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Sample records for complex geomorphological river

  1. Geomorphology and River Management

    Directory of Open Access Journals (Sweden)

    GARY BRIERLEY

    2008-01-01

    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.

  2. Toward a new system approach of complexity in geomorphology

    Science.gov (United States)

    Masson, E.

    2012-04-01

    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

  3. Geomorphology

    Science.gov (United States)

    1982-01-01

    The study of geomorphology and terrain analysis using TM and MSS data are discussed. The spatial and spectral characteristics of a variety of landforms are also investigated. An outline of possible experiments and a summary of data requirements are included.

  4. Geomorphological change and river rehabilitation : case studies on lowland fluvial ystems in the Netherlands

    NARCIS (Netherlands)

    Wolfert, Hendrik Pieter

    2001-01-01

    Integrated spatial planning for river rehabilitation requires insight in the geomorphology of river systems. Procedures are elaborated to implement a functional-geographical approach in geomorphology, in which a view of rivers as four-dimensional systems and the use of a process-based hierarchy of

  5. Fluvial hydrology and geomorphology of Monsoon-dominated Indian rivers

    Directory of Open Access Journals (Sweden)

    Vishwas S. Kale

    2005-11-01

    Full Text Available The Indian rivers are dominantly monsoon rainfed. As a result, their regime characteristics are dictated by the spatio-temporal variations in the monsoon rainfall. Although the rivers carry out most of the geomorphic work during 4-5 months of the monsoon season, the nature and magnitude of response to variations in the discharge and sediment load varies with the basin size and relief characteristics. Large monsoon floods play a role of great importance on all the rivers. This paper describes the hydrological and geomorphological characteristics of the two major fluvial systems of the Indian region, namely the Himalayan fluvial system and the Peninsular fluvial system. Large number of studies published so far indicate that there are noteworthy differences between the two river systems, with respect to river hydrology, channel morphology, sediment load and behaviour. The nature of alterations in the fluvial system due to increased human interference is also briefly mentioned. This short review demonstrates that there is immense variety of rivers in India. This makes India one of the best places to study rivers and their forms and processes.

  6. A geomorphological characterisation of river systems in South Africa: A case study of the Sabie River

    Science.gov (United States)

    Eze, Peter N.; Knight, Jasper

    2018-06-01

    Fluvial geomorphology affects river character, behaviour, evolution, trajectory of change and recovery potential, and as such affects biophysical interactions within a catchment. Water bodies in South Africa, in common with many other water-stressed parts of the world, are generally under threat due to increasing natural and anthropogenic influences including aridity, siltation and pollution, as well as climate and environmental change. This study reports on a case study to characterise the geomorphology of different river systems in South Africa, with the aim of better understanding their properties, controls, and implications for biophysical interactions including water quality, biodiversity (aquatic and riparian), and human activity within the catchment. The approach adopted is based on the River Styles® framework (RSF), a geomorphology-based approach developed for rivers in New Zealand and Australia, but applied here for the first time to South Africa. Based on analysis of remote sensing imagery, SRTM-2 digital topographic data and field observations on sites through the entire river system, six geomorphic elements were identified along the Sabie River, northeast South Africa (gorge, bedrock-forced meander, low-moderate sinuosity planform controlled sand bed, meandering sand bed, low sinuosity fine grained sand bed, and floodouts), using the RSF classification scheme and based on the RSF procedural tree of Brierley and Fryirs (2005). Previous geomorphological studies along the Sabie River have shown that different reaches respond differently to episodic floods; we use these data to link river geomorphological character (as defined by the RSF) to the hydrodynamic conditions and processes giving rise to such character. This RSF approach can be used to develop a new management approach for river systems that considers their functional biophysical behaviour within individual reaches, rather than considering them as homogeneous and uniform systems.

  7. Geomorphology and river dynamics of the lower Copper River, Alaska

    Science.gov (United States)

    Brabets, Timothy P.; Conaway, Jeffrey S.

    2009-01-01

    Located in south-central Alaska, the Copper River drains an area of more than 24,000 square miles. The average annual flow of the river near its mouth is 63,600 cubic feet per second, but is highly variable between winter and summer. In the winter, flow averages approximately 11,700 cubic feet per second, and in the summer, due to snowmelt, rainfall, and glacial melt, flow averages approximately 113,000 cubic feet per second, an order of magnitude higher. About 15 miles upstream of its mouth, the Copper River flows past the face of Childs Glacier and enters a large, broad, delta. The Copper River Highway traverses this flood plain, and in 2008, 11 bridges were located along this section of the highway. The bridges cross several parts of the Copper River and in recent years, the changing course of the river has seriously damaged some of the bridges.Analysis of aerial photography from 1991, 1996, 2002, 2006, and 2007 indicates the eastward migration of a channel of the Copper River that has resulted in damage to the Copper River Highway near Mile 43.5. Migration of another channel in the flood plain has resulted in damage to the approach of Bridge 339. As a verification of channel change, flow measurements were made at bridges along the Copper River Highway in 2005–07. Analysis of the flow measurements indicate that the total flow of the Copper River has shifted from approximately 50 percent passing through the bridges at Mile 27, near the western edge of the flood plain, and 50 percent passing through the bridges at Mile 36–37 to approximately 5 percent passing through the bridges at Mile 27 and 95 percent through the bridges at Mile 36–37 during average flow periods.The U.S. Geological Survey’s Multi-Dimensional Surface-Water Modeling System was used to simulate water-surface elevation and velocity, and to compute bed shear stress at two areas where the Copper River is affecting the Copper River Highway. After calibration, the model was used to examine the

  8. The igapó of the Negro River in central Amazonia: Linking late-successional inundation forest with fluvial geomorphology

    Science.gov (United States)

    Montero, Juan Carlos; Latrubesse, Edgardo M.

    2013-10-01

    Despite important progress on Amazonian floodplain research, the flooded forest of the Negro River "igapó" has been little investigated. In particular, no study has previously focused the linkage between fluvial geomorphology and the floristic variation across the course of the river. In this paper we describe and interpret relations between igapó forest, fluvial geomorphology and the spatial evolution of the igapó forest through the Holocene. Therefore, we investigate the effect of geomorphological units of the floodplain and channel patterns on tree diversity, composition and structural parameters of the late-successional igapó forest. Our results show that sites sharing almost identical flooding regime, exhibit variable tree assemblages, species richness and structural parameters such as basal area, tree density and tree heights, indicating a trend in which the geomorphologic styles seem to partially control the organization of igapó's tree communities. This can be also explained by the high variability of well-developed geomorphologic units in short distances and concentrated in small areas. In this dynamic the inputs from the species pool of tributary rivers play a crucial role, but also the depositional and erosional processes associated with the evolution of the floodplain during the Holocene may control floristic and structural components of the igapó forests. These results suggest that a comprehensive approach integrating floristic and geomorphologic methods is needed to understand the distribution of the complex vegetation patterns in complex floodplains such as the igapó of the Negro River. This combination of approaches may introduce a better comprehension of the temporal and spatial evolutionary analysis and a logic rationale to understand the vegetation distribution and variability in function of major landforms, soil distributions and hydrology. Thus, by integrating the past into macroecological analyses will sharpen our understanding of the

  9. Geomorphology of the Trinity River floodplain in Dallas County, Texas

    Science.gov (United States)

    Haugen, B. D.; Roig-Silva, C.; Manning, A. R.; Harrelson, D. W.; Olsen, R. S.; Dunbar, J. P.; Pearson, M. L.

    2010-12-01

    Data from more than 1,800 geologic borings and over 500 cone penetrometer tests (CPTs) were used to characterize the geomorphology of the Trinity River floodplain in the Dallas Metropolitan Area. Historical maps, aerial photographs and other published information were used to prepare a preliminary geomorphic map. Boring logs and CPT data were then used to refine the preliminary map, produce a series of two-dimensional (2D) and three-dimensional (3D) cross sections, and interpret the recent geologic history of the area. Geomorphologic interpretations - most importantly the locations of paleo-channel deposits of sands and gravels - were used to identify reaches of the levees managed by the United States Army Corps of Engineers (USACE) and the City of Dallas that may be at significant risk for under-seepage. Boring logs and CPT data collected atop the levees were used to assess through-seepage risks. Local bedrock is comprised of cretaceous-age Eagle Ford Shale and Austin Chalk. Depth to bedrock in the study area averaged 14.6 m (47.8 ft). The uppermost surface of bedrock has been deeply incised by a meandering river. Vertical relief between the shallowest bedrock sections and deepest portion of the incised paleo-channel is more than 15 m (50 ft). In places the incised paleo-channel is more than 0.8 km (0.5 mi) wide. These data confirm the presence of an erosional unconformity between local bedrock and overlying quaternary floodplain deposits. The observed erosional unconformity is attributed to a higher-energy fluvial environment that occurred as a result of a drop in base level. Recent floodplain deposits consist of interlobate point bar, channel and overbank sediments that are generally distributed in a fining-upward sequence. Buried channel dimensions vary widely, but are more than 250 m (820 ft) in some areas - much larger than the current channel. A semi-continuous basal layer of quaternary sands and gravels approximately 2 to 5 m (7 to 16 ft) thick exists in

  10. Geology and geomorphology of the Lower Deschutes River Canyon, Oregon.

    Science.gov (United States)

    Robin A. Beebee; Jim E. O' Connor; Gordon E. Grant

    2002-01-01

    This field guide is designed for geologists floating the approximately 80 kilometers (50 miles) of the Deschutes River from the Pelton-Round Butte Dam Complex west of Madras to Maupin, Oregon. The first section of the guide is a geologic timeline tracing the formation of the units that compose the canyon walls and the incision of the present canyon. The second section...

  11. Hydro-geomorphological characterization and classification of Chilean river networks using horizontal, vertical and climatological properties

    Science.gov (United States)

    Pereira, A. A.; Gironas, J. A.; Passalacqua, P.; Mejia, A.; Niemann, J. D.

    2017-12-01

    Previous work has shown that lithological, tectonic and climatic processes have a major influence in shaping the geomorphology of river networks. Accordingly, quantitative classification methods have been developed to identify and characterize network types (dendritic, parallel, pinnate, rectangular and trellis) based solely on the self-affinity of their planform properties, computed from available Digital Elevation Model (DEM) data. In contrast, this research aim is to include both horizontal and vertical properties to evaluate a quantitative classification method for river networks. We include vertical properties to consider the unique surficial conditions (e.g., large and steep height drops, volcanic activity, and complexity of stream networks) of the Andes Mountains. Furthermore, the goal of the research is also to explain the implications and possible relations between the hydro-geomorphological properties and climatic conditions. The classification method is applied to 42 basins in the southern Andes in Chile, ranging in size from 208 Km2 to 8,000 Km2. The planform metrics include the incremental drainage area, stream course irregularity and junction angles, while the vertical metrics include the hypsometric curve and the slope-area relationship. We introduce new network structures (Brush, Funnel and Low Sinuosity Rectangular), possibly unique to the Andes, that can be quantitatively differentiated from previous networks identified in other geographic regions. Then, this research evaluates the effect that excluding different Strahler order streams has on the horizontal properties and therefore in the classification. We found that climatic conditions are not only linked to horizontal parameters, but also to vertical ones, finding significant correlation between climatic variables (average near-surface temperature and rainfall) and vertical measures (parameters associated with the hypsometric curve and slope-area relation). The proposed classification shows

  12. Yangon River Geomorphology Identification and its Enviromental Imapacts Analsysi by Optical and Radar Sensing Techniques

    Science.gov (United States)

    Lwin, A.; Khaing, M. M.

    2012-07-01

    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.

  13. Alligator Rivers Analogue project. Geomorphology and paleoclimatic history

    International Nuclear Information System (INIS)

    Wyrwoll, K.H.

    1992-01-01

    The aim of this volume is to discuss the likely influence of geomorphological and palaeoclimatic controls on the development of the secondary dispersion fan at Koongarra. For the Koongarra area the Phanerozoic was a time of tectonic stability and predominantly subaerial denudation. The structural geology of the region facilitated the erosion of the Kombolgie Formation, setting in train the development of Koongarra Valley. With the removal of the Kombolgie cover the surface of the Cahill Formation could then be eroded. The geochemical controls on the development of the secondary dispersion fan require the orebody to be located in an oxidising weathering environment. Under the present weathering regimes it seems that this implies that the orebody is located at a depth of less than 30 m. From estimates of the present regional denudation rates of the area and wider geomorphological considerations, it is concluded that the top of the orebody would have reached such a depth at some time in the last 1-6 million years. The climates of the Late Quaternary provide some guide to Pleistocene climatic events. The most intense aridity coincided with times of global glacial maxima. There is also evidence that in the Late Cenozoic there were times of elevated rates of chemical weathering. However, the timing, nature and duration of such events is unclear. 171 refs., 4 tabs., 35 refs

  14. Fluvial geomorphology and river engineering: future roles utilizing a fluvial hydrosystems framework

    Science.gov (United States)

    Gilvear, David J.

    1999-12-01

    River engineering is coming under increasing public scrutiny given failures to prevent flood hazards and economic and environmental concerns. This paper reviews the contribution that fluvial geomorphology can make in the future to river engineering. In particular, it highlights the need for fluvial geomorphology to be an integral part in engineering projects, that is, to be integral to the planning, implementation, and post-project appraisal stages of engineering projects. It should be proactive rather than reactive. Areas in which geomorphologists will increasingly be able to complement engineers in river management include risk and environmental impact assessment, floodplain planning, river audits, determination of instream flow needs, river restoration, and design of ecologically acceptable channels and structures. There are four key contributions that fluvial geomorphology can make to the engineering profession with regard to river and floodplain management: to promote recognition of lateral, vertical, and downstream connectivity in the fluvial system and the inter-relationships between river planform, profile, and cross-section; to stress the importance of understanding fluvial history and chronology over a range of time scales, and recognizing the significance of both palaeo and active landforms and deposits as indicators of levels of landscape stability; to highlight the sensitivity of geomorphic systems to environmental disturbances and change, especially when close to geomorphic thresholds, and the dynamics of the natural systems; and to demonstrate the importance of landforms and processes in controlling and defining fluvial biotopes and to thus promote ecologically acceptable engineering. Challenges facing fluvial geomorphology include: gaining full acceptance by the engineering profession; widespread utilization of new technologies including GPS, GIS, image analysis of satellite and airborne remote sensing data, computer-based hydraulic modeling and

  15. Geology and geomorphology of Bear Lake Valley and upper Bear River, Utah and Idaho

    Science.gov (United States)

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

    2009-01-01

    Bear Lake, on the Idaho-Utah border, lies in a fault-bounded valley through which the Bear River flows en route to the Great Salt Lake. Surficial deposits in the Bear Lake drainage basin provide a geologic context for interpretation of cores from Bear Lake deposits. In addition to groundwater discharge, Bear Lake received water and sediment from its own small drainage basin and sometimes from the Bear River and its glaciated headwaters. The lake basin interacts with the river in complex ways that are modulated by climatically induced lake-level changes, by the distribution of active Quaternary faults, and by the migration of the river across its fluvial fan north of the present lake. The upper Bear River flows northward for ???150 km from its headwaters in the northwestern Uinta Mountains, generally following the strike of regional Laramide and late Cenozoic structures. These structures likely also control the flow paths of groundwater that feeds Bear Lake, and groundwater-fed streams are the largest source of water when the lake is isolated from the Bear River. The present configuration of the Bear River with respect to Bear Lake Valley may not have been established until the late Pliocene. The absence of Uinta Range-derived quartzites in fluvial gravel on the crest of the Bear Lake Plateau east of Bear Lake suggests that the present headwaters were not part of the drainage basin in the late Tertiary. Newly mapped glacial deposits in the Bear River Range west of Bear Lake indicate several advances of valley glaciers that were probably coeval with glaciations in the Uinta Mountains. Much of the meltwater from these glaciers may have reached Bear Lake via groundwater pathways through infiltration in the karst terrain of the Bear River Range. At times during the Pleistocene, the Bear River flowed into Bear Lake and water level rose to the valley threshold at Nounan narrows. This threshold has been modified by aggradation, downcutting, and tectonics. Maximum lake

  16. Fluvial Geomorphology and River Restoration: Uneasy Allies (Invited)

    Science.gov (United States)

    Kondolf, G. M.

    2009-12-01

    A growing body of literature demonstrates that river restoration based on understanding of geomorphic and ecological process is more likely to be sustainable than form-based approaches. In the early days of river ‘restoration’ in North America, most projects involved bank stabilization, habitat structure placement, or construction of rocked meandering channels, at odds with restoration of the dynamic processes we now see as fundamental to effective, sustainable restoration. Recent years have seen a growing body of restoration programs emphasizing restoration of connectivity and geomorphic process. This evolution has been reflected in publications, from the form-based approach advocated in the early 1990s by an NRC panel (which did not include a geomorphologist) to more recent works by interdisciplinary panels emphasizing process restoration. Large-scale river restoration came later to Europe, motivated by the EU Water Framework Directive (2000) requirements that member states implement measures to improve ecological status of degraded rivers. Interestingly, European approaches to restoration have often reflected a more nuanced understanding of process, including deliberate recreation of unstable braided channels, removal of bank protection, and reconnecting floodplains. In part this may reflect a reaction to the more thorough post-war channelization of rivers in western Europe. In part it may also reflect a greater influence of academic and research laboratories upon practitioners than in the US, where a strong anti-intellectual strain, cultural preference for easy fixes, and reluctance to conduct objective post-project assessments have contributed to the adoption of form-based approaches by many public agencies.

  17. Applying fluvial geomorphology to river channel management: Background for progress towards a palaeohydrology protocol

    Science.gov (United States)

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

    2008-06-01

    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.

  18. Capability of applying morphometric parameters of relief in river basins for geomorphological zoning of a territory

    Science.gov (United States)

    Ivanov, M. A.; Yermolaev, O. P.

    2018-01-01

    Information about morphometric characteristics of relief is necessary for researches devoted to geographic characteristics of territory, its zoning, assessment of erosion processes, geoecological condition and others. For the Volga Federal District for the first time a spatial database of geomorphometric parameters 1: 200 000 scale was created, based on a river basin approach. Watersheds are used as a spatial units created by semi-automated method using the terrain and hydrological modeling techniques implemented in the TAS GIS and WhiteBox GIS. As input data DEMs SRTM and Aster GDEM and hydrographic network vectorized from topographic maps were used. Using DEM highlighted above for each river basin, basic morphometric relief characteristics such as mean height, slope steepness, slope length, height range, river network density and factor LS were calculated. Basins belonging to the geomorphological regions and landscape zones was determined, according to the map of geomorphological zoning and landscape map. Analysis of variance revealed a statistically significant relationship between these characteristics and geomorphological regions and landscape zones. Consequently, spatial trends of changes of analyzed morphometric characteristics were revealed.

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

    Science.gov (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.

    2012-04-01

    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

  20. Geomorphological evidences of Quaternary tectonic activities in the Santa Cruz river valley, Patagonia, Argentina

    International Nuclear Information System (INIS)

    Massabie, A.; Sanguinetti, A.; Nestiero, O.

    2007-01-01

    From Argentin lake, at west on Andean hills, to Puerto Santa Cruz on Atlantic coast, Santa Cruz river cross eastward Santa Cruz province over 250 km in Patagonia at southern Argentina. Present bed of the river has a meandering outline with first order meanders of great ratio bends and second order meanders of minor ratio bends. Principal wanderings are 45 to 55 km spaced from near Estancia La Julia or Rio Bote at west to Comandante Luis Piedrabuena at east. On river's bed middle sector these great curvatures are located at Estancia Condor Cliff and Estancia Rincon Grande. Regional and partial detailed studies allow to recognize structural control on river's bed sketch and valley s geomorphology that relates first order bends with reactivated principal faults. These faults fit well with parallel system of northwest strike of Austral Basin.On geological, geomorphologic and structural evidences recognized in Santa Cruz river, quaternary tectonic activity, related to Andean movements in southern Patagonian foreland, is postulated. (author)

  1. Studies on geo-morphology, ecology and fish production of the 92 rivers of Rajshahi Division, Bangladesh

    OpenAIRE

    Rahman, M.K.; Akhter, J.N.; Nima, A.; Ahmed, S.U.; Mazid, M.A.

    2003-01-01

    Geo-morphology, ecology and fish production of the 92 rivers of Rajshahi division have been presented in this paper. Fifteen rivers are dead and 11 rivers have severe erosion problem. Siltation has increased in 66 rivers and depth has decreased in 11 rivers. Sixty nine rivers are suffering from low flow conditions. Fish diversity has decreased in 20 rivers while fish production has declined in 75 rivers. A total of 31 fish species have extinct, 25 species are under threat of extinction and 43...

  2. The Potential for Dams to Impact Lowland Meandering River Floodplain Geomorphology

    Directory of Open Access Journals (Sweden)

    Philip M. Marren

    2014-01-01

    Full Text Available The majority of the world's floodplains are dammed. Although some implications of dams for riverine ecology and for river channel morphology are well understood, there is less research on the impacts of dams on floodplain geomorphology. We review studies from dammed and undammed rivers and include influences on vertical and lateral accretion, meander migration and cutoff formation, avulsion, and interactions with floodplain vegetation. The results are synthesized into a conceptual model of the effects of dams on the major geomorphic influences on floodplain development. This model is used to assess the likely consequences of eight dam and flow regulation scenarios for floodplain geomorphology. Sediment starvation downstream of dams has perhaps the greatest potential to impact on floodplain development. Such effects will persist further downstream where tributary sediment inputs are relatively low and there is minimal buffering by alluvial sediment stores. We can identify several ways in which floodplains might potentially be affected by dams, with varying degrees of confidence, including a distinction between passive impacts (floodplain disconnection and active impacts (changes in geomorphological processes and functioning. These active processes are likely to have more serious implications for floodplain function and emphasize both the need for future research and the need for an “environmental sediment regime” to operate alongside environmental flows.

  3. The potential for dams to impact lowland meandering river floodplain geomorphology.

    Science.gov (United States)

    Marren, Philip M; Grove, James R; Webb, J Angus; Stewardson, Michael J

    2014-01-01

    The majority of the world's floodplains are dammed. Although some implications of dams for riverine ecology and for river channel morphology are well understood, there is less research on the impacts of dams on floodplain geomorphology. We review studies from dammed and undammed rivers and include influences on vertical and lateral accretion, meander migration and cutoff formation, avulsion, and interactions with floodplain vegetation. The results are synthesized into a conceptual model of the effects of dams on the major geomorphic influences on floodplain development. This model is used to assess the likely consequences of eight dam and flow regulation scenarios for floodplain geomorphology. Sediment starvation downstream of dams has perhaps the greatest potential to impact on floodplain development. Such effects will persist further downstream where tributary sediment inputs are relatively low and there is minimal buffering by alluvial sediment stores. We can identify several ways in which floodplains might potentially be affected by dams, with varying degrees of confidence, including a distinction between passive impacts (floodplain disconnection) and active impacts (changes in geomorphological processes and functioning). These active processes are likely to have more serious implications for floodplain function and emphasize both the need for future research and the need for an "environmental sediment regime" to operate alongside environmental flows.

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

    Directory of Open Access Journals (Sweden)

    Vishnyakov Nikolay Vladimirovich

    2014-12-01

    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.

  5. Geomorphology-based interpretation of sedimentation rates from radiodating, lower Passaic River, New Jersey, USA.

    Science.gov (United States)

    Erickson, Michael J; Barnes, Charles R; Henderson, Matthew R; Romagnoli, Robert; Firstenberg, Clifford E

    2007-04-01

    Analysis of site geomorphology and sedimentation rates as an indicator of long-term bed stability is central to the evaluation of remedial alternatives for depositional aquatic environments. In conjunction with various investigations of contaminant distribution, sediment dynamics, and bed stability in the Passaic River Estuary, 121 sediment cores were collected in the early 1990s from the lower 9.7 km of the Passaic River and analyzed for lead-210 (210Pb), cesium-137 (137Cs), and other analytes. This paper opportunistically uses the extensive radiochemical dataset to examine the spatial patterns of long-term sedimentation rates in, and associated geomorphic aspects of, this area of the river. For the purposes of computing sedimentation rates, the utility of the 210Pb and 137Cs depositional profiles was assessed to inform appropriate interpretation. Sedimentation rates were computed for 90 datable cores by 3 different methods, depending on profile utility. A sedimentation rate of 0 was assigned to 17 additional cores that were not datable and for which evidence of no deposition exists. Sedimentation patterns were assessed by grouping results within similar geomorphic areas, delineated through inspection of bathymetric data. On the basis of channel morphology, results reflect expected patterns, with the highest sedimentation rates observed along point bars and channel margins. The lowest rates of sedimentation (and the largest percentage of undatable cores) were observed in the areas along the outer banks of channel bends. Increasing sedimentation rates from upstream to downstream were noted. Average and median sedimentation rates were estimated to be 3.8 and 3.7 cm/y, respectively, reflecting the highly depositional nature of the Passaic River estuary. This finding is consistent with published descriptions of long-term geomorphology for Atlantic Coastal Plain estuaries.

  6. River rating complexity

    Science.gov (United States)

    Holmes, Robert R.

    2016-01-01

    Accuracy of streamflow data depends on the veracity of the rating model used to derive a continuous time series of discharge from the surrogate variables that can readily be collected autonomously at a streamgage. Ratings are typically represented as a simple monotonic increasing function (simple rating), meaning the discharge is a function of stage alone, however this is never truly the case unless the flow is completely uniform at all stages and in transitions from one stage to the next. For example, at some streamflow-monitoring sites the discharge on the rising limb of the hydrograph is discernably larger than the discharge at the same stage on the falling limb of the hydrograph. This is the so-called “loop rating curve” (loop rating). In many cases, these loops are quite small and variation between rising- and falling-limb discharge measurements made at the same stage are well within the accuracy of the measurements. However, certain hydraulic conditions can produce a loop that is large enough to preclude use of a monotonic rating. A detailed data campaign for the Mississippi River at St. Louis, Missouri during a multi-peaked flood over a 56-day period in 2015 demonstrates the rating complexity at this location. The shifting-control method used to deal with complexity at this site matched all measurements within 8%.

  7. Geomorphology and landscape organization of a northern peatland complex

    Science.gov (United States)

    Richardson, M. C.

    2012-12-01

    The geomorphic evolution of northern peatlands is governed by complex ecohydrological feedback mechanisms and associated hydro-climatic drivers. For example, prevailing models of bog development (i.e. Ingram's groundwater mounding hypothesis and variants) attempt to explicitly link bog dome characteristics to the regional climate based on analytical and numerical models of lateral groundwater flow and the first-order control of water table position on rates of peat accumulation. In this talk I will present new results from quantitative geomorphic analyses of a northern peatland complex at the De Beers Victor diamond mine site in the Hudson Bay Lowlands of northern Ontario. This work capitalizes on spatially-extensive, high-resolution topographic (LiDAR) data to rigorously test analytical and numerical models of bog dome development in this landscape. The analysis and discussion are then expanded beyond individual bog formations to more broadly consider ecohydrological drivers of landscape organization, with implications for understanding and modeling catchment-scale runoff response. Results show that in this landscape, drainage patterns exhibit relatively well-organized characteristics consistent with observed runoff responses in six gauged research catchments. Interpreted together, the results of these geomorphic and hydrologic analyses help refine our understanding of water balance partitioning among different landcover types within northern peatland complexes. These findings can be used to help guide the development of appropriate numerical model structures for hydrologic prediction in ungauged peatland basins of northern Canada.

  8. Changes in planform geomorphology and vegetation of the Umatilla River during a 50-year period of diminishing peak flow

    Science.gov (United States)

    Hughes, M. L.; McDowell, P. F.

    2017-12-01

    The Umatilla River of northeastern Oregon is a gravel-bedded, mixed pattern, salmonid-bearing channel-floodplain system typical of the Interior Columbia River Basin. Efforts to restore native salmonids in this region since the 1980's coupled with increased scrutiny of flood- and erosion-control activities have prompted a need for better understanding of the biogemorphic implications of flood disturbances. The goals of this study are: (1) to re-examine results of earlier studies of flood impacts on the Umatilla River in light of more recent flow records, and (2) to investigate the degree to which large floods have influenced existing patterns of channel-floodplain geomorphology and vegetation. Mapping of flowing channels, bars, scoured surfaces, and vegetation within the active channel from of aerial photos bracketing flood and inter-flood periods since 1964 indicates complex and spatially variable channel changes. In general, channel scour was the most consistent response to flooding. The direction (gain/loss) and magnitude of changes in bars and vegetation within the active channel, as well as the amount of lateral channel movement and changes in sinuosity, were generally inconsistent across flood events. The removal of vegetation by scour during floods was in many areas compensated by the capture of vegetation from the floodplain by avulsion and activation of secondary channels. To date, the geomorphic impacts of the 1964-65 flood-of-record have not been replicated, despite an overall increase in the frequency of smaller floods. Expansion of riparian vegetation in recent decades has mainly occurred in areas disturbed by scour and bar deposition during the 1964-65 floods. Vegetative succession during this period has caused contraction of the active channel such that it now appears much as it did before the 1964-65 floods. These results underscore the importance of large floods as drivers of biogeormphic processes and patterns over timescales relevant to river

  9. Impacts of Declining Mississippi River Sediment Load on Subaqueous Delta Front Sedimentation and Geomorphology

    Science.gov (United States)

    Maloney, J. M.; Bentley, S. J.; Xu, K.; Georgiou, I. Y.; Miner, M. D.

    2016-02-01

    The Mississippi River delta system is undergoing unprecedented changes due to the effects of climate change and anthropogenic alterations to the river and its delta. Since the 1950s, the suspended sediment load of the Mississippi River has decreased by approximately 50% due to the construction of >50,000 dams in the Mississippi basin. The impact of this decreased sediment load has been observed in subaerial environments, but the impact on sedimentation and geomorphology of the subaqueous delta front has yet to be examined. To identify historic trends in sedimentation patterns, we compiled bathymetric datasets, including historical charts, industry and academic surveys, and NOAA data, collected between 1764 and 2009. Sedimentation rates are variable across the delta front, but are highest near the mouth of Southwest Pass, which carries the largest percentage of Mississippi River flow and sediment into the Gulf of Mexico. The progradation rate of Southwest Pass (measured at the 10 m depth contour) has slowed from 67 m/yr between 1764 and 1940 to 26 m/yr between 1940 and 1979, with evidence of further deceleration from 1979-2009. Decreased rates of progradation are also observed at South Pass and Pass A Loutre, with the 10 m contour retreating at rates >20 m/yr at both passes. Advancement of the delta front also decelerated in deeper water (15-90 m) offshore from Southwest Pass. In this area, from 1940-1979, depth contours advanced seaward 30 m/yr, but rates declined from 1979-2005. Furthermore, over the same area, the sediment accumulation rate decreased by 81% for the same period. The Mississippi River delta front appears to be entering a phase of decline, which will likely be accelerated by future upstream management practices. This decline has implications for offshore ecosystems, biogeochemical cycling, pollutant dispersal, mudflow hazard, and the continued use of the delta as an economic and population center.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-04-01

    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.

  11. Contemporary Conceptual Approaches in Fluvial Geomorphology

    Directory of Open Access Journals (Sweden)

    Mônica dos Santos Marçal

    2016-06-01

    Full Text Available Contemporary fluvial geomorphology faces challenging questions, especially as it goes by understanding the Late Holocene/Anthropocene period, which has repercussions today and are intrinsically important to understand the human river disturbance. Given the scale that physical rates operate in complex river systems, two conceptual paths were developed to analyze the spatial and temporal organization. The network view emphasizes controls on catchment-scale and a reach approach focuses on discontinuity and local controls. Fluvial geomorphology has seek to understand the organization of complex river systems from the integrated view of the continuity and discontinuity paradigm. This integrated approach has stimulated within the geomorphology, the emergence of new theoretical-methodological instruments. It is recognized that rivers management is an ongoing process, part of the socio-cultural development, which refers to both a social movement and scientific exercise.

  12. Geomorphological assessment of sites and impoundments for the long term containment of uranium mill tailings in the Alligator Rivers Region

    International Nuclear Information System (INIS)

    East, T.J.

    1986-01-01

    This paper presents a program of current and future research into those geomorphological processes likely to affect the long term containment of uranium mill tailings in the Alligator Rivers Region of the Northern Territory. Research is directed at three main areas: identification of geomorphic hazards at proposed impoundment sites; determination of erosion rates on impoundment slopes; and prediction of patterns of fluvial dispersal of released tailings. Each necessitates consideration of present and future geomorphic processes

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

    Directory of Open Access Journals (Sweden)

    João Bessa Santos

    2012-06-01

    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.

  14. Fluvial geomorphology and suspended-sediment transport during construction of the Roanoke River Flood Reduction Project in Roanoke, Virginia, 2005–2012

    Science.gov (United States)

    Jastram, John D.; Krstolic, Jennifer L.; Moyer, Douglas; Hyer, Kenneth

    2015-09-30

    Beginning in 2005, after decades of planning, the U.S. Army Corps of Engineers (USACE) undertook a major construction effort to reduce the effects of flooding on the city of Roanoke, Virginia—the Roanoke River Flood Reduction Project (RRFRP). Prompted by concerns about the potential for RRFRP construction-induced geomorphological instability and sediment liberation and the detrimental effects these responses could have on the endangered Roanoke logperch (Percina rex), the U.S. Geological Survey (USGS) partnered with the USACE to provide a real-time warning network and a long-term monitoring program to evaluate geomorphological change and sediment transport in the affected river reach. Geomorphological change and suspended-sediment transport are highly interdependent and cumulatively provide a detailed understanding of the sedimentary response, or lack thereof, of the Roanoke River to construction of the RRFRP.

  15. Geomorphological and morphometric analysis of the river basin of Salsa, south coast of the state of Paraiba / Brazil

    International Nuclear Information System (INIS)

    Barbosa, M.E.; Nascimento, J.; Furrier, M.

    2010-01-01

    This paper aims to extend the knowledge on the geomorphology of the river basin of Salsa , located in the municipality of Conde, State of Paraíba / Brazil . The research was to develop guiding object thematic maps related to morphometric aspects of the basin such as fluvial hierarchy , hypsometric and slope . After obtaining the morphometric data can assess the likely tectonic influences on the morphology of this basin. Literature searches , acquisition and analysis of cartographic data (satellite imagery , topographic and thematic maps), where with the help of software SPRING 5:03 , were made the thematic maps of the basin : For this research, the following milestones have been met. In addition, there have been two topographic profiles of the area through which it was possible to further analyze the geomorphological aspects and clinográficos watershed. Already in possession of the first results of this research it was observed with the analysis of charts and topographic profiles the high level of dissection Barriers Training and dissection of this discrepancy between the left and right margins . Barriers in Education, was observed indicative of tectonics from setbacks headwater quite different slots and obsequente towards the River Salsa (SN), which is discordant from the direction of the main waterways and Training Barriers own inclination is that WE . These findings are important because the geomorphological analysis of litoestatigráfica unit is of paramount importance for the understanding of the mechanisms governing the morphology of the northeast coast, mainly in relation to the mechanisms that govern the morphology of watersheds coast of Paraiba

  16. Rivers running deep : complex flow and morphology in the Mahakam River, Indonesia

    NARCIS (Netherlands)

    Vermeulen, B.

    2014-01-01

    Rivers in tropical regions often challenge our geomorphological understanding of fluvial systems. Hairpin bends, natural scours, bifurcate meander bends, tie channels and embayments in the river bank are a few examples of features ubiquitous in tropical rivers. Existing observation techniques

  17. Assessment of fluvial geomorphological change in the confluence of Chindwin and Ayeyarwady Rivers in Myanmar using remote sensing

    Science.gov (United States)

    Piman, T.; Vasconcelos, V. V.; Apirumanekul, C.; Krittasudthacheewa, C.

    2017-12-01

    assessment of remote sensing images also showed how Chindwin channel widened progressively due to bank erosion in the direction of Su Lay Kon and Ah Myning villages, in Monywa district. The rapid changes in river geomorphology calls for public's attention on alternative ways to live with these dynamic but important rivers.

  18. Geomorphological approach to surficial material evaluation in the Serang River Basin Kulonprogo, Yogyakarta, Indonesia

    Directory of Open Access Journals (Sweden)

    Sutikno .

    2013-07-01

    Among landform units in the studied area which contains a large amount of the materials are: natural levees, river terraces, river bed and hill foot slopes. Generally, the river bed materials decrease in grain size downstreams and increase in sphericity and roundness coefficient. In some cross sections a reversal was found to the general tendency. This situation might be due to human activities for getting material for construction. Due to human activities some environmental impacts occur.

  19. Hydromorphological control of nutrient cycling in complex river floodplain systems

    Science.gov (United States)

    Hein, T.; Bondar-Kunze, E.; Felkl, M.; Habersack, H.; Mair, M.; Pinay, G.; Tritthart, M.; Welti, N.

    2009-04-01

    Riparian zones and floodplains are key components within river ecosystems controlling nutrient cycling by promoting transformation processes and thus, act as biogeochemical hot spots. The intensity of these processes depends on the exchange conditions (the connectivity) with the main channel and the morphological setting of the water bodies. At the landscape scale, three interrelated principles of hydromorphological dynamics can be formulated regarding the cycling and transfer of carbon and nutrients in large rivers ecosystems: a) The mode of carbon and nutrient delivery affects ecosystem functioning; b) Increasing residence time and contact area impact nutrient transformation; c) Floods and droughts are natural events that strongly influence pathways of carbon and nutrient cycling. These three principles of hydromorphological dynamics control the nutrient uptake and retention and are linked over different temporal and spatial scales. All three factors can be strongly affected by natural disturbances or anthropogenic impacts, through a change in either the water regime or the geomorphologic setting of the river valley. Any change in natural water regimes will affect the biogeochemistry of riparian zones and floodplains as well as their ability to cycle and mitigate nutrient fluxes originating from upstream and/or upslope. Especially these areas have been altered by river regulation and land use changes over the last 200 years leading to the deterioration of the functioning of these compartments within the riverine landscape. The resulting deficits have prompted rehabilitation and restoration measures aiming to increase the spatial heterogeneity, the complexity, of these ecosystems. Yet, a more integrated approach is needed considering the present status of nutrient dynamics and the effects of restoration measures at different scales. The present paper analyses the effects of river side-arm restoration on ecosystem functions within the side-arm and highlights

  20. Factors influencing bank geomorphology and erosion of the Haw River, a high order river in North Carolina, since European settlement.

    Science.gov (United States)

    Macfall, Janet; Robinette, Paul; Welch, David

    2014-01-01

    The Haw River, a high order river in the southeastern United States, is characterized by severe bank erosion and geomorphic change from historical conditions of clear waters and connected floodplains. In 2014 it was named one of the 10 most threatened rivers in the United States by American Rivers. Like many developed areas, the region has a history of disturbance including extensive upland soil loss from agriculture, dams, and upstream urbanization. The primary objective of this study was to identify the mechanisms controlling channel form and erosion of the Haw River. Field measurements including bank height, bankfull height, bank angle, root depth and density, riparian land cover and slope, surface protection, river width, and bank retreat were collected at 87 sites along 43.5 km of river. A Bank Erosion Hazard Index (BEHI) was calculated for each study site. Mean bank height was 11.8 m, mean width was 84.3 m, and bank retreat for 2005/2007-2011/2013 was 2.3 m. The greatest bank heights, BEHI values, and bank retreat were adjacent to riparian areas with low slope (<2). This is in contrast to previous studies which identify high slope as a risk factor for erosion. Most of the soils in low slope riparian areas were alluvial, suggesting sediment deposition from upland row crop agriculture and/or flooding. Bank retreat was not correlated to bank heights or BEHI values. Historical dams (1.2-3 m height) were not a significant factor. Erosion of the Haw River in the study section of the river (25% of the river length) contributed 205,320 m3 of sediment and 3759 kg of P annually. Concentration of suspended solids in the river increased with discharge. In conclusion, the Haw River is an unstable system, with river bank erosion and geomodification potential influenced by riparian slope and varied flows.

  1. 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

    2017-03-01

    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.

  2. The contemporary geomorphology of the Letaba River in the Kruger National Park

    Directory of Open Access Journals (Sweden)

    B.P. Moon

    2001-07-01

    Full Text Available The Letaba River drains part of Northern Province in north-east South Africa. Its catchment has been modified significantly by human activity which has affected the flow regime; it experiences only ephemeral flows through the Kruger National Park to its confluence with the Olifants River. Although the Letaba is similar to the other rivers in the Kruger National Park in that it displays some bedrock influenced channel features, increased sediment delivery from the degraded catchment upstream has resulted in extensive alluviation within the channel. Sections of channel flowing over bedrock with no sediment covering are rare, and the river comprises a series of channel types: mixed anastomosing, alluvial braided, mixed pool-rapid and alluvial single thread. Each is characterised by a different combination of morphological units which relate to the degree of alluviation in the channel. These channel types are described in detail and inferences are made concerning their formation and maintenance from field observation and measurement.

  3. The contemporary geomorphology of the Sabie River in the Kruger National Park

    Directory of Open Access Journals (Sweden)

    G.L. Heritage

    2000-07-01

    Full Text Available The Sabie River in the Kruger National Park has been described as the most pristine in South Africa. It has remained largely free of direct alteration along its 110 km length within the reserve and as such displays a high geomorphic diversity. This physical vari- ability supports a great diversity of flora and fauna including a number of species endemic to the river. The diversity in fluvial form is the result of a high degree of bedrock influence coupled with a rapidly changing energy regime. Steeper bedrockinfluenced areas alternate with more gently sloping alluvial segments to create a series of channel types ranging from bedrock anastomosing through to alluvial single thread and braided sections. Each channel type is part of a continuum that relates to the degree of alluviation of the river on the bedrock template. Descriptions of the characteristic channel types associated with the Sabie River, together with associated morphologic units are given together with the areal extent of the changing morphology in the Kruger National Park. Each morphologic unit is characterised by size, shape, sedimentology and flow influence. Recent research into the degree and direction of morphologic change in the Sabie River is also summarised in the light of possible catchment management.

  4. Overview of geology, hydrology, geomorphology, and sediment budget of the Deschutes River Basin, Oregon.

    Science.gov (United States)

    Jim E. O' Connor; Gordon E. Grant; Tana L. Haluska

    2003-01-01

    Within the Deschutes River basin of central Oregon, the geology, hydrology, and physiography influence geomorphic and ecologic processes at a variety of temporal and spatial scales. Hydrologic and physiographic characteristics of the basin are related to underlying geologic materials. In the southwestern part of the basin, Quaternary volcanism and tectonism has created...

  5. The Palimpsest of River-Floodplain Management and the Role of Geomorphology

    NARCIS (Netherlands)

    Hudson, Paul F; Middelkoop, Hans

    2015-01-01

    Embanked floodplains are the status-quo where humans are a major component of the environment, especially across Europe and North America. Effective management of embanked rivers requires a comprehensive knowledge of past and present-day geomorphic processes, including sediment transport and channel

  6. Hydrology, geomorphology, and vegetation of Coastal Plain rivers in the southeastern United States

    Science.gov (United States)

    Cliff R. Hupp

    2000-01-01

    Rivers of the Coastal Plain of the southeastern United States are characteristically low-gradient meandering systems that develop broad floodplains subjected to frequent and prolonged flooding. These floodplains support a relatively unique forested wetland (Bottomland Hardwoods), which have received considerable ecological study, but distinctly less hydrogeomorphic...

  7. A geomorphological assessments of the distribution of sediment sinks along the lower Amazon River

    Science.gov (United States)

    Park, E.; Latrubesse, E. M.

    2017-12-01

    Floodplain sediment storage budget is examined along the 1,000 km reach of the lower Amazon River based on extensive sets of remote sensing data and field measurements. Incorporating the washload discharges at gauge stations at the main channel and major tributaries, we analyzed the roles of vast floodplain on the Amazon River seasonal variability in sediment discharges. Annual washload accumulation rate on floodplain along the reach in between Manacapuru and Obidos of is estimated to be 79 Mt over inter-annual average. Period that the net loss over to the floodplain of washload coincide with discharge rising phase of the Amazon River at Obidos, when the river water level rises to make hydrologic connections to floodplain. Only during the early falling phase (July-August), 3.6 Mt of washload net gain occurred in a year, which was less than 5% of the annual net loss to the floodplain. To assess the spatial distribution of sediment sinks along the lower Amazon, we incorporated various hydro-geomorphic factors regarding floodplain geomorphic styles and morphometric parameters, such floodplain width, levee heights, water-saturated area, suspended sediment distribution over floodplain and distribution of impeded floodplain. Impeded floodplain that contains numerous large rounded lakes is the definition of active sediment sinks along the lower Amazon, which seasonally stores most of the water and traps sediment from the river. The results of these hydro-geomorphic factors collectively indicate that the extent and magnitudes of sediment sinks becomes larger downstream (from Manacapuru to Monte Alegre), which is proportionally related to the development of the water-saturated floodplain. This indicates the nonlinear geomorphic evolution of the Amazon floodplain through its longitudinal profile since the late Holocene that downstream reaches are still to be infilled with sediments (incomplete floodplain) thus acting as sediment sinks.

  8. Geomorphological assessment of sites and impoundments for the long term containment of uranium mill tailings in the Alligator Rivers Region

    International Nuclear Information System (INIS)

    East, T.J.

    1985-01-01

    Current and future research into the geomorphological processes likely to affect the long term containment of uranium mill tailings in the Alligator Rivers Region is directed at three main areas: identification of geomorphic hazards at proposed impoundment sites; determination of erosion rates on impoundment slopes; and prediction of patterns of fluvial dispersal of released tailings. Each necessitates consideration of present and future geomorphic processes. Process rates during the next few thousand years might be predictable by extrapolation of contemporary and past (i.e. Holocene) climates, sea-levels and depositional environments, evidence for which is preserved in the sedimentary record. In current projects, the Late Quarternary stratigraphy of Magela Creek are examined to provide data for modelling of present and future sedimentological processes. Site stability evaluation entails recognition of present and future geomorphic hazards at impoundment sites, and includes fluvial and hillslope erosion, extreme flood events and mass movements. The life of a tailings impoundment is further determined by the intensity of erosional processes acting upon its slopes and their cover materials. A knowledge of present and future erosion rates will allow the optimisation of slope characteristics and materials in the impoundment design

  9. Learning from Nature - Mapping of Complex Hydrological and Geomorphological Process Systems for More Realistic Modelling of Hazard-related Maps

    Science.gov (United States)

    Chifflard, Peter; Tilch, Nils

    2010-05-01

    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

  10. Local models for rainstorm-induced hazard analysis on Mediterranean river-torrential geomorphological systems

    Directory of Open Access Journals (Sweden)

    N. Diodato

    2004-01-01

    Full Text Available Damaging hydrogeomorphological events are defined as one or more simultaneous phenomena (e.g. accelerated erosions, landslides, flash floods and river floods, occurring in a spatially and temporal random way and triggered by rainfall with different intensity and extent. The storm rainfall values are highly dependent on weather condition and relief. However, the impact of rainstorms in Mediterranean mountain environments depend mainly on climatic fluctuations in the short and long term, especially in rainfall quantity. An algorithm for the characterisation of this impact, called Rainfall Hazard Index (RHI, is developed with a less expensive methodology. In RHI modelling, we assume that the river-torrential system has adapted to the natural hydrological regime, and a sudden fluctuation in this regime, especially those exceeding thresholds for an acceptable range of flexibility, may have disastrous consequences for the mountain environment. RHI integrate two rainfall variables based upon storm depth current and historical data, both of a fixed duration, and a one-dimensionless parameter representative of the degree ecosystem flexibility. The approach was applied to a test site in the Benevento river-torrential landscape, Campania (Southern Italy. So, a database including data from 27 events which have occurred during an 77-year period (1926-2002 was compared with Benevento-station RHI(24h, for a qualitative validation. Trends in RHIx for annual maximum storms of duration 1, 3 and 24h were also examined. Little change is observed at the 3- and 24-h duration of a storm, but a significant increase results in hazard of a short and intense storm (RHIx(1h, in agreement with a reduction in return period for extreme rainfall events.

  11. Tectonic Geomorphology.

    Science.gov (United States)

    Bull, William B.

    1984-01-01

    Summarizes representative quantitative tectonic-geomorphology studies made during the last century, focusing on fault-bounded mountain-front escarpments, marine terraces, and alluvial geomorphic surfaces (considering stream terraces, piedmont fault scarps, and soils chronosequences). Also suggests where tectonic-geomorphology courses may best fit…

  12. Geomorphological Fieldwork

    Science.gov (United States)

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

    2014-01-01

    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.

  13. The influence of floodplain geomorphology and hydrologic connectivity on alligator gar (Atractosteus spatula) habitat along the embanked floodplain of the Lower Mississippi River

    Science.gov (United States)

    van der Most, Merel; Hudson, Paul F.

    2018-02-01

    The floodplain geomorphology of large lowland rivers is intricately related to aquatic ecosystems dependent upon flood pulse dynamics. The alligator gar (Atractosteus spatula) is native to the Lower Mississippi River and dependent upon floodplain backwater areas for spawning. In this study we utilize a geospatial approach to develop a habitat suitability index for alligator gar that explicitly considers hydrologic connectivity and the floodplain geomorphology along a frequently inundated segment of the Lower Mississippi River. The data sets include Landsat imagery, a high-resolution LiDAR digital elevation model (DEM), National Hydrography Dataset (NHD), and hydrologic and geomorphic data. A habitat suitability index is created based on the extent and frequency of inundation, water depth, temperature, and vegetation. A comparison between the remote sensing approach and the NHD revealed substantial differences in the area and location of water bodies available for alligator gar spawning. The final habitat suitability index indicates that a modest proportion (19%) of the overall embanked floodplain is available for alligator gar spawning. Opportunities exist for management efforts to utilize engineered and natural geomorphic features to facilitate hydrologic connectivity at flow levels below flood stage that would expand the habitat of alligator gar across the floodplain. The study results have direct implications regarding environmental restoration of the Lower Mississippi, an iconic example of an embanked meandering river floodplain.

  14. Geomorphology: A Canadian Perspective

    Science.gov (United States)

    Pizzuto, Jim

    Geomorphology is a hot discipline. Recent interest in river restoration, climate change, geomorphic hazards such as landslides and tsunamis, controlled floods, and other issues has increased the visibility of geomorphology as a profession. New methods involving the Global Positioning System, remote sensing, numerical simulation, laboratory experimentation, and novel dating techniques have created new research opportunities. The number of jobs in academia, industry, and the public sector is rising. What is the best way to convey this excitement to students, while at the same time properly training them? The traditional approach is an introductory course at the undergraduate level, built around a general textbook. When I teach geomorphology, I do not use a textbook but rather rely on original readings and field-based exercises to introduce students to geomorphic concepts and methods.

  15. Surficial geological tools in fluvial geomorphology: Chapter 2

    Science.gov (United States)

    Jacobson, Robert B.; O'Connor, James E.; Oguchi, Takashi

    2016-01-01

    Increasingly, environmental scientists are being asked to develop an understanding of how rivers and streams have been altered by environmental stresses, whether rivers are subject to physical or chemical hazards, how they can be restored, and how they will respond to future environmental change. These questions present substantive challenges to the discipline of fluvial geomorphology, especially since decades of geomorphologic research have demonstrated the general complexity of fluvial systems. It follows from the concept of complex response that synoptic and short-term historical views of rivers will often give misleading understanding of future behavior. Nevertheless, broadly trained geomorphologists can address questions involving complex natural systems by drawing from a tool box that commonly includes the principles and methods of geology, hydrology, hydraulics, engineering, and ecology.

  16. Geomorphology Influencing the Diversification of Fish in Small-Order Rivers of Neighboring Basins.

    Science.gov (United States)

    Morais-Silva, João P; Oliveira, Alessandra V de; Fabrin, Thomaz M C; Diamante, Nathália Alves; Prioli, Sônia M A P; Frota, Augusto; Graça, Weferson J da; Prioli, Alberto J

    2018-03-13

    The current analysis investigates whether the uplift of the Serra da Esperança and the Ponta Grossa Arch in the Serra Geral resulted in ichthyofaunistic changes in adjacent basins. For this, we describe the phylogeographic structure among populations of Trichomycterus collected in hydrographic basins in southern Brazil by using partial nucleotide sequences of the mitochondrial gene Cytochrome C Oxidase subunit I. Analyses revealed that the nomenclature Trichomycterus davisi fails to contain the whole genetic diversity range found in the collected specimens and indicates at least six genetic lineages in Trichomycterus. Diagnostic morphological characteristics not associated to T. davisi could be identified in some specimens from the Iguaçu Piquiri haplogroup, indicating the occurrence of species Trichomycterus stawiarski. The lack of morphological differences among the other clades clearly suggests a cryptic species case. Molecular analyses revealed at least five new species besides T. davisi in the hydrographic basins and support the interpretation that genetic structure in T. davisi species complex is explained by tectonic events intrinsic to the areas of influence of Serra da Esperança and the Ponta Grossa Arch which occurred around 1.7 My.

  17. MULTI-DECADAL FLUVIO-GEOMORPHOLOGICAL AND BANKLINE CHANGES OF THE GANGA RIVER AROUND BALLIA AND RUDRAPUR USING REMOTE SENSING AND GIS TECHNIQUES

    Directory of Open Access Journals (Sweden)

    A. J. Desai

    2012-09-01

    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.

  18. Planetary Geomorphology.

    Science.gov (United States)

    Baker, Victor R.

    1984-01-01

    Discusses various topics related to planetary geomorphology, including: research techniques; such geomorphic processes as impact, volcanic, degradational, eolian, and hillslope/mass movement processes; and channels and valleys. Indicates that the subject should be taught as a series of scientific questions rather than scientific results of…

  19. Periglacial Geomorphology.

    Science.gov (United States)

    Potter, Noel, Jr.

    1984-01-01

    Describes preglacial processes, focusing on weathering, rate and timing of movement of material, snow and snow avalanches, rock glaciers, gelifluction, pingos, patterned ground, and the thaw of permafrost. This information is provided for individuals teaching introductory geology/geomorphology and whose specialty is not cold-climate phenomena. (JN)

  20. Geomorphology of the Elwha River and its Delta: Chapter 3 in Coastal habitats of the Elwha River, Washington--biological and physical patterns and processes prior to dam removal

    Science.gov (United States)

    Warrick, Jonathan A.; Draut, Amy E.; McHenry, Michael L.; Miller, Ian M.; Magirl, Christopher S.; Beirne, Matthew M.; Stevens, Andrew Stevens; Logan, Joshua B.; Duda, Jeffrey J.; Warrick, Jonathan A.; Magirl, Christopher S.

    2011-01-01

    The removal of two dams on the Elwha River will introduce massive volumes of sediment to the river, and this increase in sediment supply in the river will likely modify the shapes and forms of the river and coastal landscape downstream of the dams. This chapter provides the geologic and geomorphologic background of the Olympic Peninsula and the Elwha River with emphasis on the present river and shoreline. The Elwha River watershed was formed through the uplift of the Olympic Mountains, erosion and movement of sediment throughout the watershed from glaciers, and downslope movement of sediment from gravitational and hydrologic forces. Recent alterations to the river morphology and sediment movement through the river include the two large dams slated to be removed in 2011, but also include repeated bulldozing of channel boundaries, construction and maintenance of flood plain levees, a weir and diversion channel for water supply purposes, and engineered log jams to help enhance river habitat for salmon. The shoreline of the Elwha River delta has changed in location by several kilometers during the past 14,000 years, in response to variations in the local sea-level of approximately 150 meters. Erosion of the shoreline has accelerated during the past 80 years, resulting in landward movement of the beach by more than 200 meters near the river mouth, net reduction in the area of coastal wetlands, and the development of an armored low-tide terrace of the beach consisting primarily of cobble. Changes to the river and coastal morphology during and following dam removal may be substantial, and consistent, long-term monitoring of these systems will be needed to characterize the effects of the dam removal project.

  1. The environmental and geomorphological impacts of historical gold mining in the Ohinemuri and Waihou river catchments, Coromandel, New Zealand

    Czech Academy of Sciences Publication Activity Database

    Alastair, J. H. C.; Nováková, Tereza; Hudson-Edwards, K. A.; Fuller, I. C.; Macklin, M. G.; Fox, E. G.; Zapico, I.

    2017-01-01

    Roč. 295, OCT 15 2017 (2017), s. 159-175 ISSN 0169-555X Institutional support: RVO:67985831 Keywords : mining-contaminated river * floodplain sedimentation * mine tailing discharge * historical gold mining * Ohinemuri River * Waihou River Subject RIV: DO - Wilderness Conservation OBOR OECD: Environmental sciences (social aspects to be 5.7) Impact factor: 2.958, year: 2016

  2. Role of neotectonics and climate in development of the Holocene geomorphology and soils of the Gangetic Plains between the Ramganga and Rapti rivers

    Science.gov (United States)

    Srivastava, Pankaj; Parkash, B.; Sehgal, J. L.; Kumar, Sudhir

    1994-12-01

    Fifteen soil-geomorphic units have been delineated from the Gangetic Plains between the Ramganga and Rapti rivers. They were identified by remote sensing and field checks. On the basis of degree of profile development, their soils are grouped into five members (QGH1 to QGH5, QGH5 being the oldest) of a soil chrono-association. Tentative ages assigned to QGH1 to QGH5 are 500, > 2500, 8000 and 13,5000 yr B.P., respectively. From the early Holocene to about 6500 yr. B.P. a cold, arid to semi-arid climate prevailed and pedogenic calcrete developed over large areas in the Gangetic Plains. Later, a warm and humid climate and improved drainage resulted in complete removal of calcrete from soil profiles in some areas or its dissolution and re-precipitation in lower horizons in other areas. Neotectonics seems to have played a significant role in the evolution of the geomorphology and soils of the area. It determined areas of active sedimentation, pedogenesis and erosion (in upland regions). It led to tilting and sagging of large blocks resulting in shifting and increase in sinuosity of the rivers. Tectonic slopes/faults determined the courses of large rivers.

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

    DEFF Research Database (Denmark)

    Brandt, Anders

    2000-01-01

    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...

  4. 3D terrestrial lidar data classification of complex natural scenes using a multi-scale dimensionality criterion: Applications in geomorphology

    Science.gov (United States)

    Brodu, N.; Lague, D.

    2012-03-01

    3D point clouds of natural environments relevant to problems in geomorphology (rivers, coastal environments, cliffs, …) often require classification of the data into elementary relevant classes. A typical example is the separation of riparian vegetation from ground in fluvial environments, the distinction between fresh surfaces and rockfall in cliff environments, or more generally the classification of surfaces according to their morphology (e.g. the presence of bedforms or by grain size). Natural surfaces are heterogeneous and their distinctive properties are seldom defined at a unique scale, prompting the use of multi-scale criteria to achieve a high degree of classification success. We have thus defined a multi-scale measure of the point cloud dimensionality around each point. The dimensionality characterizes the local 3D organization of the point cloud within spheres centered on the measured points and varies from being 1D (points set along a line), 2D (points forming a plane) to the full 3D volume. By varying the diameter of the sphere, we can thus monitor how the local cloud geometry behaves across scales. We present the technique and illustrate its efficiency in separating riparian vegetation from ground and classifying a mountain stream as vegetation, rock, gravel or water surface. In these two cases, separating the vegetation from ground or other classes achieve accuracy larger than 98%. Comparison with a single scale approach shows the superiority of the multi-scale analysis in enhancing class separability and spatial resolution of the classification. Scenes between 10 and one hundred million points can be classified on a common laptop in a reasonable time. The technique is robust to missing data, shadow zones and changes in point density within the scene. The classification is fast and accurate and can account for some degree of intra-class morphological variability such as different vegetation types. A probabilistic confidence in the classification

  5. Influences of micro-geomorphology on the stoichiometry of C, N and P in Chenier Island soils and plants in the Yellow River Delta, China.

    Science.gov (United States)

    Qu, Fanzhu; Meng, Ling; Yu, Junbao; Liu, Jingtao; Sun, Jingkuan; Yang, Hongjun; Dong, Linshui

    2017-01-01

    Studies have indicated that consistent or well-constrained (relatively low variability) carbon:nitrogen:phosphorus (C:N:P) ratios exist in large-scale ecosystems, including both marine and terrestrial ecosystems. Little is known about the C, N and P stoichiometric ratios that exist in the soils and plants of Chenier Island in the Yellow River Delta (YRD). We examined the distribution patterns and relationships of C, N and P stoichiometry in the soils and plants of Chenier Island, as well as the potential influences of the island's micro-geomorphology. Based on a study of four soil profile categories and Phragmites australis and Suaeda heteroptera plant tissues, our results showed that micro-geomorphology could leave a distinct imprint on the soil and plant elemental stoichiometry of Chenier Island; significant variation in the atomic C:N:P ratios (RCNP) existed in soils and plants, indicating that the RCNP values in both the soil and plants are not well constrained at the Chenier Island scale. RCN and RCP in Chenier Island soils were high, whereas the RNP values were comparatively low, indicating that the ecosystems of Chenier Island are nutrient-limited by N and P. However, the RNP values in P. australis and S. heteroptera plant tissues were high, suggesting that the plants of Chenier Island are nutrient-limited by P. Finally, we suggest that soil and plant N:P ratios may be good indicators of the soil and plant nutrient status during soil development and plant growth, which could be a useful reference for restoring the degraded soils of Chenier Island.

