicators that highlight the particular frequency of landslides, especially in the upper and middle sectors, but the rather reduced frequency of deep erosion. Due to the satisfactory coverage of the ground with vegetation, the erosion reaction is differentiated, as it depends on the use of the land and the concentration of liquid flow on the slopes. Consequently, landslides of different ages, types and forms hold large surfaces in the basin (approx. 8%, while surface erosion affects most areas of the slopes, but with different intensities depending on their use and on agricultural technologies.

  4. Evapotranspiration across plant types and geomorphological units in polygonal Arctic tundra (United States)

    Raz-Yaseef, Naama; Young-Robertson, Jessica; Rahn, Thom; Sloan, Victoria; Newman, Brent; Wilson, Cathy; Wullschleger, Stan D.; Torn, Margaret S.


    Coastal tundra ecosystems are relatively flat, and yet display large spatial variability in ecosystem traits. The microtopographical differences in polygonal geomorphology produce heterogeneity in permafrost depth, soil temperature, soil moisture, soil geochemistry, and plant distribution. Few measurements have been made, however, of how water fluxes vary across polygonal tundra plant types, limiting our ability to understand and model these ecosystems. Our objective was to investigate how plant distribution and geomorphological location affect actual evapotranspiration (ET). These effects are especially critical in light of the rapid change polygonal tundra systems are experiencing with Arctic warming. At a field site near Barrow, Alaska, USA, we investigated the relationships between ET and plant cover in 2014 and 2015. ET was measured at a range of spatial and temporal scales using: (1) An eddy covariance flux tower for continuous landscape-scale monitoring; (2) An automated clear surface chamber over dry vegetation in a fixed location for continuous plot-scale monitoring; and (3) Manual measurements with a clear portable chamber in approximately 60 locations across the landscape. We found that variation in environmental conditions and plant community composition, driven by microtopographical features, has significant influence on ET. Among plant types, ET from moss-covered and inundated areas was more than twice that from other plant types. ET from troughs and low polygonal centers was significantly higher than from high polygonal centers. ET varied seasonally, with peak fluxes of 0.14 mm h-1 in July. Despite 24 hours of daylight in summer, diurnal fluctuations in incoming solar radiation and plant processes produced a diurnal cycle in ET. Combining the patterns we observed with projections for the impact of permafrost degradation on polygonal structure suggests that microtopographic changes associated with permafrost thaw have the potential to alter tundra

  5. Relief inversion in the geomorphological evolution of sub-Saharan West Africa (United States)

    Butt, C. R. M.; Bristow, A. P. J.


    The geomorphology of much of sub-Saharan West Africa is dominated by the presence of plateaux and plains with ferruginous and, locally, aluminous (bauxitic) duricrusts. The plateaux occur at different elevations and have been correlated as two or more palaeosurfaces across much of the region. The duricrusts have generally been considered to be residual, formed by conformable erosion and chemical wasting of immediately underlying bedrock. This concept has been central to interpretations as diverse as the formation and evolution of the landscape and the development of geochemical exploration models. Recent regolith landform mapping, field observations and experience from mineral exploration in southern Mali and Burkina Faso, however, demonstrate that the duricrusts are mainly ferricretes, i.e., Fe oxide-cemented sediments. These observations require a re-interpretation of the geomorphological evolution of the region during the Cenozoic. The landscape has evolved by several cycles of weathering and erosion-deposition, triggered by climatic, tectonic or other environmental changes. It is proposed that an initial bauxitic/lateritic regolith was partly eroded following uplift and/or a change to a more arid climate, and that the detritus, rather than being removed, was deposited on slopes and valleys. During a subsequent humid period of lateritic weathering, Fe oxide cementation of this detritus formed ferricrete. Dehydration and hardening of the ferricrete after further uplift or aridity increased its resistance to erosion, resulting in relief inversion, with the detritus, in turn, being deposited downslope. This too has been weathered and cemented, to form a younger ferricrete. The occurrence of ferricrete landforms in adjacent countries, noted by field observation and inferred from satellite imagery, demonstrates that relief inversion is a very widespread and important phenomenon in southern Mali, Burkina Faso and adjacent countries in semi-arid West Africa.

  6. Geomorphology, hydrology, and ecology of Lake Urema, central Mozambique, with focus on lake extent changes (United States)

    Böhme, Beate; Steinbruch, Franziska; Gloaguen, Richard; Heilmeier, Hermann; Merkel, Broder

    Lake Urema is one of the most important ecological features of Gorongosa National Park, located in central Mozambique, in the East African Rift System. Understanding hydrology and ecology of the lake and its tributaries is particularly important for the conservation of the Park’s floodplain habitats and its biodiversity. There are concerns that hydrological boundary conditions and ecology of Lake Urema have changed in recent years. Possible causes for this change include climatic and land use changes as well as tectonic and geomorphological processes. In this study, a multi-temporal and multi-disciplinary approach was applied to investigate the dynamics and control mechanisms of Lake Urema. Principal methods comprised remote sensing analyses of time series of Landsat and ASTER data, geomorphological interpretations of a Digital Terrain Model (DTM) as well as field investigations such as analyses of water quality and sediment composition. The waters of Lake Urema have a low mineralization and pH values approximately neutral. The spatially dominant sediment type has a pure clay texture consisting of kaolinite and smectite. The sandy type consists of quartz, kali felspar, and plagioclase. The results of the supervised classifications for the satellite images from 1979 to 2000 showed that the lake’s extent ranged between 17 km 2 (09/1995) and 25 km 2 (08/1979). Above average rainfall was responsible for the extreme lake size in May 1997 (104 km 2). The interpretations of the Digital Terrain Model demonstrated that alluvial fans limit the Urema basin from all sides and make Lake Urema a form of “reservoir lake”. The control mechanisms of the hydrological regime of Lake Urema, such as the contribution of groundwater, are not yet fully understood. The lake’s condition during the rainy season was not investigated. In the future, investigations of the sources and amounts of sediment input into the lake should be conducted.

  7. Applications of geomorphology, tectonics, geology and geophysical interpretation of, East Kom Ombo depression, Egypt, using Landsat images

    Directory of Open Access Journals (Sweden)

    El Sayed A. El Gammal


    Full Text Available In the Southern Eastern Desert of Egypt, A NW–SE oriented structural graben extends from the North of Aswan to the Red Sea coast with a length of about 400 km and an average width of 30 km. The area has significant potential for development as it may be provided with water from surface and subsurface sources and is the site of prospection for petroleum. The present paper is an attempt to understand the structural evolution and genetic development of the geomorphologic features of the area and constructing presently a new geomorphological map at a scale of 1:250,000 using Landsat ETM images and field checks. Available geological maps and the produced geomorphological map are digitized by using the ARC-GIS software. The same program is also used to produce a 3D DEM for surface and subsurface features. Based on new interpretations of aeromagnetic and radiometric data, the subsurface features of the basement cover were illustrated on a 3D map. Geological–geomorphological profiles have been constructed in different directions in the area to identify present and ancient geomorphologic features. The place and shape of subsurface deep seated NW–SE trending faults have been determined. The faults, which generated the graben have downthrows in the order of 900–5800 m. The surface and subsurface observations delineate the dominant downthrow of about 3750 m. Three E–W subsurface faults have been detected under Nubia sandstone, one of them, displaying a downthrow of about 845 m, cuts through the basement rocks.

  8. Hidden gully erosion - detection and characterization of piping systems using geomorphological and geophysical methods (GPR, ERT) (United States)

    Bernatek-Jakiel, Anita; Kondracka, Marta


    The significance of piping in gully formation and hillslope hydrology has been discussed for many years. However, piping as a subsurface erosion caused by water flowing through the soil is still considered as one of the most difficult erosion processes to study, because it occurs below the soil surface and traces of piping become visible on the surface only when a pipe roof collapses, or a pipe inlet or a pipe outlet has been located. Detection of pipes and their complex characterization is still a methodological challenge. Therefore, this study aims at a better detection and characterization of piping systems in a mountainous area under a temperate climate using geomorphological mapping and geophysical methods (ground penetrating radar and electrical resistivity tomography). The survey was carried out in the Bereźnica Wyżna catchment, in the Bieszczady Mts. (Eastern Carpathians, Poland), where pipes develop in Cambisols at a depth ranging from ca 0.70 to 1.00 m. The geomorphological mapping was carried out in the in the whole catchment (2.96 km2), whereas the geophysical survey was limited to two zones (zone A - ca 32 x 82 m, zone B - ca 58 x 115 m). In this study a standard RAMAC GPR system (Malå GeoScience) with shielded 500 MHz antenna was used. The electrical resistivity tomography (ERT) was performed using electrical imaging system LUND with Terrameter SAS 4000 produced by company ABEM. The ERT and GPR data were interpreted in the RES2DINV (Geotomo Software) and RadExplorer software (DECO Geophysical Ltd) respectively. In total, 3 longitudinal and 26 transverse GPR profiles and five ERTs were performed. The used geophysical techniques are shown to be successful in identifying pipes tested in the pilot catchment. Pipes identified by GPR and ERT were verified by the surface indicators (i.e. lowering of surface above pipes). The GPR and ERT applications suggest that piping systems density is much greater than could be detected from surface observation alone

  9. Updated symbol catalogue for geologic and geomorphologic mapping in Planetary Scinces (United States)

    Nass, Andrea; Fortezzo, Corey; Skinner, James, Jr.; Hunter, Marc; Hare, Trent


    Maps are one of the most powerful communication tools for spatial data. This is true for terrestrial data, as well as the many types of planetary data. Geologic and/or geomorphologic maps of planetary surfaces, in particular those of the Moon, Mars, and Venus, are standardized products and often prepared as a part of hypothesis-driven science investigations. The NASA-funded Planetary Geologic Mapping program, coordinated by the USGS Astrogeology Science Center (ASC), produces high-quality, standardized, and refereed geologic maps and digital databases of planetary bodies. In this context, 242 geologic, geomorphologic, and thematic map sheets and map series have been published since the 1962. However, outside of this program, numerous non-USGS published maps are created as result of scientific investigations and published, e.g. as figures or supplemental materials within a peer-reviewed journal article. Due to the complexity of planetary surfaces, diversity between different planet surfaces, and the varied resolution of the data, geomorphologic and geologic mapping is a challenging task. Because of these limiting conditions, the mapping process is a highly interpretative work and is mostly limited to remotely sensed satellite data - with a few expetions from rover data. Uniform and an unambiguous data are fundamental to make quality observations that lead to unbiased and supported interpretations, especially when there is no current groundtruthing. To allow for correlation between different map products (digital or analog), the most commonly used spatial objects are predefined cartographic symbols. The Federal Geographic Data Committee (FGDC) Digital Cartographic Standard for Geologic Map Symbolization (DCSGMS) defines the most commonly used symbols, colors, and hatch patterns in one comprehensive document. Chapter 25 of the DCSGMS defines the Planetary Geology Features based on the symbols defined in the Venus Mapper's Handbook. After reviewing the 242 planetary

  10. A Geomorphologically Driven Conditional Assessment for the Study of Urban Stone Decay (United States)

    Johnston, Brian; McKinley, Jennifer; Warke, Patricia; Ruffell, Alastair


    Much of humanity's legacy is within the built environment and therefore in the stones that have been used for its construction. This means that targeted building conservation strategies are vital when considering the maintenance of this heritage. Conditional assessments play a major part in these efforts by classifying blocks based upon their visual state of decay. However, as these tools were developed with the purpose of informing decision making by professionals in the construction and conservation industries, limitations exist when considering them as part of studies with a geomorphological focus. Links between the decay of stonework and spatially variable control factors, such as material properties, microclimatic conditions and pollutant distribution, have been well documented in past studies, with observations of decay on wall sections supporting this concept. For example, the distribution of weathering features can indicate that certain blocks are more susceptible than others to decay. Additionally, adjoining blocks can exhibit similar processes, suggestive of interaction between the blocks, indicating a linkage between individual block scale decay and processes acting at a wider wall scale. These observations have led to comparisons between the weathering of rock outcrops and building façades, with mortar joints playing the role of fractures or bedding. This comparison has highlighted the necessity to not simply consider decay in terms of architecture or engineering, but also in terms of the geomorphological processes taking place. The patterns of decay created at a wall scale, whilst being visually chaotic, can provide clues to the controlling factors acting upon this system, if they are subjected to informed scrutiny. Despite such discussions, the focus of surveys towards remediation have created limitations when applying the results of these surveys towards the understanding of processes acting between blocks at a wall scale. This work aims to take

  11. Tectonic geomorphology of a large normal fault: Akşehir fault, SW Turkey (United States)

    Topal, Savaş; Keller, Edward; Bufe, Aaron; Koçyiğit, Ali


    In order to better understand the activity of the Akşehir normal fault in SW Turkey and the associated seismic hazard, we investigated the tectonic geomorphology of a 60-km stretch of the 100-km-long Akşehir fault block. The fault can be separated into seven geomorphic segments (1 to 7 from NW to SE) along the mountain front. Segment length varies from about 9 to 14 km, and relief of the horst block varies from about 0.6 km in the SE to 1.0 km in the NW. Analysis of the tectonic geomorphology of 32 drainage basins and mountain front facets using a combination of geomorphic indices reveals a general pattern of high slip rates in the northern and central segments and low slip rates in the southern, probably older, segments. We show that mountain front sinuosity varies from about 1.1 to 1.4 on segments S1-S6 to 2.4 on segment S7, suggesting that the six northern segments are more active than the southernmost segment. Similarly, χ analysis and slope-area analysis of streams reveal a pattern of steepest channels draining the central and northern segments of the horst. The ratio of valley floor width to valley height varies from 0.2 to 0.6, which are typical values for tectonically active mountain fronts; and alluvial fans along segments S1, S2, and S4 are back-tilted. Finally, we show that (1) shapes of the ~ 100-900m high mountain front facets are mostly triangular (~ 80%) and partly trapezoidal (~ 20%); (2) facet slopes range from 6 to 22°; (3) facets at the NW and SE segment ends are larger than the intervening facets; and (4) steepest facets occur along the central segments. Uplift rates estimated from the slope of mountain front facets range from about 0.06 m/ky on the southernmost fault segment (S7) to 0.23 m/ky on the more central S5 and 0.16 m/ky on the northern segment (S1). The estimated pattern of uplift is consistent with the pattern of geomorphic indices. The vertical relief of the facets suggests that uplift of the mountain front initiated in the late

  12. Mapping Drought Sensitivity of Ecosystem Functioning in Mountainous Watersheds: Spatial Heterogeneity and Geological-Geomorphological Control (United States)

    Wainwright, H. M.; Steefel, C. F.; Williams, K. H.; Hubbard, S. S.; Enquist, B. J.; Steltzer, H.; Sarah, T.


    Mountainous watersheds in the Upper Colorado River Basin play a critical role in supplying water and nutrients to western North America. Ecosystem functioning in those regions - including plant dynamics and biogeochemical cycling - is known to be limited by water availability. Under the climate change, early snowmelt and increasing temperature are expected to intensify the drought conditions in early growing seasons. Although the impact of early-season drought has been documented in plot-scale experiments, ascertaining its significance in mountainous watersheds is challenging given the highly heterogeneous nature of the systems with complex terrain and diverse plant functional types (PFTs). The objectives of this study are (1) to map the regions where the plant dynamics are relatively more sensitive to drought conditions based on historical satellite and climate data, and (2) to identify the environmental controls (e.g., geomorphology, elevation, geology, snow and PFT) on drought sensitivity. We characterize the spatial heterogeneity of drought sensitivity in four watersheds (a 15 x 15 km domain) near the Rocky Mountain Biological Laboratory in Colorado, USA. Following previous plot-scale studies, we first define the drought sensitivity based on annual peak NDVI (Landsat 5) and climatic datasets. Non-parametric tree-based machine learning methods are used to identify the significant environmental controls, using high-resolution LiDAR digital elevation map and peak snow-water-equivalent distribution from NASA airborne snow observatory. Results show that the drought sensitivity is negatively correlated with elevation, suggesting increased water limitations in lower elevation (less snow, higher temperature). The drought sensitivity is more spatially variable in shallow-rooted plant types, affected by local hydrological conditions. We also found geomorphological and geological controls, such as high sensitivity in the steep well-drained glacial moraine regions. Our

  13. Geomorphological features of active tectonics and ongoing seismicity of northeastern Kumaun Himalaya, Uttarakhand, India

    Indian Academy of Sciences (India)

    Vivekanand Pathak; Charu C Pant; Gopal Singh Darmwal


    The northeastern part of Kumaun Lesser Himalaya, Uttarakhand, India, lying between the rupture zones of 1905, Kangra and 1934, Bihar–Nepal earthquakes and known as ‘central seismic gap’ is a segment of an active fault known to produce significant earthquakes and has not slipped in an unusually long time when compared to other segments. The studied section forms a part of this seismic gap and is seismically an active segment of the Himalayan arc, as compared to the remaining part of the Kumaun Lesser Himalaya and it is evident by active geomorphological features and seismicity data. The geomorphological features of various river valley transects suggest that the region had a history of tectonic rejuvenation which is testified by the deposition of various levels of terraces and their relative uplift, shifting and ponding of river channels, uplifted potholes, triangular facets on fault planes, fault scarps, etc. Further, the seismic data of five-station digital telemetered seismic network along with two stand alone systems show the distribution of earthquakes in or along the analyzed fault transects. It is observed that the microseismic earthquakes (magnitude 1.0–3.0) frequently occur in the region and hypocenters of these earthquakes are confined to shallow depths (10–20 km), with low stress drop values (1.0–10 bar) and higher peak ground velocity (PGV). The cluster of events is observed in the region, sandwiched between the Berinag Thrust (BT) in south and Main Central Thrust (MCT) in north. The occurrences of shallow focus earthquakes and the surface deformational features in the different river valley transect indicates that the region is undergoing neotectonic rejuvenation. In absence of chronology of the deposits it is difficult to relate it with extant seismicity, but from the geomorphic and seismic observations it may be concluded that the region is still tectonically active. The information would be very important in identifying the areas of

  14. Evolutionary geomorphology: thresholds and nonlinearity in landform response to environmental change

    Directory of Open Access Journals (Sweden)

    J. D. Phillips


    Full Text Available Geomorphic systems are typically nonlinear, owing largely to their threshold-dominated nature (but due to other factors as well. Nonlinear geomorphic systems may exhibit complex behaviors not possible in linear systems, including dynamical instability and deterministic chaos. The latter are common in geomorphology, indicating that small, short-lived changes may produce disproportionately large and long-lived results; that evidence of geomorphic change may not reflect proportionally large external forcings; and that geomorphic systems may have multiple potential response trajectories or modes of adjustment to change. Instability and chaos do not preclude predictability, but do modify the context of predictability. The presence of chaotic dynamics inhibits or excludes some forms of predicability and prediction techniques, but does not preclude, and enables, others. These dynamics also make spatial and historical contingency inevitable: geography and history matter. Geomorphic systems are thus governed by a combination of ''global'' laws, generalizations and relationships that are largely (if not wholly independent of time and place, and ''local'' place and/or time-contingent factors. The more factors incorporated in the representation of any geomorphic system, the more singular the results or description are. Generalization is enhanced by reducing rather than increasing the number of factors considered. Prediction of geomorphic responses calls for a recursive approach whereby global laws and local contingencies are used to constrain each other. More specifically a methodology whereby local details are embedded within simple but more highly general phenomenological models is advocated. As landscapes and landforms change in response to climate and other forcings, it cannot be assumed that geomorphic systems progress along any particular pathway. Geomorphic systems are evolutionary in the sense of being path

  15. Improving Data Discovery, Access, and Analysis to More Than Three Decades of Oceanographic and Geomorphologic Observations (United States)

    Forte, M.; Hesser, T.; Knee, K.; Ingram, I.; Hathaway, K. K.; Brodie, K. L.; Spore, N.; Bird, A.; Fratantonio, R.; Dopsovic, R.; Keith, A.; Gadomski, K.


    The U.S. Army Engineer Research and Development Center's (USACE ERDC) Coastal and Hydraulics Laboratory (CHL) Coastal Observations and Analysis Branch (COAB) Measurements Program has a 35-year record of coastal observations. These datasets include oceanographic point source measurements, Real-Time Kinematic (RTK) GPS bathymetry surveys, and remote sensing data from both the Field Research Facility (FRF) in Duck, NC and from other project and experiment sites around the nation. The data has been used to support a variety of USACE mission areas, including coastal wave model development, beach and bar response, coastal project design, coastal storm surge, and other coastal hazard investigations. Furthermore these data have been widely used by a number of federal and state agencies, academic institutions, and private industries in hundreds of scientific and engineering investigations, publications, conference presentations and model advancement studies. A limiting factor to the use of FRF data has been rapid, reliable access and publicly available metadata for each data type. The addition of web tools, accessible data files, and well-documented metadata will open the door to much future collaboration. With the help of industry partner RPS ASA and the U.S. Army Corps of Engineers Mobile District Spatial Data Branch, a Data Integration Framework (DIF) was developed. The DIF represents a combination of processes, standards, people, and tools used to transform disconnected enterprise data into useful, easily accessible information for analysis and reporting. A front-end data portal connects the user to the framework that integrates both oceanographic observation and geomorphology measurements using a combination of ESRI and open-source technology while providing a seamless data discovery, access, and analysis experience to the user. The user interface was built with ESRI's JavaScript API and all project metadata is managed using Geoportal. The geomorphology data is made

  16. Tri-stereo Pleiades images-derived digital surface models for tectonic geomorphology studies (United States)

    Ferry, Matthieu; Le Roux-Mallouf, Romain; Ritz, Jean-François; Berthet, Théo; Peyret, Michel; Vernant, Philippe; Maréchal, Anaïs; Cattin, Rodolphe; Mazzotti, Stéphane; Poujol, Antoine


    Very high resolution digital elevation models are a key component of modern quantitative geomorphology. In parallel to high-precision but time-consuming kinematic GPS and/or total station surveys and dense coverage but expensive LiDAR campaigns, we explore the usability of affordable, flexible, wide coverage digital surface models (DSMs) derived from Pleiades tri-stereo optical images. We present two different approaches to extract DSM from a triplet of images. The first relies on the photogrammetric extraction of 3 DSMs from the 3 possible stereo couples and subsequent merge based on the best correlation score. The second takes advantage of simultaneous correlation over the 3 images to derive a point cloud. We further extract DSM from panchromatic 0.5 m resolution images and multispectral 2 m resolution images to test for correlation and noise and determine optimal correlation window size and achievable resolution. Georeferencing is also assessed by comparing raw coordinates derived from Pleiades Rational Polynomial Coefficients to ground control points. Primary images appear to be referenced within ~15 m over flat areas where parallax is minimal while derived DSMs and associated orthorectified images show a much improved referencing within ~5 m of GCPs. In order to assess the adequacy of Pleiades DSMs for tectonic geomorphology, we present examples from case studies along the Trougout normal fault (Morocco), the Hovd strike-slip fault (Mongolia), the Denali strike-slip fault (USA and Canada) and the Main Frontal Thrust (Bhutan). In addition to proposing a variety of tectonic contexts, these examples cover a wide range of climatic conditions (semi-arid, arctic and tropical), vegetation covers (bare earth, sparse Mediterranean, homogeneous arctic pine, varied tropical forest), lithological natures and related erosion rates. The capacity of derived DSMs is demonstrated to characterize geomorphic markers of active deformation such as marine and alluvial terraces

  17. Dynamics of Bottomland Geomorphology and Vegetation Along a Dammed, Arid Region River: Implications for Streamflow Management (United States)

    Shafroth, P. B.; House, P. K.


    In arid and semiarid western North America, floodplain forests dominated by native cottonwood and willow trees are highly valued as wildlife habitat and preferred recreation sites and are thus the focus of conservation efforts. The Bill Williams River harbors some of the most extensive native floodplain forests in the lower Colorado River region. Our work is aimed at understanding the dynamics of the Bill Williams River floodplain forests, in the context of pre- and post-dam hydrology and geomorphology. We have mapped bottomland geomorphology and vegetation using seven sets of orthorectified aerial photographs spanning more than 50 years. Two sets of photos (1953 and 1964) pre-date the completion of Alamo Dam, a large flood control structure; and three sets of photos (1996, 2002, and 2005) are from an era during which streamflow downstream of the dam has been managed to promote the establishment and survival of native floodplain forest. Comparison of the aerial photographs to LiDAR data collected in 2005 is providing a framework for quantifying changes in valley bottom morphology and estimating reach-scale changes in volumes of stored and evacuated sediment between 1953 and 2005. Furthermore, comparison of the extent of pre-dam active channel in 1953 with the extent of floodwaters from a regulated moderate flood in 2005 provides an approximation of the predominant patterns of aggradation and degradation in the system over this interval of time. Flood magnitude on the Bill Williams has been dramatically reduced since the closure of Alamo Dam in 1968, and low flows have increased considerably since 1979. Channels along the Bill Williams R. narrowed an average of 111 m (71 %) between 1953 and 1987, with most narrowing occurring after dam closure. Multiple regression analysis revealed significant relationships among flood power, summer flows, intermittency (independent variables) and channel width (dependent variable). Concurrent with channel narrowing was an expansion

  18. Structural data, geomorphology and rock slides in the SW of Barles (The Alps of Northern Provence, France)

    Energy Technology Data Exchange (ETDEWEB)

    Bureau, D.


    The Alps of northern Provence in France is a familiar area to European geologists because numerous, long field studies have been organized by European universities and private petroleum companies during the 20th century and the beginning of the 21st century. Nevertheless, geologists have made few comments on the consequences of some topographic slides and, more broadly, on the manner by which nature has sculpted the local geomorphology. After having set the local tectonic data (the thrust of the Blayeul Massif on an already folded para-autochtonous formation and locally up and down reversals in the area of the Heights of Chine and Proussier), a geological and geomorphological summary introduces a discussion on slides and slope formations; then the details of the morphology analysis lead us to the conclusions. (Author)

  19. Geomorphological analysis in soil profile assessment of the margin of Warsaw morainic plateau in Ursynów

    Directory of Open Access Journals (Sweden)

    Garbulewski Kazimierz


    Full Text Available This paper addresses the application of geomorphological analysis to recognize the geotechnical conditions at the margin of a moraine plateau in Warsaw. Aerial photographs, borehole data logging, CPT and DMT tests results were taken into account to compare the conditions at two sites, i.e. the well recognized part of the moraine plateau (SGGW Stadium site and the second part located at a distance of 5 km (Warsaw slope – church. Spatial variability of the strength and deformation properties in the study areas were determined using CPT and DMT tests results. The general conclusion is that the specific geomorphological units allow for prediction to some extent the sequence of geotechnical layers and the general distribution of soil parameters. The example from the margin of the moraine plateau in Warsaw shows that such procedure is a promising statistical tool related to geotechnical problems.

  20. Transferring measured discharge time series: Large-scale comparison of Top-kriging to geomorphology-based inverse modeling (United States)

    de Lavenne, A.; Skøien, J. O.; Cudennec, C.; Curie, F.; Moatar, F.


    Few methods directly transfer streamflow measurements for continuous prediction of ungauged catchments. Top-kriging has been used mainly to predict the statistical properties of runoff but has been shown to outperform traditional regionalization approaches of rainfall-runoff models. We applied the Top-kriging approach across the Loire River basin and compared predictions to a geomorphology-based approach. Whereas Top-kriging uses spatial correlation, the other approach has the advantage of being more physically based by using a well-known geomorphology-based hydrological model (WFIUH) and its inversion. Both approaches require an equal degree of calibration and provide similar performances. We also demonstrate that the Ghosh distance, which considers the nested nature of catchments, can be used efficiently to calculate weights and to identify the suitability of gauged catchments for use as donor catchments. This result is particularly relevant for catchments with Strahler orders above five, i.e., where donor catchments are more strongly nested.


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    Sumiko Kubo


    Full Text Available The geomorphological features of the Lower Mekong Plain and their relationships with floods, as well asthe subsurface geology and the major depositional processes in the area, are discussed. From theinterpretation of aerial photos and field reconnaissance, the Lower Mekong Plain in Cambodia ischaracterized as a floodplain with natural levees and back marshes. These geomorphological featuresinfluence the extent of the extensive inundation that occurs during every rainy (wet season. An extremeflood in 2000 confirmed the close relationship between micro-landforms and the flooding. A preliminarystudy of bore-hole logs in the area of Phnom Penh was also carried out. Base rocks are shallower in thewestern part, whereas thick (>130 m Quaternary deposits occur in the eastern part, suggesting the presenceof a structural basin.

  2. Environmental assessment of the area surrounding Dam Rio Verde - Parana/Brazil. An overview of environmental geomorphology. (United States)

    Garcia, Claudia Moreira; Carrijo, Beatriz Rodrigues; Sessegolo, Gisele; Passos, Everton


    This paper presents a brief essay on the situation in which the environment of the dam of the Rio Verde Basin-Parana, from the vision of environmental geomorphology. The area is located between the cities of Campo Magro and Campo Largo, Paraná plateau in the first part of theAlto Iguaçu basin. This study aims to raise the concepts relating to environmental geomorphology, to identify the anthropogenic impacts caused in the reservoir areas, identify the environmental compartments found around the dam and characterize the geologic and physiographic region. It was found that the area has intense anthropogenic influence, as urban growth is present in areas and wavy and rough terrain, subject to mass movements and floods. Besides these aspects, the use of land for agriculture contributes to fragility of the area.

  3. Connecting geomorphology to dust emission through high-resolution mapping of global land cover and sediment supply (United States)

    Parajuli, Sagar Prasad; Zender, Charles S.


    A key challenge in modeling dust emissions is to represent the location and strength of dust sources. One critical aspect of dust sources that is not well understood and thus not represented in dust models is their geomorphology. In this work, we investigate the geomorphology of global dust sources by developing two high-resolution (∼500 m), seamless, global maps. First is a land surface map in which landforms are classified into different categories based on geomorphology using an image classification technique. The land surface map shows the distribution of landforms in dust source regions and is useful in defining the boundaries of different dust sources in dust models. Second is the sediment supply map developed by combining the upstream drainage area with the visible reflectance retrieved by the Moderate-resolution Imaging Spectroradiometer (MODIS). This map, due to the inclusion of surface reflectance, highlights dust sources such as playa/sabkha and sand dunes and anthropogenic dust sources such as agricultural areas, that may not be captured by the commonly used elevation-based erodibility maps. We establish the connection between geomorphology and dust emission by comparing the sediment supply map with the land surface map and dust frequency map, qualitatively and quantitatively. We show that the sediment supply is linked to the land surface type and that playa/sabkha corresponds to the greatest inferred sediment supply. The sediment supply map is largely consistent with the land surface map and correlates well with the frequency of occurrence map derived from high-resolution MODIS level-2 aerosol optical depth (AOD) data.

  4. Photogrammetric Methodology for the Production of Geomorphologic Maps: Application to the Veleta Rock Glacier (Sierra Nevada, Granada, Spain)


    José Jesús Guerrero; Javier de Matías; José Juan de Sanjosé; Gonzalo López-Nicolás; Carlos Sagüés


    In this paper we present a stereo feature-based method using SIFT (Scale-invariant feature transform) descriptors. We use automatic feature extractors, matching algorithms between images and techniques of robust estimation to produce a DTM (Digital Terrain Model) using convergent shots of a rock glacier.The geomorphologic structure observed in this study is the Veleta rock glacier (Sierra Nevada, Granada, Spain). This rock glacier is of high scientific interest because it is the southernmost ...

  5. Principle and geomorphological applicability of summit level and base level technique using Aster Gdem satellite-derived data and the original software Baz


    Akihisa Motoki; Kenji Freire Motoki; Susanna Eleonora Sichel; Samuel da Silva; José Ribeiro Aires


    This article presents principle and geomorphological applicability of summit level technique using Aster Gdem satellite-derived topographicdata. Summit level corresponds to thevirtualtopographic surface constituted bylocalhighest points, such as peaks and plateau tops, and reconstitutes palaeo-geomorphology before the drainage erosion. Summit level map is efficient for reconstitution of palaeo-surfaces and detection of active tectonic movement. Base level is thevirtualsurface composed oflocal...

  6. Glacial erosion in limestone, yes or no? A comment on the black and white geotectonic interpretation of geomorphological settings of the Triglav Lakes Valley

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    Jurij Kunaver


    Full Text Available The paper offers some critical remarks on the tectonic interpretation of the geomorphologi-cal evolution of the Triglav Lakes Valley (the southern part of Julian Alps, Slovenia which denies not only the importance of the glacial erosion during the last Pleistocene glaciation, but also other morphogenetic agents during the Pleistocene and before (Šmuc, Rožič, 2009. By our opinion, the glacial and non-glacial morphogenetic factors were completely neglected in this paper.

  7. Actual geomorphological processes on steep hillslope vineyards. A comparison of Ruwertal (Germany) with the Montes de Málaga (Spain). (United States)

    Rodrigo Comino, Jesús; Damián Ruiz Sinoga, José; María Senciales González, José; Guerra Merchán, Antonio; Seeger, Manuel; Ries, Johannes B.


    Nowadays, steep hillslope viticulture areas are one of the most complex agricultural eco-geomorphological systems in Europe. Precisely, the vineyards of the Ruwer-Mosel valley (Germany) and Montes de Málaga-Axarquía (Spain) are one clear example. Both regions are characterized by frequent heavy rainfall events, concentrated in summer (Germany) and autumn-winter (Spain), and intensive and not conservative land use managements on the soil (application of vine training systems, herbicides, non ecological amendments, anthropic rills generated by wheel traffic, footsteps in Germany and built by hoes or shovels in Spain). The goals of this work were: i) to determine and to quantify the hydrological and erosive phenomena in two traditional hillslope vineyards in Waldrach (Ruwer-Mosel valley, Germany) and Almáchar (Montes de Málaga-Axarquía, Spain); ii) to compare the geomorphological and hydrological dynamics of these study areas during diverse seasons and under different management conditions (Mediterranean and Continental climatic contexts, application of machineries, traditional protection measures...). For this purpose, a combined methodology performed by Trier and Málaga Universities with soil analysis, sediment traps, rainfall simulations and Guelph permeameter were applied. The main results showed high soil erosion and similar variations in the runoff and infiltration rates. In both study areas, geomorphological and hydrological dynamics registered several spatiotemporal variations along the upper, middle and foot slope, and during different seasons (before and after the vintage, and between the dry and humid period).

  8. Geomorphology and sediment transport on a submerged back-reef sand apron: One Tree Reef, Great Barrier Reef (United States)

    Harris, Daniel L.; Vila-Concejo, Ana; Webster, Jody M.


    Back-reef sand aprons are conspicuous and dynamic sedimentary features in coral reef systems. The development of these features influences the evolution and defines the maturity of coral reefs. However, the hydrodynamic processes that drive changes on sand aprons are poorly understood with only a few studies directly assessing sediment entrainment and transport. Current and wave conditions on a back-reef sand apron were measured during this study and a digital elevation model was developed through topographic and bathymetric surveying of the sand apron, reef flats and lagoon. The current and wave processes that may entrain and transport sediment were assessed using second order small amplitude (Stokes) wave theory and Shields equations. The morphodynamic interactions between current flow and geomorphology were also examined. The results showed that sediment transport occurs under modal hydrodynamic conditions with waves the main force entraining sediment rather than average currents. A morphodynamic relationship between current flow and geomorphology was also observed with current flow primarily towards the lagoon in shallow areas of the sand apron and deeper channel-like areas directing current off the sand apron towards the lagoon or the reef crest. These results show that the short-term mutual interaction of hydrodynamics and geomorphology in coral reefs can result in morphodynamic equilibrium.

  9. Forensic geoscience: applications of geology, geomorphology and geophysics to criminal investigations (United States)

    Ruffell, Alastair; McKinley, Jennifer


    One hundred years ago Georg Popp became the first scientist to present in court a case where the geological makeup of soils was used to secure a criminal conviction. Subsequently there have been significant advances in the theory and practice of forensic geoscience: many of them subsequent to the seminal publication of "Forensic Geology" by Murray and Tedrow [Murray, R., Tedrow, J.C.F. 1975 (republished 1986). Forensic Geology: Earth Sciences and Criminal Investigation. Rutgers University Press, New York, 240 pp.]. Our review places historical development in the modern context of how the allied disciplines of geology (mineralogy, sedimentology, microscopy), geophysics, soil science, microbiology, anthropology and geomorphology have been used as tool to aid forensic (domestic, serious, terrorist and international) crime investigations. The latter half of this paper uses the concept of scales of investigation, from large-scale landforms through to microscopic particles as a method of categorising the large number of geoscience applications to criminal investigation. Forensic geoscience has traditionally used established non-forensic techniques: 100 years after Popp's seminal work, research into forensic geoscience is beginning to lead, as opposed to follow other scientific disciplines.

  10. Rios de leito rochoso: aspectos geomorfológicos fundamentais / Bedrock Rivers: fundamental geomorphologic aspects

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    Adalto Gonçalves de Lima


    Full Text Available ResumoOs estudos sobre rios de leito rochoso desenvolveram-se grandemente nas ultimas décadas, mas no Brasil, esses estudos ainda são incipientes. Considerando o estado recente do desenvolvimento desse tema e a escassez de trabalhos em língua portuguesa, e feita uma revisão dos aspectos geomorfológicos fundamentais desses rios com base nos estudos atuais. Primeiramente analisa-se o conceito de canais fluviais de leito rochoso. Em segundo lugar são analisados os princípios hidráulicos que governam a erosão em leitos rochosos. Finalmente, os processos erosivos de abrasão, arranque e cavitação são descritos a partir das pesquisas atuais. AbstractThe studies about bedrock rivers have been largely developed in last decades, but in Brazil these studies are still incipient. Considering the recent development of this theme and the scarcity of related research in Portuguese language, it is conducted a revision of fundamental geomorphologic aspects of bedrock rivers based on current studies. First of all, it is analyzed the bedrock river concept and after that, it is analyzed the hydraulic principles that govern the bedrock erosion. Finally, the erosive processes of abrasion, plucking and cavitation are described from current researches.

  11. Stratigraphy, geomorphology, geochemistry and hazard implications of the Nejapa Volcanic Field, western Managua, Nicaragua (United States)

    Avellán, Denis Ramón; Macías, José Luis; Pardo, Natalia; Scolamacchia, Teresa; Rodriguez, Dionisio


    The Nejapa Volcanic Field (NVF) is located on the western outskirts of Managua, Nicaragua. It consists of at least 30 volcanic structures emplaced along the N-S Nejapa fault, which represents the western active edge of the Managua Graben. The study area covers the central and southern parts of the volcanic field. We document the basic geomorphology, stratigraphy, chemistry and evolution of 17 monogenetic volcanic structures: Ticomo (A, B, C, D and E); Altos de Ticomo; Nejapa; San Patricio; Nejapa-Norte; Motastepe; El Hormigón; La Embajada; Asososca; Satélite; Refinería; and Cuesta El Plomo (A and B). Stratigraphy aided by radiocarbon dating suggests that 23 eruptions have occurred in the area during the past ~ 34,000 years. Fifteen of these eruptions originated in the volcanic field between ~ 28,500 and 2,130 yr BP with recurrence intervals varying from 400 to 7,000 yr. Most of these eruptions were phreatomagmatic with minor strombolian and fissural lava flow events. A future eruption along the fault might be of a phreatomagmatic type posing a serious threat to the more than 500,000 inhabitants in western Managua.

  12. Flood management on the lower Yellow River: hydrological and geomorphological perspectives (United States)

    Shu, Li; Finlayson, Brian


    The Yellow River, known also as "China's Sorrow", has a long history of channel changes and disastrous floods in its lower reaches. Past channel positions can be identified from historical documentary records and geomorphological and sedimentological evidence. Since 1947, government policy has been aimed at containing the floods within artificial levees and preventing the river from changing its course. Flood control is based on flood-retarding dams and off-stream retention basins as well as artificial levees lining the channel. The design flood for the system has a recurrence interval of only around 60 years and floods of this and larger magnitudes can be generated downstream of the main flood control dams at Sanmenxia and Xiaolangdi. Rapid sedimentation along the river causes problems for storage and has raised the bed of the river some 10 m above the surrounding floodplain. The present management strategy is probably not viable in the long term and to avoid a major disaster a new management approach is required. The most viable option would appear to be to breach the levees at predetermined points coupled with advanced warning and evacuation of the population thus put at risk.

  13. Geomorphological and sedimentary evidence of probable glaciation in the Jizerské hory Mountains, Central Europe (United States)

    Engel, Zbyněk; Křížek, Marek; Kasprzak, Marek; Traczyk, Andrzej; Hložek, Martin; Krbcová, Klára


    The Jizerské hory Mountains in the Czech Republic have traditionally been considered to be a highland that lay beyond the limits of Quaternary glaciations. Recent work on cirque-like valley heads in the central part of the range has shown that niche glaciers could form during the Quaternary. Here we report geomorphological and sedimentary evidence for a small glacier in the Pytlácká jáma Hollow that represents one of the most-enclosed valley heads within the range. Shape and size characteristics of this landform indicate that the hollow is a glacial cirque at a degraded stage of development. Boulder accumulations at the downslope side of the hollow probably represent a relic of terminal moraines, and the grain size distribution of clasts together with micromorphology of quartz grains from the hollow indicate the glacial environment of a small glacier. This glacier represents the lowermost located such system in central Europe and provides evidence for the presence of niche or small cirque glaciers probably during pre-Weichselian glacial periods. The glaciation limit (1000 m asl) and paleo-ELA (900 m asl) proposed for the Jizerské hory Mountains implies that central European ranges lower than 1100 m asl were probably glaciated during the Quaternary.

