Sample records for twenty river terrace

  1. Timing and process of river and lake terrace formation in the Kyrgyz Tien Shan (United States)

    Burgette, Reed J.; Weldon, Ray J.; Abdrakhmatov, Kanatbek Ye.; Ormukov, Cholponbek; Owen, Lewis A.; Thompson, Stephen C.


    Well-preserved flights of river and lake terraces traverse an actively deforming rangefront, and form a link between glaciated mountains and a large intermontane lake in the Issyk-Kul basin of the Kyrgyz Tien Shan. We investigated the history and geometry of these lake and river terraces using geologic mapping, surveying, and radiocarbon and terrestrial cosmogenic nuclide dating. A prominent late Pleistocene highstand of the lake occurred over at least the period of 43-25 ka, followed by a period of deep regression and subsequent rise of the lake to the modern sill level in the late Holocene. Major aggradation of the most prominent latest Quaternary river terrace along the Ak-Terek and Barskaun rivers likely started at ∼70-60 ka, coincident to the local last glacial maximum in this region. In contrast to some models of aggradation and incision, the rivers appear to have stayed near the top of the fill for >20 ka, incising subtly below the top of this fill by ∼37 ka, locally. Deep incision likely did not occur until the peak deglaciation in the latest Pleistocene. Older dated terrace surfaces are consistent with one major terrace-forming event per glacial, constant deformation and incision rates, and typical fluvial gradients lower than the modern incising streams. The dating confirms regional terrace correlations for the most prominent late Quaternary terraces, but correlating higher terraces is complicated by spatially varying uplift rates and preferential terrace preservation between basins in the Tien Shan.

  2. Dating and genesis of the upper Weihe River terraces in Longxi basin, China

    Institute of Scientific and Technical Information of China (English)


    Seven terraces along the Weihe River in Longxi basin have been investigated. These terraces all consist of archetypal duality in structure, namely the floodplain deposits and the layer of gravels overlaid by varying thickness of the loess. By resorting to various dating approaches such as palaeomagnetic, optically stimulated luminescenece (OSL), 14C and loess-paleosol sequence, we provide preliminary timing of these seven terraces along upper Weihe River. Analysis on sedimentation characteristics and dating of these terraces showed that seven terraces may be jointly generated by tectonic uplifts and climatic changes. Tectonic uplifts may accommodate initial river incision, and climatic change may be responsible for processes of subsequent channel widening and aggradation. Aggradation normally occurs during glacial periods, in contrast to down-cuttings during transitions from glacial to interglacial period. Moreover, on the basis of the timings and heights of these terraces, we infer that the long-term rate of river incision was determined to be 0.2 m/kyr during the last 870 kyr, which differs from other river incision rates. This discrepancy may reflect spatio-temporal differentiation of tectonic activities in the Qinling orogenic belt during the Pleistocene.

  3. Paragenesia of Quaternary pediments and river terraces on the north piedmont of Wutai Mountains

    Institute of Scientific and Technical Information of China (English)

    ZHANG ShiMin; REN JunJie; NIE GaoZhong


    A study has been made of the paragenetic relations of the pediments and river terraces on the northern piedmont of Wutai Mountains via geomorphologic mapping of 1:10000 scale, and an analysis on the role of tectonic, climatic, and drainage factors in the parageneses. The Quaternary pediments and river terraces on the north piedmont of Wutai Mountains united to constitute six steps of geomorphic surfaces. The episodic uplifting of fault blocks was the dominant factor in the formation of the unified surfaces, however climatic change and drainage diversities led to undulation of the surfaces. The second terrace of Yangyan River (T2) was formed in the last glacial maximum, when the river was in aggradational state. The third to fifth terraces were formed in interglacial stages, when the river was in equilibrium or degradational state. It is inferred that climate had no insignificant effect on the river incision caused by tectonic uplifting. In light of terraces dating, since the Quaternary the Wutai fault-block mountains experienced six rapid uplifting events, and the starting time of the last four events was respectively 1.2, 0.6, 0.13, and 0.02 Ma B.P.

  4. Fluvial terraces of the northwest Iberian lower Miño River.

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    Viveen, W.; Schoorl, J.M.; Veldkamp, A.; Balen, van R.T.; Vidal-Romani, J.R.


    A new fluvial terrace map with a tectonic framework for the northwest Iberian lower Miño River is presented. It is the first integrated map to cover the entire lower, 67-km reach of the Miño River, and to cover both the Spanish and Portuguese side of the river. The map is presented at a scale of 1:2

  5. Terrace aggradation during the 1978 flood on Powder River, Montana, USA (United States)

    Moody, J.A.; Meade, R.H.


    Flood processes no longer actively increase the planform area of terraces. Instead, lateral erosion decreases the area. However, infrequent extreme floods continue episodic aggradation of terraces surfaces. We quantify this type of evolution of terraces by an extreme flood in May 1978 on Powder River in southeastern Montana. Within an 89-km study reach of the river, we (1) determine a sediment budget for each geomorphic feature, (2) interpret the stratigraphy of the newly deposited sediment, and (3) discuss the essential role of vegetation in the depositional processes. Peak flood discharge was about 930??m3 s- 1, which lasted about eight??days. During this time, the flood transported 8.2??million tons of sediment into and 4.5??million tons out of the study reach. The masses of sediment transferred between features or eroded from one feature and redeposited on the same feature exceeded the mass transported out of the reach. The flood inundated the floodplain and some of the remnants of two terraces along the river. Lateral erosion decreased the planform area of the lower of the two terraces (~ 2.7??m above the riverbed) by 3.2% and that of the higher terrace (~ 3.5??m above the riverbed) by 4.1%. However, overbank aggradation, on average, raised the lower terrace by 0.16??m and the higher terrace by 0.063??m. Vegetation controlled the type, thickness, and stratigraphy of the aggradation on terrace surfaces. Two characteristic overbank deposits were common: coarsening-upward sequences and lee dunes. Grass caused the deposition of the coarsening-upward sequences, which had 0.02 to 0.07??m of mud at the base, and in some cases, the deposits coarsened upwards to coarse sand on the top. Lee dunes, composed of fine and very fine sand, were deposited in the wake zone downstream from the trees. The characteristic morphology of the dunes can be used to estimate some flood variables such as suspended-sediment particle size, minimum depth, and critical shear velocity

  6. Vertical slip rates of active faults of southern Albania inferred from river terraces

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    Oswaldo Guzmán


    Full Text Available Fluvial terraces of Shkumbin, Devoll, Osum and Vjosa rivers (southern Albania and northwestern Greece are studied in order to quantify the vertical slip rates of the large active faults of the Dinaric-Albanic-Hellenic Alpine fold belt. The spatial and temporal variations of the incision rates along these rivers were estimated from the geomorphological mapping of the Quaternary sediments, the geometry and the dating of the terraces. Eleven terraces levels were identified in Albania from 68 geochronological ages already published or acquired for this work. The five lower terraces of the four studied rivers are well dated (10 new and 23 already published ages. These terraces are younger than 30 ka and their remnants are numerous. Their restoration allows estimating the regional trend of incision rate and the identification of local shifts. We argue that these shifts are linked to the active tectonics when they coincide with the faults already mapped by previous authors. Vertical slip rates for eight active faults in southern Albania are thus estimated for the last 19 ka and vary from ~0.1 to ~2 mm/a. The Lushnje Tepelene Thrust, that extends more than 120 kilometers, has a throw rate that varies from 0.2 to 0.8 mm/a, whereas the active faults of the extensional domain are segmented but are very active, with throw rates reaching locally 2 mm/a.

  7. River terraces and alluvial fans: The case for an integrated Quaternary fluvial archive (United States)

    Mather, A. E.; Stokes, M.; Whitfield, E.


    The fluvial archive literature is dominated by research on river terraces with appropriate mention of adjacent environments such as lakes. Despite modern sedimentary basins comprising a significant (>88%) volume of distributive fluvial systems, of which alluvial fans (>1 km, archive community. Published literature is used to examine both thematic and geographical based benefits of alluvial fan research that can assist understanding of Quaternary fluvial archives. 3 regional case studies are presented that illustrate the interaction between alluvial fan and river terrace archives at Quaternary time-scales at 3 different stages of landscape evolution. These are i) continuous mountain front alluvial fans interacting with a non incising but laterally eroding axial fluvial system; ii) alluvial fans which transition into fluvial terraces as sedimentary basins shift from net aggradation to net incision and iii) tributary-junction alluvial fans that develop predominantly within incising river valley systems. A simple conceptual model is proposed to summarise the dynamic role of alluvial fans within this landscape context. The alluvial fans act as potential 'buffers' between hillslopes and river terrace records under 'top down' climate-driven high sediment supply and alluvial fan aggradation, and 'couplers' during periods of less sediment (in relation to water) discharge and alluvial fan incision. These dynamics will change with the addition of 'bottom up' controls such as main river incision, which will typically enhance the coupling effect of both systems.

  8. Soil Formation and Taxonomy in Yeşilırmak River Terraces

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    Alper Durak


    Full Text Available In this study, the soils of which parent material is alluvial and formed Yeşilırmak river terraces were investigated. For this purposes four different profiles were excavated in the study area. Then twenty-seven soil samples were taken from horizons of four profiles and their physical and chemical analyses were done for soil taxonomy research. Profile of Kumocagi and Cakil were classified in subgroup as Typic Ustipsamments, Havaalanı and Mera profiles were classified Typic Haplustolls and Typic Argiustolls subgroups respectively. The pH values of soils varied between 7.38-8.41. These soils can be classified as low and highly basic. Most of the soil series had an irregular pH distribution in the profile. The range of carbonate content of the soils was 0.8-25.4%. Although carbonate content of soils showed a very wide range, majority of them can be classified as highly calcareous. In most of soils carbonate content was distributed irregulary in the profile. Organic matter content were between 0.14-6.11% in the soils. Although organic matter contents of the soils changed in a wide range most of them had low organic matter content. Organic matter content was over 4% in the surface horizon of only two profiles. Research result showed that, alluvial parent material, particle size, topograpy and time have different effect on investigation soils.

  9. A mass-balance coupling between river terrace and long profile evolution (United States)

    Wickert, A. D.; Schildgen, T. F.; Tofelde, S.; Savi, S.; Strecker, M. R.; Barnhart, K. R.