  6. Global Geomorphology

    Science.gov (United States)

    Douglas, I.

    1985-01-01

    Any global view of landforms must include an evaluation of the link between plate tectonics and geomorphology. To explain the broad features of the continents and ocean floors, a basic distinction between the tectogene and cratogene part of the Earth's surface must be made. The tectogene areas are those that are dominated by crustal movements, earthquakes and volcanicity at the present time and are essentially those of the great mountain belts and mid ocean ridges. Cratogene areas comprise the plate interiors, especially the old lands of Gondwanaland and Laurasia. Fundamental as this division between plate margin areas and plate interiors is, it cannot be said to be a simple case of a distinction between tectonically active and stable areas. Indeed, in terms of megageomorphology, former plate margins and tectonic activity up to 600 million years ago have to be considered.

  7. Modeling Surface Water Dynamics in the Amazon Basin Using Mosart-Inundation-v1.0: Impacts of Geomorphological Parameters and River Flow Representation

    Science.gov (United States)

    Luo, Xiangyu; Li, Hong-Yi; Leung, Ruby; Tesfa, Teklu K.; Getirana, Augusto; Papa, Fabrice; Hess, Laura L.

    2017-01-01

    Surface water dynamics play an important role in water, energy and carbon cycles of the Amazon Basin. A macro-scale inundation scheme was integrated with a surface-water transport model and the extended model was applied in this vast basin. We addressed the challenges of improving basin-wide geomorphological parameters and river flow representation for 15 large-scale applications. Vegetation-caused biases embedded in the HydroSHEDS DEM data were alleviated by using a vegetation height map of about 1-km resolution and a land cover dataset of about 90-m resolution. The average elevation deduction from the DEM correction was about 13.2 m for the entire basin. Basin-wide empirical formulae for channel cross-sectional geometry were adjusted based on local information for the major portion of the basin, which could significantly reduce the cross-sectional area for the channels of some subregions. The Manning roughness coefficient of the channel 20 varied with the channel depth to reflect the general rule that the relative importance of riverbed resistance in river flow declined with the increase of river size. The entire basin was discretized into 5395 subbasins (with an average area of 1091.7 km2), which were used as computation units. The model was driven by runoff estimates of 14 years (1994 2007) generated by the ISBA land surface model. The simulated results were evaluated against in situ streamflow records, and remotely sensed Envisat altimetry data and GIEMS inundation data. The hydrographs were reproduced fairly well for the majority of 25 13 major stream gauges. For the 11 subbasins containing or close to 11 of the 13 gauges, the timing of river stage fluctuations was captured; for most of the 11 subbasins, the magnitude of river stage fluctuations was represented well. The inundation estimates were comparable to the GIEMS observations. Sensitivity analyses demonstrated that refining floodplain topography, channel morphology and Manning roughness coefficients

  8. Geomorphology and geologic characteristics of the Savannah River floodplain in the vicinity of the Savannah River Site, South Carolina and Georgia

    International Nuclear Information System (INIS)

    Leeth, D.C.; Nagle, D.D.

    1994-01-01

    The potential for migration of contaminated ground water from the US Department of Energy Savannah River Site (SRS) beneath the Savannah River into Georgia (trans-river flow) is a subject of recent environmental concern. The degree of incision of the ancestral Savannah River into the local hydrogeologic framework is a significant consideration in the assessment of trans-river flow. The objective of this investigation is to identify the geologic formations which subcrop beneath the alluvium and the extent to which the river has incised regional confining beds. To meet this objective 18 boreholes were drilled to depths of 25 to 100 feet along three transects across the present floodplain. These borings provided data on the hydrogeologic character of the strata that fill the alluvial valley. The profiles from the borehole transects were compared with electrical conductivity (EM-34) data to ascertain the applicability of this geophysical technique to future investigations

  9. Salmonids, stream temperatures, and solar loading--modeling the shade provided to the Klamath River by vegetation and geomorphology

    Science.gov (United States)

    Forney, William M.; Soulard, Christopher E.; Chickadel, C. Christopher

    2013-01-01

    The U.S. Geological Survey is studying approaches to characterize the thermal regulation of water and the dynamics of cold water refugia. High temperatures have physiological impacts on anadromous fish species. Factors affecting the presence, variability, and quality of thermal refugia are known, such as riverine and watershed processes, hyporheic flows, deep pools and bathymetric factors, thermal stratification of reservoirs, and other broader climatic considerations. This research develops a conceptual model and methodological techniques to quantify the change in solar insolation load to the Klamath River caused by riparian and floodplain vegetation, the morphology of the river, and the orientation and topographic characteristics of its watersheds. Using multiple scales of input data from digital elevation models and airborne light detection and ranging (LiDAR) derivatives, different analysis methods yielded three different model results. These models are correlated with thermal infrared imagery for ground-truth information at the focal confluence with the Scott River. Results from nonparametric correlation tests, geostatistical cross-covariograms, and cross-correlograms indicate that statistical relationships between the insolation models and the thermal infrared imagery exist and are significant. Furthermore, the use of geostatistics provides insights to the spatial structure of the relationships that would not be apparent otherwise. To incorporate a more complete representation of the temperature dynamics in the river system, other variables including the factors mentioned above, and their influence on solar loading, are discussed. With similar datasets, these methods could be applied to any river in the United States—especially those listed as temperature impaired under Section 303(d) of the Clean Water Act—or international riverine systems. Considering the importance of thermal refugia for aquatic species, these methods can help investigate opportunities

  10. The environmental and geomorphological impacts of historical gold mining in the Ohinemuri and Waihou river catchments, Coromandel, New Zealand

    Science.gov (United States)

    Clement, Alastair J. H.; Nováková, Tereza; Hudson-Edwards, Karen A.; Fuller, Ian C.; Macklin, Mark G.; Fox, Elizabeth G.; Zapico, Ignacio

    2017-10-01

    Between 1875 and 1955 approximately 250,000 Mg yr- 1 of mercury-, arsenic-, and cyanide-contaminated mine tailings were discharged directly into the Ohinemuri River and its tributaries, in the Coromandel Region, North Island, New Zealand. A devastating flood on 14 January 1907 deposited large amounts of mine waste across the floodplain of the Ohinemuri and Waihou rivers in the vicinity of the township of Paeroa. The 1907 mine-waste flood deposit was located as a dirty yellow silt in cores and floodplain profiles, with a thickness ranging from 0.15-0.50 m. Geochemical analysis of the mine waste shows elevated concentrations of Pb ( 200-570 mg kg- 1) and As ( 30-80 mg kg- 1), compared to early Holocene background concentrations (Pb metalloids that pose a long-term risk to the Ohinemuri and Waihou ecosystems.

  11. Development of fauna of water beetles (Coleoptera in waters bodies of a river valley – habitat factors, landscape and geomorphology

    Directory of Open Access Journals (Sweden)

    Pakulnicka Joanna

    2016-01-01

    Full Text Available The goal of the study was to identify the beetle fauna of a small lowland river valley against its spatial arrangement and the directions of beetle migrations between habitats, as well as to determine which environmental factors affect the characteristics of water beetle populations in a river valley's lentic water bodies. The field studies were carried out in various types of water bodies. 112 species of beetles with various ecological characteristics were identified. It was demonstrated that the diversity of water bodies in the valley is conducive to high local species richness. At the same time, the observed high degree of faunistic individualism may be regarded as a sign of poor symmetry in the directions of fauna propagation, particularly that of stagnobionts. The authors argue that high individualism is the consequence of poor hydrological contact between the water bodies due to topography and rare instances of high tide in the river, which, in turn, is the reason for active overflights remaining the main mean of migration between those water bodies. The factors restricting migration of fauna between the water bodies include certain landscape characteristics of the catchment which form topographical obstacles, mainly numerous and dense forest areas. The character of fauna in the respective types of water bodies is affected also by internal environmental factors, particularly the degree to which they are overgrown with macrophytes, type of bottom, type of mineral and organic matter as well as physical parameters of water, such as saturation, pH, temperature and biological oxygen demand.

  12. Geographic Information Systems and geomorphological mapping applied to landslide inventory and susceptibility mapping in El Estado river, Pico de Orizaba, Mexico

    Directory of Open Access Journals (Sweden)

    José Fernando Aceves Quesada

    2016-11-01

    -off switching of layers in the GIS system, a base map is created to assist in the digitizing of landslides and the modeling of susceptibility. A landslide inventory is created from aerial photographs, field investigations, and all the above GIS thematic layers. El Estado river watershed on the southwestern flank of Pico de Orizaba volcano has been selected as study area. The watershed is located in the southwestern slope of Citlaltepetl or Pico de Orizaba volcano. Geological (the stream channel of El Estado river erodes Tertiary and Quaternary lavas, disjointed volcanoclastic materials such as pyroclastic flows, fall deposits, lahars deposits, and alluvium and geomorphological factors (steep slopes, energy relief, and vertical erosion in combination with high seasonal rainfall (annual rainfall averages 1000-1100 mm/yr at > 4000 m a.s.l. and 927 mm/yr at <1500 m a.s.l., and the high degree of weathering, make the study area susceptible to landslides. To assess landslide susceptibility, a landslide inventory map and geomorphometric cartography (altimetry, slope and geomorphography were reviewed, and field work was conducted. In the study area, more than one hundred landslides were mapped. Shallow landslides (including debris slides and debris flows are the predominant type. Shallow landslides predominate on hills capped with ash and pyroclastic deposits. The second major landslide process includes rock falls (which occur where the stream erodes lava flows and lahars and deep-seated landslides (which occur in ash and pyroclastic deposits where lava flows act as a slip plane. In parallel, the spatial geodatabase of landslides was constructed from standardized GIS datasets. Pertinent attributes are recorded on a geo-dataset. These include 1 mass wasting process, 2 level of certainty of the observation, 3 photo identification date, 4 landslide size, 5 landslide activity, 6 landslide parts (head, evacuation zone, deposit, 7 slope shape, 8 field slope gradient, 9 map gradient measured

  13. Old River Control Complex Sedimentation Investigation

    Science.gov (United States)

    2015-06-01

    investigation was conducted via a combination of field data collection and laboratory analysis, geomorphic assessments, and numerical modeling . The...Diversion Mississippi river Sediment Shoaling Numerical modeling Field data collection Geomorphic assessment 16. SECURITY CLASSIFICATION OF...District, New Orleans. The investigation was conducted via a combination of field data collection and laboratory analysis, geomorphic assessments, and

  14. Inlet Geomorphology Evolution

    Science.gov (United States)

    2015-04-01

    APR 2015 2. REPORT TYPE 3. DATES COVERED 00-00-2015 to 00-00-2015 4. TITLE AND SUBTITLE Inlet Geomorphology Evolution 5a. CONTRACT NUMBER 5b...Std Z39-18 Coastal Inlets Research Program Inlet Geomorphology Evolution The Inlet Geomorphology Evolution work unit of the CIRP evaluates

  15. Mercury in the Calcasieu River/lake Complex, Louisiana

    International Nuclear Information System (INIS)

    Mueller, C.S.; Ramelow, G.J.; Beck, J.N.

    1989-01-01

    The Calcasieu River/Lake Complex is of great economic importance to southwestern Louisiana. Calcasieu Lake is an important fishing ground for shrimp and oysters. The Calcasieu River/Lake Complex has been the focus of an interdisciplinary study to assess the types and areas of pollution along this important waterway. Particular attention has been given to Hg because of the toxicity of this metal, and the local importance of the chloralkali industry--an industry that is known to discharge Hg into the environment. Water, sediment and biota were collected at stations in Calcasieu Lake, Calcasieu River, and along three bayou tributaries that were studied intensively. Intensive sampling included all stations along the particular bayou studied that month

  16. Curriculum Development in Geomorphology.

    Science.gov (United States)

    Gregory, Kenneth J.

    1988-01-01

    Examines the context of present curriculum development in geomorphology and the way in which it has developed in recent years. Discusses the content of the geomorphology curriculum in higher education and the consequences of curriculum development together with a consideration of future trends and their implications. (GEA)

  17. Lower Snake River Juvenile Salmon Migration Feasibility Report/Environmental Impact Statement. Appendix F: Hydrology/Hydraulics and Sedimentation. Appendix G: Hydroregulations. Appendix H: Fluvial Geomorphology

    National Research Council Canada - National Science Library

    2002-01-01

    ... (collectively called the Lower Snake River Project) and their effects on four lower Snake River salmon and steelhead stocks listed for protection under the Endangered Species Act (ESA). The U.S...

  18. Geomorphology and seismic risk

    Science.gov (United States)

    Panizza, Mario

    1991-07-01

    The author analyses the contributions provided by geomorphology in studies suited to the assessment of seismic risk: this is defined as function of the seismic hazard, of the seismic susceptibility, and of the vulnerability. The geomorphological studies applicable to seismic risk assessment can be divided into two sectors: (a) morpho-neotectonic investigations conducted to identify active tectonic structures; (b) geomorphological and morphometric analyses aimed at identifying the particular situations that amplify or reduce seismic susceptibility. The morpho-neotectonic studies lead to the identification, selection and classification of the lineaments that can be linked with active tectonic structures. The most important geomorphological situations that can condition seismic susceptibility are: slope angle, debris, morphology, degradational slopes, paleo-landslides and underground cavities.

  19. Geomorphology of Minnesota

    Data.gov (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...

  20. Geomorphology, tectonics, and exploration

    Science.gov (United States)

    Sabins, F. F., Jr.

    1985-01-01

    Explorationists interpret satellite images for tectonic features and patterns that may be clues to mineral and energy deposits. The tectonic features of interest range in scale from regional (sedimentary basins, fold belts) to local (faults, fractures) and are generally expressed as geomorphic features in remote sensing images. Explorationists typically employ classic concepts of geomorphology and landform analysis for their interpretations, which leads to the question - Are there new and evolving concepts in geomorphology that may be applicable to tectonic analyses of images?

  1. The River Mondego terraces at the Figueira da Foz coastal area (western central Portugal): Geomorphological and sedimentological characterization of a terrace staircase affected by differential uplift and glacio-eustasy

    DEFF Research Database (Denmark)

    Ramos, Anabela M.; Cunha, Pedro P.; Cunha, Lúcio. S.

    2012-01-01

    A geomorphological and sedimentological characterization of the River Mondego terraces in the Figueira da Foz coastal area, Portugal, is presented. The relief is dominated by a Pliocene a marine sandy unit ~ 10–15 m thick, reaching ~ 250 m a.s.l., that covers a shore platform surface. The River...... of terrace genesis in this coastal area should be dominated by glacio-eustasy whereby episodic valley incision would have been determined by periods of very low sea-level, probably at ~ 460–410 ka (T3/T4; MIS12), ~ 200–125 ka (T4/T5; MIS6) and 100–14 ka (T5/Recent alluvial infill; late MIS5, MIS4, MIS3......-gravels and silts, but also some colluvium at the top of each terrace. The younger terraces (T3, T4 and T5) show better developed sedimentary structures and less sedimentary matrix; the sedimentary features are indicative of both fluvial and coastal environments (estuary and beach, as nowadays). Under conditions...

  2. Geomorphology and spatial planning

    Directory of Open Access Journals (Sweden)

    Matija Zorn

    2006-01-01

    Full Text Available Applicability of geomorphological knowledge for prevention against some natural disasters, also known as geomorphological disasters, is presented. Some home and foreign experience of applicability of this knowledge are introduced. It is known that the ratio between means put into sanitation of, for example, landslides and savings with prevention measures, are from 1:10 to 1:2.000. The use of geomorpholgical knowledge and corresponding cartographic works in Slovene spatial planning legislation is defined, but it is not carried out consistently. We recommend municipalities and spatial planners that they should also take in account geomorphic processes and characteristic of the relief.

  3. A New Global Geomorphology?

    Science.gov (United States)

    Baker, V. R.

    1985-01-01

    Geomorphology is entering a new era of discovery and scientific excitement centered on expanding scales of concern in both time and space. The catalysts for this development include technological advances in global remote sensing systems, mathematical modeling, and the dating of geomorphic surfaces and processes. Even more important are new scientific questions centered on comparative planetary geomorphology, the interaction of tectonism with landscapes, the dynamics of late Cenozoic climatic changes, the influence of cataclysmic processes, the recognition of extremely ancient landforms, and the history of the world's hydrologic systems. These questions all involve feedback relationships with allied sciences that have recently yielded profound developments.

  4. Seasonal and inter-annual dynamics of suspended sediment at the mouth of the Amazon river: The role of continental and oceanic forcing, and implications for coastal geomorphology and mud bank formation

    Science.gov (United States)

    Gensac, Erwan; Martinez, Jean-Michel; Vantrepotte, Vincent; Anthony, Edward J.

    2016-04-01

    Fine-grained sediments supplied to the Ocean by the Amazon River and their transport under the influence of continental and oceanic forcing drives the geomorphic change along the 1500 km-long coast northward to the Orinoco River delta. The aim of this study is to give an encompassing view of the sediment dynamics in the shallow coastal waters from the Amazon River mouth to the Capes region (northern part of the Amapa region of Brazil and eastern part of French Guiana), where large mud banks are formed. Mud banks are the overarching features in the dynamics of the Amazon-Orinoco coast. They start migrating northward in the Capes region. Suspended Particulate Matter (SPM) concentrations were calculated from satellite products (MODIS Aqua and Terra) acquired over the period 2000-2013. The Census-X11 decomposition method used to discriminate short-term, seasonal and long-term time components of the SPM variability has rendered possible a robust analysis of the impact of continental and oceanic forcing. Continental forcing agents considered are the Amazon River water discharge, SPM concentration and sediment discharge. Oceanic forcing comprises modelled data of wind speed and direction, wave height and direction, and currents. A 150 km-long area of accretion is detected at Cabo Norte that may be linked with a reported increase in the river's sediment discharge concurrent with the satellite data study period. We also assess the rate of mud bank migration north of Cabo Norte, and highlight its variability. Although we confirm a 2 km y-1 migration rate, in agreement with other authors, we show that this velocity may be up to 5 km y-1 along the Cabo Orange region, and we highlight the effect of water discharge by major rivers debouching on this coastal mud belt in modulating such rates. Finally, we propose a refined sediment transport pattern map of the region based on our results and of previous studies in the area such as the AMASSEDS programme, and discuss the

  5. Inlet Geomorphology Evolution Work Unit

    Science.gov (United States)

    2015-10-30

    Coastal Inlets Research Program Inlet Geomorphology Evolution Work Unit The Inlet Geomorphology Evolution work unit of the CIRP develops methods...morphologic response. Presently, the primary tool of the Inlet Geomorphology Evolution work unit is the Sediment Mobility Tool (SMT), which allows the user

  6. Quaternary and Geomorphology.

    Science.gov (United States)

    Andrews, J. T.; Graf, W. L.

    1983-01-01

    Highlights conferences and meetings of organizations involved with quaternary geology and geomorphology, including International Union of Quaternary Research Conference held in Moscow. The impetus of a revision of "The Quaternary of the United States" resulted from this conference. Includes activities/aims of "Friends of the…

  7. Teaching Geomorphology at University

    Science.gov (United States)

    Sugden, David; Hamilton, Patrick

    1978-01-01

    Geomorphology courses in British universities emphasize the main landform/process systems rather than more abstract concepts. Recommends a more theoretical focus on fundamental geomorphic processes and methodological problems. Available from: Faculty of Modern Studies, Oxford Polytechnic, Headington, Oxford OX3 OBP, England. (Author/AV)

  8. Modeling surface water dynamics in the Amazon Basin using MOSART-Inundation v1.0: impacts of geomorphological parameters and river flow representation

    Science.gov (United States)

    Luo, Xiangyu; Li, Hong-Yi; Leung, L. Ruby; Tesfa, Teklu K.; Getirana, Augusto; Papa, Fabrice; Hess, Laura L.

    2017-03-01

    In the Amazon Basin, floodplain inundation is a key component of surface water dynamics and plays an important role in water, energy and carbon cycles. The Model for Scale Adaptive River Transport (MOSART) was extended with a macroscale inundation scheme for representing floodplain inundation. The extended model, named MOSART-Inundation, was used to simulate surface hydrology of the entire Amazon Basin. Previous hydrologic modeling studies in the Amazon Basin identified and addressed a few challenges in simulating surface hydrology of this basin, including uncertainties of floodplain topography and channel geometry, and the representation of river flow in reaches with mild slopes. This study further addressed four aspects of these challenges. First, the spatial variability of vegetation-caused biases embedded in the HydroSHEDS digital elevation model (DEM) data was explicitly addressed. A vegetation height map of about 1 km resolution and a land cover dataset of about 90 m resolution were used in a DEM correction procedure that resulted in an average elevation reduction of 13.2 m for the entire basin and led to evident changes in the floodplain topography. Second, basin-wide empirical formulae for channel cross-sectional dimensions were refined for various subregions to improve the representation of spatial variability in channel geometry. Third, the channel Manning roughness coefficient was allowed to vary with the channel depth, as the effect of riverbed resistance on river flow generally declines with increasing river size. Lastly, backwater effects were accounted for to better represent river flow in mild-slope reaches. The model was evaluated against in situ streamflow records and remotely sensed Envisat altimetry data and Global Inundation Extent from Multi-Satellites (GIEMS) inundation data. In a sensitivity study, seven simulations were compared to evaluate the impacts of the five modeling aspects addressed in this study. The comparisons showed that

  9. Electrical resistivity investigation of fluvial geomorphology to evaluate potential seepage conduits to agricultural lands along the San Joaquin River, Merced County, California, 2012–13

    Science.gov (United States)

    Groover, Krishangi D.; Burgess, Matthew K.; Howle, James F.; Phillips, Steven P.

    2017-02-08

    Increased flows in the San Joaquin River, part of the San Joaquin River Restoration Program, are designed to help restore fish populations. However, increased seepage losses could result from these higher restoration flows, which could exacerbate existing drainage problems in neighboring agricultural lands and potentially damage crops. Channel deposits of abandoned river meanders that are hydraulically connected to the river could act as seepage conduits, allowing rapid and widespread water-table rise during restoration flows. There is a need to identify the geometry and properties of these channel deposits to assess their role in potential increased seepage effects and to evaluate management alternatives for reducing seepage. Electrical and electromagnetic surface geophysical methods have provided a reliable proxy for lithology in studies of fluvial and hyporheic systems where a sufficient electrical contrast exists between deposits of differing grain size. In this study, direct-current (DC) resistivity was used to measure subsurface resistivity to identify channel deposits and to map their subsurface geometry. The efficacy of this method was assessed by using DC resistivity surveys collected along a reach of the San Joaquin River in Merced County, California, during the summers of 2012 and 2013, in conjunction with borings and associated measurements from a hydraulic profiling tool. Modeled DC resistivity data corresponded with data from cores, hand-auger samples, a hydraulic profiling tool, and aerial photographs, confirming that DC resistivity is effective for differentiating between silt and sand deposits in this setting. Modeled DC resistivity data provided detailed two-dimensional cross-sectional resistivity profiles to a depth of about 20 meters. The distribution of high-resistivity units in these profiles was used as a proxy for identifying areas of high hydraulic conductivity. These data were used subsequently to guide the location and depth of wells

  10. Geomorphologic specificities of selected sites for nuclear power plants in Czechoslovakia

    International Nuclear Information System (INIS)

    Kalvoda, J.; Demek, J.

    1991-01-01

    The contribution of geomorphology to the complex evaluation of properties of sites for the construction and operation of nuclear facilities is demonstrated. The unique manifestation of the present geodynamics at the Jaslovske Bohunice nuclear power plant locality and the spatial correlations of annals of the specific morphotectonic development of georeliefs of that nuclear power plant with the location of the epicentral earthquake zones are shown. The results of the geomorphological survey in the surroundings of the Temelin nuclear power plant construction site are described and a drawing is reproduced showing how the georelief of this locality divides into areas with different categories of occurrence of morpho-structural formations. For the Tetov locality, where the construction of a nuclear power plant is planned, the changes in the course of the Labe (Elbe) river which occurred in the Pleistocene are of importance in the assessment of the intensity of geodynamic processes. The geomorphological and geotectonic complexity of the planned Blahutovice nuclear power plant construction site is demonstrated. A drawing shows the morphotectonic situation in the surroundings of that construction site. (Z.S.). 4 figs

  11. Radioactivity in the Calcasieu River/Lake Complex

    International Nuclear Information System (INIS)

    Broussard, M.; Beck, J.N.

    1987-01-01

    Concentrations of natural and manmade radionuclides including 40 K, 137 Cs, 226 Ra, 228 Ac, and their decay products were measured in sediment and water samples. Gross alpha and gross beta activities were also determined in water samples. The levels of radioactivity were found to be low in all water samples, with a general increase of activity toward the brackish waters of the southern portion of the study area. The concentrations of uranium and thorium daughters found in sediment samples were found to be relatively constant across the study area. The concentration of 40 K was found to vary in a regular manner, with the lowest values found in the northern portion of the river/lake complex and highest values found at the southern stations. This suggests transport and deposition of potassium into the organic-rich sediments. The only manmade radionuclide found was 137 Cs which was deposited only in the top 15 to 20 cm of sediment and was uniformly distributed across the sample area

  12. Significance of beach geomorphology on fecal indicator bacteria levels.

    Science.gov (United States)

    Donahue, Allison; Feng, Zhixuan; Kelly, Elizabeth; Reniers, Ad; Solo-Gabriele, Helena M

    2017-08-15

    Large databases of fecal indicator bacteria (FIB) measurements are available for coastal waters. With the assistance of satellite imagery, we illustrated the power of assessing data for many sites by evaluating beach features such as geomorphology, distance from rivers and canals, presence of piers and causeways, and degree of urbanization coupled with the enterococci FIB database for the state of Florida. We found that beach geomorphology was the primary characteristic associated with enterococci levels that exceeded regulatory guidelines. Beaches in close proximity to marshes or within bays had higher enterococci exceedances in comparison to open coast beaches. For open coast beaches, greater enterococci exceedances were associated with nearby rivers and higher levels of urbanization. Piers and causeways had a minimal contribution, as their effect was often overwhelmed by beach geomorphology. Results can be used to understand the potential causes of elevated enterococci levels and to promote public health. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Tamarix, hydrology and fluvial geomorphology: Chapter 7

    Science.gov (United States)

    Auerbach, Daniel A.; Merritt, David M.; Shafroth, Patrick B.; Sher, Anna A; Quigley, Martin F.

    2013-01-01

    This chapter explores the impact of hydrology and fluvial geomorphology on the distribution and abundance of Tamarix as well as the reciprocal effects of Tamarix on hydrologic and geomorphic conditions. It examines whether flow-regime alteration favors Tamarix establishment over native species, and how Tamarix stands modify processes involved in the narrowing of river channels and the formation of floodplains. It begins with an overview of the basic geomorphic and hydrologic character of rivers in the western United States before analyzing how this setting has contributed to the regional success of Tamarix. It then considers the influence of Tamarix on the hydrogeomorphic form and function of rivers and concludes by discussing how a changing climate, vegetation management, and continued water-resource development affect the future role of Tamarix in these ecosystems.

  14. Geomorphology, acoustic backscatter, and processes in Santa Monica Bay from multibeam mapping.

    Science.gov (United States)

    Gardner, James V; Dartnell, Peter; Mayer, Larry A; Hughes Clarke, John E

    2003-01-01

    Santa Monica Bay was mapped in 1996 using a high-resolution multibeam system, providing the first substantial update of the submarine geomorphology since the initial compilation by Shepard and Emery [(1941) Geol. Soc. Amer. Spec. Paper 31]. The multibeam mapping generated not only high-resolution bathymetry, but also coregistered, calibrated acoustic backscatter at 95 kHz. The geomorphology has been subdivided into six provinces; shelf, marginal plateau, submarine canyon, basin slope, apron, and basin. The dimensions, gradients, and backscatter characteristics of each province is described and related to a combination of tectonics, climate, sea level, and sediment supply. Fluctuations of eustatic sea level have had a profound effect on the area; by periodically eroding the surface of Santa Monica plateau, extending the mouth of the Los Angeles River to various locations along the shelf break, and by connecting submarine canyons to rivers. A wetter glacial climate undoubtedly generated more sediment to the rivers that then transported the increased sediment load to the low-stand coastline and canyon heads. The trends of Santa Monica Canyon and several bathymetric highs suggest a complex tectonic stress field that has controlled the various segments. There is no geomorphic evidence to suggest Redondo Canyon is fault controlled. The San Pedro fault can be extended more than 30 km to the northwest by the alignment of a series of bathymetric highs and abrupt changes in direction of channel thalwegs.

  15. Geomorphologic characteristic of low-intermediate level radioactive waste disposal land candidate at Lemahabang area

    International Nuclear Information System (INIS)

    Sucipta

    1998-01-01

    Geomorphological aspect is a factor should be considered on land evaluation for radioactive wastes disposal purpose. The aspect is important because geomorphological factors contribute on hydrological and erosion condition of the land. The objective of the study is to characterize the geomorphological condition of the land, i.e. land form, geomorphological processes, rock type, soil, surface water, ground water, vegetation and land use. The study was conducted by descriptive analyses from literature study and field geomorphological method, with evaluation as well as developed for terrain analyses. The study area can be divided industry for land from units, I.e. tuff undulating unit (land use: plantation), coastal deposits plain unit, silty sand fluvial plain unit (land use: wet rice field) and unconsolidated sand beach deposits plain unit (opened land without vegetation). Hydrologically, the study area can be divided indus tri three small river stream area (RSA). Detailed description of geomorfological condition is showed by table and geomorphological map. (author)

  16. Geomorphosites and the history of geomorphology

    Science.gov (United States)

    Giusti, Christian

    2013-04-01

    of rivers, particularly in the Alps (e.g. Maigrauge dam and Sarine valley, Fribourg). The latter has left many sketchbooks preserved in a restricted repository at the Geographic Institute library in Paris, which are the illustrated part (e.g., The Châtelard Valley from Finhaut, Valais, Switzerland) of a huge archive of his theory of glacial erosion in alpine mountains. Both were scientific editors (with E. Chaix) of the first Atlas Photographique des Formes du Relief, published by Boissonas in Geneva, 1914. The presentation will focus on the scientific importance of some geomorphosites for the knowledge on the history of geomorphology and Earth sciences in general.

  17. An advanced modelling tool for simulating complex river systems.

    Science.gov (United States)

    Trancoso, Ana Rosa; Braunschweig, Frank; Chambel Leitão, Pedro; Obermann, Matthias; Neves, Ramiro

    2009-04-01

    The present paper describes MOHID River Network (MRN), a 1D hydrodynamic model for river networks as part of MOHID Water Modelling System, which is a modular system for the simulation of water bodies (hydrodynamics and water constituents). MRN is capable of simulating water quality in the aquatic and benthic phase and its development was especially focused on the reproduction of processes occurring in temporary river networks (flush events, pools formation, and transmission losses). Further, unlike many other models, it allows the quantification of settled materials at the channel bed also over periods when the river falls dry. These features are very important to secure mass conservation in highly varying flows of temporary rivers. The water quality models existing in MOHID are base on well-known ecological models, such as WASP and ERSEM, the latter allowing explicit parameterization of C, N, P, Si, and O cycles. MRN can be coupled to the basin model, MOHID Land, with computes runoff and porous media transport, allowing for the dynamic exchange of water and materials between the river and surroundings, or it can be used as a standalone model, receiving discharges at any specified nodes (ASCII files of time series with arbitrary time step). These features account for spatial gradients in precipitation which can be significant in Mediterranean-like basins. An interface has been already developed for SWAT basin model.

  18. Integrated Project Management Planning for the Deactivation of the Savannah River Site F-Canyon Complex

    Energy Technology Data Exchange (ETDEWEB)

    Clark, T.G.

    2000-12-01

    This paper explains the planning process that is being utilized by the Westinghouse Savannah River Company to take the F-Canyon Complex facilities from operations to a deactivated condition awaiting final decommissioning.

  19. Geomorphology and soil survey

    Science.gov (United States)

    Laura A. Murray; Bob Eppinette; John H. Thorp

    2000-01-01

    The Coosawhatchie River, through erosion and downcutting, carved a fluvial valley through the Wicomico and Pamlico marine terraces during the late Pleistocene-Holocene period. The floodplain is relatively small and immature compared to the major river systems of the South Carolina Lower Coastal Plain. Consequently, the classic geomorphic features of a larger fluvial...

  20. Socio-Hydrology of Channel Flows in Complex River Basins: Rivers, Canals, and Distributaries in Punjab, Pakistan

    Science.gov (United States)

    Wescoat, James L.; Siddiqi, Afreen; Muhammad, Abubakr

    2018-01-01

    This paper presents a socio-hydrologic analysis of channel flows in Punjab province of the Indus River basin in Pakistan. The Indus has undergone profound transformations, from large-scale canal irrigation in the mid-nineteenth century to partition and development of the international river basin in the mid-twentieth century, systems modeling in the late-twentieth century, and new technologies for discharge measurement and data analytics in the early twenty-first century. We address these processes through a socio-hydrologic framework that couples historical geographic and analytical methods at three levels of flow in the Punjab. The first level assesses Indus River inflows analysis from its origins in 1922 to the present. The second level shows how river inflows translate into 10-daily canal command deliveries that vary widely in their conformity with canal entitlements. The third level of analysis shows how new flow measurement technologies raise questions about the performance of established methods of water scheduling (warabandi) on local distributaries. We show how near real-time measurement sheds light on the efficiency and transparency of surface water management. These local socio-hydrologic changes have implications in turn for the larger scales of canal and river inflow management in complex river basins.

  1. The geomorphology of Ceres.

    Science.gov (United States)

    Buczkowski, D L; Schmidt, B E; Williams, D A; Mest, S C; Scully, J E C; Ermakov, A I; Preusker, F; Schenk, P; Otto, K A; Hiesinger, H; O'Brien, D; Marchi, S; Sizemore, H; Hughson, K; Chilton, H; Bland, M; Byrne, S; Schorghofer, N; Platz, T; Jaumann, R; Roatsch, T; Sykes, M V; Nathues, A; De Sanctis, M C; Raymond, C A; Russell, C T

    2016-09-02

    Analysis of Dawn spacecraft Framing Camera image data allows evaluation of the topography and geomorphology of features on the surface of Ceres. The dwarf planet is dominated by numerous craters, but other features are also common. Linear structures include both those associated with impact craters and those that do not appear to have any correlation to an impact event. Abundant lobate flows are identified, and numerous domical features are found at a range of scales. Features suggestive of near-surface ice, cryomagmatism, and cryovolcanism have been identified. Although spectroscopic analysis has currently detected surface water ice at only one location on Ceres, the identification of these potentially ice-related features suggests that there may be at least some ice in localized regions in the crust. Copyright © 2016, American Association for the Advancement of Science.

  2. Global Mega-geomorphology

    Science.gov (United States)

    Hayden, R. S. (Editor)

    1985-01-01

    The extension of space exploration to the Moon and to other planets has broadened the scope of geomorphology by providing information on landforms which have developed in environments that differ significantly in fundamental factors such as temperature, pressure and gravity from the environments in which Earth's landforms have been shaped. In some cases the landforming processes themselves appear to be significantly different than any found in the terrestrial environment. Some investigators have suggested that features observed on other planets, such as chaos terrian and labryinths on Mars, can help us understand Earth's early history better because they may have been formed by processes which were important in the early ages of Earth but have long ceased to be active here. Corresponding terrestrial landforms would have long since been altered or obliterated by subsequent activity.

  3. Advances in global mountain geomorphology

    Science.gov (United States)

    Slaymaker, Olav; Embleton-Hamann, Christine

    2018-05-01

    Three themes in global mountain geomorphology have been defined and reinforced over the past decade: (a) new ways of measuring, sensing, and analyzing mountain morphology; (b) a new emphasis on disconnectivity in mountain geomorphology; and (c) the emergence of concerns about the increasing influence of anthropogenic disturbance of the mountain geomorphic environment, especially in intertropical mountains where population densities are higher than in any other mountain region. Anthropogenically induced hydroclimate change increases geomorphic hazards and risks but also provides new opportunities for mountain landscape enhancement. Each theme is considered with respect to the distinctiveness of mountain geomorphology and in relation to important advances in research over the past decade. The traditional reliance on the high energy condition to define mountain geomorphology seems less important than the presence of unique mountain landforms and landscapes and the distinctive ways in which human activity and anthropogenically induced hydroclimate change are transforming mountain landscapes.

  4. Impacts of large dams on the complexity of suspended sediment dynamics in the Yangtze River

    Science.gov (United States)

    Wang, Yuankun; Rhoads, Bruce L.; Wang, Dong; Wu, Jichun; Zhang, Xiao

    2018-03-01

    The Yangtze River is one of the largest and most important rivers in the world. Over the past several decades, the natural sediment regime of the Yangtze River has been altered by the construction of dams. This paper uses multi-scale entropy analysis to ascertain the impacts of large dams on the complexity of high-frequency suspended sediment dynamics in the Yangtze River system, especially after impoundment of the Three Gorges Dam (TGD). In this study, the complexity of sediment dynamics is quantified by framing it within the context of entropy analysis of time series. Data on daily sediment loads for four stations located in the mainstem are analyzed for the past 60 years. The results indicate that dam construction has reduced the complexity of short-term (1-30 days) variation in sediment dynamics near the structures, but that complexity has actually increased farther downstream. This spatial pattern seems to reflect a filtering effect of the dams on the on the temporal pattern of sediment loads as well as decreased longitudinal connectivity of sediment transfer through the river system, resulting in downstream enhancement of the influence of local sediment inputs by tributaries on sediment dynamics. The TGD has had a substantial impact on the complexity of sediment series in the mainstem of the Yangtze River, especially after it became fully operational. This enhanced impact is attributed to the high trapping efficiency of this dam and its associated large reservoir. The sediment dynamics "signal" becomes more spatially variable after dam construction. This study demonstrates the spatial influence of dams on the high-frequency temporal complexity of sediment regimes and provides valuable information that can be used to guide environmental conservation of the Yangtze River.

  5. Current trends in geomorphological mapping

    Science.gov (United States)

    Seijmonsbergen, A. C.

    2012-04-01

    Geomorphological mapping is a world currently in motion, driven by technological advances and the availability of new high resolution data. As a consequence, classic (paper) geomorphological maps which were the standard for more than 50 years are rapidly being replaced by digital geomorphological information layers. This is witnessed by the following developments: 1. the conversion of classic paper maps into digital information layers, mainly performed in a digital mapping environment such as a Geographical Information System, 2. updating the location precision and the content of the converted maps, by adding more geomorphological details, taken from high resolution elevation data and/or high resolution image data, 3. (semi) automated extraction and classification of geomorphological features from digital elevation models, broadly separated into unsupervised and supervised classification techniques and 4. New digital visualization / cartographic techniques and reading interfaces. Newly digital geomorphological information layers can be based on manual digitization of polygons using DEMs and/or aerial photographs, or prepared through (semi) automated extraction and delineation of geomorphological features. DEMs are often used as basis to derive Land Surface Parameter information which is used as input for (un) supervised classification techniques. Especially when using high-res data, object-based classification is used as an alternative to traditional pixel-based classifications, to cluster grid cells into homogeneous objects, which can be classified as geomorphological features. Classic map content can also be used as training material for the supervised classification of geomorphological features. In the classification process, rule-based protocols, including expert-knowledge input, are used to map specific geomorphological features or entire landscapes. Current (semi) automated classification techniques are increasingly able to extract morphometric, hydrological

  6. Interaction of the sea breeze with a river breeze in an area of complex coastal heating

    Science.gov (United States)

    Zhong, Shiyuan; Takle, Eugene S.; Leone, John M., Jr.

    1991-01-01

    The interaction of the sea-breeze circulation with a river-breeze circulation in an area of complex coastal heating (east coast of Florida) was studied using a 3D finite-element mesoscale model. The model simulations are compared with temperature and wind fields observed on a typical fall day during the Kennedy Space Center Atmospheric Boundary Layer Experiment. The results from numerical experiments designed to isolate the effect of the river breeze indicate that the convergence in the sea-breeze front is suppressed when it passes over the cooler surface of the rivers.

  7. Sr isotope tracing of multiple water sources in a complex river system, Noteć River, central Poland

    Energy Technology Data Exchange (ETDEWEB)

    Zieliński, Mateusz, E-mail: mateusz.zielinski@amu.edu.pl [Institute of Geoecology and Geoinformation, Adam Mickiewicz University, Dzięgielowa 27, 61-680 Poznań (Poland); Dopieralska, Jolanta, E-mail: dopieralska@amu.edu.pl [Poznań Science and Technology Park, Adam Mickiewicz University Foundation, Rubież 46, 61-612 Poznań (Poland); Belka, Zdzislaw, E-mail: zbelka@amu.edu.pl [Isotope Laboratory, Adam Mickiewicz University, Dzięgielowa 27, 61-680 Poznań (Poland); Walczak, Aleksandra, E-mail: awalczak@amu.edu.pl [Isotope Laboratory, Adam Mickiewicz University, Dzięgielowa 27, 61-680 Poznań (Poland); Siepak, Marcin, E-mail: siep@amu.edu.pl [Institute of Geology, Adam Mickiewicz University, Maków Polnych 16, 61-606 Poznań (Poland); Jakubowicz, Michal, E-mail: mjakub@amu.edu.pl [Institute of Geoecology and Geoinformation, Adam Mickiewicz University, Dzięgielowa 27, 61-680 Poznań (Poland)

    2016-04-01

    Anthropogenic impact on surface waters and other elements in the environment was investigated in the Noteć River basin in central Poland. The approach was to trace changes in the Sr isotope composition ({sup 87}Sr/{sup 86}Sr) and concentration in space and time. Systematic sampling of the river water shows a very wide range of {sup 87}Sr/{sup 86}Sr ratios, from 0.7089 to 0.7127. This strong variation, however, is restricted to the upper course of the river, whereas the water in the lower course typically shows {sup 87}Sr/{sup 86}Sr values around 0.7104–0.7105. Variations in {sup 87}Sr/{sup 86}Sr are associated with a wide range of Sr concentrations, from 0.14 to 1.32 mg/L. We find that strong variations in {sup 87}Sr/{sup 86}Sr and Sr concentrations can be accounted for by mixing of two end-members: 1) atmospheric waters charged with Sr from the near-surface weathering and wash-out of Quaternary glaciogenic deposits, and 2) waters introduced into the river from an open pit lignite mine. The first reservoir is characterized by a low Sr content and high {sup 87}Sr/{sup 86}Sr ratios, whereas mine waters display opposite characteristics. Anthropogenic pollution is also induced by extensive use of fertilizers which constitute the third source of Sr in the environment. The study has an important implication for future archeological studies in the region. It shows that the present-day Sr isotope signatures of river water, flora and fauna cannot be used unambiguously to determine the “baseline” for bioavailable {sup 87}Sr/{sup 86}Sr in the past. - Highlights: • Sr isotopes fingerprint water sources and their interactions in a complex river system. • Mine waters and fertilizers are critical anthropogenic additions in the river water. • Limited usage of environmental isotopic data in archeological studies. • Sr budget of the river is dynamic and temporary.

  8. Clicking in shallow rivers: short-range echolocation of Irrawaddy and Ganges River dolphins in a shallow, acoustically complex habitat.

    Directory of Open Access Journals (Sweden)

    Frants H Jensen

    Full Text Available Toothed whales (Cetacea, odontoceti use biosonar to navigate their environment and to find and catch prey. All studied toothed whale species have evolved highly directional, high-amplitude ultrasonic clicks suited for long-range echolocation of prey in open water. Little is known about the biosonar signals of toothed whale species inhabiting freshwater habitats such as endangered river dolphins. To address the evolutionary pressures shaping the echolocation signal parameters of non-marine toothed whales, we investigated the biosonar source parameters of Ganges river dolphins (Platanista gangetica gangetica and Irrawaddy dolphins (Orcaella brevirostris within the river systems of the Sundarban mangrove forest. Both Ganges and Irrawaddy dolphins produced echolocation clicks with a high repetition rate and low source level compared to marine species. Irrawaddy dolphins, inhabiting coastal and riverine habitats, produced a mean source level of 195 dB (max 203 dB re 1 µPapp whereas Ganges river dolphins, living exclusively upriver, produced a mean source level of 184 dB (max 191 re 1 µPapp. These source levels are 1-2 orders of magnitude lower than those of similar sized marine delphinids and may reflect an adaptation to a shallow, acoustically complex freshwater habitat with high reverberation and acoustic clutter. The centroid frequency of Ganges river dolphin clicks are an octave lower than predicted from scaling, but with an estimated beamwidth comparable to that of porpoises. The unique bony maxillary crests found in the Platanista forehead may help achieve a higher directionality than expected using clicks nearly an octave lower than similar sized odontocetes.

  9. Geomorphological characterization of endorheic basins in northern Chile

    Science.gov (United States)

    Dorsaz, J.; Gironas, J. A.; Escauriaza, C. R.; Rinaldo, A.

    2011-12-01

    Quantitative geomorphology regroups a large number of interesting tools to characterize natural basins across scales. The application of these tools to several river basins allows the description and comparison of geomorphological properties at different spatial scales as oppose to more traditional descriptors that are typically applied at a single scale, meaning the catchment scale. Most of the recent research using these quantitative geomorphological tools has focused on open catchments and no specific attention has been given to endorheic basins, and the possibility of having particular features that distinguish them from exorheic catchments. The main objective of our study is to characterize endorheic basins and investigate whether these special geomorphological features can be identified. Because scaling invariance is a widely observed and relatively well quantified property of open basins, it provides a suitable tool to characterize differences between the geomorphology of closed and open basins. Our investigation focuses on three closed basins located in northern Chile which describe well the diversity in the geomorphology and geology of this arid region. Results show that endhoreic basins exhibit different slope-area and flow paths sinuosity regimes compared to those observed in open basins. These differences are in agreement with the particular self-similar behavior across spatial scales of the Euclidean length of subcatchments, as well as the Hack's law and Horton's ratios. These regimes imply different physical processes inside the channel network regardless of the basin area, and they seem to be related to the endorheic character of these basins. The analysis of the probability density functions of contributing areas and lengths to the lower region shows that the hypothesis of self-similarity can also be applied to closed basins. Theoretical expressions for these distributions were derived and validated by the data. Future research will focus on (1

  10. FLOODPLAIN-CHANNEL COMPLEX OF SMALL RIVER: ASSESSMENT OF CURRENT STATE, OPTIMIZATION MEASURES

    Directory of Open Access Journals (Sweden)

    Kovalchuk I.

    2016-05-01

    Full Text Available The article describes main methodological principles of geoecological assessment of riverbed-floodplain complex condition of one of the small rivers in Ukrainian Carpathians. According to our long-term field, cartographic, laboratory and remote sensing research, division of riverbed into homogeneous geoecological segments was made, as well as their standardization in accordance to the trends of unfavorable processes. Main reasons for deterioration of quality characteristics of channel-floodplain river complex were outlined; the role of natural and anthropogenic factors in deterioration of geoecological condition of the river and its floodplain complex was analyzed. Based on the assessment results it is possible to state that the condition of study segments of the Berezhnytsya river flood-plain and stream-way complex was marked as “excellent”, “good” and “satisfactory”. “Unsatisfactory” and “catastrophic” river and flood-plain condition has not been detected yet, although within Dashava urban settlement the river area condition is close to the “satisfactory” grade. The best situation is at the river head as human impact is minimized here and natural vegetation is preserved. Downstream we trace the tendency of condition worsening as anthropogenic load on the basin system and flood-plain and stream-way complex increases. Its negative impact is balanced by large forests, thus in segments limited by Banya Lysovytska village and Lotatnyky village the river and flood-plain condition is rated as “good”. So, downstream from the named village the value of such an important natural barrier as forest is reducing and anthropogenic load on the river significantly increases. The latter manifests in an intensive agricultural reclamation and housing development of flood-plains. Since degradation processes are rapidly developing over a considerable part of the Berezhnytsya river, negative changes are visible and only the study area

  11. Salt fluxes in a complex river mouth system of Portugal.

    Directory of Open Access Journals (Sweden)

    Nuno Vaz

    Full Text Available Measurements of velocity and salinity near the mouth and head of the Espinheiro channel (Ria de Aveiro lagoon, Portugal are used to study the local variation of physical water properties and to assess the balance, under steady conditions, between the seaward salt transport induced by river discharge and the landward dispersion induced by various mixing mechanisms. This assessment is made using data sampled during complete tidal cycles. Under the assumption that the estuarine tidal channel is laterally homogeneous and during moderate tidal periods (except for one survey, currents and salinity data were decomposed into various spatial and temporal means and their deviations. Near the channel's mouth, the main contributions to the salt transport are the terms due to freshwater discharge and the tidal correlation. Near the channel's head, this last term is less important than the density driven circulation, which is enhanced by the increase in freshwater discharge. The remaining terms, which are dependent on the deviations from the mean depth have a smaller role in the results of salt transport. The computed salt transport per unit width of a section perpendicular to the mean flow is in close agreement to the sum of the advective and dispersive terms (within or very close to 12%. An imbalance of the salt budget across the sections is observed for all the surveys. Considerations are made on how this approach can inform the management of hazardous contamination and how to use these results to best time the release of environmental flows during dry months.

  12. Geomorphological characterization of conservation agriculture

    Science.gov (United States)

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

    2017-04-01

    Soil water erosion is one of the major threats to soil resources throughout the world. Conventional agriculture has worsened the situation. Therefore, agriculture is facing multiple challenges: it has to produce more food to feed a growing population, and, on the other hand, safeguard natural resources adopting more sustainable production practices. In this perspective, more conservation-minded soil management practices should be taken to achieve an environmental sustainability of crop production. Indeed, conservation agriculture is considered to produce relevant environmental positive outcomes (e.g. reducing runoff and soil erosion, improving soil organic matter content and soil structure, and promoting biological activity). However, as mechanical weed control is limited or absent, in conservation agriculture, dependence on herbicides increases especially in the first years of transition from the conventional system. Consequently, also the risk of herbicide losses via runoff or adsorbed to eroded soil particles could be increased. To better analyse the complexity of soil water erosion and runoff processes in landscapes characterised by conservation agriculture, first, it is necessary to demonstrate if such different practices can significantly affect the surface morphology. Indeed, surface processes such erosion and runoff strongly depend on the shape of the surface. The questions are: are the lands treated with conservation and conventional agriculture different from each other regarding surface morphology? If so, can these differences provide a better understanding of hydrogeomorphic processes as the basis for a better and sustainable land management? To give an answer to these questions, we considered six study areas (three cultivated with no-tillage techniques, three with tillage techniques) in an experimental farm. High-resolution topography, derived from low-cost and fast photogrammetric techniques Structure-from-Motion (SfM), served as the basis to

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

    Science.gov (United States)

    Reynard, Emmanuel

    2016-04-01

    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

  14. The geomorphology of Southeast Kenya

    NARCIS (Netherlands)

    Oosterom, A.P.

    1988-01-01

    A geomorphological map of an area of 66 500 km 2 in the southeastern part of Kenya has been prepared. In the littoral zone eight major terrace levels occurring between the present shore and approximately 160 m +MSL have been described. Analysis of radiometric datings and

  15. Communicating Geomorphology. JGHE Annual Lecture

    Science.gov (United States)

    Brierley, Gary

    2009-01-01

    Communication strategies emphasize concerns for "content" (what is said) and "process" (the way things are said). Scientists have a responsibility to communicate the findings of their research, enhancing prospects that their insights can meaningfully inform management practice. When used effectively, principles from geomorphology provide critical…

  16. Recent Trends in Karst Geomorphology.

    Science.gov (United States)

    Palmer, Arthur N.

    1984-01-01

    Recent trends related to the karst processes and the evolution of karst landscapes are discussed. The hydrochemical processes responsible for the origin of karst are expanded on to illustrate the present scope of karst studies. These geomorphological studies are combined with concepts and techniques from hydraulics, chemistry, and mathematics. (JN)

  17. Urban geomorphological heritage - A new field of research

    Science.gov (United States)

    Reynard, Emmanuel; Pica, Alessia; Coratza, Paola

    2017-04-01

    Urbanization is one of the major challenges that the world faces. In 2015, 54% of the world population was living in urban areas and in some countries this percentage is close to 100% (Singapore 100%; Qatar 99%; Belgium 98%). In several parts of the world annual urbanization rates exceed 5% (e.g. Oman 8.54%; Rwanda 6.43%; Burkina Faso 5.87%), which means that urban sprawl is a widespread phenomenon. Urbanization and correlated infrastructure building highly impact and sometimes completely destroy natural landforms. Geomorphological heritage research has traditionally focused on rural or natural regions, in particular protected areas (nature parks, geoparks). We consider that urban areas, which have been poorly investigated until now, are particularly interesting in a geomorphological heritage point of view for almost three reasons: (i) The geomorphological context (site) of some cities is part of their "image" and their fame (e.g. the sugarloaf of Rio de Janeiro); (ii) Urban sprawl often interacts with landforms, which addresses the challenge of geoheritage protection in fast urbanizing areas; (iii) Cities are often tourist destinations, which creates a potential for a geotourist promotion of their geomorphological heritage. This study addresses the main challenges research on geomorphological heritage is facing in urban contexts: (i) the complex interrelationships between natural landforms and urban forms; (ii) the partial or total invisibility of landforms and sediments that are covered or destroyed by urban infrastructures; (iii) man-made landforms as part of urban geomorphological heritage; (iv) the suitability of some landforms (valleys, gullies, mounts) for specific urban uses; (v) the geomorphic constraints of landforms on urban development; and (vi) the importance of some landforms for the urban landscape and the image of the cities. To address these challenges a methodological framework is proposed, which combines: (i) the geomorphological analysis of the

  18. Geomorphology of New England

    Science.gov (United States)

    Denny, C.S.

    1982-01-01

    Widely scattered terrestrial deposits of Cretaceous or Tertiary age and extensive nearshore and fluvial Coastal Plain deposits now largely beneath the sea indicate that the New England region has been above sea level during and since the Late Cretaceous. Estimates of rates of erosion based on sediment load in rivers and on volume of sediments in the Coastal Plain suggest that if the New England highlands had not been uplifted in the Miocene, the area would now be largely a lowland. If the estimated rates of erosion and uplift are of the right order of magnitude, then it is extremely unlikely that any part of the present landscape dates back before Miocene time. The only exception would be lowlands eroded in the early Mesozoic, later buried beneath Mesozoic and Cenozoic deposits, and exhumed by stream and glacial erosion during the later Cenozoic. Many of the rocks in the New England highlands are similar to those that underlie the Piedmont province in the central and southern Appalachians, where the relief over large areas is much less than in the highlands of New England. These comparisons suggest that the New England highlands have been upwarped in late Cenozoic time. The uplift took place in the Miocene and may have continued into the Quaternary. The New England landscape is primarily controlled by the underlying bedrock. Erosion and deposition during the Quaternary, related in large part to glaciation, have produced only minor changes in drainage and in topography. Shale and graywacke of Ordovician, Cambrian, and Proterozoic age forming the Taconic highlands, and akalic plutonic rocks of Mesozoic age are all highland makers. Sandstone and shale of Jurassic and Triassic age, similar rocks of Carboniferous age, and dolomite, limestone, and shale of Ordovician and Cambrian age commonly underlie lowlands. High-grade metapelites are more resistant than similar schists of low metamorphic grade and form the highest mountains in New England. Feldspathic rocks tend to

  19. A geologic approach to field methods in fluvial geomorphology

    Science.gov (United States)

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

    2014-01-01

    A geologic approach to field methods in fluvial geomorphology is useful for understanding causes and consequences of past, present, and possible future perturbations in river behavior and floodplain dynamics. Field methods include characterizing river planform and morphology changes and floodplain sedimentary sequences over long periods of time along a longitudinal river continuum. Techniques include topographic and bathymetric surveying of fluvial landforms in valley bottoms and describing floodplain sedimentary sequences through coring, trenching, and examining pits and exposures. Historical sediment budgets that include floodplain sedimentary records can characterize past and present sources and sinks of sediment along a longitudinal river continuum. Describing paleochannels and floodplain vertical accretion deposits, estimating long-term sedimentation rates, and constructing historical sediment budgets can assist in management of aquatic resources, habitat, sedimentation, and flooding issues.

  20. 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

    2016-03-01

    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.

  1. Re-meandering of lowland streams: will disobeying the laws of geomorphology have ecological consequences?

    Science.gov (United States)

    Pedersen, Morten Lauge; Kristensen, Klaus Kevin; Friberg, Nikolai

    2014-01-01

    We evaluated the restoration of physical habitats and its influence on macroinvertebrate community structure in 18 Danish lowland streams comprising six restored streams, six streams with little physical alteration and six channelized streams. We hypothesized that physical habitats and macroinvertebrate communities of restored streams would resemble those of natural streams, while those of the channelized streams would differ from both restored and near-natural streams. Physical habitats were surveyed for substrate composition, depth, width and current velocity. Macroinvertebrates were sampled along 100 m reaches in each stream, in edge habitats and in riffle/run habitats located in the center of the stream. Restoration significantly altered the physical conditions and affected the interactions between stream habitat heterogeneity and macroinvertebrate diversity. The substrate in the restored streams was dominated by pebble, whereas the substrate in the channelized and natural streams was dominated by sand. In the natural streams a relationship was identified between slope and pebble/gravel coverage, indicating a coupling of energy and substrate characteristics. Such a relationship did not occur in the channelized or in the restored streams where placement of large amounts of pebble/gravel distorted the natural relationship. The analyses revealed, a direct link between substrate heterogeneity and macroinvertebrate diversity in the natural streams. A similar relationship was not found in either the channelized or the restored streams, which we attribute to a de-coupling of the natural relationship between benthic community diversity and physical habitat diversity. Our study results suggest that restoration schemes should aim at restoring the natural physical structural complexity in the streams and at the same time enhance the possibility of re-generating the natural geomorphological processes sustaining the habitats in streams and rivers. Documentation of

  2. Understanding the Complexities of Communicating Management Decisions on the Subsistence Use of Yukon River Salmon

    Science.gov (United States)

    Brooks, J. F.; Trainor, S.

    2017-12-01

    Over 20,000 residents in Alaska and Yukon Territory rely upon the Yukon River to provide them harvests of Pacific salmon each year. Salmon are a highly valued food resource and the practice of salmon fishing along the Yukon is deep rooted in local cultures and traditions. Potential future impacts of climate change on the health of Yukon River salmon stocks could be significant. Collaborative managerial processes which incorporate the viewpoints of subsistence stakeholders will be crucial in enabling communities and managerial institutions to adapt and manage these impacts. However, the massive extent of the Yukon River makes it difficult for communities rich with highly localized knowledge to situate themselves within a drainage-wide context of resource availability, and to fully understand the implications that management decisions may have for their harvest. Differences in salmon availability and abundance between the upper and lower Yukon, commercial vs. subsistence fishery interests, and enforcement of the international Pacific Salmon Treaty further complicate understanding and makes the topic of salmon as a subsistence resource a highly contentious issue. A map which synthesizes the presence and absence of Pacific salmon throughout the entire Yukon River drainage was requested by both subsistence fishers and natural resource managers in Alaska in order to help facilitate productive conversations about salmon management decisions. Interviews with Alaskan stakeholders with managerial, biological, and subsistence harvest backgrounds were carried out and a literature review was conducted in order to understand what such a map should and could accomplish. During the research process, numerous data gaps concerning the distribution of salmon along the Yukon River were discovered, and insights about the complexities involved in translating science when it is situated within a charged political, economic, and cultural context were revealed. Preliminary maps depicting

  3. Rangeland management and fluvial geomorphology in northern Tanzania

    Science.gov (United States)

    Miller, Brian W.; Doyle, Martin W.