  14. Geomorphology and depositional subenvironments of Gulf Islands National Seashore, Perdido Key and Santa Rosa Island, Florida (United States)

    Morton, Robert A.; Montgomery, Marilyn C.


    The U.S. Geological Survey (USGS) is studying coastal hazards and coastal change to improve our understanding of coastal ecosystems and to develop better capabilities of predicting future coastal change. One approach to understanding the dynamics of coastal systems is to monitor changes in barrier-island subenvironments through time. This involves examining morphologic and topographic change at temporal scales ranging from millennia to years and spatial scales ranging from tens of kilometers to meters. Of particular interest are the processes that produce those changes and the determination of whether or not those processes are likely to persist into the future. In these analyses of hazards and change, both natural and anthropogenic influences are considered. Quantifying past magnitudes and rates of coastal change and knowing the principal factors that govern those changes are critical to predicting what changes are likely to occur under different scenarios, such as short-term impacts of extreme storms or long-term impacts of sea-level rise. Gulf Islands National Seashore was selected for detailed mapping of barrier-island morphology and topography because the islands offer a diversity of depositional subenvironments and because island areas and positions have changed substantially in historical time. The geomorphologic and subenvironmental maps emphasize the processes that formed the surficial features and also serve as a basis for documenting which subenvironments are relatively stable, such as the vegetated barrier core, and those which are highly dynamic, such as the beach and inactive overwash zones.

  15. Geomorphologic evolution and environmental changes in the Shaluli Mountain region during the Quaternary

    Institute of Scientific and Technical Information of China (English)

    ZHOU Shangzhe; XU Liubing; CUI Jianxin; ZHANG Xiaowei; ZHAO Jingdong


    Geologic and geomorphologic evidence from the Shaluli Mountain indicates that the planation surface that formed in the Late Tertiary disintegrated during the Late Pliocene-Early Quaternary. At the same time, rift basins appeared on some parts of the planation surface, and began to accumulate fluvial-lacustrine sediment. These are interpreted as being the response of this region to Phase-A of the Qingzang Tectonic Movement. After this, the Shaluli Mountain continued to rise in several pulses. Faulting and incision by some large tributaries of the Jinsha and Yalong Rivers resulted in several rift river valleys and the earliest terraces. Generally, the planation surface in this region had been uplifted to about 3500-3700 m a.s.l. no later than 550-600 ka BP, after the Kunlun-Huanghe Tectonic Movement, and coupled with global glacial climate, and resulted in the earliest glaciation recognized so far in the Hengduan Mountains. At the same time, loess was deposited in the Ganzi area of the northern Shaluli Mountain. During the last glacial period, the Shaluli Mountain approached its present altitude and developed several large ice caps, such as the Daocheng Ice Cap and Xinlong Ice Cap, as well as several huge valley glaciers. These paleoglaciers produced some of the most spectacular glacial topography on the Tibetan Plateau.

  16. MAGIC-DML: Mapping/Measuring/Modeling Antarctic Geomorphology & Ice Change in Dronning Maud Land (United States)

    Rogozhina, Irina; Bernales, Jorge; Newall, Jennifer; Stroeven, Arjen; Harbor, Jonathan; Glasser, Neil; Fredin, Ola; Fabel, Derek; Hättestrand, Class; Lifton, Nat


    Reconstructing and predicting the response of the Antarctic Ice Sheet to climate change is one of the major challenges facing the Earth Science community. There are critical gaps in our knowledge of past changes in ice elevation and extent in many regions of East Antarctica, including a large area of Dronning Maud Land. An international Swedish-UK-US-Norwegian-German project MAGIC-DML aims to reconstruct the timing and pattern of ice surface elevation (thus ice sheet volume) fluctuations since the mid-Pliocene warm period on the Dronning Maud Land margin of the East Antarctic Ice Sheet. A combination of remotely sensed geomorphological mapping, field investigations, surface exposure dating and numerical modelling are being used in an iterative manner to produce a comprehensive reconstruction of the glacial history of Dronning Maud Land. Here we present the results from the first phase of this project, which involves high-resolution numerical simulations of the past glacial geometries and mapping of the field area using historic and recent aerial imagery together with a range of satellite acquired data.

  17. Correlation Between Coastal Geomorphology and Tsunami Inundation Along the Coast of Kanyakumari, India

    Institute of Scientific and Technical Information of China (English)

    N. Chandrasekar; S. Saravanan; M. Rajamanickam; C. Hentry; G. V. Rajamanickam


    An investigation has been carried out in the vicinity of the coastal villages of Kanyakumari District,India to decode the influence of coastal geomorphology on inundation degree and run-up level.Even though the tsunami waves approach the study area in different patterns,the consequences are found to be mainly dependent upon the coastal configuration and local geographic setting,the study area are considered to be of three types based upon the geomorphic arrangement,namely shallow coast,elevated coast and estuarine coast.The inundation and run-up level vary from coast to coast even though there is no remarkable variation in the intensity of the approaching tsunami surge.The inundation extent ranges from to 54 m to 4 1 3 m with maximum along estuarine coast and minimum along elevated coast.Estuarine coast recorded the maximum run-up level of about 6 m and the minimum of about 1 m along the elevated coast.The percentage of inundated area in the total coastal area varies between 19% to 10% along estuarine coast and elevated coast respectively.Inundation and run-up level cannot be appreciable in the inland along the elevated coast.The beaches of elevated coast are less affected whereas those of estuarine coast are highly affected.Inundation is limited in the elevated beaches along the study area.

  18. Geochronology and Geomorphology of the Pioneer Archaeological Site (10BT676), Upper Snake River Plain, Idaho

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    Keene, Joshua L. [Idaho National Lab. (INL), Idaho Falls, ID (United States)


    The Pioneer site in southeastern Idaho, an open-air, stratified, multi-component archaeological locality on the upper Snake River Plain, provides an ideal situation for understanding the geomorphic history of the Big Lost River drainage system. We conducted a block excavation with the goal of understanding the geochronological context of both cultural and geomorphological components at the site. The results of this study show a sequence of five soil formation episodes forming three terraces beginning prior to 7200 cal yr BP and lasting until the historic period, preserving one cultural component dated to ~3800 cal yr BP and multiple components dating to the last 800 cal yr BP. In addition, periods of deposition and stability at Pioneer indicate climate fluctuation during the middle Holocene (~7200-3800 cal yr BP), minimal deposition during the late Holocene, and a period of increased deposition potentially linked to the Little Ice Age. In addition, evidence for a high-energy erosion event dated to ~3800 cal yr BP suggest a catastrophic flood event during the middle Holocene that may correlate with volcanic activity at the Craters of the Moon lava fields to the northwest. This study provides a model for the study of alluvial terrace formations in arid environments and their potential to preserve stratified archaeological deposits.

  19. Landscapes of human evolution: models and methods of tectonic geomorphology and the reconstruction of hominin landscapes. (United States)

    Bailey, Geoffrey N; Reynolds, Sally C; King, Geoffrey C P


    This paper examines the relationship between complex and tectonically active landscapes and patterns of human evolution. We show how active tectonics can produce dynamic landscapes with geomorphological and topographic features that may be critical to long-term patterns of hominin land use, but which are not typically addressed in landscape reconstructions based on existing geological and paleoenvironmental principles. We describe methods of representing topography at a range of scales using measures of roughness based on digital elevation data, and combine the resulting maps with satellite imagery and ground observations to reconstruct features of the wider landscape as they existed at the time of hominin occupation and activity. We apply these methods to sites in South Africa, where relatively stable topography facilitates reconstruction. We demonstrate the presence of previously unrecognized tectonic effects and their implications for the interpretation of hominin habitats and land use. In parts of the East African Rift, reconstruction is more difficult because of dramatic changes since the time of hominin occupation, while fossils are often found in places where activity has now almost ceased. However, we show that original, dynamic landscape features can be assessed by analogy with parts of the Rift that are currently active and indicate how this approach can complement other sources of information to add new insights and pose new questions for future investigation of hominin land use and habitats.

  20. Multilevel approach to the geomorphological setting of an alluvial plain in the Alpine environment (United States)

    Minciotti, Nancy A.; Brivio, Pietro A.; Zilioli, Eugenio


    This paper presents an integrated use of cartography and remote sensing imagery supplied by satellite and aircraft to study the geomorphological aspects of an alluvial plain for archaeological purposes. The study area is located at the confluence of the Valtellina (Adda River) and Lower Mera River valleys in northern Italy. Landsat data and aerial photographs were used to study the partial filling of the Lake Como lacustrine basin resulting from the progradation of the Adda River delta. Different soil humidity content, related to variable grain size of the alluvial deposits is an indicator of ancient river beds which were formed in this area before the nineteenth century artificial rectification of the River Adda's final stretch. Profiles coincident with geological sections gained by geophysical sounding were performed on the remote sensing imagery to verify eventual correspondence of depositional features with different analysis techniques. The integration of remote sensing multilevel data with cartography and archaeological evidences has been useful for the assessment of the paleoenvironment which conditioned human settlements.

  1. A geomorphological response of beaches to Typhoon Meari in the eastern Shandong Peninsula in China

    Institute of Scientific and Technical Information of China (English)

    DING Dong; YANG Jichao; LI Guangxue; DADA Olusegun A; GONG Lixin; WANG Nan; WANG Xiangdong; ZHANG Bin


    Eight representative beach profiles on the eastern coast of the Shandong Peninsula are observed and measured in 2011 and 2012 to determine the coastal processes under the lower tropical wind speed condition and the beach response to and recovery from the tropical storm Meari in a rare typhoon region. The results show that it is the enhancement and directional change of cross-shore and longshore sediment transports caused by Meari that leads to the beach morphological changes, and most of the sediment transports occur during the pre-Meari landing phase. The erosional scarp formation and the berm or beach face erosion are the main geomorphological responses of the beaches to the storm. The storm characteristics are more important than the beach shapes in the storm response process of the beaches on Shandong Peninsula. The typhoon is a fortuitous strong dynamic event, and the effect on the dissipative beach is more obvious than it is on the reflective beach in the study region. Furthermore, the beach trend is the main factor that controlls the storm effect intensity, and it is also closely related to the recovery of the beach profiles.

  2. Applying fluvial geomorphological riffle-pool sequences concept when rebuilding the existing drop hydraulic structure

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    Full Text Available The paper deals with the problem of  rebuilding  the existing water straight drop  structure in Brenna on the Brennica river (Polish Carpathian mountains, which was changed into the rapid hydraulic structure. The technical project was set up in 1988 and finished in the same year. The structure was rebuilt in the field in the early autumn of 1990. One of the concepts of applied fluvial geomorphological solution was used to improve the river channel bed condition. In that case it was found that the existing hydraulic structure reducing river slope and stabilizing river bed can be changed without any harm in to semi-natural riffle structure which could be tolerated by river and organisms living in.  Artificial roughness of the slope plate of the rapid hydraulic structure was obtained by placing cobbles along all the slope apron of the structure. The diameter of cobbles was calculated applying various methods, and the optimum value for that dimension was chosen. The cobbles, used for rebuilding purposes, were taken directly from the riverbed, so that the structure is environmentally similar to the site. All work was done due to European Framework Directive for Rivers.

  3. Regional controls on geomorphology, hydrology, and ecosystem integrity in the Orinoco Delta, Venezuela (United States)

    Warne, Andrew G.; Meade, Robert H.; White, William A.; Guevara, Edgar H.; Gibeaut, James; Smyth, Rebecca C.; Aslan, Andres; Tremblay, Thomas


    Interacting river discharge, tidal oscillation, and tropical rainfall across the 22,000 km 2 Orinoco delta plain support diverse fresh and brackish water ecosystems. To develop environmental baseline information for this largely unpopulated region, we evaluate major coastal plain, shallow marine, and river systems of northeastern South America, which serves to identify principal sources and controls of water and sediment flow into, through, and out of the Orinoco Delta. The regional analysis includes a summary of the geology, hydrodynamics, sediment dynamics, and geomorphic characteristics of the Orinoco drainage basin, river, and delta system. Because the Amazon River is a major source of sediment deposited along the Orinoco coast, we summarize Amazon water and sediment input to the northeastern South American littoral zone. We investigate sediment dynamics and geomorphology of the Guiana coast, where marine processes and Holocene history are similar to the Orinoco coast. Major factors controlling Orinoco Delta water and sediment dynamics include the pronounced annual flood discharge; the uneven distribution of water and sediment discharge across the delta plain; discharge of large volumes of water with low sediment concentrations through the Rı´o Grande and Araguao distributaries; water and sediment dynamics associated with the Guayana littoral current along the northeastern South American coast; inflow of large volumes of Amazon sediment to the Orinoco coast; development of a fresh water plume seaward of Boca Grande; disruption of the Guayana Current by Trinidad, Boca de Serpientes, and Gulf of Paria; and the constriction at Boca de Serpientes.

  4. Late Wisconsinan Glacial Geomorphology of the Kent Interlobate Complex, Ohio, USA

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    João Bessa Santos


    Full Text Available The northern sector of the Kent Interlobate Complex, created by twomajor ice lobes of the Laurentide Ice Sheet during late Wisconsinan times, dominates the glacial landscape of northeast Ohio. The geomorphology of this impressive complex reveals the presence of large hummocks, kettle lakes and substantial esker chains. The esker chains,usually smaller than 1.3 km long, run parallel to the interlobate complex geographic orientation of northeast-southwest. Gravel pits present on large hummocks display bedded and sorted sedimentary units of gravel, sand and gravel and climbing ripple laminated sand with folds, which demonstrate that the northern sector of the interlobate complex is primarily a glaciofluvial feature. Topping these hummocks is a massive clast-supported diamicton interpreted to be a debris flow. These geomorphic and sedimentary characteristics seem to indicate that hummocks present in the interlobate area are in fact kames and that the entire northern sector of the interlobate complex is a product of late Wisconsinan time transgressive ice stagnation that occurred between two major ice lobes.

  5. Role of ground water in geomorphology, geology, and paleoclimate of the Southern High Plains, USA. (United States)

    Wood, Warren W


    Study of ground water in the Southern High Plains is central to an understanding of the geomorphology, deposition of economic minerals, and climate change record in the area. Ground water has controlled the course of the Canadian and Pecos rivers that isolated the Southern High Plains from the Great Plains and has contributed significantly to the continuing retreat of the westward escarpment. Evaporative and dissolution processes are responsible for current plateau topography and the development of the signature 20,000 small playa basins and 40 to 50 large saline lake basins in the area. In conjunction with eolian processes, ground water transport controls the mineralogy of commercially valuable mineral deposits and sets up the distribution of fine efflorescent salts that adversely affect water quality. As the water table rises and retreats, lunette and tufa formation provides valuable paleoclimate data for the Southern High Plains. In all these cases, an understanding of ground water processes contributes valuable information to a broad range of geological topics, well beyond traditional interest in water supply and environmental issues.

  6. A geomorphology-based ANFIS model for multi-station modeling of rainfall-runoff process (United States)

    Nourani, Vahid; Komasi, Mehdi


    This paper demonstrates the potential use of Artificial Intelligence (AI) techniques for predicting daily runoff at multiple gauging stations. Uncertainty and complexity of the rainfall-runoff process due to its variability in space and time in one hand and lack of historical data on the other hand, cause difficulties in the spatiotemporal modeling of the process. In this paper, an Integrated Geomorphological Adaptive Neuro-Fuzzy Inference System (IGANFIS) model conjugated with C-means clustering algorithm was used for rainfall-runoff modeling at multiple stations of the Eel River watershed, California. The proposed model could be used for predicting runoff in the stations with lack of data or any sub-basin within the watershed because of employing the spatial and temporal variables of the sub-basins as the model inputs. This ability of the integrated model for spatiotemporal modeling of the process was examined through the cross validation technique for a station. In this way, different ANFIS structures were trained using Sugeno algorithm in order to estimate daily discharge values at different stations. In order to improve the model efficiency, the input data were then classified into some clusters by the means of fuzzy C-means (FCMs) method. The goodness-of-fit measures support the gainful use of the IGANFIS and FCM methods in spatiotemporal modeling of hydrological processes.

  7. Geomorphological and geophysical investigations for the characterization of the Roman Carsulae site (Tiber basin, Central Italy) (United States)

    Bottari, C.; Aringoli, D.; Carluccio, R.; Castellano, C.; D'Ajello Caracciolo, F.; Gasperini, M.; Materazzi, M.; Nicolosi, I.; Pambianchi, G.; Pieruccini, P.; Sepe, V.; Urbini, S.; Varazi, F.


    This paper aims to bring to light the possible linkage between karstic phenomena and the human occupation of the Roman site of Carsulae (Tiber basin, Central Italy). Dolines are a typical morphological expression of karst rocks' dissolution and collapse and, usually, they represent a potential hazard for human activities and, in particular, in the care and maintenance of cultural heritage sites. In this study, we observed that the development of a subsidence doline caused severe damage to some archaeological structures at the Carsulae monumental site. According to the results obtained in our investigation, three sites at least with karst dissolution phenomena in the shallow calcareous tufa layer have been identified. One of them subsided probably in Roman times and produced a sharp deformation of the decumanus. In order to understand the evolution of this territory an integrated geomorphological and geophysical survey was carried out. The combination between the information derived from different geophysical techniques, such as: Electrical Resistivity Tomography (ERT), Frequency-Domain Electromagnetism (FDEM), and Ground Penetrating Radar (GPR) clearly pointed out that the calcareous tufa layer is characterized by an irregular geometry and this resulted in the investigated area being affected by karst dissolution in several parts. Four boreholes opportunely located, provided direct information about the depth and the alteration of the calcareous tufa basement and precious calibration data for the geophysical methods. This study contributes to improving our knowledge on the evolution of the Carsulae archaeological site providing a new insight into the adaptation of ancient human societies in this problematic territory.

  8. A geomorphological approach to the estimation of landslide hazards and risks in Umbria, Central Italy

    Directory of Open Access Journals (Sweden)

    M. Cardinali


    Full Text Available We present a geomorphological method to evaluate landslide hazard and risk. The method is based on the recognition of existing and past landslides, on the scrutiny of the local geological and morphological setting, and on the study of site-specific and historical information on past landslide events. For each study area a multi-temporal landslide inventory map has been prepared through the interpretation of various sets of stereoscopic aerial photographs taken over the period 1941–1999, field mapping carried out in the years 2000 and 2001, and the critical review of site-specific investigations completed to solve local instability problems. The multi-temporal landslide map portrays the distribution of the existing and past landslides and their observed changes over a period of about 60 years. Changes in the distribution and pattern of landslides allow one to infer the possible evolution of slopes, the most probable type of failures, and their expected frequency of occurrence and intensity. This information is used to evaluate landslide hazard, and to estimate the associated risk. The methodology is not straightforward and requires experienced geomorphologists, trained in the recognition and analysis of slope processes. Levels of landslide hazard and risk are expressed using an index that conveys, in a simple and compact format, information on the landslide frequency, the landslide intensity, and the likely damage caused by the expected failure. The methodology was tested in 79 towns, villages, and individual dwellings in the Umbria Region of central Italy.

  9. Trace metals in soils of the main geomorphological units in the southwestern part of Western Siberia (United States)

    Konstantinova, E. Yu


    Total concentrations of Ti, Cr, Mn, Ni, Cu, Zn, Rb, Sr, and Pb as well as soil granulometric texture were studied for three plot sites representing different geomorphologic units of the southwestern part of Western Siberia: periphery of the upland Tobolsky Mainland, Ishim plain, Turinskaya plain. Interregional difference in the relationship by and among the content of trace elements and particle size distribution of soil horizons is established. Thus, for the soils of Turinskaya plain such interrelations are not observed. For the soils of Ishim Plain moderate negative correlation between Pb concentrations and medium silt, as well as average positive correlations between Zn and fine sand, coarse sand and Pb are found. For the soils of the high terraces of the Irtish and periphery of Tobolsky Mainland interface zone moderate positive correlations between contents of Ti, Zn, Sr and fine sand, weak positive ones between Rb and medium sand, moderate negative ones between Zn and clay, Ti, Ni, Cu, Zn, Rb, Sr, and fine dust, Ti, Cu, Zn, Rb, Sr and medium silt are observed. Consequently, properties and genesis of local parent rocks are significant factors for distribution and accumulation of trace elements in the soils of the southern taiga; at the same time, the processes of bioaccumulation in thick humus horizons of dark gray soils and chernozems apparently play an important part in accumulation and migration of trace elements in forest-steppe soils of Ishim and Turinskaya plains.

  10. Geomorphological Dating Using an Improved Scarp Degradation Model: Is This a Reliable Approach Compared With Common Absolute Dating Methods? (United States)

    Oemisch, M.; Hergarten, S.; Neugebauer, H. J.


    Geomorphological dating of a certain landform or geomorphological structure is based on the evolution of the landscape itself. In this context it is difficult to use common absolute dating techniques such as luminescence and radiocarbon dating because they require datable material which is often not available. Additionally these methods do not always date the time since the formation of these structures. For these reasons the application of geomorphological dating seems one reliable possibility to date certain geomorphological features. The aim of our work is to relate present-day shapes of fault scarps and terrace risers to their ages. The time span since scarp formation ceased is reflected by the stage of degradation as well as the rounding of the profile edges due to erosive processes. It is assumed that the average rate of downslope soil movement depends on the local slope angle and can be described in terms of a diffusion equation. On the basis of these assumptions we present a model to simulate the temporal development of scarp degradation by erosion. A diffusivity reflecting the effects of soil erosion, surface runoff and detachability of particles as well as present-day shapes of scarps are included in the model. As observations of present-day scarps suggest a higher diffusivity at the toe than at the head of a slope, we suggest a linear approach with increasing diffusivities in downslope direction. First results show a better match between simulated and observed profiles of the Upper Rhine Graben in comparison to models using a constant diffusivity. To date the scarps the model has to be calibrated. For this purpose we estimate diffusivities by fitting modelled profiles to observed ones of known age. Field data have been collected in the area around Bonn, Germany and in the Alps, Switzerland. It is a matter of current research to assess the quality of this dating technique and to compare the results and the applicability with some of the absolute dating

  11. Changing tidal hydrodynamics during different stages of eco-geomorphological development of a tidal marsh: A numerical modeling study (United States)

    Stark, J.; Meire, P.; Temmerman, S.


    The eco-geomorphological development of tidal marshes, from initially low-elevated bare tidal flats up to a high-elevated marsh and its typical network of channels and creeks, induces long-term changes in tidal hydrodynamics in a marsh, which will have feedback effects on the marsh development. We use a two-dimensional hydrodynamic model of the Saeftinghe marsh (Netherlands) to study tidal hydrodynamics, and tidal asymmetry in particular, for model scenarios with different input bathymetries and vegetation coverages that represent different stages of eco-geomorphological marsh development, from a low elevation stage with low vegetation coverage to a high and fully vegetated marsh platform. Tidal asymmetry is quantified along a 4 km marsh channel by (1) the difference in peak flood and peak ebb velocities, (2) the ratio between duration of the rising tide and the falling tide and (3) the time-integrated dimensionless bed shear stress during flood and ebb. Although spatial variations in tidal asymmetry are large and the different indicators for tidal asymmetry do not always respond similarly to eco-geomorphological changes, some general trends can be obtained. Flood-dominance prevails during the initial bare stage of a low-lying tidal flat. Vegetation establishment and platform expansion lead to marsh-scale flow concentration to the bare channels, causing an increase in tidal prism in the channels along with a less flood-dominant asymmetry of the horizontal tide. The decrease in flood-dominance continues as the platform grows vertically and the sediment-demand of the platform decreases. However, when the platform elevation gets sufficiently high in the tidal frame and part of the spring-neap cycle is confined to the channels, the discharge in the channels decreases and tidal asymmetry becomes more flood-dominant again, indicating an infilling of the marsh channels. Furthermore, model results suggest that hydro-morphodynamic feedbacks based on tidal prism to channel

  12. Use of High Spatial Resolution Remote Sensing for Hydro-Geomorphologic Analysis of Medium-sized Arid Basins (United States)

    Sadeh, Yuval; Blumberg, Dan G.; Cohen, Hai; Morin, Efrat; Maman, Shimrit


    Arid environments are often remote, expansive, difficult to access and especially vulnerable to flash flood hazards due to the poor understanding of the phenomenon and the lack of meteorological, geomorphological, and hydrological data. For many years, catchment characteristics have been observed using point-based measurements such as rain gauges and soil sample analysis; on the other hand, use of remote sensing technologies can provide spatially continuous hydrological parameters and variables. The advances in remote sensing technologies can provide new geo-spatial data using high spatial and temporal resolution for basin-scale geomorphological analysis and hydrological models. This study used high spatial resolution remote sensing for hydro-geomorphologic analysis of the arid medium size Rahaf watershed (76 km2), located in the Judean Desert, Israel. During the research a high resolution geomorphological map of Rahaf basin was created using WorldView-2 multispectral satellite imageries; surface roughness was estimated using SIR-C and COSMO-SkyMed Synthetic Aperture Radar (SAR) spaceborne sensors; and rainstorm characteristics were extracted using ground-based meteorological radar. The geomorphological mapping of Rahaf into 17 classes with good accuracy. The surface roughness extraction using SAR over the basin showed that the correlation between the COSMO-SkyMed backscatter coefficient and the surface roughness was very strong with an R2 of 0.97. This study showed that using x-band spaceborne sensors with high spatial resolution, such as COSMO-SkyMed, are more suitable for surface roughness evaluation in flat arid environments and should be in favor with longer wavelength operating sensors such as the SIR-C. The current study presents an innovative method to evaluate Manning's hydraulic roughness coefficient (n) in arid environments using radar backscattering. The weather radar rainfall data was calibrated using rain gauges located in the watershed. The

  13. Stochastic Geomorphology: Indexing Climate Change Through Shifts in Probability Densities of Erosion, Sediment Flux, Storage and Habitats (United States)

    Benda, L. E.


    Stochastic geomorphology refers to the interaction of the stochastic field of sediment supply with hierarchically branching river networks where erosion, sediment flux and storage are described by their probability densities. The conceptual and numerical framework can generate a series of general principles (hypotheses) on how basin-scale erosion and sedimentation regimes, viewed through the lens of probability distributions, change with variations in climate, topography, geology, vegetation, basin scale, and network topology; for more detail on the general principles see AGU session EP02. The conceptual and numerical framework of stochastic geomorphology is well suited for forecasting and interpreting affects of climate change on geomorphological systems, including the habitats associated with them. Climate change involves shifts in probability distributions of precipitation (rain and snow), fires, and wind. Consequently, shifts in distributions of precipitation frequency and magnitude or wildfire frequency, intensity and size should lead to shifts in erosion, sediment flux and sedimentation distributions. Shifts could include either a greater or lesser skew of their attendant probability densities. For example, increasing the frequency of fires in a stochastic simulation model of erosion and sedimentation will lead to altered frequency and magnitude of hillslope erosion in the form of pulses of sediment through the river network. This will be reflected in shifts in the probability densities of erosion and sedimentation and also how sediment flux and storage distributions evolve downstream in river networks. Heightened erosion frequency and magnitude due to climate change can increase Hurst Effects in time series of sediment flux and thus an increase in depletion of hillslope stores of sediment can result in temporally lingering sedimentation affects throughout river networks, even if climate relaxed to pre-change conditions. Similarly, heightened hillslope

  14. Fluvial dissection, isostatic uplift, and geomorphological evolution of volcanic islands (Gran Canaria, Canary Islands, Spain) (United States)

    Menéndez, Inmaculada; Silva, Pablo G.; Martín-Betancor, Moises; Pérez-Torrado, Francisco José; Guillou, Hervé; Scaillet, S.


    Digital analysis of torrential gullies ('barrancos') deeply incised into the volcanic Island of Gran Canaria (Canary Islands) allows us to extract the longitudinal profiles and pre-incision surfaces for individual basins, from which morphometric parameters (length, elevation, area, slope) have been calculated. Other derived parameters, such as ridgeline profiles, maximum incision values, volume removed by fluvial erosion, geophysical relief and isostatic uplift, have also been computed. Based on K/Ar ages for the island, well-constrained incision-uplift rates have been calculated by means of the combination of different methodological approaches commonly used in orogens and large mountain ranges. The geomorphological and morphometric analyses reveal that the island is clearly divided into four environmental quadrants determined by the combination of a couple of key-factors: the age of the volcanic surfaces and the climatic conditions. These factors determine a young sector covered with Plio-Quaternary platform-forming lavas (finished at 1.9-1.5 Ma) evolving under contrasting wet (NE) to dry (SE) climates, and an older sector, conserving the residual surfaces of the Miocene shield building (14.5-8.7 Ma) at the ridgelines, also subjected to wet (NW) and dry (SW) climates. Incision is related to the age zonation of the island. Maximum incisions (< 1200 m) are logically recorded in the older SW sector of the island, but incision rates are directly related to the climatic zonation, with maximum mean values in the wet Northern quadrants (0.18-0.12 mm/yr). The evaluation of the material removed by fluvial erosion for individual basins allows us to assess the consequent theoretical isostatic response in the different sectors of the island. The obtained uplift rates indicate that water availability (by drainage area and elevation) is a relevant controlling factor: the records from the wet Northern sectors show uplift values of between 0.09 and 0.03 mm/yr, whereas in the

  15. Challenges for a cross-disciplinary geoarchaeology: The intersection between environmental history and geomorphology (United States)

    Butzer, Karl W.


    Geoarchaeology is a growing subfield of cross-disciplinary research at the intersection between geomorphology, environmental history, and archaeology. This prospective essay does not aim to analyze the nature or evolution of geoarachaeology, or to review available techniques and methods. Instead it addresses challenges. Exciting challenges confront geoarchaeology in the form of persistent problems that demand satisfactory solutions, despite improving skills and innovative technologies. Drawing from the full record of human history, a number of practical issues can be highlighted to explicate these challenges: Open-air archaeological sites are the main object of study for the Early to Mid-Pleistocene, even though they represent open systems that raise fundamental questions about archaeo-taphonomic integrity. How were sites buried and then modified by selective preservation, horizontal or vertical disturbance, and the role of carnivores? Is it possible to determine the degree to which such sites accurately record prehistoric human behavior, prior to the Late Pleistocene when hearths and living structures lend better definition to occupation surfaces? Can non-primary open-air sites also shed light on human activities and environmental history? Cave sites have long been favored by archaeologists because of the impression that they represent relatively complete and undisturbed archaeostratigraphic sequences. But serious problems also exist here in regard to the nature of accumulation and the sources of mineral and biogenic sediments in what were open systems, liable to disturbance, despite comparatively low-energy processes. Less familiar are urban and other architectural sites, where processes of formation and degradation mimic natural sedimentation and erosion. Such a geoarchaeology can be highly informative for urban processes, demographic cycles, or the intersection between sites and their surrounding landscapes. Spatial components of geoarchaeological research need

  16. Clipperton Atoll (eastern Pacific): oceanography, geomorphology, reef-building coral ecology and biogeography (United States)

    Glynn, P. W.; Veron, J. E. N.; Wellington, G. M.


    Coral reef geomorphology and community composition were investigated in the tropical northeastern Pacific during April 1994. Three areas were surveyed in the Revillagigedo Islands (Mexico), and an intensive study was conducted on Clipperton Atoll (1,300 km SW of Acapulco), including macro-scale surface circulation, sea surface temperature (SST) climatology, geomorphology, coral community structure, zonation, and biogeography. Satellite-tracked drifter buoys from 1979 1993 demonstrated complex patterns of surface circulation with dominantly easterly flow (North Equatorial Counter Current, NECC), but also westerly currents (South Equatorial Current, SEC) that could transport propagules to Clipperton from both central and eastern Pacific regions. The northernmost latitude reached by the NECC is not influenced by El Niño-Southern Oscillation (ENSO) events, but easterly flow velocity evidently is accelerated at such times. Maximum NECC flow rates indicate that the eastern Pacific barrier can be bridged in 60 to 120 days. SST anomalies at Clipperton occur during ENSO events and were greater at Clipperton in 1987 than during 1982 1983. Shallow (15 18 m)and deep (50 58 m) terraces are present around most of Clipperton, probably representing Modern and late Pleistocene sea level stands. Although Clipperton is a well developed atoll with high coral cover, the reef-building fauna is depauperate, consisting of only 7 species of scleractinian corals belonging to the genera Pocillopora, Porites, Pavona and Leptoseris, and 1 species of hydrocoral in the genus Millepora. The identities of the one Pocilpopora species and one of the two Porites species are still unknown. Two of the remaining scleractinians ( Pavona minuta, Leptoseris scabra) and the hydrocoral ( Millepora exaesa), all formerly known from central and western Pacific localities, represent new eastern Pacific records. Scleractinian corals predominate (10 100% cover) over insular shelf depths of 8 to 60m, and crustose

  17. Impact of periglacial and paraglacial processes on rocky coast geomorphology in Arctic and Antarctic (United States)

    Strzelecki, Matt; Lim, Michael; Kasprzak, Marek; Swirad, Zuzanna; Rachlewicz, Grzegorz; Pawlowski, Lukasz; Jaskolski, Marek; Migon, Piotr


    In contrast to mid and low latitude coasts, relatively little is known regarding the potential impacts of climate and sea-level change on polar coastal margins. Indeed, many of the existing intellectual paradigms regarding the functioning of polar coasts are now out-dated, based on descriptive geomorphology and a limited process-based understanding. Our work aims to address this deficiency in understanding by quantifying the processes controlling the evolution and behaviour of rock coasts in polar climates, based on representative examples from South Shetland Islands (Antarctic) and Svalbard (Arctic). The pristine coasts of South Shetland Islands and Svalbard provide a superb opportunity to quantify how polar rock coasts are responding to sea-level changes and intensification of periglacial and paraglacial processes associated with climate warming. The selected coastline forms part of the South Shetland and Svalbard strandflat, which is characterized by diverse range of coastal landforms. The rock cliffs and shore platforms in selected study sites are formed in volcanic rocks (Antarctic) and divers mixture of sedimentary and crystalline formations (Svalbard). In our project we utilise a rigorous, coherent and novel suite of techniques to analyse the spatially and temporally diverse range of processes and responses controlling the polar rock coast environments: -Schmidt Hammer and Equotip tests of rock surface resistance -micro-erosion meter measurements of rock surface downwearing rates -observations of seasonal changes in the state of permafrost developed in solid rocks using electrical resistivity tomography (ERT) -monitoring of thermal state of the rocky cliffs and platforms using network of thermistors -photogrammetric analysis of digital images of scanned cliffs and platforms and GIS processing of obtained data In this paper we present the results of field campaigns of the project carried out in years 2014-2016 in Admiralty Bay (South Shetland) and Hornsund

  18. Digital mono- and 3D stereo-photogrammetry for geological and geomorphological mapping (United States)

    Scapozza, Cristian; Schenker, Filippo Luca; Castelletti, Claudio; Bozzini, Claudio; Ambrosi, Christian


    corresponding real world pixel on the DEM, and then extract georeferenced vector data and orthorectified raster data from terrestrial photographs (Bozzini et al., 2012; Scapozza et al., 2014). Through some case studies, we show (1) how 3D digital stereo-photogrammetry makes it possible the production of Quaternary geological and geomorphological maps, (2) how digital mono-photogrammetry is a powerful tool for supporting geological mapping in very steep zones and (3) how the combination of these two digital tools permits diachronical mapping of phenomena evolution (such as landslides or rockglaciers) during the entire twentieth century. Ambrosi C. and Scapozza C. 2015. Improvements in 3-D digital mapping for geomorphological and Quaternary geological cartography. Geographica Helvetica 70: 121-133. doi: 10.5194/gh-70-121-2015 Bozzini C., Conedera M. and Krebs P. 2012. A new monoplotting tool to extract georeferenced vector data and orthorectified raster data from oblique non-metric photographs. International Journal of Heritage in the Digital Era 1: 499-518. doi: 10.1260/2047-4970.1.3.499 Scapozza C., Lambiel C., Bozzini C., Mari S. and Conedera M. 2014. Assessing the rock glacier kinematics on three different timescales: a case study from the southern Swiss Alps. Earth Surface Processes and Landforms 39: 2056-2069. doi: 10.1002/esp.3599

  19. An overview of the surface and near-surface geology, geomorphology and natural resources of Kuwait (United States)

    Al-Sulaimi, J.; Mukhopadhyay, A.


    The surface and near-surface geology, geomorphology and natural resources of Kuwait have been reviewed based on the published work. The stratigraphy and structure of the near-surface sediments of Kuwait have been mainly controlled by the Tertiary tectonic activity of the Arabian Shield. The shield started separating from the African mainland by the close of the Eocene and drifted northeastward towards the Asian plate, giving rise to the folding and thrusting of the Zagros Mountains of Iran. The tectonic activity superimposed a northwest-southeast trend over an earlier north-south structural trend, and gave rise to parallel ridges and valleys trending northwest-southeast through differential erosion. It has been possible to identify 15 geomorphic zones and 11 morphostructures from analysis of the surface features of Kuwait. Seven of these morphostructures can be attributed to tectonic processes and two to fluvial processes. It has not been possible, however, to explain satisfactorily the origin of the Jal Az-Zor escarpment or the Ad-Dalmaniyah cliff. The whole of Kuwait can be divided into seven drainage zones. Of these, the internal drainage systems of the Ar-Raudhatain-Umm Al-Aish drainage system and the Ad-Dibdibba drainage system are hydrogeologically most important. The clastic deposits of Kuwait Group sediments, often affected by low-temperature carbonate (calcite and dolomite) and sulfate (gypsum) precipitation, form the surface rock of Kuwait. These are covered by recent aeolian and residual deposits; playa deposits in the enclosed basins; and near the coast, oolitic sediments, beach sands and sabkha deposits. The surface and near-surface deposits of Kuwait contain important reserves of construction sand and gravel as well as the only naturally occurring freshwater reserves of the country. An understanding of the nature of these surface deposits is required for the management of environmental issues like sand encroachment, land-use planning, and soil and

  20. Combining meteorological and geomorphological expertise to provide better evidences of changes in rainfall precipitation extremes (United States)

    Grazzini, Federico; Segadelli, Stefano; Chelli, Alessandro


    Three extreme intensity precipitation events have been stricken the hilly and mountainous territory of Emilia-Romagna Region (Italy) in the last 4 years. Major effects on the ground were observed: i.e. debris flows, shallow landslides, flash floods and overbank flooding. Some of them (like debris flow) are considered unusual, on such large scale, for this region. Though a detailed meteorological and geomorphological analyses of the last and most devastating event, occurred in Val Trebbia and Nure in September 2015, we show the value of this multidisciplinary analysis conducted in collaboration between the HydroMeteorological service of Emilia-Romagna (ARPAE-SIMC) and the Geological, Sismic and Soil service of the same region (SGSS) and Parma University. A large and stationary mesoscale convective system released more than 300 mm of rain, roughly, in 6 hours. During the first part of the storm, several rain gauges recorded rainfall peaks over 100 mm/hr. The storm caused more than 100 debris flows that were the main cause of damage on man-made structures. A robust quantitative relation between precipitation intensity (estimated trough a combination of radar data and rain gouges) and comprehensive mapping of airborne and satellite imageries acquired by the Emergency Management Service (Copernicus), complemented by fieldwork of geologists, could be built from this event. This accurate analysis, in a particularly rich data area, set an important reference point to search past events of similar amplitude, beyond the short chronological history of observation records of sub-daily precipitation intensity. We will describe in fact how we plan to gain further insights investigating in situ geological records to find analogous high intensity rain effects.

  1. Geochronological (OSL) and geomorphological investigations at the presumed Frankfurt ice marginal position in northeast Germany (United States)

    Hardt, Jacob; Lüthgens, Christopher; Hebenstreit, Robert; Böse, Margot


    The Weichselian Frankfurt ice marginal position in northeast Germany has been critically discussed in the past owing to weak morphological evidence and a lack of clear sedimentological records. This study aims to contribute to this discussion with new geochronological and geomorphological results. Apart from very few cosmogenic exposure ages, the time frame is to date still based on long distance correlation with radiocarbon chronologies. We selected a study site in a key position regarding the classic location of the Frankfurt ice marginal position and the recently described arcuate ridge structures on the Barnim plateau. For the first time we present Optically Stimulated Luminescence (OSL) ages of quartz from glaciofluvial deposits for this Weichselian phase. Our results indicate an advance of the Scandinavian Ice Sheet (SIS) at around 34.1 ± 4.6 ka. This is in agreement with OSL ages from sandur deposits at the Brandenburg ice marginal position located farther south and could also be correlated with the Klintholm advance in Denmark. The subsequent meltdown phase lasted until around 26.3 ± 3.7 ka. During the meltdown phase a minor oscillation of the SIS caused the formation of the recently described arcuate ridges on the Barnim till plain. Recalculated surface exposure ages of glacigenic boulders with an updated global production rate indicate a landscape stabilization phase at around 22.7 ± 1.6 ka, which is in agreement with our ages. A phase of strong aeolian activity has been dated with OSL to 1 ± 0.1 ka; this may have been triggered by human activities that are documented in this region for the medieval period.