    River networks evolve by storing and releasing sediment. In so doing, they produce a measurable record of autogenic and allogenic terraces that are clues to their style of response to changes in climate or tectonics. As a valley network incises, sediment is released from the surrounding hillslopes and is routed downstream at a rate proportional to water supply, sediment supply, channel slope, and grain size. Changes in climate and base-level can perturb this balance, causing aggradation, incision, changes in lateral migration rates, and the formation of terraces (strath, cut, and fill) and packages of valley-fill colluvium. Attribution of terrace formation to external (or allogenic) forcing is possible only when the magnitude and/or duration of the forcing are sufficient to overcome the internal filters in the fluvial system: how much sediment can be stored or released in a particular reach, how much geomorphic work is required to mobilize sediment and/or erode bedrock, and how links between tributaries steer water, sediment, and geomorphic information upstream and downstream. However, the nature of internal filter is not fixed in space or time; each valley segment can be considered as a time-evolving filter that regulates geomorphic response through the topology of the valley network. We simulate river valley network evolution and fluvial terrace formation, with the latter being a key field measurable in geomorphic systems. We model the cross-sectional evolution of river valley segments with TerraPIN (Terraces Put Into Numerics), which uses simple geometric rules to produce realistic river terrace and valley geometries, and can compute volumes of sediment stored in and released from the valley. This sediment is supplied as a source or sink to a linked network of one-dimensional river long profile models. These allow the river to aggrade, incise, and transport sediment, and feed back into the cross-sectional models. Together, this set of models is able to overcome

  10. Multi-scale tectonic controls on fluvial terrace formation in a glacioeustatically-dominated river system: inference from the lower Min¿o terrace record

    NARCIS (Netherlands)

    Viveen, W.


      The general aim of this thesis is to untangle the interacting effects of climate, glacioeustacy, and regional, and local tectonics on fluvial terrace formation. The NW Iberian lower Miño River valley was chosen as a study site, because for this region, a very detailed, long-term, clim

  11. Himalayan River Terraces as A Landscape Response to Quaternary Summer Monsoon Variability (United States)

    Jonell, T. N.; Clift, P. D.


    In order to interpret marine sedimentary archives as records of the erosional response to Asian monsoon variability, we must first recognize how transport processes affect the storage and release of sediment to the ocean. River terraces, such as found in the Greater Himalaya, provide a pivotal role in the source-to-sink story, because this is where sediment storage occurs and is likely modulated. We investigate the role that climate plays in controlling erosion and sediment flux to the Indus delta and fan by looking at the Indus River system, which is dominated by the strong forcing of the Asian monsoon, as well as winter Westerly winds. Paleoceanographic, speleothem, and lacustrine records indicate that summer monsoon intensity was strong from 29 to 37 ka, decreased after that time until ~16 ka, reached maximum intensity from 8 to 10 ka, and then weakened until ~3 ka. Some lacustrine records, however, indicate a more complex pattern of monsoon variability in the Greater Himalaya, which contrasts with monsoonal forcing in central India. This disagreement suggests that floodplains of major river systems may not experience the same climatic conditions as their mountain sources, resulting in contrasting landscape responses to climate change. High altitude river valleys, at least north ofthe Greater Himalaya, appear to be sensitive to monsoon strength because they lie on the periphery of the present rainfall maximum, in the Himalayan rain shadow. These steep river valleys may be affected by landslide damming during periods of increase moisture transport and strong monsoonal precipitation, where damming provides sediment storage through valley-filling and later sediment release through gradual incision or dam-bursting. The Zanskar River, a major tributary to the upper Indus River, provides a record of the erosional response of mountain river valleys to these extreme phases through river terracing. New OSL ages from alluvial terraces indicate reworking of sediment and

  12. Comparison of Methods to Map and Measure River Terraces using High-Resolution Airborne LiDAR Data (United States)

    Hopkins, A. J.; Snyder, N. P.


    Fluvial terraces are important recorders of land-use, climate, and tectonic history that form in both erosional and depositional landscapes and consist of a flat surface bounded by valley walls and a steep-sloping scarp adjacent to the river channel. Combining these defining characteristics with high-resolution digital elevation models (DEMs) derived from airborne light detection and ranging (lidar) surveys, several methods have been developed to identify and map terraces. The goals of this research are to compare some of these existing techniques and develop an objective approach to map terraces over entire watersheds using lidar DEMs. Additionally, we aim to quantify the thickness and volume of fill terrace deposits. Our preliminary application is to the Sheepscot River watershed, Maine, where strath and fill terraces are present and record Pleistocene deglaciation, Holocene eustatic forcing, and Anthropocene land-use change. We identify terraces along the longitudinal profile using an algorithm developed by Finnegan and Balco (2013), that computes the elevation frequency distribution at regularly spaced cross-sections normal to the channel. Next, we delineate terrace spatial extent using three separate methodologies: (1) image processing using Matlab, (2) feature classification algorithms developed by Wood (1996), and (3) image interpretation using manually placed points on known terraces to construct interpolated surfaces (Walter and Merritts, 2008). Lastly, we determine the thickness and volume of fill terrace sediments by subtracting an interpolated, adjacent water surface elevation from the defined terrace points. We compare our LiDAR-based results with field mapping, stratigraphic columns of terrace landforms, and ground penetrating radar over terrace surfaces. These findings suggest powerful new ways to rapidly analyze landscape history over large regions using high-resolution lidar DEMs, with less reliance on detailed and costly field data collection.

  13. Impact of halite dissolution subsidence on Quaternary fluvial terrace development: Case study of the Huerva River, Ebro Basin, NE Spain (United States)

    Guerrero, Jesús; Gutiérrez, Francisco; Lucha, Pedro


    This paper analyses the control of evaporite dissolution subsidence on the evolution of the lower 30 km-long reach of the Huerva River up to its confluence with the Ebro River. In the study area the Huerva River flows across different interfingered lithofacies of the subhorizontally lying Ebro Basin fill: (1) shales and sandstones upstream of Cadrete; (2) evaporites dominated by gypsum between Cadrete and Cuarte; (3) gypsum with glauberite and halite units in the subsurface downstream of Cuarte. The halite shows a marked downvalley increase in thickness. Twelve terrace levels and seven pediment levels correlative to some of the terraces have been mapped in the studied area. Upstream of Cadrete, the terrace deposits, with a relatively constant thickness less than 4 m and overlying unsoluble bedrock, remain undeformed. Between Cadrete and Cuarte the deposits of some terraces show local thickening ( 60 m-thick terrace alluvium that fills a 5 km-long trough generated by synsedimentary subsidence phenomena caused primarily by the interstratal dissolution of halite. The older terraces (T1 to T4) show slight thickening (> 18 m) and locally truncate paleocollapse structures ascribed to the interstratal karstification of halite beds. The intermediate terraces (T5 to T7) correspond to degradation surfaces that grade downstream of Cuarte into aggradation flights underlain by the abruptly thickened deposits that fill this 5 km-long dissolution trough. Subsidence migrated episodically downstream during the generation of these terraces and the subsidence/aggradation rate was probably large enough to induce a base-level drop and knickpoint migration upstream generating strath terraces with convergent longitudinal profiles. The sedimentological changes that show the thickened terrace deposits in the subsidence area (high proportion of overbank fines (> 60%) including palustrine facies, gravel channels with lower width/depth ratio, multiple fining-upward cycles, decrease in the

  14. Late Quaternary stream piracy and strath terrace formation along the Belle Fourche and lower Cheyenne Rivers, South Dakota and Wyoming (United States)

    Stamm, John F.; Hendricks, Robert R.; Sawyer, J. Foster; Mahan, Shannon; Zaprowski, Brent J.; Geibel, Nicholas M.; Azzolini, David C.


    Stream piracy substantially affected the geomorphic evolution of the Missouri River watershed and drainages within, including the Little Missouri, Cheyenne, Belle Fourche, Bad, and White Rivers. The ancestral Cheyenne River eroded headward in an annular pattern around the eastern and southern Black Hills and pirated the headwaters of the ancestral Bad and White Rivers after ~ 660 ka. The headwaters of the ancestral Little Missouri River were pirated by the ancestral Belle Fourche River, a tributary to the Cheyenne River that currently drains much of the northern Black Hills. Optically stimulated luminescence (OSL) dating techniques were used to estimate the timing of this piracy event at ~ 22–21 ka. The geomorphic evolution of the Cheyenne and Belle Fourche Rivers is also expressed by regionally recognized strath terraces that include (from oldest to youngest) the Sturgis, Bear Butte, and Farmingdale terraces. Radiocarbon and OSL dates from fluvial deposits on these terraces indicate incision to the level of the Bear Butte terrace by ~ 63 ka, incision to the level of the Farmingdale terrace at ~ 40 ka, and incision to the level of the modern channel after ~ 12–9 ka. Similar dates of terrace incision have been reported for the Laramie and Wind River Ranges. Hypothesized causes of incision are the onset of colder climate during the middle Wisconsinan and the transition to the full-glacial climate of the late-Wisconsinan/Pinedale glaciation. Incision during the Holocene of the lower Cheyenne River is as much as ~ 80 m and is 3 to 4 times the magnitude of incision at ~ 63 ka and ~ 40 ka. The magnitude of incision during the Holocene might be due to a combined effect of three geomorphic processes acting in concert: glacial isostatic rebound in lower reaches (~ 40 m), a change from glacial to interglacial climate, and adjustments to increased watershed area resulting from piracy of the ancestral headwaters of the Little Missouri River.

  15. Late Quaternary stream piracy and strath terrace formation along the Belle Fourche and lower Cheyenne Rivers, South Dakota and Wyoming (United States)

    Stamm, John F.; Hendricks, Robert R.; Sawyer, J. Foster; Mahan, Shannon A.; Zaprowski, Brent J.; Geibel, Nicholas M.; Azzolini, David C.


    Stream piracy substantially affected the geomorphic evolution of the Missouri River watershed and drainages within, including the Little Missouri, Cheyenne, Belle Fourche, Bad, and White Rivers. The ancestral Cheyenne River eroded headward in an annular pattern around the eastern and southern Black Hills and pirated the headwaters of the ancestral Bad and White Rivers after ~ 660 ka. The headwaters of the ancestral Little Missouri River were pirated by the ancestral Belle Fourche River, a tributary to the Cheyenne River that currently drains much of the northern Black Hills. Optically stimulated luminescence (OSL) dating techniques were used to estimate the timing of this piracy event at ~ 22-21 ka. The geomorphic evolution of the Cheyenne and Belle Fourche Rivers is also expressed by regionally recognized strath terraces that include (from oldest to youngest) the Sturgis, Bear Butte, and Farmingdale terraces. Radiocarbon and OSL dates from fluvial deposits on these terraces indicate incision to the level of the Bear Butte terrace by ~ 63 ka, incision to the level of the Farmingdale terrace at ~ 40 ka, and incision to the level of the modern channel after ~ 12-9 ka. Similar dates of terrace incision have been reported for the Laramie and Wind River Ranges. Hypothesized causes of incision are the onset of colder climate during the middle Wisconsinan and the transition to the full-glacial climate of the late-Wisconsinan/Pinedale glaciation. Incision during the Holocene of the lower Cheyenne River is as much as ~ 80 m and is 3 to 4 times the magnitude of incision at ~ 63 ka and ~ 40 ka. The magnitude of incision during the Holocene might be due to a combined effect of three geomorphic processes acting in concert: glacial isostatic rebound in lower reaches (~ 40 m), a change from glacial to interglacial climate, and adjustments to increased watershed area resulting from piracy of the ancestral headwaters of the Little Missouri River.