    2014-01-01

    Researchers have independently documented the effects of land use on rivers and threats to river management institutions, but the relationship between changes in institutional context and river condition is not well described. This study assesses the connections between resource management institutions, land use, and rivers by integrating social science, geospatial analysis, and geomorphology. In particular, we measured hydraulic geometry, sediment size distributions, and estimated sediment yield for four rivers in northern Tanzania and conducted semistructured interviews that assessed corresponding resource management institutions. Communities managed rivers through both customary (traditional, nonstate) and government institutions, but the differences in the resource management policies and practices of the study rivers themselves were fairly subtle. Clearer differences were found at broader scales; the four watersheds exhibited substantial differences in land cover change and sediment yield associated with the location of settlements, roadways, and cultivation. Unexpectedly, these recent land use changes did not initiate a geomorphic response in rivers. The long history of grazing by domestic and wild ungulates may have influenced water and sediment supplies such that river channel dimensions are more resistant to changes in land use than other systems or have already adjusted to predominant changes in boundary conditions. This would suggest that not all rivers will have the anticipated responses to contemporary land use changes because of antecedent land use patterns; over long time scales (centuries to millennia), the presence of grazers may actually increase the ability of rivers to withstand changes in land use. Our findings point to a need for further interdisciplinary study of dryland rivers and their shifts between system states, especially in areas with a long history of grazing, relatively recent changes in land use, and a dynamic social and

  4. Rangeland management and fluvial geomorphology in northern Tanzania.

    Science.gov (United States)

    Miller, Brian W; Doyle, Martin W

    2014-06-01

    Researchers have independently documented the effects of land use on rivers and threats to river management institutions, but the relationship between changes in institutional context and river condition is not well described. This study assesses the connections between resource management institutions, land use, and rivers by integrating social science, geospatial analysis, and geomorphology. In particular, we measured hydraulic geometry, sediment size distributions, and estimated sediment yield for four rivers in northern Tanzania and conducted semistructured interviews that assessed corresponding resource management institutions. Communities managed rivers through both customary (traditional, nonstate) and government institutions, but the differences in the resource management policies and practices of the study rivers themselves were fairly subtle. Clearer differences were found at broader scales; the four watersheds exhibited substantial differences in land cover change and sediment yield associated with the location of settlements, roadways, and cultivation. Unexpectedly, these recent land use changes did not initiate a geomorphic response in rivers. The long history of grazing by domestic and wild ungulates may have influenced water and sediment supplies such that river channel dimensions are more resistant to changes in land use than other systems or have already adjusted to predominant changes in boundary conditions. This would suggest that not all rivers will have the anticipated responses to contemporary land use changes because of antecedent land use patterns; over long time scales (centuries to millennia), the presence of grazers may actually increase the ability of rivers to withstand changes in land use. Our findings point to a need for further interdisciplinary study of dryland rivers and their shifts between system states, especially in areas with a long history of grazing, relatively recent changes in land use, and a dynamic social and

  5. Theorising complex water governance in Africa: the case of the proposed Epupa Dam on the Kunene River

    CSIR Research Space (South Africa)

    Meissner, Richard

    2014-04-01

    Full Text Available Various multi-dimensional governance models have been suggested by scholars and policy makers alike as suitable conceptual lenses through which to view the complexity of water governance, particularly in international river basins. While...

  6. Quantifying the performance of automated GIS-based geomorphological approaches for riparian zone delineation using digital elevation models

    Directory of Open Access Journals (Sweden)

    D. Fernández

    2012-10-01

    Full Text Available Riparian zone delineation is a central issue for managing rivers and adjacent areas; 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 usually only available for populated areas at risk of flooding. In this work we created several floodplain surfaces by means of two different GIS-based geomorphological approaches using digital elevation models (DEMs, in an attempt to find hydrologically meaningful potential riparian zones for river networks at the river basin scale. Objective quantification of the performance of the two geomorphologic models is provided by analysing coinciding and exceeding areas with respect to the 50-yr flood surface in different river geomorphological types.

  7. Geomorphology of Minnesota - Isolated Landform Structures

    Data.gov (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...

  8. Hydropolitical Complexes and Asymmetrical Power: Conflict, Cooperation, and Governance of International River Systems

    Directory of Open Access Journals (Sweden)

    Jenny R. Kehl

    2015-08-01

    Full Text Available Hydropolitical complexes are emerging to negotiate water-sharing policies that promote politicalstability, regional security, economic prosperity, and environmental sustainability. Yet interstatedisputes are occurring within most hydropolitical complexes, and weak riparians are oftencoerced to agree to water-sharing policies that adversely affect them. This research examines thestrategies weak riparians use to assert leverage in international river basins with asymmetricalpower, and the success of those strategies in achieving cooperation versus conflict. Grounded inthe theoretical framework of hydro hegemony, hard power, and soft power, this study uses crossnational analysis to test the effects of geographic, military, political, economic, technological,and external influence on water governance in eight international river systems. The resultsdemonstrate that weak riparians mobilize the assets and capacities of external actors, such asdonor countries and the World Bank, to increase their leverage within hydropolitical complexes.The study finds that strategies to balance hard power are largely ineffective; they fail to achievecooperative water-sharing arrangements and often exacerbate conflict. In contrast, strategies tobalance economic power and soft power, such as market access and political legitimacy, aremore successful in promoting cooperation and preventing conflict in hydropolitical complexes.

  9. Process and form in geomorphology

    National Research Council Canada - National Science Library

    Stoddart, D. R

    1997-01-01

    ... the world. The book is in two parts. The first presents state-of-the-art reports on fluvial, tectonic and climatic geomorphology by leading experts in their fields, all Chorley's colleagues and students. The second brings revisionary views to many aspects of the history of the discipline, on which Chorley is the world authority. Together they present not only new views on the landforms of the world but also incisive insights into how we have made sense of the environment around us from the early eighteenth centu...

  10. Highlighting landslides and other geomorphological features using sediment connectivity maps

    Science.gov (United States)

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

    2016-04-01

    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

  11. Geomorphology: the Shock of the Familiar

    Science.gov (United States)

    Dietrich, W. E.

    2008-12-01

    Everyone experiences landscapes and has a sense about how they work: water runs down hill, it erodes and carries sediments, and that's about it, right? Introductory earth science text books are uniformly qualitative about the field, and leave one with little sense of wonder, and certainly not "shock". But four shocks occur if one peels away the first impressions. First, landscapes are surprisingly similar: the same forms are repeated in virtually all environments, including under the ocean and on other planets. Second, we lack theory and mechanistic observations to answer many simple first-order questions, e.g. what controls the width of a river, how does rock type control hillslope form and erosion rate, or, is there a topographic signature of life. Third, there are unexpected connections between surface erosion, deep earth processes, and climate. And fourth, the field itself, despite having been a subject of study for well over 100 years, is currently experiencing a revolution of ideas and discoveries through new tools, observatories, centers, journals, books, contributions of researchers from other disciplines, and from a significant hiring of young researchers in geomorphology. Deep messages await discovery in the simple landforms surrounding us.

  12. Evaluating the use of augmented reality to support undergraduate student learning in geomorphology

    Science.gov (United States)

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

    2016-12-01

    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.

  13. Kinds and problems of geomorphological explanation

    Science.gov (United States)

    Cox, Nicholas J.

    2007-07-01

    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.

  14. Geomorphological applications of environmental radionuclides

    International Nuclear Information System (INIS)

    Quine, T.A.; Walling, D.

    1998-01-01

    Geomorphologists have shown increasing interest in environmental radionuclides since pioneering studies by Ritchie and McHenry in the USA and Campbell, Longmore and Loughran in Australia. Environmental radionuclides have attracted this interest because they provide geomorphologists with the means to trace sediment movement within the landscape. They, therefore, facilitate investigation of subjects at the core of geomorphology, namely the rates and patterns of landscape change. Most attention has been focussed on the artificial radionuclide caesium-137 ( 137 Cs) but more recently potential applications of the natural radionuclides lead-210 ( 210 Pb) and beryllium-7( 7 Be) have been investigated (Walling et al., 1995; Wallbrink and Murray, 1996a, 1996b). The origin, characteristics and applications of these radionuclides are summarised. These radionuclides are of value as sediment tracers because of three important characteristics: a strong affinity for sediment; a global distribution and the possibility of measurement at low concentration. Geomorphological applications of environmental radionuclides provide unique access to detailed qualitative data concerning landscape change over a range of timescales

  15. Architecture and development of a multi-stage Baiyun submarine slide complex in the Pearl River Canyon, northern South China Sea

    Science.gov (United States)

    Wang, Lei; Wu, Shi-Guo; Li, Qing-Ping; Wang, Da-Wei; Fu, Shao-Ying

    2014-08-01

    The Baiyun submarine slide complex (BSSC) along the Pearl River Canyon of the northern South China Sea has been imaged by multibeam bathymetry and 2D/3D seismic data. By means of maximum likelihood classification with slope aspect and gradient as inputs, the BSSC is subdivided into four domains, denoted as slide area I, II, III and IV. Slide area I is surrounded by cliffs on three sides and has been intensely reshaped by turbidity currents generated by other kinds of mass movement outside the area; slide area II incorporates a shield volcano with a diameter of approximately 10 km and unconfined slides possibly resulting from the toe collapse of inter-canyon ridges; slide area III is dominated by repeated slides that mainly originated from cliffs constituting the eastern boundary of the BSSC; slide area IV is distinguished by a conical seamount with a diameter of 6.5 km and a height of 375 m, and two slides probably having a common source that are separated from each other by a suite of residual strata. The BSSC is interpreted to be composed of numerous slide events, which occurred in the period from 10.5 to 5.5 Ma BP. Six specific factors may have contributed to the development of the BSSC, i.e., gas hydrate dissociation, gas-bearing sediments, submarine volcanic activity, seismicity, sedimentation rate and seafloor geomorphology. A 2D conceptual geological model combining these factors is proposed as a plausible mechanism explaining the formation of the BSSC. However, the BSSC may also have been affected by the Dongsha event (10 Ma BP) as an overriding factor.

  16. A summary of ecological investigations at the burial ground complex, Savannah River Site - 1994

    Energy Technology Data Exchange (ETDEWEB)

    Friday, G.P.; Hartman, G.D.; Mackey, H.E. Jr.; Riley, R.S.; Roach, J.L.; Specht, W.L.; Westbury, H.M.; Wike, L.D.

    1994-11-01

    This report summarizes the results of three ecological investigations that were conducted in 1994 at the Burial Ground Complex (BGC) at the Savannah River Site (SRS). The three topics of study included remote sensing, aquatic toxicity testing, and qualitative surveys of herpetofauna and small mammals. Interim reports from each investigation are included in the appendices (A, B, and C). The objectives of the remote sensing effort were to compile historical aerial photography of the BGC and to develop a land use/cover map of the complex using recent aerial imagery. The goal of the aquatic toxicity testing was to determine if surface waters were toxic to aquatic biota whereas the objectives of the vertebrate surveys were to identify the species diversity and relative abundances of amphibians, reptiles, and small mammals inhabiting the study area.

  17. A summary of ecological investigations at the burial ground complex, Savannah River Site - 1994

    International Nuclear Information System (INIS)

    Friday, G.P.; Hartman, G.D.; Mackey, H.E. Jr.; Riley, R.S.; Roach, J.L.; Specht, W.L.; Westbury, H.M.; Wike, L.D.

    1994-11-01

    This report summarizes the results of three ecological investigations that were conducted in 1994 at the Burial Ground Complex (BGC) at the Savannah River Site (SRS). The three topics of study included remote sensing, aquatic toxicity testing, and qualitative surveys of herpetofauna and small mammals. Interim reports from each investigation are included in the appendices (A, B, and C). The objectives of the remote sensing effort were to compile historical aerial photography of the BGC and to develop a land use/cover map of the complex using recent aerial imagery. The goal of the aquatic toxicity testing was to determine if surface waters were toxic to aquatic biota whereas the objectives of the vertebrate surveys were to identify the species diversity and relative abundances of amphibians, reptiles, and small mammals inhabiting the study area

  18. Organically complexed copper, zinc, and chelating agents in the rivers of Western Puerto Rico

    International Nuclear Information System (INIS)

    Montgomery, J.R.; Echevarria, J.E.

    1975-01-01

    The method for determining soluble chelators gives their concentration in copper-equivalent chelating capacity units in fresh or slightly brackish (less than 3 percent salinity) water. The mean concentration of chelators in the Rio Guanajibo for December 1973 and January 1974 was 0.4 mg of copper per liter of water (N = 21, SD = 0.2) and for February 1974, 0.9 mg/liter (N = 8, SD = 0.4). The combined mean for the Rio Anasco and Culebrinas was 0.5 mg/liter (N = 7, SD = 0.4) in January and February 1974. The mean concentration of ionic copper was 0.5 μg/liter (N = 7, SD = 0.6) and of ionic zinc, 0.2 μg/liter (N = 8, SD = 0.1) in the Rio Guanajibo from November 1972 to February 1973. The concentration of organically bound copper was 0.3 μ/liter (N = 7, SD = 0.2) and that of organically bound zinc was 0.6 μg/liter (N = 8, SD = 0.6); this indicates that there was more than a sufficient quantity of chelator available in the river to complex all the soluble copper. The presence of a high ratio of Ca 2+ to Cu 2+ probably prevents the formation of larger concentrations of organically complexed copper. The mean concentration of chelating agents in the Guanajibo River seems to be directly related to the increased organic input from municipalities and a sugar mill. The concentration of chelators in tropical rivers appears to be higher than that found in Canadian lakes. The mean concentration for particulate organic carbon (POC) was 3653 μg atoms/liter (SD = 3653, N = 29). The dissolved reactive phosphate (DRP) ranged from a mean of 1.1 μg atom/liter. No significant correlation could be found between POC, DRP, and the concentration of chelators

  19. Quarrying: an anthropogenic geomorphological approach

    International Nuclear Information System (INIS)

    David, L.

    2008-01-01

    The study intends to give an introduction to the significance of quarrying from the point of view of anthropogenic geomorphology, indicating the level of surface forming due to the mining of mineral raw materials. The significance of this topic is supported by the existence of the so-called 'mining landscapes' that emerged since to the 19 th century. Authors focus on the geomorphic impact of quarrying with special emphasis on factors influencing its spatial distribution, as well as on the characteristics and classification of surface features produced by quarrying, providing an overview of the most important excavated and accumulated forms and form components, on the macro, meso and micro scales. Finally, international and Hungarian case studies illustrate some aspects of the opening and after-use of mining sites in order to observe how abandoned quarries can be turned into 'environmental values', and used as possible sites for exhibitions or for regional and tourism development projects. (author)

  20. Geomorphological hazards and environmental impact: Assessment and mapping

    Science.gov (United States)

    Panizza, Mario

    In five sections the author develops the methods for the integration of geomorphological concepts into Environmental Impact and Mapping. The first section introduces the concepts of Impact and Risk through the relationships between Geomorphological Environment and Anthropical Element. The second section proposes a methodology for the determination of Geomorphological Hazard and the identification of Geomorphological Risk. The third section synthesizes the procedure for the compilation of a Geomorphological Hazards Map. The fourth section outlines the concepts of Geomorphological Resource Assessment for the analysis of the Environmental Impact. The fifth section considers the contribution of geomorphological studies and mapping in the procedure for Environmental Impact Assessment.

  1. Fluvial biogeomorphology in the Anthropocene: Managing rivers and managing landscapes.

    Science.gov (United States)

    Viles, Heather

    2015-04-01

    Biogeomorphology considers the many, and often complex, interactions between ecological and geomorphological processes. The concept of the Anthropocene deserves greater attention by scientists working on biogeomorphology, as will be demonstrated in this talk though a focus on fluvial environments. Rivers and river systems have been the subject of long-term human interference and management across the world, often in the form of direct manipulation of biogeomorphic interactions. Up to the present three broadly-defined phases of the Anthropocene can be identified - the Palaeoanthropocene, the Industrial Revolution and the Great Acceleration. Each of these broad phases of the Anthropocene has different implications for fluvial biogeomorphology and river management. The nature and dynamics of tufa-depositing systems provide good examples of the differing Anthropocene situations and will be focused on in this talk. We may now be entering a fourth phase of the Anthropocene called 'Earth system stewardship'. In terms of better understanding and managing the biogeomorphic interactions within rivers in such a phase, an improved conceptualisation of the Anthropocene and the complex web of interactions between human, ecological and geomorphological processes is needed.

  2. Appraisal of geomorphology of the Goa coast

    Digital Repository Service at National Institute of Oceanography (India)

    Wagle, B.G.; Kunte, P.D.

    The National Institute of Oceanography is carrying out a comprehensive geological and geophysical survey of the continental margin of India. As a part of this project, a geomorphologic study of the coastal area was carried to understand...

  3. Stream Tables and Watershed Geomorphology Education.

    Science.gov (United States)

    Lillquist, Karl D.; Kinner, Patricia W.

    2002-01-01

    Reviews copious stream tables and provides a watershed approach to stream table exercises. Results suggest that this approach to learning the concepts of fluvial geomorphology is effective. (Contains 39 references.) (DDR)

  4. Using Miniature Landforms in Teaching Geomorphology.

    Science.gov (United States)

    Petersen, James F.

    1986-01-01

    This paper explores the uses of true landform miniatures and small-scale analogues and suggests ways to teach geomorphological concepts using small-scale relief features as illustrative examples. (JDH)

  5. Geomorphology in North American Geology Departments, 1971

    Science.gov (United States)

    White, Sidney E.; Malcolm, Marshall D.

    1972-01-01

    Presents results of a 1970-71 survey of 350 geomorphologists and geology departments to determine what sort of geomorphology is being taught in the colleges and universities of the United States and Canada. (PR)

  6. A dynamic simulation model of the Savannah River Site high level waste complex

    International Nuclear Information System (INIS)

    Gregory, M.V.; Aull, J.E.; Dimenna, R.A.

    1994-01-01

    A detailed, dynamic simulation entire high level radioactive waste complex at the Savannah River Site has been developed using SPEEDUP(tm) software. The model represents mass transfer, evaporation, precipitation, sludge washing, effluent treatment, and vitrification unit operation processes through the solution of 7800 coupled differential and algebraic equations. Twenty-seven discrete chemical constituents are tracked through the unit operations. The simultaneous simultaneous simulation of concurrent batch and continuous processes is achieved by several novel, customized SPEEDUP(tm) algorithms. Due to the model's computational burden, a high-end work station is required: simulation of a years operation of the complex requires approximately three CPU hours on an IBM RS/6000 Model 590 processor. The model will be used to develop optimal high level waste (HLW) processing strategies over a thirty year time horizon. It will be employed to better understand the dynamic inter-relationships between different HLW unit operations, and to suggest strategies that will maximize available working tank space during the early years of operation and minimize overall waste processing cost over the long-term history of the complex. Model validation runs are currently underway with comparisons against actual plant operating data providing an excellent match

  7. Geomorphology Drives Amphibian Beta Diversity in Atlantic Forest Lowlands of Southeastern Brazil.

    Directory of Open Access Journals (Sweden)

    Amom Mendes Luiz

    Full Text Available Beta diversity patterns are the outcome of multiple processes operating at different scales. Amphibian assemblages seem to be affected by contemporary climate and dispersal-based processes. However, historical processes involved in present patterns of beta diversity remain poorly understood. We assess and disentangle geomorphological, climatic and spatial drivers of amphibian beta diversity in coastal lowlands of the Atlantic Forest, southeastern Brazil. We tested the hypothesis that geomorphological factors are more important in structuring anuran beta diversity than climatic and spatial factors. We obtained species composition via field survey (N = 766 individuals, museum specimens (N = 9,730 and literature records (N = 4,763. Sampling area was divided in four spatially explicit geomorphological units, representing historical predictors. Climatic descriptors were represented by the first two axis of a Principal Component Analysis. Spatial predictors in different spatial scales were described by Moran Eigenvector Maps. Redundancy Analysis was implemented to partition the explained variation of species composition by geomorphological, climatic and spatial predictors. Moreover, spatial autocorrelation analyses were used to test neutral theory predictions. Beta diversity was spatially structured in broader scales. Shared fraction between climatic and geomorphological variables was an important predictor of species composition (13%, as well as broad scale spatial predictors (13%. However, geomorphological variables alone were the most important predictor of beta diversity (42%. Historical factors related to geomorphology must have played a crucial role in structuring amphibian beta diversity. The complex relationships between geomorphological history and climatic gradients generated by the Serra do Mar Precambrian basements were also important. We highlight the importance of combining spatially explicit historical and contemporary predictors for

  8. Geomorphology Drives Amphibian Beta Diversity in Atlantic Forest Lowlands of Southeastern Brazil.

    Science.gov (United States)

    Luiz, Amom Mendes; Leão-Pires, Thiago Augusto; Sawaya, Ricardo J

    2016-01-01

    Beta diversity patterns are the outcome of multiple processes operating at different scales. Amphibian assemblages seem to be affected by contemporary climate and dispersal-based processes. However, historical processes involved in present patterns of beta diversity remain poorly understood. We assess and disentangle geomorphological, climatic and spatial drivers of amphibian beta diversity in coastal lowlands of the Atlantic Forest, southeastern Brazil. We tested the hypothesis that geomorphological factors are more important in structuring anuran beta diversity than climatic and spatial factors. We obtained species composition via field survey (N = 766 individuals), museum specimens (N = 9,730) and literature records (N = 4,763). Sampling area was divided in four spatially explicit geomorphological units, representing historical predictors. Climatic descriptors were represented by the first two axis of a Principal Component Analysis. Spatial predictors in different spatial scales were described by Moran Eigenvector Maps. Redundancy Analysis was implemented to partition the explained variation of species composition by geomorphological, climatic and spatial predictors. Moreover, spatial autocorrelation analyses were used to test neutral theory predictions. Beta diversity was spatially structured in broader scales. Shared fraction between climatic and geomorphological variables was an important predictor of species composition (13%), as well as broad scale spatial predictors (13%). However, geomorphological variables alone were the most important predictor of beta diversity (42%). Historical factors related to geomorphology must have played a crucial role in structuring amphibian beta diversity. The complex relationships between geomorphological history and climatic gradients generated by the Serra do Mar Precambrian basements were also important. We highlight the importance of combining spatially explicit historical and contemporary predictors for understanding

  9. Today's sediment budget of the Rhine River channel, focusing on the Upper Rhine Graben and Rhenish Massif

    NARCIS (Netherlands)

    Frings, Roy M.; Gehres, Nicole; Promny, Markus; Middelkoop, Hans; Schüttrumpf, Holger; Vollmer, Stefan

    2014-01-01

    The river bed of the Rhine River is subject to severe erosion and sedimentation. Such high geomorphological process rates are unwanted for economical, ecological, and safety reasons. The objectives of this study were (1) to quantify the geomorphological development of the Rhine River between 1985

  10. Collection methods, data compilation, and lessons learned from a study of stream geomorphology associated with riparian cattle grazing along the Fever River, University of Wisconsin- Platteville Pioneer Farm, Wisconsin, 2004–11

    Science.gov (United States)

    Peppler, Marie C.; Fitzpatrick, Faith A.

    2018-03-09

    Stream geomorphic characteristics were monitored along a 0.8-mile reach of the Fever River in the Driftless Area of southwestern Wisconsin from 2004 to 2011 where cattle grazed in paddocks along the riverbank at the University of Wisconsin-Platteville’s Pioneer Farm. The study reach encompassed seven paddocks that covered a total of 30 acres on both sides of the river. Monitoring data included channel crosssection surveys, eroding bank measurements and photograph points, erosion-pin measurements, longitudinal profile surveys, measurements of the volume of soft sediment in the channel, and repeated time-lapse photographs. Characteristics were summarized into subreaches by use of a geographic information system. From 2004 to 2007, baseline monitoring was done to identify geomorphic conditions prior to evaluating the effects of management alternatives for riparian grazing. Subsequent to the full-scale baseline monitoring, additional data were collected from 2007 to 2011. Samples of eroding bank and in-channel soft sediment were collected and analyzed for dry bulk density in 2008 for use in a sediment budget. One of the pastures was excluded from cattle grazing in the fall of 2007; in 2009 channel cross sections, longitudinal profiles, erosion-pin measurements, photographs, and a soft sediment survey were again collected along the full 0.8-mile reach for a comparison to baseline monitoring data. Channel cross sections were surveyed a final time in 2011. Lessons learned from bank monitoring with erosion pins were most numerous and included the need for consistent tracking of each pin and whether there was deposition or erosion, timing of measurements and bank conditions during measurements (frozen, postflood), and awareness of pins loosening in place. Repeated freezing and thawing of banks and consequential mass wasting and jointing enhance fluvial erosion. Monitoring equipment in the paddocks was kept flush to the ground or located high on posts to avoid injuring the

  11. Water Accounting Plus (WA+) - a water accounting procedure for complex river basins based on satellite measurements

    Science.gov (United States)

    Karimi, P.; Bastiaanssen, W. G. M.; Molden, D.

    2012-11-01

    Coping with the issue of water scarcity and growing competition for water among different sectors requires proper water management strategies and decision processes. A pre-requisite is a clear understanding of the basin hydrological processes, manageable and unmanageable water flows, the interaction with land use and opportunities to mitigate the negative effects and increase the benefits of water depletion on society. Currently, water professionals do not have a common framework that links hydrological flows to user groups of water and their benefits. The absence of a standard hydrological and water management summary is causing confusion and wrong decisions. The non-availability of water flow data is one of the underpinning reasons for not having operational water accounting systems for river basins in place. In this paper we introduce Water Accounting Plus (WA+), which is a new framework designed to provide explicit spatial information on water depletion and net withdrawal processes in complex river basins. The influence of land use on the water cycle is described explicitly by defining land use groups with common characteristics. Analogous to financial accounting, WA+ presents four sheets including (i) a resource base sheet, (ii) a consumption sheet, (iii) a productivity sheet, and (iv) a withdrawal sheet. Every sheet encompasses a set of indicators that summarize the overall water resources situation. The impact of external (e.g. climate change) and internal influences (e.g. infrastructure building) can be estimated by studying the changes in these WA+ indicators. Satellite measurements can be used for 3 out of the 4 sheets, but is not a precondition for implementing WA+ framework. Data from hydrological models and water allocation models can also be used as inputs to WA+.

  12. Geomorphology of the Southern Gulf of California Seafloor

    Science.gov (United States)

    Eakins, B. W.; Lonsdale, P. F.; Fletcher, J. M.; Ledesma, J. V.

    2004-12-01

    A Spring 2004 multibeam sonar survey defined the seafloor geomorphology of the southern part of Gulf of California and the intersection of the East Pacific Rise with the North American continent. Survey goals included mapping structural patterns formed during the rifting that opened the Gulf and identifying the spatial transition from continental rifting to seafloor spreading. Multibeam sonar imagery, augmented with archival data and a subaerial DEM of Mexico, illuminates the principal features of this boundary zone between obliquely diverging plates: (i) active and inactive oceanic risecrests within young oceanic basins that are rich in evidence for off-axis magmatic eruption and intrusion; (ii) transforms with pull-apart basins and transpressive ridges along shearing continental margins and within oceanic crust; (iii) orphaned blocks of continental crust detached from sheared and rifted continental margins; and (iv) young, still-extending continental margins dissected by submarine canyons that in many cases are deeply drowned river valleys. Many of the canyons are conduits for turbidity currents that feed deep-sea fans on oceanic and subsided continental crust, and channel sediment to spreading axes, thereby modifying the crustal accretion process. We present a series of detailed bathymetric and seafloor reflectivity maps of this MARGINS Rupturing Continental Lithosphere focus site illustrating geomorphologic features of the southern part of the Gulf, from Guaymas Basin to the Maria Magdalena Rise.

  13. Groundwater controls on river channel pattern

    Science.gov (United States)

    Bätz, Nico; Colombini, Pauline; Cherubini, Paolo; Lane, Stuart N.

    2017-04-01

    Braided rivers are characterized by high rates of morphological change. However, despite the potential for frequent disturbance, vegetated patches may develop within this system and influence long-term channel dynamics and channel patterns through the "engineering effects" of vegetation. The stabilizing effect of developing vegetation on morphological change has been widely shown by flume experiments and (historic) aerial pictures analysis. Thus, there is a balance between disturbance and stabilization, mediated through vegetation, that may determine the long-term geomorphic and biogeomorphic evolution of the river. It follows that with a change in disturbance frequency relative to the rate of vegetation establishment, a systematic geomorphological shift could occur. Research has addressed how changes in disturbance frequency affect river channel pattern, but has rarely addressed the way in which the stabilizing effects of biogeomorphic succession interact with disturbance frequency to maintain a river in a more dynamic or a less dynamic state. Here, we quantify how the interplay between groundwater access, disturbance frequency and vegetation succession, drive changes in channel pattern. We studied this complex interplay on a transitional gravel-bed river system (braided, wandering, meandering) close to Geneva (Switzerland) - the Allondon River. Dendroecological analysis demonstrate that vegetation growth is driven by groundwater access. Groundwater access conditions the rate of vegetation stabilization at the sub-reach scale and, due to a reduction in flood-related disturbance frequency over the last 50 years, drives a change in channel pattern. Where groundwater is shallower, vegetation encroachment rates were high and as flood-related disturbance decreased, the river has shifted towards a meandering state. Where groundwater was deeper, vegetation growth was limited by water-access and thus vegetation encroachment rates were low. Even though there was a

  14. Impact of value-driven scenarios on the geomorphology and ecology of lower Rhine floodplains under a changing climate

    NARCIS (Netherlands)

    Straatsma, M.W.; Schipper, A.; Perk, M. van der; Brink, N.G. van den; Leuven, R.S.E.W.; Middelkoop, H.

    2011-01-01

    In the future, the bio-geomorphological functioning of lowland floodplains is likely to be altered at an increasing pace. Together with increasing socio-economic demands, climatic changes are expected to increase the pressures on lowland rivers in developed countries. To cope with

  15. The geomorphology of the wet and dry tropics and problems associated with the storage of uranium tailings in Northern Australia

    International Nuclear Information System (INIS)

    Warner, R.F.; Pickup, G.

    1982-01-01

    This paper describes the principal landforms of the Alligator Rivers Region Uranium Province of Northern Australia, reviews work on landforms and processes in this wet and dry tropical environment, and discusses the kinds of geomorphological hazards which might be encountered in disposing of uranium tailings at the Nabarlek, Ranger, Koongarra and Jabiluka Uranium Project Sites

  16. A geomorphology-based ANFIS model for multi-station modeling of rainfall-runoff process

    Science.gov (United States)

    Nourani, Vahid; Komasi, Mehdi

    2013-05-01

    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.

  17. Radiocarbon ages of upper quaternary deposit in central Nepal and their geomorphological significance

    International Nuclear Information System (INIS)

    Yamanaka, Hidetsugu

    1982-01-01

    The author visited Nepal from October, 1980, to February, 1981, investigated the geomorphology and upper Quaternary geology in Central Nepal, and collected a number of samples for radiocarbon dating. After returning to his university, he dated ten samples by himself. In Nepal, radiocarbon age has been scarcely reported as yet, besides in Kathmandu valley. Therefore, the author's ten data of the age are very important for the late Quaternary chronological study of Nepal Himalayas. In this paper, the author describes sampling localities and horizons, dating results and their geomorphological significance. These ten samples included Pokhara valley, Marsyandi Kohla, Modi Khola, Madi Khola and Muktinath samples. Some conclusion was derived as for the geomorphological development in central Nepal: The last Himalayan glacial age had already ended before 9,000 yr BP (years before A.D. 1950); In the Midland region, from 4,300 to 600 yr BP, some large-scale mudflows broke out nearly contemporaneously in the upper valleys, and they flowed down torrentially and catastrophically to deposit in the middle course of rivers. But the cause of vast quantity of material suddenly brought down from the Great Himalayas has been still left unexplained. The conclusion like this also was able to be applied to the middle Marsyandi Khola and the Pokhara valley. The wide-spread schema that the river was aggraded in the glacial age and degraded in the interglacial age may not be applicable to the rivers in the Midland region of Nepal Himalayas. (Wakatsuki, Y.)

  18. Geomorphology and the uranium vein deposits of the Beira region of Portugal

    International Nuclear Information System (INIS)

    Cameron, J.

    1982-01-01

    Geomorphology, river drainage patterns and land form may be related to and indicative of, the presence of metalliferous vein structures, particularly if these are composed of either harder or softer gangue material than the enclosing host rock, and where the structures are relatively recent or uncomplicated by later tectonic movements. The Beira region of Portugal is an excellent example of the relationship between uranium-bearing vein and fault structures and the local geomorphology. The Serra da Estrela mountain range dominates the region and is a horst block whose long axis trends N48 0 E and is bounded by well-defined fracture systems N60 0 E on the north-west side and N35 0 E on the south-east side. The uranium veins, the main river courses and the diabase dyke structures to the north-west and south-east of the mountains are parallel to these two bounding fault systems. The close relationship between the uranium vein structures and the geomorphology, particularly the river courses, must indicate that the veins are young in age and closely related to, but immediately following, the uplift of the Serra da Estrela mountains. The uplift of the Serra da Estrela mountains is caused by the effects of the Alpine movements on the Iberian Peninsula and dated at a probable mid- to late Oligocene age. The uranium vein structures must therefore be close to and immediately following that age. (author)

  19. Joint optimization scheduling for water conservancy projects in complex river networks

    Directory of Open Access Journals (Sweden)

    Qin Liu

    2017-01-01

    Full Text Available In this study, we simulated water flow in a water conservancy project consisting of various hydraulic structures, such as sluices, pumping stations, hydropower stations, ship locks, and culverts, and developed a multi-period and multi-variable joint optimization scheduling model for flood control, drainage, and irrigation. In this model, the number of sluice holes, pump units, and hydropower station units to be opened were used as decision variables, and different optimization objectives and constraints were considered. This model was solved with improved genetic algorithms and verified using the Huaian Water Conservancy Project as an example. The results show that the use of the joint optimization scheduling led to a 10% increase in the power generation capacity and a 15% reduction in the total energy consumption. The change in the water level was reduced by 0.25 m upstream of the Yundong Sluice, and by 50% downstream of pumping stations No. 1, No. 2, and No. 4. It is clear that the joint optimization scheduling proposed in this study can effectively improve power generation capacity of the project, minimize operating costs and energy consumption, and enable more stable operation of various hydraulic structures. The results may provide references for the management of water conservancy projects in complex river networks.

  20. Occupancy modeling and estimation of the holiday darter species complex within the Etowah River system

    Science.gov (United States)

    Anderson, Gregory B.; Freeman, Mary C.; Hagler, Megan M.; Freeman, Byron J.

    2012-01-01

    Documenting the status of rare fishes is a crucial step in effectively managing populations and implementing regulatory mechanisms of protection. In recent years, site occupancy has become an increasingly popular metric for assessing populations, but species distribution models that do not account for imperfect detection can underestimate the proportion of sites occupied and the strength of the relationship with a hypothesized covariate. However, valid detection requires temporal or spatial replication, which is often not feasible due to logistical or budget constraints. In this study, we used a method that allowed for spatial replication during a single visit to evaluate the current status of the holiday darter species complex, Etheostoma sp. cf. E. brevirostrum, within the Etowah River system. Moreover, the modeling approach used in this study facilitated comparisons of factors influencing stream occupancy as well as species detection within sites. The results suggest that there is less habitat available for the Etowah holiday darter form (Etheostoma sp. cf. E. brevirostrum B) than for the Amicalola holiday darter form (Etheostoma sp. cf. E. brevirostrum A). Additionally, occupancy models suggest that even small decreases in forest cover within these headwater systems adversely affect holiday darter populations.

  1. Weak Learner Method for Estimating River Discharges using Remotely Sensed Data: Central Congo River as a Testbed

    Science.gov (United States)

    Kim, D.; Lee, H.; Yu, H.; Beighley, E.; Durand, M. T.; Alsdorf, D. E.; Hwang, E.

    2017-12-01

    River discharge is a prerequisite for an understanding of flood hazard and water resource management, yet we have poor knowledge of it, especially over remote basins. Previous studies have successfully used a classic hydraulic geometry, at-many-stations hydraulic geometry (AMHG), and Manning's equation to estimate the river discharge. Theoretical bases of these empirical methods were introduced by Leopold and Maddock (1953) and Manning (1889), and those have been long used in the field of hydrology, water resources, and geomorphology. However, the methods to estimate the river discharge from remotely sensed data essentially require bathymetric information of the river or are not applicable to braided rivers. Furthermore, the methods used in the previous studies adopted assumptions of river conditions to be steady and uniform. Consequently, those methods have limitations in estimating the river discharge in complex and unsteady flow in nature. In this study, we developed a novel approach to estimating river discharges by applying the weak learner method (here termed WLQ), which is one of the ensemble methods using multiple classifiers, to the remotely sensed measurements of water levels from Envisat altimetry, effective river widths from PALSAR images, and multi-temporal surface water slopes over a part of the mainstem Congo. Compared with the methods used in the previous studies, the root mean square error (RMSE) decreased from 5,089 m3s-1 to 3,701 m3s-1, and the relative RMSE (RRMSE) improved from 12% to 8%. It is expected that our method can provide improved estimates of river discharges in complex and unsteady flow conditions based on the data-driven prediction model by machine learning (i.e. WLQ), even when the bathymetric data is not available or in case of the braided rivers. Moreover, it is also expected that the WLQ can be applied to the measurements of river levels, slopes and widths from the future Surface Water Ocean Topography (SWOT) mission to be

  2. Parameterization of a complex landscape for a sediment routing model of the Le Sueur River, southern Minnesota

    Science.gov (United States)

    Belmont, P.; Viparelli, E.; Parker, G.; Lauer, W.; Jennings, C.; Gran, K.; Wilcock, P.; Melesse, A.

    2008-12-01

    Modeling sediment fluxes and pathways in complex landscapes is limited by our inability to accurately measure and integrate heterogeneous, spatially distributed sources into a single coherent, predictive geomorphic transport law. In this study, we partition the complex landscape of the Le Sueur River watershed into five distributed primary source types, bluffs (including strath terrace caps), ravines, streambanks, tributaries, and flat,agriculture-dominated uplands. The sediment contribution of each source is quantified independently and parameterized for use in a sand and mud routing model. Rigorous modeling of the evolution of this landscape and sediment flux from each source type requires consideration of substrate characteristics, heterogeneity, and spatial connectivity. The subsurface architecture of the Le Sueur drainage basin is defined by a layer cake sequence of fine-grained tills, interbedded with fluvioglacial sands. Nearly instantaneous baselevel fall of 65 m occurred at 11.5 ka, as a result of the catastrophic draining of glacial Lake Agassiz through the Minnesota River, to which the Le Sueur is a tributary. The major knickpoint that was generated from that event has propagated 40 km into the Le Sueur network, initiating an incised river valley with tall, retreating bluffs and actively incising ravines. Loading estimates constrained by river gaging records that bound the knick zone indicate that bluffs connected to the river are retreating at an average rate of less than 2 cm per year and ravines are incising at an average rate of less than 0.8 mm per year, consistent with the Holocene average incision rate on the main stem of the river of less than 0.6 mm per year. Ongoing work with cosmogenic nuclide sediment tracers, ground-based LiDAR, historic aerial photos, and field mapping will be combined to represent the diversity of erosional environments and processes in a single coherent routing model.

  3. GEOMORPHOLOGICAL HAZARDS AND RISKS IN JIU DEFILE

    Directory of Open Access Journals (Sweden)

    I. SĂNDULACHE

    2014-05-01

    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.

  4. Geomorphology subprogram: Geomorphological map of Occidental region of Bolivia, utilizing ERTS imagery

    Science.gov (United States)

    Brockmann, C. E. (Principal Investigator); Suarez, M. M.

    1973-01-01

    The author has identified the following significant results. Due to the receipt of ERTS-1 imagery, Bolivia will have for the first time a geomorphological map at a scale of 1:100,000. Now the researcher and the student will be able to compare the distribution of the existing shapes of the country, which have been modelled by diverse processes, factors, and agents. This geomorphological information will be very useful in its application to mining, especially alluvial beds, engineering work, and other geological studies. This map is divided into ten geomorphological units which coincide with the geostructural units of the western region of the country.

  5. Effectiveness evaluation of flood defence structures in different geomorphological contexts

    Science.gov (United States)

    Morelli, Stefano; Pazzi, Veronica; Fanti, Riccardo

    2017-04-01

    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

  6. Evaluating greenhouse gas emissions from hydropower complexes on large rivers in Eastern Washington

    Energy Technology Data Exchange (ETDEWEB)

    Arntzen, Evan V.; Miller, Benjamin L.; O' Toole, Amanda C.; Niehus, Sara E.; Richmond, Marshall C.

    2013-03-15

    Water bodies, such as freshwater lakes, are known to be net emitters of carbon dioxide (CO2), and methane (CH4). In recent years, significant greenhouse gas (GHG) emissions from tropical, boreal, and mid-latitude reservoirs have been reported. At a time when hydropower is increasing worldwide, better understanding of seasonal and regional variation in GHG emissions is needed in order to develop a predictive understanding of such fluxes within man-made impoundments. We examined power-producing dam complexes within xeric temperate locations in the northwestern United States. Sampling environments on the Snake (Lower Monumental Dam Complex) and Columbia Rivers (Priest Rapids Dam Complex) included tributary, mainstem, embayment, forebay, and tailrace areas during winter and summer 2012. At each sampling location, GHG measurement pathways included surface gas flux, degassing as water passed through dams during power generation, ebullition within littoral embayments, and direct sampling of hyporheic pore-water. Measurements were also carried out in a free-flowing reach of the Columbia River to estimate unaltered conditions. Surface flux resulted in very low emissions, with reservoirs acting as a sink for CO2 (up to –262 mg m-2 d-1, which is within the range previously reported for similarly located reservoirs). Surface flux of methane remained below 1 mg CH4 m-2d-1, a value well below fluxes reported previously for temperate reservoirs. Water passing through hydroelectric projects acted as a sink for CO2 during winter and a small source during summer, with mean degassing fluxes of –117 and 4.5 t CO2 d-1, respectively. Degassing of CH4 was minimal, with mean fluxes of 3.1 × 10-6 and –5.6 × 10-4 t CH4 d-1 during winter and summer, respectively. Gas flux due to ebullition was greater in coves located within reservoirs than in coves within the free flowing Hanford Reach–and CH4 flux exceeded that of CO2. Methane emissions varied widely across sampling locations

  7. Spatiotemporal Co-existence of Two Mycobacterium ulcerans Clonal Complexes in the Offin River Valley of Ghana.

    Directory of Open Access Journals (Sweden)

    Araceli Lamelas

    2016-07-01

    Full Text Available In recent years, comparative genome sequence analysis of African Mycobacterium ulcerans strains isolated from Buruli ulcer (BU lesion specimen has revealed a very limited genetic diversity of closely related isolates and a striking association between genotype and geographical origin of the patients. Here, we compared whole genome sequences of five M. ulcerans strains isolated in 2004 or 2013 from BU lesions of four residents of the Offin river valley with 48 strains isolated between 2002 and 2005 from BU lesions of individuals residing in the Densu river valley of Ghana. While all M. ulcerans isolates from the Densu river valley belonged to the same clonal complex, members of two distinct clonal complexes were found in the Offin river valley over space and time. The Offin strains were closely related to genotypes from either the Densu region or from the Asante Akim North district of Ghana. These results point towards an occasional involvement of a mobile reservoir in the transmission of M. ulcerans, enabling the spread of bacteria across different regions.

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

    Directory of Open Access Journals (Sweden)

    Bahram Saeidifarzad

    2014-09-01

    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.

  9. Habitat hydrology and geomorphology control the distribution of malaria vector larvae in rural Africa.

    Science.gov (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

    2013-01-01

    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.

  10. Tropical Peatland Geomorphology and Hydrology

    Science.gov (United States)

    Cobb, A.; Harvey, C. F.

    2017-12-01

    Tropical peatlands cover many low-lying areas in the tropics. In tropical peatlands, a feedback between hydrology, landscape morphology, and carbon storage causes waterlogged organic matter to accumulate into gently mounded land forms called peat domes over thousands of years. Peat domes have a stable morphology in which peat production is balanced by loss and net precipitation is balanced by lateral flow, creating a link between peatland morphology, rainfall patterns and drainage networks. We show how landscape morphology can be used to make inferences about hydrologic processes in tropical peatlands. In particular, we show that approaches using simple storage-discharge relationships for catchments are especially well suited to tropical peatlands, allowing river forecasting based on peatland morphology in catchments with tropical peatland subcatchments.

  11. Geomorphologic, stratigraphic and sedimentologic evidences of ...

    Indian Academy of Sciences (India)

    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 ...

  12. Geomorphological hazards in Swat valley, Pakistan

    International Nuclear Information System (INIS)

    Usman, A.

    1999-01-01

    This study attempts to describe, interpret and analyze, in depth, the varied geomorphological hazards and their impacts prevailing in the swat valley locate in the northern hilly and mountainous regions of Pakistan. The hills and mountains re zones of high geomorphological activity with rapid rates of weathering, active tectonic activities, abundant precipitation, rapid runoff and heavy sediment transport. Due to the varied topography, lithology, steep slope, erodible soil, heavy winter snowfall and intensive rainfall in the spring and summer seasons, several kinds of geomorphological hazards, such as geomorphic gravitational hazards, Fluvial hazards, Glacial hazards, Geo tectonic hazards, are occurring frequently in swat valley. Amongst them, geomorphic gravitational hazards, such as rock fall rock slide, debris slide mud flow avalanches, are major hazards in mountains and hills while fluvial hazards and sedimentation are mainly confined to the alluvial plain and lowlands of the valley. The Getechtonic hazards, on the other hand, have wide spread distribution in the valley the magnitude and occurrence of each king of hazard is thus, varied according to intensity of process and physical geographic environment. This paper discusses the type distribution and damage due to the various geomorphological hazards and their reduction treatments. The study would to be of particular importance and interest to both natural and social scientists, as well as planner, environmentalists and decision-makers for successful developmental interventions in the region. (author)

  13. Incorporating Concept Sketching into Teaching Undergraduate Geomorphology

    Science.gov (United States)

    Reusser, Lucas J.; Corbett, Lee B.; Bierman, Paul R.

    2012-01-01

    Constructing concept sketches (diagrams annotated with short captions in which students demonstrate their understanding of form, process, and interactions) provides a new and different way to teach Earth surface processes and assess the depth of student learning. During a semester-long course in Geomorphology, we used concept sketches as an…

  14. COMPLEX NETWORK SIMULATION OF FOREST NETWORK SPATIAL PATTERN IN PEARL RIVER DELTA

    Directory of Open Access Journals (Sweden)

    Y. Zeng

    2017-09-01

    Full Text Available Forest network-construction uses for the method and model with the scale-free features of complex network theory based on random graph theory and dynamic network nodes which show a power-law distribution phenomenon. The model is suitable for ecological disturbance by larger ecological landscape Pearl River Delta consistent recovery. Remote sensing and GIS spatial data are available through the latest forest patches. A standard scale-free network node distribution model calculates the area of forest network’s power-law distribution parameter value size; The recent existing forest polygons which are defined as nodes can compute the network nodes decaying index value of the network’s degree distribution. The parameters of forest network are picked up then make a spatial transition to GIS real world models. Hence the connection is automatically generated by minimizing the ecological corridor by the least cost rule between the near nodes. Based on scale-free network node distribution requirements, select the number compared with less, a huge point of aggregation as a future forest planning network’s main node, and put them with the existing node sequence comparison. By this theory, the forest ecological projects in the past avoid being fragmented, scattered disorderly phenomena. The previous regular forest networks can be reduced the required forest planting costs by this method. For ecological restoration of tropical and subtropical in south China areas, it will provide an effective method for the forest entering city project guidance and demonstration with other ecological networks (water, climate network, etc. for networking a standard and base datum.

  15. A Model of Beaver Meadow Complex Evolution in the Silvies River Basin, Oregon.

    Science.gov (United States)

    Nash, C.; Grant, G.; Campbell, S. D.

    2014-12-01

    There is increasing evidence to suggest that the pervasive incision seen in the American West is due, in part, to the removal of beaver (Castor canadensis) in the first half of the 19th century. New restoration strategies for these systems focus on the reintroduction of beaver and construction of beaver dam analogs. Such dams locally raise streams beds and water tables, reconnect incised channels to their former floodplains, trap sediment, increase hydraulic diversity, and promote riparian vegetation. However, the geomorphic and hydrologic impacts of both the original beaver dams and their analogs are poorly understood. Observations in the Silvies River basin in Oregon, USA - an upland, semi-arid catchment with extremely high historic beaver populations and a presently recovering population, inform a conceptual model for valley floor evolution with beaver dams. The evolution of the beaver dam complex is characterized by eight stages of morphologic adjustment: water impoundment, sediment deposition, pond filling, multi-thread meadow creation, dam breaching, channel incision, channel widening, and floodplain development. Well-constructed beaver dams, given sufficient time and sediment flux, will evolve from a series of ponds to a multi-threaded channel flowing through a wet meadow complex. If a dam in the system fails, due to overtopping, undercutting, lack of maintenance, or abandonment, the upstream channel will concentrate into a single channel and incise, followed over time by widening once critical bank heights are exceeded. From stratigraphic, dendrochronologic, and geomorphic measurements, we are constraining average timescales associated with each stage's duration and transitional period. Measured sedimentation rates behind modern beaver dam analogs on five stream systems permit calculation of sediment flux over recent time periods, and aid in developing regional rates of sediment deposition over a range of drainage areas and gradients. Stratigraphic and

  16. Quantifying hyporheic exchange dynamics in a highly regulated large river reach.

    Energy Technology Data Exchange (ETDEWEB)

    Hammond, Glenn Edward; Zhou, T; Huang, M; Hou, Z; Bao, J; Arntzen, E; Mackley, R; Harding, S; Titzler, S; Murray, C; Perkins, W; Chen, X; Stegen, J; Thorne, P; Zachara, J

    2017-03-01

    Hyporheic exchange is an important mechanism taking place in riverbanks and riverbed sediments, where river water and shallow groundwater mix and interact with each other. The direction, magnitude, and residence time of the hyporheic flux that penetrates the river bed are critical for biogeochemical processes such as carbon and nitrogen cycling, and biodegradation of organic contaminants. Many approaches including field measurements and numerical methods have been developed to quantify the hyporheic exchanges in relatively small rivers. However, the spatial and temporal distributions of hyporheic exchanges in a large, regulated river reach remain less explored due to the large spatial domains, complexity of geomorphologic features and subsurface properties, and the great pressure gradient variations at the riverbed created by dam operations.

  17. 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

    2016-01-01

    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.

  18. Effects of alluvial knickpoint migration on floodplain ecology and geomorphology

    Science.gov (United States)

    Larsen, Annegret; May, Jan-Hendrick

    2016-04-01

    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.

  19. Mapping Drought Sensitivity of Ecosystem Functioning in Mountainous Watersheds: Spatial Heterogeneity and Geological-Geomorphological Control

    Science.gov (United States)

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

    2016-12-01

    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

  20. Noise is the new signal: Moving beyond zeroth-order geomorphology (Invited)

    Science.gov (United States)

    Jerolmack, D. J.

    2010-12-01

    The last several decades have witnessed a rapid growth in our understanding of landscape evolution, led by the development of geomorphic transport laws - time- and space-averaged equations relating mass flux to some physical process(es). In statistical mechanics this approach is called mean field theory (MFT), in which complex many-body interactions are replaced with an external field that represents the average effect of those interactions. Because MFT neglects all fluctuations around the mean, it has been described as a zeroth-order fluctuation model. The mean field approach to geomorphology has enabled the development of landscape evolution models, and led to a fundamental understanding of many landform patterns. Recent research, however, has highlighted two limitations of MFT: (1) The integral (averaging) time and space scales in geomorphic systems are sometimes poorly defined and often quite large, placing the mean field approximation on uncertain footing, and; (2) In systems exhibiting fractal behavior, an integral scale does not exist - e.g., properties like mass flux are scale-dependent. In both cases, fluctuations in sediment transport are non-negligible over the scales of interest. In this talk I will synthesize recent experimental and theoretical work that confronts these limitations. Discrete element models of fluid and grain interactions show promise for elucidating transport mechanics and pattern-forming instabilities, but require detailed knowledge of micro-scale processes and are computationally expensive. An alternative approach is to begin with a reasonable MFT, and then add higher-order terms that capture the statistical dynamics of fluctuations. In either case, moving beyond zeroth-order geomorphology requires a careful examination of the origins and structure of transport “noise”. I will attempt to show how studying the signal in noise can both reveal interesting new physics, and also help to formalize the applicability of geomorphic

  1. Spatial and temporal variation of heavy metals in sediment cores from the Calcasieu River/Lake Complex

    International Nuclear Information System (INIS)

    Mueller, C.S.; Ramelow, G.J.; Beck, J.N.

    1987-01-01

    Sediment cores were obtained from several locations in the Calcasieu River/Lake Complex, including Calcasieu Lake, Calcasieu River, two bayou tributaries, and Lake Charles during the period from November 1983 to November 1985. The cores were analyzed for Cu, Zn, Cr, and Pb. The approximate sedimentation rate and a core chronology were determined by the use of 137 Cs and 210 Pb isotopes. The increase in metal concentrations after 1933, particularly along Bayou d'Inde where most industries are located, points to anthropogenic input if these metals to the system. The fact that metal concentrations tend to merge to a common value prior to 1940 throughout the system suggests that geological factors do not contribute to the observed variations in metal concentrations in this area. The background concentrations of heavy metals found in this study for the Calcasieu River/Lake Complex were: Cu (10 mg kg -1 ), Cr (25 mg kg -1 ), Pb (8 mg kg -1 ), and Zn (40 mg kg -1 ). The main emphasis of the study focused along Bayou d'Inde due to the enhanced levels of heavy metals found

  2. Application for 3d Scene Understanding in Detecting Discharge of Domesticwaste Along Complex Urban Rivers

    Science.gov (United States)

    Ninsalam, Y.; Qin, R.; Rekittke, J.

    2016-06-01

    In our study we use 3D scene understanding to detect the discharge of domestic solid waste along an urban river. Solid waste found along the Ciliwung River in the neighbourhoods of Bukit Duri and Kampung Melayu may be attributed to households. This is in part due to inadequate municipal waste infrastructure and services which has caused those living along the river to rely upon it for waste disposal. However, there has been little research to understand the prevalence of household waste along the river. Our aim is to develop a methodology that deploys a low cost sensor to identify point source discharge of solid waste using image classification methods. To demonstrate this we describe the following five-step method: 1) a strip of GoPro images are captured photogrammetrically and processed for dense point cloud generation; 2) depth for each image is generated through a backward projection of the point clouds; 3) a supervised image classification method based on Random Forest classifier is applied on the view dependent red, green, blue and depth (RGB-D) data; 4) point discharge locations of solid waste can then be mapped by projecting the classified images to the 3D point clouds; 5) then the landscape elements are classified into five types, such as vegetation, human settlement, soil, water and solid waste. While this work is still ongoing, the initial results have demonstrated that it is possible to perform quantitative studies that may help reveal and estimate the amount of waste present along the river bank.

  3. Geomorphological investigations and GIS approach of the Tamiš loess plateau, Banat region (northern Serbia

    Directory of Open Access Journals (Sweden)

    Popov Dragan

    2012-01-01

    Full Text Available The focus of this study was the loess plateau located in the Tamiš River valley in the central part of Banat region (northern Serbia. This morphologic unit has been formed by the loess accumulation process during the last two glacial periods. Digital elevation model (DEM is based on the 1:25.000 scale topographic maps. Detailed geomorphologic and hypsometric maps are provided with selected cross sections. The borders of the plateau and spatial distribution of the micromorphology are precisely defined on DEM. The plateau rises gradually from the Upper Pleistocene terrace on the north and northwest, while to the east and south slopes and vertical bluffs were controlled by the lateral erosion process of surrounding channels and by the weathering process on the loess. The plateau has an atypical morphology characterized by reduced geomorphologic diversity. Loess topography is significantly flattened by human impact. Its micromorphology is characterised by shallow depressions and gullies.

  4. Geomorphology of coastal environments from satellite images

    International Nuclear Information System (INIS)

    Da Rocha Ribeiro, R.; Velho, L.; Schossler, V.

    2010-01-01

    This study aims at recognizing coastal environments supported by data from the Landsat Thematic Mapper (TM) satellite. The digital processing of images, System Information Geographic (SIG) techniques and field observation in one section of the “Província Costeira do Rio Grande do Sul” between the Rio Grande and the São Gonçalo channels - resulted in a geomorphologic profile and mapping

  5. Boulders, biology and buildings: Why weathering is vital to geomorphology (Ralph Alger Bagnold Medal Lecture)

    Science.gov (United States)

    Viles, Heather A.

    2015-04-01

    Weathering is vital to geomorphology in three main senses. First, it is vital in the sense of being a fundamental and near-ubiquitous earth surface process without which landscapes would not develop, and which also provides a key link between geomorphology and the broader Earth system. Second, weathering is vital in the sense that, as it is heavily influenced by biotic processes, it demonstrates the importance of life to geomorphology and vice versa. In particular, weathering illustrates the many cross-linkages between microbial ecosystems and geomorphology. Finally, it is vital in the sense that weathering provides an important practical application of geomorphological knowledge. Geomorphologists in recent years have contributed much in terms of improving understanding the deterioration of rocks, stone and other materials in heritage sites and the built environment. This knowledge has also had direct implications for heritage conservation. This lecture reviews recent research on each of these three themes and on their linkages, and sets an integrated research agenda for the future. Weathering as a key process underpinning geomorphology and Earth system science has been the subject of much recent conceptual and empirical research. In particular, conceptual research advances have involved improving conceptualisation of scale issues and process synergies, and understanding weathering in terms of non-linear dynamical systems. Empirical advances have included the development of larger datasets on weathering rates, and the application of a wide range of non-destructive and remote sensing techniques to quantify weathering morphologies on boulder and rock surfaces. In recent years, understanding of the complex linkages between ecology and geomorphology (sometimes called biogeomorphology) has advanced particularly strongly in terms of weathering. For example, the influences of disturbance on biota and weathering have been conceptualised and investigated empirically in a

  6. Recent Geomorphological Evolution in the Southern Part of the Middle Russian Upland (Russia)

    Science.gov (United States)

    Romanovskaya, Maria; Sukhanova, Tatyana; Krilkov, Nikita

    2017-04-01

    The Middle Russian Upland occupies the central part of the East European Plain. Our structural and geomorphological study of the Upland's southern segment (mostly of the Ostrogozhsk Uplift) exposed the presence of differently aged erosion-shaped denudational, erosion-shaped accumulational and purely accumulational surfaces, each with its own complex of recent deposits. The entire landscape is a system of altitudinal 'steps', or 'levels', which we believe were formed by uneven neotectonic movements and also influenced by climate fluctuations. The highest (220 - 230 m above sea level) and the oldest day light surface of the Ostrogozhsk Uplift lies on Poltava- and Shapkino-type deposit suites and dates from the Late Miocene. A surface at about 200 m dates from the Late Miocene and the Pliocene. Surfaces at 180 m and 150 m date from the Eopleistocene and the Early Pleistocene, respectively. The former lies on Kiev-type deposits, and the latter - on fluvioglacial deposits from the time of the maximum Dnepr (or Don) Glaciations. The valleys of the rivers Don and Tikhaya Sosna have fluvial terraces above their floodplains all formed under the influence of the Don, Dnepr, Moscow and, Valdai Glaciations. Terrace IV (at about 60 m above river level) formed in the opening half of the Middle Neopleistocene. Terrace III (40 m), formed in the closing half of the Middle Neopleistocene. Terrace II (30 m), formed in the opening half of the Late Neopleistocene. Terrace II (at 10 to 12 m), formed in the closing half of the Late Neopleistocene. The floodplain (at 2 to 4 m), formed in the Holocene. There is ample evidence of neotectonic activity in the surveyed area, namely: changes in the flow direction of the rivers Don and Tikhaya Sosna, forced to bypass the growing upland forming tectonic meanders; instances of damming up, which have led to waterlogging in floodplains; increase in the density of the erosion grid; fall of the groundwater table; intensification of erosion and slope

  7. APPLICATION FOR 3D SCENE UNDERSTANDING IN DETECTING DISCHARGE OF DOMESTICWASTE ALONG COMPLEX URBAN RIVERS

    Directory of Open Access Journals (Sweden)

    Y. Ninsalam

    2016-06-01

    Full Text Available In our study we use 3D scene understanding to detect the discharge of domestic solid waste along an urban river. Solid waste found along the Ciliwung River in the neighbourhoods of Bukit Duri and Kampung Melayu may be attributed to households. This is in part due to inadequate municipal waste infrastructure and services which has caused those living along the river to rely upon it for waste disposal. However, there has been little research to understand the prevalence of household waste along the river. Our aim is to develop a methodology that deploys a low cost sensor to identify point source discharge of solid waste using image classification methods. To demonstrate this we describe the following five-step method: 1 a strip of GoPro images are captured photogrammetrically and processed for dense point cloud generation; 2 depth for each image is generated through a backward projection of the point clouds; 3 a supervised image classification method based on Random Forest classifier is applied on the view dependent red, green, blue and depth (RGB-D data; 4 point discharge locations of solid waste can then be mapped by projecting the classified images to the 3D point clouds; 5 then the landscape elements are classified into five types, such as vegetation, human settlement, soil, water and solid waste. While this work is still ongoing, the initial results have demonstrated that it is possible to perform quantitative studies that may help reveal and estimate the amount of waste present along the river bank.