  2. The evolutionary process of the geomorphology of tidal embayments in southern Jiaodong Peninsula, China (United States)

    Zhan, Chao; Yu, Junbao; Wang, Qing; Li, Yunzhao; Zhou, Di; Xing, Qinghui; Chu, Xiaojing


    Based on the theory of flood/ebb asymmetry, the evolution of the geomorphology of representative bays along the southern coast of the Jiaodong Peninsula over the last 40 years was investigated using remote sensing and geographic information system technologies. The results showed that coastal features such as tidal flats and tidal inlets in the bays changed significantly over time. The studied bays are in a ring-shaped geomorphic spatial pattern characterized by shallow water, and they were concentrically ringed by tidal flats and coastal plains before the early 1980s. Later, however, a number of ponds appeared between the coastal plains and tidal flats. The extent of sediment infill for each bay in the 1980s was greater than that in the 1970s. The conversion of flat-inlets and the erosion/deposition change of tidal inlets in these four bays during study period were not synchronized. Each bay was in a state of flood asymmetry, and both the net fine and net coarse sediment deposition took place in the 1970s. From the late 1960s to the early 1980s, Dingzi Bay was characterized by flood asymmetry, and its tidal asymmetry ratio increased. The Jinghai and the Wuleidao bays were in a state of flood asymmetry, and their tidal asymmetry ratios decreased, while Rushan Bay was in a transition state from flood to ebb asymmetry. However, intensive human activities over the last 30 years, especially the construction of coastal ponds, has greatly changed the hydrology and sedimentation of these bays, causing profound changes in geomorphic features; furthermore, these changes have guided the evolutionary process of the bays. Our results suggest that the intensive human activities were key factors that caused changes in the geomorphic evolution of the studied tidal embayments, especially the sudden change from a state of rising flood asymmetry to ebb asymmetry in Dingzi Bay.

  3. Geomorphological Mapping with Terrestrial Laser Scanning and Uav-Based Imaging (United States)

    Tilly, N.; Kelterbaum, D.; Zeese, R.


    High-resolution digital elevation models (DEMs) are useful for the detailed mapping of geomorphological features. Nowadays various sensors and platforms are available to collect 3D data. The presented study compares terrestrial laser scanning (TLS) and low-cost unmanned aerial vehicles (UAV)-based imaging in terms of their usability for capturing small-scale surface structures. In October 2014 and June 2015 measurements with both systems were carried out in an episodically water-filled karst depression under pasture farming in the region of Hohenlohe (Southwest Germany). The overall aims were to establish high-resolution DEMs and monitor changes of the relief caused by dissolution and compare the advantages and drawbacks of both systems for such studies. Due to the short time between the campaigns the clear detection of temporal changes was hardly possible. However, the multi-temporal campaigns allowed an extensive investigation of the usability of both sensors under different environmental conditions. In addition to the remote sensing measurements, the coordinates of several positions in the study area were measured with a RTK-DGPS system as independent reference data sets in both campaigns. The TLS- and UAV-derived DEM heights at these positions were validated against the DGPS-derived heights. The accuracy of the TLS-derived values is supported by low mean differences between TLS and DGPS measurements while the UAV-derived models show a weaker performance. In the future years additional simultaneous measurements with both approaches under more similar vegetation conditions are necessary to detect surface movements. Moreover, by investigating the subsurface the interaction of above and below ground processes might be detected.

  4. Hydrodynamics, vegetation transition and geomorphology coevolution in a semi-arid floodplain wetland. (United States)

    Sandi, Steven; Rodriguez, Jose F.; Saco, Patricia M.; Riccardi, Gerardo; Wen, Li; Saintilan, Neil


    The Macquarie Marshes is a complex system of marshes, swamps and lagoons interconnected by a network of streams in the semi-arid region in north western NSW, Australia. The low-gradient topography of the site leads to channel breakdown processes where the river network becomes practically non-existent. As a result, the flow extends over large areas of wetland that later re-join and reform channels exiting the system. Vegetation in semiarid wetlands are often water dependent and flood tolerant species that rely on periodical floods in order to maintain healthy conditions. The detrimental state of vegetation in the Macquarie Marshes over the past few decades has been linked to decreasing inundation frequencies. Spatial distribution of flood tolerant overstory species such as River Red Gum and Black Box has not greatly changed since early 1990's, however; the condition of the vegetation patches shows a clear deterioration evidenced by terrestrial species encroachment on the wetland understory. On the other hand, areas of flood dependent species such as Water Couch and Common Reed have undergone complete succession to terrestrial species and dryland. In order to simulate the complex dynamics of the marshes we have developed an ecogeomorphological modelling framework that combines hydrodynamic, vegetation and channel evolution modules and in this presentation we provide an update on the status of the model. The hydrodynamic simulation provides spatially distributed values of inundation extent, duration, depth and recurrence to drive a vegetation model based on species preference to hydraulic conditions. It also provides velocities and shear stresses to assess geomorphological changes. Regular updates of stream network, floodplain surface elevations and vegetation coverage provide feedbacks to the hydrodynamic model. We presents also the development and assessment of transitional rules to determine if the water conditions have been met for different vegetation

  5. Permafrost and climate in Europe: Monitoring and modelling thermal, geomorphological and geotechnical responses (United States)

    Harris, Charles; Arenson, Lukas U.; Christiansen, Hanne H.; Etzelmüller, Bernd; Frauenfelder, Regula; Gruber, Stephan; Haeberli, Wilfried; Hauck, Christian; Hölzle, Martin; Humlum, Ole; Isaksen, Ketil; Kääb, Andreas; Kern-Lütschg, Martina A.; Lehning, Michael; Matsuoka, Norikazu; Murton, Julian B.; Nötzli, Jeanette; Phillips, Marcia; Ross, Neil; Seppälä, Matti; Springman, Sarah M.; Vonder Mühll, Daniel


    understanding of geomorphological process-response systems and their impacts on human activity.

  6. A geomorphology-based approach for digital elevation model fusion - case study in Danang city, Vietnam (United States)

    Tran, T. A.; Raghavan, V.; Masumoto, S.; Vinayaraj, P.; Yonezawa, G.


    Global digital elevation models (DEM) are considered a source of vital spatial information and find wide use in several applications. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Global DEM (GDEM) and Shuttle Radar Topographic Mission (SRTM) DEM offer almost global coverage and provide elevation data for geospatial analysis. However, GDEM and SRTM still contain some height errors that affect the quality of elevation data significantly. This study aims to examine methods to improve the resolution as well as accuracy of available free DEMs by data fusion techniques and evaluating the results with a high-quality reference DEM. The DEM fusion method is based on the accuracy assessment of each global DEM and geomorphological characteristics of the study area. Land cover units were also considered to correct the elevation of GDEM and SRTM with respect to the bare-earth surface. The weighted averaging method was used to fuse the input DEMs based on a landform classification map. According to the landform types, the different weights were used for GDEM and SRTM. Finally, a denoising algorithm (Sun et al., 2007) was applied to filter the output-fused DEM. This fused DEM shows excellent correlation to the reference DEM, having a correlation coefficient R2 = 0.9986, and the accuracy was also improved from a root mean square error (RMSE) of 14.9 m in GDEM and 14.8 m in SRTM to 11.6 m in the fused DEM. The results of terrain-related parameters extracted from this fused DEM such as slope, curvature, terrain roughness index and normal vector of topographic surface are also very comparable to reference data.

  7. Outer shelf seafloor geomorphology along a carbonate escarpment: The eastern Malta Plateau, Mediterranean Sea (United States)

    Micallef, Aaron; Georgiopoulou, Aggeliki; Mountjoy, Joshu; Huvenne, Veerle A. I.; Iacono, Claudio Lo; Le Bas, Timothy; Del Carlo, Paola; Otero, Daniel Cunarro


    Submarine carbonate escarpments, documented in numerous sites around the world, consist of thick exposures of Mesozoic shallow water carbonate sequences - primarily limestones and dolomites - with reliefs of >1 km and slope gradients of >70°. Whilst most research efforts have focused on the processes that shaped carbonate escarpments into complex and extreme terrains, little attention has been paid to the geomorphology of shelves upslope of carbonate escarpments. In this study we investigate high resolution geophysical, sedimentological and visual data acquired from the eastern Malta Plateau, central Mediterranean Sea, to demonstrate that the outer shelf of a carbonate escarpment is directly influenced by escarpment-forming processes. We document forty eight erosional scars, six long channels and numerous smaller-scale channels, three elongate mounds, and an elongate ridge across the eastern Malta Plateau. By analysing their morphology, seismic character, and sedimentological properties, we infer that the seafloor of the eastern Malta Plateau has been modified by three key processes: (i) Mass movements - in the form of translational slides, spreading and debris flows - that mobilised stratified Plio-Pleistocene hemipelagic mud along the shelf break and that were likely triggered by seismicity and loss of support due to canyon erosion across the upper Malta Escarpment; (ii) NNW-SSE trending sinistral strike-slip deformation in Cenozoic carbonates - resulting from the development of a mega-hinge fault system along the Malta Escarpment since the Late Mesozoic, and SE-NW directed horizontal shortening since the Late Miocene - which gave rise to NW-SE oriented extensional grabens and a NNW-SSE horst; (iii) Flow of bottom currents perpendicular and parallel to the Malta Escarpment, associated with either Modified Atlantic Water flows during sea level lowstands and/or Levantine Intermediate Water flows at present, which was responsible for sediment erosion and deposition

  8. The effects of hydraulics, geomorphology, and storm events on metabolism rates in an agricultural river (United States)

    O'Connor, B. L.; Harvey, J. W.; McPhillips, L. E.


    Physical factors such as discharge, geomorphology, and sediment transport strongly influence metabolism rates in agricultural rivers with sparse tree canopies where sunlight is not limiting. These physical processes establish a mosaic of sediment habitats of varying particle sizes, permeabilities, and biological communities that control primary production and respiration rates. In this study, we examined the combined factors of hydraulic conditions, sediment texture, and hyporheic exchange on the spatial and temporal variability of metabolism rates in an agricultural river located in central Iowa. Hydraulic conditions were quantified using field velocity measurements and two-dimensional hydraulic modeling. Sediment texture was assessed using a grid-based survey identifying dominant particle size classes, as well as aerial coverage of green algae and fine benthic organic material. Hyporheic exchange potential was quantified using an effective diffusion scaling relationship based on sediment and flow conditions. Patch-scale metabolism rates varied spatially according to patterns in hydraulic and sediment characteristics, but were of the same order of magnitude as reach-scale gross primary productivity and community respiration measurements. Two discharge-related storm perturbation regimes to the reach-scale metabolism rates were identified using diurnal dissolved oxygen data measured at the study reach over three years. Rainfall events of days as a result of increased turbidity, whereas rainfall events of > 3 cm disrupted metabolism rates for several days to weeks due to bed mobilization and the restructuring of the sediment habitats. A combination of hydraulic modeling, habitat mapping, and reach-scale metabolism measurements were used to produce a two-dimensional analysis of a turbidity-related disturbance event that occurred in late fall 2007. Results from this study suggest that physical processes establish, destroy, and restructure hydraulic and sediment

  9. Key Concepts in Geomorphology - NSF supports community-based creation of a new style of textbook (United States)

    Bierman, P. R.; Montgomery, D. R.; Massey, C. A.


    Using support from the National Science Foundation, we have created an all new textbook that differs from existing books and serves as a model for extensive community involvement and vetting at all stages from initial outlining through chapter development and revision to final review. The new textbook is designed to serve undergraduate students in first year courses about Earth Surface Processes, Physical Geography, and Quaternary Geology. The approach we employed to create this book could easily be adapted to creating books in other disciplines. The new textbook differs from existing books because it is shorter and focuses on the key concepts of the discipline rather than on specific derivations or place-based examples. A series of >200 electronic resources developed by community members as part of this project ( provide more detail and geographically specific case-studies that faculty and students need for place-or content-based teaching and learning. NSF support provided for extensive review to ensure accuracy and completeness. Each chapter was reviewed at least twice by two experts in the chapter's content area. Every chapter was also vetted by 8 to 10 generalist reviewers before extensive copyediting. The entire textbook was edited by two senior geomorphologists and a technical editor with expertise in geomorphology. The textbook has 14 chapters organized into four sections. Each chapter includes between 10 and 14 newly drafted, full-color figures designed specifically for novice learners. Between 20 and 30 annotated color photographs illustrate each of the chapters. At the end of each chapter, the Digging Deeper section presents an in depth look at the development of scientific thought on a problem relevant to the chapter along with a worked problem and a series of questions that allow students to test their mastery of the material.

  10. GIS-supported geomorphological landslide hazard analysis in the Lainbach catchment, Upper Bavaria (United States)

    Trau, J.; Ergenzinger, P.


    The Lainbach basin is located at the fringe of the Northern Limestone Alps. Predominant mass movements such as translational and rotational slides as well as debris flows are mainly linked to glacial deposits (Pleistocene valley fill) and Flysch series covering approximately 50% of the basin. The pre-Pleistocene relief is buried to a maximum thickness of 170 m of till, glacio-limnic and glacio-fluvial sediments. The spatial and temporal distributions of mass movements are coupled with different stages of fluvial incision. Recent fluvial processes are mainly bedrock controlled in the lower reaches. A special geomorphological map at a scale of 1:10.000 illustrates the relief evolution. In addition, the map focuses on past and recent process-forms related to mass movements. Thus areas of active and inactive mass movements can be easily distinguished. Zones of activity and the hazard potential can be deduced from the map. Hazard assessment is supported by GIS modelling, DEM analysis, multi-temporal time series analysis and aerial photo interpretation. Geophysical soundings are important for detailed site specific information such as shear planes and sediment thickness. A GIS model based on the parameters geology, topography (slope angle, curvature), thickness of loosely-consolidated material, vegetation and hydrology (proximity to receiving stream) was developed. Calculation of failure rates allow a specific value to be assigned to each parameter class indicating its role in the mass movement process. About 90% of the mapped mass movements were correctly classified by the model. Although the overall match seems to be quite good there are some localities where the modelled and the mapped results differ significantly. In the future, the mapped results should be considered together with further “expert knowledge” for an improvement of the GIS model.

  11. Deglacial history of the Pensacola Mountains, Antarctica from glacial geomorphology and cosmogenic nuclide surface exposure dating (United States)

    Bentley, M. J.; Hein, A. S.; Sugden, D. E.; Whitehouse, P. L.; Shanks, R.; Xu, S.; Freeman, S. P. H. T.


    The retreat history of the Antarctic Ice Sheet is important for understanding rapid deglaciation, as well as to constrain numerical ice sheet models and ice loading models required for glacial isostatic adjustment modelling. There is particular debate about the extent of grounded ice in the Weddell Sea embayment at the Last Glacial Maximum, and its subsequent deglacial history. Here we provide a new dataset of geomorphological observations and cosmogenic nuclide surface exposure ages of erratic samples that constrain the deglacial history of the Pensacola Mountains, adjacent to the present day Foundation Ice Stream and Academy Glacier in the southern Weddell Sea embayment. We show there is evidence of at least two glaciations, the first of which was relatively old and warm-based, and a more recent cold-based glaciation. During the most recent glaciation ice thickened by at least 450 m in the Williams Hills and at least 380 m on Mt Bragg. Progressive thinning from these sites was well underway by 10 ka BP and ice reached present levels by 2.5 ka BP, and is broadly similar to the relatively modest thinning histories in the southern Ellsworth Mountains. The thinning history is consistent with, but does not mandate, a Late Holocene retreat of the grounding line to a smaller-than-present configuration, as has been recently hypothesized based on ice sheet and glacial isostatic modelling. The data also show that clasts with complex exposure histories are pervasive and that clast recycling is highly site-dependent. These new data provide constraints on a reconstruction of the retreat history of the formerly-expanded Foundation Ice Stream, derived using a numerical flowband model.

  12. Geology, geomorphology and hydrology of the Wadi Gaza catchment, Gaza Strip, Palestine (United States)

    Zaineldeen, Usama; Aish, Adnan


    The geological, geomorphological and hydrological features along the course of the Wadi Gaza (Palestine) are discussed. The study confirms the existence of Pleistocene loess sediments along the Wadi. Wadi Gaza is characterized by meandering features along its course. The watershed of Wadi Gaza is estimated to cover more than 3500 km2 of the Northern Negev Desert and the Hebron Mountains as well as the small catchment sub-area in the Gaza Strip itself. Storm water drains the hills and mountains of Hebron and the northern Negev desert, accumulates in the Beer-Sheva area, crosses the Gaza Strip and discharges into the Mediterranean Sea. In winter the Wadi Gaza brings about 20 million cubic meter of rainwater into the area. Field investigations demonstrate the existence of loess sediments in the Wadi Gaza area, deposited during the dry periods that affected the area during the Pleistocene. The Digital Elevation Model (DEM) applied for the Gaza Strip confirmed the existence of three Kurkar ridges within the Gaza Strip. Arranged from west to east (i) Sheikh Ejlin Ridge extends up to the current coastline in the west, (ii) Al Montar Ridge occurs near the armistice line in the east and (iii) Bait Hanon Ridge of which a part is present to the northeast of the Gaza Strip and a part to the east of the armistice line (the intermediate part not being accessible for observation due to political reasons. It is considered as a security zone). All three ridges are running NE-SW, parallel to the Mediterranean coastline.

  13. Rock-avalanche geomorphological and hydrological impact on an alpine watershed (United States)

    Frattini, P.; Riva, F.; Crosta, G. B.; Scotti, R.; Greggio, L.; Brardinoni, F.; Fusi, N.


    Rock avalanches are large flow-like movements of fragmented rock that can cause extensive and rapid topographic changes, for which very few quantitative data are available. This paper analyses the geomorphological and hydrological impact of the 3 million m3 Thurwieser rock avalanche (2004, Italian Central Alps) by using Terrestrial Laser Scanner, airborne Lidar and GNSS data collected from 2005 to 2014. Sediment yield with respect to the normal valley regime, the dynamic and mass balance of affected glaciers, and the reorganization of superficial and groundwater flow networks are quantified. In the middle portion of the avalanche deposit, a natural sediment trap collected sediments from a new stream channel developed along the upper portion of the deposit and from a lateral drainage basin. This made possible to assess the 10-year impact of the rock avalanche on the sediment yield, which increased from about 120 to about 400 t km- 2·a- 1. The rock avalanche partially covered a glacier with a shallow debris layer that acted as a thermal insulator, limiting ice ablation and producing a 10-m high scarp between the free surface of the glacier and the debris-covered portion. A reduction of 75% of ice ablation was observed due to thermal insulation. The rock avalanche filled a tributary valley, splitting the original drainage basin in two. Under ordinary flows, seepage occurs within the avalanche deposit along the old valley axis. During high flow conditions, a new stream channel is activated along the middle and lower margin of the deposit, which has produced a new alluvial fan on the main valley floor. The fan evolution is described up to the present volume of about 2000 m3.

  14. Temporal development of vegetation and geomorphology in a man-made beach-dune system by natural processes

    DEFF Research Database (Denmark)

    Vestergaard, Peter


    and life form dynamics, characteristic for primary succession on sandy coasts. A gradual change in species composition of the permanent plots, which appeared by a DCA analysis, could by using TWINSPAN be structured into four groups or plant communities, which reflect succession as well as zonation. Two...... with F. rubra and the invasive alien Rosa rugosa. It was concluded, that the main trends in the geomorphological and vegetational development of the man-made beach-dune system is similar to the development in natural dunes. In the future, further accretion and seaward dune formation may be expected...

  15. Geomorphological map and preliminary analysis of Quaternary sediments in the Planica-Tamar valley (Julian Alps, NW Slovenia) (United States)

    Novak, Andrej; Šmuc, Andrej


    The Planica-Tamar valley is located in the Julian Alps in north-west Slovenia. The Planica-Tamar valley represents typical mountain glacial valley bounded by steep, mainly carbonate cliffs with some glacial deposits still preserved. The valley is currently being filled with numerous Holocene sediments deposited by rock falls, landslides, mass gravity flows and fluvial flows. These deposits are forming active or inactive interfingering talus slopes, alluvial and debris-flow fans, all of them with a complex history of sedimentation and erosion forming unconformity bounded sedimentary units. In order to make a thorough analysis of these deposits a detailed geomorphological map in a scale of 1:10 000 has been made. Six different types of sedimentary deposits were defined and mapped. These are moraines, lacustrine sediments, fluvio-glacial deposits, talus slopes, debris fans and alluvial fans. Other mapped features also include shape of ravines, their depths, ridges and direction of sedimentary flow. Additionally areas of active, semi-active and inactive sedimentation were marked. Moraines forms a ridge in the bottom of the valleys and are composed of unconsolidated, poorly sorted, subangular grains ranging from clay size to a few cubic meters big blocks. Lacustrine sediments are represented by laminated well sorted sand and silt, while fluvio-glacial deposits are composed of washed out subrounded sands and gravels. Talus slope deposits are characterised by clast-supported poorly sorted very angular gravel. Debris flow fans are represented by extremely poorly sorted matrix-supported gravels with grain size ranging from clay to few cubic meters big blocks. Alluvial fans are composed by variety of sedimentary textures. Sediments at the fan apex are clast-supported poorly sorted very angular gravels with up to a few cubic meters big block. In the middle part of the fan the sieve deposits are common, while in the distal parts a few centimeters thick layers of sand and

  16. Generating geomorphological catalogues using neural networks: Seamounts in the Atlantic Ocean (United States)

    Valentine, Andrew; Kalnins, Lara; van Dinther, Chantal; Trampert, Jeannot


    We recently introduced the idea that neural networks may be used to construct catalogues of geomorphological features, by extrapolating from the characteristics of a set of hand-selected examples (Valentine et al., 2012). These learning algorithms are inspired by the complex pattern identification and recognition capabilities of the human brain and remove the need to develop an a priori model of the feature of interest. In order to demonstrate this approach, and to develop a clearer understanding of its possibilities and pitfalls, we concentrate on the problem of identifying seamounts - isolated topographic highs of volcanic origin - in the world's oceans. The distribution of seamounts in time and space can provide important constraints on the tectonic history and evolution of the Earth and has been studied using several conventional approaches (e.g. Kim & Wessel, 2011). However, these typically perform poorly in the Atlantic, where the slow spreading rate results in a rough 'background' seafloor that produces many false positives. The learning algorithm approach should improve this, as it attempts to encapsulate more complex information about the seamount and its surroundings. We present an overview of our work to date, with a focus on results from a systematic search for seamounts in the Atlantic. We compare the performance of our approach in detecting seamounts in bathymetric, free-air gravity anomaly and vertical gravity gradient (VGG) datasets to examine the particular strengths and weaknesses of each data type and to assess the potential benefits of assimilating information from two or three data types simultaneously. We compare the resulting seamount database with existing catalogues, examining the variations in measures such as total count, height distribution, and spatial and temporal distribution across the Atlantic, and comment on the potential implications for our understanding of the tectonic history of the region. Kim, S.-S. & Wessel, P., 2011. New

  17. Hazard connected to railway tunnel construction in karstic area: applied geomorphological and hydrogeological surveys

    Directory of Open Access Journals (Sweden)

    G. Casagrande


    Full Text Available In a mature karstic system, the realisation of galleries using the methodology of railway tunnel boring machine (TBM involves particular problems due to the high risk of interference with groundwater (often subject to remarkable level variations and with cavities and/or thick fill deposits. In order to define groundwater features it is necessary to investigate both hydrodynamic and karstification. To define and quantify the karst phenomenon in the epikarst of the Trieste Karst (Italy, an applied geomorphological approach has been experimented with surface and cavity surveys. The surface surveys have contributed to determining the potential karst versus the different outcropping lithologies and to define the structural setting of the rocky mass also through the realisation of geostructural stations and the survey of the main lines thanks to photo-interpretation. Moreover, all the dolines and the cavities present in the area interested by the gallery have been studied by analysing the probable extension of caves and/or of the secondary fill deposits and by evaluating the different genetic models. In an area 900m large and 27km long, which has been studied because of the underground karst, there are 41 dolines having diameters superior to 100m and 93 dolines whose diameters range between 100 and 50m; the dolines whose diameters are inferior to 50m are 282. The entrances of known and registered cavities in the cadastre records are 520. The hypogeal surveys have shown 5 typologies in which it has been possible to group all the cavities present in a hypothetical intersection with the excavation. The comparison between surface and hypogeal structural data and the direction of development of cavities has allowed for the definition of highly karstified discontinuity families, thus having a higher risk. The comparison of the collected data has enabled to identify the lithologies and areas having major risk and thus to quantify the probability of

  18. Potential glacial origin of the seabed geomorphology of the Porcupine Bank, west of Ireland (United States)

    Thébaudeau, Benjamin; McCarron, Stephen; Monteys, Xavier


    The Porcupine Bank lies west of Ireland between 51-54N and 11-15 W, located approximately between 150 km and 250 km from the Irish western coastline. The topography of the bank is gently sloping from the Porcupine Ridge contained within the 200m depth contour to the edge at the 500m depth contour. From then on, sharp escarpments occur to the north and west while the slope is gentler toward the Porcupine Seabight to the southeast. The Bank is linked to the Irish western shelf through a low ridge roughly 100km wide to the northeast. This region's geomorphology and shallow stratigraphy is still widely unexplored although it is located critically for our understanding of the last glaciation inception and termination of the British Irish Ice Sheet. The north-eastern Atlantic shelf region West of Ireland contains a relatively pristine record of glacial ice extension from Ireland and Scotland onto the shelf, probably during the last cold period (Late Midlandian glaciation in Ireland). Furthermore, national economic interest in the region is rising with long term investment being put forward for the Irish Marine Economy. Using multibeam and subbottom data collected more than a decade ago, the seabed surface of the region has been interpreted and mapped. Bedrock outcrop, sand ridges, erosional channels, iceberg scours and ridges of various forms have been recognised. These features show some clear influence of the proximal ice sheets as illustrated by the extensive coverage of iceberg scours. Similarly, the northern edge of the Porcupine Bank and the Porcupine Ridge in particular is characterised by large elongated ridges for which the origin is obscure. These appear roughly parallel to a W-E direction with some displaying a levelling effect on one of their sides. This paper will introduce the results of the mapping effort and argue for the interpretation of the above mentioned ridges as glacial in origin. Various scenarios of the consequences of that statement will then be


    Directory of Open Access Journals (Sweden)



    Full Text Available Some geomorphological and geoecological impacts of the 2010 extreme rainfalls in Hungary. The extreme rainfall events in the unusually wet year of 2010 brought about major changes in the floodplains of several streams in Hungary. On the small watercourses in low mountain or hill environments flash floods were generated. In the floodplains of medium-sized rivers, like the Kapos River in Southern Transdanubia, lasting inundations transformed the landscape. The system of wetlands preceeding the 19th-century river regulation and land drainage measures was restored by natural processes and within a very short time as excess water filled the entire broad valley sections in a shallow layer temporarily, for some weeks, and the former oxbows for several months. The nature conservation value of the river valley increased: reed and sedge beds and the brooding colonies of aquatic birds extended. There are, however, unfavorable impacts as well. Denser wetland vegetation significantly contributes to the organic filling of floodplain landforms. The spreading of invasive plants (allergetic ragweed, Ambrosia artemisiifolia, in the first place was promoted by the prolonged survival of extensive bare but moist silt surfaces in the floodplain. The long-term effects of this colonization on floodplain communities are unpredictable. A delayed and indirect impact of extreme rainfalls was the breach of a red sludge reservoir near the Ajka alumina plant in October, 2010 and the resulting environmental disaster. After the gradual accumulation of rainwater in the reservoir, the dyke breach happened, released 600-700 thousand m3 of basic (up to pH 13! sludge over the floodplain of the Torna Stream, a tributary of the Marcal and Rába rivers in an area of ca 40 km2. The emergency mitigation measures (spreading gypsum from power plants to neutralize the strong base over the layer of red sludge accumulation proved unfortunate as it prevented that the sludge should be washed

  20. Landslide hazard in Bukavu (DR Congo): a geomorphological assessment in a data-poor context (United States)

    Dewitte, Olivier; Mugaruka Bibentyo, Toussaint; Kulimushi Matabaro, Sylvain; Balegamire, Clarisse; Basimike, Joseph; Delvaux, Damien; Dille, Antoine; Ganza Bamulezi, Gloire; Jacobs, Liesbet; Michellier, Caroline; Monsieurs, Elise; Mugisho Birhenjira, Espoir; Nshokano, Jean-Robert; Nzolang, Charles; Kervyn, François


    Many cities in the Global South are known for facing an important increase in their population size. Many of them are then struggling with the sprawl of new settlements and very often urban planning and sustainable management policies are limited, if not non-existent. When those cities are set in landslide-prone environments, this situation is even more problematic. Despite these environmental constrains, landslide hazard assessments relevant for landscape planning remain rare. The objective of this research is to assess the landslide hazard in Bukavu, a city in DR Congo that is facing such a situation. We used a geomorphological approach (adapted from Cardinali et al., 2002) taking into account the data-poor context and the impact of anthropogenic activities. First, we built a multi-temporal historical inventory for a period of 60 years. A total of 151 landslides were mapped (largest landslide 1.5 km2). Their cumulative areas cover 29% of the urban territory and several types of processes are identified. Changes in the distribution and pattern of landslides allowed then to infer the possible evolution of the slopes, the most probable type of failures, and their expected frequency of occurrence and intensity. Despite this comprehensive inventory, hazard linked to the occurrence of new large deep-seated slides cannot be assessed due a scarcity of reliable data on the environmental factors controlling their occurrence. In addition, age estimation of the occurrence of some of the largest landslides refers to periods at the beginning of the Holocene where climatic and seismic conditions were probably different. Therefore, based on the inventory, we propose four hazard scenarios that coincide with today's environment. Hazard assessment was done for (1) reactivation of deep-seated slides, (2) occurrence of new small shallow slides, (3) rock falls, and (4) movements within existing landslides. Based on these assessments, we produced four hazard maps that indicate the

  1. Geomorphological facies reconstruction of Late Quaternary alluvia by the application of fluvial architecture concepts (United States)

    Houben, Peter


    .g., the sharpness of channel element geometry and the underlying ordering of bounding surfaces. Moreover, it is shown that the analytical process resembles an iterative looping process that is led by deduction. Many geomorphologists and multi-disciplinary floodplain researchers collect sedimentary data but still neglect utilizing the potential of architectural analysis. The study makes clear that sedimentological approaches used in 'big river' floodplains also apply to small valleys; in fact, the procedures for facies reconstruction need to be adjusted to each individual case study. Alluvial architecture analysis provides the tools to reveal interconnectedness (or disconnectedness) of channel, near-channel, and overbank fluvial landforms, which is essential for a geomorphological understanding of floodplain evolution.

  2. Micro-geomorphology Surveying and Analysis of Xiadian Fault Scarp, China (United States)

    Ding, R.


    analysis of offset strata of the trench, we conform that the middle segment of the fault scarp is made by 1679 earthquake; 4) The fault scarp strikes along with the Ju river at the northeast segment of the Xiadian fault which course the asymmetrical valley geomorphology.

  3. Geomorphology, internal structure and evolution of alluvial fans at Motozintla, Chiapas, Mexico (United States)

    Sánchez-Núñez, J. M.; Macías, J. L.; Saucedo, Ricardo; Zamorano, J. J.; Novelo, David; Mendoza, M. E.; Torres-Hernández, J. R.


    Alluvial fans and terraces develop in diverse regions responding to different tectonic and climatic conditions. The Motozintla basin is located in the State of Chiapas, southern Mexico and has an E-W orientation following the trace of the left-lateral Polochic Fault. The evolution of the Motozintla basin and the alluvial plain is related to several factors, such as fault movement, intense erosion by hydrometeorological events, and anthropogenic activity. This study presents the geomorphology of the alluvial plain that between the villages of Motozintla and Mazapa de Juárez exposes 31 alluvial fans, 5 hanging terraces and 13 ramps. Fourteen of these alluvial fans have been truncated by the Polochic fault, exposing maximum uplifts of ~ 12 m. The internal structure of truncated fans consists of single massive beds (monolithologic fans) or stacked beds (polygenetic fans). The fans' stratigraphy is made of debris flow deposits separated by paleosols and minor hyperconcentrated flows, fluviatile beds, and pyroclastic fall deposits. The reconstruction of the stratigraphy assisted by radiocarbon geochronology suggests that these fans have been active since late Pleistocene (25 ka) to the present. This record suggests that at least 10 events have been recorded at the fan interior during the past ~ 1840 years. One of these events at 355 ± 65 14C yrs. BP (cal yrs. AD 1438 to 1652) can be correlated across the fans and is likely associated with an extreme hydrometeorologic event. The presence of a 165 ± 60 14C yrs. BP (cal yrs. AD 1652-1949) debris flow deposit within the fans suggests that movement along the Polochic fault formed the fans' scarp afterwards. In fact, a historic earthquake along the fault occurred east of Motozintla on July 22, 1816 with a Mw of 7.5-7.75. Recent catastrophic floods have affected Motozintla in 1998 and 2005 induced by extreme hydrometeorological events and anthropogenic factors. Therefore, scenarios for Motozintla involved several types of

  4. Bridging arctic pathways: Integrating hydrology, geomorphology and remote sensing in the north (United States)

    Trochim, Erin D.

    This work presents improved approaches for integrating patterns and processes within hydrology, geomorphology, ecology and permafrost on Arctic landscapes. Emphasis was placed on addressing fundamental interdisciplinary questions using robust, repeatable methods. Water tracks were examined in the foothills of the Brooks Range to ascertain their role within the range of features that transport water in Arctic regions. Classes of water tracks were developed using multiple factor analysis based on their geomorphic, soil and vegetation characteristics. These classes were validated to verify that they were repeatable. Water tracks represented a broad spectrum of patterns and processes primarily driven by surficial geology. This research demonstrated a new approach to better understanding regional hydrological patterns. The locations of the water track classes were mapped using a combination method where intermediate processing of spectral classifications, texture and topography were fed into random forests to identify the water track classes. Overall, the water track classes were best visualized where they were the most discrete from the background landscape in terms of both shape and content. Issues with overlapping and imbalances between water track classes were the biggest challenges. Resolving the spatial locations of different water tracks represents a significant step forward for understanding periglacial landscape dynamics. Leaf area index (LAI) calculations using the gap-method were optimized using normalized difference vegetation index (NDVI) as input for both WorldView-2 and Landsat-7 imagery. The study design used groups to separate the effects of surficial drainage networks and the relative magnitude of change in NDVI over time. LAI values were higher for the WorldView-2 data and for each sensor and group combination the distribution of LAI values was unique. This study indicated that there are tradeoffs between increased spatial resolution and the ability

  5. Geomorphology of MODIS-Visible Dust Plumes in the Chihuahuan Desert - Preliminary Results (United States)

    Gill, T. E.; Mbuh, M. J.; Dominguez, M. A.; Lee, J. A.; Baddock, M. C.; Lee, C. E.; Whitehead, S. C.; Rivera Rivera, N. I.; Peinado, P.


    We identified 28 days since 2001 when blowing dust impacted El Paso, Texas and dust plumes were visible on NASA MODIS Terra/Aqua satellite images in the surrounding Chihuahuan Desert. Initiation points of >270 individual plumes were located on the MODIS images. Land use/land cover for each point was determined by field work, aerial photography, and/or soil/geological maps, and points were assigned to the geomorphic classes proposed by Bullard et al. (this session). Although dust plume identification is subjective (weak plumes, plumes obscured by clouds, and plumes occurring when the satellites are not overhead will be missed), these data provide preliminary information on the relationship between geomorphology and the initiation of major dust storms in the Chihuahuan Desert. Ephemeral lakes and alluvial low-relief non-incised lands are roughly equal producers of satellite-visible dust plumes in the Chihuahuan Desert. Anthropogenic modification of alluvial floodplains for cropping (primarily in the Casas Grandes and Del Carmen river basins) impacts dust generation, since about 2/3 of alluvial low-relief sites show evidence of agriculture. These agricultural fields are generally fallow during the November- April windy season. Not including agricultural lands, playas represent ~2x the number of sources as low-relief alluvial deposits. Aeolian sand deposits (predominantly coppice dunes and sand sheets overlaying alluvial or lacustrine sediments) account for about 1/7 of the points. These sands may act as erosional agents, providing saltating particles for sandblasting and bombardment of other sediments exposed nearby. Edges of ephemeral lakes are proportionally important sources (~10% of the points), likely due to the convergence of saltating sand, fine lacustrine sediments, and low roughness lengths of playa surfaces. Alluvial fans and alluvial uplands are minor dust sources compared to their overall prevalence in the region. Gobi/gibber/stony deposits are known dust

  6. The seabed geomorphology and geological structure of the Firth of Lorn, western Scotland, UK (United States)

    Howe, John; Arosio, Riccardo; Dove, Dayton; Anderton, Roger; Bradwell, Tom


    geomorphological mapping shows that our understanding of the offshore outcrop geology can be greatly improved by the collection of these new high-resolution bathymetric datasets.

  7. Fault-controlled geomorphology and paleoseismology of Fethiye fault and gulf (United States)

    Chatzipetros, Alexandros; Pavlides, Spyros; Yaǧmurlu, Fuzuli; Özgür, Nevzat; Kamaci, Züheyr; Şentürk, Murat


    Fethiye gulf is located at the south-westernmost part of the large left-lateral Fethiye-Burdur fault zone. It is modified and controlled by sets of NE - SW trending normal and oblique left-lateral faults. The gulf forms coastlines that are often aligned nearly perpendicular to one another. Coastlines are mainly NE - SW trending and they are inundated by small bays, mainly in NNW-SSE direction. Those directions are comparable to the main mainland fault lines, as measured on outcrops in the area. The brittle features of the area overprint the pre-existing tectonic fabric of low-angle thrusts and pure strike-slip faults. Recent activity of the faults seems to be possible, since there is indication for hangingwall submergence at the "Cleopatra's bath" site, where an early-Byzantine building complex has been submerged by at least 2 m. The mainland active fault zone is located S-SE of Fethiye town and it forms an N-NW dipping fault scarp that is characterized by multiple en échelon segments. The quantitative tectonic geomorphology of this fault has been studied by using morphotectonic indices (scarp sinuosity, valley width/depth ratio, etc.), which show that the fault has a rather low level of activity. Nevertheless, the fault zone near Fethiye presents other morphotectonic features, such as riverbed catchment, slight left-lateral bend of streams at the foot of the scarp, etc. The fault zone seems to fan out towards the west and the deformation is less evident. Although the fault segments near Fethiye are classified as low-activity ones, they are associated with the large 1957 earthquake (Ms 7.1). This earthquake produced extensive damage and casualties. It was physically manifested by surface ruptures, rockfalls, etc. A palaeoseismological survey has been carried out in the area. Trenches in two different segments show that the 1957 surface rupture is traceable along the fault, while at least two previous events seem to have affected the area and produced surface

  8. Combining geomorphological mapping and near surface geophysics (GPR and ERT) to study piping systems (United States)

    Bernatek-Jakiel, Anita; Kondracka, Marta


    This paper aims to provide a more comprehensive characterization of piping systems in mountainous areas under a temperate climate using geomorphological mapping and geophysical methods (electrical resistivity tomography - ERT and ground penetrating radar - GPR). The significance of piping in gully formation and hillslope hydrology has been discussed for many years, and most of the studies are based on surface investigations. However, it seems that most surface investigations underestimate this subsurface process. Therefore, our purpose was to estimate the scale of piping activity based on both surface and subsurface investigations. We used geophysical methods to detect the boundary of lateral water movement fostering pipe development and recognize the internal structure of the underlying materials. The survey was carried out in the Bereźnica Wyżna catchment, in the Bieszczady Mountains. (Eastern Carpathians, Poland), where pipes develop in Cambisols at a mean depth of about 0.7-0.8 m. The geophysical techniques that were used are shown to be successful in identifying pipes. GPR data suggest that the density of piping systems is much larger than that detectible from surface observations alone. Pipe length can be > 6.5-9.2% (maximum = 49%) higher than what surface mapping suggests. Thus, the significance of piping in hillslope hydrology and gully formation can be greater than previously assumed. These results also draw attention to the scale of piping activity in the Carpathians, where this process has been neglected for many years. The ERT profiles reveal areas affected by piping as places of higher resistivity values, which are an effect of a higher content of air-filled pores (due to higher soil porosity, intense biological activity, and well-developed soil structure). In addition, the ERT profiles show that the pipes in the study area develop at the soil-bedrock interface, probably above the layers of shales or mudstones which create a water restrictive layer

  9. How geomorphology and groundwater level affect the spatio-temporal variability of riverine cold water patches? (United States)

    Wawrzyniak, Vincent; Piégay, Hervé; Allemand, Pascal; Vaudor, Lise; Goma, Régis; Grandjean, Philippe


    Temperature is a key factor for river ecosystems. In summer, patches of cold water are formed in the river by groundwater seepage. These patches have strong ecological significance and extend to the surface water in a well-mixed riverine system. These patches can serve as thermal refuges for some fish species during summer. In this study, the temporal variability and spatial distribution of cold water patches were explored along a 50 km river reach (the lower Ain River, France) using thermal infrared airborne remote sensing. This study examines a new range of processes acting on cold water patches at different scales that have not previously been touched upon in the literature. Three airborne campaigns were conducted during the summers of 2010, 2011 and 2014. Based on these images, a large number of cold water patches were identified using an automated method. Four types of patches were observed: tributary plumes, cold side channels (former channels or point-bar backwater channels), side seeps (located directly in the river channel) and gravel bar seeps (occurring at the downstream end of gravel bars). Logistic regression was used to analyse the longitudinal distribution of cold water patches according to geomorphologic indicators reflecting current or past fluvial process. Side seeps were found to be related to the local geology. Cold side channels were correlated to contemporary and past lateral river mobility. Gravel bar seeps were related to the current development of bars and are more prevalent in wandering reaches than in single-bed incised and paved reaches. The logistic model was subsequently used to evaluate gravel bar seep variability in the past. The model suggests larger numbers of seeps in the mid-20th century when bar surface area was higher. Interannual variability in the occurrence and spatial extent of side seeps and gravel bar seeps appear to be related to groundwater level fluctuations. Cold side channels exhibited greater interannual stability

  10. Physicochemical Properties, Micromorphology and Clay Mineralogy of Soils Affected by Geological Formations, Geomorphology and Climate

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    A. Bayat


    Full Text Available Introduction: Soil genesis and development in arid and semi-arid areas are strongly affected by geological formations and geomorphic surfaces. Various morphological, physical, and geochemical soil properties at different geomorphic positions are usually attributed to different soil forming factors including parent material and climate. Due to variations in climate, geological formations (Quaternary, Neogene and Cretaceous and geomorphology, the aim of the present research was the study of genesis, development, clay mineralogy, and micromorphology of soils affected by climate, geology and geomorphology in Bardsir area, Kerman Province. Materials and Methods: The study area, 25000 ha, starts from Bardsir and extends to Khanesorkh elevations close to Sirjan city. The climate of the area is warm and semi-arid with mean annual temperature and precipitation of 14.9 °C and 199 mm, respectively. Soil moisture and temperature regimes of the area are aridic and mesic due to 1:2500000 map, provided by Soil and Water Research Institute. Moving to west and southwest, soil moisture regime of the area changes to xeric with increasing elevation. Using topography and geology maps (1:100000 together with Google Earth images, geomorphic surfaces and geologic formations of the area were investigated. Mantled pediment (pedons 1, 3, 7, and 8, rock pediment (pedon 2, semi-stable alluvial plain (pedon 6, unstable alluvial plain (pedon 5, piedmont plain (pedons 9 and 11, intermediate surface of alluvial plain and pediment (pedon 4, and old river terrace (pedon 10 are among geomorphic surfaces investigated in the area. Mantled pediment is composed of young Quaternary sediments and Cretaceous marls. Rock pediments are mainly formed by Cretaceous marls. Quaternary formations are dominant in alluvial plains. Alluvial terraces and intermediate surface of alluvial plain and pediment are dominated by Neogene conglomerates. Siltstone, sandstone, and Neogene marls together with

  11. Geomorphological & Geoarchaeological Indicators of the Holocene Sea-Level Changes on Ras El Hekma Area, NW Coast of Egypt (United States)

    Torab, Magdy


    Ras El Hekma area is a part of the NW coast of Egypt. It is located on the Egyptian Mediterranean Coast, approximately 220 km West of Alexandria City. It is shaped as a triangle with its headland extending into the Mediterranean sea for about 15 km, and is occupied by sedimentary rocks belonging to the Tertiary and Quaternary Eras. Its western coastline consists of Pleistocene Oolitic limestone ridges with separated steep scarps, while the eastern coastline consists of sandy beaches, coastal spits, coastal bars, tombolos and bays. The objective of this paper is to define some geomorphological and geoarchaelological indicators of The Holocene sea-level changes in the study area, especially the geomorphic landforms such as: marine notches, cliffs, sea caves and benches. This is to add to some archaeological remains that have been discovered by the paper's author under the current sea level. These remains include: submerged ruins of Greek and Roman harbors, wells and fish tanks near the coastline (Leuke Akte, Hermaea, Phoinikous and Zygris), in addition to an ancient Roman harbor used during the World War II in Tell El Zaytun area (Site #6). Evaluations of the discovered archaeological remains help our understanding of the evolution of the sea level during the Holocene. This study is based on observation of the relative sea-level curves drawn of the Holocene, detailed geomorphological and Geoarchaelogical surveying, sampling, dating and mapping as well as satellite image interpretation and GIS techniques.