  16. Contrasting terrace systems of the lower Moulouya river as indicator of crustal deformation in NE Morocco (United States)

    Rixhon, Gilles; Bartz, Melanie; El Ouahabi, Meriam; Szemkus, Nina; Brückner, Helmut


    The Moulouya river has the largest catchment in Morocco and drains an area characterized by active crustal deformation during the Late Cenozoic due to the N-S convergence between the African and Eurasian plates. As yet, its Pleistocene terrace sequence remains poorly documented. Our study focuses on the lowermost reach of the river in north-eastern Morocco, which drains the Zebra-Triffa sedimentary basin directly upstream of the estuary. New field observations, measurements and sedimentological data reveal contrasting fluvial environments on each side of a newly identified, W-E striking thrust zone disrupting the sedimentary basin. On the one hand, long-lasting fluvial aggradation, materialized by 37 m-thick stacked terraces, has occurred in the footwall of the thrust. On the other hand, the hanging wall is characterized by a well-preserved terrace staircase, with three Pleistocene terrace levels. Whilst the identification of this thrust zone question some previous interpretations about the local (hydro-)geology, it is consistent with the statement that most of the Plio-Quaternary deformation in the eastern Rif mountains has concentrated in this region of Morocco. Our new data and interpretations also agree with morphometric indicators showing that the whole Moulouya catchment is at desequilibrium state (i.e. several knickzones in its longitudinal profile), showing several knickzones in its longitudinal profile, is at disequilibrium state. We also suggest that the knickzone in the Beni Snassen gorge, located directly upstream of the Zebra-Triffa sedimentary basin, could (partly) result from a transient fluvial reaction to Late Cenozoic thrusting activity and correlated uplift in the hanging wall.

  17. Mapping of buried river terraces on the Kopite Hill, Gerecse Mts., Northern Hungary (United States)

    Kiss, Dániel; Szőts, Gergely K.; Ruszák, Zsófia; Bereczki, László; Molnár, Gábor; Timár, Gábor; Fodor, László; Csillag, Gábor; Lantos, Zoltán


    The Gerecse Mountains is a part of the Transdanubian Mountain Range. The Kopite Hill located on the northern part of the Gerecse Mountains, on the southern side of the Danube and the Hungarian-Slovakian border. At the southern side of the Danube (100 m a.s.l.) a 290 m high hill of Pannonian (Miocene) marine clay, silt and sand can be found. These Pannonian strata are covered with Pliocene-Pleistocene alluvial sediments, loess and travertine. On the Kopite Hill some small outcrops of gravel can be found, which thought to be one of the highest river terrace levels, but it is not proved. To the northwest there is 270-300 m high plateau of the 'Roman-quarry' with a formerly mined travertine-body. According to a recent discovery a Mammoth-tooth and other fossils of mammals were found there, which were dated and correlated. Because the travertine body is at lower height than the assumed terrace level, a maximum rate of uplift can be given. The aim of our fieldwork was to determine the geometry of gravel strata and the connections between the distinct outcrops and the travertine body. We used multielectrode measurements with supplementary VES measurements. We found that on the north side of Kopite Hill and to south from the Roman-quarry there is an almost horizontal 300*100 m large, 8-13 m thick pebble stratum. Direct connection to the travertine body is not possible, because there is a few tens of meters gap between the two bodies, filled with loess. We assume the gravel stratum with its 258-252 m height (gently dips to the south) is a river terrace. On the southest point of this river terrace the thickness of the gravel suddenly increases to 22 meters. To the south there are also some gravel outcrops, and also a drill which suggest that the bottom of these gravels are higher on higher level, about at 265 m a.s.l.. We interpret this phenomenon as a higher terrace level. With the use of geoelectrical methods we could determine the geometry of gravel stratum on the Kopite

  18. Comparison of River Terraces in the Middle Reach Valleys of the Yellow River and Analysis on the Multi-Gradational Features of Tectonism in the Formation of Terrace Series

    Institute of Scientific and Technical Information of China (English)

    Xing Chengqi; Ding Guoyu; Lu Yanchou; Shen Xuhui; Tian Qinjian; Yin Gongming; Chai Zhizhang; Wei Kaibo


    Where the Yellow River flows through the Haiyuan-Tongxin arc-form tectonic region on thenortheastern side of the Qinghai-Xizang (Tibet) Plateau, as many as 10 ~ 21 basis and erosionterraces have been produced, among which the biggest altitude above river level is 401m andthe formation age of the highest terrace is 1.57 Ma B.P. Based on comparative analysis of theYellow River terraces located separately in the Mijiashan mountain, the Chemuxia gorge, theHeishanxia gorge and the other river terraces in the vast extent of the northern part of China,it has been found that the tectonic processes resulting in the formation of the terrace series isone of multi-gradational features, i.e., a terrace series can include the various terracesproduced by tectonic uplifts of different scopes or scales and different ranks. The Yellow Riverterrace series in the study region can be divided into three grades. Among them, in the firstgrade there are 6 terraces which were formed separately at the same time in the vast extent ofthe northern part of China and represent the number and magnitude of uplift of the Qinghai-Xizang Plateau since 1.6 Ma B. P.; in the second grade there are 5 terraces which wereseparately and simultaneously developed within the Haiyuan-Tianjingshan tectonic region andrepresent the number and magnitude of uplift of this tectonic region itself since 1.6Ma B.P.;in the third grade there are 10 terraces which developed on the eastern slope of the Mijiashanmountain and represent the number and amplitude of uplift of the Haiyuan tectonic belt itselfsince 1. 6Ma B.P. Comparison of the terrace ages with loess-paleosoil sequence has also showedthat the first grade terraces reflecting the vast scope uplifts of the Qinghai-Xizang Plateau arevery comparable with climatic changes and their formation ages all correspond to theinterglacial epochs during which paleosoils were formed. This implies that the vast extenttectonic uplifts resulting in river down-cutting are closely

  19. Holocene fluvial terraces in the Gangkou River Basin of Hengchun Peninsula, Taiwan: implications for sea-level and tectonic controls (United States)

    Chen, Jia-Hong; Chyi, Shyh-Jeng; Ho, Lih-Der; Jen, Chia-Hung; Yen, Jiun-Yee; Lüthgens, Christopher


    The Gangkou River basin is the largest basin in the eastern Hengchun Peninsula, which is the most latest emerged region of the Taiwan orogen. The width of the active channel of Gangkou River is narrow but the valleys from middle to downstream are remarkably wide, which indicates the features of underfit stream. Based on the 14C dates of buried tree trunk and terrace sediments, the preliminary model for the geomorphic evolution of Gangkou River is proposed as: Stage I: The wide spread fine-grained sediments of more than 30-meter-thick was found in the downstream area of drainage basin. The large-scale aggradation event was formed between 12000 to 7000 yr BP in response to the rapid sea-level rise during the late Pleistocene and early Holocene. Stage II: The 15 to 20-meter-high terraces of Gangkou River were formed by the incision and lateral erosion between 7000 to 400 yr BP. The 14C dates of marine terraces, beach rocks and sand dune near the estuary also indicate this erosional stage which could be related to the mid-Holocene climatic shift, tectonic uplift and the stabilized sea-level. Stage III: The 3 to 5-meter-high terraces were formed around 400 yr BP which indicated the low incision rate and the modern fluvial processes. The uplift rates are estimated by the height of river and marine terraces as 1.0 to 1.5 and 1.5 to 2.5 mm/yr respectively. The results indicate the low uplift rate maybe contributed to the underfit stream feature, and the fluvial terraces are responding to sea-level, tectonic and climate controls with different timescale in the Gangkou River. The low uplift rate found in the Gangkou River contradicted to the idea of high tectonic uplift rate in Taiwan.

  20. Records of human occupation from Pleistocene river terrace and aeolian sediments in the Arneiro depression (Lower Tejo River, central eastern Portugal)

    DEFF Research Database (Denmark)

    Cunha, Pedro P.; Almeida, Nelson A.C.; Aubry, Thierry


    In the uppermost reach of the Lower Tejo River (eastern central Portugal), where the river crosses two quartzite ridges that separate the Ródão (upstream) and Arneiro (downstream) depressions, Palaeolithic artefacts have been recovered from three lower river terrace levels and a cover unit of aeo...

  1. Differential uplift and incision of the Yakima River terraces, central Washington State (United States)

    Bender, Adrian M; Amos, Colin B.; Bierman, Paul R.; Rood, Dylan; Staisch, Lydia; Kelsey, Harvey M.; Sherrod, Brian


    The fault-related Yakima folds deform Miocene basalts and younger deposits of the Columbia Plateau in central Washington State. Geodesy implies ~2 mm/yr of NNE directed shortening across the folds, but until now the distribution and rates of Quaternary deformation among individual structures has been unclear. South of Ellensburg, Washington, the Yakima River cuts a ~600 m deep canyon across several Yakima folds, preserving gravel-mantled strath terraces that record progressive bedrock incision and related rock uplift. Here we integrate cosmogenic isochron burial dating of the strath terrace gravels with lidar analysis and field mapping to quantify rates of Quaternary differential incision and rock uplift across two folds transected by the Yakima River: Manastash and Umtanum Ridge. Isochron burial ages from in situ produced 26Al and 10Be at seven sites across the folds date episodes of strath terrace formation over the past ~2.9 Ma. Average bedrock incision rates across the Manastash (~88 m/Myr) and Umtanum Ridge (~46 m/Myr) anticlines are roughly 4 to 8 times higher than rates in the intervening syncline (~14 m/Myr) and outside the canyon (~10 m/Myr). These contrasting rates demonstrate differential bedrock incision driven by ongoing Quaternary rock uplift across the folds at rates corresponding to ~0.13 and ~0.06 mm/yr shortening across postulated master faults dipping 30 ± 10°S beneath the Manastash and Umtanum Ridge anticlines, respectively. The reported Quaternary shortening across the anticlines accounts for ~10% of the ~2 mm/yr geodetic budget, suggesting that other Yakima structures actively accommodate the remaining contemporary deformation.