  8. Geotourist itineraries along the Italian territory: examples of mapping the geoheritage in different geomorphological and historical contexts

    Science.gov (United States)

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

    2016-04-01

    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

  9. Unified Geomorphological Analysis Workflows with Benthic Terrain Modeler

    Directory of Open Access Journals (Sweden)

    Shaun Walbridge

    2018-03-01

    Full Text Available High resolution remotely sensed bathymetric data is rapidly increasing in volume, but analyzing this data requires a mastery of a complex toolchain of disparate software, including computing derived measurements of the environment. Bathymetric gradients play a fundamental role in energy transport through the seascape. Benthic Terrain Modeler (BTM uses bathymetric data to enable simple characterization of benthic biotic communities and geologic types, and produces a collection of key geomorphological variables known to affect marine ecosystems and processes. BTM has received continual improvements since its 2008 release; here we describe the tools and morphometrics BTM can produce, the research context which this enables, and we conclude with an example application using data from a protected reef in St. Croix, US Virgin Islands.

  10. Complex hydro- and sediment dynamics survey of two critical reaches on the Hungarian part of river Danube

    International Nuclear Information System (INIS)

    Baranya, Sandor; Jozsa, Janos; Goda, Laszlo; Rakoczi, Laszlo

    2008-01-01

    Detailed hydrodynamic survey of two critical river reaches has been performed from hydro- and sediment dynamics points of view, in order to explore the main features, moreover, provide calibration and verification data to related 3D flow and sediment transport modelling. Special attention has been paid to compare moving and fix boat measurement modes for estimating various flow and large-scale bed form features, resulting in recommendations e.g. on the time period needed in stationary mode operation to obtain sufficiently stabilized average velocity profiles and related parameter estimations. As to the study reaches, the first comprises a 5 km long sandy-gravel bed reach of river Danube located in Central-Hungary, presenting problems for navigation. As a conventional remedy, groyne fields have been implemented to make and maintain the reach sufficiently deep, navigable even in low flow periods. As is usually the case, these works resulted in rather complex flow characteristics and related bed topography at places. The second site is another 5 km long reach of river Danube, close to the southern border to Serbia. There the river presents navigational problems similar to the previously mentioned reach, however, having entirely sand bed conditions, abundant in a variety of dunes, especially in the shallower parts. In both study reaches ADCP measurements were done with around 2.5 Hz sampling frequency both in moving boat operation mode providing overall, though locally moderately representative picture, and in fixed boat mode at a considerable number of selected verticals with 10 minutes long measuring time.

  11. The role of geomorphology in environmental impact assessment

    Science.gov (United States)

    Cavallin, A.; Marchetti, M.; Panizza, M.; Soldati, M.

    1994-04-01

    This paper aims to define the role of Geomorphology in the assessment of the impact of human activities on the environment. Environmental impact assessment (EIA) should be carried out for specific projects, in order to evaluate their suitability for the quality of the environment. In fact, each planned activity may have an impact on various environmental components. Among these, the natural component must be examined in terms of geomorphological hazards, which may endanger a project, and of geomorphological assets (elements forming the educational and cultural heritage of the landscape), which may be damaged to various extents by human activities. The relationships between humans and environment are taken into account, with particular attention to the effects of a project on the geomorphological environment. From a geomorphological point of view, after having assessed the suitability of a certain location, mainly with respect to its morphography and morphometry, the geomorphological hazards of the area which may threaten the project (risk) must be considered; then the geomorphological assets, which may be damaged by the same project (direct impact) have to be individuated. Human activities may produce two other kinds of effect: the first refers to the consequences of the geomorphological hazards induced by a project on the project itself (direct risk) and on the surronding areas (indirect risk); the second takes into account the potential deterioration of a geomorphological asset due to hazards induced by the project (indirect impact). Examples of these different cases are presented.

  12. Assessment of geomorphological and hydrological changes produced by Pleistocene glaciations in a Patagonian basin

    Science.gov (United States)

    Scordo, Facundo; Seitz, Carina; Melo, Walter D.; Piccolo, M. Cintia; Perillo, Gerardo M. E.

    2018-04-01

    This work aims to assess how Pleistocene glaciations modeled the landscape in the upper Senguer River basin and its relationship to current watershed features (drainage surface and fluvial hydrological regime). During the Pleistocene six glacial lobes developed in the upper basin of the Senguer River localized east of the Andean range in southern Argentinean Patagonia between 43° 36' - 46° 27‧ S. To describe the topography and hydrology, map the geomorphology, and propose an evolution of the study area during the Pleistocene we employed multitemporal Landsat images, national geological sheets and a mosaic of the digital elevation model (Shuttle Radar Topography Mission) along with fieldwork. The main conclusion is that until the Middle Pleistocene, the drainage divide of the Senguer River basin was located to the west of its current limits and its rivers drained the meltwater of the glaciers during interglacial periods. However, processes of drainage inversion and drainage surface reduction occurred in the headwater of most rivers of the basin during the Late Pleistocene. Those processes were favored by a relative shorter glacial extension during LGM and the dam effect produced by the moraines of the Post GPG I and III glaciations. Thus, since the Late Pleistocene, the headwaters of several rivers in the basin have been reduced, and the moraines corresponding to the Middle Pleistocene glaciations currently divide the watersheds that drain towards the Senguer River from those that flow west towards the Pacific Ocean.

  13. Geomorphology: Perspectives on observation, history, and the field tradition

    Science.gov (United States)

    Vitek, John D.

    2013-10-01

    Other than a common interest in form and process, current geomorphologists have little in common with those who established the foundations of this science. Educated people who had an interest in Earth processes during the nineteenth century cannot be compared to the scholars who study geomorphology in the twenty-first century. Whereas Earth has undergone natural change from the beginning of time, the human record of observing and recording processes and changes in the surface Is but a recent phenomena. Observation is the only thread, however, that connects all practitioners of geomorphology through time. As people acquired knowledge related to all aspects of life, technological revolutions, such as the Iron Age, Bronze Age, agricultural revolution, the atomic age, and the digital age, shaped human existence and thought. Technology has greatly changed the power of human observation, including inward to the atomic scale and outward into the realm of space.Books and articles describe how to collect and analyze data but few references document the field experience. Each of us, however, has experienced unique circumstances during field work and we learned from various mentors how to observe. The surface of Earth on which we practice the vocation of geomorphology may not be much different from a hundred years ago but many things about how we collect data, analyze it and disseminate the results have changed. How we function in the field, including what we wear, what we eat, how we get there, and where we choose to collect data, clearly reflects the complexity of the human system on Earth and the processes and forms that arouse our interest. Computers, miniaturization of electronics, satellite communications and observation platforms in space provide access to data to aid in our quest to understand Earth surface processes. Once, people lived closer to nature in primitive shelters in contrast with life in urban environments. But as urban life continues to expand and people

  14. Quantifying the performance of automated GIS-based geomorphological approaches for riparian zone delineation using digital elevation models

    OpenAIRE

    D. Fernández; J. Barquín; M. Álvarez-Cabria; F. J. Peñas

    2012-01-01

    Riparian zone delineation is a central issue for managing rivers and adjacent areas; 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 usually only available for populated areas at risk of flooding. In this work we created several floodplain surfaces by means of two different GIS-based geomorphological appro...

  15. The utilization of ERTS-1 data for the study of the French Atlantic Littoral. [coastal water and geomorphology

    Science.gov (United States)

    Demathieu, P. G.; Verger, F. H.

    1974-01-01

    The French Atlantic Littoral (FRALIT) program uses ERTS-1 data to study coastal geomorphology and waters. ERTS-1 gives an overall picture of the phenomena for the first time due mainly to channel 4 data, but the other channels also contribute valuable complementary data on superficial waters. These studies have already resulted in accurate maps of the mud transported south-westwards from the mouth of the River Loire.

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

    Directory of Open Access Journals (Sweden)

    Francesca Bozzano

    2017-03-01

    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.

  17. Scienti fi c Approaches and Methods in the Investigation of the Formation and Stability of Hydromorphic Natural Complexes of the Irtysh River Valley System (The Kazakhstan Part

    Directory of Open Access Journals (Sweden)

    A. G. Tsaregorodtseva

    2006-12-01

    Full Text Available The current geo-environmental situation of the Irtysh River valley system is connected with the high degree of control of the river drainage, which affects the functioning of its entire ecosystem and determines some morphological features of its channel. In the present work, the methodological approaches in the study of formation of the valley’s hydromorphic natural complexes are discussed, and the results of studies on the channel processes in the middle course of the Irtysh River are given.

  18. Smart "geomorphological" map browsing - a tale about geomorphological maps and the internet

    Science.gov (United States)

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

    2012-04-01

    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

  19. Humin to Human: Organic carbon, sediment, and water fluxes along river corridors in a changing world

    Energy Technology Data Exchange (ETDEWEB)

    Sutfin, Nicholas Alan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-11-20

    This is a presentation with slides on What does it mean to be human? ...humin?; River flow and Hydrographs; Snake River altered hydrograph (Marston et al., 2005); Carbon dynamics are important in rivers; Rivers and streams as carbon sink; Reservoirs for organic carbon; Study sites in Colorado; River morphology; Soil sample collection; Surveys at RMNP; Soil organic carbon content at RMNP; Abandoned channels and Cutoffs; East River channel migration and erosion; Linking hydrology to floodplain sediment flux; Impact of Extreme Floods on Floodplain Sediment; Channel Geometry: RMNP; Beavers dams and multithread channels; Geomorphology and carbon in N. St. Vrain Creek; Geomorphology and carbon along the East River; Geomorphology and carbon in N. St. Vrain Creek; San Marcos River, etc.

  20. Geomorphology, active tectonics, and landscape evolution in the Mid-Atlantic region: Chapter

    Science.gov (United States)

    Pazzaglia, Frank J.; Carter, Mark W.; Berti, Claudio; Counts, Ronald C.; Hancock, Gregory S.; Harbor, David; Harrison, Richard W.; Heller, Matthew J.; Mahan, Shannon; Malenda, Helen; McKeon, Ryan; Nelson, Michelle S.; Prince, Phillip; Rittenour, Tammy M.; Spotilla, James; Whittecar, G. Richard

    2015-01-01

    In 2014, the geomorphology community marked the 125th birthday of one of its most influential papers, “The Rivers and Valleys of Pennsylvania” by William Morris Davis. Inspired by Davis’s work, the Appalachian landscape rapidly became fertile ground for the development and testing of several grand landscape evolution paradigms, culminating with John Hack’s dynamic equilibrium in 1960. As part of the 2015 GSA Annual Meeting, the Geomorphology, Active Tectonics, and Landscape Evolution field trip offers an excellent venue for exploring Appalachian geomorphology through the lens of the Appalachian landscape, leveraging exciting research by a new generation of process-oriented geomorphologists and geologic field mapping. Important geomorphologic scholarship has recently used the Appalachian landscape as the testing ground for ideas on long- and short-term erosion, dynamic topography, glacial-isostatic adjustments, active tectonics in an intraplate setting, river incision, periglacial processes, and soil-saprolite formation. This field trip explores a geologic and geomorphic transect of the mid-Atlantic margin, starting in the Blue Ridge of Virginia and proceeding to the east across the Piedmont to the Coastal Plain. The emphasis here will not only be on the geomorphology, but also the underlying geology that establishes the template and foundation upon which surface processes have etched out the familiar Appalachian landscape. The first day focuses on new and published work that highlights Cenozoic sedimentary deposits, soils, paleosols, and geomorphic markers (terraces and knickpoints) that are being used to reconstruct a late Cenozoic history of erosion, deposition, climate change, and active tectonics. The second day is similarly devoted to new and published work documenting the fluvial geomorphic response to active tectonics in the Central Virginia seismic zone (CVSZ), site of the 2011 M 5.8 Mineral earthquake and the integrated record of Appalachian

  1. The Teaching of Geomorphology and the Geography/Geology Debate.

    Science.gov (United States)

    Petch, Jim; Reid, Ian

    1988-01-01

    Examines the place of geomorphology in undergraduate programs in the United Kingdom. A questionnaire survey reveals that geomorphology is widely taught in all geo- and environmental sciences, but that teaching methods and the size of the curriculum vary significantly between disciplines. (LS)

  2. Geomorphological investigation of multiphase glacitectonic composite ridge systems in Svalbard

    Science.gov (United States)

    Lovell, Harold; Benn, Douglas I.; Lukas, Sven; Spagnolo, Matteo; Cook, Simon J.; Swift, Darrel A.; Clark, Chris D.; Yde, Jacob C.; Watts, Tom

    2018-01-01

    Some surge-type glaciers on the High-Arctic archipelago of Svalbard have large glacitectonic composite ridge systems at their terrestrial margins. These have formed by rapid glacier advance into proglacial sediments during the active surge phase, creating multicrested moraine complexes. Such complexes can be formed during single surge advances or multiple surges to successively less-extensive positions. The few existing studies of composite ridge systems have largely relied on detailed information on internal structure and sedimentology to reconstruct their formation and links to surge processes. However, natural exposures of internal structure are commonly unavailable, and the creation of artificial exposures is often problematic in fragile Arctic environments. To compensate for these issues, we investigate the potential for reconstructing composite ridge system formation based on geomorphological evidence alone, focusing on clear morphostratigraphic relationships between ridges within the moraine complex and relict meltwater channels/outwash fans. Based on mapping at the margins of Finsterwalderbreen (in Van Keulenfjorden) and Grønfjordbreen (in Grønfjorden), we show that relict meltwater channels that breach outer parts of the composite ridge systems are in most cases truncated upstream within the ridge complex by an inner pushed ridge or ridges at their ice-proximal extents. Our interpretation of this relationship is that the entire composite ridge system is unlikely to have formed during the same glacier advance but is instead the product of multiple advances to successively less-extensive positions, whereby younger ridges are emplaced on the ice-proximal side of older ridges. This indicates that the Finsterwalderbreen composite ridge system has been formed by multiple separate advances, consistent with the cyclicity of surges. Being able to identify the frequency and magnitude of former surges is important as it provides insight into the past behaviour of

  3. Intensity of geomorphological processes in NW sector of Pacific rim marginal mountain belts

    Science.gov (United States)

    Lebedeva, Ekaterina; Shvarev, Sergey; Gotvansky, Veniamin

    2014-05-01

    Continental marginal mountains, including the mountain belts of Russian Far East, are characterized by supreme terrain contrast, mosaic structure of surface and crust, and rich complex of modern endogenous processes - volcanism, seismicity, and vertical movements. Unstable state of geomorphological systems and activity of relief forming processes here is caused also by deep dissected topography and the type and amount of precipitation. Human activities further stimulate natural processes and increase the risk of local disasters. So these territories have high intensity (or tension) of geomorphological processes. Intensity in the authors' understanding is willingness of geomorphological system to be out of balance, risk of disaster under external and internal agent, both natural and human. Mapping with quantitative accounting of intensity of natural and human potential impact is necessary for indication the areal distribution trends of geomorphological processes intensity and zones of potential risk of disasters. Methods of map drowning up are based on several criteria analyzing: 1) total terrain-form processes and their willingness to be a hazard-like, 2) existence, peculiarity and zoning of external agents which could cause extreme character of base processes within the territory, 3) peculiarity of terrain morphology which could cause hazard way of terrain-form processes. Seismic activity is one of the most important factors causing activation of geomorphological processes and contributing to the risk of dangerous situations. Earthquake even small force can provoke many catastrophic processes: landslides, mudslides, avalanches and mudflows, tsunami and others. Seismic gravitational phenomenons of different scale accompany almost all earthquakes of intensity 7-8 points and above, and some processes, such as avalanches, activated by seismic shocks intensity about 1-3 points. In this regard, we consider it important selection of high intensity seismic zones in

  4. Sedimentological and Geomorphological Effects of Reservoir Flushing: The Cachi Reservoir, Costa Rica, 1996

    DEFF Research Database (Denmark)

    Brandt, Anders; Swenning, Joar

    1999-01-01

    Physical geography, hydrology, geomorphology, sediment transport, erosion, sedimentation, dams, reservoirs......Physical geography, hydrology, geomorphology, sediment transport, erosion, sedimentation, dams, reservoirs...

  5. Watershed System Model: The Essentials to Model Complex Human-Nature System at the River Basin Scale

    Science.gov (United States)

    Li, Xin; Cheng, Guodong; Lin, Hui; Cai, Ximing; Fang, Miao; Ge, Yingchun; Hu, Xiaoli; Chen, Min; Li, Weiyue

    2018-03-01

    Watershed system models are urgently needed to understand complex watershed systems and to support integrated river basin management. Early watershed modeling efforts focused on the representation of hydrologic processes, while the next-generation watershed models should represent the coevolution of the water-land-air-plant-human nexus in a watershed and provide capability of decision-making support. We propose a new modeling framework and discuss the know-how approach to incorporate emerging knowledge into integrated models through data exchange interfaces. We argue that the modeling environment is a useful tool to enable effective model integration, as well as create domain-specific models of river basin systems. The grand challenges in developing next-generation watershed system models include but are not limited to providing an overarching framework for linking natural and social sciences, building a scientifically based decision support system, quantifying and controlling uncertainties, and taking advantage of new technologies and new findings in the various disciplines of watershed science. The eventual goal is to build transdisciplinary, scientifically sound, and scale-explicit watershed system models that are to be codesigned by multidisciplinary communities.

  6. INTERFEROMETRIC SYNTHETIC APERTURE RADAR (INSAR TECHNOLOGY AND GEOMORPHOLOGY INTERPRETATION

    Directory of Open Access Journals (Sweden)

    M. Maghsoudi

    2013-09-01

    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.

  7. Primary and complex stressors in polluted mediterranean rivers: Pesticide effects on biological communities

    Science.gov (United States)

    Ricart, Marta; Guasch, Helena; Barceló, Damià; Brix, Rikke; Conceição, Maria H.; Geiszinger, Anita; José López de Alda, Maria; López-Doval, Julio C.; Muñoz, Isabel; Postigo, Cristina; Romaní, Anna M.; Villagrasa, Marta; Sabater, Sergi

    2010-03-01

    SummaryWe examined the presence of pesticides in the Llobregat river basin (Barcelona, Spain) and their effects on benthic biological communities (invertebrates and diatoms). The Llobregat river is one of Barcelona's major drinking water resources. It has been highly polluted by industrial, agricultural, and urban wastewaters, and—as a typical Mediterranean river—is regularly subjected to periodic floods and droughts. Water scarcity periods result in reduced water flow and dilution capacity, increasing the potential environmental risk of pollutants. Seven sites were selected, where we analysed the occurrence of 22 pesticides (belonging to the classes of triazines, organophosphates, phenylureas, anilides, chloroacetanilides, acidic herbicides and thiocarbamates) in the water and sediment, and the benthic community structure. Biofilm samples were taken to measure several metrics related to both the algal and bacterial components of fluvial biofilms. Multivariate analyses revealed a potential relationship between triazine-type herbicides and the distribution of the diatom community, although no evidence of disruption in the invertebrate community distribution was found. Biofilm metrics were used as response variables rather than abundances of individual species to identify possible cause-effect relationships between pesticide pollution and biotic responses. Certain effects of organophosphates and phenylureas in both structural and functional aspects of the biofilm community were suggested, but the sensitivity of each metric to particular stressors must be assessed before we can confidently assign causality. Complemented with laboratory experiments, which are needed to confirm causality, this approach could be successfully incorporated into environmental risk assessments to better summarise biotic integrity and improve the ecological management.

  8. Eocene and Miocene extension, meteoric fluid infiltration, and core complex formation in the Great Basin (Raft River Mountains, Utah)

    Science.gov (United States)

    Methner, Katharina; Mulch, Andreas; Teyssier, Christian; Wells, Michael L.; Cosca, Michael A.; Gottardi, Raphael; Gebelin, Aude; Chamberlain, C. Page

    2015-01-01

    Metamorphic core complexes (MCCs) in the North American Cordillera reflect the effects of lithospheric extension and contribute to crustal adjustments both during and after a protracted subduction history along the Pacific plate margin. While the Miocene-to-recent history of most MCCs in the Great Basin, including the Raft River-Albion-Grouse Creek MCC, is well documented, early Cenozoic tectonic fabrics are commonly severely overprinted. We present stable isotope, geochronological (40Ar/39Ar), and microstructural data from the Raft River detachment shear zone. Hydrogen isotope ratios of syntectonic white mica (δ2Hms) from mylonitic quartzite within the shear zone are very low (−90‰ to −154‰, Vienna SMOW) and result from multiphase synkinematic interaction with surface-derived fluids. 40Ar/39Ar geochronology reveals Eocene (re)crystallization of white mica with δ2Hms ≥ −154‰ in quartzite mylonite of the western segment of the detachment system. These δ2Hms values are distinctively lower than in localities farther east (δ2Hms ≥ −125‰), where 40Ar/39Ar geochronological data indicate Miocene (18–15 Ma) extensional shearing and mylonitic fabric formation. These data indicate that very low δ2H surface-derived fluids penetrated the brittle-ductile transition as early as the mid-Eocene during a first phase of exhumation along a detachment rooted to the east. In the eastern part of the core complex, prominent top-to-the-east ductile shearing, mid-Miocene 40Ar/39Ar ages, and higher δ2H values of recrystallized white mica, indicate Miocene structural and isotopic overprinting of Eocene fabrics.

  9. Stochastic sensitivity analysis of nitrogen pollution to climate change in a river basin with complex pollution sources.

    Science.gov (United States)

    Yang, Xiaoying; Tan, Lit; He, Ruimin; Fu, Guangtao; Ye, Jinyin; Liu, Qun; Wang, Guoqing

    2017-12-01

    It is increasingly recognized that climate change could impose both direct and indirect impacts on the quality of the water environment. Previous studies have mostly concentrated on evaluating the impacts of climate change on non-point source pollution in agricultural watersheds. Few studies have assessed the impacts of climate change on the water quality of river basins with complex point and non-point pollution sources. In view of the gap, this paper aims to establish a framework for stochastic assessment of the sensitivity of water quality to future climate change in a river basin with complex pollution sources. A sub-daily soil and water assessment tool (SWAT) model was developed to simulate the discharge, transport, and transformation of nitrogen from multiple point and non-point pollution sources in the upper Huai River basin of China. A weather generator was used to produce 50 years of synthetic daily weather data series for all 25 combinations of precipitation (changes by - 10, 0, 10, 20, and 30%) and temperature change (increases by 0, 1, 2, 3, and 4 °C) scenarios. The generated daily rainfall series was disaggregated into the hourly scale and then used to drive the sub-daily SWAT model to simulate the nitrogen cycle under different climate change scenarios. Our results in the study region have indicated that (1) both total nitrogen (TN) loads and concentrations are insensitive to temperature change; (2) TN loads are highly sensitive to precipitation change, while TN concentrations are moderately sensitive; (3) the impacts of climate change on TN concentrations are more spatiotemporally variable than its impacts on TN loads; and (4) wide distributions of TN loads and TN concentrations under individual climate change scenario illustrate the important role of climatic variability in affecting water quality conditions. In summary, the large variability in SWAT simulation results within and between each climate change scenario highlights the uncertainty of

  10. How do animals communicate in complex hydrodynamic environments? Linking hydraulics and ecology in rivers.

    Science.gov (United States)

    Johnson, Matthew; Rice, Stephen

    2015-04-01

    turbulence exceeded that generated by living crayfish. This was particularly the case at low relative submergence. These results demonstrate the importance of the fluvial environment in controlling the transmission of sensory information and suggest that the ability of organisms to sense the presence of crayfish from their hydraulic signature is likely to be limited in many situations in rivers. Thus, animals in rivers may have to rely on other senses, such as sight or hearing, especially where depth is low relative to substrate roughness and where velocities are relatively high.

  11. Geomorphology and habitat diversity in the Pantanal.

    Science.gov (United States)

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

    2011-04-01

    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.

  12. Geomorphology: now a more quantitative science

    International Nuclear Information System (INIS)

    Lal, D.

    1995-01-01

    Geomorphology, one of the oldest branches of planetary science, is now growing into a quantitative field with the development of a nuclear method capable of providing numeric time controls on a great variety of superficial processes. The method complement the conventional dating methods, e.g. 40 K/ 40 Ar, 87 Rb/ 87 Sr, by providing information on geomorphic processes., e.g. the dwell times of rocks on the earth's surface with strict geometrical constraints; e.g., rates of physical and chemical weathering in the past, chronology of events associated with glaciation, etc. This article attempts to discuss the new possibilities that now exist for studying a wide range of geomorphic processes, with examples of some specific isotopic changes that allow one to model glacial chronology, and evolutionary histories of alluvial fans and sand dunes. (author). 9 refs., 3 figs., 4 tabs

  13. Correlation between seismicity and geomorphology in Dingxi Basin, Gansu Province, China

    Directory of Open Access Journals (Sweden)

    Li Xue

    2013-01-01

    Full Text Available A M6.6 earthquake occurred on July 22, 2013 at Dingxi Basin in Gansu Province within the tectonially expanding northeastern margin of the Qinghai-Tibet Plateau. We analyzed the geomorphological features of the Dingxi Basin by using remote sensing technology and compared them with local seismic activity. We found that most of the river basins are at the robust stage of development and that the major local rivers and the development of some basins boundaries are controlled by the seismic faults. Among four zones identified to have significant tectonic activities, the northwestly-oriented one located in the south has the highest seismic activity, and it is where the M6. 6 earthquake occurrred.

  14. Rethinking the longitudinal stream temperature paradigm: region-wide comparison of thermal infrared imagery reveals unexpected complexity of river temperatures

    Science.gov (United States)

    We used an extensive dataset of remotely sensed summertime river temperature to compare longitudinal profiles (temperature versus distance) for 54 rivers in the Pacific Northwest. We evaluated (1) how often profiles fit theoretical expectations of asymptotic downstream warming, a...

  15. Terrace system of the middle and lower Sázava River

    Czech Academy of Sciences Publication Activity Database

    Balatka, B.; Štěpančíková, Petra

    2006-01-01

    Roč. 6, č. 1 (2006), s. 69-81 ISSN 1335-9541 Institutional research plan: CEZ:AV0Z30460519 Keywords : fluvial terrace system * geomorphological evolution * Sázava River Subject RIV: DB - Geology ; Mineralogy

  16. Adaptation Challenges in Complex River Basins: Lessons Learned and Unlearned for the Colorado

    Science.gov (United States)

    Pulwarty, R. S.

    2008-12-01

    Climate variations affect the function and operation of existing water infrastructure - including hydropower, structural flood defenses, drainage and irrigation systems - as well as water management practices in support of efficiency and environmental needs. Selected basins around the world, including the Colorado, show agreements in model projections of increasing aridity. Adverse effects of climate change on freshwater systems aggravate the impacts of other stresses, such as population growth, changing economic activity, land-use change and urbanization and most importantly upstream-downstream winners and losers. Thus current water management practices may not be robust enough to cope with the impacts of climate change on water supply reliability. In many locations, water management does not even satisfactorily cope with current climate variability, so that large flood and drought-related environmental and economic damages occur on seasonal to decadal timescales. The recently released IPCC Technical Paper notes that adaptation procedures and risk management practices that incorporate projected hydrological changes with related uncertainties are being developed in some countries and regions.In this presentation we will review the challenges and lessons provided in drought and water resources management and optimization in the context of climate variability and projected change in the Western U.S., the European Union (including the Iberian Peninsula), the Murray-Darling Basin, and elsewhere. Since the release of the IPCC report several of the authors (including the presenter) have held meetings on comparative assessments of adaptation and its challenges in interstate and international river basins. As a first step, improved incorporation of information about current climate variability into water-related management could assist adaptation to longer-term climate change impacts. Future adaptations include technical changes that improve water use efficiency, demand

  17. Water Accounting Plus (WA+ – a water accounting procedure for complex river basins based on satellite measurements

    Directory of Open Access Journals (Sweden)

    P. Karimi

    2013-07-01

    Full Text Available Coping with water scarcity and growing competition for water among different sectors requires proper water management strategies and decision processes. A pre-requisite is a clear understanding of the basin hydrological processes, manageable and unmanageable water flows, the interaction with land use and opportunities to mitigate the negative effects and increase the benefits of water depletion on society. Currently, water professionals do not have a common framework that links depletion to user groups of water and their benefits. The absence of a standard hydrological and water management summary is causing confusion and wrong decisions. The non-availability of water flow data is one of the underpinning reasons for not having operational water accounting systems for river basins in place. In this paper, we introduce Water Accounting Plus (WA+, which is a new framework designed to provide explicit spatial information on water depletion and net withdrawal processes in complex river basins. The influence of land use and landscape evapotranspiration on the water cycle is described explicitly by defining land use groups with common characteristics. WA+ presents four sheets including (i a resource base sheet, (ii an evapotranspiration sheet, (iii a productivity sheet, and (iv a withdrawal sheet. Every sheet encompasses a set of indicators that summarise the overall water resources situation. The impact of external (e.g., climate change and internal influences (e.g., infrastructure building can be estimated by studying the changes in these WA+ indicators. Satellite measurements can be used to acquire a vast amount of required data but is not a precondition for implementing WA+ framework. Data from hydrological models and water allocation models can also be used as inputs to WA+.

  18. Response of bankfull discharge of the Inner Mongolia Yellow River ...

    Indian Academy of Sciences (India)

    the flood and sediment transport capacity of a river channel. It is based on the ...... Eng. 39 680–687 (in Chinese). Wu B S and Zhang Y F 2007 Law of along-course chang- ... load in the Lower Yellow River; Geomorphology 100(3–4). 366–376.

  19. Baseflow vs floods: Linking geomorphology and ecology by blurring disciplinary and ecosystem boundaries

    Science.gov (United States)

    Doyle, M. W.; Stanley, E. H.; Small, M.

    2011-12-01

    Linking ideas between geomorphology and ecology has led to some of the formative concepts in river science. These past developments suggest opportunities for greater conceptual alignment novel research agenda via continued cross-fertilization. Hydrologic variability provides a notable example of both intellectual divergence and convergence between geomorphologists and ecologists. Conceptually, both disciplines have recognition of the importance the "natural flow regime." Yet geomorphologists tend to focus on rare events which are formative in sculpting the landscape, while ecologists often emphasize baseflow conditions when biological production and biochemical processes (transformation) dominate over hydrologic transport. Thus, perceptions of river systems begin from two different starting points for these two disciplines. These different perspectives in turn lead to presumed appropriate spatial or temporal scale at which studies should be conducted and can influence site selection. Geomorphologists are more likely to work in rivers subject to pronounced physical change to gain insight to geomorphic processes, and to limit their work to sites with sufficient historic data to analyze change. Conversely, ecologists are likely to select less dynamic physical templates - both in space and time- to allow greater focus on biotic processes. Thus, the basic geography of the disciplines can be surprisingly divergent, as can be the basic timescales of studies. Recent developments in incorporating hydrologic variability into nutrient spiraling have been important in linking geomorphology and stream ecology. Moving from baseflow to more full inclusion of the hydrologic spectrum has dramatically increased understanding of stream biogeochemistry, but it has also drawn in more sophisticated treatments of hydrology into stream biogeochemistry and ecology. This relative success of hydrologic variability and nutrient spiraling studies raises the question of what other opportunities

  20. Contrasting the roles of section length and instream habitat enhancement for river restoration success

    NARCIS (Netherlands)

    Hering, Daniel; Aroviita, Jukka; Baattrup-Pedersen, Annette; Brabec, Karel; Buijse, Tom; Ecke, Frauke; Friberg, Nikolai; Gielczewski, Marek; Januschke, Kathrin; Köhler, Jan; Kupilas, Benjamin; Lorenz, Armin W.; Muhar, Susanne; Paillex, Amael; Poppe, Michaela; Schmidt, Torsten; Schmutz, Stefan; Vermaat, Jan; Verdonschot, Piet F.M.; Verdonschot, Ralf C.M.; Wolter, Christian; Kail, Jochem

    2015-01-01

    Restoration of river hydromorphology often has limited detected effects on river biota. One frequently discussed reason is that the restored river length is insufficient to allow populations to develop and give the room for geomorphological processes to occur. We investigated ten pairs of

  1. 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...

  2. Laser altimetry and terrain analysis: A revolution in geomorphology

    NARCIS (Netherlands)

    Anders, N.; Seijmonsbergen, H.

    2008-01-01

    Terrain analysis in geomorphology has undergone a serious quantitative revolution over recent decades. Lidar information has been efficiently used to automatically classify discrete landforms, map forest structures, and provide input for models simulating landscape development, e.g. channel incision

  3. Academician Ivan Gams and his influence on development of geomorphology in the Republic of Croatia

    Directory of Open Access Journals (Sweden)

    Andrija Bognar

    2003-12-01

    Full Text Available The author presents the role of academician Ivan Gams in the reorientation and modernization of Croatian geomorphology during 1970's and 1980's. The causes for losing contact with contemporary development of geomorphology in the world are analyzed in detail, and the way of reestablishing the former reputation and importance of Croatian geomorphology is presented, especially through the implementation of detailed geomorphological mapping, new methods of geomorphological investigation and education of younger scientific personnel at the university of Zagreb.

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

    Science.gov (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.

    2016-12-01

    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. GIS-study and new Geomorphologic Mapping of Phobos

    Science.gov (United States)

    Kokhanov, Alexander; Lorenz, Cyrill; Karachevtseva, Irina

    2016-04-01

    Using raw images and processed orthoimages, obtained from "Mars Express", we have created a new GIS-catalog of grooves. During analysis, new grooves, not identified in earlier mapping attempts, were detected. For craters study the previously created catalog of craters with D >200 m [1] was used. The spatial orientation of individual grooves was estimated, which allows us to group them into several sets. All grooves in the catalog were divided into three morphological types: gutters (simple line depressions), chains of contiguous funnels, chains of noncontigual funnels. Studying craters we paid attention to its inner and outer morphology. The shape of some craters is different from the isometric. Among them were identified elliptical and polygonal craters. The study of inner morphology showed, that there prevails simple bowl-shaped craters. Also we identified a small population of craters with complex internal morphology [2], which, by analogy with similar lunar craters [3], divided into flat-bottomed, with a central mound and concentric craters. Moreover, based on elevation data, obtained from global digital elevation model [4] and calculation of relative depth, craters with D >2 km by the stage of degradation were classified. Focusing on a combination of grooves and craters, we have identified 15 morphological regions. A morphological unit was defined as a region with a certain type of relief, which differs from surrounding areas by the presence, orientation and spatial relations of groove systems and large craters (over 200 m). Each region may have its own geological history and consequently, specific history of regolith exposure. Finally, two geomorphologic maps of Phobos were created. One map represents the spatial distributions of grooves including their classifications by morphological types. The identified morphological regions are shown, and relief characteristics of these regions are briefly described. Geomorphologic map of craters shows the spatial

  6. Structure and contents of a new geomorphological GIS database linked to a geomorphological map — With an example from Liden, central Sweden

    NARCIS (Netherlands)

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

    2008-01-01

    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

  7. Syn-extensional plutonism and peak metamorphism in the albion-raft river-grouse creek metamorphic core complex

    Science.gov (United States)

    Strickland, A.; Miller, E.L.; Wooden, J.L.; Kozdon, R.; Valley, J.W.

    2011-01-01

    The Cassia plutonic complex (CPC) is a group of variably deformed, Oligocene granitic plutons exposed in the lower plate of the Albion-Raft River- Grouse Creek (ARG) metamorphic core complex of Idaho and Utah. The plutons range from granodiorite to garnet-bearing, leucogranite, and during intrusion, sillimanite- grade peak metamorphism and ductile attenuation occurred in the country rocks and normal-sense, amphibolite-grade deformation took place along the Middle Mountain shear zone. U-Pb zircon geochronology from three variably deformed plutons exposed in the lower plate of the ARG metamorphic core complex revealed that each zircon is comprised of inherited cores (dominantly late Archean) and Oligocene igneous overgrowths. Within each pluton, a spread of concordant ages from the Oligocene zircon overgrowths is interpreted as zircon recycling within a long-lived magmatic system. The plutons of the CPC have very low negative whole rock ??Nd values of -26 to -35, and initial Sr values of 0.714 to 0.718, consistent with an ancient, crustal source. Oxygen isotope ratios of the Oligocene zircon overgrowths from the CPC have an average ??18O value of 5.40 ?? 0.63 permil (2SD, n = 65) with a slight trend towards higher ??18O values through time. The ??18O values of the inherited cores of the zircons are more variable at 5.93 ?? 1.51 permil (2SD, n = 29). Therefore, we interpret the plutons of the CPC as derived, at least in part, from melting Archean crust based on the isotope geochemistry. In situ partial melting of the exposed Archean basement that was intruded by the Oligocene plutons of the CPC is excluded as the source for the CPC based on field relationships, age and geochemistry. Correlations between Ti and Hf concentrations in zircons from the CPC suggest that the magmatic system may have become hotter (higher Ti concentration in zircon) and less evolved (lower Hf in zircon concentration) through time. Therefore, the CPC represents prolonged or episodic magmatism

  8. Applying NASA Imaging Radar Datasets to Investigate the Geomorphology of the Amazon's Planalto

    Science.gov (United States)

    McDonald, K. C.; Campbell, K.; Islam, R.; Alexander, P. M.; Cracraft, J.

    2016-12-01

    The Amazon basin is a biodiversity rich biome and plays a significant role into shaping Earth's climate, ocean and atmospheric gases. Understanding the history of the formation of this basin is essential to our understanding of the region's biodiversity and its response to climate change. During March 2013, the NASA/JPL L-band polarimetric airborne imaging radar, UAVSAR, conducted airborne studies over regions of South America including portions of the western Amazon basin. We utilize UAVSAR imagery acquired during that time 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 its relationship to geologic processes through deep time. We employ UAVSAR data collections to assess the utility of these high quality imaging radar data for use in identifying geomorphologic features and vegetation communities within the context of improving the understanding of evolutionary processes, and their utility in aiding interpretation of datasets from Earth-orbiting satellites to support a basin-wide characterization across the Amazon. We derive maps of landcover and river branching structure from UAVSAR imagery. We compare these maps to those derived using imaging radar datasets from the Japanese Space Agency's ALOS PALSAR and Digital Elevation Models (DEMs) from NASA's Shuttle Radar Topography Mission (SRTM). Results provide an understanding of the underlying geomorphology of the Amazon planalto as well as its relationship to geologic processes and will support interpretation of the evolutionary history of the Amazon Basin. Portions of this work have been carried out within the framework of the ALOS Kyoto & Carbon Initiative. PALSAR data were provided by JAXA/EORC and the Alaska Satellite Facility.This work is carried out with support from the NASA Biodiversity Program and the NSF DIMENSIONS of Biodiversity Program.

  9. Regional controls on geomorphology, hydrology, and ecosystem integrity in the Orinoco Delta, Venezuela

    Science.gov (United States)

    Warne, A.G.; Meade, R.H.; White, W.A.; Guevara, E.H.; Gibeaut, J.; Smyth, R.C.; Aslan, A.; Tremblay, T.

    2002-01-01

    Interacting river discharge, tidal oscillation, and tropical rainfall across the 22,000 km2 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 Rio 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. ?? 2002 Elsevier Science B.V. All rights reserved.

  10. Geomorphological context of the basins of Northwestern Peninsular Malaysia

    Science.gov (United States)

    Sautter, Benjamin; Pubellier, Manuel; Menier, David

    2014-05-01

    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

  11. The ESPAT tool: a general-purpose DSS shell for solving stochastic optimization problems in complex river-aquifer systems

    Science.gov (United States)

    Macian-Sorribes, Hector; Pulido-Velazquez, Manuel; Tilmant, Amaury

    2015-04-01

    Stochastic programming methods are better suited to deal with the inherent uncertainty of inflow time series in water resource management. However, one of the most important hurdles in their use in practical implementations is the lack of generalized Decision Support System (DSS) shells, usually based on a deterministic approach. The purpose of this contribution is to present a general-purpose DSS shell, named Explicit Stochastic Programming Advanced Tool (ESPAT), able to build and solve stochastic programming problems for most water resource systems. It implements a hydro-economic approach, optimizing the total system benefits as the sum of the benefits obtained by each user. It has been coded using GAMS, and implements a Microsoft Excel interface with a GAMS-Excel link that allows the user to introduce the required data and recover the results. Therefore, no GAMS skills are required to run the program. The tool is divided into four modules according to its capabilities: 1) the ESPATR module, which performs stochastic optimization procedures in surface water systems using a Stochastic Dual Dynamic Programming (SDDP) approach; 2) the ESPAT_RA module, which optimizes coupled surface-groundwater systems using a modified SDDP approach; 3) the ESPAT_SDP module, capable of performing stochastic optimization procedures in small-size surface systems using a standard SDP approach; and 4) the ESPAT_DET module, which implements a deterministic programming procedure using non-linear programming, able to solve deterministic optimization problems in complex surface-groundwater river basins. The case study of the Mijares river basin (Spain) is used to illustrate the method. It consists in two reservoirs in series, one aquifer and four agricultural demand sites currently managed using historical (XIV century) rights, which give priority to the most traditional irrigation district over the XX century agricultural developments. Its size makes it possible to use either the SDP or

  12. Effective utilization of geomorphology in uranium exploration: a success story from Meghalaya, northeast India

    International Nuclear Information System (INIS)

    Mamallan, R.; Awati, A.B.; Gupta, K.R.; Kak, S.N.

    1995-01-01

    The southern fringe of Meghalaya plateau displays a spectacular development of erosional landforms in the thick sedimentary cover of Cretaceous-Tertiary formations. Mahadek formation, the lower member of this sequence, comprises both continental and marginal marine sediments while all the overlying formations are mainly of marine origin. In the study area all the tertiary formations are eroded away, leaving exposed the continental part of the Mahadek formation, which comprises channel-filled and floodplain sediments. Geomorphologically, both these units express themselves as cuestas but significant textural differences were observed, enabling us to discriminate them in aerial photographs. It is known that the channel-filled sedimentary unit incorporates many favourable geological and geochemical characters to host uranium mineralization. The domiasiat uranium deposit occurs in this unit only. By virtue of its distinct geomorphology, three domains of channel-filled sediments were demarcated in aerial photographs. Follow-up radiometric field checks on one of these domains, near the confluence of Wah Blei and Kynshiang rivers, have led to the discovery of significant uranium occurrences, opening up promising new avenues for uranium exploration in Megahalya. (author). 4 refs., 2 figs

  13. The human role in changing river channels

    Science.gov (United States)

    Gregory, K. J.

    2006-09-01

    , because of complex response and contingency. The ways in which changes in cross-section relate to reach and network changes are less clear, despite investigations showing the distribution of changes along segmented channels. When considering the human role in relation to changing river channels, at least five challenges persist. First, because prediction of the nature and amount of likely change at a particular location is not certain, and because the contrasting responses of humid and arid systems needs to be considered, modelling is required to reduce uncertainty, as was first emphasised by Burkham [Burkham, D.E., 1981. Uncertainties resulting from changes in river form. American Society Civil Engineers Proceedings, Journal Hydraulics Division 107, 593-610.]. Second, feedback effects incorporated within the relationship between changes at channel, reach and network scales can have considerable implications, especially because changes now evident may have occurred, or have been initiated, under different environmental conditions. Third, consideration of global climate change is imperative when considering channel sensitivity and responses to threshold conditions. Fourth, channel design involving geomorphology should now be an integral part of restoration procedures. This requires, fifthly, greater awareness of different cultures as a basis for understanding constraints imposed by legislative frameworks. Better understanding of the ways in which the perception of the human role in changing river channels varies with culture as well as varying over time should enhance application of design for river channel landscapes.

  14. Possibilities for a valorisation of geomorphologic research deliverables

    Science.gov (United States)

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

    2009-04-01

    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

  15. Impacts of climate change on TN load and its control in a River Basin with complex pollution sources.

    Science.gov (United States)

    Yang, Xiaoying; Warren, Rachel; He, Yi; Ye, Jinyin; Li, Qiaoling; Wang, Guoqing

    2018-02-15

    It is increasingly recognized that climate change could affect the quality of water through complex natural and anthropogenic mechanisms. Previous studies on climate change and water quality have mostly focused on assessing its impact on pollutant loads from agricultural runoff. A sub-daily SWAT model was developed to simulate the discharge, transport, and transformation of nitrogen from all known anthropogenic sources including industries, municipal sewage treatment plants, concentrated and scattered feedlot operations, rural households, and crop production in the Upper Huai River Basin. This is a highly polluted basin with total nitrogen (TN) concentrations frequently exceeding Class V of the Chinese Surface Water Quality Standard (GB3838-2002). Climate change projections produced by 16 Global Circulation Models (GCMs) under the RCP 4.5 and RCP 8.5 scenarios in the mid (2040-2060) and late (2070-2090) century were used to drive the SWAT model to evaluate the impacts of climate change on both the TN loads and the effectiveness of three water pollution control measures (reducing fertilizer use, constructing vegetative filter strips, and improving septic tank performance) in the basin. SWAT simulation results have indicated that climate change is likely to cause an increase in both monthly average and extreme TN loads in February, May, and November. The projected impact of climate change on TN loads in August is more varied between GCMs. In addition, climate change is projected to have a negative impact on the effectiveness of septic tanks in reducing TN loads, while its impacts on the other two measures are more uncertain. Despite the uncertainty, reducing fertilizer use remains the most effective measure for reducing TN loads under different climate change scenarios. Meanwhile, improving septic tank performance is relatively more effective in reducing annual TN loads, while constructing vegetative filter strips is more effective in reducing annual maximum monthly

  16. Structure and contents of a new geomorphological GIS database linked to a geomorphological map — With an example from Liden, central Sweden

    Science.gov (United States)

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

    2008-03-01

    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.

  17. Bio-geomorphology and resilience thinking: Common ground and challenges

    Science.gov (United States)

    Thoms, Martin C.; Meitzen, Kimberly M.; Julian, Jason P.; Butler, David R.

    2018-03-01

    Geomorphology plays a fundamental role in shaping and maintaining landscapes, as well as influencing the social and ecological systems that occupy and utilize these landscapes. In turn, social-ecological systems can have a profound influence on geomorphic forms and processes. These interactions highlight the tightly coupled nature of geomorphic systems. Over the past decade, there has been a proliferation of research at the interface of geomorphology and resilience thinking, and the 2017 Binghamton Symposium brought together leading researchers from both communities to address mutual concerns and challenges of these two disciplines. This paper reviews some of the key intersections between the disciplines of bio-geomorphology and resilience thinking, and the papers presented at the symposium. The papers in this volume illustrate the current status of the disciplines, the difficulties in bridging the disciplines, and the issues that are emerging as research priorities.

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

    Science.gov (United States)

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

    2014-05-01

    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

  19. Geomorphology and Depositional Subenvironments of Gulf Islands National Seashore, Mississippi

    Science.gov (United States)

    Morton, Robert A.; Rogers, Bryan E.

    2010-01-01

    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

  20. The geomorphology of wetlands in drylands: Resilience, nonresilience, or …?

    Science.gov (United States)

    Tooth, Stephen

    2018-03-01

    Over the last decade, much attention has focused on wetland resilience to disturbances such as extreme weather events, longer climate change, and human activities. In geomorphology and cognate disciplines, resilience is defined in various ways and has physical and socioeconomic dimensions but commonly is taken to mean the ability of a system to (A) withstand disturbance, (B) recover from disturbance, or (C) adapt and evolve in response to disturbance to a more desirable (e.g., stable) configuration. Most studies of wetland resilience have tended to focus on the more-or-less permanently saturated humid region wetlands, but whether the findings can be readily transferred to wetlands in drylands remains unclear. Given the natural climatic variability and overall strong moisture deficit characteristic of drylands, are such wetlands likely to be more resilient or less resilient? Focusing on wetlands in the South African drylands, this paper uses existing geomorphological, sedimentological, and geochronological data sets to provide the spatial (up to 50 km2) and temporal (late Quaternary) framework for an assessment of geomorphological resilience. Some wetlands have been highly resilient to environmental (especially climate) change, but others have been nonresilient with marked transformations in channel-floodplain structure and process connectivity having been driven by natural factors (e.g., local base-level fall, drought) or human activities (e.g., channel excavation, floodplain drainage). Key issues related to the assessment of wetland resilience include channel-floodplain dynamics in relation to geomorphological thresholds, wetland geomorphological 'life cycles', and the relative roles of natural and human activities. These issues raise challenges for the involvement of geomorphologists in the practical application of the resilience concept in wetland management. A key consideration is how geomorphological resilience interfaces with other dimensions of resilience

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

    Directory of Open Access Journals (Sweden)

    Langgeng Wahyu Santosa

    2013-07-01

    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.

  2. Morphology and spacing of river meander scrolls

    Science.gov (United States)

    Strick, Robert J. P.; Ashworth, Philip J.; Awcock, Graeme; Lewin, John

    2018-06-01

    Many of the world's alluvial rivers are characterised by single or multiple channels that are often sinuous and that migrate to produce a mosaicked floodplain landscape of truncated scroll (or point) bars. Surprisingly little is known about the morphology and geometry of scroll bars despite increasing interest from hydrocarbon geoscientists working with ancient large meandering river deposits. This paper uses remote sensing imagery, LiDAR data-sets of meandering scroll bar topography, and global coverage elevation data to quantify scroll bar geometry, anatomy, relief, and spacing. The analysis focuses on preserved scroll bars in the Mississippi River (USA) floodplain but also compares attributes to 19 rivers of different scale and depositional environments from around the world. Analysis of 10 large scroll bars (median area = 25 km2) on the Mississippi shows that the point bar deposits can be categorised into three different geomorphological units of increasing scale: individual 'scrolls', 'depositional packages', and 'point bar complexes'. Scroll heights and curvatures are greatest near the modern channel and at the terminating boundaries of different depositional packages, confirming the importance of the formative main channel on subsequent scroll bar relief and shape. Fourier analysis shows a periodic variation in signal (scroll bar height) with an average period (spacing) of 167 m (range 150-190 m) for the Mississippi point bars. For other rivers, a strong relationship exists between the period of scroll bars and the adjacent primary channel width for a range of rivers from 55 to 2042 mis 50% of the main channel width. The strength of this correlation over nearly two orders of magnitude of channel size indicates a scale independence of scroll bar spacing and suggests a strong link between channel migration and scroll bar construction with apparent regularities despite different flow regimes. This investigation of meandering river dynamics and floodplain

  3. Effects of 4D-Var Data Assimilation Using Remote Sensing Precipitation Products in a WRF Model over the Complex Terrain of an Arid Region River Basin

    Directory of Open Access Journals (Sweden)

    Xiaoduo Pan

    2017-09-01

    Full Text Available Individually, ground-based, in situ observations, remote sensing, and regional climate modeling cannot provide the high-quality precipitation data required for hydrological prediction, especially over complex terrains. Data assimilation techniques can be used to bridge the gap between observations and models by assimilating ground observations and remote sensing products into models to improve precipitation simulation and forecasting. However, only a small portion of satellite-retrieved precipitation products assimilation research has been implemented over complex terrains in an arid region. Here, we used the weather research and forecasting (WRF model to assimilate two satellite precipitation products (The Tropical Rainfall Measuring Mission: TRMM 3B42 and Fengyun-2D: FY-2D using the 4D-Var data assimilation method for a typical inland river basin in northwest China’s arid region, the Heihe River Basin, where terrains are very complex. The results show that the assimilation of remote sensing precipitation products can improve the initial WRF fields of humidity and temperature, thereby improving precipitation forecasting and decreasing the spin-up time. Hence, assimilating TRMM and FY-2D remote sensing precipitation products using WRF 4D-Var can be viewed as a positive step toward improving the accuracy and lead time of numerical weather prediction models, particularly over regions with complex terrains.

  4. Numerical modelling of river morphodynamics: Latest developments and remaining challenges

    Science.gov (United States)

    Siviglia, Annunziato; Crosato, Alessandra

    2016-07-01

    Numerical morphodynamic models provide scientific frameworks for advancing our understanding of river systems. The research on involved topics is an important and socially relevant undertaking regarding our environment. Nowadays numerical models are used for different purposes, from answering questions about basic morphodynamic research to managing complex river engineering problems. Due to increasing computer power and the development of advanced numerical techniques, morphodynamic models are now more and more used to predict the bed patterns evolution to a broad spectrum of spatial and temporal scales. The development and the success of application of such models are based upon a wide range of disciplines from applied mathematics for the numerical solution of the equations to geomorphology for the physical interpretation of the results. In this light we organized this special issue (SI) soliciting multidisciplinary contributions which encompass any aspect needed for the development and applications of such models. Most of the papers in the SI stem from contributions to session HS9.5/GM7.11 on numerical modelling and experiments in river morphodynamics at the European Geosciences Union (EGU) General Assembly held in Vienna, April 27th to May 2nd 2014.

  5. Organic complexation and translocation of ferric iron in podzols of the Negro River watershed. Separation of secondary Fe species from Al species

    Science.gov (United States)

    Fritsch, E.; Allard, Th.; Benedetti, M. F.; Bardy, M.; do Nascimento, N. R.; Li, Y.; Calas, G.

    2009-04-01

    The development of podzols in lateritic landscapes of the upper Amazon basin contributes to the exportation of organic carbon and associated metals in the black waters of the Negro River watershed. We have investigated the distribution of Fe III in the clay-size fraction of eight organic-rich horizons of waterlogged plateau podzols, to unravel the weathering conditions and mechanisms that control its transfer to the rivers. The speciation and amount of Fe III stored in residual mineral phases of laterites, or bound to organic compounds of weakly and well-expressed podzols, were determined by electron paramagnetic resonance spectroscopy combined with chemical analyses. Reducing conditions restrict the production of organo-Fe complexes in the subsoil B-horizons of waterlogged podzols and most of the Fe 2+ released from the dissolution of Fe-oxides is exported to the rivers via the perched groundwater. However, significant amounts of diluted Fe III bound to organic ligands (Fe IIIOM) and nano Fe-oxides are produced at the margin of the depression in the topsoil A horizons of weakly expressed podzols due to shorter periods of anoxia. The downward translocation of organically bound metals from topsoil A to subsoil B-horizons of podzols occurs in shorter distances for Fe than it does for Al. This separation of secondary Fe species from Al species is attributed to the physical fractionation of their organic carriers in texture contrasted B-horizons of podzols, as well as to the effect of pH on metal speciation in soil solutions and metal binding onto soil organic ligands (mostly for Al). This leads us to consider the topsoil A horizons of weakly expressed podzols, as well as the subsoil Bh horizon of better-expressed ones, as the main sources for the transfer of Fe IIIOM to the rivers. The concentration of Fe IIIOM rises from soil sources to river colloids, suggesting drastic biogeochemical changes in more oxygenated black waters of the Negro River watershed. The

  6. Development of a transient, lumped hydrologic model for geomorphologic units in a geomorphology based rainfall-runoff modelling framework

    Science.gov (United States)

    Vannametee, E.; Karssenberg, D.; Hendriks, M. R.; de Jong, S. M.; Bierkens, M. F. P.

    2010-05-01

    We propose a modelling framework for distributed hydrological modelling of 103-105 km2 catchments by discretizing the catchment in geomorphologic units. Each of these units is modelled using a lumped model representative for the processes in the unit. Here, we focus on the development and parameterization of this lumped model as a component of our framework. The development of the lumped model requires rainfall-runoff data for an extensive set of geomorphological units. Because such large observational data sets do not exist, we create artificial data. With a high-resolution, physically-based, rainfall-runoff model, we create artificial rainfall events and resulting hydrographs for an extensive set of different geomorphological units. This data set is used to identify the lumped model of geomorphologic units. The advantage of this approach is that it results in a lumped model with a physical basis, with representative parameters that can be derived from point-scale measurable physical parameters. The approach starts with the development of the high-resolution rainfall-runoff model that generates an artificial discharge dataset from rainfall inputs as a surrogate of a real-world dataset. The model is run for approximately 105 scenarios that describe different characteristics of rainfall, properties of the geomorphologic units (i.e. slope gradient, unit length and regolith properties), antecedent moisture conditions and flow patterns. For each scenario-run, the results of the high-resolution model (i.e. runoff and state variables) at selected simulation time steps are stored in a database. The second step is to develop the lumped model of a geomorphological unit. This forward model consists of a set of simple equations that calculate Hortonian runoff and state variables of the geomorphologic unit over time. The lumped model contains only three parameters: a ponding factor, a linear reservoir parameter, and a lag time. The model is capable of giving an appropriate

  7. Learning Desert Geomorphology Virtually versus in the Field

    Science.gov (United States)

    Stumpf, Richard J., II; Douglass, John; Dorn, Ronald I.

    2008-01-01

    Statistical analyses of pre-test and post-test results, as well as qualitative insight obtained by essays, compared introductory physical geography college students who learned desert geomorphology only virtually, in the field and both ways. With the exception of establishing geographic context, the virtual field trip was statistically…

  8. Introducing Field-Based Geologic Research Using Soil Geomorphology

    Science.gov (United States)

    Eppes, Martha Cary

    2009-01-01

    A field-based study of soils and the factors that influence their development is a strong, broad introduction to geologic concepts and research. A course blueprint is detailed where students design and complete a semester-long field-based soil geomorphology project. Students are first taught basic soil concepts and to describe soil, sediment and…

  9. Geomorphological Characterization of Atenquique Basin in the Eastern Sector of the Volcan-Nevado-Colima, Jalisco, Mexico, As an Input to the Risk Assessment of Debris Flows.

    Science.gov (United States)

    Flores-Pena, S.; Suarez-Plascencia, C.

    2014-12-01

    The Atenquique river basin drains the eastern sector of the Volcanic Complex (VC) Volcan-Nevado de Colima, located on the border of the states of Jalisco and Colima. To use the digital geomorphological analysis 1:50000 scale mapping provided by INEGI and Landsat images, manipulating it in ArcGIS 10.2 developing the DEM that was the basis for morphometric characterization. The results show that the basin is divided into five sub-basins, with the main Atenquique (SAT) and Arroyo Seco (SAS), calculating the compactness coefficient (Kc) and the coefficient of sinuosity indicate that SAT is the most prone to floods due to straight and slightly sinuous channels. However, the density of dissection shows a more developed drainage network on the SAT, with slopes up to 84° and 600 m deep. The drainage basin has its source at an altitude of 4260 m and its mouth is in the Tuxpan River at 1040 m, which has a relative height of 2800 m; has a funnel-shaped elongated west-east, its outstanding average in the sector are Mountain 44° and 10° the piedmont. The SAT has a total area of 81.8 km2, with a dendritic river network, where the first order streams reach an 82.99%, and second order streams are the 13.4% of the total, these values show that most of the slopes of the basin have incipient development valleys and steep slopes. The basin has had 3 debris flows in recent 58 years; these are formed by large volumes of rock and mud that covered the town of Atenquique and paper mill located at the mouth of the Tuxpan River, caused deaths and significant economic damage. Its genesis is associated with the end of the summer rainy season, so he also worked in the hydrological analysis in order to determine the volume of runoff in the basin. The results of this work are used as input for the determining the risk levels in the study area, and may also be used by the municipality of Tuxpan, in order to define policies to manage risk and reduce future risks to the industrial town of

  10. Performance Assessment/Composite Analysis Modeling to Support a Holistic Strategy for the Closure of F Area, a Large Nuclear Complex at the Savannah River Site

    International Nuclear Information System (INIS)

    COOK, JAMES

    2004-01-01

    A performance-based approach is being used at the Savannah River Site to close the F area Complex. F Area consists of a number of large industrial facilities including plutonium separations, uranium fuel fabrication, tanks for storing high level waste and a number of smaller operations. A major part of the overall closure strategy is the use of techniques derived from the Performance Assessment and Composite Analysis requirements for low level waste disposal at DOE sites. This process will provide a means of demonstrating the basis for deactivation, decommissioning and closure decisions to management, stakeholders and regulators

  11. Bar deposition in glacial outburst floods: scaling, post-flood reworking, and implications for the geomorphological and sedimentary record

    Science.gov (United States)

    Marren, Philip

    2016-04-01

    The appearance of a flood deposit in the geomorphological and sedimentary record is a product of both the processes operating during the flood, and those that occur afterwards and which overprint the deposit with a record of 'normal' processes. This paper describes the creation and modification of jökulhlaup barforms in the Skeiðará river, relating the changes to post-flood fluvial processes and glacier retreat. Large compound bars formed from the amalgamation of unit bars up to 1.5 km long. Nearly half of the total discharge of the November 1996 jökulhlaup on Skeiðarársandur was discharged through the Skeiðará river. The flood deposits have been extensively reworked since, up until 2009 when the channel was abandoned, effectively leaving the Skeiðará as a terrace, when retreat of Skeiðarárjökull directed meltwater to the adjacent Gígjukvísl river system. Large compound bars formed in the flood channel, with their location governed by the macro-scale topography of the flood channel, and their size by upstream channel width in accordance with bar-scaling theory. Jökulhlaup bars are therefore scale invariant and formed in a similar fashion to braid bars in non-jökulhlaup braided rivers. Post-flood fragmentation and reworking of the bars consistently increased the length-width ratio of preserved bar fragments from approximately two and one half to over five. When combined with earlier work on the Skeiðará jökulhlaup bars, and studies of jökulhlaup deposits elsewhere on Skeiðarársandur these observations increase our understanding of the preservation potential and final form of jökulhlaup deposits and provide the basis for an improved model for the recognition of jökulhlaup deposits in the geomorphological and sedimentary record.