  12. Volcanic evolution of central Basse-Terre Island revisited on the basis of new geochronology and geomorphology data (United States)

    Ricci, J.; Quidelleur, X.; Lahitte, P.


    Twenty-six new and seven previous K-Ar ages obtained on groundmass separates for samples from the Axial Chain massif (Guadeloupe, F.W.I.), associated with geomorphological investigations, allow us to propose a new model of the volcanic evolution of the central part of Basse-Terre Island. The Axial Chain is composed of four edifices, Moustique, Matéliane, Capesterre, and Icaque mounts, showing coeval activity from 681 ± 12 to 509 ± 10 ka, which contradicts a previous hypothesis that flank collapse affected them successively. Our geomorphological reconstruction shows that the Axial Chain can be considered as a single large volcano, named the Southern Axial Chain volcano (SCA), rather than a succession of several smaller volcanoes. It raises questions regarding the formation of a large depression within the SCA volcano, prior to the construction of the Sans-Toucher volcano between 451 ± 13 and 412 ± 8 ka. Given presently available evidence, a slump affecting the western part of the SCA volcano is the most probable scenario to reconcile the complete age dataset and the present-day morphology of central Basse-Terre. Finally, our study shows that the SCA volcano had a post-activity volume of 90 km3, implying a construction rate of 0.5 km3/kyr. This value strongly constrains interpretations of magma generation processes throughout the Lesser Antilles arc.

  13. Assessment and Management of the Geomorphological Heritage of Monte Pindo (NW Spain: A Landscape as a Symbol of Identity

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    Manuela Costa-Casais


    Full Text Available This study focuses on the granite mountain known as Monte Pindo (627 m above sea level in the Autonomous Community of Galicia (NW Spain. This territory is included in the area classified as “Costa da Morte” in the “Politica de Ordenación Litoral” (POL (Coastal Planning Policy for the region of Galicia. This coastal unit, located between “Rías Baixas” and “Cape Fisterra” has great potential for demonstrating geological processes and its geomorphological heritage is characterized by a high degree of geodiversity of granite landforms. The main objective of our work is to assess the geomorphological heritage of the site, thus revealing its wide geodiversity. We shall analyze and highlight: its scientific value, developing an inventory of granite landforms; its educational valuel and its geotouristic potential. It must be ensured that the Administration understands that natural diversity is composed of both geodiversity and biodiversity. Only then will the sustainable management of Monte Pindo become possible by integrating natural and cultural heritage values. The goal is to ensure that Monte Pindo and its immediate surroundings become a geopark with the aim of promoting local development projects based on the conservation and valorization of its geological heritage.

  14. Integrated Hydro-geomorphological Monitoring System of the Upper Bussento river basin (Cilento and Vallo Diano Geopark, S-Italy) (United States)

    Guida, D.; Cuomo, A.; Longobardi, A.; Villani, P.; Guida, M.; Guadagnuolo, D.; Cestari, A.; Siervo, V.; Benevento, G.; Sorvino, S.; Doto, R.; Verrone, M.; De Vita, A.; Aloia, A.; Positano, P.


    The Mediterranean river ecosystem functionings are supported by river-aquifer interactions. The assessment of their ecological services requires interdisciplinary scientific approaches, integrate monitoring systems and inter-institutional planning and management. This poster illustrates the Hydro-geomorphological Monitoring System build-up in the Upper Bussento river basin by the University of Salerno, in agreement with the local Basin Autorities and in extension to the other river basins located in the Cilento and Vallo Diano National Park (southern Italy), recently accepted in the European Geopark Network. The Monitoring System is based on a hierarchical Hydro-geomorphological Model (HGM), improved in a multiscale, nested and object-oriented Hydro-geomorphological Informative System (HGIS, Figure 1). Hydro-objects are topologically linked and functionally bounded by Hydro-elements at various levels of homogeneity (Table 1). Spatial Hydro-geomorpho-system, HG-complex and HG-unit support respectively areal Hydro-objects, as basin, sector and catchment and linear Hydro-objects, as river, segment, reach and section. Runoff initiation points, springs, disappearing points, junctions, gaining and water losing points complete the Hydro-systems. An automatic procedure use the Pfafstetter coding to hierarchically divide a terrain into arbitrarily small hydro-geomorphological units (basin, interfluve, headwater and no-contribution areas, each with a unique label with hierarchical topological properties. To obtain a hierarchy of hydro-geomorphological units, the method is then applied recursively on each basin and interbasin, and labels of the subdivided regions are appended to the existing label of the original region. The monitoring stations are ranked consequently in main, secondary, temporary and random and located progressively at the points or sections representative for the hydro-geomorphological responses by validation control and modeling calibration. The datasets

  15. The impact of the Quaternary glaciations on the Durmitor mountains (Montenegro) as understood from detailed geomorphological mapping (United States)

    Frankl, Amaury; Annys, Klaas; Spalević, Velibor; Čurović, Milic; Borota, Dragan; Nyssen, Jan


    In the Balkans, few studies exist that highlight the impact of the Quaternary glaciations on the landscape. However, the impact of the Quaternary glaciations was important and the glacial imprint remains well preserved in the limestone massifs where karst hydrology prevails. This study presents a detailed geomorphological map at scale 1:10,000 that was prepared of the northeastern Durmitor mountains (2523 m a.s.l.) and the plateau Jezerska Površ (47 km², Dinaric Alps, Montenegro). Mapping occurred from an intensive fieldwork campaign and remote sensing analysis, and was finalized in a GIS environment. The basic components of the legend are (i) processes/genesis, (ii) materials, (iii) morphometry/morphography, (iv) hydrography, (v) vegetation and (vi) anthropogenic features, that are organized as a box-of-bricks type of legend (AGRG-system). The geomorphological setting of the area consists of Mesozoic limestones which were eroded physically by Quaternary glacial and periglacial activity and chemically during interglacials. Glacial deposits of three Middle to Late Pleistocene glacial phases exist on the plateau, only scarcely dissected by meltwater channels. In the mountains, Holocene glacier retreat left behind a series of well-preserved recessional moraines and a static glacier remains in the cirque head. The presented map serves as a valuable tool for Quaternary research in the Durmitor Mountains, and serves as an example on the interaction between glacial and karst processes. Keywords: Debeli Namet glacier, Dinaric Alps, Geographic Information System (GIS), Glacial landforms, Karst.

  16. Hanging canyons of Haida Gwaii, British Columbia, Canada: Fault-control on submarine canyon geomorphology along active continental margins (United States)

    Harris, Peter T.; Barrie, J. Vaughn; Conway, Kim W.; Greene, H. Gary


    Faulting commonly influences the geomorphology of submarine canyons that occur on active continental margins. Here, we examine the geomorphology of canyons located on the continental margin off Haida Gwaii, British Columbia, that are truncated on the mid-slope (1200-1400 m water depth) by the Queen Charlotte Fault Zone (QCFZ). The QCFZ is an oblique strike-slip fault zone that has rates of lateral motion of around 50-60 mm/yr and a small convergent component equal to about 3 mm/yr. Slow subduction along the Cascadia Subduction Zone has accreted a prism of marine sediment against the lower slope (1500-3500 m water depth), forming the Queen Charlotte Terrace, which blocks the mouths of submarine canyons formed on the upper slope (200-1400 m water depth). Consequently, canyons along this margin are short (4-8 km in length), closely spaced (around 800 m), and terminate uniformly along the 1400 m isobath, coinciding with the primary fault trend of the QCFZ. Vertical displacement along the fault has resulted in hanging canyons occurring locally. The Haida Gwaii canyons are compared and contrasted with the Sur Canyon system, located to the south of Monterey Bay, California, on a transform margin, which is not blocked by any accretionary prism, and where canyons thus extend to 4000 m depth, across the full breadth of the slope.

  17. Using Fluvial Geomorphology as a Physical Template in Process-Based and Recovery Enhancement Approaches to River Management (United States)

    Fryirs, K.


    In an `era of river repair' fluvial geomorphology has emerged as a key science in river management practice. Geomorphologists are ideally placed to use their science in an applied manner to provide guidance on the impact of floods and droughts, landuse and climate change, and water use on river forms, processes and evolution. Increasingly, fluvial geomorphologists are also asked to make forecasts about how systems might adjust in the future, and to work with managers to implement strategies on-the-ground. Using case study material from Eastern Australia (Bega, Hunter, Wollombi and Lockyer catchments) I will focus on how process-based understanding of rivers has developed and evolved to provide a coherent physical template for effective and proactive, river management practice. I will focus on four key principles and demonstrate how geomorphology has been, and should continue to be, used in process-based, recovery enhancement approaches to river management. How understanding the difference between river behaviour and river change is used to determine how a river is `expected' to function, and how to identify anomalous processes requiring a treatment response. How understanding evolutionary trajectory is used to make future forecasts on river condition and recovery potential, and how working with processes can enhance river recovery. How geomorphic information can be used as a physical template atop which to analyse a range of biotic processes and habitat outcomes. How geomorphic information is used to effectively prioritise and plan river conservation and rehabilitation activities as part of catchment and region-scale action plans.

  18. Assessment and protection of geomorphological heritage in the Gruyère - Pays-d'Enhaut Regional Nature Park (Switzerland) (United States)

    Bussard, Jonathan; Reynard, Emmanuel


    This research deals with two main issues: (1) the protection of the abiotic nature and (2) the promotion of geotourism in a protected area, the Gruyère - Pays-d'Enhaut Regional Nature Park (Switzerland). First, an identification and assessment of the geomorphological heritage is conducted, with special attention given to the degree of protection of the sites. The assessment is carried out using the method developed by Reynard et al. (2007), partly modified (addition of new criteria concerning the present use and management of the sites). Secondly, we try to understand how the stakeholders active in the tourism sector take into account the Earth heritage (especially geomorphosites). The final goal is to give some perspectives for a suitable protection and a better promotion of the geomorphosites. The Gruyère - Pays-d'Enhaut Regional Nature Park is one of the new nature parks developed during the last decade in Switzerland. Created in 2012, it covers a surface of 503 square kilometers on the territory of 13 municipalities. It is managed by an association constituted by the 13 municipalities and by private individuals, companies and societies. The three main objectives of the park are (1) the preservation and qualitative development of nature and landscape; (2) the promotion of sustainable economic activities; and (3) raising public awareness and environmental education. The park is situated in the Swiss Prealps (altitudes ranging from 375 to 2548 m ASL) and is characterised by extensive structural landforms and numerous relicts of Quaternary glaciations. 33 sites were inventoried. Most of them (27 sites) are related to three main geomorphological processes: karst formations, relicts of glacial/periglacial processes and fluvial landforms. The other sites are related to gravity processes, to organic processes and to the structural context. The inventory shows that the study area has a high diversity of landforms and presents a large set of geomorphosites with an

  19. Reconstruction of cryospheric changes in the Maipo and Juncal river basins, central Andes of Chile: an integrative geomorphological approach (United States)

    Nussbaumer, Samuel U.; García, Juan L.; Gómez, Gabriel; Vega, Rodrigo M.; Gärtner-Roer, Isabelle; Salzmann, Nadine


    Water in the central Andes (32-38° S), a semi-arid mountainous area with elevations over 6000 m asl., is of great importance and a critical resource especially in the dry summer months. Ice bodies, such as glaciers and rock glaciers (permafrost) in the high mountains, provide a substantial part of the fresh-water resources but also for intensive economical use for the lowlands including Santiago metropolitan region, Chile. However the evolution of these ice bodies since the last deglaciation (i.e., Holocene, last ˜12,000 years), and in particular during historical times, and their feedback with climate is fairly unknown. In view of projected climate change, this is striking because it is also unknown whether these natural resources could be used as sustainable fresh-water source in the future. Within the presented project, we develop and apply an integrative geomorphologic approach to study glaciers and their long-term evolution in the central Andes of Chile. Apart from glaciers (with variable debris-coverage), rock glaciers have evolved over time as striking geomorphological landforms in this area. We combine geomorphologic mapping using remote-sensing and in-situ data with an innovative surface exposure dating technique to determine the ages of distinct moraine ridges at three study sites in watersheds of the Santiago region: Juncal Norte, Loma Larga and Nieves Negras glaciers. First results of the project are presented, including a detailed geomorphological mapping and first analysis of the landform dynamics. At all three sites, we distinguished at least three moraine systems of a Holocene putative age. These prominent moraine belts show that glaciers were at least 5 km longer than at present. Deglaciation from these ice marginal positions was gradual and complex in response to the detrital cover on the glaciers. Differences in ice thickness of the main glaciers in the respective valleys amount to about 100 m. Due to the partial, extensive debris coverage, the


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    Full Text Available The Impact of Mining Activities on the West of Petroşani Depression and Identification of Affected Geomorphological Resources. Case Study: Aninoasa- Vulcan-Lupeni Sector. The west region of Petroşani Depression, like the whole depression, suffered some changes in the geomorphologic environment as a result of coal mining activities. Following displacement processes of mass materials and relocation of it, changes in shape are brought to the original territory that contrast with the natural landscape. The human impact on the West of Petroşani Depression and hence to the analyzed sector is especially highlighted as it materializes into waste dumps and coal pits.

  1. Geomorphological method in the elaboration of hazard maps for flash-floods in the municipality of Jucuarán (El Salvador

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    C. Fernández-Lavado


    Full Text Available This work deals with the elaboration of flood hazard maps. These maps reflect the areas prone to floods based on the effects of Hurricane Mitch in the Municipality of Jucuarán of El Salvador. Stream channels located in the coastal range in the SE of El Salvador flow into the Pacific Ocean and generate alluvial fans. Communities often inhabit these fans can be affected by floods. The geomorphology of these stream basins is associated with small areas, steep slopes, well developed regolite and extensive deforestation. These features play a key role in the generation of flash-floods. This zone lacks comprehensive rainfall data and gauging stations. The most detailed topographic maps are on a scale of 1:25 000. Given that the scale was not sufficiently detailed, we used aerial photographs enlarged to the scale of 1:8000. The effects of Hurricane Mitch mapped on these photographs were regarded as the reference event. Flood maps have a dual purpose (1 community emergency plans, (2 regional land use planning carried out by local authorities. The geomorphological method is based on mapping the geomorphological evidence (alluvial fans, preferential stream channels, erosion and sedimentation, man-made terraces. Following the interpretation of the photographs this information was validated on the field and complemented by eyewitness reports such as the height of water and flow typology. In addition, community workshops were organized to obtain information about the evolution and the impact of the phenomena. The superimposition of this information enables us to obtain a comprehensive geomorphological map. Another aim of the study was the calculation of the peak discharge using the Manning and the paleohydraulic methods and estimates based on geomorphologic criterion. The results were compared with those obtained using the rational method. Significant differences in the order of magnitude of the calculated discharges were noted. The rational method

  2. Geomorphological impact on agroforestry systems in the interior highlands of Nicaragua, Central America (United States)

    Mentler, Axel; Wriessnig, Karin; Ottner, Franz; Schomakers, Jasmin; Benavides González, Álvaro; Cisne Contreras, José Dolores; Querol Lipcovich, Daniel


    slope is influenced by accumulation of pyroclastic material. Theses soils can be characterized through a closer C:N ratio, higher pH (5.7-6.2) values, and plant available phosphorus reach values of 23 mg/kg. The mineralogical analyses illustrated less weathered volcanic material here and in the investigated samples zeolithe, smectite and a higher amount of plagioclase could be found. Cristobalite und pyroxene could be detected in all samples and indicate the influence of volcanic activity. Smectite und zeolithe are reason for the higher CEC values of these soils. Erosion and intensive tropical weathering processes including solutional weathering of limestones decline production potential at higher altitudes. Agroforestry systems are the most adapted systems for sustainable plant production systems in this area. Phosphorus release of soil is strongly influenced by the geomorphology of this landscape. Limiting parameters of this production system is the amount and the distribution of precipitation. The impact of global change to this specific area of Nicaragua will lead to extreme values of local precipitation events and an increase in temperature. If these events continue important production areas for optimum coffee production in agroforestry systems in Central America will be lost. Acknowledgement: This project was financed through the Austrian APPEAR program (OEAD).

  3. Integrating understanding of hydrology, geomorphology and ecology to better predict periphyton abundance in New Zealand rivers (United States)

    Hoyle, Jo; Kilroy, Cathy; Hicks, Murray


    concentration and periphyton biomass data (laboratory measures of chlorophyll a and percentage cover of thin films, filaments and mats/sludge). For each reach we set up a 1-d hydraulic model and established relationships between discharge and a number of hydraulic and geomorphic variables, including the discharge required to partially and fully mobilise the bed sediment. These were then related to the flow and periphyton monitoring records to examine the strength of relationships. Relating periphyton biomass data to antecedent flow data allowed us to identify threshold flows for periphyton removal. These flows were found to be 0.9 - 9.8 times the median flow, depending on the site, with the average across sites being 3.3 times the median flow. Results also showed that general mobility of the gravelly/cobbly bed material was not required to remove periphyton but that mobility of over-passing sand (through its abrasive action) is a key control on periphyton abundance. Relationships between soluble inorganic nitrogen and periphyton abundance were found to be strong at sites where sand is mobilized infrequently but weak at sites where sand is mobilized often. Overall results indicate that integrating understanding of geomorphology, hydrology and ecology can improve prediction of periphyton abundance in New Zealand rivers.

  4. Application of terrestrial laser scanning for coastal geomorphologic research questions in western Greece (United States)

    Hoffmeister, Dirk; Curdt, Constanze; Tilly, Nora; Ntageretzis, Konstantin; Aasen, Helge; Vött, Andreas; Bareth, Georg


    surface roughness and along recent beaches, post-processing of point clouds turned out to be more difficult, due to noise effects by water and shadowing effects. A point to point comparison was used in addition to check the results. (ii) Furthermore, it is possible to obtain highly accurate volumetric data of dislocated boulders by 3D reconstruction. Further parameters, such as inclination, elevation above sea level or the distance of the boulder to the sea can be extracted from the 3D model of the study site. Accurate maps of the geomorphological settings are established. All parameters were incorporated into selected wave transport equations, which regard the variable "mass" as a direct input parameter for the calculation of wave heights and velocities needed for boulder dislocation. Our results were compared to data based on manual measurement of boulder axes and roughly estimated rock density values, which show a combined, general overestimation of ~40%.

  5. Tracing peatland geomorphology: sediment and contaminant movements in eroding and restored systems (United States)

    Shuttleworth, Emma; Evans, Martin; Hutchinson, Simon; Rothwell, James


    Peatlands are an important store of soil carbon, play a vital role in global carbon cycling, and can also act as sinks of atmospherically deposited heavy metals. However, large areas of blanket peat are significantly degraded and actively eroding as a direct result of anthropogenic pressures, which negatively impacts carbon and pollutant storage. The restoration of eroding UK peatlands is a major conservation concern, and over the last decade measures have been taken to control erosion and restore large areas of degraded peat. In severely eroded peatlands, topography is highly variable, and an appreciation of geomorphological form and process is key in understanding the controls on peatland function, and in mitigating the negative impacts of peatland erosion. The blanket peats of the Peak District, Southern Pennines, UK embody many problems and pressures faced by peatlands globally, and are amongst the most heavily eroded and contaminated in the world. The near-surface layer of the peat is contaminated by high concentrations of anthropogenically derived, atmospherically deposited heavy metals which are released into the fluvial system as a consequence of widespread erosion. Whilst not desirable, this legacy of lead pollution and its release offer a unique opportunity to trace peatland sediment movements and thus investigate the controls on sediment and contaminant mobility. A suite of established field, analytical and modelling techniques have been modified and adapted for use in peatland environments and these have been successfully employed in combination to address issues of sediment and contaminant release at a range of scales, including: (i) the development of field portable XRF to assess in situ lead concentrations in wet organic sediments; (ii) adaptation of time integrated mass flux samplers to explore spatial and temporal sediment dynamics in peatland streams; and (iii) the application of sediment source fingerprinting and numerical mixing models to

  6. Geomorphological control of water tables in a blanket peat landscape: implications for carbon cycling (United States)

    Allott, Tim; Evans, Martin; Lindsay, John; Agnew, Clive; Freer, Jim


    than intact sites. This site-scale effect is hypothesised to result from reduced hydrological contributing areas (drainage areas) at eroded sites, with hillslope drainage diverted into gully channels. Distinct patterns of temporal water table behaviour are apparent between intact and heavily eroded locations. At intact locations water tables are predominantly close to the ground surface, except during periods of dry weather when a pattern of gradual water table drawdown occurs. Water tables rise rapidly following rainfall. This behaviour is characteristic of intact blanket peats in other regions. Water table behaviour at heavily eroded locations is very different, characterised by predominantly low water table conditions with ‘wet-up' responses to rainfall, i.e. very rapid rises in water table followed immediately by rapid drain-down after the cessation of rainfall. These spatio-temporal patterns in water tables conditions demonstrate the very different hydrological behaviours of eroded and intact peats. In this eroded peatland landscape there is strong geomorphological control on water table conditions. Implications for both the hydrological functioning of the peatland and the carbon cycle are discussed.

  7. Geology and geomorphology of Bear Lake Valley and upper Bear River, Utah and Idaho (United States)

    Reheis, M.C.; Laabs, B.J.C.; Kaufman, D.S.


    levels have decreased from as high as 1830 m to 1806 m above sea level since the early Pleistocene due to episodic downcutting by the Bear River. The oldest exposed lacustrine sediments in Bear Lake Valley are probably of Pliocene age. Several high-lake phases during the early and middle Pleistocene were separated by episodes of fluvial incision. Threshold incision was not constant, however, because lake highstands of as much as 8 m above bedrock threshold level resulted from aggradation and possibly landsliding at least twice during the late-middle and late Pleistocene. Abandoned stream channels within the low-lying, fault-bounded region between Bear Lake and the modern Bear River show that Bear River progressively shifted northward during the Holocene. Several factors including faulting, location of the fluvial fan, and channel migration across the fluvial fan probably interacted to produce these changes in channel position. Late Quaternary slip rates on the east Bear Lake fault zone are estimated by using the water-level history of Bear Lake, assuming little or no displacement on dated deposits on the west side of the valley. Uplifted lacustrine deposits representing Pliocene to middle Pleistocene highstands of Bear Lake on the footwall block of the east Bear Lake fault zone provide dramatic evidence of long-term slip. Slip rates during the late Pleistocene increased from north to south along the east Bear Lake fault zone, consistent with the tectonic geomorphology. In addition, slip rates on the southern section of the fault zone have apparently decreased over the past 50 k.y. Copyright ?? 2009 The Geological Society of America.

  8. Predicting debris flow occurrence in Eastern Italian Alps based on hydrological and geomorphological modelling (United States)

    Nikolopoulos, Efthymios I.; Borga, Marco; Destro, Elisa; Marchi, Lorenzo


    Most of the work so far on the prediction of debris flow occurrence is focused on the identification of critical rainfall conditions. However, findings in the literature have shown that critical rainfall thresholds cannot always accurately identify debris flow occurrence, leading to false detections (positive or negative). One of the main reasons for this limitation is attributed to the fact that critical rainfall thresholds do not account for the characteristics of underlying land surface (e.g. geomorphology, moisture conditions, sediment availability, etc), which are strongly related to debris flow triggering. In addition, in areas where debris flows occur predominantly as a result of channel bed failure (as in many Alpine basins), the triggering factor is runoff, which suggests that identification of critical runoff conditions for debris flow prediction is more pertinent than critical rainfall. The primary objective of this study is to investigate the potential of a triggering index (TI), which combines variables related to runoff generation and channel morphology, for predicting debris flows occurrence. TI is based on a threshold criterion developed on past works (Tognacca et al., 2000; Berti and Simoni, 2005; Gregoretti and Dalla Fontana, 2008) and combines information on unit width peak flow, local channel slope and mean grain size. Estimation of peak discharge is based on the application of a distributed hydrologic model, while local channel slope is derived from a high-resolution (5m) DEM. Scaling functions of peak flows and channel width with drainage area are adopted since it is not possible to measure channel width or simulate peak flow at all channel nodes. TI values are mapped over the channel network thus allowing spatially distributed prediction but instead of identifying debris flow occurrence on single points, we identify their occurrence with reference to the tributary catchment involved. Evaluation of TI is carried out for five different basins

  9. The quinoa boom of the southern Bolivian Altiplano - linking geomorphology, erosion and spatial production patterns (United States)

    Sander, Lasse; Jacobsen, Sven-Erik


    Quinoa (Chenopodium quinoa Willd.) is a native Andean crop that gained worldwide popularity over the last few decades due to its outstanding nutritional properties. The plant is characterized by an exceptional adaptation and is able to produce decent yields despite harsh environmental conditions like drought, frost, or soil salinity. Quinoa is thus an exceptional income opportunity in the arid southern Bolivian Altiplano, an area endemically struck by rural poverty and malnutrition. In the early 1970s, the Bolivian government introduced the first tractors to southern Bolivia's Salar region with the intention to push agricultural development - with obvious success. The cultivation of quinoa is today the most important land use, with a continued increase in production volume and areal extent. We here trace back land-use changes from 1972 to 2013 in one of the most important areas of quinoa production. Using Landsat images, SRTM elevations and field survey data, we investigate the relationship of field areas to erosion patterns and large-scale geomorphology. The soils of the southern Bolivian Altiplano are highly susceptible to particle entrainment due to a loose and sandy substrate, strong winds, and rapid drainage during precipitation and snow melt events. It appears that many of the first quinoa fields were established on flood plain deposits, where good yields could be anticipated despite the apparent risk of erosion. The subsequent expansion of production areas was paralleled by an increase in field density. Locally, this implied a reduction of fallowing length and the incorporation of marginal lands. The almost complete removal of natural (i.e. protecting) vegetation over large and continuous areas, results in increased wind erosion and partial crop failure. While production extended by approx. 1,6 % per year between 1985 and 2003, an average annual increase of 8,4 % could be observed for the last decade, when many new fields were established at lower elevations

  10. Exploring the Geomorphology of the Amazon's Planalto and Understanding the Origin of the Modern Amazon Basin with Imaging Radar: (United States)

    Islam, R.; McDonald, K. C.; Azarderakhsh, M.; Campbell, K.; Cracraft, J.; Carnaval, A. C.


    The Amazon basin is a biodiversity biome and plays a significant role into shaping the earth's climate, ocean and atmospheric gases. Understanding the history of the formation of the basin is essential to our understanding of the region's biodiversity loss and response to climate change. Ancient River channels in lowland Amazonia exhibit right angle branching structures as well as intricately intertwined channels. Past research has attributed these characteristic as a result of subsurface faults but makes it difficult to validate this augment due to dense vegetation and sedimentation. We seek to employ remote sensing techniques for examining geomorphological features and the relationship to evolutionary processes that shaped biodiversity in the modern Amazon River Basin. We utilize UAVSAR imagery gathered from the NASA/JPL airborne imaging radar over the Planalto, in the Madre de Dios region of Southeastern Peru in an assessment of the underlying geomorphology, its relationship to the current distribution of vegetation, and geologic processes through deep time. In the late Neogene, the Amazonian lowlands comprised either a series of independent basins or a single sedimentary basin. The Amazonian Planalto is variously described as either erosional surface or a surface of deposition. We employ UAVSAR data collection to assess (1) the utility of these radar data for use in identifying associated geomorphologic features, and (2) UAVSAR's utility in aiding interpretation of ALOS PALSAR and STRM datasets to support a basin-wide characterization. We derive maps of river networks using a canny based edge detection method applied on the UAVSAR backscatter images. We develop an algorithm, which separates the river networks into various catchments based on connected component and then calculates angles at each branch point. We then assess distribution of right angle branching structure throughout the entire region. The results of the analysis will have a major impact on

  11. Volumes of sediment stored in an Alpine catchment using geological, geomorphological and geophysical expertise: Peynin catchment (Queyras, Southern French Alps) (United States)

    Carlier, Benoît; Carlier, Gabriel; Lissak, Candide; Gance, Julien; Malet, Jean-Philippe; Graff, Kevin; Viel, Vincent; Arnaud-Fassetta, Gilles; Fort, Monique; Bétard, François; Madelin, Malika


    The combination of predisposing factors (schist bedrock supplying abundant debris, high slope gradient and strong hillslope-channel connectivity), makes the Upper Guil catchment particularly prone to torrential hazards such as floods or debris flows. The occurrence of "Lombarde easterlies" episodes may generate intense rainfall over short time periods (320 mm in 8 days in June 1957). During such events, the observed damages are mainly related to the sediment transport (fine sediments and metric boulders) in the torrential streams, as in 1946 and 1957, and more recently in 2000, 2008 and 2010. In order to evaluate mountainous hazards in a Global Change context (i.e. climatic and socio-economic), the French funded ANR project SAMCO put the emphasis on the hydrogeomorphological functioning of the Upper Guil catchment. In this context, a sedimentary budget analysis at the Holocene timescale was elaborated for the active Peynin catchment (≈ 15 km2). The volumes of sediments stored on the slopes and in the channels are evaluated using geophysical and geomorphological investigations in order to establish the amount of material potentially mobilized during low frequency/high magnitude flood events. On the basis of intensive fieldwork and GIS mapping (geology and geomorphology), two models of sediment thickness are proposed. The first one, inspired by the work of Schrott et al. (2003), is based on the modelling of the supposed bedrock roof using polynomial functions and GIS modelling (high estimate). The second model is field based and results from a geological and geomorphological analysis of 46 topographic and geologic cross sections (low estimate). To reduce the error margins in sediment thickness estimates, three seismic refraction profiles made in summer 2014 have been interpreted and integrated to these models. The volumes of sediments stored in the Peynin catchment were respectively estimated to 0.423 km3 (high estimate) and 0.171 km3 (low estimate). This

  12. Application Development: AN Interactive, Non-Technical Perspective of the Geology and Geomorphology of the Ouray Perimeter Tail, CO. (United States)

    Allen, H. M.; Giardino, J. R.


    Each year people seek respite from their busy lifestyles by traveling to state or national parks, national forests or wilderness areas. The majority of these parks were established in order to help preserve our natural heritage, including wildlife, forests, and the beauty of landscapes formed from thousands of years of geologic/geomorphologic processes. Whilst being able to enjoy the tranquility of nature, tourists are being robbed of a more in-depth experience as a result of the lack of a geologic background. One such location that attracts a large number of summer tourists is the perimeter trail in Ouray, Colorado. Located in the Southwestern portion of Colorado, Ouray is situated in the beautiful San Juan Mountain range along the "Million Dollar Highway." The Perimeter trail is a six-mile trail loop that circles the city of Ouray. The city is a very popular place for summertime tourism because of its unparalleled scenery. Ouray is situated in an area that is riddled with textbook angular unconformities, metasedimentary, sedimentary, and volcanic rocks. In the study area, The San Juans have been beautifully sculpted by an array of major faulting events, glacial activity and volcanics. With the understanding that technology is ever expanding, we think there is no better way to experience the Perimeter Trail than to have an interactive application that will be both educational as well as interesting. This application is a non-technical way of looking at the geology and geomorphology of the perimeter trail. Additionally, a paper brochure shows the most noteworthy points of interest. The brochure contains a brief geologic history of the San Juan Mountains accompanied with annotated photographs to illustrate the complex geology/geomorphology encountered on the trail. The application is based on an interactive three-dimensional map, which can be zoomed to various scales. The app hosts a locational service that uses the phone's GPS to communicate location of the hiker

  13. The aeolian sedimentary system in the northern Qilian Shan and Hexi Corridor (N-China) - geomorphologic, sedimentologic and climatic drivers (United States)

    Nottebaum, Veit; Lehmkuhl, Frank; Stauch, Georg


    The formation of aeolian deposits depends on the influence of climatic factors but also on non-climatic controls, such as local geomorphological setting and tectonic activity. Unravelling the environmental history needs a careful consideration of a set of sections to capture spatial variability and a detailed investigation of depositing processes and chronology. Along the northern margin of the Qilian Shan mountain range 22 OSL-dated loess and aeolian sand sections and additional surface samples reveal the interactions between climatic, geomorphologic and sedimentologic factors. Thin loess covers (~1-2 m) occur in elevations of 2000 to 3800 m asl, which were mainly accumulated during the Holocene. End-member modelling of loess grain size data exhibits three dominant aeolian transport pathways representing local transport from fluvial storages, dust storm contribution and background dust deposition. Their relative contributions show a clear dependence on geomorphological setting, and additionally, synchronous trends throughout the Holocene. Their relative changes allow conclusions about Holocene environmental conditions. Discontinuous archives (aeolian sand, lacustrine, and alluvial deposition) in the lower forelands of the Qilian Shan show a distinct spatial pattern contrasting western and eastern forelands. The comparison of OSL ages exhibits high sediment accumulation (~2 m/ka) in the drier western part during the Late Glacial, while the lack of Holocene ages indicates sediment discharge / deflation. In contrast, moister areas in the eastern foreland yield scattered Holocene ages. This indicates high sediment dynamics, benefiting from fluvial reworking and thus provided sediment availability. Fluvial sediment supply plays an important role in sediment recycling. Meanwhile, western forelands lack efficient sand sources and fluvial reworking agents. The study exemplifies the complex sedimentary systems acting along mountain to foreland transects which often host

  14. Geomorphological evolution of a fluvial channel after primary lahar deposition: Huiloac Gorge, Popocatépetl volcano (Mexico) (United States)

    Tanarro, L. M.; Andrés, N.; Zamorano, J. J.; Palacios, D.; Renschler, C. S.


    Popocatépetl volcano (19°02' N, 98°62' W, 5424 m) began its most recent period of volcanic activity in December 1994. The interaction of volcanic and glacier activity triggered the formation of lahars through the Huiloac Gorge, located on the northern flank of the volcano, causing significant morphological changes in the channel. The most powerful lahars occurred in April 1995, July 1997 and January 2001, and were followed by secondary lahars that formed during the post-eruptive period. This study interprets the geomorphological evolution of the Huiloac Gorge after the January 2001 lahar. Variations in channel morphology at a 520 m-long research site located mid-way down the gorge were recorded over a 4 year period from February 2002 to March 2005, and depicted in five geomorphological maps (scale 1:200) for 14 February and 15 October 2002, 27 September 2003, 9 February 2004, and 16 March 2006. A GIS was used to calculate the surface area for the landforms identified for each map and detected changes and erosion-deposition processes of the landforms using the overlay function for different dates. Findings reveal that secondary lahars and others types of flows, like sediment-laden or muddy streamflows caused by precipitation, rapidly modified the gorge channel following the January 2001 non-eruptive lahar, a period associated with volcanic inactivity and the disappearance of the glacier once located at the headwall of the gorge. Field observations also confirmed that secondary flows altered the dynamics and geomorphological development of the channel. These flows incised and destroyed the formations generated by the primary lahars (1997 and 2001), causing a widening of the channel that continues today. After February 2004, a rain-triggered lahar and other flows infilled the channel with materials transported by these flows. The deposits on the lateral edges of the channel form terraces. A recent lull in lahar activity contrasts with the increasing instability of

  15. Spatial impact and triggering conditions of the exceptional hydro-geomorphological event of December 1909 in Iberia (United States)

    Pereira, S.; Ramos, A. M.; Zêzere, J. L.; Trigo, R. M.; Vaquero, J. M.


    According to the DISASTER database the 20-28 December 1909 event was the hydro-geomorphologic event with the highest number of flood and landslide cases that occurred in Portugal in the period 1865-2010 (Zêzere et al., 2014). This event also caused important social impacts over the Spanish territory, especially in the Douro Basin, having triggered the highest floods in more than 100 years at the river's mouth in the city of Oporto. This work has a dual purpose: (i) to characterize the spatial distribution and social impacts of the December 1909 hydro-geomorphologic DISASTER event over Portugal and Spain; (ii) to analyse the meteorological conditions that triggered the event and the spatial distribution of the precipitation anomalies. Social impacts that occurred in Portugal were obtained from the Disaster database (Zêzere et al., 2014) whereas the data collection for Spain was supported by the systematic analysis of Spanish daily newspapers. In addition, the meteorological conditions that triggered the event are analysed using the 20th Century Reanalysis data set from NOAA and precipitation data from Iberian meteorological stations. The Iberian Peninsula was spatially affected during this event along the SW-NE direction spanning from Lisbon, Santarém, Oporto, and Guarda (in Portugal), to Salamanca, Valladolid, Zamora, Orense, León, and Palencia (in Spain). In Iberia, 134 DISASTER cases were recorded (130 flood cases; 4 landslides cases) having caused 89 casualties (57 due to floods and 32 due to landslides) and a further total of 3876 affected people, including fatalities, injured, missing, evacuated, and homeless people. This event was associated with outstanding precipitation registered at Guarda (Portugal) on 22 December 1909 and unusual meteorological conditions characterized by the presence of a deep low-pressure system located over the NW Iberian Peninsula with a stationary frontal system striking the western Iberian Peninsula. The presence of an upper

  16. Using a Geospatial Model to Relate Fluvial Geomorphology to Macroinvertebrate Habitat in a Prairie River—Part 1: Genus-Level Relationships with Geomorphic Typologies

    Directory of Open Access Journals (Sweden)

    Anna G. N. Meissner


    Full Text Available Modern river ecosystems undergo constant stress from disturbances such as bank stabilization, channelization, dams, and municipal, agricultural, and industrial water use. As these anthropogenic water requirements persist, more efficient methods of characterizing river reaches are essential. Benthic macroinvertebrates are helpful when evaluating fluvial health, because they are often the first group to react to contaminants that can then be transferred through them to other trophic levels. Hence, the purpose of this research is to use a geospatial model to differentiate instream macroinvertebrate habitats, and determine if the model is a viable method for stream evaluation. Through the use of ArcGIS and digital elevation models, the fluvial geomorphology of the Qu’Appelle River in Saskatchewan (SK was assessed. Four geomorphological characteristics of the river were isolated (sinuosity, slope, fractal dimension, and stream width and clustered through Principle Component Analysis (PCA, yielding sets of river reaches with similar geomorphological characteristics, called typologies. These typologies were mapped to form a geospatial model of the river. Macroinvertebrate data were aligned to the locations of the typologies, revealing several relationships with the fluvial geomorphology. A Kruskal-Wallis analysis and post hoc pairwise multiple comparisons were completed with the macroinvertebrate data to pinpoint significant genera, as related to the geospatial model.