  2. River terrace development in the NE Mediterranean region (Syria and Turkey): Patterns in relation to crustal type (United States)

    Bridgland, David R.; Demir, Tuncer; Seyrek, Ali; Daoud, Mohamad; Abou Romieh, Mohammad; Westaway, Rob


    It is widely recognized that the optimal development of river terraces globally has been in the temperate latitudes, with NW and Central Europe being areas of particular importance for the preservation of such archives of Quaternary environmental change. There is also a growing consensus that the principal drivers of terrace formation have been climatic fluctuation against a background of progressive (but variable) uplift. Nonetheless river terraces are widely preserved in the Mediterranean region, where they have often been attributed to the effects of neotectonic activity, with a continuing debate about the relative significance of fluctuating temperature (glacials-interglacials) and precipitation (pluvials-interpluvials). Research in Syria and southern-central Turkey (specifically in the valleys of the Tigris and Ceyhan in Turkey, the Kebir in Syria and the trans-border rivers Orontes and Euphrates) has underlined the importance of uplift rates in dictating the preservation pattern of fluvial archives and has revealed different patterns that can be related to crustal type. The NE Mediterranean coastal region has experienced unusually rapid uplift in the Late Quaternary. The relation between the Kebir terraces and the staircase of interglacial raised beaches preserved along the Mediterranean coastline of NW Syria reinforces previous conclusions that the emplacement of the fluvial terrace deposits in the Mediterranean has occurred during colder climatic episodes.

  3. Multiple climatic cycles imprinted on regional uplift-controlled fluvial terraces in the lower Yalong River and Anning River, SE Tibetan Plateau (United States)

    He, Zexin; Zhang, Xujiao; Bao, Shuyan; Qiao, Yansong; Sheng, Yuying; Liu, Xiaotong; He, Xiangli; Yang, Xingchen; Zhao, Junxiang; Liu, Ru; Lu, Chunyu


    The development of fluvial systems on the southeastern margin of the Tibetan Plateau is linked to significant and rapid late Cenozoic uplift. The relatively complete fluvial terrace sequence preserved along the Yalong River valley and that of its tributary, the Anning River, provides an excellent archive for studying the development of terraces in rapidly uplifting mountainous areas. This study reveals that terrace development is predominantly controlled by multiscale climate cycles and long-term uplift, as shown by terrace dating, sedimentary characteristics, and incision rates. At least six alluvial terrace units were identified in 20 transverse sections through the terraces along about a 600 km length of river and were dated using Electron Spin Resonance (ESR) and Optically Stimulated Luminescence (OSL). The climatostratigraphic positions of the terrace deposits and their respective age constraints suggest that fluvial aggradation was concentrated during Marine Isotope Stages (MIS) 32, 22, 18, 4, 2, and the Younger Dryas (YD) and that incision occurred during the succeeding cold-to-warm transitions. The changes in fluvial style marked by terraces 6, 5, and 4 predominantly occurred in synchrony with the 100-ka Milankovitch climate cycles, while terraces 3 and 2 were controlled by the obliquity-driven 41-ka climate cycles. Finally, the aggradation of terrace T1 occurred in response to the YD stadial. During the intervening time between 0.72 and 0.063 Ma, terraces either did not form or were not preserved, which may suggest that uplift rates varied through time and influenced terrace formation/preservation. The progressive valley incision recorded by these fluvial terraces cannot be entirely explained by climate cycling alone. Temporal and spatial variations in incision rates indicate that the continuing long-term incision has been driven by uplift. The temporal distribution of the incision rates reveals two rapidly uplifting stages in the southeastern Tibetan

  4. Single-grain and multi-grain OSL dating of river terrace sediments in the Tabernas Basin, SE Spain

    DEFF Research Database (Denmark)

    Geach, M.R.; Thomsen, Kristina Jørkov; Buylaert, Jan-Pieter


    River terraces represent important records of landscape response to e.g. base-level change and tectonicmovement. Both these driving forces are important in the southern Iberian Peninsula. In this study,Optically Stimulated Luminescence (OSL) dating was used to date two principal river terraces...... in theTabernas Basin, SE Spain. A total of 23 samples was collected from the fluvial terraces for dating usingquartz OSL. Sixteen of the samples could not be dated because of low saturation levels (e.g. typical2xD0 ... usingboth multi-grain and single-grain analysis. Single grain results show that: (i) measurements from multigrainaliquots overestimate ages by up to ~ 4 ka for modern analogues and young samples (

  5. Single-grain and multi-grain OSL dating of river terrace sediments in the Tabernas Basin, SE Spain

    DEFF Research Database (Denmark)

    Geach, M.R.; Thomsen, Kristina Jørkov; Buylaert, Jan-Pieter


    River terraces represent important records of landscape response to e.g. base-level change and tectonicmovement. Both these driving forces are important in the southern Iberian Peninsula. In this study,Optically Stimulated Luminescence (OSL) dating was used to date two principal river terraces...... in theTabernas Basin, SE Spain. A total of 23 samples was collected from the fluvial terraces for dating usingquartz OSL. Sixteen of the samples could not be dated because of low saturation levels (e.g. typical2xD0 ... usingboth multi-grain and single-grain analysis. Single grain results show that: (i) measurements from multigrainaliquots overestimate ages by up to ~ 4 ka for modern analogues and young samples (

  6. Statistical analyses of soil properties on a quaternary terrace sequence in the upper sava river valley, Slovenia, Yugoslavia (United States)

    Vidic, N.; Pavich, M.; Lobnik, F.


    Alpine glaciations, climatic changes and tectonic movements have created a Quaternary sequence of gravely carbonate sediments in the upper Sava River Valley, Slovenia, Yugoslavia. The names for terraces, assigned in this model, Gu??nz, Mindel, Riss and Wu??rm in order of decreasing age, are used as morphostratigraphic terms. Soil chronosequence on the terraces was examined to evaluate which soil properties are time dependent and can be used to help constrain the ages of glaciofluvial sedimentation. Soil thickness, thickness of Bt horizons, amount and continuity of clay coatings and amount of Fe and Me concretions increase with soil age. The main source of variability consists of solutions of carbonate, leaching of basic cations and acidification of soils, which are time dependent and increase with the age of soils. The second source of variability is the content of organic matter, which is less time dependent, but varies more within soil profiles. Textural changes are significant, presented by solution of carbonate pebbles and sand, and formation is silt loam matrix, which with age becomes finer, with clay loam or clayey texture. The oldest, Gu??nz, terrace shows slight deviation from general progressive trends of changes of soil properties with time. The hypothesis of single versus multiple depositional periods of deposition was tested with one-way analysis of variance (ANOVA) on a staggered, nested hierarchical sampling design on a terrace of largest extent and greatest gravel volume, the Wu??rm terrace. The variability of soil properties is generally higher within subareas than between areas of the terrace, except for the soil thickness. Observed differences in soil thickness between the areas of the terrace could be due to multiple periods of gravel deposition, or to the initial differences of texture of the deposits. ?? 1991.

  7. Incision and uplift patterns along the Yellow River from fluvial terrace dating in northeastern Tibet: implications for plateau building (United States)

    van der Woerd, J.; Perrineau, A.; Gaudemer, Y.; Liu, J.; Pik, R.; Tapponnier, P.; Thuizat, R.; Zheng, R.


    Unraveling river development and tectonics allow constrain key processes of landscape evolution and continental plateau building. In northeastern Tibet, the Yellow River escapes from the plateau towards the northeast crossing 2 of the largest strike-slip faults of Tibet and no less than 5 NW-SE striking, actively growing ranges and intervening basins. Across the Kunlun and Haiyuan strike-slip faults the Yellow River course show large deflections of about 80-90 km and 50-100 km, respectively. Despite undetermined total geological offsets along the faults, these deflections are best interpreted as tectonic offsets of comparable amounts. In addition, cosmogenic isotope dating of Yellow River terraces abandoned on the eastern flank of the Mijia Shan push-up in a bend of the Haiyuan fault allow constrain an uplift-rate of about 1 mm/yr implying onset of deformation of the push-up about 1 Ma. Between the strike-slip faults and upstream of Lanzhou, Plio-Quaternary deposits and fluvial terraces testify to a previous phase of aggradation. In particular, the high and flat paleo-base levels (3200 m) of the Gonghe and Guide basins, together with that of the Qinghai lake basin imply the existence of a greater parent basin dammed by uplift of the Riyue Shan, prior to, or during the growth of the upper Yellow River catchment. Today, the river has cut a 500 km-long gorge, eroding much of the 1000 m-thick Quaternary sediment pile, and incising steep-walled canyons across the ranges. The corresponding base level drop has left a spectacular flight of seven major terrace levels across the 50 km-wide Gonghe basin, with additional strath terraces abrading the Waliguan bedrock. The main terraces slope to the northeast, sub-parallel to the Yellow River course. In contrast, the cobble-paved bedrock straths north and south of the EW-trending Longyang canyon slope westwards, opposite to the river gradient, attesting to recent tectonic uplift and tilting of the Waliguan range. Cosmogenic

  8. Insights into the Quaternary tectonics of the Yellowstone hotspot from a terrace record along the Hoback and Snake rivers. (United States)

    Bufe, A.; Pederson, J. L.; Tuzlak, D.


    One of Earth's largest active supervolcanos and one of the most dynamically deforming areas in North America is located above the Yellowstone mantle plume. A pulse of dynamically supported uplift and extension of the upper crust has been moving northeastward as the North American plate migrated across the hotspot. This pules of uplift is complicated by subsidence of the Snake River Plain in the wake of the plume, due to a combination of crustal loading by intrusive and extrusive magmas, and by densification of igneous and volcanic rocks. Understanding the geodynamics as well as the seismic hazard of this region relies on studying the distribution and timing of active uplift, subsidence, and faulting across timescales. Here, we present preliminary results from a study of river terraces along the Hoback and upper Snake rivers that flow from the flanks of the Yellowstone plateau into the subsiding Snake River Plain. Combining terrace surveys with optically stimulated luminescence ages, we calculate incision rates of 0.1 - 0.3 mm/y along the deeply incised canyons of the Hoback and Snake rivers upstream of Alpine, WY. Rather than steadily decreasing away from the Yellowstone plume-head, the pattern of incision rates seems to be mostly affected by the distribution of normal faults - including the Alpine section of the Grand Valley Fault that has been reported to be inactive throughout the Quaternary. Downstream of Alpine and approaching the Snake River Plain, late Quaternary fill-terraces show much slower incision rates which might be consistent with a broad flexure of the region toward the subsiding Snake River Plain. Future studies of the Snake and Hoback rivers and additional streams around the Yellowstone hotspot will further illuminate the pattern of late Quaternary uplift in the region.