  12. Joint impact of rainfall and tidal level on flood risk in a coastal city with a complex river network: a case study of Fuzhou City, China

    Directory of Open Access Journals (Sweden)

    J. J. Lian

    2013-02-01

    Full Text Available Coastal cities are particularly vulnerable to flood under multivariable conditions, such as heavy precipitation, high sea levels, and storms. The combined effect of multiple sources and the joint probability of extremes should be considered to assess and manage flood risk better. This paper aims to study the combined effect of rainfall and the tidal level of the receiving water body on flood probability and severity in Fuzhou City, which has a complex river network. Flood severity under a range of precipitation intensities, with return periods (RPs of 5 yr to 100 yr, and tidal levels was assessed through a hydrodynamic model verified by data observed during Typhoon Longwang in 2005. According to the percentages of the river network where flooding occurred, the threshold conditions for flood severity were estimated in two scenarios: with and without working pumps. In Fuzhou City, working pumps efficiently reduce flood risk from precipitation within a 20-yr RP. However, the pumps may not work efficiently when rainfall exceeds a 100-yr RP because of the limited conveyance capacity of the river network. Joint risk probability was estimated through the optimal copula. The joint probability of rainfall and tidal level both exceeding their threshold values is very low, and the greatest threat in Fuzhou comes from heavy rainfall. However, the tidal level poses an extra risk of flood. Given that this extra risk is ignored in the design of flood defense in Fuzhou, flood frequency and severity may be higher than understood during design.

  13. Central Asia’s Ili River Ecosystem as a Wicked Problem: Unraveling Complex Interrelationships at the Interface of Water, Energy, and Food

    Directory of Open Access Journals (Sweden)

    Steven G. Pueppke

    2018-04-01

    Full Text Available The Ili River originates in the mountains of Xinjiang, China, and flows across an increasingly arid landscape before terminating in Kazakhstan’s Lake Balkhash, which has no outlet to the ocean. The river has been extensively impounded and diverted over the past half century to produce hydroelectric power and food on irrigated land. Water withdrawals are increasing to the extent that they are beginning to threaten the ecosystem, just as it is becoming stressed by altered inflows as glaciers retreat and disappear. If the Ili River ecosystem is to be preserved, it is crucial that we thoroughly understand the spatial and temporal nuances of the interrelationships between water, energy, and food—and the vulnerability of these components to climate change. The ecosystem has all of the characteristics of a classically-defined “wicked problem”, and so it warrants treatment as a complex and dynamic challenge subject to changing assumptions, unexpected consequences, and strong social and economic overtones. Research should thus focus not just on new knowledge about the water, energy, or food component, but on advancing our understanding of the ecosystem as a whole. This will require the participation of interdisciplinary teams of researchers with both tacit and specialized knowledge.

  14. Numerical modelling of river processes: flow and river bed deformation

    NARCIS (Netherlands)

    Tassi, P.A.

    2007-01-01

    The morphology of alluvial river channels is a consequence of complex interaction among a number of constituent physical processes, such as flow, sediment transport and river bed deformation. This is, an alluvial river channel is formed from its own sediment. From time to time, alluvial river

  15. Physical habitat predictors of Manayunkia speciosa distribution in the Klamath River and implications for management of Ceratomyxa shasta, a parasite with a complex life cycle

    Science.gov (United States)

    Jordan, M. S.; Alexander, J. D.; Grant, G. E.; Bartholomew, J. L.

    2011-12-01

    Management strategies for parasites with complex life cycles may target not the parasite itself, but one of the alternate hosts. One approach is to decrease habitat for the alternate host, and in river systems flow manipulations may be employed. Two-dimensional hydraulic models can be powerful tools for predicting the relationship between flow alterations and changes in physical habit, however they require a rigorous definition of physical habitat for the organism of interest. We present habitat characterization data for the case of the alternate host of a salmonid parasite and introduce how it will be used in conjunction with a 2-dimensional hydraulic model. Ceratomyxa shasta is a myxozoan parasite of salmonids that requires a freshwater polychaete Manayunkia speciosa to complete its life cycle. Manayunkia speciosa is a small (3mm) benthic filter-feeding worm that attaches itself perpendicularly to substrate through construction of a flexible tube. In the Klamath River, CA/OR, C. shasta causes significant juvenile salmon mortality, imposing social and economic losses on commercial, sport and tribal fisheries. An interest in manipulating habitat for the polychaete host to decrease the abundance of C. shasta has therefore developed. Unfortunately, there are limited data on the habitat requirements of M. speciosa or the influence of streamflow regime and hydraulics on population dynamics and infection prevalence. This work aims to address these data needs by identifying physical habitat variables that influence the distribution of M. speciosa and determining the relationship between those variables, M. speciosa population density, and C. shasta infection prevalence. Biological samples were collected from nine sites representing three river features (runs, pools, and eddies) within the Klamath River during the summer and fall of 2010 and 2011. Environmental data including depth, velocity, and substrate, were collected at each polychaete sampling location. We tested

  16. Fluvial geomorphology: where do we go from here?

    Science.gov (United States)

    Smith, Derald G.

    1993-07-01

    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. Contrasting the roles of section length and instream habitat enhancement for river restoration success: a field study on 20 European restoration projects

    NARCIS (Netherlands)

    Hering, D.; Aroviita, J.; Baattrup-Pedersen, A.; Brabec, K.; Buijse, T.; Ecke, F.; Friberg, N.; Gielczewski, Marek; Januschke, K.; Köhler, J.; Kupilas, Benjamin; Lorenz, A.W.; Muhar, S.; Paillex, Amael; Poppe, Michaela; Schmidt, T.; Schmutz, S.; Vermaat, J.; Verdonschot, R.C.M.; Verdonschot, P.F.M.; Wolter, Christian; Kail, J.

    2015-01-01

    1. Restoration of river hydromorphology often has limited detected effects on river biota. One frequently discussed reason is that the restored river length is insufficient to allow populations to develop and give the room for geomorphologic processes to occur. 2. We investigated ten pairs of

  18. Coastal geomorphological study of pocket beaches in Crete, with the use of planview indices.

    Science.gov (United States)

    Alexandrakis, George; Karditsa, Aikaterini; Poulos, Serafim; Kampanis, Nikos

    2013-04-01

    The formation of pocket beaches is a result of a large number of processes and mechanisms that vary on space and time scales. This study aims in defining the planform characteristics of pocket beaches in Crete Isl. and to determine their sheltering effect, embaymentization and their status of equilibrium. Thus, data from 30 pocket beaches along the coastline of Crete, with different geomorphological and hydrodynamical setting, were collected. Planform parameters were applied and coastal planview indices from the bibliography were applied. The parameters included: length and orientation of the headlands between the pocket beach; length between the bay entrance and the center of the beach; lengths of the i) embayed shoreline, ii) embayed beach, iii) beach segment located at the shadow of a headland; linear distance and orientation between the edges of the embayed beach; direction of the incident wave energy flux; wave crest obliquity to the control line; beach area, maximum beach width and headland orientation and river/ torrent catchment areas in beach zones that an active river system existed (Bowman et al.2009). For the morphological mapping of the study areas, 1:5000 orthophoto maps were used. Wave regime has been calculated with the use of prognostic equations and utilising local wind data (mean annual frequency of wind speed and direction), provided by the Wind and Wave Atlas of the Eastern Mediterranean Sea. The diffraction and refraction of the waves has been simulated with the use of numerical models. The study shows that Cretan pocket beaches display a wide range of indentation, suggesting that is the result of several parameters that include tectonics, coastal hydrodynamics and river catchment areas. The more indented bays are, the shorter their beaches become, while low-indented pocket beaches are the widest and the longest ones. Beaches with headland with large length appear to be more protected and receive smaller amount of wave energy. Most of the

  19. Controles hidrogeomorfológicos nas unidades vegetacionais da planície aluvial do rio Araguaia, Brasil - DOI: 10.4025/actascibiolsci.v30i4.5871 Hydro-geomorphologic controls in the vegetation of the Araguaia river floodplain, Brazil - DOI: 10.4025/actascibiolsci.v30i4.5871

    Directory of Open Access Journals (Sweden)

    Samia Aquino

    2008-11-01

    of the channel that consume the alluvial plain removed in particular large arboreal vegetation types, and the high rates of sedimentation contribute to the formation of the most recent geomorphologic unit of the plain, which is being colonized especially by herbaceous species.

  20. Application of Geomorphologic Factors for Identifying Soil Loss in Vulnerable Regions of the Cameron Highlands

    Directory of Open Access Journals (Sweden)

    Kahhoong Kok

    2018-03-01

    Full Text Available The main purpose of this study is to propose a methodology for identifying vulnerable regions in the Cameron Highlands that are susceptible to soil loss, based on runoff aggregation structure and the energy expenditure pattern of the natural river basin, within the framework of power law distribution. To this end, three geomorphologic factors, namely shear stress and stream power, as well as the drainage area of every point in the basin of interest, have been extracted using GIS, and then their complementary cumulative distributions are graphically analyzed by fitting them to power law distribution, with the purpose of identifying the sensitive points within the basin that are susceptible to soil loss with respect to scaling regimes of shear stress and stream power. It is observed that the range of vulnerable regions by the scaling regime of shear stress is much narrower than by the scaling regime of stream power. This result seems to suggest that shear stress is a scale-dependent factor, which does not follow power law distribution and does not adequately reflect the energy expenditure pattern of a river basin. Therefore, stream power is preferred as a more reasonable factor for the evaluation of soil loss. The methodology proposed in this study can be validated by visualizing the path of soil loss, which is generated from the hillslope process (characterized by the local slope to the valley through a fluvial process (characterized by the drainage area as well as the local slope.

  1. How temporal patterns in rainfall determine the geomorphology and carbon fluxes of tropical peatlands

    Science.gov (United States)

    Hoyt, Alison M.; Gandois, Laure; Eri, Jangarun; Dommain, René; Abu Salim, Kamariah; Kai, Fuu Ming; Haji Su’ut, Nur Salihah; Harvey, Charles F.

    2017-01-01

    Tropical peatlands now emit hundreds of megatons of carbon dioxide per year because of human disruption of the feedbacks that link peat accumulation and groundwater hydrology. However, no quantitative theory has existed for how patterns of carbon storage and release accompanying growth and subsidence of tropical peatlands are affected by climate and disturbance. Using comprehensive data from a pristine peatland in Brunei Darussalam, we show how rainfall and groundwater flow determine a shape parameter (the Laplacian of the peat surface elevation) that specifies, under a given rainfall regime, the ultimate, stable morphology, and hence carbon storage, of a tropical peatland within a network of rivers or canals. We find that peatlands reach their ultimate shape first at the edges of peat domes where they are bounded by rivers, so that the rate of carbon uptake accompanying their growth is proportional to the area of the still-growing dome interior. We use this model to study how tropical peatland carbon storage and fluxes are controlled by changes in climate, sea level, and drainage networks. We find that fluctuations in net precipitation on timescales from hours to years can reduce long-term peat accumulation. Our mathematical and numerical models can be used to predict long-term effects of changes in temporal rainfall patterns and drainage networks on tropical peatland geomorphology and carbon storage. PMID:28607068

  2. How temporal patterns in rainfall determine the geomorphology and carbon fluxes of tropical peatlands.

    Science.gov (United States)

    Cobb, Alexander R; Hoyt, Alison M; Gandois, Laure; Eri, Jangarun; Dommain, René; Abu Salim, Kamariah; Kai, Fuu Ming; Haji Su'ut, Nur Salihah; Harvey, Charles F

    2017-06-27

    Tropical peatlands now emit hundreds of megatons of carbon dioxide per year because of human disruption of the feedbacks that link peat accumulation and groundwater hydrology. However, no quantitative theory has existed for how patterns of carbon storage and release accompanying growth and subsidence of tropical peatlands are affected by climate and disturbance. Using comprehensive data from a pristine peatland in Brunei Darussalam, we show how rainfall and groundwater flow determine a shape parameter (the Laplacian of the peat surface elevation) that specifies, under a given rainfall regime, the ultimate, stable morphology, and hence carbon storage, of a tropical peatland within a network of rivers or canals. We find that peatlands reach their ultimate shape first at the edges of peat domes where they are bounded by rivers, so that the rate of carbon uptake accompanying their growth is proportional to the area of the still-growing dome interior. We use this model to study how tropical peatland carbon storage and fluxes are controlled by changes in climate, sea level, and drainage networks. We find that fluctuations in net precipitation on timescales from hours to years can reduce long-term peat accumulation. Our mathematical and numerical models can be used to predict long-term effects of changes in temporal rainfall patterns and drainage networks on tropical peatland geomorphology and carbon storage.

  3. The input of geomorphology to oil-related developments in Shetland and Northeast Scotland

    International Nuclear Information System (INIS)

    Ritchie, W.

    1991-01-01

    In essence, the input of coastal geomorphology to most oil-related developments at the coastline has been descriptive environmental classification. The uses to which this information has been put are twofold: (1) as background reconnaissance data that are prepared in advance of a development, such as the exploitation of a nearshore drilling lease or a pipeline landfall, and (2) as a basic element in oil spill contingency mapping. A more specialized use of geomorphology has been environmental management advice relating to the construction, restoration, and operation of large-diameter oil and gas pipeline landfalls - all of which make their approach in Northeast Scotland through beach and dune complexes. The techniques consist of traditional morphological mapping considering form, aspect, materials, energy, and estimations of contemporary processes. Implicit in this mapping is the recognition of vulnerability which, in turn, relates closely to habitat recognition. Time is rarely available for process-type measurements. There is also a dependence on existing maps, aerial photographs, and reports. The survey may be done on foot, from boats, fixed-wing aircraft, or helicopters. Airborne video is increasingly being used as a supplementary means of data acquisition. Vertical airborne video used with an image-processing and G.I.S. system shows great potential and has been used experimentally for pipeline route selection

  4. Developing Connectivist Schemas for Geological and Geomorphological Education

    Science.gov (United States)

    Whalley, B.

    2012-12-01

    Teaching geology is difficult; students need to grasp changes in time over three dimensions. Furthermore, the scales and rates of change in four dimensions may vary over several orders of magnitude. Geological explanations incorporate ideas from physics, chemistry, biology and engineering, lectures and textbooks provide a basic framework but they need to be amplified by laboratories and fieldwork involving active student participation and engagement. Being shown named 'things' is only a start to being able to being able to inculcate geological thinking that requires a wide and focused viewpoints. Kastens and Ishikawa (2006) suggested five aspects of thinking geologically, summarised as: 1. Observing, describing, recording, communicating geologically entities (ie basic cognitive skills) 2. (mentally) manipulating these entities 3. interpreting them via causal relationships 4. predicting other aspects using the basic knowledge (to create new knowledge) 5. using cognitive strategies to develop new ways of interpreting gained knowledge. These steps can be used follow the sequence from 'known' through 'need to know' to using knowledge to gain better geologic explanation, taken as enquiry-based or problem solving modes of education. These follow ideas from Dewey though Sternberg's 'thinking styles' and Siemens' connectivist approaches. Implementation of this basic schema needs to be structured for students in a complex geological world in line with Edelson's (2006) 'learning for' framework. In a geomorphological setting, this has been done by showing students how to interpret a landscape (landform, section etc) practice their skills and thus gain confidence with a tutor at hand. A web-based device, 'Virtorial' provides scenarios for students to practice interpretation (or even be assessed with). A cognitive tool is provided for landscape interpretation by division into the recognition of 'Materials' (rock, sediments etc), Processes (slope, glacial processes etc) and

  5. Morphological changes and hydrodynamic effects of the urbanization process of river Tamanduateí watershed – Metropolitan area of São Paulo

    Directory of Open Access Journals (Sweden)

    Isabel Cristina Moroz-Caccia Gouveia

    2017-08-01

    Full Text Available Relying on Anthropogenic and Historical Geomorphology, this paper presents methodology applied to the River Tamanduateí watershed for qualitative and quantitative analysis of changes resulting from the urbanization process in physical systems, from the geomorphological cartography. The approach has as its main premise consider the human actions into the landscape as geomorphological nature of actions whose effects can be measured using indicators and benchmarks. Among other analysis, the identification of the original or pre-urban characteristics and anthropogenic changes allowed us to estimate the loss of the water storage capacity due to the suppression of river plains and changes in hydrodynamic balance in the areas of hydrographic basin.

  6. Alligator Rivers Regions Research Institute research report 1983-84

    International Nuclear Information System (INIS)

    1984-01-01

    The Institute undertakes and coordinates research required to ensure the protection of the environment in the Alligator Rivers Region from any consequences resulting from the mining and processing of uranium ore. Research projects outlined are in aquatic biology, terrestrial ecology, analytical chemistry, environmental radioactivity and geomorphology

  7. Hyporheic exchange in mountain rivers I: Mechanics and environmental effects

    Science.gov (United States)

    Daniele Tonina; John M. Buffington

    2009-01-01

    Hyporheic exchange is the mixing of surface and shallow subsurface water through porous sediment surrounding a river and is driven by spatial and temporal variations in channel characteristics (streambed pressure, bed mobility, alluvial volume and hydraulic conductivity). The significance of hyporheic exchange in linking fluvial geomorphology, groundwater, and riverine...

  8. Exploring the Geomorphology of the Amazon's Planalto and Understanding the Origin of the Modern Amazon Basin with Imaging Radar:

    Science.gov (United States)

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

    2015-12-01

    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

  9. Reconstructing the paleo-topography and paleo-environmental features of the Sarno River plain (Italy) before the AD 79 eruption of Somma-Vesuvius volcanic complex

    Science.gov (United States)

    Vogel, Sebastian; Märker, Michael

    2010-05-01

    SSP1.4 Understanding mixed siliciclastic-volcaniclastic depositional systems and their relationships with geodynamics or GD2.3/CL4.14/GM5.8/MPRG22/SSP3.5 Reconstruction of ancient continents: Dating and characterization of paleosurfaces Reconstructing the paleo-topography and paleo-environmental features of the Sarno River plain (Italy) before the AD 79 eruption of Somma-Vesuvius volcanic complex Sebastian Vogel[1] & Michael Märker[1] [1] Heidelberg Academy of Sciences and Humanities c/o University of Tübingen, Rümelinstraße 19-23, D-72070 Tübingen, Germany. Within the geoarchaeological research project "Reconstruction of the Ancient Cultural Landscape of the Sarno River Plain" undertaken by the German Archaeological Institute in cooperation with the Heidelberg Academy of Sciences and Humanities/University of Tübingen a methodology was developed to model the spatial dispersion of volcanic deposits of Somma-Vesuvius volcanic complex since its Plinian eruption AD 79. Eventually, this was done to reconstruct the paleo-topography and paleo-environment of the Sarno River plain before the eruption AD 79. We collected, localized and digitized more than 1,800 core drillings to gain a representative network of stratigraphical information covering the entire plain. Besides other stratigraphical data including the characteristics of the pre-AD 79 stratum, the depth to the pre-AD 79 paleo-surface was identified from the available drilling documentation. Instead of applying a simple interpolation of the drilling data, we reconstructed the pre-AD 79 paleo-surface with a sophisticated geostatistical methodology using a machine based learning approach based on classification and regression trees. We hypothesize that the present-day topography reflects the ancient topography, because the eruption of AD 79 coated the ancient topography, leaving ancient physiographic elements of the Sarno River plain still recognizable in the present-day topography. Therefore, a high resolution

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

    Directory of Open Access Journals (Sweden)

    P. Brandolini

    2006-01-01

    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.

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

    Science.gov (United States)

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

    2006-06-01

    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.

  12. The contribution of geomorphological research to environmental issues in Mexico

    Directory of Open Access Journals (Sweden)

    Gerardo Bocco

    2013-07-01

    Full Text Available The paper analyzes the development of Mexican geomorphology and specially its contribution to environmental issues. To this end, a thorough literature review was carried out; papers were differentiated according to the type of journal (Mexican and international. Special emphasis was placed on analyzing whether the interest on environment was derived from a well defined theoretical framework, in particular in terms of the insertion of geomorphology in the geographic arena in Mexico. The review has focused on secientific papers duly refereed and available at the Internet. Thus other research was not included. However, that the database described in this paper represents a solid sample of the entire universe of the efforts of Mexican geomorphologists.

  13. SOILS VULNERABILITY OF CATCHMENT ALMAŞ AT GEOMORPHOLOGIC CONTEMPORARY PROCESSES

    Directory of Open Access Journals (Sweden)

    MĂDĂLINA-IOANA RUS

    2015-03-01

    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.

  14. Geomorphology from space: A global overview of regional landforms

    Science.gov (United States)

    Short, Nicholas M. (Editor); Blair, Robert W., Jr. (Editor)

    1986-01-01

    This book, Geomorphology from Space: A Global Overview of Regional Landforms, was published by NASA STIF as a successor to the two earlier works on the same subject: Mission to Earth: LANDSAT views the Earth, and ERTS-1: A New Window on Our Planet. The purpose of the book is threefold: first, to serve as a stimulant in rekindling interest in descriptive geomorphology and landforms analysis at the regional scale; second, to introduce the community of geologists, geographers, and others who analyze the Earth's surficial forms to the practical value of space-acquired remotely sensed data in carrying out their research and applications; and third, to foster more scientific collaboration between geomorphologists who are studying the Earth's landforms and astrogeologists who analyze landforms on other planets and moons in the solar system, thereby strengthening the growing field of comparative planetology.

  15. On the LiDAR contribution for the archaeological and geomorphological study of a deserted medieval village in Southern Italy

    International Nuclear Information System (INIS)

    Lasaponara, Rosa; Coluzzi, Rosa; Gizzi, Fabrizio T; Masini, Nicola

    2010-01-01

    Airborne laser scanning (ALS) is an optical measurement technique for obtaining high-precision information about the Earth's surface including basic terrain mapping (digital terrain model, bathymetry, corridor mapping), vegetation cover (forest assessment and inventory) and coastal and urban areas. Recent studies examined the possibility of using ALS in archaeological investigations to identify earthworks, although the ability of ALS measurements in this context has not yet been studied in detail. This paper focuses on the potential of the latest generation of airborne ALS for the detection and the spatial characterization of micro-topographic relief linked to archaeological and geomorphological features. The investigations were carried out near Monteserico, an archaeological area in the Basilicata region (Southern Italy) which is characterized by complex topographical and morphological features. The study emphasizes that the DTM-LiDAR data are a powerful instrument for detecting surface discontinuities relevant for investigating geomorphological processes and cultural features. The LiDAR survey allowed us to identify the urban shape of a medieval village, by capturing the small differences in height produced by surface and shallow archaeological remains (the so-called shadow marks) which were not visible from ground or from optical dataset. In this way, surface reliefs and small elevation changes, linked to geomorphological and archaeological features, have been surveyed with great detail

  16. Unravelling recent environmental change in a lowland river valley, eastern Ireland: geoarchaeological applications

    Science.gov (United States)

    Foster, Gez; Turner, Jonathan

    2010-05-01

    This paper reports the preliminary findings of an Irish Heritage Council INSTAR funded research project on the geoarchaeology and fluvial geomorphology of the lower River Boyne valley, eastern Ireland. The nature and evolution of the contemporary Boyne floodplain at Dunmoe, Co. Meath (53° 40' 22.8" N, 6° 37' 54.7" W) has been investigated using a multi-technique approach combining field and terrestrial LiDAR-based geomorphological mapping, radiocarbon dating of channel migration activity, electrical resistivity tomography surveys of sub-surface topography and high-resolution X-ray and XRF geochemical characterisation of fine-grained sediment fill sequences. All of these lines of evidence support a tripartite sub-division of the floodplain. Valley marginal floodplain Zone 1 is characterised by a colluvial sediment fill which has buried an irregular ditch-basin-platform surface containing recent archaeological material. Subtle variations in mapped elevation suggest that the buried surface may represent the site of an abandoned river-side complex, possibly a small docking area or port. Geomorphological field relationships suggest that the possible archaeological site was connected to a former bank line position of the main River Boyne (floodplain Zone 2) via a small canal. Radiocarbon dating of Zone 2 channel gravels suggests that the channel associated with this bank position was abandoned some time before 1490-1610 AD. Subsequent vertical and lateral channel migration, the onset of which has been radiocarbon dated to the 17th or 18th century AD, led to the development of the lowest and most recent floodplain surface (Zone 3). The sedimentology and geochemistry of the Zone 2 and 3 fluvial sediment sequences suggests that recent centuries have involved an increase in fluvial flood risk, evidenced by the burial of alluvial soils by bedded, shell-rich sands. A more complete understanding of the timing and environmental drivers of increasing flood risk is anticipated

  17. On the relation between fluvio-deltaic flood basin geomorphology and the wide-spread occurrence of arsenic pollution in shallow aquifers.

    Science.gov (United States)

    Donselaar, Marinus E; Bhatt, Ajay G; Ghosh, Ashok K

    2017-01-01

    Pollution of groundwater with natural (geogenic) arsenic occurs on an enormous, world-wide scale, and causes wide-spread, serious health risks for an estimated more than hundred million people who depend on the use of shallow aquifers for drinking and irrigation water. A literature review of key studies on arsenic concentration levels yields that Holocene fluvial and deltaic flood basins are the hotspots of arsenic pollution, and that the dominant geomorphological setting of the arsenic-polluted areas consists of shallow-depth meandering-river deposits with sand-prone fluvial point-bar deposits surrounded by clay-filled (clay plug) abandoned meander bends (oxbow lakes). Analysis of the lithofacies distribution and related permeability contrasts of the geomorphological elements in two cored wells in a point bar and adjacent clay plug along the Ganges River, in combination with data of arsenic concentrations and organic matter content reveals that the low-permeable clay-plug deposits have a high organic matter content and the adjacent permeable point-bar sands show high but spatially very variable arsenic concentrations. On the basis of the geomorphological juxtaposition, the analysis of fluvial depositional processes and lithofacies characteristics, inherent permeability distribution and the omnipresence of the two geomorphological elements in Holocene flood basins around the world, a generic model is presented for the wide-spread arsenic occurrence. The anoxic deeper part (hypolimnion) of the oxbow lake, and the clay plugs are identified as the loci of reactive organic carbon and microbial respiration in an anoxic environment that triggers the reductive dissolution of iron oxy-hydroxides and the release of arsenic on the scale of entire fluvial floodplains and deltaic basins. The adjacent permeable point-bar sands are identified as the effective trap for the dissolved arsenic, and the internal permeability heterogeneity is the cause for aquifer compartmentalization

  18. Predicting multi-scale relationships between geomorphology and bedrock geology of the rocky intertidal in Central and Northern California

    Science.gov (United States)

    Wheeler, A.; Aiello, I. W.

    2014-12-01

    Substratum geology is fundamental in shaping rocky shore morphology. Specific lithologies have various responses to wave action, tectonic features (e.g. fractures, faults) and sedimentary structures (e.g. bedding), creating distinctive weathering profiles. Along with local oceanography and climate forcing, different rock substrata create coastal morphologies that can vary distinctly between scales, ranging from mm to km. Despite the complexity of the system, qualitative observations show coastal areas with similar rock types share similar geomorphologies. Thus, a statistic relationship between geomorphology (expressed for instance by surface parameter rugosity) and geology can be envisaged. There are multiple benefits of finding such a relationship, as rocky intertidal geomorphology can be an important determinant in which organisms can settle, grow, and survive in near shore communities: allowing the prediction of geomorphologic parameters determining coastal ecology solely based on substratum geology, a crucial aspect in guiding the selection of marine protected areas. This study presents preliminary results of multi-scale geospatial surveys (cm to tens of meters) of rocky intertidal outcrops from Central to Northern California using a Terrestrial Laser Scanner. The outcrops investigated are representative of the most common igneous and sedimentary rocks in California (granitoids, conglomerates, sandstones, mudstones) and metamorphic units. The statistical analysis of the survey data support the hypothesis that surface properties can change significantly with changing scale, each rock type having distinct surface characteristics which are similar to comparable lithologies exposed at different locations. These scale dependent variations are controlled by different lithologic and structural characteristics of the outcrop in question. Our data also suggests lithologic variability within a rock unit could be a very significant factor in controlling changes in

  19. Feedback of Erosional-Depositional Processes Generating Anabranching Patterns in a Mega-River the Case of the PARANÁ River, Argentina

    Science.gov (United States)

    Latrubesse, E. M.; Pereira, M.; Ramonell, C. G.; Szupiany, R. N.

    2011-12-01

    A new category of "very large" rivers was recently proposed and defined as mega-rivers, which are those rivers with a Qmean of more than ~17,000m3/s. This category includes the nine largest rivers on Earth and the Parana River is one of the selected members of that peculiar group. The planform adjustment of mega-rivers is a variety of anabranching patterns characterized by the existence of alluvial islands. The processes and mechanisms involved in the generation of the different anabranching styles, however, are not well understood. The Paraná channel pattern has been classified as a low to moderate anabranching, low sinuosity with tendency to braided and having a meandering thalweg. We analyzed a reach of the middle Paraná in Argentina applying a combined multitemporal, hydraulic, sedimentologic and geomorphologic approach. Multitemporal geomorphologic maps, sedimentary descriptions of bars, islands and banks, volumetric calculations using multitemporal bathymetric charts, measurements with ADCP and bathymetric surveys with echosound, sediment transport estimations and the hydrological analysis of available data from gauge stations were some of the tools used in our research. The evolution of the reach was studied from 1908 to present. The reach is subdivided in two sub-reaches (named Chapeton and Curtiembre) which are comprised between nodal points. Chapeton has been in a more mature quasi-equilibrium state through the XX Century but the main channel in Curtiembre evolved from a single pattern to anabranching pattern since 1950s. We conclude that the generation of the anabranching pattern in the studied reach depends of a combination of factors such as the architecture of the floodplain and islands, the main role played by the morphodynamics and shifting of the thalweg, the availability and path of sandy sediments bedforms architecture and the temporal variability of the effective discharge among other secondary factors. A feedback system coupling erosional

  20. The problem of scale in planetary geomorphology

    Science.gov (United States)

    Rossbacher, L. A.

    1985-01-01

    Recent planetary exploration has shown that specific landforms exhibit a significant range in size between planets. Similar features on Earth and Mars offer some of the best examples of this scale difference. The difference in heights of volcanic features between the two planets has been cited often; the Martian volcano Olympus Mons stands approximately 26 km high, but Mauna Loa rises only 11 km above the Pacific Ocean floor. Polygonally fractured ground in the northern plains of Mars has diameters up to 20 km across; the largest terrestrial polygons are only 500 m in diameter. Mars also has landslides, aeolian features, and apparent rift valleys larger than any known on Earth. No single factor can explain the variations in landform size between planets. Controls on variation on Earth, related to climate, lithology, or elevation, have seldom been considered in detail. The size differences between features on Earth and other planets seem to be caused by a complex group of interacting relationships. The major planetary parameters that may affect landform size are discussed.

  1. Directions in Geoheritage Studies: Suggestions from the Italian Geomorphological Community

    Science.gov (United States)

    Panizza, Valeria

    2015-04-01

    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

  2. Surface complexation modeling for predicting solid phase arsenic concentrations in the sediments of the Mississippi River Valley alluvial aquifer, Arkansas, USA

    Science.gov (United States)

    Sharif, M.S.U.; Davis, R.K.; Steele, K.F.; Kim, B.; Hays, P.D.; Kresse, T.M.; Fazio, J.A.

    2011-01-01

    The potential health impact of As in drinking water supply systems in the Mississippi River Valley alluvial aquifer in the state of Arkansas, USA is significant. In this context it is important to understand the occurrence, distribution and mobilization of As in the Mississippi River Valley alluvial aquifer. Application of surface complexation models (SCMs) to predict the sorption behavior of As and hydrous Fe oxides (HFO) in the laboratory has increased in the last decade. However, the application of SCMs to predict the sorption of As in natural sediments has not often been reported, and such applications are greatly constrained by the lack of site-specific model parameters. Attempts have been made to use SCMs considering a component additivity (CA) approach which accounts for relative abundances of pure phases in natural sediments, followed by the addition of SCM parameters individually for each phase. Although few reliable and internally consistent sorption databases related to HFO exist, the use of SCMs using laboratory-derived sorption databases to predict the mobility of As in natural sediments has increased. This study is an attempt to evaluate the ability of the SCMs using the geochemical code PHREEQC to predict solid phase As in the sediments of the Mississippi River Valley alluvial aquifer in Arkansas. The SCM option of the double-layer model (DLM) was simulated using ferrihydrite and goethite as sorbents quantified from chemical extractions, calculated surface-site densities, published surface properties, and published laboratory-derived sorption constants for the sorbents. The model results are satisfactory for shallow wells (10.6. m below ground surface), where the redox condition is relatively oxic or mildly suboxic. However, for the deep alluvial aquifer (21-36.6. m below ground surface) where the redox condition is suboxic to anoxic, the model results are unsatisfactory. ?? 2011 Elsevier Ltd.

  3. Unraveling the Quaternary river incision in the Moselle valley (Rhenish Massif, Germany): new insights from cosmogenic nuclide dating (10Be/26Al) of the Main Terrace complex

    Science.gov (United States)

    Rixhon, Gilles; Cordier, Stéphane; Harmand, Dominique; May, Simon Matthias; Kelterbaum, Daniel; Dunai, Tibor; Binnie, Steven; Brückner, Helmut

    2014-05-01

    Throughout the whole river network of the Rhenish Massif, the terrace complex of the so-called Main Terrace forms the morphological transition between a wide upper palaeovalley (plateau valley) and a deeply incised lower valley. The youngest level of this Main Terrace complex (YMT), directly located at the edge of the incised valley, represents a dominant geomorphic feature in the terrace flight; it is often used as a reference level to identify the start of the main middle Pleistocene incision episode (Demoulin & Hallot, 2009). The latter probably reflects the major tectonic pulse that affected the whole Massif and was related to an acceleration of the uplift rates (Demoulin & Hallot, 2009). The Main terraces are particularly well preserved in the lower Moselle valley and are characterized by a constant absolute elevation of their base along a 150 km-long reach. Despite that various hypotheses have been proposed to explain this horizontality (updoming, faulting...), all studies assumed an age of ca. 800 ka for the YMT, mainly based on the questionable extrapolation of palaeomagnetic data obtained in the Rhine valley. Therefore, a reliable chronological framework is still required to unravel the spatio-temporal characteristics of the Pleistocene evolution of the Moselle valley. In this study, we apply cosmogenic nuclide dating (10Be/26Al) to fluvial sediments pertaining to the Main Terrace complex or to the upper Middle Terraces. Several sites along the lower Moselle were sampled following two distinct sampling strategies: (i) depth profiles where the original terrace (palaeo-)surface is well preserved and did not experience much postdepositional burial (e.g., loess cover); and (ii) the isochron technique where the sediment thickness exceeds 3 m. Cosmogenic nuclide ages recently obtained for three rivers in the Meuse catchment in the western Rhenish Massif demonstrated that the Main Terraces were younger than expected and their abandonment was diachronic along the

  4. The "Geomorphologic Diagonal" of Central Europe - towards a new morphotectonic interpretation of macroforms in average mountains

    Science.gov (United States)

    Zoeller, Ludwig

    2016-04-01

    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

  5. Preface to the volume Large Rivers

    Science.gov (United States)

    Latrubesse, Edgardo M.; Abad, Jorge D.

    2018-02-01

    The study and knowledge of the geomorphology of large rivers increased significantly during the last years and the factors that triggered these advances are multiple. On one hand, modern technologies became more accessible and their disseminated usage allowed the collection of data from large rivers as never seen before. The generalized use of high tech data collection with geophysics equipment such as acoustic Doppler current profilers-ADCPs, multibeam echosounders, plus the availability of geospatial and computational tools for morphodynamics, hydrological and hydrosedimentological modeling, have accelerated the scientific production on the geomorphology of large rivers at a global scale. Despite the advances, there is yet a lot of work ahead. Good parts of the large rivers are in the tropics and many are still unexplored. The tropics also hold crucial fluvial basins that concentrate good part of the gross domestic product of large countries like the Parana River in Argentina and Brazil, the Ganges-Brahmaputra in India, the Indus River in Pakistan, and the Mekong River in several countries of South East Asia. The environmental importance of tropical rivers is also outstanding. They hold the highest biodiversity of fluvial fauna and alluvial vegetation and many of them, particularly those in Southeast Asia, are among the most hazardous systems for floods in the entire world. Tropical rivers draining mountain chains such as the Himalaya, the Andes and insular Southeast Asia are also among the most heavily sediment loaded rivers and play a key role in both the storage of sediment at continental scale and the transference of sediments from the continent to the Ocean at planetary scale (Andermann et al., 2012; Latrubesse and Restrepo, 2014; Milliman and Syvitski, 1992; Milliman and Farsnworth, 2011; Sinha and Friend, 1994).

  6. Geomorphological evolution of badlands based on the dynamics of ...

    Indian Academy of Sciences (India)

    In the light of the evidences, a modified schematic geomorphic evolution of badlands ... Chambal River follows an anti-formal up-warp. Agarwal et al. (2002) ..... Aging of sediments from .... Makaske B 2001 Anastomosing rivers: A review of their.

  7. SOME GEOMORPHOLOGICAL AND GEOECOLOGICAL IMPACTS OF THE 2010 EXTREME RAINFALLS IN HUNGARY

    Directory of Open Access Journals (Sweden)

    DÉNES LÓCZY

    2012-03-01

    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

  8. Hydrostratigraphy of the Snake River Plain aquifer beneath the Radioactive Waste Management Complex at the Idaho National Engineering Laboratory: A preliminary report

    International Nuclear Information System (INIS)

    Hegmann, M.J.; Wood, S.H.

    1994-01-01

    Geophysical logs for 6 wells which penetrate the Snake River Plain aquifer at the Radioactive Waste Management Complex (RWMC) were analyzed for preliminary information on the hydrostratigraphy. Using stratigraphic correlation of flow groups worked out by Anderson and Lewis (1989), and by Anderson, as well as gamma signatures of flows within these flow groups, correlation of individual flows is attempted. Within these flows, probable permeable zones, suggested by density and caliper logs, are identified, and zones of hydraulic connection are tentatively correlated. In order to understand the response of density and neutron logs in basalt, the geological characteristics are quantified for the 150-ft section of the well C1A core, from depth 550 to 710 ft. 9 refs., 4 figs

  9. Surface complexation modeling of groundwater arsenic mobility: Results of a forced gradient experiment in a Red River flood plain aquifer, Vietnam

    DEFF Research Database (Denmark)

    Jessen, Søren; Postma, Dieke; Larsen, Flemming

    2012-01-01

    , suggesting a comparable As(III) affinity of Holocene and Pleistocene aquifer sediments. A forced gradient field experiment was conducted in a bank aquifer adjacent to a tributary channel to the Red River, and the passage in the aquifer of mixed groundwater containing up to 74% channel water was observed......Three surface complexation models (SCMs) developed for, respectively, ferrihydrite, goethite and sorption data for a Pleistocene oxidized aquifer sediment from Bangladesh were used to explore the effect of multicomponent adsorption processes on As mobility in a reduced Holocene floodplain aquifer......(III) while PO43− and Fe(II) form the predominant surface species. The SCM for Pleistocene aquifer sediment resembles most the goethite SCM but shows more Si sorption. Compiled As(III) adsorption data for Holocene sediment was also well described by the SCM determined for Pleistocene aquifer sediment...

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

    Directory of Open Access Journals (Sweden)

    Menković Ljubomir

    2011-01-01

    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.

  11. River restoration: separating myths from reality

    Science.gov (United States)

    Friberg, N.; Woodward, G.

    2015-12-01

    River restorations are a social construct where degraded systems are physically modified to obtain a pre-disturbance set of attributes. These can be purely esthetic but are often linked to some kind of biotic recovery or the provision of important ecosystem services such as flood control or self-purification. The social setting of restoration projects, with a range of potential conflicts, significantly reduces scale of most interventions to a size with little room, or wish, for natural processes. We show that projects sizes are still very small and that the restoration target is not to recover natural geomorphic processes but rather to fulfil human perception of what a nice stream looks like. One case from Danish lowland streams, using a space-for-time substitution approach, shows excess use of pebble and gravel when restoring channelized sandy bottom streams, de-coupling the link between energy and substrate characteristics that are found in natural lowland systems. This has implication for both the biological structure and functioning of these systems as a direct link between substrate heterogeneity and macroinvertebrate diversity was not found in restored streams, while the density of grazer increased indicating an increased use of periphyton as a basal resource. Another case of adding woody debris to UK lowland streams, using a BACI study design, showed very little effect on the macroinvertebrate community even after a 100-year flood, which indicate that added tree trunks did not provide additional flow refugia. We suggest that restoration schemes should aim at restoring the natural physical structural complexity in the streams and at the same time enhance the possibility of re-generating the natural geomorphological processes sustaining the habitats in streams and rivers.

  12. Naturalness and Place in River Rehabilitation

    Directory of Open Access Journals (Sweden)

    Kirstie Fryirs

    2009-06-01

    Full Text Available An authentic approach to river rehabilitation emphasizes concerns for the natural values of a given place. As landscape considerations fashion the physical template upon which biotic associations take place, various geomorphic issues must be addressed in framing rehabilitation activities that strive to improve river health. An open-ended approach to river classification promotes applications that appreciate the values of a given river, rather than pigeonholing reality. As the geomorphic structure of some rivers is naturally simple, promoting heterogeneity as a basis for management may not always be appropriate. Efforts to protect unique attributes of river systems must be balanced with procedures that look after common features. Concerns for ecosystem functionality must relate to the behavioral regime of a given river, remembering that some rivers are inherently sensitive to disturbance. Responses to human disturbance must be viewed in relation to natural variability, recognizing how spatial relationships in a catchment, and responses to past disturbances, fashion the operation of contemporary fluxes. These fluxes, in turn, influence what is achievable in the rehabilitation of a given reach. Given the inherently adjusting and evolutionary nature of river systems, notional endpoints do not provide an appropriate basis upon which to promote concepts of naturalness and place in the rehabilitation process. These themes are drawn together to promote rehabilitation practices that relate to the natural values of each river system, in preference to applications of "cookbook" measures that build upon textbook geomorphology.

  13. Catchment controls and human disturbances on the geomorphology of small Mediterranean estuarine systems

    Science.gov (United States)

    Estrany, Joan; Grimalt, Miquel

    2014-10-01

    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

  14. Eco-geomorphological Response of an Estuarine Wetland to Changes in the Hydraulic Regime

    Science.gov (United States)

    Howe, A.; Rodrí Guez, J.

    2006-12-01

    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

  15. How to find the sedimentary archive of fluvial pollution in a bedrock-confined river reach

    Science.gov (United States)

    Elznicova, Jitka; Matys Grygar, Tomas; Kiss, Timea; Lelkova, Tereza; Balogh, Marton; Sikora, Martin

    2016-04-01

    The Ohre River springs in the Eastern Germany and it is a tributary of the Labe (Elbe) River in Northwest Bohemia. The river received pollution from several sources during the last five centuries. Most of the pollution sources located along the upper and middle reaches, where the depositional and erosional pattern of the river is highly variable. The upper part of the catchment consists of mainly felsic rocks and the river has a broad floodplain. The middle reach and its right-bank tributaries are deeply incised into the Doupovske Hory Mts., which consists of mafic volcanic rocks; whereas the left-bank tributaries are incised into intrusive and metamorphic rocks of the Krusne Hory Mts. (Ore mountains) with several local ore mines (Ag, Pb and U) in particular in around Olovi and Jachymov. Due to the geologic and geomorphologic complexity, deposition of historical sediments in the middle reach has been spatially limited and uneven, and anomalous background concentrations of risk elements are expected. As a consequence, in the middle reach of the Ohre River it is difficult to find a useful sedimentary archive of historical pollution, though it is desired for two main reasons: (1) to decipher the undocumented and poorly described pollution history from the Krusne Hory Mts. and (2) to better understand the retention of pollutants in the transport zones of a confined river system. Based on historical maps we identified a side-bar (35x320 m) in the middle reach of the river near Straz on Ohre and aimed to describe its formation, its recent erosion/deposition history and to evaluate its sedimentary archive value. In the first half of the 19th century it was an island separated from the valley edge by a side channel. Since then there has been no apparent lateral accretion of the bar (its shape has not been changed), but the upstream part of the side channel aggraded by a sediment plug. We evaluated the current bar topography and geomorphology by a detailed field survey

  16. Enhancing flood hazard estimation methods on alluvial fans using an integrated hydraulic, geological and geomorphological approach

    Science.gov (United States)

    Mollaei, Zeinab; Davary, Kamran; Majid Hasheminia, Seyed; Faridhosseini, Alireza; Pourmohamad, Yavar

    2018-04-01

    Due to the uncertainty concerning the location of flow paths on active alluvial fans, alluvial fan floods could be more dangerous than riverine floods. The United States Federal Emergency Management Agency (FEMA) used a simple stochastic model named FAN for this purpose, which has been practiced for many years. In the last decade, this model has been criticized as a consequence of development of more complex computer models. This study was conducted on three alluvial fans located in northeast and southeast Iran using a combination of the FAN model, the hydraulic portion of the FLO-2D model, and geomorphological information. Initial stages included three steps: (a) identifying the alluvial fans' landforms, (b) determining the active and inactive areas of alluvial fans, and (c) delineating 100-year flood within these selected areas. This information was used as an input in the mentioned three approaches of the (i) FLO-2D model, (ii) geomorphological method, and (iii) FAN model. Thereafter, the results of each model were obtained and geographical information system (GIS) layers were created and overlaid. Afterwards, using a scoring system, the results were evaluated and compared. The goal of this research was to introduce a simple but effective solution to estimate the flood hazards. It was concluded that the integrated method proposed in this study is superior at projecting alluvial fan flood hazards with minimum required input data, simplicity, and affordability, which are considered the primary goals of such comprehensive studies. These advantages are more highlighted in underdeveloped and developing countries, which may well lack detailed data and financially cannot support such costly projects. Furthermore, such a highly cost-effective method could be greatly advantageous and pragmatic for developed countries.

  17. Bathymetry & Geomorphology - A New Seafloor Mapping of the Israeli Exclusive Economic Zone

    Science.gov (United States)

    Tibor, G.; Hall, J. K.; Kanari, M.; Sade, R. A.; Sade, H.; Amit, G.; Gur-Arie, L.; Ketter, T.

    2017-12-01

    Recent extensive activities of oil and gas exploration and production companies in the Israeli Exclusive Economic Zone (EEZ) raised the need for an up-to-date baseline mapping of the seafloor to assist policy makers. The baseline mapping focused on bathymetry, geomorphology, geology, biodiversity, infauna and habitat in order to compile a sensitivity map for the Petroleum Commissioner in the Ministry of Energy in the bid for opening the sea to new natural gas and oil explorations. The Israeli EEZ covers an area of 25,950 sq. km. and reaches a maximum water depth of 2,100 m. It is located within the Levantine Basin, a zone of compression and strike-slip tectonics as Africa pushes into Eurasia. These forces operate on a half kilometer thick of Messinian evaporates and over a dozen kilometers of Pliocene and Pleistocene sediments to produce a complex seafloor morphology. The margin is cut by numerous slumps and canyons, while the basin is traversed by deep sea channels emptying into the moat around Eratosthenes Seamount farther north. The bathymetric and geomorphological mapping was done in three phases using Kongsberg and Elac multibeam sonars installed on different research vessels. The last phase (Aug.-Sept., 2016) covering depths from 1,400 to 2,100 m used the Kongsberg EM302 sonar installed on our new governmental research vessel Bat Galim. It has "state of the art" capabilities to map, sample and analyze the water column, seafloor and sub-bottom from water depths of 10m to 7,000 m. These mapping capabilities are unique in our region, the Eastern Mediterranean and the Red Sea, so we hope to promote research collaborations with our neighbors.

  18. Spatial discontinuity and temporal evolution of channel morphology along a mixed bedrock-alluvial river, upper Drôme River, southeast France: Contingent responses to external and internal controls

    Science.gov (United States)

    Toone, J.; Rice, S. P.; Piégay, H.

    2014-01-01

    The rehabilitation of degraded river channels is often guided by assumptions of continuity, yet in response to spatial and temporal variations in controlling conditions rivers typically display discontinuous response in space and time. This study examines the development of a 5 km reach of the Drôme River, S.E. France, characterised by alternating alluvial and bedrock zones that are separated by abrupt downstream transitions. This reach is representative of the Drôme River as a whole, and other rivers in the European Alps where braided channel planforms have been replaced by more complex, discontinuous morphologies. The primary aims are to understand how this spatial complexity has developed on the Drôme; evaluate how temporal channel changes have been affected by local factors, particularly bedrock exposures, and by long-term, catchment-scale changes in sediment supply and the flood activity; and consider the implications of this discontinuous geomorphology for reach management. The development of geomorphological zonation is examined by documenting sequential changes in channel planform between seven periods, using aerial photography (1948-2006) and by analysing change in bed elevation from profiles surveyed in 1928, 2003 and 2005. Between 1948 and 2001 bedrock exposed in the channel bed and along the floodplain margins defined discontinuities in sediment connectivity that were largely responsible for the configuration of channel zones. The impact of floods on this system was not proportional to flood magnitude. A modest flood in 1978 was an important event that, by incision and avulsion at key locations, defined a pattern of zonation that persisted until the end of the study in 2006. During the final 5 years of the study, alluvial zones that previously responded to large floods by widening underwent narrowing, despite the occurrence of a large flood, and led to an overall reduction in width variance. This resulted from progressive incision beneath and

  19. Water Resources And Geomorphologic Characteristics Of Tushka Area, West Of Lake Nasser, Egypt

    International Nuclear Information System (INIS)

    Elewa, H.H.

    2003-01-01

    The main geomorphologic and drainage characteristics of the Tushka area were delineated through the interpretation of Landsat TM image. The study area displays physiographic features indicative of previous wet climatic conditions. The Nubia aquifer system in the region has a wide extension in the study area and rests un conformably on the Precambrian rocks. The River Nile has its own bearing on the hydrogeological regime of the Tushka and neighbouring areas of Lake Nasser. Comparison of the available data concerning the water levels of Lake Nasser above its submerged bottom (which involves elevations ranging from 50 to 90 m. (a. s. 1.) according to the recorded data between 1964 and 1996), with the static water levels of the groundwater wells reaching the deeper horizons of the Nubia Sandstone aquifer system in the Tushka basin area, suggests that the River Nile acts mostly as an influent stream. However, in some cases, when the static water levels of some deep water-bearing horizons reaches levels above those of the bottom of the lake, water flows from the groundwater reservoirs towards the river which acts as an effluent stream. Other wells have low static water levels compared to those of the bottom of the lake, and the waters of the River Nile most probably recharge the groundwater of these deeper water-bearing horizons of the Nubian aquifer. The prepared equi potentiometric contour map confirms this conclusion as it indicates that the maximum potentiometric level is attained in the north western part of Lake Nasser (at contour 80, near Well No. 12) whereas the minimum potentiometric level is encountered in a small area around Well No. 6 (at contour 50). Hence, the groundwater flow is generally towards Lake Nasser. However, in some instances, it is also moving in an adverse direction. The hydrogeological condition of the study area was conducted based on the variation in lithology, areal extent, recharge and productivity. The study revealed that the Nubia

  20. High-Resolution Characterization of Intertidal Geomorphology by TLS

    Science.gov (United States)

    Guarnieri, A.; Vettore, A.; Marani, M.

    2007-12-01

    Observational fluvial geomorphology has greatly benefited in the last decades from the wide availability of digital terrain data obtained by orthophotos and by means of accurate airborne laser scanner data (LiDAR). On the contrary, the spatially-distributed study of the geomorphology of intertidal areas, such as tidal flats and marshes, remains problematic owing to the small relief characterizing such environments, often of the order of a few tens of centimetres, i.e. comparable to the accuracy of state-of-the-art LiDAR data. Here we present the results of Terrestrial Laser Scanner (TLS) acquisitions performed within a tidal marsh in the Venice lagoon. The survey was performed using a Leica HDS 3000 TLS, characterized by a large Field of View (360 deg H x 270 deg V), a low beam divergence (DSM and a DTM. This is important e.g. in eco-geomorphic studies of intertidal environments, where conventional LiDAR technologies cannot easily separate first and last laser returns (because of the low vegetation height) and thus provide models of the surface as well as of the terrain. Furthermore, the DTM is shown to provide unprecedented characterizations of marsh morphology, e.g. regarding the cross-sectional properties of small-scale tidal creeks (widths of the order of 10 cm), previously observable only through conventional topographic surveys, thus not allowing a fully spatially-distributed description of their morphology.

  1. Fluvial geomorphology on Earth-like planetary surfaces: A review.

    Science.gov (United States)

    Baker, Victor R; Hamilton, Christopher W; Burr, Devon M; Gulick, Virginia C; Komatsu, Goro; Luo, Wei; Rice, James W; Rodriguez, J A P

    2015-09-15

    Morphological evidence for ancient channelized flows (fluvial and fluvial-like landforms) exists on the surfaces of all of the inner planets and on some of the satellites of the Solar System. In some cases, the relevant fluid flows are related to a planetary evolution that involves the global cycling of a volatile component (water for Earth and Mars; methane for Saturn's moon Titan). In other cases, as on Mercury, Venus, Earth's moon, and Jupiter's moon Io, the flows were of highly fluid lava. The discovery, in 1972, of what are now known to be fluvial channels and valleys on Mars sparked a major controversy over the role of water in shaping the surface of that planet. The recognition of the fluvial character of these features has opened unresolved fundamental questions about the geological history of water on Mars, including the presence of an ancient ocean and the operation of a hydrological cycle during the earliest phases of planetary history. Other fundamental questions posed by fluvial and fluvial-like features on planetary bodies include the possible erosive action of large-scale outpourings of very fluid lavas, such as those that may have produced the remarkable canali forms on Venus; the ability of exotic fluids, such as methane, to create fluvial-like landforms, as observed on Saturn's moon, Titan; and the nature of sedimentation and erosion under different conditions of planetary surface gravity. Planetary fluvial geomorphology also illustrates fundamental epistemological and methodological issues, including the role of analogy in geomorphological/geological inquiry.

  2. Spatial impact and triggering conditions of the exceptional hydro-geomorphological event of December 1909 in Iberia

    Science.gov (United States)

    Pereira, S.; Ramos, A. M.; Zêzere, J. L.; Trigo, R. M.; Vaquero, J. M.

    2016-02-01

    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

  3. 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.

    2012-01-01

    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

  4. Student-Produced Podcasts as an Assessment Tool: An Example from Geomorphology

    Science.gov (United States)

    Kemp, Justine; Mellor, Antony; Kotter, Richard; Oosthoek, Jan W.

    2012-01-01

    The emergence of user-friendly technologies has made podcasting an accessible learning tool in undergraduate teaching. In a geomorphology course, student-produced podcasts were used as part of the assessment in 2008-2010. Student groups constructed radio shows aimed at a general audience to interpret and communicate geomorphological data within…

  5. Teaching Topographic Map Skills and Geomorphology Concepts with Google Earth in a One-Computer Classroom

    Science.gov (United States)

    Hsu, Hsiao-Ping; Tsai, Bor-Wen; Chen, Che-Ming

    2018-01-01

    Teaching high-school geomorphological concepts and topographic map reading entails many challenges. This research reports the applicability and effectiveness of Google Earth in teaching topographic map skills and geomorphological concepts, by a single teacher, in a one-computer classroom. Compared to learning via a conventional instructional…

  6. Groundwater arsenic contamination from parts of the Ghaghara Basin, India: influence of fluvial geomorphology and Quaternary morphostratigraphy

    Science.gov (United States)

    Shah, Babar Ali

    2017-09-01

    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.

  7. Large-scale river regulation

    International Nuclear Information System (INIS)

    Petts, G.

    1994-01-01

    Recent concern over human impacts on the environment has tended to focus on climatic change, desertification, destruction of tropical rain forests, and pollution. Yet large-scale water projects such as dams, reservoirs, and inter-basin transfers are among the most dramatic and extensive ways in which our environment has been, and continues to be, transformed by human action. Water running to the sea is perceived as a lost resource, floods are viewed as major hazards, and wetlands are seen as wastelands. River regulation, involving the redistribution of water in time and space, is a key concept in socio-economic development. To achieve water and food security, to develop drylands, and to prevent desertification and drought are primary aims for many countries. A second key concept is ecological sustainability. Yet the ecology of rivers and their floodplains is dependent on the natural hydrological regime, and its related biochemical and geomorphological dynamics. (Author)

  8. Anisotropy of streambed sediments of contrasting geomorphological environments and its relation to groundwater discharge

    Science.gov (United States)

    Sebok, Eva; Duque, Carlos; Engesgaard, Peter; Bøgh, Eva

    2013-04-01

    several orders of magnitude, between 0.5 and 1655 were observed with the least variability close to the streambanks. Kv values show greater changes between measurement seasons than Kh, possibly due to changes in the streambed surface sediments. Based on the correlation between streambed hydraulic conductivity, anisotropy and geomorphological characteristics, results were also related to different streambed sediments, thus giving a comprehensive survey of the main factors affecting groundwater discharge to streams and hyporheic flow, some of the major issues in contamination of gaining rivers.

  9. Glacier beds that will be exposed in the future: How will geomorphologic and hydrologic processes develop?

    Science.gov (United States)

    Linsbauer, Andreas; Paul, Frank; Haeberli, Wilfried

    2014-05-01

    The rapid shrinkage of glaciers in the Alps has widespread impacts on relief development and hydrology. Slope failures, collapse of lateral moraines, loose debris in glacier fore-fields, new lakes and changing river beds are among the most visible impacts. They already require increased attention by tourists, monitoring by local authorities and mitigation measures (e.g. www.gletschersee.ch). A view into potential future developments (after glaciers have disappeared) is thus of high interest. With recently developed models that reconstruct glacier bed topography from easily available datasets (e.g. glacier outlines and a DEM) over entire mountain ranges, potential developments of the landscape and hydrology can be quantitatively determined. The modelled glacier beds - though they must be seen as a rough first order approximation only - also allows the investigation of a wide range of glaciological relations and dependencies that have been widely applied but were never investigated for a large sample of glaciers so far. A key reason is that information on glacier thickness distribution and total ice volume is sparse and that the future development of glaciers can only be modelled realistically when a glacier bed is available. Hence, with the glacier beds now available there is a larger number of geomorphological, glaciological and hydrological studies ahead of us. This presentation is providing an overview on the lessons learned about glaciers and their future development from the modelled glacier beds, the expected changes in hydrology (e.g. decreasing glacier volume and formation of new lakes) and potential impacts from the altered geomorphology (e.g. debuttressing of rock walls). In particular the flat tongues of larger valley glaciers are rather thick and leave oversteepened lateral moraines or rock walls behind, towering above overdeepenings in the glacier bed that might be filled with water. It is thus expected that the hazard potential will further increase in

  10. Quantification of the cumulative effects of river training works on the basin scale with 2D flood modelling

    Science.gov (United States)

    Zischg, Andreas Paul; Felder, Guido; WWeingartner, Rolf

    2015-04-01

    The catchment of the river Aare upstream of Bern, Switzerland, with an area of approx. 3000 km2 is a complex network of sub-catchments with different runoff characteristics; it also includes two larger lakes. Most of the rivers were regulated in the 18th century. An important regulation, however, was realised as early as in the 17th century. For this catchment, the worst case flood event was identified and its consequences were analysed. Beside the hydro-meteorological characteristics, an important basis to model the worst case flood is to understand the non-linear effects of flood retention in the valley bottom and in the lakes. The aim of this study was to compare these effects based on both the current river network and the historic one prior to the main river training works. This allows to quantify the human impacts. Methodologically, we set up a coupled 2D flood model representing the floodplains of the river Aare as well as of the tributaries Lombach, Lütschine, Zulg, Rotache, Chise and Guerbe. The flood simulation was made in 2D with the software BASEMENT-ETH (Vetsch et al. 2014). The model was calibrated by means of reproducing the large floods in August 2005 and the bankfull discharge for all river reaches. The model computes the discharge at the outlet of the Aare catchment at Bern by routing all discharges from the sub-catchments through the river reaches and their floodplains. With this, the modulation of the input hydrographs by widespread floodings in the floodplains can be quantified. The same configuration was applied on the basis of reconstructed digital terrain models representing the landscape and the river network before the first significant river training works had been realised. This terrain model was reconstructed by georeferencing and digitalizing historic maps and cross-sections combined with the mapping of the geomorphologic evidences of former river structures in non-modified areas. The latter mapping procedure was facilitated by the

  11. The coastal landscape of the river of silver basis for management

    International Nuclear Information System (INIS)

    Martinez, A.; Fernandez, E.; Cendom, A.; Vila, L.