  17. A semi-automated approach for mapping geomorphology of El Bardawil Lake, Northern Sinai, Egypt, using integrated remote sensing and GIS techniques

    Directory of Open Access Journals (Sweden)

    Nabil Sayed Embabi


    Full Text Available Among the other coastal lakes of the Mediterranean northern coast of Egypt, Bardawil Lake is a unique lagoon, as it is fed only by seawater. The lagoon is composed of two main basins, and several other internal small basins interconnected to one another. Although the general geomorphologic characteristics are treated in some regional studies, we used a semi-automated approach based on a wide variety of digital image processing for mapping the major geomorphological landforms of the lake on a medium scale of 1:250,000. The approach is based primarily on data fusion of Landsat ETM+ image, and validated by other ancillary spatial data (e.g. topographic maps, Google images and GPS in situ data. Interpretations of high resolution space images by Google Earth and the large-scale topographic maps (1:25,000, in specific, revealed new microforms and some detailed geomorphologic aspects with the aid of GPS measurements. Small sand barriers, submerged sand dunes, tidal channels, fans and flats, and micro-lagoons are the recurrent forms in the lake. The approach used in this study could be widely applied to study the low-lying coastal lands along the Nile Delta. However, it is concluded from geological data and geomorphologic aspects that Bardawil Lake is of a tectonic origin; it was much deeper than it is currently, and has been filled with sediments mostly since the Flandrian transgression (∼8–6 ka bp.

  18. Abstracts of Papers Presented at the International Symposium on Time, Frequency and Dating in Geomorphology Held in Bratislava (Czechoslovakia) on 16- 21 June 1992 (United States)


    J., JULIAN, A.: Archaeological dating, geomorphological reconstructions and palaeoclimatic correlations in northern Spain...material, under Mediterranean climatic conditions, in Tarragona, Spain, were dated. The analyses also included micromorphology and stable isotopes. Age...correlation of archaeological findings with biostratigraphically treated sequences. Our data demonstrate a reasonable relationship between the relief changes

  19. Biodiversity impact of the aeolian periglacial geomorphologic evolution of the Fontainebleau Massif (France) (United States)

    Thiry, M.; Liron, M. N.


    Landscape features The geomorphology of the Fontainebleau Massif is noteworthy for its spectacular narrow ridges, up to 10 km long and 0.5 km wide, armored by tightly cemented sandstone lenses and which overhang sandy depressions of about 50m. Denudation of the sandstone pans lead to a highly contrasted landscape, with sandstone ridges ("platières") towering sandy depressions ("vallées") and limestone plateaus ("monts"). This forms the geological frame of the spectacular sceneries of the Fontainebleau Massif (Thiry & Liron, 2007). Nevertheless, there is little know about the erosive processes that have built-up these landscapes. Periglacial processes, and among them aeolian ones, appear significant in the development of the Fontainebleau Massif physiography. The periglacial aeolian geomorphology Dunes and dune fields are known since long and cover about 15% to 25% of the Fontainebleau Massif. The aeolian dunes developed as well on the higher parts of the landscape, as well as in the lower parts of the landscape. The dunes are especially well developed in the whole eastern part of the massif, whereas the western part of the massif is almost devoid of dunes. Nevertheless, detailed mapping shows that dunes can locally be found in the western district, they are of limited extension, restricted to the east facing backslope of outliers. Loamy-sand covers the limestone plateaus of the "monts". The loam cover is of variable thickness: schematically thicker in the central part of the plateaus, where it my reach 3 m; elsewhere it may thin down to 0,20-0,30 m, especially at the plateau edges. Blowout hollows are "negative" morphologies from where the sand has been withdrawed. Often these blowouts are decametric sized and well-delimited structures. Others, more complex structures, are made up of several elongated hectometric hollows relaying each other from and which outline deflation corridor more than 1 km long. A characteristic feature of these blowout hollows is the

  20. Photogrammetric Methodology for the Production of Geomorphologic Maps: Application to the Veleta Rock Glacier (Sierra Nevada, Granada, Spain

    Directory of Open Access Journals (Sweden)

    José Jesús Guerrero


    Full Text Available In this paper we present a stereo feature-based method using SIFT (Scale-invariant feature transform descriptors. We use automatic feature extractors, matching algorithms between images and techniques of robust estimation to produce a DTM (Digital Terrain Model using convergent shots of a rock glacier.The geomorphologic structure observed in this study is the Veleta rock glacier (Sierra Nevada, Granada, Spain. This rock glacier is of high scientific interest because it is the southernmost active rock glacier in Europe and it has been analyzed every year since 2001. The research on the Veleta rock glacier is devoted to the study of its displacement and cartography through geodetic and photogrammetric techniques.

  1. The sky is the limit? 20 years of small-format aerial photography taken from UAS for monitoring geomorphological processes (United States)

    Marzolff, Irene


    One hundred years after the first publication on aerial photography taken from unmanned aerial platforms (Arthur Batut 1890), small-format aerial photography (SFAP) became a distinct niche within remote sensing during the 1990s. Geographers, plant biologists, archaeologists and other researchers with geospatial interests re-discovered the usefulness of unmanned platforms for taking high-resolution, low-altitude photographs that could then be digitized and analysed with geographical information systems, (softcopy) photogrammetry and image processing techniques originally developed for digital satellite imagery. Even before the ubiquity of digital consumer-grade cameras and 3D analysis software accessible to the photogrammetric layperson, do-it-yourself remote sensing using kites, blimps, drones and micro air vehicles literally enabled the questing researcher to get their own pictures of the world. As a flexible, cost-effective method, SFAP offered images with high spatial and temporal resolutions that could be ideally adapted to the scales of landscapes, forms and distribution patterns to be monitored. During the last five years, this development has been significantly accelerated by the rapid technological advancements of GPS navigation, autopiloting and revolutionary softcopy-photogrammetry techniques. State-of-the-art unmanned aerial systems (UAS) now allow automatic flight planning, autopilot-controlled aerial surveys, ground control-free direct georeferencing and DEM plus orthophoto generation with centimeter accuracy, all within the space of one day. The ease of use of current UAS and processing software for the generation of high-resolution topographic datasets and spectacular visualizations is tempting and has spurred the number of publications on these issues - but which advancements in our knowledge and understanding of geomorphological processes have we seen and can we expect in the future? This presentation traces the development of the last two decades

  2. Flood hazard of the Somma-Vesuvius region based on historical (19-20th century and geomorphological data

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    Giuliana Alessio


    Full Text Available This paper presents a preliminary susceptibility map of the flood hazard for the Somma-Vesuvius volcanic district, worked out by means of multi-disciplinary historical, geological, geomorphological and rainfall data processing. It is well known that the Somma-Vesuvius volcano, due to its explosive volcanism and the dense urbanization of the surrounding area, with a population exceeding 650,000 is one of the most dangerous active volcanoes of the world. Although this area has been extensively studied from the volcanological point of view with regards to its volcanic hazard, there are currently not many detailed studies about its flood hazard factors, despite the fact that, in the last century, many intense rainfall events in this area have produced several floods that invaded the surrounding plains affecting towns and roads, and causing much damages and loss of lives. Accordingly, in this paper high-resolution DEM (5×5 m pixel and detailed geomorphological maps of the whole area have been analyzed and processed in GIS environment, carrying out a comparative study of the present-day morphology and the morphology of the 1900’s volcanic edifice, including changes of infrastructures and buildings throughout the last century. These results, together with historical chronicles data and the rainfall accurate data for all flood events, have been processed in this paper for highlighting the drainage basins areas of Somma-Vesuvius where the flood phenomena could be more probable in the future, working out a preliminary zoning map, also suggesting in which sectors interventions useful for mitigation of flood risk should be implemented.

  3. Small-scale variability in geomorphological settings influences mangrove-derived organic matter export in a tropical bay (United States)

    Signa, Geraldina; Mazzola, Antonio; Kairo, James; Vizzini, Salvatrice


    Organic matter (OM) exchanges between adjacent habitats affect the dynamics and functioning of coastal systems, as well as the role of the different primary producers as energy and nutrient sources in food webs. Elemental (C, N, C : N) and isotope (δ13C) signatures and fatty acid (FA) profiles were used to assess the influence of geomorphological setting in two climatic seasons on the export and fate of mangrove OM across a tidally influenced tropical area, Gazi Bay (Kenya). The main results indicate that tidal transport, along with riverine runoff, plays a significant role in the distribution of mangrove organic matter. In particular, a marked spatial variability in the export of organic matter from mangroves to adjacent habitats was due to the different settings of the creeks flowing into the bay. Kinondo Creek acted as a mangrove retention site, where export of mangrove material was limited to the contiguous intertidal area, while Kidogoweni Creek acted as a flow-through system, from which mangrove material spreads into the bay, especially in the rainy season. This pattern was evident from the isotopic signature of primary producers, which were more 13C-depleted in the Kinondo Creek and nearby, due to the lower dilution of the dissolved inorganic carbon (DIC) pool, typically depleted as an effect of intense mangrove mineralisation. Despite the trapping efficiency of the seagrass canopy, suspended particulate OM showed the important contribution of mangroves across the whole bay, up to the coral reef, as an effect of the strong ebb tide. Overall, mixing model outcomes indicated a widespread mixed contribution of both allochthonous and autochthonous OM sources across Gazi Bay. Moreover, FAs indicated a notable contribution of brown macroalgae and bacteria in both sediment and suspended pools. These results suggest that ecological connectivity in Gazi Bay is strongly influenced by geomorphological setting, which may have far-reaching consequences for the

  4. Oceanic Transform Fault-Zone Geomorphology in the Gulf of California from High-Resolution Bathymetric Data (United States)

    Hilley, G. E.; Aron, F.; Baden, C. W.; Castillo, C. M.; Johnstone, S. A.; Nevitt, J. M.; McHargue, T.; Paull, C. K.; Sare, R.; Shumaker, L.; Young, H.


    We use high-resolution, deep-water bathymetry to examine the structure of, and offset along, transform faults in the Gulf of California. These data provide detailed observations of fault-zone geomorphology of an active transform fault hosted in an area transitioning from continental to oceanic crust. Bathymetric data were collected by an autonomous underwater vehicle deployed by the Monterey Bay Aquarium Research Institute in 2012. Dense ocean-bottom point clouds allowed construction of an ~1-m-resolution digital terrain model, which provides comparable spatial resolution to early airborne laser swath mapping surveys. The data reveal a set of complex, multi-stranded fault zones, whose morphologies suggest a temporal migration of deformation between individual strands contained within an up to 1 km wide zone, similar to complex fault zones observed within continental crust in subaerial environments. Individual fault strands show restraining steps that create positive relief along the ocean floor in their vicinity. Although the depositional nature of these deep-water systems makes identification of offset features challenging, we found a series of offset fans along a fault strand with consistent right-lateral offsets of 17-21 m. These are likely multi-event offsets, given the length of the transform segments and magnitudes of historically recorded earthquakes in the region. The consistency of these multi-event offsets suggests that an external process predating the displacement of the fans, such as seismic shaking due to large earthquakes, may be responsible for the synchroneity of these features. Our study demonstrates that the fault-zone geomorphology of oceanic transform faults in the Gulf of California bears resemblance to that of terrestrial strike-slip faults hosted in continental crust, and that high-resolution, deep water bathymetry can provide information about the earthquake history of these environments.

  5. Impact of geology and geomorphology on fluoride contaminated groundwater in hard rock terrain of India using geoinformatics approach (United States)

    Shekhar, Shashank; Ghosh, Mili; Pandey, A. C.; Tirkey, Anamika Shalini


    The present study demonstrates a GIS-based spatial evaluation of fluoride contamination (FC) in groundwater vis-a-vis geology and geomorphology of the area using analytical hierarchy process and weighted sum method in Palamu district of Jharkhand. The integration and analyses of the various thematic databases along with the field sampled fluoride data proved useful in delineating the FC zones. The FC index ranged between 141 and 707, and was classified into four zones, viz., low, moderate, high, and very high zones of FC. The FC index map showed that a total of 49.75% of the study area lies between high to very high FC zone. The very high FC zone is found in the moderately weathered plateau with granitic terrain, whereas the high and moderately FC zones covering 49.31 and 36.41% of the study area are dominated by plateau weathered shallow, pediment-inselberg complex, pediplain moderately weathered, pediplain shallow weathered, and inselberg which have high fluoride. The lowest FC zone covers an area of 193.27 sq. km (13.84%). The spatial analysis of geology with fluoride showed that groundwater within granitic gneiss exhibits high FC followed by granitoid gneiss and alluvium. Geomorphologically highest FC was recorded in plateau weathered moderate (91.67%) followed by plateau weathered shallow (71.43%), flood plain (41.76%), inselberg (27.27%), and pediment (25%). The spatial analysis of groundwater yield with fluoride showed that regions having good yield exhibit maximum FC thereby accelerating the vulnerability of the population to fluorosis.

  6. Geomorphological and sedimentological characteristics of cyclone-generated landforms and washover deposits along the coasts of NW Australia (United States)

    May, Simon Matthias; Engel, Max; Brückner, Helmut; Pint, Anna; Kelletat, Dieter; Scheffers, Anja; Squire, Peter


    Palaeotempestology, the study of prehistoric storms, uses sedimentary evidence to enlarge the temporal frame of storm occurrence patterns given by historical records. Different sedimentary archives storing traces of tropical cyclone impact (washover fans and sediments, beach ridge systems) were investigated along the coasts of the Exmouth Gulf and the NW Cape(W Australia) in order to evaluate their use for palaeotempestological research. (1) Along the W coast of the Exmouth Gulf, distinct lobate washover fans exhibit washover terraces, channel systems and delta-type sedimentation patterns. Their stratigraphy consists of shell debris layers, sand, coarse coral fragments and entire shells. Multiple reactivation of the washover fans is inferred from their complex pattern of accumulation and incision and a minimum of three palaeosols, each of them indicating one depositional event and a subsequent period of geomorphologic stability. (2) In Giralia Bay, S Exmouth Gulf, sandy chenier-like beach ridges characterize the landward boundary of extensive mud flats. Their geomorphology and stratigraphical architecture reflect the influence of intermittent phases of morphodynamic activity due to littoral-type processes and are assumed to record recurring cyclone impact. (3) Along the W coast of the NW Cape, subrecent tsunami sediments detected in back-barrier archives contain reworked foraminifers from the shelf and the littoral zone and are most likely related to the 1994 Java Tsunami. Below, several thin clastic sand layers intercalate carbonate mud sediments. In contrast to the mud units, most of the sandy layers are reflected by increased mean grain size and contain reworked foraminifers from the shelf and littoral zone. Underlying mud sediments and mangrove remains reflect coastal and palaeoenvironmental changes on Holocene time scales. Our preliminary findings suggest that the investigated sedimentary archives have a high potential for improving extreme wave histories

  7. Gully erosion and landslide reactivation in the Central Italian Apennine: new data from dendrochronology and quantitative geomorphology (United States)

    Bollati, Irene; Della Seta, Marta; Del Monte, Maurizio; Fredi, Paola; Lupia Palmieri, Elvidio; Pelfini, Manuela


    The Central Italian Appennine area is widely affected by "calanchi" badlands, whose main geomorphic agent is the water runoff on the widespread clayey lithologies: in the study area (geomorphosites of Crete di Arbia, Asciano, Siena) the Pliocene clay constitute an ideal substratum for the development of water erosion landforms and gravitational processes. The integrated approach between dendrogeomorphology and quantitative geomorphology has allowed monitoring and reconstructing the development of these badland landforms. Most of the rapidly evolving slopes of the area underwent strong conifer reforestation. For dendrogeomorphology analysis sampling has been performed on 67 trees of the Pinus Pinea, Cupressus sempervirens and Thuja occidentalis species, on slopes affected by gravitational movements and water erosion, in order to identify annual ring growth anomalies, compression wood and exposition of roots. The main goal was reconstructing the correspondence between the trees indications and the estimated denudation rates due to surface running water erosion and mass movements. A general trend of negative anomalies has been identified through relatively cross-dated chronologies, in correspondence of multi-years compression wood periods, even if trees local behaviours are not unusual. During the 90's the Pinus Pinea shows a continuous growth reduction and in the same period a systematic increase in mass movement diffusion was recorded during geomorphological surveys. Thus since 1993 several monitoring stations on badland slopes have been equipped with erosion pins. Quantitative data from monitoring stations, compared to pluviometric series, indicated another critical phase of denudation in 2003, that was supported by dendrochronological data. The integrated approach allowed obtaining continuous series of data by direct monitoring and precious information for the period preceding the field measurements. This kind of approach, applicable in many contexts, could be

  8. Geomorphological map of the Afekan Crater region, Titan: Terrain relationships in the equatorial and mid-latitude regions (United States)

    Malaska, Michael J.; Lopes, Rosaly M. C.; Williams, David A.; Neish, Catherine D.; Solomonidou, Anezina; Soderblom, Jason M.; Schoenfeld, Ashley M.; Birch, Sam P. D.; Hayes, Alex G.; Le Gall, Alice; Janssen, Michael A.; Farr, Thomas G.; Lorenz, Ralph D.; Radebaugh, Jani; Turtle, Elizabeth P.


    We carried out geomorphological mapping in a mid-latitude area surrounding the Afekan Crater region on Titan. We used Cassini RADAR (Synthetic Aperture Radar mode) data as the basemap, supplemented by Cassini RADAR microwave emissivity, Imaging Science Subsystem (ISS) infrared data, Visual and Infrared Mapping Spectrometer (VIMS) spectral images, and topography derived from Synthetic Aperture Radar (SAR). Mapping was done at a spatial scale of 300 m/pixel, which corresponds to a map scale of 1:800,000. We describe multiple terrain units and their spatial relations. We describe five broad classes of units that are in agreement with previous mapping efforts: crater, labyrinth, hummocky/mountainous, plains, and dune terrain classes. We subdivide these into seven crater units, four hummocky/mountainous units, six plains units, and three dunes units. Our results show that plains are the dominant class of terrain unit in Titan's mid latitudes. Of the plains units, the undifferentiated plains are the largest by total areal extent in the mapped region, accounting for over 45% of the mapped area. We developed a stratigraphic sequence that has the hummocky/mountainous and labyrinth terrains as the oldest units. The observed properties of the hummocky/mountainous terrain are consistent with fractured water ice materials, while the labyrinth terrains are consistent with organic materials. The youngest units are the dune units and streak-like plains units, with the undifferentiated plains units being of intermediate age. The microwave emissivity of the undifferentiated plains and dune units are consistent with organic materials. Given their properties and stratigraphic placement, we conclude that the hummocky/mountainous terrains are most consistent with the presumed crustal materials of Titan. The plains materials are consistent with deposits resulting from the transport and emplacement of organic-rich materials predominantly by aeolian mechanisms. Our geomorphological mapping

  9. Actual extension of sinkholes: Considerations about geophysical, geomorphological, and field inspection techniques in urban planning projects in the Ebro basin (NE Spain) (United States)

    Pueyo Anchuela, Ó.; Pocoví Juan, A.; Casas-Sainz, A. M.; Ansón-López, D.; Gil-Garbi, H.


    Aerial photographs, historical cartographies, and field inspection are useful tools in urban planning design on mantled karst because they permit a wide time interval to be analyzed. In the case of Zaragoza city, several works have confirmed the interest of these approaches in configuring the urban planning code and therefore represent a promising technique. Nevertheless, some caveats should be taken into account when using this kind of information. A detailed analysis is presented comparing (in a case study from the surroundings of Zaragoza) geomorphological, historical analysis, and field inspection with geophysical data. Field inspection in a noncultivated area permits the constraint of the presence of karst indicators below the geomorphological resolution of aerial photographs and shows results consistent with geophysical surveys. The studied case shows an inner zone coinciding with the sinkhole mapped from aerial photographs that correlates with changes in the position of the substratum and changes in thickness of alluvial sediments. The integrated analysis permits us to define an external subsidence ring around the geomorphological sinkhole whose surface is twice the size of the inner zone. This outer ring is indicated by geometrical changes in GPR profiles, increases of thickness of the conductive shallower unit toward the collapse, and small collapses on marginal cracks. These results support the higher extension of karst hazards linked to sinkholes with respect to their geomorphological expression and the needed detailed analysis to constrain the real sinkhole size or the use of security radii surrounding this surficial evidence when geomorphological data is used for the hazard analyses or the urban planning at karstic zones.

  10. Novel 3D imaging techniques for improved understanding of planetary surface geomorphology. (United States)

    Muller, Jan-Peter


    Understanding the role of different planetary surface formation processes within our Solar System is one of the fundamental goals of planetary science research. There has been a revolution in planetary surface observations over the past decade for Mars and the Moon, especially in 3D imaging of surface shape (down to resolutions of 75cm) and subsequent correction for terrain relief of imagery from orbiting and co-registration of lander and rover robotic images. We present some of the recent highlights including 3D modelling of surface shape from the ESA Mars Express HRSC (High Resolution Stereo Camera), see [1], [2] at 30-100m grid-spacing; and then co-registered to HRSC using a resolution cascade of 20m DTMs from NASA MRO stereo-CTX and 0.75m DTMs from MRO stereo-HiRISE [3]. This has opened our eyes to the formation mechanisms of megaflooding events, such as the formation of Iani Vallis and the upstream blocky terrain, to crater lakes and receding valley cuts [4]. A comparable set of products is now available for the Moon from LROC-WA at 100m [5] and LROC-NA at 1m [6]. Recently, a very novel technique for the super-resolution restoration (SRR) of stacks of images has been developed at UCL [7]. First examples shown will be of the entire MER-A Spirit rover traverse taking a stack of 25cm HiRISE to generate a corridor of SRR images along the rover traverse of 5cm imagery of unresolved features such as rocks, created as a consequence of meteoritic bombardment, ridge and valley features. This SRR technique will allow us for ˜400 areas on Mars (where 5 or more HiRISE images have been captured) and similar numbers on the Moon to resolve sub-pixel features. Examples will be shown of how these SRR images can be employed to assist with the better understanding of surface geomorphology. Acknowledgements: The research leading to these results has received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under PRoViDE grant agreement n° 312377

  11. Modelling changes in the coastal geomorphology of Unst, Shetland and the implications for understanding High to Late Medieval harbour changes in the Norse North Atlantic (United States)

    Preston, John; Dugmore, Andrew; Newton, Anthony; Mudd, Simon


    The Norse settlement of the North Atlantic islands relied upon a network of harbours that also played a key role in the development of North European economies through the late Middle Ages. However, many of these harbours fell into disuse, their locations are uncertain and the reasons for this are unclear. A crucial geomorphological characteristic of a successful harbour is structural equilibrium. A harbour must have physical stability (or a dynamic equilibrium in the case of a beach) for boats to use it safely season to season, year on year. In the absence of a major civil engineering effort, something that was not possible in the pre-modern Atlantic islands, the geomorphology of a harbour is a key indicator of its physical equilibrium (or otherwise). Should the harbour be located on a changeable coastline (or one that becomes changeable) it may become unviable. Conversely, a harbour may be located on a coastline stable over centennial timescales, where little geomorphological change occurs, infrastructure can endure and many aspects of the physical environment remain predictable. The geomorphological setting of Norse harbours in the Atlantic is variable, with contrasting landform stability over short, medium and long time scales. We assess geomorphological change on the island of Unst, the most northerly of the British Isles, a coastline used by the Norse as well as earlier and later societies. This island offers a complex coastline of deep fjords and arcuate embayments and thus significant differences in forces acting upon the coastline. There is also evidence for instability in the beaches used by the Norse that could have been driven by the changes in climate conditions from the Medieval Climatic Anomaly to the Little Age and the present day. We model coastlines using the sediment dynamics model MIKE21. Model results agree well with the location of extant sandy beaches on Unst, but model runs with modern environmental drivers also build sandy beaches where

  12. Soil and geomorphological parameters to characterize natural environmental and human induced changes within the Guadarrama Range (Central Spain) (United States)

    Schmid, Thomas; Inclán-Cuartas, Rosa M.; Santolaria-Canales, Edmundo; Saa, Antonio; Rodríguez-Rastrero, Manuel; Tanarro-Garcia, Luis M.; Luque, Esperanza; Pelayo, Marta; Ubeda, Jose; Tarquis, Ana; Diaz-Puente, Javier; De Marcos, Javier; Rodriguez-Alonso, Javier; Hernandez, Carlos; Palacios, David; Gallardo-Díaz, Juan; Fidel González-Rouco, J.


    Mediterranean mountain ecosystems are often complex and remarkably diverse and are seen as important sources of biological diversity. They play a key role in the water and sediment cycle for lowland regions as well as preventing and mitigating natural hazards especially those related to drought such as fire risk. However, these ecosystems are fragile and vulnerable to changes due to their particular and extreme climatic and biogeographic conditions. Some of the main pressures on mountain biodiversity are caused by changes in land use practices, infrastructure and urban development, unsustainable tourism, overexploitation of natural resources, fragmentation of habitats, particularly when located close to large population centers, as well as by pressures related toclimate change. The objective of this work is to select soil and geomorphological parameters in order to characterize natural environmental and human induced changes within the newly created National Park of the Sierra de Guadarrama in Central Spain, where the presence of the Madrid metropolitan area is the main factor of impact. This is carried out within the framework of the Guadarrama Monitoring Network (GuMNet) of the Campus de ExcelenciaInternacionalMoncloa, where long-term monitoring of the atmosphere, soil and bedrock are priority. This network has a total of ten stations located to the NW of Madrid and in this case, three stations have been selected to represent different ecosystems that include: 1) an alluvial plain in a lowland pasture area (La Herreria at 920 m a.s.l.), 2) mid mountain pine-forested and pasture area (Raso del Pino at 1801 m a.s.l.) and 3) high mountain grassland and rock area (Dos Hermanas at 2225 m a.s.l.). At each station a site geomorphological description, soil profile description and sampling was carried out. In the high mountain area information was obtained for monitoring frost heave activity and downslope soil movement. Basic soil laboratory analyses have been carried out

  13. Integrative geomorphological mapping approach for reconstructing meso-scale alluvial fan palaeoenvironments at Alborz southern foothill, Damghan basin, Iran (United States)

    Büdel, Christian; Majid Padashi, Seyed; Baumhauer, Roland


    Alluvial fans and aprons are common depositional features in general Iranian geomorphology. The countries major cities as well as settlements and surrounding area have often been developed and been built up on this Quaternary sediment covers. Hence they periodically face the effects of varying fluvial and slope-fluvial activity occurring as part of this geosystem. The Geological Survey of Iran therefore supports considerable efforts in Quaternary studies yielding to a selection of detailed mapped Quaternary landscapes. The studied geomorphologic structures which are settled up around an endorheic basin in Semnan Province represent a typical type of landform configuration in the area. A 12-km-transect was laid across this basin and range formation. It is oriented in north-south direction from the southern saltpan, called "Kavir-e-Haj Aligholi"/"Chah-e-Jam" ("Damghan Kavir"), across a vast sandy braided river plain, which is entering from the north east direction of the city of Shahroud. At its northern rim it covers alluvial sediment bodies, which are mainly constituted by broad alluvial aprons, fed by watersheds in Alborz Mountains and having their genetic origins in Mio-/Pliocene times. During this study a fully analytical mapping system was used for developing a geodatabase capable of integrating geomorphological analyses. Therefore the system must provide proper differentiation of form, material and process elements as well as geometric separation. Hence the German GMK25 system was set up and slightly modified to fit to the specific project demands. Due to its structure it offers most sophisticated standards and scale independent hierarchies, which fit very well to the software-determinated possibilities of advanced geodatabase applications. One of the main aspects of mapping Quaternary sediments and structures is to acquire a proper description and systematic correlation and categorization of the belonging mapping-objects. Therefore the team from GSI and

  14. Multitemporal 3D data capturing and GIS analysis of fluvial processes and geomorphological changes with terrestrial laser scanning (United States)

    Hämmerle, Martin; Forbriger, Markus; Höfle, Bernhard


    LiDAR is a state of the art method for directly capturing 3D geodata. A laser beam is emitted in a known direction. The time of flight of the laser pulse is recorded and transformed into the distance between sensor and scanned object. The result of the scanning process is a 3D laser point cloud densely covering the surveyed area. LiDAR is used in a vast variety of research fields. In this study, the focus is on the application of terrestrial laser scanning (TLS), the static and ground-based LiDAR operation, in a multitemporal analysis of fluvial geomorphology. Within the framework of two study projects in 2011/2012, two TLS surveys were carried out. The surveys covered a gravel bar of about 150 m × 25 m size in a side branch of the Neckar River near Heidelberg (49°28'36''N, 8°34'32''E) located in a nature reserve with natural river characteristics. The first survey was performed in November 2011, the second in June 2012. Due to seasonally changing water levels, the gravel bar was flooded and the morphology changed. For the field campaigns, a Riegl VZ-400 was available. Height control points and tie points for registration and georeferencing were obtained with a total station and GPS equipment. The first survey was done from 6 scan positions (77 million points) and the second from 5 positions (89 million points). The point spacing for each single scan was set to 3 mm at 10 m distance. Co-registration of the individual campaigns was done via an Iterative Closest Point algorithm. Thereafter, co-registration and fine georeferencing of both epochs was performed using manually selected tie points and least-squares adjustment. After filtering of vegetation in the 3D point cloud in the software OPALS, a digital terrain model (DTM) with 0.25 m by 0.25 m cell size was generated for each epoch. A difference raster model of the two DTMs for assessing the changes was derived excluding water surface areas using the signal amplitude recorded for each echo. From the mean

  15. Geomatics techniques applied to time series of aerial images for multitemporal geomorphological analysis of the Miage Glacier (Mont Blanc). (United States)

    Perotti, Luigi; Carletti, Roberto; Giardino, Marco; Mortara, Giovanni


    The Miage glacier is the major one in the Italian side of the Mont Blanc Massif, the third by area and the first by longitudinal extent among Italian glaciers. It is a typical debris covered glacier, since the end of the L.I.A. The debris coverage reduces ablation, allowing a relative stability of the glacier terminus, which is characterized by a wide and articulated moraine apparatus. For its conservative landforms, the Miage Glacier has a great importance for the analysis of the geomorphological response to recent climatic changes. Thanks to an organized existing archive of multitemporal aerial images (1935 to present) a photogrammetric approach has been applied to detect recent geomorphological changes in the Miage glacial basin. The research team provided: a) to digitize all the available images (still in analogic form) through photogrammetric scanners (very low image distortions devices) taking care of correctly defining the resolution of the acquisition compared to the scale mapping images are suitable for; b) to import digitized images into an appropriate digital photogrammetry software environment; c) to manage images in order, where possible, to carried out the stereo models orientation necessary for 3D navigation and plotting of critical geometric features of the glacier. Recognized geometric feature, referring to different periods, can be transferred to vector layers and imported in a GIS for further comparisons and investigations; d) to produce multi-temporal Digital Elevation Models for glacier volume changes; e) to perform orthoprojection of such images to obtain multitemporal orthoimages useful for areal an planar terrain evaluation and thematic analysis; f) to evaluate both planimetric positioning and height determination accuracies reachable through the photogrammetric process. Users have to known reliability of the measures they can do over such products. This can drive them to define the applicable field of this approach and this can help them to

  16. Soil-geomorphology and “wet” cycles in the Holocene record of North-Central Mexico (United States)

    Butzer, Karl W.; Abbott, James T.; Frederick, Charles D.; Lehman, Paul H.; Cordova, Carlos E.; Oswald, John F.


    The distinction between the impact of climatic periodicities or land-use practices on soil erosion is an important issue for Pre-Hispanic and Colonial Mexico. That question can best be addressed by first documenting the dynamics of changing "wet" cycles during the Holocene in the central Mexican region between the northern limits of Pre-Hispanic agriculture and its southern margins in northwestern Chihuahua. Consequently the Laguna Project targeted a 125,000 km 2 sector of North-Central Mexico, 250 km from north to south and 500 km from east to west, from Saltillo to Durango. Some 40 sedimentary profiles with multiple cumulic soils were studied in the field and laboratory, supported by 163 conventional 14C and AMS dates on charcoal and soil humates. We distinguish: (1) wet floodplains (with humic paleosols, redox phenomena reflecting high water tables, channel-ponding sequences, and interbedded tufas) that imply aquifer recharge, sustained base flow, and mainly low-energy conditions; and (2) high-energy pulses of discharge that mobilized cobble gravels or forced channel entrenchment ("gullying") and were tied to episodic, excessive rains that promoted valley and slope instability. In between such "wet" cycles and recurrent disequilibrium events, climate was similar to today, probably less humid, with limited geomorphologic change or slow soil formation. "Wet" cycles were rare at the end of the Pleistocene, but prominent during the Holocene. Disequilibrium proxies became common and dramatic after 2500 BP. The drainages from the Eastern and Western Sierra Madres responded in phase, but varied in detail. Around AD 1050-1200 "natural" erosion led to loss of soil organic carbon, as alternating severe droughts and heavy rains destroyed the ground cover and led to ecological aridification, well before arrival of Spanish miners and settlers. The evidence that human activity triggered Pre-Hispanic or Colonial erosion in Central Mexico should therefore be re

  17. The Crati River Basin: geomorphological and stratigraphical data for the Plio–Quaternary evolution of northern Calabria, South Apennines, Italy

    Directory of Open Access Journals (Sweden)

    Robustelli Gaetano


    Full Text Available In this paper, we present the results of an integrated geomorphological and stratigraphical study carried out in the eastern side of the Crati River valley (northern Calabria, South Italy. This area is characterized by the occurrence of three order palaeosurfaces that, along with low-sloping palaeovalleys and structural landforms, are striking features of the landscape. The relationships between morpho-tectonic and sedimentary evolution of the Crati Basin has been assessed through sandstone detrital modes, morphostratigraphy and geomorphological correlation with adjacent areas. The two main unconformity surfaces that typify the Quaternary fill were correlated to different steps of landscape evolution. The presence of both erosional and depositional palaeosurfaces has been a useful marker for reconstructing sedimentary and morphogenetic events, and hence to detect drainage network evolution and changes in source sediment area. In particular, we recognized that the study area experienced, during the late Pliocene–Early Pleistocene a period of sub-aerial landscape modelling as suggested by low-sloping palaeovalleys and related fluvial deposits (1st Order Palaeosurface. At that time, the source of the detrital constituents of the PPS Unit sandstones was mainly from the Sila Massif. The onset of Coastal Range identification and uplift (Early Pleistocene marks a change in the geomorphic scenario with tectonic driven stream incision and valley development along the eastern side of Coastal Range, along with the occurrence of depositional and erosional landsurfaces (2nd Order Palaeosurface at footslopes. During this period, the Coastal Range and Sila Massif were the sources for the detrital constituents of the PlS Unit sandstones. The progressive uplift of Coastal Range during late Early Pleistocene and the marked backstepping of the depositional systems along the Sila footslope was accompanied by alternating phases of down-cutting and base

  18. High-resolution topography and geomorphology of select archeological sites in Glen Canyon National Recreation Area, Arizona (United States)

    Collins, Brian D.; Corbett, Skye C.; Sankey, Joel B.; Fairley, Helen C.


    Along the Colorado River corridor between Glen Canyon Dam and Lees Ferry, Arizona, located some 25 km downstream from the dam, archaeological sites dating from 8,000 years before present through the modern era are located within and on top of fluvial and alluvial terraces of the prehistorically undammed river. These terraces are known to have undergone significant erosion and retreat since emplacement of Glen Canyon Dam in 1963. Land managers and policy makers associated with managing the flow of the Colorado River are interested in understanding how the operations of Glen Canyon Dam have affected the archeological sites associated with these terraces and how dam-controlled flows currently interact with other landscape-shaping processes. In 2012, the U.S. Geological Survey initiated a research project in Glen Canyon to study the types and causes of erosion of the terraces. This report provides the first step towards this understanding by presenting comparative analyses on several types of high-resolution topographic data (airborne lidar, terrestrial lidar, and airborne photogrammetry) that can be used in the future to document and analyze changes to terrace-based archaeological sites. Herein, we present topographic and geomorphologic data of four archaeological sites within a 14 km segment of Glen Canyon using each of the three data sources. In addition to comparing each method’s suitability for adequately representing the topography of the sites, we also analyze the data within each site’s context and describe the geomorphological processes responsible for erosion. Our results show that each method has its own strengths and weaknesses, and that terrestrial and airborne lidar are essentially interchangeable for many important topographic characterization and monitoring purposes. However, whereas terrestrial lidar provides enhanced capacity for feature recognition and gully morphology delineation, airborne methods (whether by way of laser or optical sensors) are

  19. Interaction of mantle dynamics, crustal tectonics, and surface processes in the topography of the Romanian Carpathians: A geomorphological approach (United States)

    Molin, P.; Fubelli, G.; Nocentini, M.; Sperini, S.; Ignat, P.; Grecu, F.; Dramis, F.


    Tectonic processes and dynamic mantle flow impart a unique imprint on topography and geomorphic responses over time scales of 104 to 106 yr. First-order topographic features in a tectonically active landscape represent ways to quantitatively characterise the interaction between crustal tectonics, mantle dynamics, and geomorphology, providing a basis for modelling landscape evolution. We analysed the topographic features of the Romanian Carpathians, a mountain range characterised by two straight segments connected by a narrow curvature zone. The deformation started in the Late Jurassic and includes two collisional phases during the Cretaceous and Miocene. We examined the tectonic geomorphology of the Romanian Carpathians focusing on regional and local topographic setting, drainage pattern, and river long profiles. Our main database is composed of DEM-based topographic analysis, supplemented with field investigations in the Slănic River basin, located in the Carpathian curvature zone. The longitudinal profiles of rivers draining the southern Carpathians are close to the equilibrium shape, in agreement with the older emersion of the chain. The longitudinal profiles of the rivers draining the eastern and southeastern Carpathians are in a transient state of disequilibrium as a consequence of a more recent emersion of the chain and of the Pliocene-Pleistocene tectonic activity in the Bend Zone. Filtering the topography at different wavelengths, we observe a relative depression in correspondence with the Carpathian Bend, where mantle seismicity and a high-velocity zone in tomography data are located and commonly interpreted as related to an almost inactive and dying subduction zone. Contrastingly, the filtered topography presents a high in the Transylvanian basin, where tomography data show a low-velocity area, interpreted as upwelling of hot asthenospheric materials. We hypothesise that local mantle convection generates positive and negative dynamic topographies. In the

  20. The Crati River Basin: geomorphological and stratigraphical data for the Plio-Quaternary evolution of northern Calabria, South Apennines, Italy (United States)

    Robustelli, Gaetano; Muto, Francesco


    In this paper, we present the results of an integrated geomorphological and stratigraphical study carried out in the eastern side of the Crati River valley (northern Calabria, South Italy). This area is characterized by the occurrence of three order palaeosurfaces that, along with low-sloping palaeovalleys and structural landforms, are striking features of the landscape. The relationships between morpho-tectonic and sedimentary evolution of the Crati Basin has been assessed through sandstone detrital modes, morphostratigraphy and geomorphological correlation with adjacent areas. The two main unconformity surfaces that typify the Quaternary fill were correlated to different steps of landscape evolution. The presence of both erosional and depositional palaeosurfaces has been a useful marker for reconstructing sedimentary and morphogenetic events, and hence to detect drainage network evolution and changes in source sediment area. In particular, we recognized that the study area experienced, during the late Pliocene-Early Pleistocene a period of sub-aerial landscape modelling as suggested by low-sloping palaeovalleys and related fluvial deposits (1st Order Palaeosurface). At that time, the source of the detrital constituents of the PPS Unit sandstones was mainly from the Sila Massif. The onset of Coastal Range identification and uplift (Early Pleistocene) marks a change in the geomorphic scenario with tectonic driven stream incision and valley development along the eastern side of Coastal Range, along with the occurrence of depositional and erosional landsurfaces (2nd Order Palaeosurface) at footslopes. During this period, the Coastal Range and Sila Massif were the sources for the detrital constituents of the PlS Unit sandstones. The progressive uplift of Coastal Range during late Early Pleistocene and the marked backstepping of the depositional systems along the Sila footslope was accompanied by alternating phases of down-cutting and base-level stability resulting in

  1. Geomorphological surveys and software simulations for rock fall hazard assessment: a case study in the Italian Alps (United States)

    Devoto, S.; Boccali, C.; Podda, F.


    In northern Italy, fast-moving landslides represent a significant threat to the population and human facilities. In the eastern portion of the Italian Alps, rock falls are recurrent and are often responsible for casualties or severe damage to roads and buildings. The above-cited type of landslide is frequent in mountain ranges, is characterised by strong relief energy and is triggered by earthquakes or copious rainfall, which often exceed 2000 mm yr-1. These factors cause morphological dynamics with intense slope erosion and degradation processes. This work investigates the appraisal of the rock-fall hazard related to the presence of several large unstable blocks located at the top of a limestone peak, approximately 500 m NW with respect to the Village of Cimolais. Field surveys recognised a limestone block exceeding a volume of 400 m3 and identified this block as the most hazardous for Cimolais Village because of its proximity to the rocky cliff. A first assessment of the possible transit and stop areas has been investigated through in-depth traditional activities, such as geomorphological mapping and aerial photo analysis. The output of field surveys was a detailed land use map, which provided a fundamental starting point for rock fall software analysis. The geomorphological observations were correlated with DTMs derived by regional topography and Airborne Laser Scanning (ALS) surveys to recognise possible rock fall routes. To simulate properly rock fall trajectories with a hybrid computer program, particular attention was devoted to the correct quantification of rates of input parameters, such as restitution coefficients and horizontal acceleration associated to earthquakes, which historically occur in this portion of Italy. The simulation outputs regarding the distribution of rock fall end points and kinetic energy along rock falling paths highlight the hazardous situation for Cimolais Village. Because of this reason, mitigation works have been suggested to

  2. Exploring the Geomorphology of the Amazon's Planalto with Imaging Radar: Understanding the Origins of the Modern Amazon Basin (United States)

    McDonald, K. C.; Campbell, K.; Islam, R.; Azarderakhsh, M.; Cracraft, J.