  9. Dating of river terraces along Lefthand Creek, western High Plains, Colorado, reveals punctuated incision (United States)

    Foster, Melissa A.; Anderson, Robert S.; Gray, Harrison J.; Mahan, Shannon


    The response of erosional landscapes to Quaternary climate oscillations is recorded in fluvial terraces whose quantitative interpretation requires numerical ages. We investigate gravel-capped strath terraces along the western edge of Colorado's High Plains to constrain the incision history of this shale-dominated landscape. We use ¹⁰Be and ²⁶Al cosmogenic radionuclides (CRNs), optically stimulated luminescence (OSL), and thermally transferred OSL (TT-OSL) to date three strath terraces, all beveled in shale bedrock and then deposited upon by Lefthand Creek, which drains the crystalline core of the Front Range. Our study reveals: (i) a long history (hundreds of thousands of years) of fluvial occupation of the second highest terrace, T2 (Table Mountain), with fluvial abandonment at 92 ± 3 ka; (ii) a brief occupation of a narrow and spatially confined terrace, T3, at 98 ± 7 ka; and (iii) a 10–25 thousand year period of cutting and fluvial occupation of a lower terrace, T4, marked by the deposition of a lower alluvial unit between 59 and 68 ka, followed by deposition of an upper alluvial package at 40 ± 3 ka. In conjunction with other recent CRN studies of strath terraces along the Colorado Front Range (Riihimaki et al., 2006; Dühnforth et al., 2012), our data reveal that long periods of lateral planation and fluvial occupation of strath terraces, sometimes lasting several glacial-interglacial cycles, are punctuated by brief episodes of rapid vertical bedrock incision. These data call into question what a singular terrace age represents, as the strath may be cut at one time (its cutting-age) and the terrace surface may be abandoned at a much later time (its abandonment age), and challenge models of strath terraces that appeal to simple pacing by the glacial-interglacial cycles.

  10. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the Cimarron River from Freedom to Guthrie in northwestern Oklahoma (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital polygons of a constant recharge rate for the alluvial and terrace deposits along the Cimarron River from Freedom to Guthrie in...

  11. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the Cimarron River from Freedom to Guthrie in northwestern Oklahoma (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital polygons of constant hydraulic conductivity values for the alluvial and terrace deposits along the Cimarron River from Freedom to...

  12. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the North Canadian River from Canton Lake to Lake Overholser in central Oklahoma (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital aquifer boundaries for the alluvial and terrace deposits along the North Canadian River from Canton Lake to Lake Overholser in...

  13. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the North Canadian River from Canton Lake to Lake Overholser in central Oklahoma (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital water-level elevation contours for the alluvial and terrace deposits along the North Canadian River from Canton Lake to Lake...

  14. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the Cimarron River from Freedom to Guthrie in northwestern Oklahoma (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital water-level elevation contours for the alluvial and terrace deposits along the Cimarron River in northwestern Oklahoma during...

  15. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the North Canadian River from Canton Lake to Lake Overholser in central Oklahoma (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital polygons of a constant recharge value for the alluvial and terrace deposits along the North Canadian River from Canton Lake to Lake...

  16. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the Cimarron River from Freedom to Guthrie in northwestern Oklahoma (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital aquifer boundaries for the alluvial and terrace deposits along the Cimarron River from Freedom to Guthrie in northwestern Oklahoma....

  17. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the North Canadian River from Canton Lake to Lake Overholser in central Oklahoma (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital polygons of a constant hydraulic conductivity value for the alluvial and terrace deposits along the North Canadian River from...

  18. Soil development on Late Quaternary river terraces in a high montane valley in Bhutan, Eastern Himalayas

    NARCIS (Netherlands)

    Tshering Dorji,; Caspari, T.; Bäumler, R.; Veldkamp, A.; Jongmans, A.G.; Kado Tshering,; Tsheten Dorji,; Baillie, I.


    We examined the geochemistry and micromorphology of the soils on a suite of morphologically well-defined and visually distinct fluvial terraces, up to 40 m elevation above the current riverbed, at Thangbi in the upper Bumthang Valley, Bhutan. The alluvia forming each of the terraces are lithological

  19. Investigating fluvial features with electrical resistivity imaging and ground-penetrating radar: The Guadalquivir River terrace (Jaen, Southern Spain) (United States)

    Rey, J.; Martínez, J.; Hidalgo, M. C.


    A geophysical survey has been conducted on the lowest terrace levels and the present day floodplain of the current course of the Guadalquivir River, passing through the province of Jaen (Spain), using two techniques: electrical resistivity imaging (ERI) and ground-penetrating radar (GPR). Three areas have been selected. In one of these sectors (Los Barrios) there is an old quarry where there are excellent outcrops that allow for the calibration of the survey techniques. Facies associations on these outcrops are typical of meandering rivers with sequences of channel fills, lateral accretion of point-bars and floodplain facies. The usefulness of the two methods is analysed and compared as a support for stratigraphic and sedimentological studies. The geometry and lithofacies of subsurface deposits were characterised using ERI and compared with field observations. A total of 5 electrical resistivity imaging profiles were obtained. The changes in electric resistivity highlight granulometric differences in terrace sediments. This technique can thus be used to identify the morphology of these bodies, the lithofacies (silt, sand or gravel) and buried channel pattern. In addition, 16 GPR profiles using 100 and 250 MHz antennas were acquired, indicating terrace morphology and the filling of the sedimentary bodies in a more detailed manner than in ERI. The study thus allows for inferring the existence of channel migration, the lateral accretion of point bars and the presence of vertical accretion deposits attributable to the floodplains.

  20. Processes of Terrace Formation on the Piedmont of the Santa Cruz River Valley During Quaternary Time, Green Valley-Tubac Area, Southeastern Arizona (United States)

    Lindsey, David A.; Van Gosen, Bradley S.


    In this report we describe a series of stepped Quaternary terraces on some piedmont tributaries of the Santa Cruz River valley in southeastern Arizona. These terraces began to form in early Pleistocene time, after major basin-and-range faulting ceased, with lateral planation of basin fill and deposition of thin fans of alluvium. At the end of this cycle of erosion and deposition, tributaries of the Santa Cruz River began the process of dissection and terrace formation that continues to the present. Vertical cutting alternated with periods of equilibrium, during which streams cut laterally and left thin deposits of channel fill. The distribution of terraces was mapped and compiled with adjacent mapping to produce a regional picture of piedmont stream history in the middle part of the Santa Cruz River valley. For selected tributaries, the thickness of terrace fill was measured, particle size and lithology of gravel were determined, and sedimentary features were photographed and described. Mapping of terrace stratigraphy revealed that on two tributaries, Madera Canyon Wash and Montosa Canyon Wash, stream piracy has played an important role in piedmont landscape development. On two other tributaries, Cottonwood Canyon Wash and Josephine Canyon Wash, rapid downcutting preempted piracy. Two types of terraces are recognized: erosional and depositional. Gravel in thin erosional terraces has Trask sorting coefficients and sedimentary structures typical of streamflood deposits, replete with bar-and-swale surface topography on young terraces. Erosional-terrace fill represents the channel fill of the stream that cuts the terrace; the thickness of the fill indicates the depth of channel scour. In contrast to erosional terraces, depositional terraces show evidence of repeated deposition and net aggradation, as indicated by their thickness (as much as 20+ m) and weakly bedded structure. Depositional terraces are common below mountain-front canyon mouths where streams drop their

  1. Late Quaternary chronostratigraphic framework of terraces and alluvium along the lower Ohio River, southwestern Indiana and western Kentucky, USA (United States)

    Counts, Ronald C.; Murari, Madhav K.; Owen, Lewis A.; Mahan, Shannon; Greenan, Michele


    The lower Ohio River valley is a terraced fluvial landscape that has been profoundly influenced by Quaternary climate change and glaciation. A modern Quaternary chronostratigraphic framework was developed for the lower Ohio River valley using optically stimulated luminescence (OSL) dating and allostratigraphic mapping to gain insights into the nature of fluvial responses to glacial–interglacial/stadial–interstadial transitions and Holocene climate change. River deposits, T0 (youngest) to T7 (oldest), were mapped along a 75 km reach of the lower Ohio River and were dated using 46 OSL and 5 radiocarbon samples. The examination of cores combined with OSL and radiocarbon dating shows that fluvial sediments older than marine oxygen isotope stage (MIS) 2 are present only in the subsurface. Aggradation during MIS 6 (Illinoian glaciation) filled the valley to within ∼7 m of the modern floodplain, and by ∼114 ka (MIS 5e/Sangamon interglacial) the Ohio River had scoured the MIS 6 sediments to ∼22 m below the modern floodplain surface. There were no fluvial sediments in the valley with ages between MIS 5e and the middle of MIS 3. The MIS 3 ages (∼39 ka) and stratigraphic position of T5 deposits suggest the Ohio River aggraded 8–14 m during MIS 4 or MIS 3. Near the end of MIS 3, the Ohio River incised the mid Last Glacial (mid-Wisconsinan) deposits ∼10 m and began aggrading again by ∼30 ka. Aggradation continued into MIS 2, with maximum MIS 2 aggradation occurring before ∼21 ka, which is coincident with the global Last Glacial Maximum (LGM). As the Ohio River adjusted to changing fluxes in sediment load and discharge following the LGM, it formed a sequence of fill-cut terraces in the MIS 2 outwash that get progressively younger with decreasing elevation, ranging in age from ∼21 ka to ∼13 ka. From ∼14 ka to ∼13 ka the Ohio River rapidly incised ∼3 m to form a new terrace, and by ∼12 ka at the onset of the Holocene, the Ohio River

  2. Records of human occupation from Pleistocene river terrace and aeolian sediments in the Arneiro depression (Lower Tejo River, central eastern Portugal) (United States)

    Cunha, Pedro P.; Almeida, Nelson A. C.; Aubry, Thierry; Martins, António A.; Murray, Andrew S.; Buylaert, Jan-Pieter; Sohbati, Reza; Raposo, Luis; Rocha, Leonor


    In the uppermost reach of the Lower Tejo River (eastern central Portugal), where the river crosses two quartzite ridges that separate the Ródão (upstream) and Arneiro (downstream) depressions, Palaeolithic artefacts have been recovered from three lower river terrace levels and a cover unit of aeolian sands. This paper presents data on the discovery of archaeological artefacts from the terrace levels and the aeolian sands that can be linked to Middle and Upper Palaeolithic industries from new field sites at Tapada do Montinho and Castelejo. The archaeological data when placed in a geomorphological, sedimentary and chronological framework, contribute new information on the understanding of human occupation in western Iberia during cold-climate episodes of the last 62 to 12 ka; and especially during the cooler and driest conditions that occurred between 32 and 12 ka, when the climate favoured aeolian sediment transport. In the Lower Tejo River, the integration of absolute age datasets with archaeological, geomorphological and sedimentary data indicate that in westernmost Iberia the first appearance of artefacts in river terrace sediments suggests that the earliest marker for human occupation dates from the lower Acheulian (Lower Palaeolithic), probably corresponding to an age of ~ 340 ka. Data also suggest, for the first time, that Acheulian lithic industries were replaced by Middle Palaeolithic ones (namely the Levallois stone knapping technique) by ~ 160 ka (~ MIS6). Middle Palaeolithic industries were later replaced by Upper Palaeolithic industries at 32 ka. The post 32 ka period, dominated by aeolian sediment transport, is related to the onset of cold-dry climate conditions which resulted in low river flow discharges, floodplain exposure and reworking by NW winds. This cold-dry period is coeval with the disappearance of Megafauna and associated Neanderthal communities, and the replacement of the Middle Palaeolithic industries by Upper Palaeolithic ones in this

  3. Autogenic incision and terrace formation resulting from abrupt late-glacial base-level fall, lower Chippewa River, Wisconsin, USA (United States)

    Faulkner, Douglas J.; Larson, Phillip H.; Jol, Harry M.; Running, Garry L.; Loope, Henry M.; Goble, Ronald J.