    2013-01-01

    A complex of morphogenic, ecologic and cultural factors converge in coastal landscape modelling. The goal of this research is to identify the coastal environment as a water-land interphase in the Rio de la Plata, Uruguay. The area of work is within Punta Gorda, Colonia Department, and Maldonado River, in the Maldonado Department. An integrated landscape approach is used to interpret the complex of natural areas. The knowledge of natural complex is the goal of this research using the vegetation dynamic as an expression of site condition. Cartography at scale 1:50.000, colour composition of Landsat images at scale 1:100.000 (1994), aerial photographs at scale 1:10.000 (1994), are the source of information. A methodology of three components was organized: a typology of the coastal border, scale 1:500.000, a littoral morphology analysis using maps and aerial photographs, scale 1:10.000 and the coastal landscape, scale 1:100.000. A land cover legend was organized to integrate: geomorphology, vegetation and human intervention. It has 12 classes y 4 subclasses of land cover. This information was integrated in an analysis of an ideal coastal outline that represents the ideal disposition of the landscape elements in a cross and vertical perspective. The final goal of this research is an inventory of coastal uniform sectors. The research was performed within an approach of environmental factors equilibrium, such as geomorphology, environment, biologic and anthropogenic, and natural’s process in progress. Specific and general coastal problems are identified. A conceptual coastal landscape approach, a coastal cartography and setting of landscape units are the final products

  12. Hydrology, sediment transport dynamics and geomorphology of a ...

    African Journals Online (AJOL)

    The co-efficient of variation for inter-annual streamflow of the Mfolozi River is extremely high at 79%. An analysis of flow frequency indicated that streamflow is skewed towards low-flow values, with a number of extremely large flood events occurring as outliers on the histogram. Streamflow variability in the Mfolozi River may ...

  13. The hydro-geomorphological event of December 1909 in Iberia: social impacts and triggering conditions

    Science.gov (United States)

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

    2015-04-01

    22nd of December mainly associated to severe floods generated in the Douro and Tagus hydrographic basins. The atmospheric circulation during the December 1909 and prior months was assessed at the monthly, daily and sub-daily scales. This was achieved with the 20th Century Reanalysis from the National Oceanic and Atmospheric Administration/Earth System Research Laboratory Physical Sciences Division (NOAA/ERSL PSD), where several fields were analysed related to both surface and different tropospheric levels. Results show that, between 20 and 22 of December, a low pressure system become stationary over the North Atlantic Ocean near Azores, moving towards the British Isles and its frontal system affected the Iberian Peninsula on the 21 and 22 of December. The intense precipitation observed on the 22nd of December was also associated to a combination of wind and specific moisture characteristics at 900hPa (concentrated in a quite narrow strip) clearly suggesting the presence of an Atmospheric River. Compo, G. P., et al. (2011) The twentieth century reanalysis project. Quart. J. Roy. Meteor. Soc., 137A, 1-28 Zêzere, J. L., et al. (2014) DISASTER: a GIS database on hydro-geomorphologic disasters in Portugal. Nat. Hazards, 71: 1029-1050 This research was supported by the Portuguese Foundation for Science and Technology (FCT). The first author is a Post-Doc fellow funded by FCT (SFRH/BPD/69002/2010).

  14. Quantitative evaluation of the risk induced by dominant geomorphological processes on different land uses, based on GIS spatial analysis models

    Science.gov (United States)

    Ştefan, Bilaşco; Sanda, Roşca; Ioan, Fodorean; Iuliu, Vescan; Sorin, Filip; Dănuţ, Petrea

    2017-12-01

    Maramureş Land is mostly characterized by agricultural and forestry land use due to its specific configuration of topography and its specific pedoclimatic conditions. Taking into consideration the trend of the last century from the perspective of land management, a decrease in the surface of agricultural lands to the advantage of built-up and grass lands, as well as an accelerated decrease in the forest cover due to uncontrolled and irrational forest exploitation, has become obvious. The field analysis performed on the territory of Maramureş Land has highlighted a high frequency of two geomorphologic processes — landslides and soil erosion — which have a major negative impact on land use due to their rate of occurrence. The main aim of the present study is the GIS modeling of the two geomorphologic processes, determining a state of vulnerability (the USLE model for soil erosion and a quantitative model based on the morphometric characteristics of the territory, derived from the HG. 447/2003) and their integration in a complex model of cumulated vulnerability identification. The modeling of the risk exposure was performed using a quantitative approach based on models and equations of spatial analysis, which were developed with modeled raster data structures and primary vector data, through a matrix highlighting the correspondence between vulnerability and land use classes. The quantitative analysis of the risk was performed by taking into consideration the exposure classes as modeled databases and the land price as a primary alphanumeric database using spatial analysis techniques for each class by means of the attribute table. The spatial results highlight the territories with a high risk to present geomorphologic processes that have a high degree of occurrence and represent a useful tool in the process of spatial planning.

  15. Glaciation style and the geomorphological record: evidence for Younger Dryas glaciers in the eastern Lake District, northwest England

    Science.gov (United States)

    McDougall, Derek

    2013-08-01

    The Younger Dryas (c. 12,900-11,700 years ago) in Britain witnessed renewed glaciation, with the readvance of ice masses that had survived the preceding Lateglacial Interstadial as well as the formation of new glaciers. The extents of these former glaciers have been mapped by many workers over the past fifty years, usually as a basis for palaeoclimatic investigations. It has frequently been asserted that the landform record is sufficiently clear to allow accurate ice mass reconstructions at or near maximum extents. Detailed geomorphological mapping in the eastern Lake District in NW England, however, demonstrates that this confidence may not always be warranted. Whereas previous workers have interpreted the well-developed moraines that exist in some locations as evidence for an alpine-style of glaciation, with ice restricted to a small number of valleys, this study shows that the most recent glaciation to affect the area was characterised by: (i) extensive summit icefields, which supplied ice to the surrounding valleys; and (ii) a much greater volume of ice in the valleys than previously thought. The discovery that summit icefields were relatively common at this time is consistent with recent studies elsewhere in the Lake District and beyond. More significant, however, is the recognition that changing glacier-topographic interactions over both space and time appears to have had a profound impact on valley-floor glacial landform development, with the absence of clear moraines not necessarily indicating ice-free conditions at this time. This complicates glacier reconstructions based solely on the geomorphological record. Similar geomorphological complexity may be present in other areas that previously supported summit icefields, and this needs to be taken into account in glacier reconstructions.

  16. Quantitative evaluation of the risk induced by dominant geomorphological processes on different land uses, based on GIS spatial analysis models

    Science.gov (United States)

    Ştefan, Bilaşco; Sanda, Roşca; Ioan, Fodorean; Iuliu, Vescan; Sorin, Filip; Dănuţ, Petrea

    2018-06-01

    Maramureş Land is mostly characterized by agricultural and forestry land use due to its specific configuration of topography and its specific pedoclimatic conditions. Taking into consideration the trend of the last century from the perspective of land management, a decrease in the surface of agricultural lands to the advantage of built-up and grass lands, as well as an accelerated decrease in the forest cover due to uncontrolled and irrational forest exploitation, has become obvious. The field analysis performed on the territory of Maramureş Land has highlighted a high frequency of two geomorphologic processes — landslides and soil erosion — which have a major negative impact on land use due to their rate of occurrence. The main aim of the present study is the GIS modeling of the two geomorphologic processes, determining a state of vulnerability (the USLE model for soil erosion and a quantitative model based on the morphometric characteristics of the territory, derived from the HG. 447/2003) and their integration in a complex model of cumulated vulnerability identification. The modeling of the risk exposure was performed using a quantitative approach based on models and equations of spatial analysis, which were developed with modeled raster data structures and primary vector data, through a matrix highlighting the correspondence between vulnerability and land use classes. The quantitative analysis of the risk was performed by taking into consideration the exposure classes as modeled databases and the land price as a primary alphanumeric database using spatial analysis techniques for each class by means of the attribute table. The spatial results highlight the territories with a high risk to present geomorphologic processes that have a high degree of occurrence and represent a useful tool in the process of spatial planning.

  17. Interaction between rivers and bridges in Tuscany (Italy)

    Science.gov (United States)

    Tartaglia, V.; Caporali, E.

    2003-04-01

    The natural adjustment phenomena of the rivers next to the crossing infrastructures, often due to the interaction with the structures themselves, cause damage risk conditions for a high number of structures. About 30 railway bridge sites in Tuscany, interested in the last 30 years by river bed instability, have been monitored. A standardized Bridge Site Inspection Form have been defined and used for the inspections to ensure data reliability and a computer-aided system for data collection have been developed. The system is composed by two components: (1) a GIS that contain the hydrological and geomorphological data layers; (2) a DBMS on which the geomorphological characteristics of the sites and the geometrical and structural characteristics of the bridges are stored with a relational structure. The observed damage mechanisms suggest to schematise the bridge-river interaction as the sum of two instability processes: (a) the lateral instability, when long term evolution of the stream or localized collapse phenomena of the banks can undermine the lateral bridge structures not meant to be exposed to flow (piers whit shallow foundation in the floodplain, long abutments, etc.); (b) vertical instability processes, when the river bed level degradation given by the sum of geomorphological phenomena at the basin scale (general scour) and at the site scale (contraction scour and local scour) can undermine the bridge foundations. To express synthetically the damage risk of bridges, due to instability phenomena of their crossed rivers, the use of a Risk Index is here proposed. The RI is calculated with a semi-qualitative method derived from the geomorphological observations and from the calculated values of some hydraulic variables, obtained by the regional frequency analysis of flood in Tuscany. The RI allows, even in lack of foundation depth data, to individuate the critical sites and to rank them for protection planning. Besides a threshold value of the Risk Index has been

  18. Surficial geology and geomorphology of Potter County, Pennsylvania

    Science.gov (United States)

    Denny, C.S.

    1956-01-01

    Potter County is located in the Appalachian Plateaus of north-central Pennsylvania and contains the headwaters of the Genesee River, the Allegheny River, and the Susquehanna River. Drift of Wisconsin age covers the northeastern part of the county. This study includes a detailed survev of the surficial deposits of the Genesee quadrangle in north-central Potter County and a reconnaissance of the remainder of the county; a soil survey and a botanical survey were carried on concurrently. The region is a deeply dissected plateau having extensive areas of steeply sloping land separated by narrow ridges and valleys; there is very little level land. Near the junction of the three watersheds the uplands rise to altitudes of more than 2,500 feet. The maximum relief in the Susquehanna drainage is more than 1,500 feet; in the Genesee and Allegheny drainage it. is about 800 feet. Valley walls are steep (15° to 30°), and the uplands have gentle slopes (0.5° to 10°). The drainage pattern is trellised. The climate is continental. Temperatures range from about -30° F. to more than 100° F. The average annual precipitation ranges approximately from 34 to 42 inches. Floods may occur at any season of the year. The large volumes of water from rain or melting snow carried by small streams come from springs. There is little precise data on frost in the ground, but it is probable that the ground seldom freezes in forested areas. The soils of Potter County have relatively immature profiles with poorly developed horizons that commonly have many characteristics inherited from their parent materials. At the great soil group level, the zonal soils are divided into Podzol soils and Brown Podzolic soils. Many soils have a high silt content in the upper part of the profile, apparently derived (at least partly) from a mantle of eolian silt. Mos~ of Potter County is covered by second-growth forests consisting of 40- to 60-year-old hardwood stands. The present forests growing on slopes and

  19. Geomorphological processes in Britain in a periglacial age

    International Nuclear Information System (INIS)

    Pitty, A.F.

    1988-12-01

    Significant changes in geomorphological processes can be anticipated over the timescales relevant to the Safety Assessments being formulated by United Kingdom Nirex Ltd. The opening sections of this Report emphasise the intrinsic uncertainties concerning the study and interpretation of periglacial phenomena, both in their present-day setting, and as presumed relict features in the British Isles. A section illustrates how emphases have veered and varied in this area of study. An implication, with particular reference to the British Isles, is that the study of periglacial phenomena is, itself, subject to significant short-term changes. The Report reviews the climate of a periglacial environment, emphasising the difficulties involved in translations from present-day analogue areas, which often have intrinsic differences, when compared with the British Isles. The significance of frost penetration, microclimate and snow cover is explained. (Author)

  20. On geo-basis of river regulation——A case study for the middle reaches of the Yangtze River

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    From the point of view that people have to obey the river’s geo-attributes in the river regulation, the definition and the meaning of the geo-attributes of a river are discussed. The geo-basis of the river regulation of the middle reaches of the Yangtze River is expounded in five aspects, including the structural geomorphology environment of flood storage and discharge, the distribution characteristics of subsidence and the sedimentation areas of Dongting Basin, the history evolution of Jianghan Basin, the function of Jianghan Basin and Dongting Basin as the flood water detention areas of Jingjiang River reach in ancient time, and the geological characteristic of Jingjiang River reach. Based on the geo-attributes of the middle reaches of the Yangtze River, some ideas about the middle reach regulation of the Yangtze River are put forward: to process the interchange between the lakes and diked marsh areas in Dongting Basin, to canal the new river route as the flood diversion channel of Jingjiang River reach with the paleo river, to recover the function of Jianghan Basin as flood detention area of the middle reaches. And we should take into consideration the geo-environment of the whole Yangtze River in the river regulation of middle reaches.

  1. A brief history and summary of the effects of river engineering and dams on the Mississippi River system and delta

    Science.gov (United States)

    Alexander, Jason S.; Wilson, Richard C.; Green, W. Reed

    2012-01-01

    The U.S. Geological Survey Forecast Mekong project is providing technical assistance and information to aid management decisions and build science capacity of institutions in the Mekong River Basin. A component of this effort is to produce a synthesis of the effects of dams and other engineering structures on large-river hydrology, sediment transport, geomorphology, ecology, water quality, and deltaic systems. The Mississippi River Basin (MRB) of the United States was used as the backdrop and context for this synthesis because it is a continental scale river system with a total annual water discharge proportional to the Mekong River, has been highly engineered over the past two centuries, and the effects of engineering have been widely studied and documented by scientists and engineers. The MRB is controlled and regulated by dams and river-engineering structures. These modifications have resulted in multiple benefits including navigation, flood control, hydropower, bank stabilization, and recreation. Dams and other river-engineering structures in the MRB have afforded the United States substantial socioeconomic benefits; however, these benefits also have transformed the hydrologic, sediment transport, geomorphic, water-quality, and ecologic characteristics of the river and its delta. Large dams on the middle Missouri River have substantially reduced the magnitude of peak floods, increased base discharges, and reduced the overall variability of intraannual discharges. The extensive system of levees and wing dikes throughout the MRB, although providing protection from intermediate magnitude floods, have reduced overall channel capacity and increased flood stage by up to 4 meters for higher magnitude floods. Prior to major river engineering, the estimated average annual sediment yield of the Mississippi River Basin was approximately 400 million metric tons. The construction of large main-channel reservoirs on the Missouri and Arkansas Rivers, sedimentation in dike

  2. Floodplain hydrodynamic modelling of the Lower Volta River in Ghana

    Directory of Open Access Journals (Sweden)

    Frederick Yaw Logah

    2017-12-01

    Full Text Available The impacts of dam releases from re-operation scenarios of the Akosombo and Kpong hydropower facilities on downstream communities along the Lower Volta River were examined through hydrodynamic modelling using the HEC-RAS hydraulic model. The model was used to simulate surface water elevation along the river reach for specified discharge hydrographs from proposed re-operation dam release scenarios. The morphology of the river and its flood plains together with cross-sectional profiles at selected river sections were mapped and used in the hydrodynamic modelling. In addition, both suspended and bed-load sediment were sampled and analysed to determine the current sediment load of the river and its potential to carry more sediment. The modelling results indicate that large areas downstream of the dam including its flood plains would be inundated if dam releases came close to or exceeded 2300 m3/s. It is therefore recommended to relocate communities along the banks and in the flood plains of the Lower Volta River when dam releases are to exceed 2300 m3/s. Suspended sediment transport was found to be very low in the Lower Volta River and the predominant soil type in the river banks and bed is sandy soil. Thus, the geomorphology of the river can be expected to change considerably with time, particularly for sustained high releases from the Akosombo and Kpong dams. The results obtained from this study form a basis for assessing future sedimentation problems in the Lower Volta River and for underpinning the development of sediment control and management strategies for river basins in Ghana. Keywords: Geomorphology, HEC-RAS model, Dam release, Floodplain, Lower Volta River, Ghana

  3. Geology, Surficial, Neuse River Basin Mapping Project Core Locations �Äö?Ñ?¨ Ongoing project in Middle Coastal Plain to characterize geomorphology, surficial geology, and shallow aquifers and confining units; Excel spread sheet with core names, coordinates, and data co, Published in 2006, 1:24000 (1in=2000ft) scale, North Carolina Department of Environment and Natural Resources (DENR).

    Data.gov (United States)

    NSGIC State | GIS Inventory — Geology, Surficial dataset current as of 2006. Neuse River Basin Mapping Project Core Locations �Äö?Ñ?¨ Ongoing project in Middle Coastal Plain to characterize...

  4. The anthropogenic nature of present-day low energy rivers in western France and implications for current restoration projects

    Science.gov (United States)

    Lespez, L.; Viel, V.; Rollet, A. J.; Delahaye, D.

    2015-12-01

    As in other European countries, western France has seen an increase in river restoration projects. In this paper, we examine the restoration goals, methods and objectives with respect to the long-term trajectory and understanding of the contemporary dynamics of the small low energy rivers typical of the lowlands of Western Europe. The exhaustive geomorphological, paleoenvironmental and historical research conducted in the Seulles river basin (Normandy) provides very accurate documentation of the nature and place of the different legacies in the fluvial systems we have inherited. The sedimentation rate in the Seulles valley bottom has multiplied by a factor of 20 since the end of the Bronze Age and has generated dramatic changes in fluvial forms. Hydraulic control of the rivers and valley bottoms drainage throughout the last millennium has channelized rivers within these deposits. The single meandering channel which characterizes this river today is the legacy of the delayed and complex effects of long term exploitation of the river basin and the fluvial system. Bring to light that the "naturalness" of the restored rivers might be questioned. Our research emphasizes the gap between the poor knowledge of the functioning of these rivers and the concrete objectives of the restoration works undertaken, including dam and weir removal. Account of the long-term history of fluvial systems is required, not only to produce a pedagogic history of the "river degradation" but more fundamentally (i) to situate the current functioning of the fluvial system in a trajectory to try to identify thresholds and anticipate the potential turning points in a context of climate and land use change, (ii) to understand the role of morphosedimentary legacies on the current dynamics, (iii) to open the discussion on reference functioning or expected states and (iv) to open discussion on the sustainability of ecological restoration. To conclude, we point out the necessity to take into account the

  5. Historic (1940 to present) changes in Lillooet River planform (BC, Canada)

    Science.gov (United States)

    Zei, Caterina

    2017-04-01

    Historic (1940 to present) changes in Lillooet River planform (BC, Canada) Zei C.*, Giardino M.*, Perotti L.*, Roberti G.***, **Ward B.C.**, Clague J.J.** *Department of Earth Sciences, Geositlab, Università degli Studi di Torino, Torino, Italia; **Department of Earth Sciences, Simon Fraser University, Burnaby, British Columbia, Canada ***Université Blaise Pascal - Laboratoire Magmas et Volcans Clermont-Ferrand, France We conducted a geomorphological study of changes in the planform of Lillooet River (Coast Mountain, British Columbia, Canada) over the past 75 years. The study involved identification and interpretations of channel changes in the reach of the river between Mount Meager (the source of the landslide) and Pemberton Meadows. Lillooet River flows about 95 km southeast from its headwaters at Lillooet Glacier to Lillooet Lake near Pemberton, the largest community in the valley. Between the mouth of Meager Creek and Pemberton Meadows, the river is unregulated and has a braided planform resulting from the very high delivery of sediment due to frequent landslides and debris flows sourced on the Mount Meager volcanic complex. Below Pemberton Meadows, the river occupies a single channel confined between dikes. A rich archive of historical vertical aerial photographs exists for the study area, In addition, a high-resolution digital elevation model was produced from LiDAR data acquired in 2015. We processed each set of photos dating back to 1940 with the software Agisoft Photoscan to produce high resolution orthophotos. Analysis of these datasets, complemented with field investigation, showed that the river channel in the braided reach shifted laterally up to 550 m between 1981 and 2010; likely caused in part by five floods with peak discharges of more than 800 m^3/s and four landslides on the flanks of Mount Meager massif with volumes up to 13 x 106 m^3. Channel avulsions were probably triggered by accumulation of in-channel rafts of coarse woody debris and are

  6. Surface complexation modeling of groundwater arsenic mobility: Results of a forced gradient experiment in a Red River flood plain aquifer, Vietnam

    Science.gov (United States)

    Jessen, Søren; Postma, Dieke; Larsen, Flemming; Nhan, Pham Quy; Hoa, Le Quynh; Trang, Pham Thi Kim; Long, Tran Vu; Viet, Pham Hung; Jakobsen, Rasmus

    2012-12-01

    Three surface complexation models (SCMs) developed for, respectively, ferrihydrite, goethite and sorption data for a Pleistocene oxidized aquifer sediment from Bangladesh were used to explore the effect of multicomponent adsorption processes on As mobility in a reduced Holocene floodplain aquifer along the Red River, Vietnam. The SCMs for ferrihydrite and goethite yielded very different results. The ferrihydrite SCM favors As(III) over As(V) and has carbonate and silica species as the main competitors for surface sites. In contrast, the goethite SCM has a greater affinity for As(V) over As(III) while PO43- and Fe(II) form the predominant surface species. The SCM for Pleistocene aquifer sediment resembles most the goethite SCM but shows more Si sorption. Compiled As(III) adsorption data for Holocene sediment was also well described by the SCM determined for Pleistocene aquifer sediment, suggesting a comparable As(III) affinity of Holocene and Pleistocene aquifer sediments. A forced gradient field experiment was conducted in a bank aquifer adjacent to a tributary channel to the Red River, and the passage in the aquifer of mixed groundwater containing up to 74% channel water was observed. The concentrations of As (SCM correctly predicts desorption for As(III) but for Si and PO43- it predicts an increased adsorption instead of desorption. The goethite SCM correctly predicts desorption of both As(III) and PO43- but failed in the prediction of Si desorption. These results indicate that the prediction of As mobility, by using SCMs for synthetic Fe-oxides, will be strongly dependent on the model chosen. The SCM based on the Pleistocene aquifer sediment predicts the desorption of As(III), PO43- and Si quite superiorly, as compared to the SCMs for ferrihydrite and goethite, even though Si desorption is still somewhat under-predicted. The observation that a SCM calibrated on a different sediment can predict our field results so well suggests that sediment based SCMs may be a

  7. Synthesis of Upper Verde River research and monitoring 1993-2008

    Science.gov (United States)

    Daniel G. Neary; Alvin L. Medina; John N. Rinne

    2012-01-01

    This volume is a state-of-knowledge synthesis of monitoring and research conducted on the Upper Verde River (UVR) of Arizona. It contains information on the history, hydrology, soils, geomorphology, vegetation, and fish fauna of the area that can help land managers and other scientists in successfully conducting ecosystem management and future monitoring and research...

  8. Relationships of vascular epiphytes with environmental factors along the Tibagi River forests, Paraná, Brazil

    Directory of Open Access Journals (Sweden)

    Annete Bonnet

    2010-09-01

    Full Text Available The aim of this work was to evaluate the relationships of vascular epiphyte richness with climatic, geomorphologic, pedologic and forest structural factors, that change along the Tibagi River. The floristic turnover of the 188 registered species was high, indicating the singularity and importance of the communities to the conservation of epiphytes in the river basin. The similarity was greater between geographically closer areas, which made possible the creation of three groups of epiphytic communities distributed along the river. The greatest richness of epiphytes was registered in the medium Tibagi, where the phytogeographic units are in liaison and the forests present the best conservation status. The increase of epiphytic richness is only significantly and positively related to the maximal diameter of trees, an important environmental factor of the enlargement of alpha diversity. The beta diversity results, probably, from environmental heterogeneity which is principally represented by distinctive geomorphologic patterns and climatic conditions between study areas and different environmental regions of the river.

  9. Recent advances in research on the aeolian geomorphology of China's Kumtagh Sand Sea

    Science.gov (United States)

    Dong, Z.; Lv, P.

    2014-02-01

    The Kumtagh Sand Sea in the hyper-arid region of northwestern China remained largely unexplored until the last decade. It deserves study due to its significance in understanding the evolution of the arid environments in northwestern China, and even central Asia. Aeolian geomorphology in the sand sea has received unprecedented study in the last decade. Encouraging advances have been made in types of aeolian landforms, geological outlines, wind systems, the formation of aeolian landforms, several unique aeolian landforms, aeolian geomorphic regionalization, aeolian geomorphological heritages and tourism development, and aeolian sand hazards and their control. These advances expand our knowledge of aeolian geomorphology.

  10. Assessment of present day geomorphological dynamics to decipher landscape evolution around the Paleolithic sites of Melka Kunture, Ethiopia

    Science.gov (United States)

    Maerker, Michael; Schillaci, Calogero; Melis, Rita; Mussi, Margherita

    2014-05-01

    The area of Melka Kunture (central Ethiopia) is one of the most important clusters of Paleolithic sites in Eastern Africa. The archaeological record spans from c. 1.7 Ma onwards, with a number of stratified occurrences of Oldowan, Acheulean, Middle Stone Age and Late Stone Age industries, together with faunal remains and human fossils. However, the archaeological sites are endangered by flooding and soil erosion. The main excavation area lies close to the convergence of the Awash river with the Atabella river, one of the main tributaries of the upper Awash catchment. In the semi-arid Ethiopian highlands, gully networks develop especially in the vicinity of the active and inactive river meanders. Various erosion processes are linked to specific driving factors such as the rainfall regime, the land use/cover changes and vertic soils with a specific hydrological behaviour. It was documented in the field and by previous research that the origin of most of the man made erosion channels is due to animal pathways and car tracks. However, paleolandscape features increase the general erosion risk. Former wetland areas and deposition zones are particularly affected by soil erosion processes. Hence, the spatial distribution and characteristics of present day geomorphic processes also reveal information on the paleolandscape. In order to assess landscape evolution and present day geomorphologic dynamics, we mapped the geomorphology describing in detail the present-day slope processes at a 10.000 scale. We performed a detailed terrain analysis based on high resolution DEMs such as SRTM-X with 25m resolution and ALOS/PRISM with 10m resolution to characterize the main erosion processes and surface runoff dynamics. The latter ones are simulated using a Soil Conservation Service Curve Number method. Landuse was delineated for a larger area using ASTER 25m multispectral data. Finally, using calibrated topographic indices and a simple hydrological model we were able to detect and

  11. Hydrology, sediment transport dynamics and geomorphology of a ...

    African Journals Online (AJOL)

    2009-01-21

    Jan 21, 2009 ... 1 School of Environmental Science, Memorial Tower Building, Howard College Campus, University ... Furthermore, data suggested the existence of long-term .... the period of record for the Mfolozi River was short, the analysis.

  12. Heavy mineral analyses as a powerful tool in fluvial geomorphology

    Science.gov (United States)

    von Suchodoletz, Hans; Gärtner, Andreas; Faust, Dominik

    2014-05-01

    The Marneuli depression is a tectonic sub-basin of the Transcaucasian depression in eastern Georgia, filled with several decametres of fluvial, lacustrine and aeolian Quaternary sediments. In order to reconstruct past landscape evolution of the region we studied Late Quaternary fluvial sediments found along several rivers that flow through that depression. Whereas Holocene river sediments could generally easily be assigned to corresponding rivers, this was not always the case for older fluvial sediments. For this reason, we studied the heavy mineral contents of five recent rivers and of four sedimentary deposits of potential precursors. A total of 4088 analysed heavy mineral grains enabled us to set up the characteristic heavy mineral distribution pattern for each sample. Using these data, we were able to reconstruct the most likely source areas of the Late Pleistocene fluvial sediments and to link them with the catchment areas of recent rivers. This allowed us to identify and to substantiate significant Late Quaternary river diversions that could at least partly be assigned to ongoing tectonic processes.

  13. River engineering

    NARCIS (Netherlands)

    De Vries, M.

    1993-01-01

    One dimension models - basic eauations, analytical models, numberical models. One dimensional models -suspended load, roughness and resistance of river beds. Solving river problems - tools, flood mitigation, bank protection.

  14. Archaeology, Geomorphology and Historic Surveys in Pools 13-14, Upper Mississippi River. Volume 1

    Science.gov (United States)

    1989-09-01

    sold for $5, $10, or $50 an acre. Townsites were platted by the hundreds: In some embryo towns, corner lots sold for $500 in the morning might be sold...Mexico in the name of "Manifest Destiny " secures California and much of northern Mex ico for the United I States. 1848 California Gold Rush., Gold is

  15. Archaeology and Geomorphology of Red Oak Ridge Island, Navigation Pool 7, Upper Mississippi River Valley.

    Science.gov (United States)

    1986-02-01

    1884c, 1884d, 1885, 1887a, 1887b, 1889a, 1889b, 1889c , 1889d, 1889e, 1890, 1891a, 1891b, 1891c, 1892a, 1892b, 1892c, and 1895). Two Minnesota pioneer...Antiquarian and Oriental Journal. Vol. 11: 139-163. 1889c Burial Mounds Viewed as Monuments. The American Antiquarian and Oriental Journal. Vol. 11: 359-378

  16. Preliminary Cultural Resource Survey and Geomorphological Assessment of Selected Areas in Navigation Pool 16, Mississippi River.

    Science.gov (United States)

    1982-06-01

    and French defensive earthworks of the Battle of Yorktown. Amistad Paleoecology Study, 1964-66. I. co-directed this in- terdisiTplinary study, funded by...299 pp. 1965 (co-author, with John P. Nunley and Lathel F. Duffield) Ex- I cavations at Amistad Reservoir, 1962 Season. Miscellaneous Paper of the

  17. Development and Testing of Physically-Based Methods for Filling Gaps in Remotely Sensed River Data

    Science.gov (United States)

    2011-09-30

    Filling Gaps in Remotely Sensed River Data Jonathan M. Nelson US Geological Survey National Research Program Geomorphology and Sediment Transport...the research work carried out under this grant are to develop and test two methods for filling in gaps in remotely sensed river data. The first...information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215

  18. A micro case study of the legal and administrative arrangements for river health in the Kangaroo River (NSW).

    Science.gov (United States)

    Mooney, C; Farrier, D

    2002-01-01

    Kangaroo Valley is a drinking water supply catchment for Kangaroo Valley village, parts of the Southern Highlands and Sydney. It is also a popular recreation area both for swimming and canoeing. Land use has traditionally been dominated by dairy farming but there has been significant and continuing development of land for hobby farms and rural residential subdivision. Dairy industry restructuring has affected the viability of some farms in the Valley and created additional pressure for subdivision. River health is a function of flows, water quality, riparian vegetation, geomorphology and aquatic habitat and riverine biota. River flows in the Kangaroo River are affected by water extraction and storage for urban water supply and extraction by commercial irrigators and riparian land holders which have a significant impact at low flows. Current water quality often does not meet ANZECC Guidelines for primary contact and recreation and the river is a poor source of raw drinking water. Key sources of contaminants are wastewater runoff from agriculture, and poorly performing on-site sewage management systems. Riparian vegetation, which is critical to the maintenance of in-stream ecosystems suffers from uncontrolled stock access and weed infestation. The management of land use and resulting diffuse pollution sources is critical to the long term health of the river. The Healthy Rivers Commission of New South Wales Independent Inquiry into the Shoalhaven River System Final Report July, 1999 found that the longer term protection of the health of the Kangaroo River is contingent upon achievement of patterns of land use that have regard to land capability and also to the capability of the river to withstand the impacts of inappropriate or poorly managed land uses. This micro case study of Kangaroo Valley examines the complex legal and administrative arrangements with particular reference to the management of diffuse pollution for river health. In the past, diffuse pollution has

  19. On the issue of equifinality in glacial geomorphology

    Science.gov (United States)

    Möller, Per; Dowling, Thomas; Cleland, Carol; Johnson, Mark

    2016-04-01

    A contemporary trend in glacial geomorphology is the quest for some form of unifying theory for drumlin and/or ribbed moraine formation: there MUST be ONE explanation. The result of this is attempts to apply 'instability theory' to the formation of all drumlinoid and ribbed moraine formation or, as an alternative to this, the 'erodent layer hypothesis' for single processes driven formation. However, based on field geology evidence on internal composition and architecture and the internals relation to the exterior, i.e. the shape of drumlins or ribbed moraine, many glacial sedimentologists would argue that it is instead different processes in their own or in combination that lead to similar form, i.e. look-alike geomorphologic expression or equifinality in spite of different process background for their formation. As expressed by Cleland (2013) from a philosophical point of view of a 'common cause explanation', as exemplified with mass extinctions through geologic time, there is probably a 'common cause explanation' for the K/T boundary extinction (massive meteorite impact on Earth), but this is not a common explanation for every other mass extinction. The parallel to our Quaternary enigma is that there can of course be a single common cause for explaining a specific drumlinoid flow set (a particular case), but that does not have to be the explanation of another flow set showing other sedimentological/structural attributes, in turn suggesting that the particular case cause cannot be used for explaining the general case, i.e. all drumlins over glaciated terrain on the globe. We argue in the case of streamlined terrain, which often have considerable morphologic difference between features at local landscape scale whilst still remaining part of the drumlinoid continuum on regional scale, is a product of different processes or process combinations (erosion/deformation/accumulation) in the subglacial system, tending towards the most efficient obstacle shape and thus

  20. Elaboration Of A Classification Of Geomorphologic Units And The Basis Of A Digital Data-Base For Establishing Geomorphologic Maps In Egypt

    International Nuclear Information System (INIS)

    EI Gammal, E.A.; Cherif, O.H.; Abdel Aleem, E.

    2003-01-01

    A database for the classification and description of basic geomorphologic land form units has been prepared for establishing geomorphologic maps in Egyptian terrains. This database includes morpho-structural, lithological, denudational and depositional units. The database.is included in tables with proper coding to be used for establishing automatically the color, symbols and legend of the maps. Also the system includes description of various geomorphic units. The system is designed to be used with the ARC Map software. The AUTOCAD 2000 software has been used to trace the maps. The database has been applied to produce five new geomorphologic maps with a scale of I: 100 000. These are: Wadi Feiran Sheet, Wadi Kid Sheet, Gabal Katherina Sheet in South Sinai, Shelattein area (South Eastern Desert) and Baharia Oasis area (Western Desert)

  1. The timing of tertiary metamorphism and deformation in the Albion-Raft River-Grouse Creek metamorphic core complex, Utah and Idaho

    Science.gov (United States)

    Strickland, A.; Miller, E.L.; Wooden, J.L.

    2011-01-01

    The Albion-Raft River-Grouse Creek metamorphic core complex of southern Idaho and northern Utah exposes 2.56-Ga orthogneisses and Neoproterozoic metasedimentary rocks that were intruded by 32-25-Ma granitic plutons. Pluton emplacement was contemporaneous with peak metamorphism, ductile thinning of the country rocks, and top-to-thewest, normal-sense shear along the Middle Mountain shear zone. Monazite and zircon from an attenuated stratigraphic section in the Middle Mountain were dated with U-Pb, using a SHRIMP-RG (reverse geometry) ion microprobe. Zircons from the deformed Archean gneiss preserve a crystallization age of 2532 ?? 33 Ma, while monazites range from 32.6 ?? 0.6 to 27.1 ?? 0.6 Ma. In the schist of the Upper Narrows, detrital zircons lack metamorphic overgrowths, and monazites produced discordant U-Pb ages that range from 52.8 ?? 0.6 to 37.5 ?? 0.3 Ma. From the structurally and stratigraphically highest unit sampled, the schist of Stevens Spring, narrow metamorphic rims on detrital zircons yield ages from 140-110 Ma, and monazite grains contained cores that yield an age of 141 ??2 Ma, whereas rims and some whole grains ranged from 35.5 ?? 0.5 to 30.0 ?? 0.4 Ma. A boudinaged pegmatite exposed in Basin Creek is deformed by the Middle Mountains shear zone and yields a monazite age of 27.6 ?? 0.2 Ma. We interpret these data to indicate two periods of monazite and metamorphic zircon growth: a poorly preserved Early Cretaceous period (???140 Ma) that is strongly overprinted by Oligocene metamorphism (???32-27 Ma) related to regional plutonism and extension. ?? 2011 by The University of Chicago.

  2. Determination of Background Uranium Concentration in the Snake River Plain Aquifer under the Idaho National Engineering and Environmental Laboratory's Radioactive Waste Management Complex

    International Nuclear Information System (INIS)

    Molly K. Leecaster; L. Don Koeppen; Gail L. Olson

    2003-01-01

    Uranium occurs naturally in the environment and is also a contaminant that is disposed of at the Radioactive Waste Management Complex (RWMC) at the Idaho National Engineering and Environmental Laboratory. To determine whether uranium concentrations in the Snake River Plain Aquifer, which underlies the laboratory, are elevated as a result of migration of anthropogenic uranium from the Subsurface Disposal Area in the RWMC, uranium background concentrations are necessary. Guideline values are calculated for total uranium, 234U, 235U, and 238U from analytical results from up to five datasets. Three of the datasets include results of samples analyzed using isotope dilution thermal ionization mass spectrometry (ID-TIMS) and two of the datasets include results obtained using alpha spectrometry. All samples included in the statistical testing were collected from aquifer monitoring wells located within 10 miles of the RWMC. Results from ID-TIMS and alpha spectrometry are combined when the data are not statistically different. Guideline values for total uranium were calculated using four of the datasets, while guideline values for 234U were calculated using only the alpha spectrometry results (2 datasets). Data from all five datasets were used to calculate 238U guideline values. No limit is calculated for 235U because the ID-TIMS results are not useful for comparison with routine monitoring data, and the alpha spectrometry results are too close to the detection limit to be deemed accurate or reliable for calculating a 235U guideline value. All guideline values presented represent the upper 95% coverage 95% confidence tolerance limits for background concentration. If a future monitoring result is above this guideline, then the exceedance will be noted in the quarterly monitoring report and assessed with respect to other aquifer information. The guidelines (tolerance limits) for total U, 234U, and 238U are 2.75 pCi/L, 1.92 pCi/L, and 0.90 pCi/L, respectively

  3. Regional geology, tectonic, geomorphology and seismology studies to interest to nuclear power plants at Itaorna beach

    International Nuclear Information System (INIS)

    Hasui, Y.; Almeida, F.F.M. de; Mioto, J.A.; Melo, M.S. de.

    1982-01-01

    The study prepared for the nuclear power plants to be located at Itaorna comprised, the analysis and integration of Geologic, tectonic, geomorphologic and seismologic information and satisfactory results of regional stability were obtained. (L.H.L.L.) [pt

  4. Relief of the Podyjí National Park and Geomorphologic Aspects of its Protection (Czech Republic)

    Czech Academy of Sciences Publication Activity Database

    Kirchner, Karel; Demek, J.

    2009-01-01

    Roč. 83, č. 1 (2009), s. 91-98 Institutional research plan: CEZ:AV0Z30860518 Keywords : geomorphology * landscape protection * nature conservation * NP Podyji Subject RIV: DE - Earth Magnetism, Geodesy, Geography

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

    NARCIS (Netherlands)

    Wolfert, H.P.

    1995-01-01

    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,

  6. Geomorphology and surficial geology of the western continental shelf and slope of India: A review

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, V.P.; Wagle, B.G.

    Coastal geology and geomorphology of the area and nearshore currents played a significant role in the distribution of placer minerals off Kerala and Maharashtra. Transport and sedeimentation of fine-grained materials at places on the shelf...

  7. River Restoration and Meanders

    Directory of Open Access Journals (Sweden)

    G. Mathias Kondolf

    2006-12-01

    Full Text Available Among the most visually striking river restoration projects are those that involve the creation of a new channel, often in a new alignment and generally with a form and dimensions that are different from those of the preproject channel. These channel reconstruction projects often have the objective of creating a stable, single-thread, meandering channel, even on rivers that were not historically meandering, on rivers whose sediment load and flow regime would not be consistent with such stable channels, or on already sinuous channels whose bends are not symmetrical. Such meandering channels are often specified by the Rosgen classification system, a popular restoration design approach. Although most projects of this type have not been subject to objective evaluation, completed postproject appraisals show that many of these projects failed within months or years of construction. Despite its, at best, mixed results, this classification and form-based approach continues to be popular because it is easy to apply, because it is accessible to those without formal training in fluvial geomorphology, and probably because it satisfies a deep-seated, although unrecognized, cultural preference for single-thread meandering channels. This preference is consistent with 18th-century English landscape theories, which held the serpentine form to be ideal and led to widespread construction of meandering channels on the country estates of the era. The preference for stability in restored channels seems to be widely accepted by practitioners and funders despite the fact that it is antithetical to research showing that dynamically migrating channels have the greatest ecological richness.

  8. Geomorphological criteria applied to the study of the neotectonic of the internal areas of Spain

    International Nuclear Information System (INIS)

    Gutierrez Elorza, M.; Pena, J.L.; Rodriguez Vidal, J.; Simon Gomez, J.L.

    1984-01-01

    Some geomorphological criteria, based on the study of erosion surfaces, glacis, terraces and slopes, after a brief discussion of the geomorphological methodology, are here applied in several internal areas of NE. Spain, specially in the Iberian Cordillera. Several episodes of neotectonic activity are recognised within this Cordillera: a more intense one at the base of Villafranchian times, a second one at the Pliocene/Pleistocene transitional levels, and a latent, more sporadic, intraquaternary activity. (author)

  9. Landscapes of human evolution: models and methods of tectonic geomorphology and the reconstruction of hominin landscapes.

    Science.gov (United States)

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

    2011-03-01

    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. Copyright © 2010 Elsevier Ltd. All rights reserved.

  10. Application of airborne gamma-ray spectrometry in soil/regolith mapping and applied geomorphology

    International Nuclear Information System (INIS)

    Wilford, J.R.; Bierwirth, P.N.; Craig, M.A.

    1997-01-01

    Gamma-ray spectrometric surveys are an important source of information for soil, regolith and geomorphological studies, as demonstrated by the interpretation of airborne surveys in Western Australia, central New South Wales and north Queensland. Gamma-rays emitted from the ground surface relate to the primary mineralogy and geochemistry of the bedrock, and the secondary weathered materials. Weathering modifies the distribution and concentration of radioelements from the original bedrock source. Once the radioelement response of bedrock and weathered materials is understood, the gamma-ray data can provide information on geomorphic processes and soil/regolith properties, including their mineralogy, texture, chemistry and style of weathering. This information can contribute significantly to an understanding of the weathering and geomorphic history of a region and, therefore, has the potential to be used in developing more effective land-management strategies and refining geochemical models in support of mineral exploration. Gamma-ray imagery is enhanced when combined with Landsat TM bands and digital elevation models (DEM). This synergy enables geochemical information derived from the gamma-ray data to be interpreted within a geomorphic framework. Draping gamma-ray images over DEMs as 3D landscape perspective views aids interpretation and allows the interpreter to visualise complex relationships between the gamma-ray response and landform features. 44 refs.,1 tab., 11 figs

  11. A Geomorphologically Driven Conditional Assessment for the Study of Urban Stone Decay

    Science.gov (United States)

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

    2017-04-01

    into consideration these limitations by undertaking two conditional assessments, using differing techniques, of wall sections at Fitzroy Presbyterian Church in Belfast. These assessments will be undertaken using a classification system focusing upon percentage of surface alteration. Initially, an assessment was carried out focussing on classifying each block individually. This was then followed by observations in a regular grid of 10x10cm squares across the wall sections. Results suggest that decay features develop beyond the extents of a single stone when situated within a larger built structure, with mortar and blocks providing both interconnectivity and barriers that influence the spread of decay. The results suggest the presence of three wall scale processes; urban microclimatic influencing capillary rise of ground water, architectural features creating a barrier and the passage of moisture through deteriorating mortar. Probe permeametry, GPR and 3D modelling of the wall sections were used to provide support for these findings. For the conservationist, application of a gridded observation approach is time consuming and of little use when deciding upon the remediation of individual blocks. However, in geomorphologically focused studies it facilitates a greater understanding of processes that extend beyond a single block, particularly when considering sites where the development of decay appears to be spatially complex.

  12. Permafrost and climate in Europe: Monitoring and modelling thermal, geomorphological and geotechnical responses

    Science.gov (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

    2009-02-01

    We present a review of the changing state of European permafrost within a spatial zone that includes the continuous high latitude arctic permafrost of Svalbard and the discontinuous high altitude mountain permafrost of Iceland, Fennoscandia and the Alps. The paper focuses on methodological developments and data collection over the last decade or so, including research associated with the continent-scale network of instrumented permafrost boreholes established between 1998 and 2001 under the European Union PACE project. Data indicate recent warming trends, with greatest warming at higher latitudes. Equally important are the impacts of shorter-term extreme climatic events, most immediately reflected in changes in active layer thickness. A large number of complex variables, including altitude, topography, insolation and snow distribution, determine permafrost temperatures. The development of regionally calibrated empirical-statistical models, and physically based process-oriented models, is described, and it is shown that, though more complex and data dependent, process-oriented approaches are better suited to estimating transient effects of climate change in complex mountain topography. Mapping and characterisation of permafrost depth and distribution requires integrated multiple geophysical approaches and recent advances are discussed. We report on recent research into ground ice formation, including ice segregation within bedrock and vein ice formation within ice wedge systems. The potential impacts of climate change on rock weathering, permafrost creep, landslides, rock falls, debris flows and slow mass movements are also discussed. Recent engineering responses to the potentially damaging effects of climate warming are outlined, and risk assessment strategies to minimise geological hazards are described. We conclude that forecasting changes in hazard occurrence, magnitude and frequency is likely to depend on process-based modelling, demanding improved

  13. Geomorphological evidence for ground ice on dwarf planet Ceres

    Science.gov (United States)

    Schmidt, Britney E.; Hughson, Kynan H.G.; Chilton, Heather T.; Scully, Jennifer E. C.; Platz, Thomas; Nathues, Andreas; Sizemore, Hanna; Bland, Michael T.; 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.

    2017-01-01

    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.

  14. Landform elevation suggests ecohydrologic footprints in subsurface geomorphology

    Science.gov (United States)

    Watts, A. C.; Watts, D.; Kaplan, D. A.; Mclaughlin, D. L.; Heffernan, J. B.; Martin, J. B.; Murray, A.; Osborne, T.; Cohen, M. J.; Kobziar, L. N.

    2012-12-01

    Many landscapes exhibit patterns in their arrangement of biota, or in their surface geomorphology as a result of biotic activity. Examples occur around the globe and include northern peatlands, Sahelian savannas, and shallow marine reefs. Such self-organized patterning is strongly suggestive of coupled, reciprocal feedbacks (i.e. locally positive, and distally negative) among biota and their environment. Much research on patterned landscapes has concerned emergent biogeomorphologic surfaces such as those found in peatlands, or the influence of biota on soil formation or transport. Our research concerns ecohydrologic feedbacks hypothesized to produce patterned occurrence of depressions in a subtropical limestone karst landscape. Our findings show strong evidence of self-organized patterning, in the form of overdispersed dissolution basins. Distributions of randomized bedrock elevation measurements on the landscape are bimodal, with means clustered about either higher- or lower-elevation modes. Measurements on the thin mantle of soil overlying this landscape, however, display reduced bimodality and mode separation. These observations indicate abiotic processes in diametric opposition to the biogenic forces which may be responsible for generating landscape pattern. Correlograms show higher spatial autocorrelation among soil measurements compared to bedrock measurements, and measurements of soil-layer thickness show high negative correlation with bedrock elevation. Our results are consistent with predictions of direct ecohydrologic feedbacks that would produce patterned "footprints" directly on bedrock, and of abiotic processes operating to obfuscate this pattern. The study suggests new steps to identify biogeochemical mechanisms for landscape patterning: an "ecological drill" by which plant communities modify geology.

  15. Environment and Economic Activity of the Pestretsy 2 Site Inhabitants on the Mesha River

    Directory of Open Access Journals (Sweden)

    Galimova Madina Sh.

    2016-09-01

    Full Text Available Preliminary results of integrated archaeological and paleo-ecological research in the multilayer site Pestretsy 2 on the Mesha river (Middle Volga region are discussed in the article. As a result of geology and geomorphology studies, it was found that cultural layers of the Bronze and Early Iron Ages occurred in the buried soil complex, which was coated by river fresh deposits formed in 19th–20th centuries. According paleo-geography data, the site was situated on elevated plot in the lake-marsh basin, the basin, which radiocarbon age is about 4 thousand years ago. The site seems to be the remnants of the Late Bronze long-term settlement (at least in excavated part belonging to so called Zaymishche cultural type as shown by stratigraphy, planigraphy and stone artifacts data. The shouldered arrowhead with barbs and triangular stem of the Seyma type found in this layer allows us to refer it to the 18th–16thth centuries. As for the subsequent Ananyino and Azelino cultural layers, they were apparently short-term camps. Numerous faunal remains studied using archaeo-zoological methods, demonstrated animal husbandry practice houses adjoining (so called “forest” type combined with highly developed hunting and seasonal fishing. Use-wear analysis of stone inventory confirms the authors conclusion.

  16. Savannah River Plant environment

    International Nuclear Information System (INIS)

    Dukes, E.K.

    1984-03-01

    On June 20, 1972, the Atomic Energy Commission designated 192,323 acres of land near Aiken, SC, as the nation's first National Environmental Research Park. The designated land surrounds the Department of Energy's Savannah River Plant production complex. The site, which borders the Savannah River for 17 miles, includes swampland, pine forests, abandoned town sites, a large man-made lake for cooling water impoundment, fields, streams, and watersheds. This report is a description of the geological, hydrological, meteorological, and biological characteristics of the Savannah River Plant site and is intended as a source of information for those interested in environmental research at the site. 165 references, 68 figures, 52 tables

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

    Science.gov (United States)

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

    2013-04-01

    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

  18. River history.

    Science.gov (United States)

    Vita-Finzi, Claudio

    2012-05-13

    During the last half century, advances in geomorphology-abetted by conceptual and technical developments in geophysics, geochemistry, remote sensing, geodesy, computing and ecology-have enhanced the potential value of fluvial history for reconstructing erosional and depositional sequences on the Earth and on Mars and for evaluating climatic and tectonic changes, the impact of fluvial processes on human settlement and health, and the problems faced in managing unstable fluvial systems. This journal is © 2012 The Royal Society

  19. Numerical representation of rainfall field in the Yarmouk River Basin

    Science.gov (United States)

    Shentsis, Isabella; Inbar, Nimrod; Magri, Fabien; Rosenthal, Eliyahu

    2017-04-01

    Rainfall is the decisive factors in evaluating the water balance of river basins and aquifers. Accepted methods rely on interpolation and extrapolation of gauged rain to regular grid with high dependence on the density and regularity of network, considering the relief complexity. We propose an alternative method that makes up to those restrictions by taking into account additional physical features of the rain field. The method applies to areas with (i) complex plain- and mountainous topography, which means inhomogeneity of the rainfall field and (ii) non-uniform distribution of a rain gauge network with partial lack of observations. The rain model is implemented in two steps: 1. Study of the rainfall field, based on the climatic data (mean annual precipitation), its description by the function of elevation and other factors, and estimation of model parameters (normalized coefficients of the Taylor series); 2. Estimation of rainfall in each historical year using the available data (less complete and irregular versus climatic data) as well as the a-priori known parameters (by the basic hypothesis on inter-annual stability of the model parameters). The proposed method was developed by Shentsis (1990) for hydrological forecasting in Central Asia and was later adapted to the Lake Kinneret Basin. Here this model (the first step) is applied to the Yarmouk River Basin. The Yarmouk River is the largest tributary of the Jordan River. Its transboundary basin (6,833 sq. km) extends over Syria (5,257 sq.km), Jordan (1,379 sq. km) and Israel (197 sq. km). Altitude varies from 1800 m (and more) to -235 m asl. The total number of rain stations in use is 36 (17 in Syria, 19 in Jordan). There is evidently lack and non-uniform distribution of a rain gauge network in Syria. The Yarmouk Basin was divided into five regions considering typical relationship between mean annual rain and elevation for each region. Generally, the borders of regions correspond to the common topographic

  20. Environmental Assessment and Finding of No Significant Impact: Interim Measures for the Mixed Waste Management Facility Groundwater at the Burial Ground Complex at the Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    N/A

    1999-12-08

    The U. S. Department of Energy (DOE) prepared this environmental assessment (EA) to analyze the potential environmental impacts associated with the proposed interim measures for the Mixed Waste Management Facility (MW) groundwater at the Burial Ground Complex (BGC) at the Savannah River Site (SRS), located near Aiken, South Carolina. DOE proposes to install a small metal sheet pile dam to impound water around and over the BGC groundwater seepline. In addition, a drip irrigation system would be installed. Interim measures will also address the reduction of volatile organic compounds (VOCS) from ''hot-spot'' regions associated with the Southwest Plume Area (SWPA). This action is taken as an interim measure for the MWMF in cooperation with the South Carolina Department of Health and Environmental Control (SCDHEC) to reduce the amount of tritium seeping from the BGC southwest groundwater plume. The proposed action of this EA is being planned and would be implemented concurrent with a groundwater corrective action program under the Resource Conservation and Recovery Act (RCRA). On September 30, 1999, SCDHEC issued a modification to the SRS RCRA Part B permit that adds corrective action requirements for four plumes that are currently emanating from the BGC. One of those plumes is the southwest plume. The RCRA permit requires SRS to submit a corrective action plan (CAP) for the southwest plume by March 2000. The permit requires that the initial phase of the CAP prescribe a remedy that achieves a 70-percent reduction in the annual amount of tritium being released from the southwest plume area to Fourmile Branch, a nearby stream. Approval and actual implementation of the corrective measure in that CAP may take several years. As an interim measure, the actions described in this EA would manage the release of tritium from the southwest plume area until the final actions under the CAP can be implemented. This proposed action is expected to reduce the

  1. The pragmatic roots of American Quaternary geology and geomorphology

    Science.gov (United States)

    Baker, Victor R.

    1996-07-01

    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.

  2. Geomorphology of comet 67P/Churyumov–Gerasimenko

    Science.gov (United States)

    Birch, Samuel P. D.; Tang, Y.; Hayes, A. G.; Kirk, Randolph L.; Bodewitz, D.; Campins, H.; Fernandez, Y.; de Freitas Bart, R.; Kutsop, N. W.; Sierks, H.; Soderblom, J. M.; Squyres, S. W.; Vincent, J.-B.

    2017-01-01

    We present a global geomorphological map of comet 67P/Churyumov–Gerasimenko (67P/C-G) using data acquired by the Rosetta Orbiter’s OSIRIS Narrow Angle Camera. The images used in our study were acquired between 2014 August and 2015 May, before 67P/C-G passed through perihelion. Imagery of the Southern hemisphere was included in our study, allowing us to compare the contrasting hemispheres of 67P/C-G in a single study. Our work also puts into greater context the morphologies studied in previous works, and also the morphologies observed on previously visited cometary nuclei. Relative to other nuclei, 67P/C-G appears most similar to 81P/Wild 2, with a topographically heterogeneous surface dominated by smooth-floored pits. Our mapping describes the landscapes of 67P/C-G when they were first observed by Rosetta, and our map can be used to detect changes in surface morphologies after its perihelion passage. Our mapping reveals strong latitudinal dependences for emplaced units and a highly heterogeneous surface. Layered bedrock units that represent the exposed nucleus of 67P/C-G are dominant at southern latitudes, while topographically smooth, dust covered regions dominate the Northern hemisphere. Equatorial latitudes are dominated by smooth terrain units that show evidence for flow structures. We observe no obvious differences between the comet’s two lobes, with the only longitudinal variations being the Imhotep and Hatmehit basins. These correlations suggest a strong seasonal forcing on the surface evolution of 67P/C-G, where materials are transported from the Southern hemisphere to Northern hemisphere basins over multiple orbital time-scales.

  3. Coastal erosion in Sicily: geomorphologic impact and mitigation (Italy)

    Science.gov (United States)

    Liguori, V.; Manno, G.

    2009-04-01

    The coast of Sicily region stretches about 1400 km, bathing three different seas: the North tract, from Messina to Capo San Vito wash to the Tyrrhenian Sea, the oriental side, from Messina to Capo Passero, wash to the Ionian Sea, and finally the southern side wash to the Mediterranean. Of these, 395 km are made up of beaches and 970 km from rocky shores. The coastal morph-type were analyzed in relation to their evolutionary trend (backspace or advancement of the seaside), can be summarized as follows: a low shores of torrent plain (Messina), low shores with salt (Trapani), low shores beaches edged with dunal systems, subject to backspace, where urbanization has reduced or eliminated the internal sand dunes, shores on marine terraces, with beaches at the foot (Agrigento) and high shores non-affected of real phenomena of backspace, but subject to often dangerous events of detachment and collapse of blocks (high rocky shores). The marine and coastal environment is a complex and articulated, in balance with the Earth's environment, in which live together, but through different dynamics strongly interacting, ecosystems and marine ecosystems typically transition. The increasing density of population concentrated along the shores, the gradual expansion of activities related to the use of marine and coastal resources, are some of the issues that threaten the delicate balance of nature and the sea coast. The sicilian coastal areas most subject to erosion are those in Ragusa shores areas in south-eastern of Sicily, where the critical areas interesting low coastline and high shores. Following the coast, between Capo Peloro and Milazzo (Messina),where the erosion affects the coast with a low of about 23 km. In the coastal between Capo St. Marco and Capo Feto (Trapani) the critical areas interesting the low coastline and, in part erodible bluffs. One of this case is localized in the town of Mazara del Vallo. In general, the phenomenon erosive affects almost all the sicilian

  4. Characterization and quantification of suspended sediment sources to the Manawatu River, New Zealand.

    Science.gov (United States)

    Vale, S S; Fuller, I C; Procter, J N; Basher, L R; Smith, I E

    2016-02-01

    Knowledge of sediment movement throughout a catchment environment is essential due to its influence on the character and form of our landscape relating to agricultural productivity and ecological health. Sediment fingerprinting is a well-used tool for evaluating sediment sources within a fluvial catchment but still faces areas of uncertainty for applications to large catchments that have a complex arrangement of sources. Sediment fingerprinting was applied to the Manawatu River Catchment to differentiate 8 geological and geomorphological sources. The source categories were Mudstone, Hill Subsurface, Hill Surface, Channel Bank, Mountain Range, Gravel Terrace, Loess and Limestone. Geochemical analysis was conducted using XRF and LA-ICP-MS. Geochemical concentrations were analysed using Discriminant Function Analysis and sediment un-mixing models. Two mixing models were used in conjunction with GRG non-linear and Evolutionary optimization methods for comparison. Discriminant Function Analysis required 16 variables to correctly classify 92.6% of sediment sources. Geological explanations were achieved for some of the variables selected, although there is a need for mineralogical information to confirm causes for the geochemical signatures. Consistent source estimates were achieved between models with optimization techniques providing globally optimal solutions for sediment quantification. Sediment sources was attributed primarily to Mudstone, ≈38-46%; followed by the Mountain Range, ≈15-18%; Hill Surface, ≈12-16%; Hill Subsurface, ≈9-11%; Loess, ≈9-15%; Gravel Terrace, ≈0-4%; Channel Bank, ≈0-5%; and Limestone, ≈0%. Sediment source apportionment fits with the conceptual understanding of the catchment which has recognized soft sedimentary mudstone to be highly susceptible to erosion. Inference of the processes responsible for sediment generation can be made for processes where there is a clear relationship with the geomorphology, but is problematic for

  5. Abiotic controls of emergent macrophyte density in a bedrock channel - The Cahaba River, AL (USA)

    Science.gov (United States)

    Vaughn, Ryan S.; Davis, Lisa

    2015-10-01

    Research examining bedrock channels is growing. Despite this, biotic-abiotic interactions remain a topic mostly addressed in alluvial systems. This research identified hydrogeomorphic factors operating at the patch-scale (100-102 m) in bedrock shoals of the Cahaba River (AL) that help determine the distribution of the emergent aquatic macrophyte, Justicia americana. Macrophyte patch density (number of stems/m2) and percent bedrock void surface area (rock surface area/m2 occupied by joints, fractures, and potholes) were measured (n = 24 within two bedrock shoals) using stem counts and underwater photography, respectively. One-dimensional hydrologic modeling (HEC-RAS 4.1.0) was completed for a section within a shoal to examine velocity and channel depth as controlling variables for macrophyte patch density. Results from binary logistic regression analysis identified depth and velocity as good predictors of the presence or absence of Justicia americana within shoal structures (depth p = 0.001, velocity p = 0.007), which is a similar finding to previous research conducted in alluvial systems. Correlation analysis between bedrock surface void area and stem density demonstrated a statistically significant positive correlation (r = 0.665, p = 0.01), elucidating a link between abiotic-biotic processes that may well be unique to bedrock channels. These results suggest that the amount of void space present in bedrock surfaces, in addition to localized depth and velocity, helps control macrophyte patch density in bedrock shoal complexes. The utility of geomorphology in explaining patch-scale habitat heterogeneity in this study highlights geomorphology's potential to help understand macrophyte habitat heterogeneity at the reach scale, while also demonstrating its promise for mapping and understanding habitat heterogeneity at the system scale.