    Amazonia is Earth's most iconic center of biological diversity and endemism and, owing to its contributions to global systems ecology, is arguably Earth's most important terrestrial biome . Amazonia includes a vast landscape of mostly lowland rainforest found in Brazil, Peru, Colombia, Ecuador, Bolivia, and Venezuela. It harbors the world's highest species diversity, the largest fresh-water ecosystem in the world, and contributes substantially to shaping the Earth's atmospheric gasses and oceans and consequently its climate. Despite this global importance, we still have an incomplete understanding of how this biodiversity-rich biome developed over time. Knowing its history is crucially important for understanding how the short and long-term effects of biodiversity loss and climate change will impact the region, and the globe, in the future. Hence, we seek to understand the evolutionary and environmental-ecological history of Amazonia over the past 10 million years through a comparative approach that integrates across the disciplines of systematic biology, population biology, ecosystem structure and function, geology, Earth systems modeling and remote sensing, and paleoenvironmental history. During springtime 2013, the NASA/JPL airborne imaging radar, UAVSAR, conducted airborne studies over many regions of South America including portions of the western Amazon basin. We utilize UAVSAR imagery acquired over the Madre de Dios region of southeastern Peru in an assessment of the underlying geomorphology of the Amazon's planalto, its relationship to the current distribution of vegetation, and its relationship to geologic processes through deep time. In the late Neogene, the Amazonian lowlands comprised either a series of independent basins or a single sedimentary basin. The Amazonian planalto is variously described as either an erosional surface or a surface of deposition. We employ UAVSAR data collections to assess (1) the utility of these high quality imaging radar

  3. Geomorphological surveys and software simulations for rock fall hazard assessment: a case study in the Italian Alps

    Directory of Open Access Journals (Sweden)

    S. Devoto


    Full Text Available In northern Italy, fast-moving landslides represent a significant threat to the population and human facilities. In the eastern portion of the Italian Alps, rock falls are recurrent and are often responsible for casualties or severe damage to roads and buildings. The above-cited type of landslide is frequent in mountain ranges, is characterised by strong relief energy and is triggered by earthquakes or copious rainfall, which often exceed 2000 mm yr−1. These factors cause morphological dynamics with intense slope erosion and degradation processes. This work investigates the appraisal of the rock-fall hazard related to the presence of several large unstable blocks located at the top of a limestone peak, approximately 500 m NW with respect to the Village of Cimolais. Field surveys recognised a limestone block exceeding a volume of 400 m3 and identified this block as the most hazardous for Cimolais Village because of its proximity to the rocky cliff. A first assessment of the possible transit and stop areas has been investigated through in-depth traditional activities, such as geomorphological mapping and aerial photo analysis. The output of field surveys was a detailed land use map, which provided a fundamental starting point for rock fall software analysis. The geomorphological observations were correlated with DTMs derived by regional topography and Airborne Laser Scanning (ALS surveys to recognise possible rock fall routes. To simulate properly rock fall trajectories with a hybrid computer program, particular attention was devoted to the correct quantification of rates of input parameters, such as restitution coefficients and horizontal acceleration associated to earthquakes, which historically occur in this portion of Italy. The simulation outputs regarding the distribution of rock fall end points and kinetic energy along rock falling paths highlight the hazardous situation for Cimolais Village. Because of this reason, mitigation works have

  4. Advances in Quantitative Seismic geomorphology Research%定量地震地貌学研究进展

    Institute of Scientific and Technical Information of China (English)

    冯明友; 刘小洪; 张帆; 王兴志; 李海亮


    Quantitative Seismic Geomorphology (QSG) is a new direction in quantitatively analyze of sedimentary system and reservoir characterization,which imaged in 3-D seismic data for the purposes of understanding the history,processes,and fill architecture of a basin.Through analysis of definition and characters of the contents,methods and techniques of QSG are illustrated.such as systematic geologic research,seismic attribute,geomorphologic parameters,sedimentary elements and influences analyze.The keys of QSG are data fusion and utility of morphometric data.Advances and unique of QSG are analyzed by the applications of debris channels,alluvial channels,submarine fans,delta,et al.This subject has advantage in the depositional system quantitatively research and reservoir body volume measurements by the integration of high resolution seismic image,outcrop sedimentlogy,computer simulation and sequence stratigraphy.%定量地震地貌学以三维地震数据为基础,通过对地貌特征参数的定量分析来了解盆地历史、沉积过程和填充构架,在沉积体系定量分析和储层表征方面为一新方向.其主要研究内容包括系统地质研究、地震属性分析、地貌特征定量分析、沉积单元交汇分析和沉积体系影响因素研究等五方面,核心为多数据融合及沉积单元形态定量数据的利用.定量地震地貌学在冲积河道、三角洲、浊积水道、水下扇储层特征及结构研究方面已取得较大突破,在地层沉积定量研究、储集体规模预测方面具有较大优势和前景.

  5. Integration of rainfall/runoff and geomorphological analyses flood hazard in small catchments: case studies from the southern Apennines (Italy) (United States)

    Palumbo, Manuela; Ascione, Alessandra; Santangelo, Nicoletta; Santo, Antonio


    We present the first results of an analysis of flood hazard in ungauged mountain catchments that are associated with intensely urbanized alluvial fans. Assessment of hydrological hazard has been based on the integration of rainfall/runoff modelling of drainage basins with geomorphological analysis and mapping. Some small and steep, ungauged mountain catchments located in various areas of the southern Apennines, in southern Italy, have been chosen as test sites. In the last centuries, the selected basins have been subject to heavy and intense precipitation events, which have caused flash floods with serious damages in the correlated alluvial fan areas. Available spatial information (regional technical maps, DEMs, land use maps, geological/lithological maps, orthophotos) and an automated GIS-based procedure (ArcGis tools and ArcHydro tools) have been used to extract morphological, hydrological and hydraulic parameters. Such parameters have been used to run the HEC (Hydrologic Engineering Center of the US Army Corps of Engineers) software (GeoHMS, GeoRAS, HMS and RAS) based on rainfall-runoff models, which have allowed the hydrological and hydraulic simulations. As the floods occurred in the studied catchments have been debris flows dominated, the solid load simulation has been also performed. In order to validate the simulations, we have compared results of the modelling with the effects produced by past floods. Such effects have been quantified through estimations of both the sediment volumes within each catchment that have the potential to be mobilised (pre-event) during a sediment transfer event, and the volume of sediments delivered by the debris flows at basins' outlets (post-event). The post-event sediment volume has been quantified through post-event surveys and Lidar data. Evaluation of the pre-event sediment volumes in single catchments has been based on mapping of sediment storages that may constitute source zones of bed load transport and debris flows. For

  6. Fluvial geomorphological response along the upland sediment cascade during the record-breaking December 2015 floods, Cumbria, UK (United States)

    Russell, Andrew; Perks, Matthew; Large, Andrew; Dunning, Stuart; Warburton, Jeff


    Between 0900 GMT on 4th December and 0900 GMT on 6th December 2015, Atlantic Storm Desmond produced over 260 mm of rainfall in Cumbria, northwest England, representing a new UK 48 hour rainfall maximum, and breaking previous records set in 2005 and 2009. The December 2015 event resulted in a number of rivers significantly exceeding their 2009 levels, over-topping recently-commissioned flood defences, destroying bridges and flooding thousands of homes. Our research aim is to identify factors controlling significant geomorphological and sedimentary response during Storm Desmond along the upland sediment cascade including: Rattling Beck (Glenridding), a high gradient upland stream draining the flanks of Helvellyn (950 m.a.o.d.), and a 25km extended reach of the lower gradient piedmont Derwent River corridor downstream of Bassenthwaite Lake. Rattling Beck descends steeply from the eastern slopes of the Helvellyn massif draining across an alluvial fan into Lake Ullswater. On 5th December 2015 the village of Glenridding was severely impacted by flooding which deposited boulder-sized sediment within the centre of the village, completely blocking the pre-existing stream course and causing avulsion of waning stage flows through riverside properties. A major new sediment lobe was deposited on the existing alluvial fan downstream of the village, grading to the temporarily raised lake water level. Although a number of hillslope failures occurred in the higher catchment, the majority of the sediment transported by Rattling Beck and impacting the village was acquired within a 2km reach upstream of Glenridding through erosion of older glacial and alluvial sediments. Lateral channel erosion was enhanced by inability of flood flows to rework highly resistant boulder bar lag deposits related to a previous mine tailings dam failure in 1927. The River Derwent corridor extends for 30km downstream of Bassenthwaite Lake to the Irish Sea at Workington and has a sinuous course ranging in

  7. Geomorfología aplicada y desastres: Rol preventivo y Ordenamiento Territorial. / Applied Geomorphology and disasters: prevention and Land Management Role.

    Directory of Open Access Journals (Sweden)

    Ferrando A., Francisco J.


    Full Text Available El desarrollo sostenible de un país altamente expuesto a catástrofes de origen natural dependerá en gran medida, de la manera en que se ordene el territorio, considerando su base geográfica. En este contexto, la geomorfología debe ir más allá del academicismo y aportar al ordenamiento territorial./"Applied Geomorphology and Disasters: Preventive Roles and Territorial Planning". The sustainable development of a country which is prone to suffer natural catastrophes will depend greatly on the manner in which its territory is planned, taking into consideration its geography. Thus, geomorphology must go beyond the academic practice and contribute to Landscape and Territorial Planning.

  8. Geomorphological Inventory as a Tool for Proclaiming Geomorphosite (a Case Study of Mt. Myslivna in the Novohradské hory Mts. — Czech Republic)


    Rypl, J.; Kirchner, K. (Karel); Dvořáčková, S.


    The study locality of Mt. Myslivna within the Novohradské hory Mts. (the Czech Republic) represents an area with restricted access prior to 1989. Detailed geomorphological inventory carried out in years 2002 – 2010. Destructive as well as accumulative rock landforms were mapped with the use of GPS. The northwestern slopes of Mt. Myslivna were declared a Natural Monument due to its natural beech wood vegetation in 1992. However, the extent of the protected area does not include qualitatively a...

  9. Chronostratigraphy and geomorphology of washover fans in the Exmouth Gulf (NW Australia) - A record of tropical cyclone activity during the late Holocene (United States)

    May, Simon Matthias; Brill, Dominik; Leopold, Matthias; Callow, John Nikolaus; Engel, Max; Scheffers, Anja; Opitz, Stephan; Norpoth, Maike; Brückner, Helmut


    Washover fans typically form due to barrier overwash or breaching and coastal inundation and generally represent geomorphological and depositional evidence of intense storms. Few studies have investigated the chronostratigraphy of washover fans in order to infer magnitude/frequency patterns of extreme-wave events over longer time scales. Here we present new data on the chronostratigraphy of late Holocene washover fans in the Exmouth Gulf (Western Australia) by using ground penetrating radar and unmanned aerial vehicle (UAV) survey techniques, as well as geomorphological, sedimentological and chronological investigations. This study aims to (i) provide a detailed characterization of the washover fans' geomorphology and stratigraphical architecture; (ii) document depositional processes involved in their formation; (iii) establish a chronostratigraphy based on optically stimulated luminescence (OSL); and (iv) understand the significance of the washover fans for recording past tropical cyclone (TC) activity. The fans consist of multiple sequences of sand, shell debris and coral rubble comprising depositional units related to TC-induced inundation. The units are separated by palaeosurfaces with incipient soil formation, formed during periods of reduced depositional activity. In combination with the interpretation of a UAV-based high-resolution digital surface model, multiple phases of reactivation are inferred. OSL results allow the establishment of a local long-term TC record and suggest storm-induced deposition at ∼170, ∼360, ∼850 and ∼1300 years ago. Further units were dated to ∼1950, ∼2300, and ∼2850 years ago. The chronology of TC events is consistent with other work relating TC activity with El Niño Southern Oscillation (ENSO) and sea surface temperature (SST) patterns, corroborating the regional palaeotempestological relevance of this unique geomorphological record.

  10. Trends in publications in fluvial geomorphology over two decades: A truly new era in the discipline owing to recent technological revolution? (United States)

    Piégay, Hervé; Mathias Kondolf, G.; Toby Minear, J.; Vaudor, Lise


    Trends in the field of fluvial geomorphology have been reviewed by a number of authors, who have emphasized the dramatic change occuring in the field in the last two decades of the twentieth century, largely as a result of technological advances. Nevertheless, no prior authors have systematically compiled data on publications in fluvial geomorphology over a long period and statistically analyzed the resulting data set. In this contribution we present a quantitative analysis of fluvial geomorphology papers published in the twenty-two-year period 1987-2009 in five journals of the discipline with a more specific focus on Geomorphology and Earth Surface Processes and Landforms (ESPL), identifying authorships, geographic origin of authors, and spatial and temporal scales covered. We also documented the tools employed, demonstrating the transformation of the field with the emergence of new tools over this period, and conducted a cluster to highlight links between tools and a set of factors (country of author's origin, journals, time, and spatial and temporal scales). Of the 1717 papers published in the five journals during this period, the results showed an increased diversity in the nationality of the first author, mainly when dealing with present time scale, and channel feature. Our data show a significant change in methods used in the field as a result of the increase in data availability and new sources of information from remote sensing (ground, airborne and, satellite). Clearly, a new era in knowledge production is observed since 2000, showing the emergence of a second period of active quantification and an internationalization of the fields.

  11. Geomorphological mapping of glacial landforms from remotely sensed data: An evaluation of the principal data sources and an assessment of their quality (United States)

    Smith, M. J.; Rose, J.; Booth, S.


    This paper presents the results of an experiment to compare glacial geomorphology mapped from remotely sensed imagery with 1 : 10,000-scale field mapping. The field mapping was validated against high resolution LiDAR imagery of an area glacierized during the Younger Dryas and found to provide an essentially reliable, if not complete, representation of the glacial geomorphology. The experiment consists of comparing the field mapping with digital elevation models (Shuttle Radar Topography Mission C-Band, Landmap, OS Panorama®, OS Profile®, NEXTMap) and satellite imagery (Landsat Thematic Mapper) of a 100-km 2 region of central Scotland, north of Glasgow, that was last glaciated during the Last Glacial Maximum and during the Younger Dryas, respectively c. 14.5 and 11.5 cal. ka BP. For the purposes of this exercise, we concentrated on glacial lineaments (flutes, drumlins, and crag and tail), but attention was also given to moraine ridges and eskers. Qualitative and quantitative comparisons are performed and the results show that of the remotely sensed data sets, only NEXTMap Great Britain™ provided results that showed any approximation to the field mapping. OS Panorama® and OS Profile® provided very poor approximations, and the other methods fail to provide any information of value. Attention is given to the issues of scale and the differences between a small-scale detailed study, such as this experiment, in which a high resolution glacial geomorphological reconstruction is required, and the small-scale studies where the remote sensing techniques used here provide important evidence of regional significance when glaciers formed the largest elements of the landscape. The paper concludes with a consideration of protocols for future geomorphological mapping exercises, and outlines some of the requirements that must be adopted as these protocols are developed.

  12. Trends in publications in fluvial geomorphology over two decades: A truly new era in the discipline owing to recent technological revolution? (United States)

    Piégay, Hervé; Kondolf, G. Mathias; Minear, J. Toby; Vaudor, Lise


    Trends in the field of fluvial geomorphology have been reviewed by a number of authors, who have emphasized the dramatic change occuring in the field in the last two decades of the twentieth century, largely as a result of technological advances. Nevertheless, no prior authors have systematically compiled data on publications in fluvial geomorphology over a long period and statistically analyzed the resulting data set. In this contribution we present a quantitative analysis of fluvial geomorphology papers published in the twenty-two-year period 1987–2009 in five journals of the discipline with a more specific focus on Geomorphology and Earth Surface Processes and Landforms (ESPL), identifying authorships, geographic origin of authors, and spatial and temporal scales covered. We also documented the tools employed, demonstrating the transformation of the field with the emergence of new tools over this period, and conducted a cluster to highlight links between tools and a set of factors (country of author's origin, journals, time, and spatial and temporal scales). Of the 1717 papers published in the five journals during this period, the results showed an increased diversity in the nationality of the first author, mainly when dealing with present time scale, and channel feature. Our data show a significant change in methods used in the field as a result of the increase in data availability and new sources of information from remote sensing (ground, airborne and, satellite). Clearly, a new era in knowledge production is observed since 2000, showing the emergence of a second period of active quantification and an internationalization of the fields.

  13. GIS- and field based mapping of geomorphological changes in a glacier retreat area: A case study from the Kromer valley, Silvretta Alps (Austria) (United States)

    Guttmann, Markus; Pöppl, Ronald


    Global warming results in an ongoing retreat of Alpine glaciers, leaving behind large amounts of easily erodible sediments. As a consequence processes like rockfalls, landslides and debris flows as well as fluvial processes occur more frequently in pro- and paraglacial areas, often involving catastrophic consequences for humans and infrastructure in the affected valleys. The main objective of the presented work was to map and spatially quantify glacier retreat and geomorphological changes in the Kromer valley, Silvretta Alps (Austria) by applying GIS- and field-based geomorphological mapping. In total six geomorphological maps (1950s, 1970s, 2001, 2006, 2012, and 2016) were produced and analyzed in the light of the study aim. First results have shown a significant decrease of total glaciated area from 96 ha to 53 ha which was accompanied by increased proglacial geomorphic activity (i.e. fluvial processes, rockfalls, debris flows, shallow landslides) in the last 15 years. More detailed results will be presented at the EGU General Assembly 2017.

  14. Tree species diversity and its relationship to stand parameters and geomorphology features in the eastern Black Sea region forests of Turkey. (United States)

    Ozcelik, Ramazan; Gul, Altay Ugur; Merganic, Jan; Merganicova, Katarina


    We studied the effects of stand parameters (crown closure, basal area, stand volume, age, mean stand diameter number of trees, and heterogeneity index) and geomorphology features (elevation, aspect and slope) on tree species diversity in an example of untreated natural mixed forest stands in the eastern Black Sea region of Turkey. Tree species diversity and basal area heterogeneity in forest ecosystems are quantified using the Shannon-Weaver and Simpson indices. The relationship between tree species diversity basal area heterogeneity stand parameters and geomorphology features are examined using regression analysis. Our work revealed that the relationship between tree species diversity and stand parameters is loose with a correlation coefficient between 0.02 and 0.70. The correlation of basal area heterogeneity with stand parameters fluctuated between 0.004 and 0.77 (R2). According to our results, stands with higher tree species diversity are characterised by higher mean stand diameter number of diameter classes, basal area and lower homogeneity index value. Considering the effect of geomorphology features on tree species or basal area heterogeneity we found that all investigated relationships are loose with R tree species diversity and aspect. Future work is required to verify the detected trends in behaviour of tree species diversity if it is to estimate from the usual forest stand parameters and topography characteristics.

  15. The geomorphology of Patagonian ice dammed lake basins: Insights from remote sensing of a modern lake and reconstruction of a Late Quaternary lake drainage event (United States)

    Thorndycraft, Varyl


    The geomorphology of ice dammed lake basins can be complex due to geomorphic responses to multiple base level changes from repeated filling and emptying, as well as the potential for catastrophic drainage events. Refining landscape models of Quaternary ice dammed palaeolake systems has the potential to improve our understanding of glacier and meltwater dynamics during deglaciation phases. In this poster two case studies are presented to shed light on the range of geomorphic processes exhibited within ice dammed lake basins. Using Google Earth Pro and repeat LANDSAT imagery the geomorphology resulting from multiple base level changes of an ice dammed lake of the Viedma Glacier (Southern Patagonia Icefield) is presented. The LANDSAT imagery shows transgressive lake phases inundating already formed delta and terrace surfaces, whilst the high resolution Google Earth Pro images reveal a complex suite of incised terrace levels developed on the valley floor following lake drainage events. Secondly, the impact of catastrophic drainage of the Late Pleistocene Palaeolake Cochrane (Northern Patagonia Icefield) is investigated through geomorphological mapping. Here an outburst flood and rapid lowering of the lake has led to large scale eddy scouring of glacio-lacustrine sediments, with scarp slopes of ca. 30-40 m in height, and the formation of boulder bars during the final stages of lake fall. The implications of the mapping for interpretations of Late Quaternary palaeolake sediment-landform assemblages and rates of landscape change are discussed.

  16. The mystery of Bunge Land (New Siberian Archipelago): implications for its formation based on palaeoenvironmental records, geomorphology, and remote sensing (United States)

    Schirrmeister, Lutz; Grosse, Guido; Kunitsky, Viktor V.; Fuchs, Margret C.; Krbetschek, Matthias; Andreev, Andrei A.; Herzschuh, Ulrike; Babyi, Olga; Siegert, Christine; Meyer, Hanno; Derevyagin, Alexander Y.; Wetterich, Sebastian


    Multiproxy datasets (geocryology, geochronology, sedimentology, palaeo-ecology) from permafrost exposures were used together with land surface information based on satellite imagery and thematic maps in order to reconstruct the Lateglacial to Holocene landscape and environmental dynamics of Bunge Land (Zemlya Bunge). This area of little relief, situated in the New Siberian Archipelago, connects the geomorphologically well-structured islands of Kotel'ny and Fadeevsky. A buried thermokarst landscape was found in the northwest region of the Bunge Land low terrace sand plain, whereas the Bunge Land high terrace seems to be an exposed residue of a similar late Quaternary thermokarst landscape. That is confirmed especially by radiocarbon accelerator mass spectrometry and optically stimulated luminescence age determinations, and by pollen analyses. Palaeogeographically, the late Pleistocene periglacial landscape and sedimentation of Bunge Land was closely connected to Kotel'ny and Fadeevsky; only later on seismotectonical block movements resulted in reshaping parts of Bunge Land. The Bunge Land low terrace area first subsided and the original landscape there was destroyed by marine inundation, followed by marine sedimentation. Subsequent block heave of the low terrace region exposed a vast sheet of marine sands which is continuously surficially reworked by aeolian processes, while the original alluvial plain landscape in the high terrace area was preserved and started degrading only by early Holocene thermokarst development. The studied exposures contain one of the northernmost (74.88°N) environmental records for the late Pleistocene-Holocene transition in the Eurasian Arctic.

  17. Incorporating geology and geomorphology in land management decisions in developing countries: A case study in Southern Costa Rica (United States)

    Andreas, Mende; Allan, Astorga


    The fast and uncontrolled expansion of industries, agriculture and settlements in developing countries implies a definite need to develop strategies for effective land management. For this reason we carried out a case study in southern Costa Rica within an area of high vulnerability for landslides and seismic hazards aiming at the development of a GIS-based system for the analysis of the physical environment that is of practical use for land management decisions in developing regions with limited financial, technical and data resources. Our concept is based upon the assessment of five so-called geofactors, reflecting the most important aspects for land management planning: (1) Lithology/Petrophysics, (2) Geomorphology, (3) Hydrogeology, (4) Slope Stability and (5) Seismic Hazards. In order to take as much advantage as possible of the limited existing base data, and efficient tools for data collection, evaluation of data quality and data analysis were developed. Second-degree normalization of all database attributes guarantees extensive data query and access possibilities. The application of geofactor terrain analysis for land management is discussed on the basis of a land use plan for the town of Rio Claro located in the NE of the study area.

  18. Hydrological and geomorphological controls on a mangrove forest maintenance during the dry season in the Pacific Coast of Nicaragua (United States)

    Calderon, Heyddy; Weeda, Ruben; Uhlenbrook, Stefan


    Hydrological and geomorphological processes are key to mangrove forest growth and development. However, very few studies have been carried out in Central American mangroves to understand their hydrological functioning. Here, a small mangrove forest (0.2 km2) in the South Pacific coast of Nicaragua was investigated to determine sources of freshwater inputs and fluxes of water and nutrients to the sea during the dry season. The general groundwater flow direction is from NE to SW towards the sea. The aquifer is composed of clay and alluvial deposits overlying a fractured shale unit. Shallow groundwater is influenced by a nearby town through infiltration of grey water and pit latrines. Groundwater from the mangrove showed Mn2+ and Fe2+ presence indicating occurrence of denitrification and the role of the mangrove as a nutrient sink. Also, refreshening and salinization processes were identified near the river, indicated by different water facies. Freshwater inputs from precipitation and groundwater discharge maintain adequate salt gradients. The water balance showed an increase of around 619 m3 d-1 in storage during a 22 study period during the dry season, which is reflected by increased hydraulic heads and river stage. Water storage is fostered by low conductivity soil materials and beach ridges parallel to the coast line, whereby the latter occassionally breach due to overtopping of surface water. These conditions favor forest subsistence during the dry season, allowing the mangrove to continue to provide ecological and economic benefits in terms of protection against flooding, habitat for numerous species and tourist attraction.

  19. Geomorphological Analysis and Hydrological Potential Zone of Baira River Watershed, Churah in Chamba District of Himachal Pradesh, India

    Directory of Open Access Journals (Sweden)

    Kuldeep Pareta


    Full Text Available In the present study, an attempt has been made to study the quantitative geomorphological analysis and hydrological characterization of 95 micro-watersheds (MWS of Baira river watershed in Himachal Pradesh, India with an area of 425.25 Km2. First time in the world, total 173 morphometric parameters have been generated in a single watershed using satellite remote sensing data (i.e. IRS-P6 ResourceSAT-1 LISS-III, LandSAT-7 ETM+, and LandSAT-8 PAN & OLI merge data, digital elevation models (i.e. IRS-P5 CartoSAT-1 DEM, ASTER DEM data, and soI topographical maps of 1: 50,000 scale. The ninety-five micro-watersheds (MWS of Baira river watershed have been prioritized through the morphometric analysis of different morphometric parameters (i.e. drainage network, basin geometry, drainage texture analysis, and relief characterizes . The study has concurrently established the importance of geomorphometry as well as the utility of remote sensing and GIS technology for hydrological characterization of the watershed and there for better resource and environmental managements.

  20. Geomorphologic, stratigraphic and sedimentologic evidences of tectonic activity in Sone–Ganga alluvial tract in Middle Ganga Plain, India

    Indian Academy of Sciences (India)

    Sudarsan Sahu; Dipankar Saha


    The basement of the Ganga basin in the Himalayan foreland is criss-crossed by several faults, dividing the basin into several sub-blocks forming horsts, grabens, or half-grabens. Tectonic perturbations along basement faults have affected the fluvial regime and extent of sediment fill in different parts of the basin during Late Quaternary. The East Patna Fault (EPF) and the West Patna Fault (WPF), located in Sone–Ganga alluvial tract in the southern marginal parts of Middle Ganga Plain (MGP), have remained tectonically active. The EPF particularly has acted significantly and influenced in evolving the geomorphological landscape and the stratigraphic architecture of the area. The block bounded by the two faults has earlier been considered as a single entity, constituting a half-graben. The present investigation (by morpho-stratigraphic and sedimentologic means) has revealed the existence of yet another fault within the half-graben, referred to as Bishunpur–Khagaul Fault (BKF). Many of the long profile morphological characters (e.g., knick-zone, low width–depth ratio) of the Sone River at its lower reaches can be ascribed to local structural deformation along BKF. These basement faults in MGP lie parallel to each other in NE–SW direction.

  1. Structural features of the southern Tulum Fault System, western central Argentina, through gravimetric data and geomorphologic analyses (United States)

    Rodríguez, Aixa I.; Christiansen, Rodolfo O.; Suvires, Graciela M.; Lince Klinger, Federico; Martinez, M. Patricia


    A gravimetric analysis over the Tulum Valley was made. This data was used to reveal the structural setting of the Tulum Fault System situated in the southeastern part of San Juan province in the arid western part of Argentina. This system is the boundary between two geological provinces, the eastern Precordillera Oriental and the Sierras Pampeanas Occidentales. Gravity data was processed using upward continuation and vertical derivative filters and all the results were compared with the geomorphological and the drainage systems maps of the area. Our assessment confirms the presence of two structures in the Pampeano basement with positive anomalies similar to those found in Valdivia and Barboza hills, two important depocenters with low gravimetric gradients separated by a zone with higher gravity anomalies than the depocenters to the east and west. In view of this, a structural map is proposed for the area. This system is important not only because it is the boundary between two geological provinces and has significance regarding regional tectonic issues but also because it controls the surface drainage, soils distribution and groundwater flow of the Tulum basin conditioning the land use distribution.

  2. Detailed sedimentology and geomorphology elucidate mechanisms of formation of modern and historical sequences of minor moraines in the European Alps (United States)

    Wyshnytzky, Cianna; Lukas, Sven


    Suites of closely-spaced minor moraines may help further understanding of glacier retreat and predict its geomorphological effects through the observations of moraine formation on short timescales. This research is common in lowland, maritime settings (Sharp, 1984; Boulton, 1986; Krüger, 1995; Reinardy et al., 2013), but remains sparse in high-mountain settings (Hewitt, 1967; Ono, 1985; Beedle et al., 2009; Lukas, 2012). This research presents detailed sedimentological and geomorphological research on minor moraines at two high-mountain settings in the Alps: Silvrettagletscher, Switzerland, as a modern setting and Schwarzensteinkees, Austria, as a historical setting. Geomorphological investigations included mapping and measurements through field observations and assessing aerial imagery. Additionally, terrestrial laser scanning and ground-penetrating radar data were collected in the Schwarzensteinkees foreland. Detailed sedimentological investigations followed excavation of seven moraines at Silvrettagletscher and five moraines at Schwarzensteinkees and include multiple scales of observation and measurements to support interpretations of sediment transport and deposition (e.g. Evans and Benn, 2004). The modern moraines at Silvrettagletscher, in the immediately proglacial foreland, have been forming since before 2003. Four mechanisms of formation show distinct sedimentological signatures: formerly ice-cored moraines (e.g. Kjær & Krüger, 2001; Lukas, 2012; Reinardy et al., 2013) , push moraine formation on a reverse bedrock slope (e.g. Lukas, 2012), push moraine formation incorporating sediments deposited in a former proglacial basin, and basal freeze-on (e.g. Andersen & Sollid, 1971; Krüger, 1995; Reinardy et al., 2013). Schwarzensteinkees still exists but is currently restricted to steeply-dipping bedrock slabs above the main valley. This study therefore investigates the moraines in the foreland that formed between approximately 1850 and 1930. The minor

  3. Geomorphology and late Holocene accretion history of Adele Reef: a northwest Australian mid-shelf platform reef (United States)

    Solihuddin, Tubagus; Bufarale, Giada; Blakeway, David; O'Leary, Michael J.


    The mid-shelf reefs of the Kimberley Bioregion are one of Australia's more remote tropical reef provinces and such have received little attention from reef researchers. This study describes the geomorphology and late Holocene accretion history of Adele Reef, a mid-shelf platform reef, through remote sensing of contemporary reef habitats, shallow seismic profiling, shallow percussion coring and radiocarbon dating. Seismic profiling indicates that the Holocene reef sequence is 25 to 35 m thick and overlies at least three earlier stages of reef build-up, interpreted as deposited during marine isotope stages 5, 7 and 9 respectively. The cored shallow subsurface facies of Adele Reef are predominantly detrital, comprising small coral colonies and fragments in a sandy matrix. Reef cores indicate a `catch-up' growth pattern, with the reef flat being approximately 5-10 m deep when sea level stabilised at its present elevation 6,500 years BP. The reef flat is rimmed by a broad low-relief reef crest only 10-20 cm high, characterised by anastomosing ridges of rhodoliths and coralliths. The depth of the Holocene/last interglacial contact (25-30 m) suggests a subsidence rate of 0.2 mm/year for Adele Reef since the last interglacial. This value, incorporated with subsidence rates from Cockatoo Island (inshore) and Scott Reefs (offshore), provides the first quantitative estimate of hinge subsidence for the Kimberley coast and adjacent shelf, with progressively greater subsidence across the shelf.

  4. Geomorphological activity at a rock glacier front detected with a 3D density-based clustering algorithm (United States)

    Micheletti, Natan; Tonini, Marj; Lane, Stuart N.


    Acquisition of high density point clouds using terrestrial laser scanners (TLSs) has become commonplace in geomorphic science. The derived point clouds are often interpolated onto regular grids and the grids compared to detect change (i.e. erosion and deposition/advancement movements). This procedure is necessary for some applications (e.g. digital terrain analysis), but it inevitably leads to a certain loss of potentially valuable information contained within the point clouds. In the present study, an alternative methodology for geomorphological analysis and feature detection from point clouds is proposed. It rests on the use of the Density-Based Spatial Clustering of Applications with Noise (DBSCAN), applied to TLS data for a rock glacier front slope in the Swiss Alps. The proposed methods allowed the detection and isolation of movements directly from point clouds which yield to accuracies in the following computation of volumes that depend only on the actual registered distance between points. We demonstrated that these values are more conservative than volumes computed with the traditional DEM comparison. The results are illustrated for the summer of 2015, a season of enhanced geomorphic activity associated with exceptionally high temperatures.

  5. Geomorphology and late Holocene accretion history of Adele Reef: a northwest Australian mid-shelf platform reef (United States)

    Solihuddin, Tubagus; Bufarale, Giada; Blakeway, David; O'Leary, Michael J.


    The mid-shelf reefs of the Kimberley Bioregion are one of Australia's more remote tropical reef provinces and such have received little attention from reef researchers. This study describes the geomorphology and late Holocene accretion history of Adele Reef, a mid-shelf platform reef, through remote sensing of contemporary reef habitats, shallow seismic profiling, shallow percussion coring and radiocarbon dating. Seismic profiling indicates that the Holocene reef sequence is 25 to 35 m thick and overlies at least three earlier stages of reef build-up, interpreted as deposited during marine isotope stages 5, 7 and 9 respectively. The cored shallow subsurface facies of Adele Reef are predominantly detrital, comprising small coral colonies and fragments in a sandy matrix. Reef cores indicate a `catch-up' growth pattern, with the reef flat being approximately 5-10 m deep when sea level stabilised at its present elevation 6,500 years BP. The reef flat is rimmed by a broad low-relief reef crest only 10-20 cm high, characterised by anastomosing ridges of rhodoliths and coralliths. The depth of the Holocene/last interglacial contact (25-30 m) suggests a subsidence rate of 0.2 mm/year for Adele Reef since the last interglacial. This value, incorporated with subsidence rates from Cockatoo Island (inshore) and Scott Reefs (offshore), provides the first quantitative estimate of hinge subsidence for the Kimberley coast and adjacent shelf, with progressively greater subsidence across the shelf.

  6. Integration of the geomorphological environment and cultural heritage for tourism promotion: a case study from Gozo (Maltese Islands) (United States)

    Coratza, Paola; Gauci, Ritienne; Schembri, John A.; Soldati, Mauro; Tonelli, Chiara


    The paper aims to highlight the unique integration of natural and cultural heritage within the Dwejra area, a site of outstanding scenery located along the NW coast of the Island of Gozo (Malta). Dwejra displays a great variety of geological and geomorphological features as well as unusual and unique ecological systems, concentrated in a relatively small and remoteness area. The landscape is made of a large set of landforms created by several processes: karst dissolution, forming at least four solution subsidence structures in the area; fluvial processes (marked by the presence of perennial freshwater pools), seepage from cliffs, waterfall and several dry valley systems (widien); marine erosion processes as evidenced by the great variety of features, including with sea-caves, tunnel, arches, stacks and reefs. The presence of cultural features spanning from rubble walls and rural structures, to cart-ruts of unknown age and structures of the 19th Century enrich the interest in the area and allow it to become a landmark of cultural importance to the history of the island as a whole. This unique combination of geological l.s., cultural and biological heritage contributes in making Dwejra a site of extraordinary scientific importance and heritage value, an ideal tourist destination for fostering a varied form of geotourism. In perspective of tourism promotion and geoconservation measures, this paper aims at highlighting how the integration of environmental and cultural heritage aspects makes the Dwejra area a site of remarkable value to be promoted for a more holistic and varied tourism.

  7. Fluvial geomorphology and aquatic-to-terrestrial Hg export are weakly coupled in small urban streams of Columbus, Ohio (United States)

    Sullivan, S. Mažeika P.; Boaz, Lindsey E.; Hossler, Katie


    Although mercury (Hg) contamination is common in stream ecosystems, mechanisms governing bioavailability and bioaccumulation in fluvial systems remain poorly resolved as compared to lentic systems. In particular, streams in urbanized catchments are subject to fluvial geomorphic alterations that may contribute to Hg distribution, bioaccumulation, and export across the aquatic-to-terrestrial boundary. In 12 streams of urban Columbus, Ohio, we investigated the influence of fluvial geomorphic characteristics related to channel geometry, streamflow, and sediment size and distribution on (1) Hg concentrations in sediment and body burdens in benthic larval and adult emergent aquatic insects and (2) aquatic-to-terrestrial contaminant transfer to common riparian spiders of the families Pisauridae and Tetragnathidae via changes in aquatic insect Hg body burdens as well as in aquatic insect density and community composition. Hydrogeomorphic characteristics were weakly related to Hg body burdens in emergent insects (channel geometry) and tetragnathid spiders (streamflow), but not to Hg concentrations in sediment or benthic insects. Streamflow characteristics were also related to emergent insect density, while wider channels were associated with benthic insect community shifts toward smaller-bodied and more tolerant taxa (e.g., Chironomidae). Thus, our results provide initial evidence that fluvial geomorphology may influence aquatic-to-terrestrial contaminant Hg transfer through the collective effects on emergent insect body burdens as well as on aquatic insect community composition and abundance.

  8. Methods for acquiring data on terrain geomorphology, course geometry and kinematics of competitors' runs in alpine skiing: a historical review. (United States)

    Erdmann, Włodzimierz S; Giovanis, Vassilis; Aschenbrenner, Piotr; Kiriakis, Vaios; Suchanowski, Andrzej


    This paper aims at the description and comparison of methods of topographic analysis of racing courses at all disciplines of alpine skiing sports for the purposes of obtaining: terrain geomorphology (snowless and with snow), course geometry, and competitors' runs. The review presents specific methods and instruments according to the order of their historical appearance as follows: (1) azimuth method with the use of a compass, tape and goniometer instruments; (2) optical method with geodetic theodolite, laser and photocells; (3) triangulation method with the aid of a tape and goniometer; (4) image method with the use of video cameras; (5) differential global positioning system and carrier phase global positioning system methods. Described methods were used at homologation procedure, at training sessions, during competitions of local level and during International Ski Federation World Championships or World Cups. Some methods were used together. In order to provide detailed data on course setting and skiers' running it is recommended to analyse course geometry and kinematics data of competitors' running for all important competitions.

  9. Geomorphological evidences of post-LGM glacial advancements in the Himalaya: A study from Chorabari Glacier, Garhwal Himalaya, India

    Indian Academy of Sciences (India)

    Manish Mehta; Zahid Majeed; D P Dobhal; Pradeep Srivastava


    Field geomorphology and remote sensing data, supported by Optical Stimulated Luminescence (OSL) dating from the Mandakini river valley of the Garhwal Himalaya enabled identification of four major glacial events; Rambara Glacial Stage (RGS) (13 ± 2 ka), Ghindurpani Glacial Stage (GhGS) (9 ± 1 ka), Garuriya Glacial Stage (GGS) (7 ± 1 ka) and Kedarnath Glacial Stage (KGS) (5 ± 1 ka). RGS was the most extensive glaciation extending for ∼6 km down the valley from the present day snout and lowered to an altitude of 2800 m asl at Rambara covering around ∼31 km2 area of the Mandakini river valley. Compared to this, the other three glaciations (viz., GhGS, GGS and KGS) were of lower magnitudes terminating around ∼3000, ∼3300 and ∼3500 m asl, respectively. It was also observed that the mean equilibrium line altitude (ELA) during RGS was lowered to 4747 m asl compared to the present level of 5120 m asl. This implies an ELA depression of ∼373 m during the RGS which would correspond to a lowering of ∼2°C summer temperature during the RGS. The results are comparable to that of the adjacent western and central Himalaya implying a common forcing factor that we attribute to the insolation-driven monsoon precipitation in the western and central Himalaya.


    Institute of Scientific and Technical Information of China (English)

    J.Berking; A.Keil; B.Schütt


    The endorheic Lake Nam Co,south Eastern Tibetan Plateau,was selected to investigate the interrelation between drainage basin processes,especially post-glacial glacier decay,and lake level fluctuations.Landforms of the drainage basin are highly influenced by tectonics,superimposed by fluvial and periglacial processes,and locally by glacial and eolian processes.Thus,geomorphological features and hydrological characteristics were compiled for the lake-basin to provide an overview of the landscape character.Data show that during the Last Glacial Maximum melt water from the mountains accumulated fluvial deposits in the foreland.Concurrently,an increase of the lake level occurred which is presently shown by a cliff line all around Nam Co with its base approximately 29m above the present lake level.The Holocene decrease of the lake level is traced by beach ridges.As Nam Co is an endorheic lake post-glacial water loss has to be primarily explained by evaporation and moisture conditions.However,more detailed conclusions on quantitative and chronological patterns of both factors,melt-water input and evaporation output,still remain to be drawn.