    A paucity of research exists regarding the millennial-scale response of inland alluvial streams to abrupt base-level fall. Studies of modern systems indicate that, over short time scales, the response is a diffusion-like process of upstream-propagating incision. In contrast, evidence from the lower Chippewa River (LCR), located in the upper Midwest of the USA, suggests that autogenic controls operating over time scales of several millennia can overwhelm diffusion, resulting in incision that is prolonged and episodic. During the Last Glacial Maximum, the LCR drained the Chippewa Lobe of the Laurentide Ice Sheet to the glacial upper Mississippi River (UMR). As a meltwater stream, it aggraded and filled its valley with glacial outwash, as did its largest tributaries, which were also meltwater streams. Its nonglacial tributaries aggraded, too, filling their valleys with locally derived sediment. During deglaciation, the UMR incised at least twice, abruptly lowering the LCR's base level - ~ 15 m at 16 ka or earlier and an additional 40 m at ca. 13.4 ka. Each of these base-level falls initiated incision of the LCR, led by upstream migrating knickpoints. The propagation of incision has, however, been a lengthy process. The optically stimulated luminescence (OSL) ages of terrace alluvium indicate that, by 13.5 ka, incision had advanced up the LCR only 15 km, and by 9 ka, only 55 km. The process has also been episodic, resulting in the formation of fill-cut terraces (inferred from GPR surveys and exposures of terrace alluvium) that are younger and more numerous in the upstream direction. Autogenic increases in sediment load and autogenic bed armoring, the result of periodic tributary-stream rejuvenation and preferential winnowing of fines by the incising river, may have periodically caused knickpoint migration and incision to slow and possibly stop, allowing lateral erosion and floodplain formation to dominate. A decline in sediment flux from stabilizing incised tributary

  4. Controls on dryland mountain landscape development along the NW Saharan desert margin: Insights from Quaternary river terrace sequences (Dadès River, south-central High Atlas, Morocco) (United States)

    Stokes, M.; Mather, A. E.; Belfoul, M.; Faik, F.; Bouzid, S.; Geach, M. R.; Cunha, P. P.; Boulton, S. J.; Thiel, C.


    This study documents river terraces from upstream reaches of the Dadès River, a major fluvial system draining the south-central High Atlas Mountains. Terraces occur as straths with bedrock bases positioned at 10 m altitudinal intervals up to 40 m (T1-T5) above the valley floor, becoming less common between 50 and 140 m. The rock strength, stratigraphy and structure of the mountain belt influences terrace distribution. Terraces are absent in river gorges of structurally thickened limestone; whilst well-developed, laterally continuous terraces (T1-T4) form along wide valleys occupying syncline structures dominated by weaker interbedded limestone-mudstone. Terrace staircases develop in confined canyons associated with weaker lithologies and influence from structural dip and stratigraphic configuration. Terraces comprise a bedrock erosion surface overlain by fluvial conglomerates, rare overbank sands and colluvium. This sequence with some OSL/IRSL age control, suggests terrace formation over a 100 ka climate cycle with valley floor aggradation during full glacials and incision during glacial-interglacial transitions. This integrates with other archives (e.g. lakes, glaciers, dunes), appearing typical of landscape development along the NW Saharan margin south of the High Atlas, and similar to patterns in the western-southern Mediterranean. The 100 ka climate cycle relationship suggests that the terrace sequence documents Late-Middle Pleistocene landscape development. Consistent altitudinal spacing of terraces and their distribution throughout the orogen suggests sustained base-level lowering linked to uplift-exhumation of the High Atlas. Low incision rates (<0.2 mm a-1) and general absence of terrace deformation suggests dominance of isostatically driven base-level lowering with relief generation being Early Pleistocene or older.

  5. Performance Evaluation of Four DEM-Based Fluvial Terrace Mapping Methods Across Variable Geomorphic Settings: Application to the Sheepscot River Watershed, Maine (United States)

    Hopkins, A. J.; Snyder, N. P.


    Fluvial terraces are utilized in geomorphic studies as recorders of land-use, climate, and tectonic history. Advances in digital topographic data, such as high-resolution digital elevation models (DEMs) derived from airborne lidar surveys, has promoted the development of several methods used to extract terraces from DEMs based on their characteristic morphology. The post-glacial landscape of the Sheepscot River watershed, Maine, where strath and fill terraces are present and record Pleistocene deglaciation, Holocene eustatic forcing, and Anthropocene land-use change, was selected to implement a comparison between terrace mapping methodologies. At four study sites within the watershed, terraces were manually mapped to facilitate the comparison between fully and semi-automated DEM-based mapping procedures, including: (1) edge detection functions in Matlab, (2) feature classification algorithms developed by Wood (1996), (3) spatial relationships between interpreted terraces and surrounding topography (Walter et al., 2007), and (4) the TerEx terrace mapping toolbox developed by Stout and Belmont (2014). Each method was evaluated based on its accuracy and ease of implementation. The four study sites have varying longitudinal slope (0.1% - 5%), channel width (lidar DEMs.

  6. 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.


    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.......004–0.055 m/ka for the last 3.6 Ma, but 0.017–0.118 m/ka for the last ~ 1.8 Ma (using as references, respectively, the base and the surface of the uppermost sedimentary unit). The facies associations that characterize the older terrace deposits (T1 and T2) consist of poorly sorted fluvial sandy...... and MIS2). Some sandy colluvium deposits on the slopes are probably related with mild-cold and wet climate conditions during the period 60 to 32 ka. The aeolian dunes are younger (cold to temperate dry conditions; MIS2 and MIS1)....

  7. Controls on dryland mountain landscape development along the NW Saharan desert margin: Insights from Quaternary river terrace sequences (Dadès River, south-central High Atlas, Morocco)

    DEFF Research Database (Denmark)

    Stokes, M.; Mather, A.E.; Belfoul, M.


    between 50 and 140 m. The rock strength, stratigraphy and structure of the mountain belt influences terrace distribution. Terraces are absent in river gorges of structurally thickened limestone; whilst well-developed, laterally continuous terraces (T1-T4) form along wide valleys occupying syncline...... sands and colluvium. This sequence with some OSL/IRSL age control, suggests terrace formation over a 100 ka climate cycle with valley floor aggradation during full glacials and incision during glacial-interglacial transitions. This integrates with other archives (e.g. lakes, glaciers, dunes), appearing...... typical of landscape development along the NW Saharan margin south of the High Atlas, and similar to patterns in the western-southern Mediterranean. The 100 ka climate cycle relationship suggests that the terrace sequence documents Late-Middle Pleistocene landscape development. Consistent altitudinal...

  8. Thalassostatic terraces and Pleistocene chronology

    NARCIS (Netherlands)

    Brouwer, A.


    Rejuvenation and aggradation are among the usual adaptations of a river under changing conditions. Terraces may result from rejuvenation, and a repeated alternation of rejuvenation and aggradation may lead, but does not necessarily so, to the formation of a sequence of terraces bordering a valley. M

  9. Timing and development of Late Quaternary fluvial terraces of the lower course of Kızılırmak River (Northern Turkey) (United States)

    Berndt, Christopher; Yıldırım, Cengiz; Çiner, Attila; Ertunç, Gülgün; Akif Sarıkaya, M.; Özcan, Orkan; Güneç Kıyak, Nafiye; Öztürk, Tuǧba


    The Kızılırmak River (1355 km) is the longest river of Anatolia. It traverses the Central Pontides and forms deep bedrock gorges, fluvial and deltaic terraces along its lower stream and a large delta into the Black Sea. The Central Pontides is an actively deforming and uplifting mountain range located at the northern margin of the Central Anatolian Plateau (CAP). The presence of strath terraces and uplifted paleo-delta levels along the lower course of the river indicates a response of Kızılırmak to active uplift of the Central Pontides and sea-level fluctuations of the Black Sea. To understand the Quaternary tectonic, climatic and sea level impacts on the lower stream and delta of the Kızılırmak River, we carried out geologic and geomorphic mapping of several fluvial and deltaic terraces in order to date 5 levels by optically stimulated luminescence dating (OSL) method. Our results indicate accelerated regional uplift since Middle Pleistocene in the eastern part of the Central Pontides with uplift rates varying between about 0.07 and 0.3 m/ka. The delta terraces at 103 and 123 m above mean river level on the western side of Kızılırmak River uplifted presumably faster than the terraces at 58 and 87 m above mean river level on the eastern side by 0.2-0.3 m/ka. Since MIS 9 the western and eastern delta platforms uplift coherently with 0.2 m/ka or less. The southern part of the delta is delimited by Alaçam Segment of the Erikli Fault. The area south of the Alaçam segment of the Erikli Fault is uplifting faster than the region to the north of it (0.07 m/ka) since Middle Pleistocene. This indicates a tectonic interaction between the positive flower structure of the North Anatolian Fault Zone and an active rifting of the Sinop Graben over the Erikli Fault system.

  10. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the North Canadian River from Oklahoma City to Eufaula Lake in east-central Oklahoma (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital aquifer boundaries for the alluvial and terrace deposits along the North Canadian River from Oklahoma City to Eufaula Lake in...

  11. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the Beaver-North Canadian River from the panhandle to Canton Lake in northwestern Oklahoma (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital polygons of a constant recharge value for the alluvial and terrace deposits along the Beaver-North Canadian River from the...

  12. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the North Canadian River from Oklahoma City to Eufaula Lake in east-central Oklahoma (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital water-level elevation contours for the alluvial and terrace deposits along the North Canadian River from Oklahoma City to Eufaula...

  13. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the Beaver-North Canadian River from the panhandle to Canton Lake in northwestern Oklahoma (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital hydraulic conductivity values for the alluvial and terrace deposits along the Beaver-North Canadian River from the panhandle to...

  14. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the North Canadian River from Oklahoma City to Eufaula Lake in east-central Oklahoma (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital polygons of a constant recharge value for the alluvial and terrace deposits along the North Canadian River from Oklahoma City to...

  15. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the North Canadian River from Oklahoma City to Eufaula Lake in east-central Oklahoma (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital polygons of a constant hydraulic conductivity value for the alluvial and terrace deposits along the North Canadian River from...