  6. Considering direct and indirect habitat influences on stream biota in eco-geomorphology research to better understand, model, and manage riverine ecosystems

    Science.gov (United States)

    Cienciala, P.; Nelson, A. D.

    2017-12-01

    The field of fluvial eco-geomorphology strives to improve the understanding of interactions between physical and biological processes in running waters. This body of research has greatly contributed to the advancement of integrated river science and management. Arguably, the most popular research themes in eco-geomorphology include hydrogemorphic controls of habitat quality and effects of disturbances such as floods, sediment transport events or sediment accumulation. However, in contrast to the related field of ecology, the distinction between direct and indirect mechanisms which may affect habitat quality and biotic response to disturbance has been poorly explored in eco-geomorphic research. This knowledge gap poses an important challenge for interpretations of field observations and model development. In this research, using the examples of benthic invertebrates and fish, we examine the importance of direct and indirect influences that geomorphic and hydraulic processes may exert on stream biota. We also investigate their implications for modeling of organism-habitat relationships. To achieve our goal, we integrate field and remote sensing data from montane streams in the Pacific Northwest region with habitat models. Preliminary results indicate that indirect hydrogeomorphic influences of stream organisms, such as those mediated by altered availability of food resources, can be as important as direct influences (e.g. physical disturbance). We suggest that these findings may also have important implications for modeling of riverine habitat.

  7. Global Bedload Flux Modeling and Analysis in Large Rivers

    Science.gov (United States)

    Islam, M. T.; Cohen, S.; Syvitski, J. P.

    2017-12-01

    Proper sediment transport quantification has long been an area of interest for both scientists and engineers in the fields of geomorphology, and management of rivers and coastal waters. Bedload flux is important for monitoring water quality and for sustainable development of coastal and marine bioservices. Bedload measurements, especially for large rivers, is extremely scarce across time, and many rivers have never been monitored. Bedload measurements in rivers, is particularly acute in developing countries where changes in sediment yields is high. The paucity of bedload measurements is the result of 1) the nature of the problem (large spatial and temporal uncertainties), and 2) field costs including the time-consuming nature of the measurement procedures (repeated bedform migration tracking, bedload samplers). Here we present a first of its kind methodology for calculating bedload in large global rivers (basins are >1,000 km. Evaluation of model skill is based on 113 bedload measurements. The model predictions are compared with an empirical model developed from the observational dataset in an attempt to evaluate the differences between a physically-based numerical model and a lumped relationship between bedload flux and fluvial and basin parameters (e.g., discharge, drainage area, lithology). The initial study success opens up various applications to global fluvial geomorphology (e.g. including the relationship between suspended sediment (wash load) and bedload). Simulated results with known uncertainties offers a new research product as a valuable resource for the whole scientific community.

  8. Late Holocene lowland fluvial archives and geoarchaeology : Utrecht's case study of Rhine river abandonment under Roman and Medieval settlement

    NARCIS (Netherlands)

    van Dinter, M.; Cohen, K.M.; Hoek, W.Z.; Stouthamer, E.; Jansma, E.; Middelkoop, H.

    2017-01-01

    Fluvial lowlands have become attractive human settling areas all around the world over the last few millennia. Because rivers kept changing their course and networks due to avulsion, the sedimentary sequences in these areas are archives of both fluvial geomorphological and archaeological

  9. Non-linear response of the Golo River system, Corsica, France, to Late Quaternary climatic and sea level variations

    NARCIS (Netherlands)

    Forzoni, A.; Storms, J.E.A.; Reimann, T.; Moreau, J.; Jouet, G.

    2015-01-01

    Disentangling the impact of climatic and sea level variations on fluvio-deltaic stratigraphy is still an outstanding question in sedimentary geology and geomorphology. We used the Golo River system, Corsica, France, as a natural laboratory to investigate the impact of Late Quaternary climate and sea

  10. Morphometric and hydro graphic analysis in the hydro graphic basin of the Salsa river in Paraiba South coast of Brasil

    International Nuclear Information System (INIS)

    Barbosa, M.; Nascimento, J.; Furrier, M.

    2010-01-01

    This paper aims to extend the knowledge on the geomorphology of the river basin Salsa, located in the town of Con de, Paraiba / Brasil. The purpose of the research was to develop thematic maps and get related morphometric data to evaluate possible influences on tectonics. Were used Map data and satellite photos which allowed morphological and clinograficos analyze

  11. Complex Channel Avulsion in the Meghna River Foodplain During the Mid to Late Holocene: The Potential Effect of Tectonic and Co-Seismic Uplift

    Science.gov (United States)

    Dunham, A.; Grall, C.; Mondal, D. R.; Steckler, M. S.; Rajapara, H.; Kumar, B.; Philibosian, B.; Akhter, S. H.; Singhvi, A. K.

    2016-12-01

    Channel migrations and river avulsions in deltaic river systems are mainly driven by differential changes of surface topography, such as the superelevation of channels due to sedimentation. In addition to such autocyclic processes, tectonic events, such as earthquakes, may also lead to avulsions from sudden uplift. The eastern part of the Ganges-Brahmaputra-Meghna Delta (GBMD) is underlain by the blind megathrust of the IndoBurma subduction zone. In this region we investigate a 100 km long sinuous abandoned channel of the Meghna River. Immediately south of the channel, it has been previously shown that the topography is slightly higher than on the rest of the Delta and there is an oxidized Holocene exposure surface. Part of the Titas River flows northward from this area into the abandoned channel belt, opposite of the southward flowing rivers of the delta. We provide results from a detailed investigation of this abandoned channel of the Meghna River using stratigraphic logs of hand-drilled wells, resistivity profiles, sediment analyses and OSL and C14 dating, The OSL ages to be presented constrain the possible date of the event. We employ numerical modeling to evaluate the hypothesis that the co-seismic uplift associated to an earthquake can trigger the channel migration. Our modeling approach aims to estimate the co-seismic uplift associated with potential seismic events using an elastic Coulomb's dislocation model. The geometry fault in our model is estimated using geologic and GPS constraints with standard elastic parameters (Young's modulus = 80 GPa; Poisson's ratio = 0.3). We explored different potential earthquakes geometries that involve the megathrust, a splay fault, or the megathrust terminating in the splay. The magnitude and distribution of co-seismic slip are also varied between a rupture length of 112.5km and 180km along a 225km long fault. We show that any class of models can produce the amount of uplift (1-2 m) necessary for triggering the river

  12. Acid-basic and complexation properties of a sedimentary humic acid. A study on the Barra Bonita reservoir of Tietê river, São Paulo State, Brazil

    Directory of Open Access Journals (Sweden)

    Abate Gilberto

    2001-01-01

    Full Text Available Acid-base and complexation properties of humic acid (HA isolated from a river sediment were studied by potentiometric titration, adopting the discrete site distribution model and the modified Gran functions for data fitting. Six classes of titratable groups were characterized, with pKa values between 2.4 and 10.2. Carboxylic groups accounted for 66% of the total of ionizable sites. The complexing properties were studied with regard to Cu2+, Pb2+, Cd2+ and Zn2+ ions by potentiometric titration using Cu ion selective electrode, or amalgam electrodes (Pb, Cd and Zn. The data treatment by the Scatchard method revealed two binding sites for copper and lead and one binding site for cadmium and zinc. The average stability constants were in the following order: log KHA-Cu > log KHA-Pb > log KHA-Cd @ log KHA-Zn, while the complexing capacity order, Cc, was: Pb > Cu > Cd @ Zn.

  13. Geomorphology of the Namoi alluvial plain, northwestern New South Wales

    International Nuclear Information System (INIS)

    Young, R.W.; Young, A.R.M.; Price, D.M.; Wray, R.A.L.

    2002-01-01

    The Quaternary history of the extensive alluvial plains of the northern part of the Darling River Basin has received little attention, and has generally been assumed to be an analogue of the very detailed history compiled for the Riverine Plain of southeastern Australia. Our study of the Namoi valley, which is a tributary to the upper Darling, shows that this assumption is unfounded. Thermoluminescence dating demonstrates that the oldest palaeochannels of the Namoi River correspond only to the youngest palaeochannels on the Riverine Plain. The thermoluminescence analyses were carried out on the 90-125 μm quartz fraction thermally stimulated by ionizing radiation using the combined additive/regenerative technique. This technique utilises a second glow normalisation procedure that involves re-irradiating each of the quartz sample aliquots and measuring the thermoluminescence induced in the grains. It has ben demonstrated that unlike the streams on the Riverine Plain, the Namoi River has moved progressively away from its buried Tertiary palaeovalley, probably due to declining sediment input from its southern tributaries. In contrast to the streams of the Riverine Plain, the dimensions of the Namoi palaeochannels are indicative of substantially greater discharges until the mid-Holocene. There is also evidence of significant aeolian input throughout the Late Quaternary. The study indicates that the water resources of this increasingly important irrigated region seem to be considerably constrained by the Quaternary heritage of the Namoi valley. Copyright (2002) Geological Society of Australia

  14. Charles River

    Science.gov (United States)

    Information on the efforts of the US EPA, the Commonwealth of Massachusetts, the municipalities within the Charles River Watershed and nongovernmental organizations to improve the water quality of the Charles River.

  15. Coupling legacy geomorphic surface facies to riparian vegetation: Assessing red cedar invasion along the Missouri River downstream of Gavins Point dam, South Dakota

    Science.gov (United States)

    Greene, Samantha L.; Knox, James C.

    2014-01-01

    Floods increase fluvial complexity by eroding established surfaces and creating new alluvial surfaces. As dams regulate channel flow, fluvial complexity often decreases and the hydro-eco-geomorphology of the riparian habitat changes. Along the Missouri River, flow regulation resulted in channel incision of 1-3 m within the study area and disconnected the pre-dam floodplain from the channel. Evidence of fluvial complexity along the pre-dam Missouri River floodplain can be observed through the diverse depositional environments represented by areas of varying soil texture. This study evaluates the role of flow regulation and depositional environment along the Missouri River in the riparian invasion of red cedar downstream of Gavins Point dam, the final dam on the Missouri River. We determine whether invasion began before or after flow regulation, determine patterns of invasion using Bayesian t-tests, and construct a Bayesian multivariate linear model of invaded surfaces. We surveyed 59 plots from 14 riparian cottonwood stands for tree age, plot composition, plot stem density, and soil texture. Red cedars existed along the floodplain prior to regulation, but at a much lower density than today. We found 2 out of 565 red cedars established prior to regulation. Our interpretation of depositional environments shows that the coarser, sandy soils reflect higher energy depositional pre-dam surfaces that were geomorphically active islands and point bars prior to flow regulation and channel incision. The finer, clayey soils represent lower energy depositional pre-dam surfaces, such as swales or oxbow depressions. When determining patterns of invasion for use in a predictive statistical model, we found that red cedar primarily establishes on the higher energy depositional pre-dam surfaces. In addition, as cottonwood age and density decrease, red cedar density tends to increase. Our findings indicate that flow regulation caused hydrogeomorphic changes within the study area that

  16. Climbing walls as multitasking sites of geo(morpho)logical interests: Italian examples from the Western Alps and Sardinia

    Science.gov (United States)

    Bollati, Irene; Fossati, Maria; Panizza, Valeria; Pelfini, Manuela; Zanoletti, Enrico; Zucali, Michele

    2015-04-01

    Geosites and in particular geomorphosites have been recently more and more used as base for educational activities in Earth Sciences and to enhance the geodiversity of a territory. Their attributes acquire a greater value and become especially appreciable when associated with field and outdoor activities. Frequently rock walls represent key sites for geological and gemorphological researches due to the wide outcrops of rocks where mineralogical composition and structures are very evident as well as landforms deriving from the modeling of outcrops surfaces. Where the rock walls are equipped for climbing activities they may be considered open-air laboratories useful to get in touch with the different features of rocks that condition progression on climbing routes. Due to these two aspects, geohistorical importance and educational exemplarity contribute to the increase of the scientific value and, as a consequence, of the global value of these sites as geosites. Geomorphosites from climbing sites allow to realize educational projects with different goals: 1) Recent researches in the Western Italian Alps have been conducted to make a census of climbing rock cliffs along the Ossola Valley (Verbanio-Cusio-Ossola Province, Italy) and to operate a choice of the ones characterized by high educational value (considering easy accessibility, grades for experts and beginners and the good exposition of rock features), representativeness, geohistorical importance, high cultural and socio-economic values, in order to propose an educational project addressed to students of an Italian secondary school aimed at introducing the three great families of rocks (magmatic, metamorphic and sedimentary); 2) The Eclogitic Micaschist Complex of the Austroalpine Domain (Montestrutto climbing wall, Turin Province, Italy) has been investigated in order to i) reconstruct the deformation stages at local scales along the sport climbing wall and the relationships between geological elements and

  17. Application Development: AN Interactive, Non-Technical Perspective of the Geology and Geomorphology of the Ouray Perimeter Tail, CO.

    Science.gov (United States)

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

    2015-12-01

    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

  18. Are calanco landforms similar to river basins?

    Science.gov (United States)

    Caraballo-Arias, N A; Ferro, V

    2017-12-15

    In the past badlands have been often considered as ideal field laboratories for studying landscape evolution because of their geometrical similarity to larger fluvial systems. For a given hydrological process, no scientific proof exists that badlands can be considered a model of river basin prototypes. In this paper the measurements carried out on 45 Sicilian calanchi, a type of badlands that appears as a small-scale hydrographic unit, are used to establish their morphological similarity with river systems whose data are available in the literature. At first the geomorphological similarity is studied by identifying the dimensionless groups, which can assume the same value or a scaled one in a fixed ratio, representing drainage basin shape, stream network and relief properties. Then, for each property, the dimensionless groups are calculated for the investigated calanchi and the river basins and their corresponding scale ratio is evaluated. The applicability of Hack's, Horton's and Melton's laws for establishing similarity criteria is also tested. The developed analysis allows to conclude that a quantitative morphological similarity between calanco landforms and river basins can be established using commonly applied dimensionless groups. In particular, the analysis showed that i) calanchi and river basins have a geometrically similar shape respect to the parameters Rf and Re with a scale factor close to 1, ii) calanchi and river basins are similar respect to the bifurcation and length ratios (λ=1), iii) for the investigated calanchi the Melton number assumes values less than that (0.694) corresponding to the river case and a scale ratio ranging from 0.52 and 0.78 can be used, iv) calanchi and river basins have similar mean relief ratio values (λ=1.13) and v) calanchi present active geomorphic processes and therefore fall in a more juvenile stage with respect to river basins. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Advances in Holocene mountain geomorphology inspired by sediment budget methodology

    Science.gov (United States)

    Slaymaker, Olav; Souch, Catherine; Menounos, Brian; Filippelli, Gabriel

    2003-09-01

    The sediment budget, which links sediment sources to sediment sinks with hydroclimatic and weathering processes mediating the response, is applied to the analysis of sediments in three alpine lakes in British Columbia. We provide two ways of using the sediment budget as an integrating device in the interpretation of mountain geomorphology. These approaches differ in their resolution and ability to budget the major components of the fine-sediment cascade in glaciated environments. Taken together, they provide an integrated index of landscape change over the Holocene. The first example compares the hydroclimatic controls of lake sedimentation for the last 600 years (A.D. 1370-1998) preserved in varved sediments from two of the lake basins. This hydroclimatological approach incorporates contemporary monitoring, air photo analysis, and detailed stratigraphy of sedimentation events within a single varve to infer the timing, sources, and preferred pathways of fine-grained sediments reaching the lake basins. The results indicate that glaciers, hillslope, and channel instability within the major subbasins are the principal sediment sources to the lake basins. Transitory sediment storage of glacially derived sediments within the channels is believed to modulate the episodic and more frequent delivery of sediments from adjacent hillslope and fluvial storage sites and direct routing of glacial rock flour during years of prolonged glacial melt. The second example, relying on the phosphorus geochemistry of sediments in an alpine lake basin, considers the evolution of phosphorus forms (from mineral to occluded and organic fractions) as a function of the soil development, inherent slope instability, and repeated cycles of glaciation and neoglaciation over the Holocene. This geochemical approach demonstrates that both neoglaciation and full glaciation have essentially zeroed the system in such a way that a high proportion of mineral phosphorus remains in the present lake sediments

  20. Geomorphological and Geoelectric Techniques for Kwoi's Multiple Tremor Assessment

    Science.gov (United States)

    Dikedi, P. N.

    2017-12-01

    This work epicentres on geomorphological and geoelectric techniques for multiple tremor assessment in Kwoi, Nigeria. Earth tremor occurrences have been noted by Akpan and Yakubu (2010) within the last 70 years, in nine regions in Nigeria; on September 11,12,20,22, 23 and 24, 2016, additional earth tremors rocked the village of Kwoi eleven times. Houses cracked and collapsed, a rock split and slid and smoke evolved at N9027''5.909''', E800'44.951'', from an altitude of 798m. By employing the Ohmega Meter and Schlumberger configuration, four VES points are sounded for subsurface structure characterisation. Thereafter, a cylindrical steel ring is hammered into the ground at the first point (VES 1) and earth samples are scooped from this location; this procedure is repeated for other points (VES 2, 3 and 4). Winresist, Geo-earth, and Surfer version 12.0.626 software are employed to generate geo-sections, lithology, resistivity profile, Iso resistivity and Isopach maps, of the region. Outcome of results reveal some lithological formations of lateritic topsoil, fractured basement and fresh basement; additionally, results reveal 206.6m, 90.7m, 73.2m and 99.4m fractured basement thicknesses for four points. Scooped samples are transferred to the specimen stage of a Scanning Electron Microscope (SEM). SEM images show rounded inter-granular boundaries—the granular structures act like micro-wheels making the upper crustal mass susceptible to movement at the slightest vibration. Collapsed buildings are sited around VES1 location; samples from VES 1 are the most well fragmented sample owing to multiple microfractures—this result explains why VES 1 has the thickest fractured basement. Abrupt frictional sliding occurs between networks of fault lines; there is a likelihood that friction is most intense at the rock slide site on N9027'21.516'' and E800'44.9993'', VES 1 at N9027'5.819'' and E8005'3.1120'' and smoke sites—holo-centres are suspected below these locations. The

  1. Humans as major geological and geomorphological agents in the Anthropocene: the significance of artificial ground in Great Britain.

    Science.gov (United States)

    Price, Simon J; Ford, Jonathan R; Cooper, Anthony H; Neal, Catherine

    2011-03-13

    Since the first prehistoric people started to dig for stone to make implements, rather than pick up loose material, humans have modified the landscape through excavation of rock and soil, generation of waste and creation of artificial ground. In Great Britain over the past 200 years, people have excavated, moved and built up the equivalent of at least six times the volume of Ben Nevis. It is estimated that the worldwide deliberate annual shift of sediment by human activity is 57,000 Mt (million tonnes) and exceeds that of transport by rivers to the oceans (22,000 Mt) almost by a factor of three. Humans sculpt and transform the landscape through the physical modification of the shape and properties of the ground. As such, humans are geological and geomorphological agents and the dominant factor in landscape evolution through settlement and widespread industrialization and urbanization. The most significant impact of this has been since the onset of the Industrial Revolution in the eighteenth century, coincident with increased release of greenhouse gases to the atmosphere. The anthropogenic sedimentological record, therefore, provides a marker on which to characterize the Anthropocene.

  2. Geomorphologic, stratigraphic and sedimentologic evidences of tectonic activity in Sone-Ganga alluvial tract in Middle Ganga Plain, India

    Science.gov (United States)

    Sahu, Sudarsan; Saha, Dipankar

    2014-08-01

    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.

  3. LAND USE EVOLUTION AND GEOMORPHOLOGICAL UNIT RELATIONSHIP IN RIACHÃO DAS NEVES COUNTY (BA: EFFECTS IN PROTECTED AREAS

    Directory of Open Access Journals (Sweden)

    Rosana Sumiya Gurgel

    2013-07-01

    Full Text Available The appropriation of the natural environment by man establishes strategies of spatial production and organization. This work aims to perform a multitemporal analysis of land use and land cover in the last two decades in Riachão das Neves County, considering the terrain attributes and the adequacy of environmental laws. The methodology adopts remote sensing and GIS techniques and field work. The data processing can be subdivided into the following steps: (a multitemporal analysis of agricultural expansion, (b protected areas mapping, and (c identification of inappropriate use of protected areas. Multitemporal analysis using ALOS-PRISM sensor with high spatial resolution for 2008 and the Landsat imagery from 1988, 1992, 1996, 2000, 2004 and 2008. The classification process was done by visual interpretation and checking of field work. Riachão das Neves has approximately 67% of the natural vegetation. There is an apparent geomorphological control on the production system. In the Depression and Valley areas, the land use is concentrated around the rivers by small farmers, mostly livestock farming, while in the Plateau areas the land use is dominated by large scale mechanized agriculture.

  4. Geomorphological survey and remote sensing analysis: a multidisciplinary approach to reconstruct triggering factors of a DSGSD in Maso Corto (South Tyrol, Italy)

    Science.gov (United States)

    Amato, Gabriele; Fubelli, Giandomenico; Piccin, Gianluca; Chinellato, Giulia; Iasio, Christian; Mosna, David; Morelli, Corrado

    2015-04-01

    Deformation that affects the outcropping metamorphic rocks throughout most part of the slope. Deformation facing southeast is extremely slow, reaching a maximum average speed of 10-15 mm/y. A clearly visible sliding surface, rising further upstream, separates stable bedrock by the deformed layer. Structural-Geomorphological Survey allowed to understand the boundaries of the DSGSD that is located on the east flank of the mountain north of the town, where the adjacent re-incised N-S glacial valley rises the maximum deep. Finally, GPS data measured 34 mm/y as the maximum horizontal velocity value of the rock glaciers in the study area. This low displacement rate let us assume that discontinuous, shallow, hot and thin permafrost may be present in the area. The overall analysis of composite survey suggests that the DSGSD formation may result as consequence of deglaciation, subsequent river incision and presence of tectonic discontinuity surfaces, favorably oriented with respect to the maximum slope, whereas the recent degradation of permafrost, due to post-LGM global warming, might have triggered or increased the velocity of the movement. Keywords: integrated monitoring, permafrost, DSGSD, InSAR, GPS, Rock Glacier, Geomorphological Survey, Alps

  5. Bridging arctic pathways: Integrating hydrology, geomorphology and remote sensing in the north

    Science.gov (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

  6. The elevation and its distribution in geomorphological regions of the European Russia

    Science.gov (United States)

    Kharchenko, S. V.; Ermolaev, O. P.; Mukharamova, S. S.

    2018-01-01

    Spatial differences of elevation were analysed by side of view of geomorphological boundaries on the European Russia territory. Geomorphological pattern of the studied territory was taken from Geomorphological Map of the USSR at scale of 1: 2 500 000. There 2401 fragments for combinations of 58 types of structural landforms and 22 types of sculptural landforms were allocated. The elevation values computed by digital elevation model (cell size - 200 m, number of cells - 322M) based on SRTM (south of 60 nl.) and GDEM 2010 (north of 60 nl.) resampled data. It was founded that some types of structural (16 types) and sculptural (6 types) landforms located in the relatively thin intervals of elevation. Using of elevation above sea level is needed for effective automatic recognizing these landform regions.

  7. Pedogenesis and root development in a complex geomorphologic setting of the Faroe Islands

    DEFF Research Database (Denmark)

    Veihe, Anita; Thers, Mie

    2007-01-01

    Studies of pedogenesis in basaltic soils within the cool, temperate zone were fairly limited. This study looked at pedogenesis and root development in Norðradalur of the Faroe Islands. To a large extent, soil physical and chemical characteristics were determined by sedimentological rather than pe...

  8. Geomorphology, hydrology, and ecology of Great Basin meadow complexes - implications for management and restoration

    Science.gov (United States)

    Jeanne C. Chambers; Jerry R. Miller

    2011-01-01

    This report contains the results of a 6-year project conducted by the U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station and U.S. Environmental Protection Agency, Office of Research and Development on stream incision and meadow ecosystem degradation in the central Great Basin. The project included a coarse-scale assessment of 56 different...

  9. Geographic Information System and Geoportal «River basins of the European Russia»

    Science.gov (United States)

    Yermolaev, O. P.; Mukharamova, S. S.; Maltsev, K. A.; Ivanov, M. A.; Ermolaeva, P. O.; Gayazov, A. I.; Mozzherin, V. V.; Kharchenko, S. V.; Marinina, O. A.; Lisetskii, F. N.

    2018-01-01

    Geographic Information System (GIS) and Geoportal with open access «River basins of the European Russia» were implemented. GIS and Geoportal are based on the map of basins of small rivers of the European Russia with information about natural and anthropogenic characteristics, namely geomorphometry of basins relief; climatic parameters, representing averages, variation, seasonal variation, extreme values of temperature and precipitation; land cover types; soil characteristics; type and subtype of landscape; population density. The GIS includes results of spatial analysis and modelling, in particular, assessment of anthropogenic impact on river basins; evaluation of water runoff and sediment runoff; climatic, geomorphological and landscape zoning for the European part of Russia.

  10. Deglacial history of the Pensacola Mountains, Antarctica from glacial geomorphology and cosmogenic nuclide surface exposure dating

    Science.gov (United States)

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

    2017-02-01

    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.

  11. Ecological significance of riverine gravel bars in regulated river reaches below dams

    Science.gov (United States)

    Ock, G.; Takemon, Y.; Sumi, T.; Kondolf, G. M.

    2012-12-01

    A gravel bar has been recognized as ecologically significant in that they provide simplified habitat with topographical, hydrological and thermo-chemical diversity, while enhancing material exchanges as interfaces laterally between aquatic and terrestrial habitats, and vertically between surface and subsurface waters. During past several decades, regulated rivers below dams have been loss of a number of the geomorphological features due to sediment starvation by upstream dams, accompanied by a subsequent degradation of their ecological functions. Despite a growing concern for gravel bar management recognizing its importance in recovering riverine ecosystem services, the ecological roles of gravel bars have not been assessed enough from the empirical perspectives of habitat diversity and organic matter interactions. In this study, we investigate the 'natural filtering effects' for reducing lentic plankton and contaminants associated with self-purification, and 'physicochemical habitat complexity' of gravel bars, focusing on reach-scaled gravel bars in rivers located in three different countries; First is the Uji River in central Japan, where there has been a loss of gravel bars in the downstream reaches since an upstream dam was constructed in 1965; second is the Tagliamento River in northeast Italy, which shows morphologically intact braided bar channels by natural flooding events and sediment supply; third is the Trinity River in the United States (located in northern California), the site of ongoing restoration efforts for creating new gravel bars through gravel augmentation and channel rehabilitation activities. We traced the downstream changes in particulate organic matter (POM) trophic sources (composed of allochthonous terrestrial inputs, autochthonous instream production and lentic plankton from dam outflows) in order to evaluate the roles of the geomorphological features in tailwater ecosystem food-resources shifting. We calculated suspended POM

  12. GEOMORPHOLOGICAL MAPPING AND GEODIVERSITY: STUDY AT THE MINAS DO CAMAQUÃ GEOSITE PROTECTION AREA (BRAZIL

    Directory of Open Access Journals (Sweden)

    Maurício Mendes Von Ahn

    2017-05-01

    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.

  13. Eten's Coastal Wetland, its geomorphology, water quality and biodiversity

    Science.gov (United States)

    Rojas Carbajal, T. V.; Bartl, K.; Loayza Muro, R.; Abad, J. D.

    2017-12-01

    The Eten's wetland is located in the lower part of the Chancay-Lambayeque River basin at the Peruvian coast. This wetland contains salt and fresh marshes, swamps, lagoons and an estuary which is the result of Reque River's morphodynamics. It provides a great source of totora (Schoenoplectus californicus), a native plant that is used for knitting hats which are an ancient cultural expression in Lambayeque. UNESCO recognized this wetland as one of the ecosystems with the greatest biodiversity along the South Pacific Coast, providing a unique habitat for migratory birds, such as the Peruvian Tern (Sternula lorata). This bird has been classified as endangered in 2005, by the International Union for Conservation of Nature (IUCN). When the area of a wetland is reduced, the resting point function is affected leading to loss in biodiversity due to the habitat conditions are not the same. In 2005, Lambayeque's government established an area of 1377 Ha in order to preserve wetland's ecosystem and Eten's archeological value but wet areas were reduced to 200 Ha. This reduction was promoted by agriculture, urbanization and an inadequate urban waste disposal. The scope of the study is to assess the environmental impacts that affect Eten's wetland. Preliminary results of an assessment with remote sensing indicate that: 1) the Reque River's geomorphic activity was reduced by urbanization, thus, the connection between surface water bodies has been lost, leading the drying out of ponds, 2) the conversion of wet areas to agricultural land, and 3) the natural interaction between the Reque River and the Pacific Ocean was modified due to water control upstream, resulting in a dryer wetland during the last years. Furthermore, the aquatic biodiversity of the wetland was assessed through a biomonitoring method in order to study the impact of water contamination. Four benthic macroinvertebrate Families (Hydrophilidae, Baetidae, Planorbidae and Palaemonidae) were found. The quality of the

  14. Geomorphodiversity derived by a GIS-based geomorphological map: case study the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Demek, J.; Kirchner, Karel; Mackovčin, P.; Slavík, P.

    2011-01-01

    Roč. 55, č. 4 (2011), s. 415-436 ISSN 0372-8854 Institutional research plan: CEZ:AV0Z30860518 Keywords : geomorphodiversity * GIS geomorphological data base * GIS-geomorphological map * Czech Republic Subject RIV: DE - Earth Magnetism, Geodesy, Geography Impact factor: 0.642, year: 2011 http://www.ingentaconnect.com/content/schweiz/zfg/2011/00000055/00000004/art00001?token=004d10697e442f2067217d763b442c233e46533f34687627504541676249266d656cbe1a808f2

  15. Geomorphological Analyses Integrating Geophysical Methods for Hydrocarbon Exploration in the Majaguillar-Corralillo Sector, Cuba

    Directory of Open Access Journals (Sweden)

    María Victoria Pérez-Peña

    2016-10-01

    Full Text Available A more detailed geomorphological study compared to the previous ones was carried out in order to demarcate the potential areas for petroleum exploration. A diagram that integrates geological, geomorphological and geophysical results was prepared. Two structurally surveyed morphological areas (I and II are proposed to address exploration. Area I is recommended to be the one with a higher probability given the presence of rocks of the continental margin at depth, which are the most potential location of petroleum occurrence in Cuba.

  16. National Seabed Mapping Programmes Collaborate to Advance Marine Geomorphological Mapping in Adjoining European Seas

    Science.gov (United States)

    Monteys, X.; Guinan, J.; Green, S.; Gafeira, J.; Dove, D.; Baeten, N. J.; Thorsnes, T.

    2017-12-01

    Marine geomorphological mapping is an effective means of characterising and understanding the seabed and its features with direct relevance to; offshore infrastructure placement, benthic habitat mapping, conservation & policy, marine spatial planning, fisheries management and pure research. Advancements in acoustic survey techniques and data processing methods resulting in the availability of high-resolution marine datasets e.g. multibeam echosounder bathymetry and shallow seismic mean that geological interpretations can be greatly improved by combining with geomorphological maps. Since December 2015, representatives from the national seabed mapping programmes of Norway (MAREANO), Ireland (INFOMAR) and the United Kingdom (MAREMAP) have collaborated and established the MIM geomorphology working group) with the common aim of advancing best practice for geological mapping in their adjoining sea areas in north-west Europe. A recently developed two-part classification system for Seabed Geomorphology (`Morphology' and Geomorphology') has been established as a result of an initiative led by the British Geological Survey (BGS) with contributions from the MIM group (Dove et al. 2016). To support the scheme, existing BGS GIS tools (SIGMA) have been adapted to apply this two-part classification system and here we present on the tools effectiveness in mapping geomorphological features, along with progress in harmonising the classification and feature nomenclature. Recognising that manual mapping of seabed features can be time-consuming and subjective, semi-automated approaches for mapping seabed features and improving mapping efficiency is being developed using Arc-GIS based tools. These methods recognise, spatially delineate and morphologically describe seabed features such as pockmarks (Gafeira et al., 2012) and cold-water coral mounds. Such tools utilise multibeam echosounder data or any other bathymetric dataset (e.g. 3D seismic, Geldof et al., 2014) that can produce a

  17. 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.

    2006-01-01

    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,

  18. Analysis of the development of land use in the Morava River floodplain, with special emphasis on the landscape matrix

    Directory of Open Access Journals (Sweden)

    Kilianová Helena

    2017-03-01

    Full Text Available The results of an analysis of land use development in the Morava River floodplain (Czech Republic using GIS from 1836 to the present, are the subject of this article. The results are based on the analysis of historical maps, using the landscape matrix assessment of the Morava River floodplain. The final analyses were processed from land use maps of the floodplain at a scale of 1 : 25,000 in five time horizons. These maps were compared with the present state of landscape by GIS methods. The study area was assessed according to five geomorphological areas from the northern/higher part to the southern/lower part of floodplain. In 1836 the landscape matrix of the floodplain was composed of meadows and forests. Forest components decreased minimally but the changes are more important. The grassland area (meadows and pastures decreased but arable land, as well as settlements, increased very significantly. In the 1950s the landscape matrix was composed of a mosaic of alluvial forests, meadows and arable land. Currently, the predominant landscape matrix consists of arable land and isolated forest complexes.

  19. Radioactive contamination of aquatic organisms of the Yenisei river in the area affected by the activity of a Russian plutonium complex

    International Nuclear Information System (INIS)

    Bolsunovsky, A.; Sukovaty, A.

    2005-01-01

    The Yenisei River, one of the world's largest rivers, is contaminated with artificial radionuclides released by a Russian facility producing weapons-grade plutonium, which has been in operation for many years. The aim of the study conducted between 1997 and 2003 was to investigate accumulation of artificial radionuclides by aquatic organisms of the Yenisei River and to estimate the exposure dose rates to organisms from various sources. The aquatic plants sampled were of three species: Potamogeton lucens, Fontinalis antipyretica, and Ceratophyllum demersum. The gamma-spectrometric and radiochemical analysis of the samples of aquatic plants for artificial radionuclides has revealed more than 20 long-lived and short-lived radionuclides, including plutonium isotopes. The aquatic animal Phylolimnogammarus viridis and diatoms also contain artificial radionuclides. For most aquatic organisms under study, the dose received from the artificial irradiation is an order of magnitude higher than the dose received from natural irradiation. As Fontinalis antipyretica features the highest capacity to accumulate artificial radionuclides, it accumulates the largest artificial exposure does among the study aquatic organisms (up to 39 μGy/day)

  20. Polygonal tundra geomorphological change in response to warming alters future CO2 and CH4 flux on the Barrow Peninsula.

    Science.gov (United States)

    Lara, Mark J; McGuire, A David; Euskirchen, Eugenie S; Tweedie, Craig E; Hinkel, Kenneth M; Skurikhin, Alexei N; Romanovsky, Vladimir E; Grosse, Guido; Bolton, W Robert; Genet, Helene

    2015-04-01

    The landscape of the Barrow Peninsula in northern Alaska is thought to have formed over centuries to millennia, and is now dominated by ice-wedge polygonal tundra that spans drained thaw-lake basins and interstitial tundra. In nearby tundra regions, studies have identified a rapid increase in thermokarst formation (i.e., pits) over recent decades in response to climate warming, facilitating changes in polygonal tundra geomorphology. We assessed the future impact of 100 years of tundra geomorphic change on peak growing season carbon exchange in response to: (i) landscape succession associated with the thaw-lake cycle; and (ii) low, moderate, and extreme scenarios of thermokarst pit formation (10%, 30%, and 50%) reported for Alaskan arctic tundra sites. We developed a 30 × 30 m resolution tundra geomorphology map (overall accuracy:75%; Kappa:0.69) for our ~1800 km² study area composed of ten classes; drained slope, high center polygon, flat-center polygon, low center polygon, coalescent low center polygon, polygon trough, meadow, ponds, rivers, and lakes, to determine their spatial distribution across the Barrow Peninsula. Land-atmosphere CO2 and CH4 flux data were collected for the summers of 2006-2010 at eighty-two sites near Barrow, across the mapped classes. The developed geomorphic map was used for the regional assessment of carbon flux. Results indicate (i) at present during peak growing season on the Barrow Peninsula, CO2 uptake occurs at -902.3 10(6) gC-CO2 day(-1) (uncertainty using 95% CI is between -438.3 and -1366 10(6) gC-CO2 day(-1)) and CH4 flux at 28.9 10(6) gC-CH4 day(-1) (uncertainty using 95% CI is between 12.9 and 44.9 10(6) gC-CH4 day(-1)), (ii) one century of future landscape change associated with the thaw-lake cycle only slightly alter CO2 and CH4 exchange, while (iii) moderate increases in thermokarst pits would strengthen both CO2 uptake (-166.9 10(6) gC-CO2 day(-1)) and CH4 flux (2.8 10(6) gC-CH4 day(-1)) with geomorphic change from low

  1. Polygonal tundra geomorphological change in response to warming alters future CO2 and CH4 flux on the Barrow Peninsula

    Science.gov (United States)

    Lara, Mark J.; McGuire, A. David; Euskirchen, Eugénie S.; Tweedie, Craig E.; Hinkel, Kenneth M.; Skurikhin, Alexei N.; Romanovsky, Vladimir E.; Grosse, Guido; Bolton, W. Robert; Genet, Helene

    2015-01-01

    The landscape of the Barrow Peninsula in northern Alaska is thought to have formed over centuries to millennia, and is now dominated by ice-wedge polygonal tundra that spans drained thaw-lake basins and interstitial tundra. In nearby tundra regions, studies have identified a rapid increase in thermokarst formation (i.e., pits) over recent decades in response to climate warming, facilitating changes in polygonal tundra geomorphology. We assessed the future impact of 100 years of tundra geomorphic change on peak growing season carbon exchange in response to: (i) landscape succession associated with the thaw-lake cycle; and (ii) low, moderate, and extreme scenarios of thermokarst pit formation (10%, 30%, and 50%) reported for Alaskan arctic tundra sites. We developed a 30 × 30 m resolution tundra geomorphology map (overall accuracy:75%; Kappa:0.69) for our ~1800 km² study area composed of ten classes; drained slope, high center polygon, flat-center polygon, low center polygon, coalescent low center polygon, polygon trough, meadow, ponds, rivers, and lakes, to determine their spatial distribution across the Barrow Peninsula. Land-atmosphere CO2 and CH4 flux data were collected for the summers of 2006–2010 at eighty-two sites near Barrow, across the mapped classes. The developed geomorphic map was used for the regional assessment of carbon flux. Results indicate (i) at present during peak growing season on the Barrow Peninsula, CO2 uptake occurs at -902.3 106gC-CO2 day−1(uncertainty using 95% CI is between −438.3 and −1366 106gC-CO2 day−1) and CH4 flux at 28.9 106gC-CH4 day−1(uncertainty using 95% CI is between 12.9 and 44.9 106gC-CH4 day−1), (ii) one century of future landscape change associated with the thaw-lake cycle only slightly alter CO2 and CH4 exchange, while (iii) moderate increases in thermokarst pits would strengthen both CO2uptake (−166.9 106gC-CO2 day−1) and CH4 flux (2.8 106gC-CH4 day−1) with geomorphic change from

  2. From hydro-geomorphological mapping to sediment transfer evaluation in the Upper Guil Catchment (Queyras, French Alps)

    Science.gov (United States)

    Lissak, Candide; Fort, Monique; Arnaud-Fassetta, Gilles; Mathieu, Alexandre; Malet, Jean-Philippe; Carlier, Benoit; Betard, François; Cossart, Etienne; Madelin, Malika; Viel, Vincent; Charney, Bérengère; Bletterie, Xavier

    2014-05-01

    The Guil River catchment (Queyras, Southern French Alps) is prone to hydro-geomorphic hazards related to catastrophic floods, with an amplification of their impacts due to strong hillslope-channel connectivity such as in 1957 (> R.I. 100 yr), and more recently in 2000 (R.I. 30 yr). In both cases, the rainfall intensity, aggravated by pre-existing saturated soils, explained the immediate response of the fluvial system and the subsequent destabilisation of slopes. This resulted in serious damages to infrastructure and buildings in the valley bottom, mostly along some specific reaches and confluences with debris flow prone tributaries. After each event, new protective structures are built. One of the purposes of this study, undertaken in the frame of the SAMCO (ANR) project, was to understand the hydro-geomorphological functioning of this upper Alpine catchment in a context of hazards mitigation and sustainable management of sediment yield, transfer and deposition. To determine the main sediment storages that could be mobilised during the next major hydro-meteorological events, the first step of our study consists in the identification and characterisation of areas that play a role into the sediment transfer processing. From environmental characteristics (channel geometric, vegetation cover…) and anthropogenic factors (hydraulic infrastructures, urban development…), a semi-automatic method provides a typology of contribution areas with sediment storages sensitive to erosion, or areas that will be prone to deposition of sediments during the next flooding event. The second step of the study is focused on the sediment storages with their characterisation and connectivity to the trunk channel. Taking into account the entire catchment and including the torrential system, this phase analyses the sedimentary transfers from the identification and classification of sediment storages to the evaluation of the degree of connectivity with the main or secondary channels. The

  3. THE CONFLUENCE RATIO OF THE TRANSYLVANIAN BASIN RIVERS

    Directory of Open Access Journals (Sweden)

    ROŞIAN GH.

    2014-03-01

    Full Text Available There are many possibilities to assess the hydrological and geomorphological evolution of a territory. Among them, one remarks the confluence ratio of the rivers belonging to different catchment areas. The values of this indicator may provide information regarding the stage of evolution of the fluvial landforms in the Transylvanian Basin. Also, the values may serve for the calculation of other parameters of catchment areas like: the degree of finishing of the drainage basin for its corresponding order, the density of river segments within a catchment area etc. To calculate the confluence ratio, 35 catchment areas of different orders have been selected. The confluence ratio varies between 3.04 and 6.07. The large range of values demonstrates the existence of a heterogeneous lithology and of morphological and hydrographical contrasts from one catchment area to the other. The existence of values above 5, correlated also with observations in the field, reveals an accelerated dynamics of the geomorphological processes in those catchment areas. This dynamic is mainly supported by the high landform fragmentation due to the first order rivers. In contrast, the catchment areas that have a confluence ratio below 5 are in a more advanced stage of evolution with stable slopes, unable to initiate new first order river segments.

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

    Science.gov (United States)

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

    1996-06-01

    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

  5. A geomorphologist's dream come true: synoptic high resolution river bathymetry with the latest generation of airborne dual wavelength lidar

    Science.gov (United States)

    Lague, Dimitri; Launeau, Patrick; Michon, Cyril; Gouraud, Emmanuel; Juge, Cyril; Gentile, William; Hubert-Moy, Laurence; Crave, Alain

    2016-04-01

    Airborne, terrestrial lidar and Structure From Motion have dramatically changed our approach of geomorphology, from low density/precision data, to a wealth of data with a precision adequate to actually measure topographic change across multiple scales, and its relation to vegetation. Yet, an important limitation in the context of fluvial geomorphology has been the inability of these techniques to penetrate water due to the use of NIR laser wavelengths or to the complexity of accounting for water refraction in SFM. Coastal bathymetric systems using a green lidar can penetrate clear water up to 50 m but have a resolution too coarse and deployment costs that are prohibitive for fluvial research and management. After early prototypes of narrow aperture green lidar (e.g., EEARL NASA), major lidar manufacturer are now releasing dual wavelength laser system that offer water penetration consistent with shallow fluvial bathymetry at very high resolution (> 10 pts/m²) and deployment costs that makes the technology, finally accessible. This offers unique opportunities to obtain synoptic high resolution, high precision data for academic research as well as for fluvial environment management (flood risk mapping, navigability,…). In this presentation, we report on the deployment of the latest generation Teledyne-Optech Titan dual-wavelength lidar (1064 nm + 532 nm) owned by the University of Nantes and Rennes. The instrument has been deployed over several fluvial and lacustrine environments in France. We present results and recommendation on how to optimize the bathymetric cover as a function of aerial and aquatic vegetation cover and the hydrology regime of the river. In the surveyed rivers, the penetration depth varies from 0.5 to 4 m with discrete echoes (i.e., onboard detection), heavily impacted by water clarity and bottom reflectance. Simple post-processing of the full waveform record allows to recover an additional 20 % depth. As for other lidar techniques, the main

  6. Active tectonics in the Mygdonia basin (northern Greece): a combined seismological and remote-sensed geomorphology approach

    Science.gov (United States)

    Gkarlaouni, Charikleia; Andreani, Louis; Pennos, Chris; Gloaguen, Richard; Papadimitriou, Eleftheria; Kilias, Adamantios; Michail, Maria

    2014-05-01

    along the southern flank of the Mygdonia graben. Observed differences may be related to a diachronic evolution. River profiles crossing the Thessaloniki-Gerakarou fault system (TGFS) south of the Mygdonia basin display anomalies such as knickpoints or convex segments. These anomalies reflect significant changes in river base-levels possibly triggered by uplift/subsidence processes. We also computed the normalized steepness index (ksn) for concave segments in rivers. We observe an increase of ksn values towards the south while the lithology remains almost constant. These changes in ksn values may be thus related to an increase in deformation rates along the southern TGFS. Our geomorphic analysis also highlighted several flat paleo-surfaces located on top of main ranges at elevations comprised between 300 and 450m above the basin infill. Finally, we produced thematic maps combining present-day seismicity, historical earthquakes and geomorphic features derived from DEM. The combined use of both seismology and remote-sensed geomorphology allowed us to better understand the at-depth and surface expressions of active structures within the Mygdonia basin. It also provided further insights into the tectonic evolution of the study area. This project is funded by the German Academic Exchange Service (DAAD) and the Greek State Scholarschips Foundation (IKY) under the IKYDA initiative.

  7. Geomorphologic analysis in the assessment of slope susceptibility in reservoirs. Case studies of the Guadalquivir basin, Spain; Analisis geomorfologico para la determinacion de la susceptibilidad en las laderas de los embalses. Aplicacion a los embalses de Danador, Guadalmena y Tranco de Beas (cuenca del Guadalquivir, Espana)

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez Garcia, P.; Garcia de Domingo, A.; Alameda Revalderia, J.

    2008-07-01

    Knowledge of conditioning factors regarding slope stability in reservoirs requires a detailed background study of the main dynamic processes acting in the surroundings of the dam. In this sense, geomorphologic mapping provides excellent results in the determination of unstable slopes and their level of susceptibility. This essay analyzes the geological and geomorphologic characteristics in the surroundings of Danador, Guadalmena and Tranco de Beas reservoirs, all of them located within the basin of the Guadalquivir river. A selected area, approximately 1,500 meters wide, around each reservoir was mapped, and a detailed geological and geomorphologic database was obtained for each one in which the surficial formations were represented. The analysis of the main geomorphologic processes, in terms of location, characteristics and assessed level of activity, has allowed for the delimitation of those areas that could suffer changes in their safety level in the short term, thus affecting the reservoir itself. The most important ones are those derived from slope movements (rock falls, landslides), slope erosion (gullies and rills) and karstic processes (subsidence and collapses). (Author)

  8. River predisposition to ice jams: a simplified geospatial model

    Directory of Open Access Journals (Sweden)

    S. De Munck

    2017-07-01

    Full Text Available Floods resulting from river ice jams pose a great risk to many riverside municipalities in Canada. The location of an ice jam is mainly influenced by channel morphology. The goal of this work was therefore to develop a simplified geospatial model to estimate the predisposition of a river channel to ice jams. Rather than predicting the timing of river ice breakup, the main question here was to predict where the broken ice is susceptible to jam based on the river's geomorphological characteristics. Thus, six parameters referred to potential causes for ice jams in the literature were initially selected: presence of an island, narrowing of the channel, high sinuosity, presence of a bridge, confluence of rivers, and slope break. A GIS-based tool was used to generate the aforementioned factors over regular-spaced segments along the entire channel using available geospatial data. An ice jam predisposition index (IJPI was calculated by combining the weighted optimal factors. Three Canadian rivers (province of Québec were chosen as test sites. The resulting maps were assessed from historical observations and local knowledge. Results show that 77 % of the observed ice jam sites on record occurred in river sections that the model considered as having high or medium predisposition. This leaves 23 % of false negative errors (missed occurrence. Between 7 and 11 % of the highly predisposed river sections did not have an ice jam on record (false-positive cases. Results, limitations, and potential improvements are discussed.

  9. Water quality assessment of the Sinos River, Southern Brazil.

    Science.gov (United States)

    Blume, K K; Macedo, J C; Meneguzzi, A; Silva, L B; Quevedo, D M; Rodrigues, M A S

    2010-12-01

    The Sinos River basin is located Northeast of the state of Rio Grande do Sul (29º 20' to 30º 10' S and 50º 15' to 51º20'W), Southern Brazil, covering two geomorphologic provinces: the Southern plateau and central depression. It is part of the Guaíba basin and has an area of approximately 800 km², encompassing 32 municipalities. The objective of this study was to monitor water quality in the Sinos River, the largest river in this basin. Water samples were collected at four selected sites in the Sinos River, and the following parameters were analysed: pH, dissolved oxygen, biochemical oxygen demand (BOD₅), turbidity, fecal coliforms, total dissolved solids, temperature, nitrate, nitrite, phosphorous, chromium, lead, aluminum, zinc, iron, and copper. The results were analysed based on Resolution No. 357/2005 of the Brazilian National Environmental Council (CONAMA) regarding regulatory limits for residues in water. A second analysis was performed based on a water quality index (WQI) used by the Sinos River Basin Management Committee (COMITESINOS). Poor water quality in the Sinos River presents a worrying scenario for the region, since this river is the main source of water supply for the urban core. Health conditions found in the Sinos River, mainly in its lower reaches, are worrying and a strong indicator of human activities on the basin.

  10. Water quality assessment of the Sinos River, Southern Brazil

    Directory of Open Access Journals (Sweden)

    KK. Blume

    Full Text Available The Sinos River basin is located Northeast of the state of Rio Grande do Sul (29º 20' to 30º 10' S and 50º 15' to 51º20'W, Southern Brazil, covering two geomorphologic provinces: the Southern plateau and central depression. It is part of the Guaíba basin and has an area of approximately 800 km², encompassing 32 municipalities. The objective of this study was to monitor water quality in the Sinos River, the largest river in this basin. Water samples were collected at four selected sites in the Sinos River, and the following parameters were analysed: pH, dissolved oxygen, biochemical oxygen demand (BOD5, turbidity, fecal coliforms, total dissolved solids, temperature, nitrate, nitrite, phosphorous, chromium, lead, aluminum, zinc, iron, and copper. The results were analysed based on Resolution No. 357/2005 of the Brazilian National Environmental Council (CONAMA regarding regulatory limits for residues in water. A second analysis was performed based on a water quality index (WQI used by the Sinos River Basin Management Committee (COMITESINOS. Poor water quality in the Sinos River presents a worrying scenario for the region, since this river is the main source of water supply for the urban core. Health conditions found in the Sinos River, mainly in its lower reaches, are worrying and a strong indicator of human activities on the basin.

  11. Cytogenetic characterization of Hoplias malabaricus (Bloch, 1794 from the Ctalamochita River (Córdoba, Argentina: first evidence for southernmost populations of this species complex and comments on its biogeography

    Directory of Open Access Journals (Sweden)

    Diego Javier Grassi

    2017-01-01

    Full Text Available Hoplias malabaricus (Bloch, 1794, a predatory freshwater fish with a wide distribution throughout South America, represents a species complex with seven well characterized karyomorphs at the cytogenetic level. Although this species has been extensively studied in several Brazilian basins, data are still scarce for hydrographic systems from other South American countries. This study aims to characterize cytogenetically the Hoplias malabaricus populations from the Argentinean Central Region, close to the southernmost distribution of this species complex. A total of 32 specimens from the Ctalamochita River, a tributary of Lower Paraná Basin located in the province of Córdoba, were analyzed using cytogenetic techniques (Giemsa staining, C- and Ag-NOR banding and fluorescent in situ hybridization with 18S rDNA. All the specimens showed diploid number 2n=42, chromosomic formula 22m + 20sm and absence of sexual chromosomes. Thus, the analyzed populations belong to the karyomorph named A. These populations showed a remarkable degree of divergence in their cytogenetic traits such as karyotypic formula, C-banding, NORs and 18S rDNA patterns for Hoplias malabaricus from other populations bearing the same karyomorph in the Middle and Upper Paraná Basin. These findings are consistent with molecular data from a recent study (where specimens collected in the present work were included, which indicate a closer phylogenetic relationship of Hoplias malabaricus populations from the Ctalamochita River with those from the Uruguay basin and the coastal regions of South Brazil than with populations from the Middle and Upper Paraná Basin. Overall, these pieces of evidence highlight the distinctive features of Hoplias malabaricus from the Ctalamochita River, and also reveal a complex history of dispersion of these populations. The present work is the first to provide cytogenetic information and include some phylogeographic aspects of Hoplias malabaricus populations

  12. Expert-driven semi-automated geomorphological mapping for a mountainaous area using a laser DTM

    NARCIS (Netherlands)

    van Asselen, S.; Seijmonsbergen, A.C.

    2006-01-01

    n this paper a semi-automated method is presented to recognize and spatially delineate geomorphological units in mountainous forested ecosystems, using statistical information extracted from a 1-m resolution laser digital elevation dataset. The method was applied to a mountainous area in Austria.

  13. Quantitative geomorphology with geographical information systems (GIS) for evolving societies and science

    Science.gov (United States)

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

    2016-05-01

    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.

  14. Better Visualisation of Air-borne Laser Scanning for geomorphological and archaeological interpretation

    DEFF Research Database (Denmark)

    Ljungberg, Thomas; Scott, D; Kristiansen, Søren Munch

    Digital elevation models derived from high-precision Air-borne Laser Scanning (ALS or LiDAR) point clouds are becoming increasingly available throughout the world. These elevation models presents a very valuable tool for locating and interpreting geomorphological as well as archaeological features...

  15. The dilemma of dykes - Risk and opportunities in a simulation of geomorphology at mega timescales

    NARCIS (Netherlands)

    Hagen - Zanker, A.H.; de Vries, Ies; Hartholt, H.

    2007-01-01

    SimDelta dynamically simulates the geomorphology of the ‘Dutch Delta’ at a mega time scale. Scientifically a success, the model has scope for development as a game. Through challenging game play policy makers, spatial planners and students learn about the dilemmas posed by short and long term

  16. Geomorphological research of large-scale slope instability at Machu Picchu, Peru

    Czech Academy of Sciences Publication Activity Database

    Vilímek, V.; Zvelebil, J.; Klimeš, Jan; Patzelt, Z.; Astete, F.V.; Kachlík, F.; Hartvich, Filip

    2007-01-01

    Roč. 89, č. 3-4 (2007), s. 241-257 ISSN 0169-555X Institutional research plan: CEZ:AV0Z30460519 Keywords : natural hazard * Machu Picchu * landslides Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.854, year: 2007 www.elsevier.com/locate/geomorphology

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

    NARCIS (Netherlands)

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

    2013-01-01

    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

  18. Fire and water: volcanology, geomorphology, and hydrogeology of the Cascade Range, central Oregon

    Science.gov (United States)

    Katharine V. Cashman; Natalia I. Deligne; Marshall W. Gannett; Gordon E. Grant; Anne. Jefferson

    2009-01-01

    This field trip guide explores the interactions among the geologic evolution, hydrology, and fluvial geomorphology of the central Oregon Cascade Range. Key topics include the geologic control of hydrologic regimes on both the wet and dry sides of the Cascade Range crest, groundwater dynamics and interaction between surface and groundwater in young volcanic arcs, and...

  19. Learning Geomorphology Using Aerial Photography in a Web-Facilitated Class

    Science.gov (United States)

    Palmer, R. Evan

    2013-01-01

    General education students taking freshman-level physical geography and geomorphology classes at Arizona State University completed an online laboratory whose main tool was Google Earth. Early in the semester, oblique and planimetric views introduced students to a few volcanic, tectonic, glacial, karst, and coastal landforms. Semi-quantitative…

  20. A Coastal Environment Field and Laboratory Activity for an Undergraduate Geomorphology Course

    Science.gov (United States)

    Ellis, Jean T.; Rindfleisch, Paul R.

    2006-01-01

    A field and laboratory exercise for an undergraduate geomorphology class is described that focuses on the beach. The project requires one day of fieldwork and two laboratory sessions. In the field, students measure water surface fluctuations (waves) with a pressure sensor, survey beach profiles, collect sediment samples, and observe the beach…

  1. An Evaluation of the Effectiveness of Stereo Slides in Teaching Geomorphology.

    Science.gov (United States)

    Giardino, John R.; Thornhill, Ashton G.

    1984-01-01

    Provides information about producing stereo slides and their use in the classroom. Describes an evaluation of the teaching effectiveness of stereo slides using two groups of 30 randomly selected students from introductory geomorphology. Results from a pretest/postttest measure show that stereo slides significantly improved understanding. (JM)

  2. Geography and sciences for field work in geomorphology: Contributions in environmental education system

    International Nuclear Information System (INIS)

    Santos, C.

    2010-01-01

    This conference is about the possibility of a field study in Jaragua Peak in the metropolitan region of Sao Paulo, between the cities of Sao Paulo and Osasco. The main objective is to offer a new way of seeing the environment and the geomorphology as well as the best use at school

  3. 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.

    2006-01-01

    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

  4. Geomorphologically effective floods from moraine-dammed lakes in the Cordillera Blanca, Peru

    Science.gov (United States)

    Emmer, Adam

    2017-12-01

    Outburst floods originating in moraine-dammed lakes represent a significant geomorphological process as well as a specific type of threat for local communities in the Cordillera Blanca, Peru (8.5°-10° S; 77°-78° W). An exceptional concentration of catastrophic floods has been reported from the Cordillera Blanca in the first half of 20th Century (1930s-1950s), leading to thousands of fatalities. The main objective of this paper is to provide a revised and comprehensive overview of geomorphologically effective floods in the area of interest, using various documentary data sources, verified by analysis of remotely sensed images (1948-2013) and enhanced by original field data. Verified events (n = 28; 4 not mentioned before) are analysed from the perspective of spatiotemporal distribution, pre-flood conditions, causes, mechanisms and geomorphological impacts as well as socioeconomical consequences, revealing certain patterns and similar features. GLOFs are further classified according to their magnitude: 5 extreme events, 8 major events and 15 minor events are distinguished, referring to the quantified geomorphological and socioeconomical impacts. Selected moraine dams and flood deposits are dated using lichenometric dating. Special attention is given to moraine dam breaches - the most frequent type of water release with the most significant consequences. Selected major events and their consequences are studied in detail in a separate section. Finally, a general schematic model of lake formation, growth and post-flood evolution reflecting initial topographical setting and glacier retreat is introduced and the utilization of the obtained results is outlined.

  5. 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.

    2010-01-01

    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

  6. Constraints on the geomorphological evolution of the nested summit craters of Láscar volcano from high spatio-temporal resolution TerraSAR-X interferometry

    Science.gov (United States)

    Richter, Nicole; Salzer, Jacqueline Tema; de Zeeuw-van Dalfsen, Elske; Perissin, Daniele; Walter, Thomas R.