  11. Modern geomorphological environment research during rapid urbanization in Shenzhen east coastal zone%快速城市化过程中的深圳东部海岸地貌环境与可持续发展

    Institute of Scientific and Technical Information of China (English)

    郭伟; 李书恒; 朱大奎


    The geomorphological environment is one of the most fundamental variables affecting the development of human society. The mission of geomorphological environment research is to explore the most basic environment and features of our Earth's surface morphology. The results can be applied to resource evaluation, environmental protection and reducing and preventing geological disasters. Thus, it can serve to help achieve sustainable development. This paper examines the Shenzhen east coastal zone as a case strongly influenced by urban expansion. We use modern geomorphological theory and methods, along with GIS and RS techniques, to reveal key characteristics of the geomorphological environment and landform classification. Furthermore, coastal ecosystem evaluation and regional resources sustainable utilization should be considered relative to the corresponding geomorphological environment. Based on this study, we conclude that modern geomorphological theory and methods, supported by "3S" techniques including GIS, RS and GPS, can play an important role in resolving the environment, resources and population problems as well as sustainable development challenges facing humankind at present.

  12. Network analysis of sediment cascades derived from a digital geomorphological map - an example from the Gradenbach catchment (Schober Mountains, Austrian Alps) (United States)

    Götz, Joachim; Heckmann, Tobias; Schrott, Lothar


    A detailed geomorphological map of the Gradenbach catchment (32 km², Schober Mountains, Austrian Alps) is presented that focuses on the sediment transfer system. Data were acquired in the field and by the interpretation of orthophotos, LIDAR data and derivatives (slope, curvature, aspect, shaded relief). The resulting digital geomorphological map contains polygon representations of landforms together with their morphometric parameters and an assessment of recent geomorphic activity. Special attention was paid to landform coupling, i.e. an additional table was constructed that indicates recently observable coupling between specific landforms (based on their ID in the database). From these data, we can obtain sediment cascades as a succession of coupled landforms along which sediment transfer occurs through the activity of various geomorphic processes. Based on this digital landform inventory the sediment transfer system is analysed using graph theory. As a rather new approach in geomorphology (already established within several disciplines; e.g. hydrology, biogeography), graph theory provides a promising framework for connectivity analysis in geomorphologic systems and powerful tools to visualise and analyse catchment-wide sediment transfer networks. Since the concept is arbitrarily scalable it can be applied to discrete land surface units (e.g. mapped landforms) or to continuous surface data (e.g. grid cells). In combination with geomorphological mapping, the concept allows for the (abstracted) visualisation of complex coupling relationships between multiple sediment storage landforms. Graph networks can be analysed at the level of nodes (e.g. the number of incoming and/or outgoing edges and their character as sediment source, sink or link), edges (e.g. importance within the network as conveyors of sediment from different sources), pathways (e.g. edge sequences leading to the catchment outlet or to storage landforms; these can be termed sediment cascades), or the

  13. Investigation on the geomorphological characteristics of the Kabutar Ali Chai watershed (NW Iran) and their role in flood production (United States)

    Jananeh, Keristineh


    The Kabutar Ali Chai watershed is located in NW Iran, 75 km northwest of Tabriz, on the southern hillsides of Mishow mountains. It occupies an area of 67.46 km2 and the length of the main stream is about 24.5 km. Due to the fact that flooding in this watershed threats the downstream rural areas, an investigation was carried out to extract its geomorphologic characteristics and evaluate their contribution in flood production. In this regard, the watershed area was divided into 4 sections based on physiographic and topographic characteristics and stream network: A1 (the southern, low-height part), A2 (mid-western half), A3 (mid-eastern half) and A4 (the northern and highest part). Hypsometric maps and diagrams prepared for the area show that it is confined between 1390 and 3230m elevation levels with a general dip towards the south. The main part of it (57.93%) is located between the elevation levels of 1390 and 1500m. Using the precipitation records of 4 neighboring stations for 20 years, the estimated time of concentration for the runoff varies in the sub-zones: 1.64 hr in A1 (13.9 km stream length and 710 m altitude difference), 0.63 hr in A2 (7.2 km and 1200 m), 0.35 hr in A3 (4.7 km and 1530 m) and 0.48 hr in A4 (5.9 km and 1330 m.) Dip angle is one of the most important factors affecting the time of concentration for runoff and flood production. The average dip of the main part of the area (79.82%) ranges between 0 and 5°, while only the 0.44% of the area has dips about 30-40°. Highest dips are found in the A4 zone (0-40°) and the weight average dip of the total area is 12.94%. Geologically, the most widespread rocks are Pre-Cambrian shales, schists and limestones (Kahar Formation, 43.53%), upper-Cretaceous flysch sequence comprised of shale, limestone and sandstone (13.99%), Miocene marls, silts, clays and limestones (4.13%) and Quaternary alluvial terraces and plains (30.33%). Geomorphologically, this watershed is comprised of 3 types of lands: (1

  14. Deriving hydrologic conditions in the southern Caucasus region during the Little Ice Age using different geomorphological and paleoenvironmental archives (United States)

    von Suchodoletz, Hans; Benito, Dario Martin; Pederson, Neil; Faust, Dominik


    From the 15th century to ca. 1850 AD, the Little Ice Age (LIA), was one of the most prominent climatic fluctuations during the Holocene. It was characterized by negative temperature anomalies evidenced for many regions of the Northern Hemisphere (Mann 2002). During the LIA, many of these regions showed significant changes of their landscape dynamics such as glacier advances and an intensified hydrological cycle. Although glacier advances and reduced pine growth are reported from the Greater Caucasus for parts of the LIA (Solomina 2005), little is known about the hydrological conditions of the humid to semi-arid Lesser Caucasus and Transcaucasus region during the LIA. Existing pollen records are so strongly disturbed by anthropogenic activity during the last millenia that the LIA is not resolved in the only existing pollen-based precipitation reconstruction for the region (Connor & Kvavadze 2008). Here, we present data derived from different kinds of geomorphological archives from the southern Caucasus region (fluvial sediments, indicators for the timing of incision of recently dry valleys). These data demonstrate intensive geomorphic activity during the LIA obviously caused by a strongly intensified hydrological cycle. Given the rather low temporal resolution of these geomorphological archives, however, more highly-resolved palaeoenvironmental data are needed to better understand also minor climatic and hydrologic fluctuations around the LIA period. To this end, we intend to use a recently developed multispecies tree-ring network from living trees (Martin-Benito et al., in revision). This tree-ring network will be expanded both in space and time using subfossil wood material (stems) found embedded into fluvial LIA-terrace deposits and radiocarbon-dated to the end of the 15th century AD. By overlapping these samples with the living tree network, we will be able to better characterize sub-ordinate climatic and hydrologic fluctuations during the LIA period. References

  15. The geologic and geomorphologic evolution of Serranía Huanchaca, eastern Bolivia: The legendary ``Lost World'' (United States)

    Litherland, M.; Power, G.

    Serranía Huanchaca is a remote tableland in eastern Bolivia with an area of about 7000 km 2. It is bounded by precipitous cliffs which overlook the densely forested lowlands of the southern Amazonian basin. Descriptions of the cliffs by the English explorer Col. Fawcett formed the basis for the novel The Lost World by Arthur Conan Doyle. The serranía is composed mainly of unmetamorphosed arenaceous Proterozoic sediments which comprise the Huanchaca Group. This unconformably overlies a basement complex of schists and granites which were generated at c. 1300 Ma. The Huanchaca Group sediments are interpreted as fluvial deposits which were derived from the north. Around 900 Ma, these sediments were intruded by a continental tholeiitic sill and dike complex, while the marginal effects of the Aguapei Mobile Belt produced a pattern of monoclinal folds in the form of a structural basin. This basin was later infilled by sandstones of the Macacos Group, of possible Cretaceous age, and the entire sequence was affected by the Cretaceous post-Macacos episode of faulting, jointing and minor folding, accompanied by the formation of siliceous reefs of quartz breccia and chert. The geomorphologic evolution of the serranía can be related to successive Tertiary cycles of erosion which, in order of decreasing age, produced the Pega Pega, Paucerna, and San Ignacio planation surfaces and associated laterites as well as sandstones, cherts, and silcretes found locally over the serranía. The keel of more resistant Huanchaca Group quartzites has helped preserve the Pega Pega and Paucerna surfaces over the serranía; elsewhere in eastern Bolivia, these have been removed by the San Ignacio cycle of erosion.

  16. The seafloor geomorphology of the Windmill Islands, Wilkes Land, East Antarctica: Evidence of Law Dome ice margin dynamics (United States)

    Carson, C. J.; Post, A. L.; Smith, J.; Walker, G.; Waring, P.; Bartley, R.; Raymond, B.


    A high-resolution multibeam sonar dataset covering an area of ca. 33 km2 was collected in the vicinity of the Windmill Islands (67°S, 110°E), Wilkes Land, East Antarctica. The new data permit visualisation of the nearshore seafloor morphology in unprecedented detail, providing invaluable insight into the ice-sheet history of the region. A range of geomorphic features are evident, including prominent parallel northwest-trending linear fault sets affecting Mesoproterozoic metamorphic basement, which appear to control the regional coastal physiography. The fault systems probably formed during fragmentation of eastern Gondwana during the Mesozoic. Networks of sub-glacial meltwater channels, preserved on bedrock platforms and ridges, indicate grounding of a thick ice sheet over the continental shelf during previous glaciations. West-trending subtle glacial lineations and streamlined landforms record evidence of the westward expansion of the grounded Law Dome ice sheet margin, probably during the late Pleistocene. The direction of these features coincides with glacial striae on onshore crystalline bedrock outcrops. Perhaps the most striking glacial geomorphological features are sets of arcuate ridges confined mostly within glacially excavated U-shaped troughs formed by erosion of the northwest-trending bedrock fault sets. These ridge sets are interpreted as push moraines or grounding zone features, formed during episodic retreat of highly channelised, topographically-controlled ice-streams following ice surging of the Law Dome margin. This event was possibly triggered in response to local environmental forcing during the mid-late Holocene. Minor post-glacial marine sedimentation is preserved in several small (≤ 1 km2) isolated basins with shallow seaward sills.

  17. Groundwater arsenic contamination from parts of the Ghaghara Basin, India: influence of fluvial geomorphology and Quaternary morphostratigraphy (United States)

    Shah, Babar Ali


    A groundwater arsenic (As) distribution in Faizabad, Gonda, and Basti districts of Uttar Pradesh is shown in the entrenched channels and floodplains of the Ghaghara River. Tubewell water samples were analysed for As through flow injection hydride generation atomic absorption spectrometry (FI-HG-AAS) system. About 38, 61, and 42 % of tubewells in Faizabad, Gonda, and Basti districts, respectively, have As >10 µg/l (WHO guideline). Moreover, 15, 45, and 26 % of tubewells in Faizabad, Gonda, and Basti districts, respectively, have As above 50 µg/l. About 86, 69, and 35 % of tubewells in Faizabad, Gonda, and Basti districts, respectively, are from shallow depth (21-45 m), and it is worth noticing that 47 % As-contaminated (As >10 µg/l) tubewells in these three districts are located within the depth of 10-35 m in Holocene Newer Alluvium aquifers. The high content of As (7.11 mg/kg) is measured in suspended river sediments of the Ghaghara River. Most of the As-contaminated villages in the Ghaghara Basin are located close to abandoned or present meander channels and floodplains of the Ghaghara River. In contrast, tubewells in Faizabad, Ayodhya, and Nawabganj towns are As-safe because of their positions on the Pleistocene Older Alluvium upland surfaces. Quaternary geomorphology plays an important role in groundwater arsenic contamination in the Ghaghara Basin. The sources of groundwater arsenic are geogenic and perennial mountainous rivers in the Ghaghara Basin supplied high sediment loads. The arsenic in groundwater of Ghaghara Basin is getting released from associated sediments which were likely deposited from the Himalayas. The process of release of groundwater arsenic is reductive dissolution of iron hydroxides.

  18. Regional scale hydrologic modeling of a karst-dominant geomorphology: The case study of the Island of Crete (United States)

    Malagò, Anna; Efstathiou, Dionissios; Bouraoui, Fayçal; Nikolaidis, Nikolaos P.; Franchini, Marco; Bidoglio, Giovanni; Kritsotakis, Marinos


    Crete Island (Greece) is a karst dominated region that faces limited water supply and increased seasonal demand, especially during summer for agricultural and touristic uses. In addition, due to the mountainous terrain, interbasin water transfer is very limited. The resulting water imbalance requires a correct quantification of available water resources in view of developing appropriate management plans to face the problem of water shortage. The aim of this work is the development of a methodology using the SWAT model and a karst-flow model (KSWAT, Karst SWAT model) for the quantification of a spatially and temporally explicit hydrologic water balance of karst-dominated geomorphology in order to assess the sustainability of the actual water use. The application was conducted in the Island of Crete using both hard (long time series of streamflow and spring monitoring stations) and soft data (i.e. literature information of individual processes). The KSWAT model estimated the water balance under normal hydrological condition as follows: 6400 Mm3/y of precipitation, of which 40% (2500 Mm3/y) was lost through evapotranspiration, 5% was surface runoff and 55% percolated into the soil contributing to lateral flow (2%), and recharging the shallow (9%) and deep aquifer (44%). The water yield was estimated as 22% of precipitation, of which about half was the contribution from spring discharges (9% of precipitation). The application of the KSWAT model increased our knowledge about water resources availability and distribution in Crete under different hydrologic conditions. The model was able to capture the hydrology of the karst areas allowing a better management and planning of water resources under scarcity.

  19. Investigation of the Qadimah Fault in Western Saudi Arabia using Satellite Radar Interferometry and Geomorphology Analysis Techniques

    KAUST Repository

    Smith, Robert


    The Qadimah Fault has been mapped as a normal fault running through the middle of a planned $50 billion city. For this reason, there is an urgent need to evaluate the seismic hazard that the fault poses to the new development. Although several geophysical studies have supported the existence of a fault, the driving mechanism remains unclear. While a fault controlled by gravity gliding of the overburden on a mobile salt layer is unlikely to be of concern to the city, one caused by the continued extension of a normal rotational fault due to Red Sea rifting could result in a major earthquake. A number of geomorphology and geodetic techniques were used to better understand the fault. An analysis of topographic data revealed a sharp discontinuity in slope aspect and hanging wall tilting which strongly supports the existence of a normal fault. A GPS survey of an emergent reef platform which revealed a tilted coral surface also indicates that deformation has occurred in the region. An interferometric synthetic aperture radar investigation has also been performed to establish whether active deformation is occurring on the fault. Ground movements that could be consistent with inter-seismic strain accumulation have been observed, although the analysis is restricted by the limited data available. However, a simple fault model suggests that the deformation is unlikely due to continued crustal stretching. This, in addition to the lack of footwall uplift in the topography data, suggests that the fault is more likely controlled by a shallow salt layer. However, more work will need to be done in the future to confirm these findings.

  20. Cretaceous—Quaternary tectonic evolution of the Tatra Mts (Western Carpathians: constraints from structural, sedimentary, geomorphological, and fission track data

    Directory of Open Access Journals (Sweden)

    Králiková Silvia


    Full Text Available The Tatra Mts area, located in the northernmost part of Central Western Carpathians on the border between Slovakia and Poland, underwent a complex Alpine tectonic evolution. This study integrates structural, sedimentary, and geomorphological data combined with fission track data from the Variscan granite rocks to discuss the Cretaceous to Quaternary tectonic and landscape evolution of the Tatra Mts. The presented data can be correlated with five principal tectonic stages (TS, including neotectonics. TS-1 (~95-80 Ma is related to mid-Cretaceous nappe stacking when the Tatric Unit was overlain by Mesozoic sequences of the Fatric and Hronic Nappes. After nappe stacking the Tatric crystalline basement was exhumed (and cooled in response to the Late Cretaceous/Paleogene orogenic collapse followed by orogen-parallel extension. This is supported by 70 to 60 Ma old zircon fission track ages. Extensional tectonics were replaced by transpression to transtension during the Late Paleocene to Eocene (TS-2; ~80-45 Ma. TS-3 (~45-20 Ma is documented by thick Oligocene-lowermost Miocene sediments of the Central Carpathian Paleogene Basin which kept the underlying Tatric crystalline basement at elevated temperatures (ca. > 120 °C and < 200 °C. The TS-4 (~20-7 Ma is linked to slow Miocene exhumation rate of the Tatric crystalline basement, as it is indicated by apatite fission track data of 9-12 Ma. The final shaping of the Tatra Mts has been linked to accelerated tectonic activity since the Pliocene (TS-5; ~7-0 Ma.

  1. Characterizing worldwide patterns of fluvial geomorphology and hydrology with the Global River Widths from Landsat (GRWL) database (United States)

    Allen, G. H.; Pavelsky, T.


    The width of a river reflects complex interactions between river water hydraulics and other physical factors like bank erosional resistance, sediment supply, and human-made structures. A broad range of fluvial process studies use spatially distributed river width data to understand and quantify flood hazards, river water flux, or fluvial greenhouse gas efflux. Ongoing technological advances in remote sensing, computing power, and model sophistication are moving river system science towards global-scale studies that aim to understand the Earth's fluvial system as a whole. As such, a global spatially distributed database of river location and width is necessary to better constrain these studies. Here we present the Global River Width from Landsat (GRWL) Database, the first global-scale database of river planform at mean discharge. With a resolution of 30 m, GRWL consists of 58 million measurements of river centerline location, width, and braiding index. In total, GRWL measures 2.1 million km of rivers wider than 30 m, corresponding to 602 thousand km2 of river water surface area, a metric used to calculate global greenhouse gas emissions from rivers to the atmosphere. Using data from GRWL, we find that ~20% of the world's rivers are located above 60ºN where little high quality information exists about rivers of any kind. Further, we find that ~10% of the world's large rivers are multichannel, which may impact the development of the new generation of regional and global hydrodynamic models. We also investigate the spatial controls of global fluvial geomorphology and river hydrology by comparing climate, topography, geology, and human population density to GRWL measurements. The GRWL Database will be made publically available upon publication to facilitate improved understanding of Earth's fluvial system. Finally, GRWL will be used as an a priori data for the joint NASA/CNES Surface Water and Ocean Topography (SWOT) Satellite Mission, planned for launch in 2020.

  2. On hydrologic similarity: A dimensionless flood frequency model using a generalized geomorphologic unit hydrograph and partial area runoff generation (United States)

    Sivapalan, Murugesu; Wood, Eric F.; Beven, Keith J.


    One of the shortcomings of the original theory of the geomorphologic unit hydrograph (GUH) is that it assumes that runoff is generated uniformly from the entire catchment area. It is now recognized that in many catchments much of the runoff during storm events is produced on partial areas which usually form on narrow bands along the stream network. A storm response model that includes runoff generation on partial areas by both Hortonian and Dunne mechanisms was recently developed by the authors. In this paper a methodology for integrating this partial area runoff generation model with the GUH-based runoff routing model is presented; this leads to a generalized GUH. The generalized GUH and the storm response model are then used to estimate physically based flood frequency distributions. In most previous work the initial moisture state of the catchment had been assumed to be constant for all the storms. In this paper we relax this assumption and allow the initial moisture conditions to vary between storms. The resulting flood frequency distributions are cast in a scaled dimensionless framework where issues such as catchment scale and similarity can be conveniently addressed. A number of experiments are performed to study the sensitivity of the flood frequency response to some of the 'similarity' parameters identified in this formulation. The results indicate that one of the most important components of the derived flood frequency model relates to the specification of processes within the runoff generation model; specifically the inclusion of both saturation excess and Horton infiltration excess runoff production mechanisms. The dominance of these mechanisms over different return periods of the flood frequency distribution can significantly affect the distributional shape and confidence limits about the distribution. Comparisons with observed flood distributions seem to indicate that such mixed runoff production mechanisms influence flood distribution shape. The

  3. Geomorphology of the Alluvial Sediments and Bedrock in an Intermontane Basin: Application of Variogram Modeling to Electrical Resistivity Soundings (United States)

    Khan, Adnan Ahmad; Farid, Asam; Akhter, Gulraiz; Munir, Khyzer; Small, James; Ahmad, Zulfiqar


    The study describes a methodology used to integrate legacy resistivity data with limited geological data in order to build three-dimensional models of the near subsurface. Variogram analysis and inversion techniques more typically found in the petroleum industry are applied to a set of 1D resistivity data taken from electrical surveys conducted in the 1980s. Through careful integration with limited geological data collected from boreholes and outcrops, the resultant model can be visualized in three dimensions to depict alluvium layers as lithological and structural units within the bedrock. By tuning the variogram parameters to account for directionality, it is possible to visualize the individual lithofacies and geomorphological features in the subsurface. In this study, an electrical resistivity data set collected as part of a groundwater study in an area of the Peshawar basin in Pakistan has been re-examined. Additional lithological logs from boreholes throughout the area have been combined with local outcrop information to calibrate the data. Tectonic activity during the Himalayan orogeny has caused uplift in the area and generated significant faulting in the bedrock resulting in the formation of depressions which are identified by low resistivity values representing clays. Paleo-streams have reworked these clays which have been eroded and replaced by gravel-sand facies along paleo-channels. It is concluded that the sediments have been deposited as prograding fan-shaped bodies and lacustrine deposits with interlayered gravel-sand and clay-silt facies. The Naranji area aquifer system has thus been formed as a result of local tectonic activity with fluvial erosion and deposition and is characterized by coarse sediments with high electrical resistivities.

  4. The response of polar glaciers to Late Holocene climate change reconstructed from terrestrial geomorphological evidence on Svalbard (United States)

    Lukas, Sven; Benn, Douglas I.; Temminghoff, Maria; Boston, Clare M.; Irvine-Fynn, Tris; Porter, Philip R.; Barrand, Nick E.; Nicholson, Lindsey I.; Ross, Fionna H.; Humlum, Ole


    Arctic ice masses are likely to experience some of the most dramatic changes in the context of projected atmospheric warming. Understanding how quickly and in what form these changes will manifest themselves is important in order to be able to predict future impacts, through feedback mechanisms, on the climate at different spatial scales, ranging from local to global. In addition to this, it is also important to consider various temporal scales to obtain a longer-term perspective beyond historical and instrumental records. In order to assess modes of glacier response against this background we present results from four terrestrial glaciers on Svalbard, three of which are located in a semi-arid climate and one in a maritime setting with a humid climate. We have employed a multi-disciplinary approach comprising geomorphological mapping, sedimentological logging and analyses, process observations, differences between digital elevation models constructed for different years and DC resistivity surveys of glacier snouts and forelands to arrive at a holistic process understanding of glacier response to Late Holocene climate change and to tease apart climatic controls on their response. Our results show that the presence of debris overlying buried ice blocks and continuous glacier ice bodies in a continuous permafrost environment complicates the relationship between climatic warming and glacier response. Processes in foreland evolution are intimately linked to debris thickness and distribution on the one hand and to the evolution and reorganisation of the sub-, en- and proglacial drainage system which controls where material evacuation and thus debris-cover thinning and removal takes place. In our contribution, we will discuss the processes in detail and will develop a conceptual model that will allow the response of arctic glaciers to be placed into a wider framework that incorporates neoglacial and current times.

  5. Evaluation of Development of the Mitchell Creek Landslide, B.C., using Remote Sensing, Geomorphological Analysis and Numerical Modelling (United States)

    Stead, D.; Clayton, A.


    The Mitchell Creek Landslide of northwestern British Columbia is a large structurally controlled bedrock instability, with an estimated volume of 75 Mm3. It has developed over the last 60 years in response to rapid deglaciation, offering insight into changing conditions at juvenile rock landslides. The landslide is located in altered volcanic & volcaniclastic rocks of the Stikine Terrane at the intersection of two major regional faults. Multiple failure mechanisms have been identified over the 0.8 km2 landslide area including toppling along steep foliation in the lower landslide and sliding along a well-defined rupture surface in the upper landslide. Geomorphological and engineering geological assessments have been completed at the site to characterize landslide properties and behaviour. Historic aerial photographs have been used to observe changes to the slope since 1956 and have captured the onset of surface deformation. Mapping of morphological and deformation features were undertaken on imagery from 1956, 1972, 1992, and 2010 to evaluate slope processes, failure mechanisms, and damage accumulation within the slope. Natural targets were also used to estimate landslide displacements over the past 60 years. Annual movement rates have been estimated to range from 0.1 to 0.8 m/yr over the landslide area. Displacement rates have been compared with historic glacial levels in the valley and modern environmental monitoring. A reconstruction of pre-failure geometry of the landslide was created from displacement estimates and structural geologic information. Rock mass properties and discontinuity orientations have been assessed from geotechnical investigations carried out between 2008 and 2013. A conceptual model of landslide behaviour and evolution has been developed and evaluated using both continuum and discontinuum numerical modeling techniques.

  6. A review of the chronologies and geomorphology of the aeolian landforms in the northwestern Negev dunefield (Israel) (United States)

    Roskin, Joel


    The northwestern (NW) Negev Desert dunefield covering an area of only 1,300 km2, comprises the eastern end of the northern Sinai Peninsula - NW Negev erg and is probably the most densely dated dune body in the INQUA Dunes Atlas chronologic database. Over 230 luminescence ages (TL, IRSL, and mainly OSL) and radiocarbon dates have been retrieved over the past course of 20 years from calcic and sandy palaeosols serving as dune substrates, sand sheets, vegetated linear dunes (VLDs), fluvial deposits, and archaeological sites. Despite being from different deposit types and aeolian morphologies, and based on different methodologies, the chronologies usually show good compatibility. By reviewing and reassessing the significance of the Eastern Mediterranean INQUA Dunes Atlas chronologies, along with detailed stratigraphic, structural and geomorphologic data and understandings, the major, and possibly extreme, episodes of aeolian activity and stability are outlined. Repetitive chronostratigraphic sequences in VLDs indicate that this dune type, at least in the Negev, comprises a reliable recorder of main dune mobilization periods. This presentation demonstrates that certain combinations of research finds, using different OSL dating strategies and other regional and local late Quaternary records and in particular aeolian ones, are required assets for providing for acceptable local and regional palaeoclimatic interpretations. The distribution of the VLD chronologies points to rapid mobilization during the Heinrich 1 and Younger Dryas, characterized by powerful winds, though VLDs also form in late Holocene palaeoenvironments. Time slices illustrate the different sensitivities of the studied aeolian landforms to the source, availability, and supply of sediment; long- and short-term climate change, local human-induced environmental changes and also their joint effects, that enable evaluation of aeolian responses to future environmental and climate changes.

  7. Groundwater arsenic contamination from parts of the Ghaghara Basin, India: influence of fluvial geomorphology and Quaternary morphostratigraphy (United States)

    Shah, Babar Ali


    A groundwater arsenic (As) distribution in Faizabad, Gonda, and Basti districts of Uttar Pradesh is shown in the entrenched channels and floodplains of the Ghaghara River. Tubewell water samples were analysed for As through flow injection hydride generation atomic absorption spectrometry (FI-HG-AAS) system. About 38, 61, and 42 % of tubewells in Faizabad, Gonda, and Basti districts, respectively, have As >10 µg/l (WHO guideline). Moreover, 15, 45, and 26 % of tubewells in Faizabad, Gonda, and Basti districts, respectively, have As above 50 µg/l. About 86, 69, and 35 % of tubewells in Faizabad, Gonda, and Basti districts, respectively, are from shallow depth (21-45 m), and it is worth noticing that 47 % As-contaminated (As >10 µg/l) tubewells in these three districts are located within the depth of 10-35 m in Holocene Newer Alluvium aquifers. The high content of As (7.11 mg/kg) is measured in suspended river sediments of the Ghaghara River. Most of the As-contaminated villages in the Ghaghara Basin are located close to abandoned or present meander channels and floodplains of the Ghaghara River. In contrast, tubewells in Faizabad, Ayodhya, and Nawabganj towns are As-safe because of their positions on the Pleistocene Older Alluvium upland surfaces. Quaternary geomorphology plays an important role in groundwater arsenic contamination in the Ghaghara Basin. The sources of groundwater arsenic are geogenic and perennial mountainous rivers in the Ghaghara Basin supplied high sediment loads. The arsenic in groundwater of Ghaghara Basin is getting released from associated sediments which were likely deposited from the Himalayas. The process of release of groundwater arsenic is reductive dissolution of iron hydroxides.

  8. Near surface geophysics techniques and geomorphological approach to reconstruct the hazard cave map in historical and urban areas (United States)

    Lazzari, M.; Loperte, A.; Perrone, A.


    This work, carried out with an integrated methodological approach, focuses on the use of near surface geophysics techniques, such as ground penetrating radar GPR and electrical resistivity tomography (ERT), and geomorphological analysis, in order to reconstruct the cave distribution and geometry in a urban context and, in particular, in historical centres. In fact, there are a lot of historical Mediterranean sites born on an original rupestrian settlement, of which often the new generations forgot the memory and new urban areas built on them burying any marks. The interaction during recent centuries between human activity (caves excavation, birth and growth of an urban area) and the characters of the natural environment were the reasons of a progressive increase in hazard and vulnerability levels of several sites. The reconstruction of a detailed cave map distribution is the first step to define the anthropic and geomorphological hazard in urban areas, fundamental basis for planning and assessing the risk. The integrated near surface geophysics and geomorphological techniques have been applied to the case study of Tursi hilltop town and its older nucleus called Rabatana, located in the south-western sector of the Basilicata (southern Italy), representing an interesting example of the deep bond between natural and man-made environments such as precious cultural heritage. The history of this settlement has always been deeply connected with the characteristics of the neighbouring environment and it seems possible that the first settlement was built by excavating the slopes of the sandy relief. It was a typical rupestrian settlement, where meteoric water was stored inside some cisterns excavated on the slopes. During recent centuries, the increase in territory development by humans produced an increase in cave excavation in the Tursi-Rabatana urban area. To reconstruct the extremely complex near-surface hypogeal environment excavated in the sandy layers, a geophysical

  9. 《中华人民共和国地貌图集》的研究与编制%Research and compilation of the Geomorphologic Atlas of the People's Republic of China(1:1,000,000)

    Institute of Scientific and Technical Information of China (English)

    程维明; 周成虎; 柴慧霞; 赵尚民; 刘海江; 周增坡


    Geomorphologic maps are one of the most fundamental materials of the natural environment. They have been widely used in scientific research, resource exploration and extraction, education and military affairs etc. An editorial committee was established in 2001 to collect materials for researching and compiling a set of new 1:1,000,000 geomorphologic atlas of China. A digital geomorphologic database was created with visual interpretation from Landsat TM/ETM imageries and SRTM-DEM etc. The atlas compiled from the database was finished. The main characteristics of the atlas are as follows: Firstly, Landsat TM/ETM imageries, published geomorphologic maps or sketches, geographical base maps, digital geological maps, and other thematic maps were collected, which were uniformly geometrically rectified, clipped into uniform sheets, and stored in the foundation database. Secondly, based on the legends of 15 sheets 1:1,000,000 maps published in the 1980s, a geomorphologic classification system was built by combining morphology and genesis types. The system comprised seven hierarchical layers: basic morphology, genesis, sub-genesis, morphology,micro-morphology, slope and aspect, material composition and lithology. These layers were stored in the database during visual image interpretation. About 2000 kinds of mor-pho-genesis and 300 kinds of morpho-structure were interpreted. Thirdly, the legend system was built, which included color, symbol bases and note bases etc., compilation standards and procedures were developed, 74 sheets of 1:1,000,000 covering all land and sea territories of China were compiled, the 1:1,000,000 geomorphologic atlas of the People's Republic of China was finished and published. The atlas will fill the blanks in national basic scale thematic maps, and the geomorphologic database could be applied widely in many fields in the future.

  10. Geomorphological survey and remote sensing analysis: a multidisciplinary approach to reconstruct triggering factors of a DSGSD in Maso Corto (South Tyrol, Italy) (United States)

    Amato, Gabriele; Fubelli, Giandomenico; Piccin, Gianluca; Chinellato, Giulia; Iasio, Christian; Mosna, David; Morelli, Corrado


    In the Alpine regions, it is essential and urgent to define an improved and specific set of monitoring methods for the evolution of instability phenomena in order to avoid the closure of the installations because of the occurrence of natural calamities and to ensure the safety of citizens. In this context the SloMove Project aims at consolidate know-how of the ordinary monitoring applications of surface movements, evaluate their pros and cons and optimize the expected technical procedures of investigation. Within the SloMove project, an experimental composite monitoring has been carried out in the touristic site of Maso Corto (South Tyrol, Italy). Structural-Geomorphological Survey, GPS measurements and Time series analysis of SAR Interferometry data have been integrated. The purposes of this experiment are: 1) to reconstruct the geomorphological dynamics and their state of activity; 2) to provide considerations on the role of permafrost as an influential factor for landslide activity. Structural-Geomorphological survey highlighted control of structural asset of the outcropping lithologies on geomorphological markers, such as trenches, counterscarps, outcropping sliding surfaces. The area is characterized by metamorphic rocks, affected by foliation oriented between N350 and N30. Moreover, joints due to frost thaw activity are common in the shallow portions and the presence of two sets of tectonics fractures (N45, 45°-60° and N360, sub-vertical) has been recognized. In order to evaluate the state of permafrost, rock glaciers in the area have been investigated. SAR interferometry data have been processed by TRE® through the SqueeSAR™ analysis using Radarsat and Envisat images acquired during a period between 2003 and 2009. GPS surveys were carried out through the technique of Rapid-Static Relative Positioning during the summer months of 2012 and 2013. Data shows that an area of 2km2, north of Maso Corto, is affected by a Deep Seated Gravitational Slide

  11. Tectonic geomorphology of the 21 May 2003 Zemmouri earthquake area (Mw 6.8, Tell Atlas, Algeria) : An analysis of the long-term coastal uplift (United States)

    Bagdi-Issaad, Souhila; Meghraoui, Mustapha; Nedjari, Ahmed


    Geomorphological, geological and structural markers attest for successive uplift during the late Quaternary along the Algerian coastal region, a section of the Africa-Eurasia plate boundary. Large and moderate shallow earthquakes with Mw ≥ 6 occurred on E-W to NE-SW active thrust-related-fold structures an among them the 21 May 2003 Zemmouri earthquake (Mw 6.8) that caused 0.5 m uplift on 55 km coastal. In this work, we study the correlation between the 2003 coseismic uplift with the long-term active deformation using the distribution of Quaternary marine and alluvial terraces where indicators show three pre-2003 main notch levels formed in the last 21.9 ka along with five alluvial terrace levels formed in Pleistocene. The analysis of drainage system and related tectonic geomorphology along the coastal area show over 500 small and large rivers that document the trend of present-day and past stream channels, their longitudinal profiles, the arrangement of Quaternary deposits and the response of river mouths to the successive past and recent uplift. The analysis of remote sensing images combined with high-resolution Digital Elevation Model and field observations reveal concave downward shape of most river profiles and river mouth deflections near the coastline. Data previously obtained on the coseismic deformation using coastal tectonics, seismology and geodetic (InSAR and GPS) investigations are combined to our analysis of coastal deformation. The results confirm the impact of the offshore thrust fault responsible of the coastal deformation through successive coseismic uplift with an estimated average 0.9 to 2.1 mm/year during the late Pleistocene - Holocene (Maouche et al.,2011). The short-term and long-term deformation and related surface slip distribution controls the drainage system and related distribution of Quaternary deposits. Our results indicate how the tectonic geomorphology can be a decisive marker for the identification of coastal active faults and

  12. Floodplain restoration on the upper Danube by re-establishing back water dynamics: first results of the hydro-geomorphological monitoring (United States)

    Fischer, Peter; Hilger, Ludwig; Cyffka, Bernd


    Within the framework of a restoration project at the upper Danube, eight working groups of different scientific disciplines have been operating since 2009. They investigate the changes evoked through the accomplished restoration measures, which seek to bring back new dynamics to the floodplain and to reconnect it with the river in order to optimize flood plain ecological functioning. Main object is the identification and analysis of hydro-geomorphological processes and their impact on vegetation and fauna. Hydrology is one of the key factors determining the type and function of flood plains and thus alternating water levels are the motor of riparian ecosystems. Diverse water and groundwater levels and particularly flood events affect and support floodplain typical vegetation and animal species. All floodplain waterbodies (oxbows, floodplain ponds, backwaters and sidearms) are more or less connected by surface or subsurface waterways. Hydrological conditions are mainly influenced by the following measures: a, permanent nature orientated bypass river with a discharge of up to 5 m3/s; b, man controlled ecological flooding (discharge of up to 30 m3/s); c, groundwater drawdown in the eastern project area. These measures shall bring back "former" natural hydrological dynamics to the floodplain. They establish geomorphological processes and forms as well and create a mosaic of typical habitats. River morphology is monitored by terrestrial laser scanning analysing the so attained data sets, erosion and aggregation rates at selected undercut slopes and point bars can be detected with a high resolution. Large scale mapping by a drone and dGPS mapping are very helpful tools for identifing widespread flooding areas. Further methods such as, cross section and bed load measurements complete the research work. The aim is to link the interaction of these abiotic processes with the biotic nature and determine the importance of geomorphological disturbance for floodplain ecosystems

  13. Seismo-tectonic divisions of strong earth-quakes with MS37.0 and their tectonic geomorphology along Xianshuihe-Xiaojiang fault zone

    Institute of Scientific and Technical Information of China (English)

    张世民; 谢富仁


    Seismo-tectonic areas of historical strong earthquakes with MS37 along Xianshuihe-Xiaojiang fault zone are di-vided, and their individual fault-pattern and tectonic geomorphology are analyzed. Those strong-earthquake areas are located in some special parts of the fault zone, where the major branch-faults of the fault zone form left step-ping, parallel, and fork-like patterns. In the strong-earthquake areas structurally complicated basins are developed, such as pull-apart basins in fork-like area, in double stepping area, and in stepping and fork-like areas.

  14. Geomorfološki razvoj doline Krnice in njene zadnje poledenitve = Geomorphological development of the Krnica valley and its late glaciation

    Directory of Open Access Journals (Sweden)

    Jurij Kunaver


    Full Text Available The paper deals with the geomorphological development of the elongated Krnica valley in the Julian Alps near Kranjska gora, which geneticaly resembles to the Vršič Pass. The basic idea is the development of this Alpine valley under the strong influence of the softer dolomitic strata which is beneath the limestone. Besides, the fault lines contribute a lot to this development. Not only the frontal moraines in the valley itself but also the two of them near Kranjska gora can be the result of the same late postwürmian stadial glacier, as this was the longest in the region.

  15. 中国热带第四纪板块运动的地貌效应%Geomorphological effects of plate movement during Quaternary in China's tropics

    Institute of Scientific and Technical Information of China (English)

    张伟强; 黄镇国


    The eastern and western fronts of plate movement in Taiwan Island and Tibetan Plateau respectively are the two major sources of tectonic force for the morphogensis during Quaternary in China′s tropics. Seven examples of geomorphological effects of plate movement are enumerated to discuss the differentiation of tectonic landforms in space and time during Quaternary. The tectonic movement tends to be more active since middle Pleistocene. Some phenomena such as the arc-shape mountain systems, volcanism and crustal deformation imply that the juncture zone of eastern and western tectonic forces is located at about 1 1O°E.

  16. Digital photogrammetry and GIS-based analysis of the bio-geomorphological evolution of Sakurajima Volcano, diachronic analysis from 1947 to 2006 (United States)

    Gomez, Christopher


    The Sakurajima Volcano is one of the most active volcanoes in the world with regular activity dominated by vulcanian eruptions since 1955. Located in Kagoshima Prefecture - Kyushu Island, Japan - the Sakurajima Volcano is a stratovolcano with two main vents at the summit, the Kitadake and the Minamidake, and a third smaller central vent, the Nakadake. The two firsts peak at 1117 and 1060 m dominate the slopes mainly composed of lava-flow deposits, secondary volcaniclastic material and recent ejectas from the Vulcanian eruptions. Although the volcano has been very closely monitored by Japanese Universities (mostly Kyoto University and Kagoshima University) and governmental agencies, there has been very little geomorphological investigation of the structure of the volcano. Using the digital photogammetric method SfM-MVS (Structure from Motion and Multiple-view Stereophotogrammetry) applied to historical aerial photographs, the present contribution aims to provide an analysis of the volcanic structure and the recent bio-geomorphological evolution for the period 1947-2006. First, the results have proved that SfM-MVS is a method that can be successfully applied to aerial photographs for diachronic reconstruction of geomorphological landscape evolution. This method is especially important in active volcanic areas, as the geomorphology can change very rapidly within the historical period. Secondly, the results have shown that during the last ~ 60 years, the summit area of the Sakurajima has greatly evolved: the morpholology of the Minamidake crater has changed due to its regular explosive activity; the upper slopes have been covered in ejecta, modifying their elevation and their smoothness. The lower slopes have seen the apparition of lahar deposition areas, while valleys, upslope, have widened due to the lahar activity and the upward progression of the deposits. The 3D derived from SfM-MVS has also shown how the lahar deposits are using the topographic low, created on

  17. Geomorphology and preservation potential of coastal and submerged aeolianite: Examples from KwaZulu-Natal, South Africa (United States)

    Cooper, J. Andrew G.; Green, Andrew N.