  16. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the Beaver-North Canadian River from the panhandle to Canton Lake in northwestern Oklahoma (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital aquifer boundaries for the alluvial and terrace deposits along the Beaver-North Canadian River from the panhandle to Canton Lake in...

  17. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the Beaver-North Canadian River from the panhandle to Canton Lake in northwestern Oklahoma (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital water-level elevation contours for the Quaternary alluvial and terrace deposits along the Beaver-North Canadian River from the...

  18. Geomorphic evidence for Quaternary tectonics on the southern flank of the Yellowstone hotspots from terraces and stream profiles along the Hoback and Snake River (United States)

    Bufe, Aaron; Pederson, Joel; Tuzlak, Daphnee


    The greater Yellowstone region offers a type example of Earth surface response to a mantle anomaly. Motion of the North American plate across the Yellowstone plume over the past 17 Ma is predicted to have produced a wave of transient uplift and extension of the upper crust. In the wake of the plume, the Snake River Plain (SRP) has been subsiding 4-8 km due to a combination of crustal loading by basaltic magmatism and cooling. Studying patterns and rates of Quaternary incision of rivers flowing off the Yellowstone plateau can test models about the distribution and timing of active uplift, subsidence, and faulting, improving our understanding of the geodynamics and the hazards in the region. We present results from surveying and optically stimulated luminescence (OSL) dating of river terraces along the Hoback and upper Snake rivers (western Wyoming and southeastern Idaho), which provide a study transect from the modern Yellowstone hotspot center, across zones of changing fault activity, into the subsiding SRP. Downstream of Palisades Reservoir, dated fill terraces reveal that the Snake River has seen no apparent net incision since 50-60 ky. Moreover, a paleo-channel bed preserved by a 2 My-old basalt flow and exposed <10 m above the modern river suggests that net incision rates averaged over 2 My were <5 m/My. In contrast, upstream of Alpine, we find that three levels of 10-90 ky-old strath terraces record recent incision at rates of 0.1-0.3 mm/y along the deeply incised Alpine Canyon and the Hoback River. Here, the pattern of incision rates appear to be controlled by local baselevel fall along normal faults and we hypothesize that rates of subsidence of the SRP in the Quaternary have been relatively slow (< 0.1 mm/y).

  19. Terrace Town (United States)

    Sabin, Heather


    The "Terrace Town" program brings architecture and city planning curriculum to elementary schools in Madison, Wisconsin, and surrounding areas. Over eight weeks, classrooms discuss what makes a community livable, sustainable, and kid-friendly. Throughout the process, students gain a better understanding of their own city environments and…

  20. 黄河三门峡至扣马段的阶地序列及成因%Sequences and genesis of the Yellow River terraces from Sanmen Gorge to Kouma

    Institute of Scientific and Technical Information of China (English)

    苏怀; 王均平; 潘保田; 明庆忠; 李琼


    Based on field landscape investigations, thermoluminescence (TL), magnetostrati- graphy and Ioess-paleosol sequence, we found that there are at least four Yellow River ter- races, whose ages are 0.86 Ma, 0.62 Ma, 0.13 Ma and 0.05 Ma, in Yuxi Fault-Uplift (from Sanmen Gorge to Mengjin) and at least three Yellow River terraces, whose ages are 1.24 Ma, 0.25 Ma and 0.05 Ma, in Huabei Fault Depression (from Mengjin to Kouma). All the terraces have a similar structure that several meters of paleosols directly develop on the top of fluvial silt. It shows that the Yellow River incised and consequently abandoned floodplain converted to terrace during the intergtaciat period. Therefore, there may be a link between the formation of terraces and glacial-interglacial climatic cycles. However, the differences in the Yellow River terrace sequences and ages between Yuxi Fault-Uplift and Huabei Fault Depression indicate that the surface uplift should play an important role in the formation of these terraces.

  1. Roles of saltcedar (Tamarix spp.) and capillary rise in salinizing a non-flooding terrace on a flow-regulated desert river (United States)

    Glenn, Edward P.; Morino, Kiyomi; Nagler, Pamela L.; Murray, R. Scott; Pearlstein, Susanna; Hultine, Kevin R.


    Tamarix spp. (saltcedar) secretes salts and has been considered to be a major factor contributing to the salinization of river terraces in western US riparian zones. However, salinization can also occur from the capillary rise of salts from the aquifer into the vadose zone. We investigated the roles of saltcedar and physical factors in salinizing the soil profile of a non-flooding terrace at sites on the Cibola National Wildlife Refuge on the Lower Colorado River, USA. We placed salt traps under and between saltcedar shrubs and estimated the annual deposition rate of salts from saltcedar. These were then compared to the quantities and distribution on of salts in the soil profile. Dense stands of saltcedar deposited 0.159 kg m-2 yr-1 of salts to the soil surface. If this rate was constant since seasonal flooding ceased in 1938 and all of the salts were retained in the soil profile, they could account for 11.4 kg m-2 of salt, about 30% of total salts in the profile today. Eliminating saltcedar would not necessarily reduce salts, because vegetation reduces the upward migration of salts in bulk flow from the aquifer. The densest saltcedar stand had the lowest salt levels in the vadose zone in this study.

  2. Staking Terraces Online: A Terrace Layout Program (United States)

    Terrace construction in Missouri exceeded 3 million feet at a cost of over $8 million in 2008. Up to 50 % of the total construction and design time is spent on the terrace layout itself. A web-based computer program, MOTERR, has been developed to design terrace layouts. The program utilizes digital ...

  3. Numerical model predictions of autogenic fluvial terraces and comparison to climate change expectations (United States)

    Limaye, Ajay B. S.; Lamb, Michael P.


    Terraces eroded into sediment (alluvial) and bedrock (strath) preserve an important history of river activity. River terraces are thought to form when a river switches from a period of slow vertical incision and valley widening to fast vertical incision and terrace abandonment. Consequently, terraces are often interpreted to reflect changing external drivers including tectonics, sea level, and climate. In contrast, the intrinsic unsteadiness of lateral migration in rivers may generate terraces even under constant rates of vertical incision without external forcing. To explore this mechanism, we simulate landscape evolution by a vertically incising, meandering river and isolate the age and geometry of autogenic river terraces. Modeled autogenic terraces form for a wide range of lateral and vertical incision rates and are often paired and longitudinally extensive for intermediate ratios of vertical-to-lateral erosion rate. Autogenic terraces have a characteristic reoccurrence time that scales with the time for relief generation. There is a preservation bias against older terraces due to reworking of previously visited parts of the valley. Evolving, spatial differences in bank strength between bedrock and sediment reduce terrace formation frequency and length, favor pairing, and can explain sublinear terrace margins at valley boundaries. Age differences and geometries for modeled autogenic terraces are consistent, in cases, with natural terraces and overlap with metrics commonly attributed to terrace formation due to climate change. We suggest a new phase space of terrace properties that may allow differentiation of autogenic terraces from terraces formed by external drivers.

  4. The age of the 20 meter Solo River terrace, Java, Indonesia and the survival of Homo erectus in Asia. (United States)

    Indriati, Etty; Swisher, Carl C; Lepre, Christopher; Quinn, Rhonda L; Suriyanto, Rusyad A; Hascaryo, Agus T; Grün, Rainer; Feibel, Craig S; Pobiner, Briana L; Aubert, Maxime; Lees, Wendy; Antón, Susan C


    Homo erectus was the first human lineage to disperse widely throughout the Old World, the only hominin in Asia through much of the Pleistocene, and was likely ancestral to H. sapiens. The demise of this taxon remains obscure because of uncertainties regarding the geological age of its youngest populations. In 1996, some of us co-published electron spin resonance (ESR) and uranium series (U-series) results indicating an age as young as 35-50 ka for the late H. erectus sites of Ngandong and Sambungmacan and the faunal site of Jigar (Indonesia). If correct, these ages favor an African origin for recent humans who would overlap with H. erectus in time and space. Here, we report (40)Ar/(39)Ar incremental heating analyses and new ESR/U-series age estimates from the "20 m terrace" at Ngandong and Jigar. Both data sets are internally consistent and provide no evidence for reworking, yet they are inconsistent with one another. The (40)Ar/(39)Ar analyses give an average age of 546±12 ka (sd±5 se) for both sites, the first reliable radiometric indications of a middle Pleistocene component for the terrace. Given the technical accuracy and consistency of the analyses, the argon ages represent either the actual age or the maximum age for the terrace and are significantly older than previous estimates. Most of the ESR/U-series results are older as well, but the oldest that meets all modeling criteria is 143 ka+20/-17. Most samples indicated leaching of uranium and likely represent either the actual or the minimum age of the terrace. Given known sources of error, the U-series results could be consistent with a middle Pleistocene age. However, the ESR and (40)Ar/(39)Ar ages preclude one another. Regardless, the age of the sites and hominins is at least bracketed between these estimates and is older than currently accepted.

  5. The Age of the 20 Meter Solo River Terrace, Java, Indonesia and the Survival of Homo erectus in Asia (United States)

    Indriati, Etty; Swisher, Carl C.; Lepre, Christopher; Quinn, Rhonda L.; Suriyanto, Rusyad A.; Hascaryo, Agus T.; Grün, Rainer; Feibel, Craig S.; Pobiner, Briana L.; Aubert, Maxime; Lees, Wendy; Antón, Susan C.


    Homo erectus was the first human lineage to disperse widely throughout the Old World, the only hominin in Asia through much of the Pleistocene, and was likely ancestral to H. sapiens. The demise of this taxon remains obscure because of uncertainties regarding the geological age of its youngest populations. In 1996, some of us co-published electron spin resonance (ESR) and uranium series (U-series) results indicating an age as young as 35–50 ka for the late H. erectus sites of Ngandong and Sambungmacan and the faunal site of Jigar (Indonesia). If correct, these ages favor an African origin for recent humans who would overlap with H. erectus in time and space. Here, we report 40Ar/39Ar incremental heating analyses and new ESR/U-series age estimates from the “20 m terrace" at Ngandong and Jigar. Both data sets are internally consistent and provide no evidence for reworking, yet they are inconsistent with one another. The 40Ar/39Ar analyses give an average age of 546±12 ka (sd±5 se) for both sites, the first reliable radiometric indications of a middle Pleistocene component for the terrace. Given the technical accuracy and consistency of the analyses, the argon ages represent either the actual age or the maximum age for the terrace and are significantly older than previous estimates. Most of the ESR/U-series results are older as well, but the oldest that meets all modeling criteria is 143 ka+20/−17. Most samples indicated leaching of uranium and likely represent either the actual or the minimum age of the terrace. Given known sources of error, the U-series results could be consistent with a middle Pleistocene age. However, the ESR and 40Ar/39Ar ages preclude one another. Regardless, the age of the sites and hominins is at least bracketed between these estimates and is older than currently accepted. PMID:21738710

  6. Archaic Industries of Roussillon (South of France: Geochronological Correlation with the Terraces of the Têt, Tech and Agly Rivers

    Directory of Open Access Journals (Sweden)



    Full Text Available This article studies the lithic industry of the Early Palaeolithic from the terraces of the Roussillon, in the S of France. The geomorphological revision of the flood levels allows these industries to be related to the geochronology of the terraces which were formed in between the late Early Pleistocene and the Middle Pleistocene, and thus allows a regional chrono-cultural framework to be established. By analyzing the technology of the lithic industry derived from the concept of chaîne opératoire and studying the patinas, the technical Modes and the technological aspects of the processes related to configuration and knapping sequences are differentiated. In the fluvial sequence, Mode 1 is documented in the terrace of Mas Ferréol and Mode 2 is identified in the Plane d’en Bourgat and Butte du Four-Llabanère, thus showing a technological continuity in the form of choppers and chopping-tools and poorly organized chains of exploitation (polyhedral. This technological substratum is common to the coeval sites from the NE of the Iberian Peninsula and the S of France, although with a margin of variability between the industries from the different regions.