    2018-03-01

    Small-scale geomorphological changes that are associated with the formation, development, and activity of volcanic craters and eruptive vents are often challenging to characterize, as they may occur slowly over time, can be spatially localized, and difficult, or dangerous, to access. Using high-spatial and high-temporal resolution synthetic aperture radar (SAR) imagery collected by the German TerraSAR-X (TSX) satellite in SpotLight mode in combination with precise topographic data as derived from Pléiades-1A satellite data, we investigate the surface deformation within the nested summit crater system of Láscar volcano, Chile, the most active volcano of the central Andes. Our aim is to better understand the structural evolution of the three craters that comprise this system, to assess their physical state and dynamic behavior, and to link this to eruptive activity and associated hazards. Using multi-temporal SAR interferometry (MT-InSAR) from ascending and descending orbital geometries, we retrieve the vertical and east-west components of the displacement field. This time series indicates constant rates of subsidence and asymmetric horizontal displacements of all summit craters between June 2012 and July 2014, as well as between January 2015 and March 2017. The vertical and horizontal movements that we observe in the central crater are particularly complex and cannot be explained by any single crater formation mechanism; rather, we suggest that short-term activities superimposed on a combination of ongoing crater evolution processes, including gravitational slumping, cooling and compaction of eruption products, as well as possible piston-like subsidence, are responsible for the small-scale geomorphological changes apparent in our data. Our results demonstrate how high-temporal resolution synthetic aperture radar interferometry (InSAR) time series can add constraints on the geomorphological evolution and structural dynamics of active crater and vent systems at

  7. Karst geomorphology and hydrology at the Campania - Basilicata border (southern Apennines of Italy)

    Science.gov (United States)

    Farfan Gonzalez, H.; Parise, M.

    2009-04-01

    This paper describes the main karst geomorphological and hydrological features of the area at the boundary between the Campania and Basilicata regions, in the southern Apennines of Italy. Even not far from the most important karst area of southern Italy (the Alburni Massif, hosting hundreds of caves, with very complex subterranean systems that have been extensively explored in the last 50 years), this sector has never been object of detailed karstic studies. Geologically, it shows a carbonate bedrock consisting of Cretaceous limestones and dolomites, in tectonic contact with terrigenous deposits of Miocene age. The territory is an active seismogenic zone, as testified by the November 23, 1980, earthquake that hit this part of southern Italy with a 6.8 magnitude, causing over 2,700 victims and destroying several small towns in the two regions. In 2007, within the framework of joint projects between the Italian Speleological Society (SSI) and the Cuban Speleological Society (SEC), a scientific and speleological expedition was carried out in a sector of this area. The efforts produced during the expedition, and in the preceeding phases as well, resulted in discovery, survey and documentation of 62 caves, and in supporting the progresses of the exploration activities in the main karst system in the area, a complex of two caves that reach a maximum depth of 123 meters and an overall length of 1,8 km. At the surface, a variety of karst landforms is recognizable. The main carbonate ridges show several orders of palaeosurfaces, located at different heights above sea level. Bounded by fault lines or fault line scarps, they present variable extension, the highest surfaces showing a much better continuity. On the Campanian side, several sinkholes are also present, some of which opened in the aftermath of the 1980 earthquake. The same event caused in Basilicata the formation of several caves of structural origin, controlled in their development by tectonics and extremely

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

    Science.gov (United States)

    Buzjak, Nenad; Bocic, Neven; Pahernik, Mladen

    2014-05-01

    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

  9. Landscape controls and vertical variability of soil organic carbon storage in permafrost-affected soils of the Lena River Delta

    DEFF Research Database (Denmark)

    Siewert, Matthias Benjamin; Hugelius, Gustaf; Heim, Birgit

    2016-01-01

    To project the future development of the soil organic carbon (SOC) storage in permafrost environments, the spatial and vertical distribution of key soil properties and their landscape controls needs to be understood. This article reports findings from the Arctic Lena River Delta where we sampled 50...... in the permafrost. The major geomorphological units of a subregion of the Lena River Delta were mapped with a land form classification using a data-fusion approach of optical satellite imagery and digital elevation data to upscale SOC storage. Landscape mean SOC storage is estimated to 19.2 ± 2.0 kg C m− 2. Our...... results show that the geomorphological setting explains more soil variability than soil taxonomy classes or vegetation cover. The soils from the oldest, Pleistocene aged, unit of the delta store the highest amount of SOC per m2 followed by the Holocene river terrace. The Pleistocene terrace affected...

  10. BANK STABILIZATION, SHORELINE LAND-USE, AND THE DISTRIBUTION OF LARGE WOODY DEBRIS IN A REGULATED REACH OF THE UPPER MISSOURI RIVER, NORTH DAKOTA, USA

    Science.gov (United States)

    Large woody debris (LWD) is an important component of ecosystem function in floodplain rivers. We examined the effects on LWD distribution of shoreline land use, bank stabilization, local channel geomorphology, and distance from the dam in the Garrison Reach, a regulated reach of...

  11. Geologic, geomorphologic evaluation and analysis of the degree of susceptibility to floods and torrential avenues in the sub-basin of the Cambia Ravine, Municipalities of Anserma, Risaralda and San Jose, (Caldas)

    International Nuclear Information System (INIS)

    Franco H, Mariana; Guapacha, Ana Maria

    2002-01-01

    The Cambia sub-basin is located in Colombia's western cordillera and has an extension of 89,39 k m2, it is affected by the Rome ral Fault System. The lithology of the area consists of cretaceous rocks of the Diabasic B/R's Formation which is the basement of the area, this unit is overlaid by the tertiary unit of alluvial terraces of the C.c. River and the quaternary units of the: Plan de Aeromonas Mud flow, and the recent alluvial deposits. This thesis aimed to know the geology, geomorphology, mass movements and the susceptibility to river flood susceptibility. The hazard analysis was based on the cartographic updating and analysis of the geology, fluvial geomorphology, the mass movements' characterization, the flow was calculated via the Swat software based on precipitation data and later on the delimitation of the flooded areas was accomplished by using the Heck-Gar's software plus a qualitative analysis of the sub-basin. The main conclusions of this study are: There is flood hazard within this sub-basin, The flooded hazard areas were delimited for the return periods calculated and these areas require an adequate management. This thesis intended to evaluate the susceptibility analysis but the hazard analysis was accomplished. The methodology used is highly recommended for areas, which have the necessary specification to apply it

  12. Using geomorphological variables to predict the spatial distribution of plant species in agricultural drainage networks.

    Science.gov (United States)

    Rudi, Gabrielle; Bailly, Jean-Stéphane; Vinatier, Fabrice

    2018-01-01

    To optimize ecosystem services provided by agricultural drainage networks (ditches) in headwater catchments, we need to manage the spatial distribution of plant species living in these networks. Geomorphological variables have been shown to be important predictors of plant distribution in other ecosystems because they control the water regime, the sediment deposition rates and the sun exposure in the ditches. Whether such variables may be used to predict plant distribution in agricultural drainage networks is unknown. We collected presence and absence data for 10 herbaceous plant species in a subset of a network of drainage ditches (35 km long) within a Mediterranean agricultural catchment. We simulated their spatial distribution with GLM and Maxent model using geomorphological variables and distance to natural lands and roads. Models were validated using k-fold cross-validation. We then compared the mean Area Under the Curve (AUC) values obtained for each model and other metrics issued from the confusion matrices between observed and predicted variables. Based on the results of all metrics, the models were efficient at predicting the distribution of seven species out of ten, confirming the relevance of geomorphological variables and distance to natural lands and roads to explain the occurrence of plant species in this Mediterranean catchment. In particular, the importance of the landscape geomorphological variables, ie the importance of the geomorphological features encompassing a broad environment around the ditch, has been highlighted. This suggests that agro-ecological measures for managing ecosystem services provided by ditch plants should focus on the control of the hydrological and sedimentological connectivity at the catchment scale. For example, the density of the ditch network could be modified or the spatial distribution of vegetative filter strips used for sediment trapping could be optimized. In addition, the vegetative filter strips could constitute

  13. Beach Geomorphology and Kemp's Ridley (Lepidochelys kempii) Nest Site Selection along Padre Island, Texas, USA

    Science.gov (United States)

    Culver, M.; Gibeaut, J. C.; Shaver, D. J.; Tissot, P.; Starek, M. J.

    2017-12-01

    The Kemp's ridley sea turtle (Lepidochelys kempii) is the most endangered sea turtle in the world, largely due to the limited geographic range of its nesting habitat. In the U.S., the majority of nesting occurs along Padre Island National Seashore (PAIS) in Texas. There has been limited research regarding the connection between beach geomorphology and Kemp's ridley nesting patterns, but studies concerning other sea turtle species suggest that certain beach geomorphology variables, such as beach slope and width, influence nest site selection. This research investigates terrestrial habitat variability of the Kemp's ridley sea turtle and quantifies the connection between beach geomorphology and Kemp's ridley nest site selection on PAIS and South Padre Island, Texas. Airborne topographic lidar data collected annually along the Texas coast from 2009 through 2012 was utilized to extract beach geomorphology characteristics, such as beach slope and width, dune height, and surface roughness, among others. The coordinates of observed Kemp's ridley nests from corresponding years were integrated with the aforementioned data in statistical models, which analyzed the influence of both general trends in geomorphology and individual morphologic variables on nest site selection. This research identified the terrestrial habitat variability of the Kemp's ridley and quantified the range of geomorphic characteristics of nesting beaches. Initial results indicate that dune width, beach width, and wind speed are significant variables in relation to nest presence, using an alpha of 0.1. Higher wind speeds and narrower beaches and foredunes favor nest presence. The average nest elevation is 1.13 m above mean sea level, which corresponds to the area directly below the potential vegetation line, and the majority of nesting occurs between the elevations of 0.68 m and 1.4 m above mean sea level. The results of this study include new information regarding Kemp's ridley beach habitat and its

  14. A multi-disciplinary approach to study coastal complex landslides: the case of Torino di Sangro (Central Italy)

    Science.gov (United States)

    Sciarra, Marco; Carabba, Luigi; Urbano, Tullio; Calista, Monia

    2016-04-01

    This work illustrates the studies carried out on a complex landslide phenomenon between the Sangro and Osento River's mouths, near Torino di Sangro village in Southern Abruzzo Region (Italy). Historical activity of this landslide is well-documented since 1916; the activation/reactivation of the movements caused several interruptions of a national railway and the damage of few houses. The Torino di Sangro case study can be regarded as representative of many large landslides distributed along the central Adriatic coast (e.g., Ancona, Ortona, Vasto and Petacciato Landslides) that affect densely populated urban areas with a large amount of man-made infrastructure. The main controlling factors of these large and deep-seated landslides are still debated. From the geological and geomorphological viewpoint, the central Adriatic coast is characterized by a low-relief landscape (mesa) carved on clay-sandstone-conglomerate bedrock belonging to the Upper Pliocene - Lower Pleistocene marine deposits and locally to the Middle Pleistocene marine to continental transitional deposits. This high coast is widely affected by slope instability (rock falls, rotational, complex and shallow landslides) on both active and inactive sea cliffs, the first being mainly affected by wave-cut erosion and the latter influenced by heavy rainfall and changes of pore pressure. The main landslide has the typical characteristics of a deep-seated gravitation deformation. The landslide study was based on a multidisciplinary approach including: 1) definition and GIS mapping of geology and geomorphology factors (slope, aspect, topographic curvature, bedrock lithology, near-surface deposits, deposit thickness and land use), by means of DTM processing, multi-temporal analysis, and large-scale geomorphological field survey; 2) monitoring system in the landslide; 3) application of empiric models for the analysis of unstable sandstone-conglomerate escarpments; 4) slope stability analysis performed using a

  15. Mapping geomorphology, groundwater bodies and springs in Simadal, Norway.

    Science.gov (United States)

    Austbø, I. L.; Øvrevik Skoglund, R.; Soldal, O. L.

    2015-12-01

    Simadal in Hardanger (Norway) is a narrow valley, famous for the waterfalls Rembedalsfossen and Skjykjedalsfossen which are regulated by Sima hydropower plant. Since the basin has been regulated between 1973-1979 the catchment area was reduced from 146km² to 35 km². There are currently plans for further expansion by also incorporating Skykjedalsvatnet, the last major remaining lake in the basin of Simaelva. In Simadal there are known to be large amounts of ground water, a greater understanding of how the groundwater interacts the river water is desirable in terms of water flow, residence time and water chemistry. Throughout the autumn of 2013 and winter of 2014 loggers were placed at various measuring points to log temperature and water levels. This included six loggers that measure temperature and pressure, as well as three loggers that measure only temperature. The goal with these loggers was to locate springs and monitor water level changes over a one-year period. In order to further investigate the water quality of the different measurement points, monthly water samples as well as pH-, and conductivity measurements were conducted. The water samples were analyzed for major ions as well as metal ions. The latter was based on earlier reported high copper levels. Flow measurements have been made in the upper and lower parts of Simadal during dry periods. The work has also included the accomplishment of Quaternary mapping; analysis of aerial photography; and using GPR. Our main concern has been to map the water resources in Simadal by registering groundwater and springs in sediments and rock faces. Furthermore, it has been desirable to draw lines to a larger regional knowledge based water management. It seems to be important to maintain a certain minimum of water of good quality, both for the ecology of the river in general, but perhaps especially considering the sustainable sea trout populations found in Simaelva today. Previous chemical, hydrogeological and fish

  16. River nomads

    DEFF Research Database (Denmark)

    2016-01-01

    sail on the Niger River between Nigeria and Mali. Crossing villages, borders and cultures, they stop only to rest by setting up camp on riverbanks or host villages. In River Nomads, we join the nomadic Kebbawa fishermen on one of their yearly crossing, experiencing their relatively adventurous...

  17. River Piracy

    Indian Academy of Sciences (India)

    There was this highly venerated river Saraswati flowing through. Haryana, Marwar and Bahawalpur in Uttarapath and emptying itself in the Gulf ofKachchh, which has been described in glowing terms by the Rigveda. "Breaking through the mountain barrier", this "swift-flowing tempestuous river surpasses in majesty and.

  18. Geomorphology of plutonium in the Northern Rio Grande

    Energy Technology Data Exchange (ETDEWEB)

    Graf, W.L. [Arizona Univ., Tempe, AZ (United States). Dept., of Geography

    1993-03-01

    Nearly all of the plutonium in the natural environment of the Northern Rio Grande is associated with soils and sediment, and river processes account for most of the mobility of these materials. A composite regional budget for plutonium based on multi-decadal averages for sediment and plutonium movement shows that 90 percent of the plutonium moving into the system is from atmospheric fallout. The remaining 10 percent is from releases at Los Alamos. Annual variation in plutonium flux and storage exceeds 100 percent. The contribution to the plutonium budget from Los Alamos is associated with relatively coarse sediment which often behaves as bedload in the Rio Grande. Infusion of these materials into the main stream were largest in 1951, 1952, 1957, and 1968. Because of the schedule of delivery of plutonium to Los Alamos for experimentation and weapons manufacturing, the latter two years are probably the most important. Although the Los Alamos contribution to the entire plutonium budget was relatively small, in these four critical years it constituted 71--86 percent of the plutonium in bedload immediately downstream from Otowi.

  19. Geomorphology of plutonium in the Northern Rio Grande

    International Nuclear Information System (INIS)

    Graf, W.L.

    1993-03-01

    Nearly all of the plutonium in the natural environment of the Northern Rio Grande is associated with soils and sediment, and river processes account for most of the mobility of these materials. A composite regional budget for plutonium based on multi-decadal averages for sediment and plutonium movement shows that 90 percent of the plutonium moving into the system is from atmospheric fallout. The remaining 10 percent is from releases at Los Alamos. Annual variation in plutonium flux and storage exceeds 100 percent. The contribution to the plutonium budget from Los Alamos is associated with relatively coarse sediment which often behaves as bedload in the Rio Grande. Infusion of these materials into the main stream were largest in 1951, 1952, 1957, and 1968. Because of the schedule of delivery of plutonium to Los Alamos for experimentation and weapons manufacturing, the latter two years are probably the most important. Although the Los Alamos contribution to the entire plutonium budget was relatively small, in these four critical years it constituted 71--86 percent of the plutonium in bedload immediately downstream from Otowi

  20. 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 independent GPR and geomorphologic data collected across the recent and sub-recent beach ridge deposits. The data analyses include coastal topography, internal dips of beach ridge layers, and sea-level measurements. A clear change in characteristic layer dip is observed between beach face and upper shoreface...

  1. Geomorphological response of a landscape to long-term tectonic and glacial processes: the upper Rhône basin, Central Swiss Alps

    Science.gov (United States)

    Stutenbecker, Laura; Schlunegger, Fritz

    2015-04-01

    The Rhône River in the Central Swiss Alps drains a 5380 km2 large basin that shows a high spatial variability of bedrock lithology, exhumation rate, glacial conditioning and climate. All of these factors were recently discussed to control erosion rates in orogenic settings in general, and particularly in the Alps (e.g. Wittmann et al. 2007, Vernon et al. 2008, Norton et al. 2010a). Thanks to various and densely distributed data, the upper Rhône basin located between the Aar massif and Lake Geneva is a suitable natural laboratory to analyze the landscape's geomorphological state and controlling factors at a basin-scale. In this study, we extract geomorphological parameters along the channels of ca. 50 tributary basins of various sizes that contribute to the sediment budget of the Rhône River either through sediment supply by torrents or debris flows. Their catchments are located in either granitic basement rocks (External Massifs), oceanic meta-sedimentary and ophiolitic rocks (Penninic nappes) or fine-grained continental-margin sediments (Helvetic nappes). The analysis of longitudinal river profiles from DEMs and slope/area relationships show that all tributary rivers within the Rhône basin are in topographic transient state that is expressed by mainly convex or concave-convex channel shapes with several knickpoints of either tectonic-lithological or glacial origin. Furthermore, the frequency distribution of elevations (hypsometry) along the river channel allows identifying glacially inherited morphologies and the recent erosional front. The combination of those different geomorphological data yields to a categorization of the tributary rivers into three endmember groups: (1) streams with highly convex profiles, testifying to a strong glacial inheritance, (2) concave-convex channels with several knickzones and inherited morphologies of past glaciations, (3) predominantly concave, relatively steep rivers with minor knickpoints and inner gorges. Assuming that

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

    Directory of Open Access Journals (Sweden)

    A. Bayat

    2017-01-01

    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

  3. Quantifying River Channel Stability at the Basin Scale

    Directory of Open Access Journals (Sweden)

    Philip J. Soar

    2017-02-01

    Full Text Available This paper examines the feasibility of a basin‐scale scheme for characterising and quantifying river reaches in terms of their geomorphological stability status and potential for morphological adjustment based on auditing stream energy. A River Energy Audit Scheme (REAS is explored, which involves integrating stream power with flow duration to investigate the downstream distribution of Annual Geomorphic Energy (AGE. This measure represents the average annual energy available with which to perform geomorphological work in reshaping the channel boundary. Changes in AGE between successive reaches might indicate whether adjustments are likely to be led by erosion or deposition at the channel perimeter. A case study of the River Kent in Cumbria, UK, demonstrates that basin‐wide application is achievable without excessive field work and data processing. However, in addressing the basin scale, the research found that this is inevitably at the cost of a number of assumptions and limitations, which are discussed herein. Technological advances in remotely sensed data capture, developments in image processing and emerging GIS tools provide the near‐term prospect of fully quantifying river channel stability at the basin scale, although as yet not fully realized. Potential applications of this type of approach include system‐wide assessment of river channel stability and sensitivity to land‐use or climate change, and informing strategic planning for river channel and flood risk management.

  4. GIS-based hazard and risk maps of the Douro river basin (north-eastern Portugal

    Directory of Open Access Journals (Sweden)

    José Gomes Santos

    2015-02-01

    Full Text Available The Douro river basin, in north-eastern Portugal, is a very complex region in terms of its geomorphological structure and morphodynamics. More specifically, the region – the Port Wine-growing region, a UNESCO heritage site – is a landslide-prone area resulting from several factors intrinsic to the bedrock and its detritic cover, combined with factors capable of triggering slope instability mechanisms, such as intense rainfall and human activities. Recently, due to intense rainfall and human activities, frequent rock and mud slides occurred, some of them catastrophic, killing people and damaging property. In the last decade (2000–2010, an accurate inventory of these catastrophic events was made, showing that these events occurred near local small towns, Peso da Régua (2001, Armamar (2003 and Carrazeda de Ansiães (2007. In this paper, we present a case study using field data and Geographic Information Systems (GIS tools to evaluate landslide hazard and risk assessment following multicriteria evaluation techniques.

  5. River habitat assessment for ecological restoration of Wei River Basin, China.

    Science.gov (United States)

    Yang, Tao; Wang, Shuo; Li, Xiaoping; Wu, Ting; Li, Li; Chen, Jia

    2018-04-11

    As an important composition component of river ecosystems, river habitats must undergo quality assessment to potentially provide scientific basis for river ecological restoration. Substrate composition, habitat complexity, bank erosion degree, river meandering degree, human activity intensity, vegetation buffer width, water quality, and water condition were determined as indicators for river habitat assessment. The comprehensive habitat quality index (CHQI) was established for the Wei River Basin. In addition, the indicator values were determined on the basis of a field investigation at 12 national hydrological stations distributed across the Wei, Jing, and Beiluo Rivers. The analytic hierarchy process was used to determine the indicator weights and thus distinguish the relative importance of the assessment indicator system. Results indicated that the average CHQIs for the Wei, Jing, and Beiluo Rivers were 0.417, 0.508, and 0.304, respectively. The river habitat quality for the three rivers was well. As for the whole river basin, the river habitat quality for 25% of the cross section was very well, the other 25% was well, and the 50% remaining was in critical state. The river habitat quality of the Jing River was better than that of the Wei and Beiluo Rivers.

  6. Geomorphological and sedimentary processes of the glacially influenced northwestern Iberian continental margin and abyssal plains

    Science.gov (United States)

    Llave, Estefanía; Jané, Gloria; Maestro, Adolfo; López-Martínez, Jerónimo; Hernández-Molina, F. Javier; Mink, Sandra

    2018-07-01

    The offshore region of northwestern Iberia offers an opportunity to study the impacts of along-slope processes on the morphology of a glacially influenced continental margin, which has traditionally been conceptually characterised by predominant down-slope sedimentary processes. High-resolution multibeam bathymetry, acoustic backscatter and ultrahigh-resolution seismic reflection profile data are integrated and analysed to describe the present-day and recent geomorphological features and to interpret their associated sedimentary processes. Seventeen large-scale seafloor morphologies and sixteen individual echo types, interpreted as structural features (escarpments, marginal platforms and related fluid escape structures) and depositional and erosional bedforms developed either by the influence of bottom currents (moats, abraded surfaces, sediment waves, contourite drifts and ridges) or by gravitational features (gullies, canyons, slides, channel-levee complexes and submarine fans), are identified for the first time in the study area (spanning 90,000 km2 and water depths of 300 m to 5 km). Different types of slope failures and turbidity currents are mainly observed on the upper and lower slopes and along submarine canyons and deep-sea channels. The middle slope morphologies are mostly determined by the actions of bottom currents (North Atlantic Central Water, Mediterranean Outflow Water, Labrador Sea Water and North Atlantic Deep Water), which thereby define the margin morphologies and favour the reworking and deposition of sediments. The abyssal plains (Biscay and Iberian) are characterised by pelagic deposits and channel-lobe systems (the Cantabrian and Charcot), although several contourite features are also observed at the foot of the slope due to the influence of the deepest water masses (i.e., the North Atlantic Deep Water and Lower Deep Water). This work shows that the study area is the result of Mesozoic to present-day tectonics (e.g. the marginal platforms

  7. Radiocarbon dating of floodplain and young terraces alluvial sediments of Latvia rivers

    International Nuclear Information System (INIS)

    Eberhards, G.; Saltupe, B.

    2000-01-01

    This paper include new information about alluvial sediments structure and radiocarbon data of some Latvia free-meandering rivers (Gauja, Ogre, Liela and Maza Jugla, Daugava) floodplains and first terraces. In this present study we examined Gauja river floodplains in the different geomorphological and geological areas. Radiocarbon dating add the fact that the high level floodplain (4-5 m) formation and sediment accumulation take place 3000-5000 years before present (BP) middle level floodplains formed 1500-2100 years BP. Investigations show that one river terraces and floodplains with same relative height have a several absolute age. The rivers crossed same hypsometrical regions (highlands, lowlands) downstream in lowlands alluvial terraces performed as floodplains or from from floodplains to terraces with same height. On the highest, middle and in the lower parts of the rivers with free - meandering channel to - day the dynamic balance of the channel processes exits 4000-5000 years. (author)

  8. Long-term hydrodynamic response induced by past climatic and geo-morphologic forcing: The case of the Paris basin, France

    International Nuclear Information System (INIS)

    Jost, A.; Violette, S.; Goncalves, J.; Ledoux, E.; Guyomard, Y.; Guillocheau, F.; Kageyama, M.; Ramstein, G.; Suc, J.P.

    2007-01-01

    In the framework of safe underground storage of radioactive waste in low-permeability layers, it is essential to evaluate the mobility of deep groundwaters over timescales of several million years. On these timescales, the environmental evolution of a repository should depend upon a range of natural processes that are primarily driven by climate and geo-morphologic variations. In this paper, the response of the Paris basin groundwater system to variations in its hydrodynamic boundary conditions induced by past climate and geodynamic changes over the last five million years is investigated. A three-dimensional transient modelling of the Paris basin aquifer/aquitard system was developed using the code NEWSAM (Ecole des Mines de Paris, ENSMP). The geometry and hydrodynamic parameters of the model originate from a basin model, NEWBAS (ENSMP), built to simulate the geological history of the basin. Geo-morphologic evolution is deduced from digital elevation model analysis, which allows to estimate river-valley incision and alpine uplift. Climate forcing results from paleo-climate modelling experiments using the LMDz atmospheric general circulation model (Institut Pierre Simon Laplace) with a refined spatial resolution, for the present, the Last Glacial Maximum (21 ka) and the Middle Pliocene Warmth (similar to 3 Ma). The water balance is computed by the distributed hydrological model MODSUR (ENSMP). Results about the simulated evolution of piezometric heads in the system in response to the altered boundary conditions are presented, in particular in the vicinity of ANDRA's Bure potential repository site within the Callovo-Oxfordian argillaceous layer. For the present, the comparison of head patterns between steady state and time dependent simulation shows little differences for aquifer layers close to the surface but suggests a transient state of the current system in the main aquitards of the basin and in the deep aquifers, characterized by abnormally low fluid

  9. Vegetation Response and Landscape Dynamics of Indian Summer Monsoon Variations during Holocene: An Eco-Geomorphological Appraisal of Tropical Evergreen Forest Subfossil Logs

    Science.gov (United States)

    Kumaran, Navnith K. P.; Padmalal, Damodaran; Nair, Madhavan K.; Limaye, Ruta B.; Guleria, Jaswant S.; Srivastava, Rashmi; Shukla, Anumeha

    2014-01-01

    The high rainfall and low sea level during Early Holocene had a significant impact on the development and sustenance of dense forest and swamp-marsh cover along the southwest coast of India. This heavy rainfall flooded the coastal plains, forest flourishing in the abandoned river channels and other low-lying areas in midland.The coastline and other areas in lowland of southwestern India supply sufficient evidence of tree trunks of wet evergreen forests getting buried during the Holocene period under varying thickness of clay, silty-clay and even in sand sequences. This preserved subfossil log assemblage forms an excellent proxy for eco-geomorphological and palaeoclimate appraisal reported hitherto from Indian subcontinent, and complements the available palynological data. The bulk of the subfossil logs and partially carbonized wood remains have yielded age prior to the Holocene transgression of 6.5 k yrs BP, suggesting therein that flooding due to heavy rainfall drowned the forest cover, even extending to parts of the present shelf. These preserved logs represent a unique palaeoenvironmental database as they contain observable cellular structure. Some of them can even be compared to modern analogues. As these woods belong to the Late Pleistocene and Holocene, they form a valuable source of climate data that alleviates the lack of contemporaneous meteorological records. These palaeoforests along with pollen proxies depict the warmer environment in this region, which is consistent with a Mid Holocene Thermal Maximum often referred to as Holocene Climate Optimum. Thus, the subfossil logs of tropical evergreen forests constitute new indices of Asian palaeomonsoon, while their occurrence and preservation are attributed to eco-geomorphology and hydrological regimes associated with the intensified Asian Summer Monsoon, as recorded elsewhere. PMID:24727672

  10. Benchmarking wide swath altimetry-based river discharge estimation algorithms for the Ganges river system

    Science.gov (United States)

    Bonnema, Matthew G.; Sikder, Safat; Hossain, Faisal; Durand, Michael; Gleason, Colin J.; Bjerklie, David M.

    2016-04-01

    The objective of this study is to compare the effectiveness of three algorithms that estimate discharge from remotely sensed observables (river width, water surface height, and water surface slope) in anticipation of the forthcoming NASA/CNES Surface Water and Ocean Topography (SWOT) mission. SWOT promises to provide these measurements simultaneously, and the river discharge algorithms included here are designed to work with these data. Two algorithms were built around Manning's equation, the Metropolis Manning (MetroMan) method, and the Mean Flow and Geomorphology (MFG) method, and one approach uses hydraulic geometry to estimate discharge, the at-many-stations hydraulic geometry (AMHG) method. A well-calibrated and ground-truthed hydrodynamic model of the Ganges river system (HEC-RAS) was used as reference for three rivers from the Ganges River Delta: the main stem of Ganges, the Arial-Khan, and the Mohananda Rivers. The high seasonal variability of these rivers due to the Monsoon presented a unique opportunity to thoroughly assess the discharge algorithms in light of typical monsoon regime rivers. It was found that the MFG method provides the most accurate discharge estimations in most cases, with an average relative root-mean-squared error (RRMSE) across all three reaches of 35.5%. It is followed closely by the Metropolis Manning algorithm, with an average RRMSE of 51.5%. However, the MFG method's reliance on knowledge of prior river discharge limits its application on ungauged rivers. In terms of input data requirement at ungauged regions with no prior records, the Metropolis Manning algorithm provides a more practical alternative over a region that is lacking in historical observations as the algorithm requires less ancillary data. The AMHG algorithm, while requiring the least prior river data, provided the least accurate discharge measurements with an average wet and dry season RRMSE of 79.8% and 119.1%, respectively, across all rivers studied. This poor

  11. Physical heterogeneity and aquatic community function in river networks: A case study from the Kanawha River Basin, USA

    Science.gov (United States)

    Thoms, M. C.; Delong, M. D.; Flotemersch, J. E.; Collins, S. E.

    2017-08-01

    The geomorphological character of a river network provides the template upon which evolution acts to create unique biological communities. Deciphering commonly observed patterns and processes within riverine landscapes resulting from the interplay between physical and biological components is a central tenet for the interdisciplinary field of river science. Relationships between the physical heterogeneity and food web character of functional process zones (FPZs) - large tracts of river with a similar geomorphic character -in the Kanawha River (West Virginia, USA) are examined in this study. Food web character was measured as food chain length (FCL), which reflects ecological community structure and ecosystem function. Our results show that the same basal resources were present throughout the Kanawha River but that their assimilation into the aquatic food web by primary consumers differed between FPZs. Differences in the trophic position of higher consumers (fish) were also recorded between FPZs. Overall, the morphological heterogeneity and heterogeneity of the river bed sediment of FPZs were significantly correlated with FCL. Specifically, FCL increases with greater FPZ physical heterogeneity. The result of this study does not support the current paradigm that ecosystem size is the primary determinant of food web character in river ecosystems.

  12. Mega-geomorphology: Mars vis a vis Earth

    Science.gov (United States)

    Sharp, R. P.

    1985-01-01

    The areas of chaotic terrain, the giant chasma of the Valles Marineris region, the complex linear and circular depressions of Labyrinthus Noctis on Mars all suggest the possibility of large scale collapse of parts of the martian crust within equatorial and sub equatorial latitudes. It seems generally accepted that the above features are fossil, being perhaps, more than a billion years old. It is possible that parts of Earth's crust experienced similar episodes of large scale collapse sometime early in the evolution of the planet.

  13. Methods and tools to simulate the effect of economic instruments in complex water resources systems. Application to the Jucar river basin.

    Science.gov (United States)

    Lopez-Nicolas, Antonio; Pulido-Velazquez, Manuel

    2014-05-01

    The main challenge of the BLUEPRINT to safeguard Europe's water resources (EC, 2012) is to guarantee that enough good quality water is available for people's needs, the economy and the environment. In this sense, economic policy instruments such as water pricing policies and water markets can be applied to enhance efficient use of water. This paper presents a method based on hydro-economic tools to assess the effect of economic instruments on water resource systems. Hydro-economic models allow integrated analysis of water supply, demand and infrastructure operation at the river basin scale, by simultaneously combining engineering, hydrologic and economic aspects of water resources management. The method made use of the simulation and optimization hydroeconomic tools SIMGAMS and OPTIGAMS. The simulation tool SIMGAMS allocates water resources among the users according to priorities and operating rules, and evaluate economic scarcity costs of the system by using economic demand functions. The model's objective function is designed so that the system aims to meet the operational targets (ranked according to priorities) at each month while following the system operating rules. The optimization tool OPTIGAMS allocates water resources based on an economic efficiency criterion: maximize net benefits, or alternatively, minimizing the total water scarcity and operating cost of water use. SIMGAS allows to simulate incentive water pricing policies based on marginal resource opportunity costs (MROC; Pulido-Velazquez et al., 2013). Storage-dependent step pricing functions are derived from the time series of MROC values at a certain reservoir in the system. These water pricing policies are defined based on water availability in the system (scarcity pricing), so that when water storage is high, the MROC is low, while low storage (drought periods) will be associated to high MROC and therefore, high prices. We also illustrate the use of OPTIGAMS to simulate the effect of ideal water

  14. Geomorphological evolution of a newly restored upland temporary stream

    Science.gov (United States)

    Marteau, Baptiste; Batalla, Ramon J.; Gibbins, Chris N.; Green, David R.; Vericat, Damià

    2015-04-01

    The river Ehen, NW England, has been designated as a Special Area of Conservation (SAC) as it hosts England's largest population of freshwater pearl mussels (M. margaritifera). One of the Ehen's main headwater tributary, Ben Gill, was diverted to Ennerdale Lake in the 1970s to help increase the volume of water available for abstraction. Concerns over this diversion on the hydrology and sediment dynamics of the Ehen has led to the reconnection of this temporary stream as part of a project designed to improve habitat conditions for mussels in the Ehen. The reconnection has involved the construction of a new section of channel, following the natural (pre-diversion) course of Ben Gill. This paper presents findings of research designed to track the morphological evolution of the newly created Ben Gill channel. The work follows a previous research in which fluvial dynamics in the Ehen were studied before the reconnection of Ben Gill. Morpho-sedimentary dynamics are analysed at multiple scales: from the movement of individual particles, to changes on channel morphology following competent flow events. Changes in the channel's grain size distributions have been investigated in different sections, while bed mobility has been assessed using a combination of radio frequency identification (RFID) tags inserted into representative particles and painted bed patches. Additionally, digital elevation models (DEMs) of the entire new channel have been constructed by means of automatic digital photogrammetry using high resolution aerial photography taken by an unmanned aerial vehicle (UAV). DEMs of difference (DoD) between major flow events have been used to track lateral and longitudinal changes in the channel at a spatial resolution of less than 5cm. Finally, in order to link sedimentological changes in the new channel to its impact on the main stem Ehen, morpho-sedimentary changes of a gravel bar at the confluence have been monitored combining tracers (i.e. RFID) and repeated

  15. Development of a channel classification to evaluate potential for cottonwood restoration, lower segments of the Middle Missouri River, South Dakota and Nebraska

    Science.gov (United States)

    Jacobson, Robert B.; Elliott, Caroline M.; Huhmann, Brittany L.

    2010-01-01

    This report documents development of a spatially explicit river and flood-plain classification to evaluate potential for cottonwood restoration along the Sharpe and Fort Randall segments of the Middle Missouri River. This project involved evaluating existing topographic, water-surface elevation, and soils data to determine if they were sufficient to create a classification similar to the Land Capability Potential Index (LCPI) developed by Jacobson and others (U.S. Geological Survey Scientific Investigations Report 2007–5256) and developing a geomorphically based classification to apply to evaluating restoration potential.Existing topographic, water-surface elevation, and soils data for the Middle Missouri River were not sufficient to replicate the LCPI. The 1/3-arc-second National Elevation Dataset delineated most of the topographic complexity and produced cumulative frequency distributions similar to a high-resolution 5-meter topographic dataset developed for the Lower Missouri River. However, lack of bathymetry in the National Elevation Dataset produces a potentially critical bias in evaluation of frequently flooded surfaces close to the river. High-resolution soils data alone were insufficient to replace the information content of the LCPI. In test reaches in the Lower Missouri River, soil drainage classes from the Soil Survey Geographic Database database correctly classified 0.8–98.9 percent of the flood-plain area at or below the 5-year return interval flood stage depending on state of channel incision; on average for river miles 423–811, soil drainage class correctly classified only 30.2 percent of the flood-plain area at or below the 5-year return interval flood stage. Lack of congruence between soil characteristics and present-day hydrology results from relatively rapid incision and aggradation of segments of the Missouri River resulting from impoundments and engineering. The most sparsely available data in the Middle Missouri River were water

  16. Using a Bayesian network to predict barrier island geomorphologic characteristics

    Science.gov (United States)

    Gutierrez, Ben; Plant, Nathaniel G.; Thieler, E. Robert; Turecek, Aaron

    2015-01-01

    Quantifying geomorphic variability of coastal environments is important for understanding and describing the vulnerability of coastal topography, infrastructure, and ecosystems to future storms and sea level rise. Here we use a Bayesian network (BN) to test the importance of multiple interactions between barrier island geomorphic variables. This approach models complex interactions and handles uncertainty, which is intrinsic to future sea level rise, storminess, or anthropogenic processes (e.g., beach nourishment and other forms of coastal management). The BN was developed and tested at Assateague Island, Maryland/Virginia, USA, a barrier island with sufficient geomorphic and temporal variability to evaluate our approach. We tested the ability to predict dune height, beach width, and beach height variables using inputs that included longer-term, larger-scale, or external variables (historical shoreline change rates, distances to inlets, barrier width, mean barrier elevation, and anthropogenic modification). Data sets from three different years spanning nearly a decade sampled substantial temporal variability and serve as a proxy for analysis of future conditions. We show that distinct geomorphic conditions are associated with different long-term shoreline change rates and that the most skillful predictions of dune height, beach width, and beach height depend on including multiple input variables simultaneously. The predictive relationships are robust to variations in the amount of input data and to variations in model complexity. The resulting model can be used to evaluate scenarios related to coastal management plans and/or future scenarios where shoreline change rates may differ from those observed historically.

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

    Science.gov (United States)

    Mosaad, Sayed

    2017-10-01

    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. MÉTODOS DE SENSORIAMENTO REMOTO APLICADOS À GEOMORFOLOGIA - METHODS IN REMOTESENSING APPLY IN GEOMORPHOLOGY

    Directory of Open Access Journals (Sweden)

    Thiago Morato de Carvalho

    2007-12-01

    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.

  19. Coastal coho salmon research in the West Fork Smith River: Patterns of coho salmon size and survival within a complex watershed

    Science.gov (United States)

    Effective habitat restoration planning requires the ability to anticipate fish population responses to altered habitats. The EPA has conducted network-scale research to document habitat-specific growth and survival of juvenile salmonids in a complex watershed. These findings ha...

  20. Influence of Geomorphology on the Physiognomy of Colophospermum mopane and its Effect on Browsing in Central Namibia

    OpenAIRE

    TESHIROGI, Koki

    2010-01-01

    Colophospermum mopane is a characteristic tree species indigenous to Southern Africa, where it forms 'mopane vegetation.' Mopane plays an important role in livestock farming, and the physiognomy of mopane influences the availability of feed. This study clarified the relationship between the difference in mopane physiognomy and the browsing activity of goats with reference to geomorphology. The physiognomy of mopane corresponded to geomorphological characteristics of surface structures and soi...

  1. GEOMORPHOLOGY OF JOÃO PESSOA MUNICIPALITY AND ITS ANTHROPOGENIC AND ENVIRONMENTAL ASPECTS

    OpenAIRE

    Max Furrier; Tamires Silva Barbosa

    2016-01-01

    The objective of this paper is to study the geomorphology of the municipality of João Pessoa, Paraíba State, Brazil, analyzing the outlines of the current natural landforms as well as technogenic relief. From this analysis, morphostructural and morphosculptural units, patterns and landforms, shape types and current morphogenetic processes were identified and quantified in the municipality along with landforms produced exclusively by human processes. The current forms and technogenic relief ob...

  2. Geomorphologically effective floods from moraine-dammed lakes in the Cordillera Blanca, Peru

    Czech Academy of Sciences Publication Activity Database

    Emmer, Adam

    2017-01-01

    Roč. 177, DEC (2017), s. 220-234 ISSN 0277-3791 R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:86652079 Keywords : Andes * Documentary data * Geomorphology * glof * Lichenometry * Little Ice Age * Moraine-dammed lake * Outburst flood * South America Subject RIV: EH - Ecology, Behaviour OBOR OECD: Environmental sciences (social aspects to be 5.7) Impact factor: 4.797, year: 2016

  3. Geomorphology Drives Amphibian Beta Diversity in Atlantic Forest Lowlands of Southeastern Brazil

    OpenAIRE

    Luiz, Amom Mendes; Le?o-Pires, Thiago Augusto; Sawaya, Ricardo J.

    2016-01-01

    Beta diversity patterns are the outcome of multiple processes operating at different scales. Amphibian assemblages seem to be affected by contemporary climate and dispersal-based processes. However, historical processes involved in present patterns of beta diversity remain poorly understood. We assess and disentangle geomorphological, climatic and spatial drivers of amphibian beta diversity in coastal lowlands of the Atlantic Forest, southeastern Brazil. We tested the hypothesis that geomorph...

  4. Geomorphology and natural hazards of the selected glacial valleys, Cordillera Blanca, Peru

    Czech Academy of Sciences Publication Activity Database

    Klimeš, Jan

    2012-01-01

    Roč. 47, č. 2 (2012), s. 25-31 ISSN 0300-5402 R&D Projects: GA ČR(CZ) GAP209/11/1000 Institutional research plan: CEZ:AV0Z30460519 Keywords : geomorphologic map * natural hazards * glacial lakes Subject RIV: DE - Earth Magnetism, Geodesy, Geography http://web.natur.cuni.cz/ksgrrsek/acta/2012/Geographica_2_2012_Klimes.pdf

  5. GEOMORPHOLOGY AND SEDIMENTOLOGY OF UNION GLACIER AREA, ELLSWORTH MOUNTAINS, OCCIDENTAL ANTARCTICA

    Directory of Open Access Journals (Sweden)

    Vanessa do Couto Silva Costa

    2017-08-01

    Full Text Available The work aims to investigate the geomorphological and sedimentological aspects of Union Glacier area (79°45’00’’S; 82°30’00’’W, southern sector of Ellsworth Mountains. Geomorphological cartography based on 15 m ASTER (2010 satellite imagery and field works were carried out during the Brazilian expedition (2011/2012 enabled the identification of morainic formations: ice-cored hummock moraines, supraglacial moraines, and recession moraines in the interior of the valleys. With the exception of the latter one, all types of moraines have been developed on the blue-ice areas. The evidence for paleo wet-based glacial conditions is reconstructed from a range of geomorphological record, including exposed abrasion marks, striations and glaciotectonic deformation. This type of deformation is represented by lee sides of oversteepening bedrock promontories which follow the tributaries of glaciers ice flow. Glacial sediments were collected from the moraines for granulometric and morphometric analyses. They show the prevalence of sandy gravel and sand texture, low quantity of fine fractions, and absence of attributes such as striated and faceted clasts, which indicate, on the other side, low-sediment transport capacity from the ice sheet bottom. It is inferred that the moraine debris are originated from local sources. Weathering action and constant katabatic winds are possibly the major agents of transport and alteration of the exposed sediments. The geomorphological features reveal an ancient thicker ice sheet, and sedimentary characteristics of the morainic formations reveal a latter thinner ice sheet in this sector of Ellsworth Mountains.

  6. Long term effects on potential repository sites: climatic and geomorphological changes

    International Nuclear Information System (INIS)

    Seddon, M.B.; Worsley, P.

    1985-05-01

    A study of the effects of climatic variability on the geomorphological processes operating on the landscape are important in the study of radioactive waste repository sites. The effects of glacial erosion and deposition are fundamental to an examination of repository safety, particularly in North Britain. Rates of climatic shift need to be examined. Predictive simulation models, based on a knowledge of past climatic events, for future global climates are proposed. (UK)

  7. CHANGING FLOOD FREQUENCY IN SCOTLAND: IMPLICATIONS FOR CHANNEL GEOMORPHOLOGY, ECOLOGY AND MANAGEMENT

    OpenAIRE

    Thompson, Fiona Hilary

    2017-01-01

    The effect of climate on the fluvial system has long been investigated due the significant impact it can have on a river’s hydrological regime and fluvial processes. In recent years this interest has increased as global changes in climate are expected to bring more frequent high magnitude flood events globally and to North West Europe in particular. Despite the knowledge that the frequency and magnitude of floods is to increase, less is known about the geomorphological implicat...

  8. Hierarchically nested river landform sequences

    Science.gov (United States)

    Pasternack, G. B.; Weber, M. D.; Brown, R. A.; Baig, D.

    2017-12-01

    River corridors exhibit landforms nested within landforms repeatedly down spatial scales. In this study we developed, tested, and implemented a new way to create river classifications by mapping domains of fluvial processes with respect to the hierarchical organization of topographic complexity that drives fluvial dynamism. We tested this approach on flow convergence routing, a morphodynamic mechanism with different states depending on the structure of nondimensional topographic variability. Five nondimensional landform types with unique functionality (nozzle, wide bar, normal channel, constricted pool, and oversized) represent this process at any flow. When this typology is nested at base flow, bankfull, and floodprone scales it creates a system with up to 125 functional types. This shows how a single mechanism produces complex dynamism via nesting. Given the classification, we answered nine specific scientific questions to investigate the abundance, sequencing, and hierarchical nesting of these new landform types using a 35-km gravel/cobble river segment of the Yuba River in California. The nested structure of flow convergence routing landforms found in this study revealed that bankfull landforms are nested within specific floodprone valley landform types, and these types control bankfull morphodynamics during moderate to large floods. As a result, this study calls into question the prevailing theory that the bankfull channel of a gravel/cobble river is controlled by in-channel, bankfull, and/or small flood flows. Such flows are too small to initiate widespread sediment transport in a gravel/cobble river with topographic complexity.

  9. Linking hydrology, morphodynamics and ecology to assess the restoration potential of the heavily regulated Sarca River, NE Italy

    Science.gov (United States)

    Carolli, Mauro; Zolezzi, Guido; Pellegrini, Stefano; Gelmini, Francesca; Deriu, Micaela

    2017-04-01

    We develop an integrated eco-hydro-morphological quantitative investigation of the upper course of the Alpine Sarca River (NE Italy), for the purpose of assessing its potential in terms of environmental restoration. The Sarca River has been subject to heavy exploitation for hydropower production since the 1950s through a complex infrastructural system. As for many regulated Alpine rivers, increasing local interest has recently been developing to design and implement river restoration measures to improve the environmental conditions and ecosystem services that the river can provide. The aim of the work is to develop and apply a quantitative approach for a preliminary assessment of the successful potential of different river restoration options in the light of the recent eco-hydro-morphological dynamics of the Sarca river system at the catchment scale. The proposed analysis consists of three main steps: (1) detection of the main drivers of flow and sediment supply regimes alteration and characterization of such alteration; (2) a quantification of the effects of those alterations on geomorphic processes and fish habitat conditions; (3) the analysis of the restoration potential in the light of the results of the previous assessment. The analysis is tailored to the existing data availability, which is relatively high as for most river systems of comparable size in Europe, but not as much as in the case of a targeted research project, thus providing a representative case for many other regulated river catchments. Hydrological alteration is quantified by comparing recent (20 years) streamflow time series with a reconstructed series of analogous length, using a hydrological model that has been run excluding any man-made water abstraction, release and artificial reservoirs. upstream and downstream a large dam in the middle course of the river. By choosing the adult marble trout as target (endemic) fish species, effects of the alterations on the temporal and spatial habitat

  10. A Transient Landscape: Geospatial Analysis and Numerical Modeling of Coastal Geomorphology in the Outer Banks, North Carolina

    Science.gov (United States)

    Hardin, Eric Jon

    manual digitization lack. Furthermore, the approach can be fully implemented with standard Geographic Information System (GIS) functionality, resulting in efficiency and ease of implementation. With this approach, a raster-based implementation of the U.S. Geological Survey (USGS) storm impact scale (designed to assess storm vulnerability of barrier islands) was developed. Vulnerability of 4km of the Outer Banks to Hurricane Isabel (2003) was assessed. The demonstrated approach produced vulnerability mapping at the high resolution of the input Digital Elevation Model (DEM)---providing results at the scale needed for local management, in contrast to the USGS approach, which is designed for continental scale vulnerability assessment. However, geospatial techniques cannot fully explain the observed geomorphology. Therefore, we present the Smoothed Particle Hydrodynamics (SPH) implementation of the Sauermann model for wind-driven sand transport. The SPH implementation enables the full nonlinearity of the model to be applied to complex scenarios that are typical of coastal landscapes. Through application of the SPH model and Computational Fluid Dynamics (CFD) modeling of the windborne surface shear stress (which drives sand transport), we present the sediment flux at two study sites along the Outer Banks. Scenarios were tested that involved steady-state surface shear stress as well as scenarios with intermittent variations in the surface shear stress. Results showed that intermittency in the surface shear stress has the potential to greatly influence the resulting flux. However, the degree to which intermittency does alter the flux is highly dependent on wind characteristics and wind direction relative to the orientation of salient topographic features.

  11. Soil and geomorphological parameters to characterize natural environmental and human induced changes within the Guadarrama Range (Central Spain)

    Science.gov (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.

    2016-04-01

    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

  12. A geomorphological approach to sustainable planning and management of the coastal zone of Kuwait

    Science.gov (United States)

    Al Bakri, Dhia

    1996-10-01

    The coastal zone in Kuwait has been under a considerable pressure from conflicting land uses since the early 1960s, as well as from the destruction and oil pollution caused by the Gulf War. To avoid further damage and to protect the coastal heritage it is essential to adopt an environmentally sustainable management process. This paper shows how the study of coastal geomorphology can provide a sound basis for sustainable planning and management. Based on coastal landforms, sediments and processes, the coastline of Kuwait was divided into nine geomorphic zones. These zones were grouped into two main geomorphic provinces. The northern province is marked by extensive muddy intertidal flats and dominated by a depositional and low-energy environment. The southern geomorphic province is characterised by relatively steep beach profiles, rocky/sandy tidal flats and a moderate to high-energy environment. The study has demonstrated that pollution, benthic ecology and other environmental conditions of the coast are a function of coastline geomorphology, sedimentology and related processes. The geomorphological information was used to determine the coastal vulnerability and to assess the environmental impacts of development projects and other human activities. Several strategies were outlined to integrate the geomorphic approach into the management of the coastal resources.

  13. GEOMORPHOLOGICAL ECOGEOGRAPHICAL VARIABLES DEFINIG FEATURES OF ECOLOGICAL NICHE OF COMMON MILKWEED (ASCLEPIAS SYRIACA L.

    Directory of Open Access Journals (Sweden)

    O. M. Kunah

    2016-04-01

    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.

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

    Science.gov (United States)

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

    2017-10-01

    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. Syntectonic Mississippi River Channel Response: Integrating River Morphology and Seismic Imaging to Detect Active Faults

    Science.gov (United States)

    Magnani, M. B.

    2017-12-01

    Alluvial rivers, even great rivers such as the Mississippi, respond to hydrologic and geologic controls. Temporal variations of valley gradient can significantly alter channel morphology, as the river responds syntectonically to attain equilibrium. The river will alter its sinuosity, in an attempt to maintain a constant gradient on a surface that changes slope through time. Therefore, changes of river pattern can be the first clue that active tectonics is affecting an area of pattern change. Here I present geomorphological and seismic imaging evidence of a previously unknown fault crossing the Mississippi river south of the New Madrid seismic zone, between Caruthersville, Missouri and Osceola, Arkansas, and show that both datasets support Holocene fault movement, with the latest slip occurring in the last 200 years. High resolution marine seismic reflection data acquired along the Mississippi river imaged a NW-SE striking north-dipping fault displacing the base of the Quaternary alluvium by 15 m with reverse sense of movement. The fault consistently deforms the Tertiary, Cretaceous and Paleozoic formations. Historical river channel planforms dating back to 1765 reveal that the section of the river channel across the fault has been characterized by high sinuosity and steep projected-channel slope compared to adjacent river reaches. In particular, the reach across the fault experienced a cutoff in 1821, resulting in a temporary lowering of sinuosity followed by an increase between the survey of 1880 and 1915. Under the assumption that the change in sinuosity reflects river response to a valley slope change to maintain constant gradient, I use sinuosity through time to calculate the change in valley slope since 1880 and therefore to estimate the vertical displacement of the imaged fault in the past 200 years. Based on calculations so performed, the vertical offset of the fault is estimated to be 0.4 m, accrued since at least 1880. If the base of the river alluvium

  16. Vegetation Carbon Storage, Spatial Patterns and Response to Altitude in Lancang River Basin, Southwest China

    Directory of Open Access Journals (Sweden)

    Long Chen

    2016-01-01

    Full Text Available Vegetation plays a very important role of carbon (C sinks in the global C cycle. With its complex terrain and diverse vegetation types, the Lancang River Basin (LRB of southwest China has huge C storage capacity. Therefore, understanding the spatial variations and controlling mechanisms of vegetation C storage is important to understand the regional C cycle. In this study, data from a forest inventory and field plots were used to estimate and map vegetation C storage distribution in the LRB, to qualify the quantitative relationships between vegetation C density and altitude at sublot and township scale, and a linear model or polynomial model was used to identify the relationship between C density and altitude at two spatial scales and two statistical scales. The results showed that a total of 300.32 Tg C was stored in the LRB, an important C sink in China. The majority of C storage was contributed by forests, notably oaks. The vegetation C storage exhibited nonlinear variation with latitudinal gradients. Altitude had tremendous influences on spatial patterns of vegetation C storage of three geomorphological types in the LRB. C storage decreased with increasing altitude at both town and sublot scales in the flat river valley (FRV region and the mid-low mountains gorge (MMG region, and first increased then decreased in the alpine gorge (AG region. This revealed that, in southwest China, altitude changes the latitudinal patterns of vegetation C storage; especially in the AG area, C density in the mid-altitude (3100 m area was higher than that of adjacent areas.

  17. Advances in river ice hydrology 1999-2003

    Science.gov (United States)

    Morse, Brian; Hicks, Faye

    2005-01-01

    In the period 1999 to 2003, river ice has continued to have important socio-economic impacts in Canada and other Nordic countries. Concurrently, there have been many important advances in all areas of Canadian research into river ice engineering and hydrology. For example: (1) River ice processes were highlighted in two special journal issues (Canadian Journal of Civil Engineering in 2003 and Hydrological Processes in 2002) and at five conferences (Canadian Committee on River Ice Processes and the Environment in 1999, 2001 and 2003, and International Association of Hydraulic Research in 2000 and 2002). (2) A number of workers have clearly advanced our understanding of river ice processes by bringing together disparate information in comprehensive review articles. (3) There have been significant advances in river ice modelling. For example, both one-dimensional (e.g. RIVICE, RIVJAM, ICEJAM, HEC-RAS, etc.) and two-dimensional (2-D; www.river2d.ca) public-domain ice-jam models are now available. Work is ongoing to improve RIVER2D, and a commercial 2-D ice-process model is being developed. (4) The 1999-2003 period is notable for the number of distinctly hydrological and ecological studies. On the quantitative side, many are making efforts to determine streamflow during the winter period. On the ecological side, some new publications have addressed the link to water quality (temperature, dissolved oxygen, nutrients and pollutants), and others have dealt with sediment transport and geomorphology (particularly as it relates to break-up), stream ecology (plants, food cycle, etc.) and fish habitat.There is the growing recognition, that these types of study require collaborative efforts. In our view, the main areas requiring further work are: (1) to interface geomorphological and habitat models with quantitative river ice hydrodynamic models; (2) to develop a manager's toolbox (database management, remote sensing, forecasting, intervention methodologies, etc.) to enable

  18. The science and practice of river restoration

    Science.gov (United States)

    Wohl, Ellen; Lane, Stuart N.; Wilcox, Andrew C.

    2015-08-01

    River restoration is one of the most prominent areas of applied water-resources science. From an initial focus on enhancing fish habitat or river appearance, primarily through structural modification of channel form, restoration has expanded to incorporate a wide variety of management activities designed to enhance river process and form. Restoration is conducted on headwater streams, large lowland rivers, and entire river networks in urban, agricultural, and less intensively human-altered environments. We critically examine how contemporary practitioners approach river restoration and challenges for implementing restoration, which include clearly identified objectives, holistic understanding of rivers as ecosystems, and the role of restoration as a social process. We also examine challenges for scientific understanding in river restoration. These include: how physical complexity supports biogeochemical function, stream metabolism, and stream ecosystem productivity; characterizing response curves of different river components; understanding sediment dynamics; and increasing appreciation of the importance of incorporating climate change considerations and resiliency into restoration planning. Finally, we examine changes in river restoration within the past decade, such as increasing use of stream mitigation banking; development of new tools and technologies; different types of process-based restoration; growing recognition of the importance of biological-physical feedbacks in rivers; increasing expectations of water quality improvements from restoration; and more effective communication between practitioners and river scientists.

  19. Large dams and alluvial rivers in the Anthropocene: The impacts of the Garrison and Oahe Dams on the Upper Missouri River

    Science.gov (United States)

    Skalak, Katherine; Benthem, Adam J.; Schenk, Edward R.; Hupp, Cliff R.; Galloway, Joel M.; Nustad, Rochelle A.; Wiche, Gregg J.

    2013-01-01

    The Missouri River has had a long history of anthropogenic modification with considerable impacts on river and riparian ecology, form, and function. During the 20th century, several large dam-building efforts in the basin served the needs for irrigation, flood control, navigation, and the generation of hydroelectric power. The managed flow provided a range of uses, including recreation, fisheries, and habitat. Fifteen dams impound the main stem of the river, with hundreds more on tributaries. Though the effects of dams and reservoirs are well-documented, their impacts have been studied individually, with relatively little attention paid to their interaction along a river corridor. We examine the morphological and sedimentological changes in the Upper Missouri River between the Garrison Dam in ND (operational in 1953) and Oahe Dam in SD (operational in 1959). Through historical aerial photography, stream gage data, and cross sectional surveys, we demonstrate that the influence of the upstream dam is still a major control of river dynamics when the backwater effects of the downstream reservoir begin. In the “Anthropocene”, dams are ubiquitous on large rivers and often occur in series, similar to the Garrison Dam Segment. We propose a conceptual model of how interacting dams might affect river geomorphology, resulting in distinct and recognizable morphologic sequences that we term “Inter-Dam sequence” characteristic of major rivers in the US.

  20. Evidence for Cyclical Fractional Crystallization, Recharge, and Assimilation in Basalts of the Kimama Core, Central Snake River Plain, Idaho: A 5.5-million-year Highlight Reel of Petrogenetic processes in a Mid-Crustal Sill Complex

    Science.gov (United States)

    Potter, Katherine E.; Shervais, John W.; Christiansen, Eric H.; Vetter, Scott K.

    2018-02-01

    -Fe flows are compositionally unrelated to SROT magmas and represent highly fractionated basalt, probably accompanied by crustal assimilation. These evolved lavas may be sourced from the Craters of the Moon/Great Rift system to the northeast. The Kimama drill core is the longest record of geochemical variation in the central Snake River Plain and reinforces the concept of magma processing in a layered complex.

  1. Morphometric and hydro graphic analysis in the hydro graphic basin of the Salsa river in Paraiba South coast of Brasil; Analisis morfometrico y geomorfologico de la cuenca hidrografica del Rio Salsa en la costa Sur del Estado de Paraiba. Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, M.; Nascimento, J.; Furrier, M., E-mail: mariaemanuellaf@gmail.com [Departamento de Geociencias, CCEN, UFPB(Brazil)

    2010-05-15

    This paper aims to extend the knowledge on the geomorphology of the river basin Salsa, located in the town of Con de, Paraiba / Brasil. The purpose of the research was to develop thematic maps and get related morphometric data to evaluate possible influences on tectonics. Were used Map data and satellite photos which allowed morphological and clinograficos analyze.

  2. New data on the chronology of the Vale do Forno sedimentary sequence (Lower Tejo River terrace staircase) and its relevance as a fluvial archive of the Middle Pleistocene in western Iberia

    DEFF Research Database (Denmark)

    Cunha, Pedro; Martins, Antonio; Buylaert, Jan-Pieter

    2017-01-01

    The Vale do Forno archaeological sites (Alpiarça, central Portugal) document the earliest human occupation in the Lower Tejo River, well established in geomorphological and environmental terms, within the Middle Pleistocene. In a staircase of six fluvial terraces, the Palaeolithic sites were found...

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

    Science.gov (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

    2017-04-01

    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 geomorphologi