    The distribution and geomorphology of aeolianite outcrop on the coast of KwaZulu-Natal, South Africa are described in the context of its preservation potential in the geological record. Aeolianite on the contemporary coast comprises discontinuous, widely spaced, outcrops less than 100 m in longshore extent and typically 50-60 m wide that reflects the combined action of subaerial weathering and physical abrasion in the coastal zone since the mid-Holocene (approximately 7000 yrs). The dominant morphological component is an intertidal erosional platform that slopes gently landward. It is fronted by a notch in the mid intertidal zone (0 m MSL) and contains active erosional potholes on its seaward margin. The platform surface is encrusted by a variety of marine organisms. Landward of and contiguous with the intertidal surface are small elevated outcrops of aeolianite in the supratidal zone. These comprise a 3 m-high seaward scarp with a basal notch in the high intertidal zone + 1 m MSL. Gullies in the scarp trap coarse clasts of eroded aeolianite as well as bedrock. The upper surface of the supratidal aeolianite is planar with large potholes within which accumulations of coarse clasts and oyster shells have been cemented. The upper surface is interpreted as a remnant of an intertidal platform formed at a higher mid-Holocene sea level. The supratidal outcrop is subject to weathering and disintegration. Major joints divide the outcrop into cuboid blocks with axes of 3-4 m. Eroded blocks on the seaward face that exceed 1 m diameter, remain in-situ and become locked in place by repeated shaking. Smaller blocks that collapse from the seaward face accumulate in small gullies or are dispersed. The facet most likely to be preserved in the geological record is the planar intertidal platform. The morphology of aeolianite on the contemporary coast is markedly different from submerged aeolianite ridges on the adjacent shelf which are of higher relief, wider and more laterally

  18. Seafloor glacial geomorphology in a cross shelf trough: insights into the deglaciation of the Melville Bay Ice Stream (United States)

    Newton, Andrew; Huuse, Mads


    Compared to other glaciated margins such as offshore mid-Norway and Svalbard, the Greenland continental shelf has, until recently, been the subject of only a limited amount of academic and industry research. This has been mainly due to the difficulty and expense of obtaining data in such harsh and operationally complex settings. Climate amelioration and technological advance has, particularly in recent years, allowed both academics and industry to substantially increase data collection across the many glaciated continental shelves in the Northern Hemisphere. Baffin Bay has been one of the primary regions of interest for the hydrocarbon industry which has sought to operate in the frontier basins offshore Greenland. As a result of these industry operations, a large database of geophysical and geological data has been collected. Some of this data has been made available to glacial scientists and provides a unique opportunity to investigate the seafloor geomorphology for regions where the majority of previous work has been hypothetical rather than grounded in geological evidence. In the work presented here we present a landform record offshore NW Greenland in the Melville Bay cross-shelf trough. This is one of the largest troughs on the entire Greenland shelf and measures up to 140 km in width. Shallow-marine cores collected in the coastal part of the trough show bedrock of Miocene age and indicate that a significant cover has likely been removed from the shelf by ice streams operating through the Late Cenozoic. This material has then been deposited at the shelf edge as a trough mouth fan. Using multibeam and seismic reflection data a large number of glacial landforms are observed and mapped in the trough. These include mega-scale glacial lineations, grounding-zone wedges, iceberg scours, and iceberg grounding pits. These landforms are used to reconstruct the ice dynamics of the Melville Bugt Ice Stream at the last glacial maximum and during its deglaciation. The

  19. Recent Contractile Deformation in the Forearc of Southern Peru: A Geomorphologic Analysis And 10Be Surface Exposure Ages (United States)

    Hall, S.; Farber, D. L.; Audin, L.; Finkel, R.


    The style, amount, and timing of deformation along the margins of the Altiplano are important components of our working model of the formation and maintenance of this high elevation plateau. While much of the convergence- related shortening is accommodated along the eastern margin in the Subandean fold and thrust belt, a significant amount of uplift and crustal thickening has occurred in the western margin during the past ~20 Myr. In addition to ancient uplift and deformation, various styles and amounts of Recent deformation that reflect the current lithospheric state of stress have been documented within the forearc. Some of the first order variables that affect the state of stress and therefore the style of deformation within the forearc of the western margin include: 1) the variable dip of the subducting slab along the South American margin, 2) the orientation of convergence relative to the margin, and 3) the subduction of aseismic ridges (e.g., Nazca Ridge). Other potential influences on the state of stress include addition of material to the western margin through lower-mid crustal flow, subduction erosion, and magmatic additions. In southern Peru, previously documented active deformation in the forearc includes coastal normal faults trending perpendicular to the trench, and transform faults oriented parallel to the trench, including the left-lateral Incapucio fault system, of the Precordillera. Our new field mapping and geochronologic studies in the Longitudinal Basin and Precordillera of southern Peru reveal recent contractile deformation along structures trending sub-parallel to the trench. Here, a southwest propagating anticline related to a blind thrust deflects the active stream channels within the Pampa Cabeza de Vaca region. Incision along the active drainages is localized to areas near active structures and has produced strath terraces that provide datable geomorphologic markers to quantify incision rates and constrain the timing of deformation

  20. Debris flow reconstruction - geomorphologic and numerical approach. A case study from the Selvetta event in Valtellina, Italy, July 2008 (United States)

    Blahut, J.; Luna, B. Quan; Akbas, S. O.; van Westen, C. J.


    On Sunday morning of 13th July 2008, after more than two days of intense rainfall, several debris and mud flows were released in the central part of Valtellina valley between Morbegno and Berbenno. One of the largest debris flows occurred in Selvetta, a fraction of Colorina municipality. The debris flow event was reconstructed after extensive field work and interviews with local inhabitants and civil protection teams. At first several rock blocks about 2 m3 in size fell down from the direction of the torrent. The blocks were followed by a wave of debris and mud that immediately destroyed one building and caused damage to other nine houses. A stream flow following the debris flow consisting of fine mud with high water content that partially washed away the accumulation of deposits from the debris phase could also be distinguished. Geomorphologic investigations allowed identification of five main sections of the flow: 1) the proper scarp; 2) path in the forested area; 3) path on the alpine meadows; 4) accelerating section; 5) accumulation area. The initiation area of the flow is situated at 1760 m. a.s.l. (1480 m above the deposition zone) in a coniferous forest. The proper scarp consisted of an area of approximately 20 m2 in size, and a height of about 0.8 m. The final volume of the debris was estimated by field mapping to be between 12 000 and 15 000 m3. It was observed that erosion and entrainment played an important role in the development of the debris flow. The Selvetta event was modelled with the FLO2D program. FLO2D is an Eulerian formulation with a finite differences numerical scheme that requires the specification of an input hydrograph. The internal stresses are isotropic and the basal shear stresses are calculated using a quadratic model. Entrainment was modeled at each section of the flow, and different hydrographs were produced in agreement with the behavior of the debris flow during its course. The significance of calculated values of pressure and

  1. Geomorphologic evolution of the eruptive vent of September 2016 at Piton de la Fournaise (La Réunion) (United States)

    Mergili, Martin; Villeneuve, Nicolas; Peltier, Aline


    The Piton de la Fournaise shield volcano on the island of La Réunion has been characterized by repeated activity since the first regular observations in the middle of the 17th century. It is shaped by a system of calderas of different ages, with the most recent one having formed in 2007 at the summit when the Cratère Dolomieu subsided by approx. 350 m within a short period of time. In the past years, activity has concentrated to several fissures and vents located along the outer slopes of the summit cone and within the surrounding caldera, Enclos Fouqué. The present contribution focuses on a geomorphologic description of the eruptive vent of the latest eruption that occurred between 11 and 18 September 2016 at Piton de la Fournaise. The course of the eruption will be illustrated through series of observations, photographs (compiled in time-lapse sequences) and geophysical data acquired by the instruments of the Volcanological Observatory (OVPF). Even though this eruption has been preceded by only a few long-term precursors, the dike propagation to the surface has been accompanied, as usual on this volcano, by a strong seismic crisis and ground deformation that lasted 56 minutes, from 03:45 to 04:41 Universal Time (UT). The beginning of the eruption has been marked by the appearance of the eruptive tremor on the seismic recordings at 04:41 UT. Ejection of lava fountains and the source of lava flows were observed on a length of approx. 1 km along the progressive opening of 7 en échelon fissures, from the northern slope of the summit cone down to the floor of the Enclos Fouqué caldera (elevation: 2340-2160 m asl). During the first hours, lava fountains were 15-30 m high. From the evening of 11 September, the fountain activity slowly confined to three (13 September) and then to two main vents (14 September) in the lower portion of the fissures. Those two vents finally coalesced on 15 September as an elongated cone where two eruptive outlets were still visible

  2. Towards realistic Holocene land cover scenarios: integration of archaeological, palynological and geomorphological records and comparison to global land cover scenarios. (United States)

    De Brue, Hanne; Verstraeten, Gert; Broothaerts, Nils; Notebaert, Bastiaan


    Accurate and spatially explicit landscape reconstructions for distinct time periods in human history are essential for the quantification of the effect of anthropogenic land cover changes on, e.g., global biogeochemical cycles, ecology, and geomorphic processes, and to improve our understanding of interaction between humans and the environment in general. A long-term perspective covering Mid and Late Holocene land use changes is recommended in this context, as it provides a baseline to evaluate human impact in more recent periods. Previous efforts to assess the evolution and intensity of agricultural land cover in past centuries or millennia have predominantly focused on palynological records. An increasing number of quantitative techniques has been developed during the last two decades to transfer palynological data to land cover estimates. However, these techniques have to deal with equifinality issues and, furthermore, do not sufficiently allow to reconstruct spatial patterns of past land cover. On the other hand, several continental and global databases of historical anthropogenic land cover changes based on estimates of global population and the required agricultural land per capita have been developed in the past decennium. However, at such long temporal and spatial scales, reconstruction of past anthropogenic land cover intensities and spatial patterns necessarily involves many uncertainties and assumptions as well. Here, we present a novel approach that combines archaeological, palynological and geomorphological data for the Dijle catchment in the central Belgium Loess Belt in order to arrive at more realistic Holocene land cover histories. Multiple land cover scenarios (> 60.000) are constructed using probabilistic rules and used as input into a sediment delivery model (WaTEM/SEDEM). Model outcomes are confronted with a detailed geomorphic dataset on Holocene sediment fluxes and with REVEALS based estimates of vegetation cover using palynological data from

  3. Analysis of topography and relief as a function of the tectonic - geomorphologic evolution of the Eastern Alps (United States)

    Bungies, Nadin; Rosenberg, Claudio


    Alpine topography and relief vary regionally (Frisch et al., 1997), even on the scale of tens of kilometers. The causes of these differences are the aim of this work that is based on a geomorphological study of the eastern Alps. Earlier investigations on the topography of the Central Alps (Rosenberg & Garcia, 2013) show, by using 50 km, 75 km, and 100 km swath profiles, that the relief northward of the Insubric Line increases westward, whereas the relief southwards of the Insubric Line decreases eastward. This trend reflects collisional shortening trends recently observed in the Central Alps (Rosenberg & Kissling, 2013). In this work, we analyse the topography of the eastern Alps from the Brenner Area in the west to the Steiermark Area in the east, based on satellite images and digital terrain models, that cover an area of 36 000 km2 in the Austrian and Italian Alps. Based on these data, new GIS-aided datasets containing selected relief factors have been derived. These data are set in relationship to the eastward decrease in collisional shortening to test whether the latter trend has a geomorphic expression. In order to assess such a relationship north-south striking profiles, subparallel to the shortening direction and in addition to an E-W profile are investigated. It can be shown that the total relief of 3100 m (500-3600 m asl.) in the west of the working area is more pronounced than the total relief of 2300 m (700-3000 m asl) in the east of the working area. Furthermore slopes have higher amplitudes in the west when compared to the east. In the west approximately 65% of the slope profile show slopes larger than 50° while in the east approximately 40% of slopes are larger than 50° (based on 30 m topographic data). The evaluation of potential influencing factors will be achieved by conducting spatial and statistical data analysis and interpretation and is complemented by local studies investigating the evolution of relief for selected geologic units. Here

  4. Geomorphological and ecological researches inferring swamp areas inside endorheic cacthment basin: The Asso graben-polje case study (south Italy). (United States)

    Delle Rose, M.; Beccarisi, L.; Zuccarello, V.


    Peoples living inside flat karstic areas frequently deal with both socio-economic and environmental problems related to the superficial waters management. Karst morphologies, such as dolines and water sinks mostly, characterize the plane territory of Salento (southern Italy). Since their first settlements, Salento landscapes had been modified to drain surface waters, discharge floods and reclaim marshlands. This contribution deals with the Asso graben-polje which is about 200 kmq wide and lies in a regional lowered tectonic structure. It is highly vulnerable owing to both flooding and groundwater pollution and the hazard due to the occurrence of sinkholes is impending. The Asso streams is network of natural and artificial channels which was linked to six water sinks about 75 years ago, i. e. during the last extensive hydrographic arrangement to solve flooding and epidemiological problems. At present, the terminal sinks of the Asso fluvial-karst system absolved the functions of: storm water drainage wells, aquifer remediation-related wells and underground injection regulated wastewater disposal systems. So, the water management of the system is an hard task, being the mitigation of the amplitude of flooding events, achieved by means of the increasing of water sinks discharge, in contrast with the safeguard aquifers by pollutant displacements and the need to protect the public health. In spite of the efforts made till now by Public Bodies, the knowledge related to the speleogenesis and the hydraulic properties of the sinks is disregarded by the current water resource management. The carried out geomorphological researches allow us to distinguish natural, partially modified and human bored water sinks. Some of the natural water sinks can be described us collapse dolines, but a number of them present different origin and development, as karst wells and karst shaft. To each water sink type, specific drainage properties can be assigned. Even if the depressions prone to

  5. Missing evidence for the LGM-asynchronity in the Central Spanish Pyrenees in geomorphological, sedimentological and pedological archives (United States)

    Hirsch, Florian; Raab, Thomas


    According to the state of knowledge, the glacial advances in the Eastern Pyrenees were synchronous with the global LGM during the Late Pleistocene (MIS 2), but the glacial advances in the Central Spanish Pyrenees at MIS 3 were asynchron with the global LGM. Whereas in the Eastern Pyrenees the glacial advances are dated in several well agreeing studies by surface exposure dating of boulders from lateral or terminal moraines, the asynchronity of the Central Spanish Pyrenees was postulated mainly by OSL dating on glacial and fluvial sediments and on radiocarbon dating of pollen from lacustrine deposits. The time difference of about 15 ka raises the question if this is a result of (local) climate factors or owed to failures caused by using several dating techniques on different archives. Anyway, if this time lag is correct, post-LGM formation of soils and sediments from the Late Pleistocene should be different between the Eastern Pyrenees and the Central Spanish Pyrenees. We therefore applied a combined approach of geomorphological, sedimentological and pedological investigations to reconstruct the Late Quaternary landscape development in the Aragon- and Gallego Valley of the Central Spanish Pyrenees. Our study reveals that in both valleys the Pre-Holocene geomorphodynamics on the lateglacial deposits show clear analogies with findings from Pleistocene periglacial landscapes in Central Europe. For MIS 4 and early MIS 3 periglacial processes are proven by loess deposition and formation of solifluction sediments. The glacial sediments, which were dated in earlier studies into mid MIS 3 and counted so far as prove for the asynchronous LGM of the Central Spanish Pyrenees, are covered by periglacial deposits of lateglacial age (14 ka to 11 ka). Surprisingly neither the glacial sediments have pedogenic features that indicate lateglacial soil development, nor do the periglacial deposits show indications for lateglacial soil erosion. Therefore we conclude that soil formation

  6. Geomorphological and geophysical investigation of a complex rock glacier system - Morenas Coloradas valley (Cordon del Plata, Mendoza, Argentina) (United States)

    Otto, Jan-Christoph; Götz, Joachim; Keuschnig, Markus; Hartmeyer, Ingo; Trombotto, Dario; Schrott, Lothar


    In the semi-arid high Andes of Argentina and Chile, rock glaciers are more frequent and often larger than glaciers. Aridity and high solar radiation hamper the development of large glaciers, favour permafrost conditions and the generation of rock glaciers. One of the few rock glaciers that have been studied in more detail since more than 20 years is located in the Cordon del Plata range about 60 km west of Mendoza, Argentina. The Morenas Coloradas rock glacier in the Rio Vallecitos catchment can be described as a multilobe, multiunit, multiroot and multipart rock glacier. It is a complex, transitional landform composed of a high altitude glaciated zone, which transforms into a debris covered glacier with thermokarst phenomena followed by various active rock glacier lobes and subsequently, inactive and relict lobes in the lower sections. Its total length is about 5 km. Complex transitional landforms between debris covered glaciers and rock glaciers are frequently observed in semi-arid mountain environments with high sediment production in periglacial areas like the Andes of Argentina but can be found also in other similar mountain ranges like for example Pamir, or Karakorum. However, the evolution and internal characteristics of such landforms are often unknown. Glacial and periglacial landforms of this size represent important water stores that play an essential role in water management and agriculture in the foreland of the Andes of Mendoza. In February 2008 subsurface conditions were investigated at three different altitudes using geophysical methods (ground penetrating radar, electric resistivity tomography). Complemented by digital geomorphological mapping we analyse the complex rock glacier ensemble, to gain insight into landform evolution, sediment flow structures and internal characteristics (permafrost occurrence, active layer depths, ice content, possible ice origin). Geophysical surveying at Morenas Coloradas clearly indicates the existence of frozen

  7. The conservation of the Shahr-e-Zohak archaeological site (central Afghanistan): Geomorphological processes and ecosystem-based mitigation (United States)

    Margottini, Claudio; Fidolini, Francesco; Iadanza, Carla; Trigila, Alessandro; Ubelmann, Yves


    The archaeological remains of Shahr-e Zohak are part of the Bamiyan valley, which has been recognized by UNESCO as World Heritage and is famous for hosting the main heritage of the Buddhist culture in Afghanistan. The site comprises the remains of the Zohak fortress, which is placed on a steep hill at the confluence of the Bamiyan and Kalu rivers. The fortress is protected by ramparts, built along the steep cliffs bounding the site, which are equipped with several watchtowers. The citadel is protected by three more orders of walls and is located on the topmost part of the hill. All the structures are made of mudbricks placed on top of stony foundations. Due to the prolonged exposure to weathering, the lack of conservation measures and the misuse during war periods, many constructions collapsed or are prone to collapse. A new topography (1 m contour lines) of the site was produced using drone-derived 3D photogrammetry combined with GPS data. Then a detailed geomorphological survey of the whole site was carried out in order to identify the main geomorphic processes acting on the land surface and structures. GIS analysis allowed defining the internal drainage system of the studied area. The site is affected by incised erosional phenomena on the eastern side, while the hilltop is mainly hit by diffuse erosion and soil mobilization during snowmelt. Monument deterioration is coupled with the lack of an adequate drainage system to collect runoff. Ramparts located on the steep hillslopes are severely affected by gully erosion and siphoning, which cause depressions infilled by eroded and weathered building material. The access path is locally eroded or buried by debris cones. The western margin of the plateau has been rapidly retreating due to collapses, while the citadel is in danger due to diffuse or gully erosional processes developed on all its sides. A mitigation strategy with low environmental impact (ecosystem-based approach) is proposed in order to adopt sustainable


    Institute of Scientific and Technical Information of China (English)


    <正>20050939 An Chengbang (Key Lab. of Western Chinese Environment System, Ministry of Education, Lanzhou University, Lanzhou, Gansu 730000, China); Feng Zhaodong Humid Climate During 9-3. 8 KaBP in the Western Part of Chinese Loess Plateau (Marine Geology & Quaternary Geology, ISSN0256-1492, CN37-1117/P, 24 (3), 2004, p. 111-116, 3 illus. , 1 table, 40 refs. , with English abstract)


    Institute of Scientific and Technical Information of China (English)


    <正>20122603 Chen Yixin ( College of Urban and Environmental Sciences,Peking University,Beijing 100871,China );Zhang Mei Fluvial Incision Process and Its Tectonic Implications of Golmud River since Last Glaciation Maximum ( Acta Geographica Sinica,ISSN0375-5444,CN11-1856 / P,66 ( 11 ), 2011,p.1540-1550,5illus.,5tables,40refs. ) Key words:river terraces,erosion surfaces,incised valleys,Qinghai Province


    Institute of Scientific and Technical Information of China (English)


    <正>20072079 Cui Zhongxie(Yanbian Seismology Bureau of Jilin Province,Yanji,Jilin 133001);Liu Jiaqi Historical Records about the Extensive Eruptions of the Tianchi Volcano in Changbai Mountains during A.D.1014~1019(Geological Review,ISSN0371-5736,CN11-1952,52(5),2006,p.624-627,13 refs.)Key words:eruptions,Changbai Mountains


    Institute of Scientific and Technical Information of China (English)


    <正>20091217 Chen Jianjun(School of Earth and Space Sciences,Peking University,Beijing 100871,China);Ji Jianqing Formation of the Yarlung Zangbo Grand Canyon,Tibet, China(Geogolical Bulletin of China,ISSN 1671-2552,CN11-4648/P,27(4),2008, p.491-499,5 illus.,2 tables,31 refs.) Key words:canyons,Yarlung Zangbo River

  12. geomorphology_delta (United States)

    California Department of Resources — Surficial geology of the Delta area of California by Brian Atwater of the U.S. Geological Survey. Source maps are from the USGS publication MF-1401. This digital...


    Institute of Scientific and Technical Information of China (English)


    20151144 Chen Jiaojie(Key Laboratory of Marine Sedimentology and Environmental Geology,No.1Institute of Oceanography,State Oceanic Administration,Qingdao 266061,China);Liu Yanguang Paleoenvironment Evolution of the Lake Khanka since the Last Gla-


    Institute of Scientific and Technical Information of China (English)


    <正>20112526Bai Daoyuan (Hunan Institute of Geology Survey,Changsha 410011,China); Liu Bo Quaternary Tectonic-Sedimentary Characteristics and Environmental Evolution of Linli Sag,Dongting Basin (Journal of


    Institute of Scientific and Technical Information of China (English)


    <正>20111129 Bai Daoyuan(Hunan Institute of Geological Survey,Changsha 410011,China);Li Chang’an Quaternary Tectonic-Sedimentary Characteristics and Environmental Evolution of Anxiang Sag in Dongting Basin and Its West Periphery(Journal of Earth Sciences and Environment,ISSN1672-6561,CN61-1423/P,32(2),2010,p.120-129,6 illus.,1 table,48 refs.)Key words:Quaternary,sedimentary environment,structural evolution,Dongtinghu Basin Detailed geologic mapping and bore data was conducted to study on the Quaternary tectonic and sedimentary characteristics and environmental evolution of Anxiang Sag and its west periphery of Dongting Basin,which provided new materials for Quaternary geology of Jianghan-Dongting Basin.The sag trends north-south direction and is surrounded by normal faults.The thickness of Quaternary deposits in the sag is commonly 100~220 m with maximun thickness of 300 m,and from lower to upper,the Quaternary strata is composed of Early Pleistocene Huatian Formation and Miluo Formation,Middle Pleistocene Dongtinghu Formation


    Institute of Scientific and Technical Information of China (English)


    20160466Cao Fugen(No.1Geological Survey Team,Xinjiang Bureau of Geology and Mineral Resources and Development,Urumqi830013,China);Zhao Shuming Geological Characteristics and Significance of the Nanhua Period Tillite from Northern Yamansu Area in Eastern Tianshan,Xinjiang(Xinjiang Geology,ISSN1000-8845,CN65-1092/P,33


    Institute of Scientific and Technical Information of China (English)


    20161195Bai Xiao(Institute of Western Environment and Climate Change,Lanzhou University,Lanzhou 730000,China);Sang Wencui Monthly Isotopic Variations of Calcite Deposition System in Wanxiang Cave,Wudu

  18. Geomorphology of Martian meanders (United States)

    Gregoire-Mazzocco, H.; Stepinski, T.; McGovern, P.; Lanzoni, S.; Marani, M.; Rinaldo, A.


    Morphological features of meandering landforms observed on the surface of Mars are computed and discussed. The relevance of the study pertains potentially useful hypotheses for the understanding of the evolution of Mars. Materials are digital images taken from the Mars Orbiter Laser Altimer (MOLA) and from the Viking orbiter. The methods of morphological analysis derive from tool employed in the analysis of channeled landforms, in particular tidal ones, where the unit of information (i.e. the elementary pixel) is considerably smaller than the size of the channels. The results obtained concern the physical characterization of martian meanders, including the evolution in space of widths, wavelengths and curvatures and their spectra. Evidence for a narrow distribution of sinuosities (possibly a proxy of age of erosion/deposition processes carving the meanders) and for tapering of widths (a proxy of landforming flowrates) appears to suggest the past existence on Mars of massive and relatively brief outbursts of flow. The range of duration of such processes might be speculated upon comparison with terrestrial processes.

  19. Sprague River Oregon Geomorphology (United States)

    U.S. Geological Survey, Department of the Interior — Geomorphic mapping establishes the basic context for understanding modern channel conditions by (1) defining major elements of the late Cenozoic geologic history...


    Institute of Scientific and Technical Information of China (English)


    <正>20141016An Chengbang(Key Laboratory of Western China’s Environmental Systems,Ministry of Education,Lanzhou University,Lanzhou 730000,China);Zhao Yongtao Lake Records during the Last Glacial Maximum from Xinjiang,NW China and Their Climatic Impli-

  1. Sea floor geomorphology: Discussion

    Digital Repository Service at National Institute of Oceanography (India)

    Evsykov, Y.D.; Murthy, K.S.R.

    stream_size 1 stream_content_type text/plain stream_name Mem_Geol_Soc_India_1998_39_38.pdf.txt stream_source_info Mem_Geol_Soc_India_1998_39_38.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

  2. Principle and geomorphological applicability of summit level and base level technique using Aster Gdem satellite-derived data and the original software Baz

    Directory of Open Access Journals (Sweden)

    Akihisa Motoki


    Full Text Available This article presents principle and geomorphological applicability of summit level technique using Aster Gdem satellite-derived topographicdata. Summit level corresponds to thevirtualtopographic surface constituted bylocalhighest points, such as peaks and plateau tops, and reconstitutes palaeo-geomorphology before the drainage erosion. Summit level map is efficient for reconstitution of palaeo-surfaces and detection of active tectonic movement. Base level is thevirtualsurface composed oflocallowest points, as valley bottoms. The difference between summit level and base level is called relief amount. Thesevirtualmapsareconstructed by theoriginalsoftwareBaz. Themacroconcavity index, MCI, is calculated from summit level and relief amount maps. The volume-normalised three-dimensional concavity index, TCI, is calculated from hypsometric diagram. The massifs with high erosive resistance tend to have convex general form and low MCI and TCI. Those with low resistance have concave form and high MCI and TCI. The diagram of TCI vs. MCI permits to distinguish erosive characteristics of massifs according to their constituent rocks. The base level map for ocean bottom detects the basement tectonic uplift which occurred before the formation of the volcanic seamounts.

  3. Identification of paleoearthquakes based on geomorphological evidence and their tectonic implications for the southern part of the active Anqiu-Juxian fault, eastern China (United States)

    Jiao, Qisong; Jiang, Wenliang; Zhang, Jingfa; Jiang, Hongbo; Luo, Yi; Wang, Xin


    This study utilized an unmanned aerial vehicle (UAV) photogrammetry system to acquire orthoimages and generate a digital elevation model (DEM) covering the southern part of the Anqiu-Juxian fault for geomorphological analysis and paleoearthquake identification. Six offset gullies were identified and analyzed on the orthoimages. Our results indicate that at least three large and several moderate earthquakes have occurred along the fault zone. Knickpoints recognized from the DEM reveal several paleoearthquakes. An average Holocene horizontal slip rate of 2.86 ± 0.35 mm yr-1 was estimated from the offset gullies, which is consistent with previous results from field surveys. The tectonic evolution of this fault zone is most likely related to subduction of the Pacific plate under the Eurasian plate, which gave rise to the right-lateral strike-slip and thrust movement of the Tan-Lu fault zone. This study provided valuable information regarding fault activity and paleoearthquake occurrence along the Anqiu-Juxian fault zone during the Holocene and demonstrated the potential of using UAVs for studies involving tectonic geomorphology.


    Directory of Open Access Journals (Sweden)

    A. J. Desai


    Full Text Available Fluvial landforms are developed due to river action and these processes help in understanding the development of various landforms on the earth's surface. Gangetic plain is vast alluvial tract made up of sand, silt and clay. This region receives heavy rainfall causing flash floods which results in bank-line shifting as well as various fluvio-geomorphological changes. Fluvial processes such as erosion and deposition not only play an important role in shaping of different fluvial landscapes but also contribute towards the braiding and meandering pattern which causes change in the flow pattern of the river channel. Transportation and deposition of the suspended load also contributes towards such changes. The present work describes various fluvio-geomorphological features and their changes during different time intervals in and around Ballia and Rudrapur. The paper also deals in understanding the problems like bank-line shifting, erosion and deposition caused by the continuous change in the fluvial patterns, bank erosion and sedimentation in this region over past 8 decades.

  5. Estimating precipitation on early Mars using a radiative-convective model of the atmosphere and comparison with inferred runoff from geomorphology

    CERN Document Server

    von Paris, P; Grenfell, J L; Hauber, E; Breuer, D; Jaumann, R; Rauer, H; Tirsch, D


    We compare estimates of atmospheric precipitation during the Martian Noachian-Hesperian boundary 3.8 Gyr ago as calculated in a radiative-convective column model of the atmosphere with runoff values estimated from a geomorphological analysis of dendritic valley network discharge rates. In the atmospheric model, we assume CO2-H2O-N2 atmospheres with surface pressures varying from 20 mb to 3 bar with input solar luminosity reduced to 75% the modern value. Results from the valley network analysis are of the order of a few mm d-1 liquid water precipitation (1.5-10.6 mm d-1, with a median of 3.1 mm d-1). Atmospheric model results are much lower, from about 0.001-1 mm d-1 of snowfall (depending on CO2 partial pressure). Hence, the atmospheric model predicts a significantly lower amount of precipitated water than estimated from the geomorphological analysis. Furthermore, global mean surface temperatures are below freezing, i.e. runoff is most likely not directly linked to precipitation. Therefore, our results strong...

  6. Climate warming and the recent treeline shift in the European alps: the role of geomorphological factors in high-altitude sites. (United States)

    Leonelli, Giovanni; Pelfini, Manuela; di Cella, Umberto Morra; Garavaglia, Valentina


    Global warming and the stronger regional temperature trends recently recorded over the European Alps have triggered several biological and physical dynamics in high-altitude environments. We defined the present treeline altitude in three valleys of a region in the western Italian Alps and reconstructed the past treeline position for the last three centuries in a nearly undisturbed site by means of a dendrochronological approach. We found that the treeline altitude in this region is mainly controlled by human impacts and geomorphological factors. The reconstruction of the altitudinal dynamics at the study site reveals that the treeline shifted upwards of 115 m over the period 1901-2000, reaching the altitude of 2505 m in 2000 and 2515 m in 2008. The recent treeline shift and the acceleration of tree colonization rates in the alpine belt can be mainly ascribed to the climatic input. However, we point out the increasing role of geomorphological factors in controlling the future treeline position and colonization patterns in high mountains.

  7. The historic landslide of Sottrù (Badia Valley, Italy) reactivated on December 13, 2012 - a geomorphological interpretation (United States)

    Ghinoi, Alessandro; Soldati, Mauro; Freddi, Raffaele; Pasuto, Alessandro


    On 13 December 2012, after a long period of dormancy, the historic landslide of Sottrù, located in the Badia Valley (Autonomous Province of Bolzano, Italy), was reactivated, destroying a few houses and almost damming the Gadera torrent. According to historic documents, the previous activation dates back to June 1821. At that time, the slope was mobilized after a period of persistent rain and snow melt, causing the damming of the Gadera torrent. After snow melting, in June 1827 the natural dam collapsed, flooding meadows and villages down valley. In December 2012, the landslide was partly reactivated, showing the first slow movements on the 13th and more rapid displacements on the 14th. A detailed geomorphological survey of the landslide was carried out during summer 2014, aiming at identifying the instability causes, mapping the landslide in detail and investigating the hydrological and hydrogeological characteristics of the slope. A surficial highly permeable level (in-situ or reworked till) was found lying on top of a thick sequence of clays, shales, sandstones and marls, both over the landslide body and the surrounding areas. The permeability contrast existing between the till and the bedrock is thought to extend to larger portions of the slopes of the Gadera valley and it could reasonably be considered as one of the main predisposing factors for the onset of the several landslides that characterize the area. From the landslide scar uphill, the hydrographic pattern is extremely irregular, made of discontinuous drainage lines indicative of higher infiltration rate than superficial run off. The comparison between the current morphology and the pre-2012 one has not evidenced any movement within the historic source area, while relevant displacements occurred at two lateral zones and at the central part of the landslide, originating a second, lower crown. Since the previous activation (1821), the landslide has been dormant for 191 years, and the 2012 event occurred

  8. Geomorphology, facies architecture, and high-resolution, non-marine sequence stratigraphy in avulsion deposits, Cumberland Marshes, Saskatchewan (United States)

    Farrell, K. M.


    proposed by Smith et al. (Sedimentology, vol. 36 (1989) 1) is revised to include facies and geometries consistent with a bayfill model. By analogy with delta lobes, the avulsion sequence is a parasequence, provided that its definition is modified to be independent from sea level. In non-marine settings, facies contacts at the tops of regional peats, coals, and paleosols are analogous to marine flooding surfaces. A parasequence is redefined here as a relatively conformable succession of genetically related strata or landforms that is bounded by regional flooding surfaces or their correlative surfaces. This broader definition incorporates the concept of landscape evolution between regional flooding surfaces in a variety of depositional settings. With respect to landscape evolution, accommodation space has three spatial dimensions — vertical ( x), lateral ( y), and down-the-basin ( z). A flood basin fills in as landforms vertically ( x) and laterally accrete ( y), and prograde down-the-basin ( z). Vertical aggradation is limited by the elevation of maximum flood stage (local base level). Differential tectonism and geomorphology control the slope of the flood basin floor and the direction of landscape evolution. These processes produce parasequences that include inclined stratal surfaces and oriented, stacked macroforms (clinoforms) that show the magnitude and direction of landscape evolution.

  9. Fossil debris-covered glaciers in Demanda Sierra (Northern Spain): geomorphological research and 10Be cosmogenic exposure dating (United States)

    Fernández-Fernández, José M.; Palacios, David; Andrés, Nuria; Schimmelpfennig, Irene; Gómez-Villar, Amelia; Santos-González, Javier; Álvarez-Martínez, Javier; Arnáez, José; Úbeda, José; García-Ruiz, José M.


    The Demanda Sierra, at altitudes above 2000 m.a.s.l., is located in the Iberian Range (Northern Iberian Peninsula, 42°15' N). The main divide extends from west to east between 3°25' W and 2°52' W. The most relevant evidences of Pleistocene glaciation are found in small cirques above 1800 m a.s.l., most of them in the northern face. These cirques hosted small-size glaciers with ice tongues fossil debris-covered glaciers. To elucidate such a complex issue, two north-facing cirques in the Mencilla Peak (42°11'11" N, 3°18'45" W; 1932 m a.s.l.) and a southeast-facing cirque in the San Lorenzo Peak (42°14'28" N, 2°58'31" W; 2261 m a.s.l.) have been selected as they host similar block accumulations. The aim of this paper is: 1) to identify the debris-covered glacier features in such block accumulations; 2) to present the chronology obtained for the first time from debris-covered glaciers and to put them in the context of deglaciation in the Iberian Range and in the Iberian Peninsula and the Mediterranean mountains; 3) to analyze the glacier evolution during the deglaciation. To carry out these objectives, different methodological approaches and techniques have been applied: 1) detailed geomorphological mapping at 1:1000 scale over stereoscopic pairs, high-resolution LIDAR Digital Elevation Models and fieldwork to identify glacial and debris-covered glacier features (e.g. moraines, ridges, furrows, etc.); 2) Cosmogenic Exposure Dating (CED), 10Be, applied to 18 quartzite samples taken from stable boulders over moraine ridges or fossil debris-covered glaciers; 3) glacier reconstruction for modelling the glacier evolution at different stages; 4) Equilibrium Line Altitude (ELA) calculation. The results obtained show that the large chaotic block accumulations are fossil debris-covered glaciers given the numerous longitudinal ridges and furrows. These fossil debris-covered glaciers consist of a relatively thin debris mantle (<2 m thick), deposited over the residual ice

  10. An Assessment of Hydrology, Fluvial Geomorphology, and Stream Ecology in the Cardwell Branch Watershed, Nebraska, 2003-04 (United States)

    Rus, David L.; Dietsch, Benjamin J.; Woodward, Brenda K.; Fry, Beth E.; Wilson, Richard C.


    An assessment of the 16.3-square-mile Cardwell Branch watershed characterized the hydrology, fluvial geomorphology, and stream ecology in 2003-04. The study - performed by the U.S. Geological Survey in cooperation with the City of Lincoln, Nebraska, and the Lower Platte South Natural Resources District - focused on the 7.7-square-mile drainage downstream from Yankee Hill Reservoir. Hydrologic and hydraulic models were developed using the Hydrologic Modeling System (HEC-HMS) and River Analysis System (HEC-RAS) of the U.S. Army Corps of Engineers Hydraulic Engineering Center. Estimates of streamflow and water-surface elevation were simulated for 24-hour-duration design rainstorms ranging from a 50-percent frequency to a 0.2-percent frequency. An initial HEC-HMS model was developed using the standardized parameter estimation techniques associated with the Soil Conservation Service curve number technique. An adjusted HEC-HMS model also was developed in which parameters were adjusted in order for the model output to better correspond to peak streamflows estimated from regional regression equations. Comparisons of peak streamflow from the two HEC-HMS models indicate that the initial HEC-HMS model may better agree with the regional regression equations for higher frequency storms, and the adjusted HEC-HMS model may perform more closely to regional regression equations for larger, rarer events. However, a lack of observed streamflow data, coupled with conflicting results from regional regression equations and local high-water marks, introduced considerable uncertainty into the model simulations. Using the HEC-RAS model to estimate water-surface elevations associated with the peak streamflow, the adjusted HEC-HMS model produced average increases in water-surface elevation of 0.2, 1.1, and 1.4 feet for the 50-, 1-, and 0.2-percent-frequency rainstorms, respectively, when compared to the initial HEC-HMS model. Cross-sectional surveys and field assessments conducted between

  11. Learning from Nature - Mapping of Complex Hydrological and Geomorphological Process Systems for More Realistic Modelling of Hazard-related Maps (United States)

    Chifflard, Peter; Tilch, Nils


    Introduction Hydrological or geomorphological processes in nature are often very diverse and complex. This is partly due to the regional characteristics which vary over time and space, as well as changeable process-initiating and -controlling factors. Despite being aware of this complexity, such aspects are usually neglected in the modelling of hazard-related maps due to several reasons. But particularly when it comes to creating more realistic maps, this would be an essential component to consider. The first important step towards solving this problem would be to collect data relating to regional conditions which vary over time and geographical location, along with indicators of complex processes. Data should be acquired promptly during and after events, and subsequently digitally combined and analysed. Study area In June 2009, considerable damage occurred in the residential area of Klingfurth (Lower Austria) as a result of great pre-event wetness and repeatedly heavy rainfall, leading to flooding, debris flow deposit and gravitational mass movement. One of the causes is the fact that the meso-scale watershed (16 km²) of the Klingfurth stream is characterised by adverse geological and hydrological conditions. Additionally, the river system network with its discharge concentration within the residential zone contributes considerably to flooding, particularly during excessive rainfall across the entire region, as the flood peaks from different parts of the catchment area are superposed. First results of mapping Hydro(geo)logical surveys across the entire catchment area have shown that - over 600 gravitational mass movements of various type and stage have occurred. 516 of those have acted as a bed load source, while 325 mass movements had not reached the final stage yet and could thus supply bed load in the future. It should be noted that large mass movements in the initial or intermediate stage were predominately found in clayey-silty areas and weathered material

  12. Submarine geomorphology of the Celtic Sea - new observations and hypotheses for the glaciation of a mid-latitude continental shelf (United States)

    Praeg, Daniel; McCarron, Stephen; Dove, Dayton; Cofaigh, Colm Ó.; Monteys, Xavier; Coxon, Peter; Accettella, Daniella; Cova, Andrea; Facchin, Lorenzo; Romeo, Roberto; Scott, Gill


    The southern limit of glaciation of the European continental margin lies in the Celtic Sea, where the full extent and dynamics of the British-Irish Ice Sheet (BIIS) remain in question. This is in part because the broad continental shelf contains no obvious glacial geomorphological features, but is dominated by a system of shelf-crossing sediment ridges, up to 60 m high, 10 km wide and 300 km long, traditionally interpreted as moribund palaeo-tidal sand banks. Ice sheet extent has been constrained by samples of subglacial and glacimarine sediments recovered (in the 1970s) between the ridges, and in places on their flanks, used to propose a tidewater ice margin that advanced to a grounding line on the mid-shelf, overriding a precursor ridge system. New information on the glaciation of the Celtic Sea is available from geophysical and core data acquired during Italian- and Irish-led campaigns in 2009, 2012, and 2014, both from the mid- and outer shelf. On the mid-shelf, multibeam seabed imagery of a 25 x 100 km area reveal a distinctive rectilinear network of en echelon ridge segments giving way laterally and longitudinally to transverse ribs. Seismic correlation to glacigenic sediments previously cored on a ridge flank (at core site 49/-09/44) indicates the ribs to be composed in part of glacimarine sediments, above a till reflection that can be traced across the ridge crest. No change in seabed morphology is observed across the proposed grounding line. On the outer shelf, new cores of glacigenic sediments were obtained from the flank of a shelf-crossing ridge, and provide evidence of ice sheet advance to the shelf edge, 150 km beyond the proposed grounding line. The cores from outer Cockburn Bank contain facies interpreted to record subglacial deformation and glacimarine deposition from turbid meltwater plumes during withdrawal of a tidewater ice sheet margin from the shelf edge by 24,265 ± 195 cal BP. These sediments are inferred to form part of a sheet of

  13. Insights from a Geophysical and Geomorphological Mars Analog Field Study at the Great Kobuk Sand Dunes, Northwestern Alaska (United States)

    McGinnis, R. N.; Dinwiddie, C. L