  7. San Isidro (Madrid: 1862-2002. New Palaeolithic finds from the +30 terrace of the Manzanares river

    Directory of Open Access Journals (Sweden)

    Gómez Hernanz, Juan


    Full Text Available The archaeo-palaeontological survey carried out on a site located at Cerro de San Isidro (Madrid, because of a project of construction in that place, has led to the documentation of a small part of the ancient terrace which has almost totally disappeared as a result of quarrying. The study of the stratigraphic sequence, the recovery of several pieces of lithic industry, as well as pollen analyses, have allowed us to contribute new data to the already known “Terrace of San Isidro” that was known from the middle of the nineteenth century.

    El seguimiento arqueo-paleontológico realizado en un solar sito en el Cerro de San Isidro, con motivo de un proyecto constructivo en dicho lugar, ha llevado a la documentación de un pequeño resto de la antigua terraza a +30 m, probablemente muy mal conservada por su explotación como arenero en el pasado y por las actuaciones urbanísticas en la zona. El estudio de la secuencia estratigráfica, la recuperación de varias piezas de industria lítica, así como la realización de análisis polínicos, ha permitido aportar nuevos datos a los ya conocidos de la denominada “Terraza de San Isidro” que se remontan a mediados del siglo XIX.

  8. A multiple dating approach (luminescence and electron spin resonance) to assess rates of crustal deformation using Quaternary fluvial terraces of the lower Moulouya River (NE Morocco) (United States)

    Bartz, Melanie; Rixhon, Gilles; Duval, Mathieu; King, Georgina; Brückner, Helmut


    The Moulouya River, the largest catchment in Morocco, drains an area characterized by active crustal deformation during the Late Cenozoic due to the convergence between the African and Eurasian plates. Our study focuses on the lowermost reach of the river in NE Morocco, where a thrust zone associated with N-S compressive shortening in this region was identified (Barcos et al., 2014; Rixhon et al., 2017). New geomorphological results demonstrate contrasting fluvial environments on each side of the thrust: long-lasting fluvial aggradation, materialized by >37 m-thick stacked fill terraces, and the development of a well-preserved terrace staircase, with three Pleistocene terrace levels, occurred in the footwall and the hanging wall, respectively (Rixhon et al., 2017). Here, we present a preliminary geochronological background for these contrasting terrace systems based on a multiple dating approach. Samples for (i) luminescence (pIRIR225 and pIRIR290 dating of coarse-grained K-feldspars) and (ii) electron spin resonance (ESR dating of coarse-grained quartz) from four different profiles were collected. (i) Due to the application of the athermal detrapping model by Huntley (2006) (modified after Kars et al., 2008), it appears that the feldspar signals are in sample specific field saturation. Our results yielded minimum ages of 0.9 Ma and 0.7 Ma for the footwall and hanging wall, respectively. (ii) Using the multiple centre approach with ESR dating (Duval et al., 2015), we measured both the aluminium (Al) and the titanium (Ti) centres in order to evaluate whether they would provide consistent results. Results indicate that De values of the Al centre are either slightly higher compared to those of the Ti centre or they agree within a 1σ-error range, which may simply be due to the slower bleaching kinetics of the Al centre. Thus, the ESR ages were inferred from the Ti centre. Ages between 1.35±0.10 and 1.17±0.10 Ma in the footwall show sediment aggradation between MIS

  9. Study of extrabasinal-sourced rock clasts in Mesozoic and Cenozoic conglomerates and stream terrace gravels from the Colorado River Basin upstream from the Grand Canyon (United States)

    Stoffer, P. W.; Dearaujo, J.; Li, A.; Adam, H.; White, L.


    Far-travelled durable, extrabasinal pebbles occur in Mesozoic and Tertiary conglomerate-bearing rock formations and in unconsolidated stream terrace gravels and mesa-capping gravel deposits of Late Tertiary and Quaternary age throughout the Colorado Plateau. Pebble collections were made from each of the major modern tributaries of the Colorado River for possible correlation of remnant gravel deposits remaining from the ancestral regional drainage system that existed prior to the formation of the Grand Canyon. Pebble collecting and sorting techniques were used to make representative collections with both representative and eye-catching lithologies that can be most useful for correlation. Pebbles found in the conglomerate and younger gravel deposits were evaluated to determine general sediment source areas based on unique lithologies, pebble-shape characteristics, and fossils. Chert pebbles derived from source areas in the Great Basin region during the Mesozoic are perhaps the most common, and many of these display evidence of tectonic fracturing during deep burial sometime during their geologic journey. Unique chert pebble lithologies correlate to specific rock units including chert-bearing horizons within the Triassic Shinarump Formation, the Jurassic Morrison and Navajo Formations, and the Cretaceous Mancos Shale. Quartzite, metaconglomerate, and granitic rocks derived from Precambrian rocks of the Rocky Mountain region are also common. Reworked rounded and flattened quartzite cobbles probably derived from shingled beaches along the western shoreline of the Late Cretaceous Western Interior Seaway are also common along the Green River drainage. Xenolith-bearing volcanic rocks, fossil wood, and shell fossils preserved in concretion matrix can be linked to other unique source areas and stratigraphic units across the region. By correlating the pebbles with their sources we gain insight into the erosional history of the Colorado Plateau and the evolution of the

  10. Can we follow the neotectonic activity of the Hluboká-fault by reconstructing the evolution of the Vltava river course? - Mapping of fluvial terraces around the Budejovice-basin using historic maps (United States)

    Homolova, Dana; Lomax, Johanna; Prachar, Ivan; Spacek, Petr; Zamolyi, Andras; Decker, Kurt


    The Budějovice Basin in the Bohemian Massif (Czech Republic) is a fault-bounded sedimentary basin with a multiple subsidence history overlying Variscan crystalline basement. Permian, Cretaceous and Miocene sediments record repeated reactivations of faults at or close to the basin margin, which may have continued into the Quaternary. The latter is indicated by geomorphological features such as linear topographic scarps, which characterize part of the faults within and at the border of the Budějovice Basin. In a current study we assess possible Quaternary displacements along the faults delimiting the basin using geomorphological data, analyses of river planform patterns and correlations of Quaternary terraces of the Vltava River, which crosses the basin and its boundary faults. The regionally most important tectonic feature - the Hluboká fault -forms the northeastern margin of the Budějovice basin. The fault crosses the course of the river Vltava, a fact that guided our research to take a more precise look at the character and distribution of fluvial sediments in this area. Our main focus is on dating of terrace bodies around the Hluboká fault. According to the scheme used in most European regions, influences by the Pleistocene glacial cycles, the Vltava river terraces were assigned by most scientists to the 4(5) main alpine glacial periods. This dating is not straightforward as terraces are not connected to moraine bodies like in the Alps. The terraces were basically correlated by their altitude above the river and by their lithology (clastic content and grain size composition), but mostly without any numerical age determination. Our studies include several field and laboratory methods, supported by computer analyses of various types of spatial data. Data sources include: (i) modern topographic maps, (ii) geological maps, (iii) georeferenced historic map sheets of the Austrian Second Military Survey (provided by the Geoinformatics Laboratory of the University J

  11. Alluvial terrace preservation in the Wet Tropics, northeast Queensland, Australia (United States)

    Hughes, Kate; Croke, Jacky; Bartley, Rebecca; Thompson, Chris; Sharma, Ashneel


    Alluvial terraces provide a record of aggradation and incision and are studied to understand river response to changes in climate, tectonic activity, sea level, and factors internal to the river system. Terraces form in all climatic regions and in a range of geomorphic settings; however, relatively few studies have been undertaken in tectonically stable settings in the tropics. The preservation of alluvial terraces in a valley is driven by lateral channel adjustments, vertical incision, aggradation, and channel stability, processes that can be further understood through examining catchment force-resistance frameworks. This study maps and classifies terraces using soil type, surface elevation, sedimentology, and optically stimulated luminescence dating across five tropical catchments in northeast Queensland, Australia. This allowed for the identification of two terraces across the study catchments (T1, T2). The T1 terrace was abandoned ~ 13.9 ka with its subsequent removal occurring until ~ 7.4 ka. Abandonment of the T2 terrace occurred ~ 4.9 ka with removal occurring until ~ 1.2 ka. Differences in the spatial preservation of these terraces were described using an index of terrace preservation (TPI). Assessments of terrace remnant configuration highlighted three main types of terraces: paired, unpaired, and disconnected, indicating the importance of different processes driving preservation. Regional-scale variability in TPI was not strongly correlated with catchment-scale surrogate variables for drivers of terrace erosion and resistance. However, catchment-specific relationships between TPI and erosion-resistance variables were evident and are used here to explain the dominant processes driving preservation in these tropical settings. This study provides an important insight into terrace preservation in the tectonically stable, humid tropics and provides a framework for future research linking the timing of fluvial response to palaeoclimate change.


    Institute of Scientific and Technical Information of China (English)

    杨晓平; 李安; 黄伟亮; 张玲


    Using the aerial remote sensing photos and Google earth satellite images,we find seven terraces at the both sides along the Kuytun River in Dushanzi active anticline area, northern piedmont of Tians-han. Based on the field investigation, we find that all these terraces are pedestal terraces. The rock of pedestal is Pliocene mud rock, and on the top of each terrace pedestal are the stratums of sandy gravel or sandy clay with 2. 5 ~ 15m in thickness. We collected samples from deposits of all terraces for OSL (optically stimulated luminescence) geological dating using the SMAR( single-multiple-aliquot-regeneration) method on fine grains. We also performed dating using the C method to the samples from the deposit of terrace T, of the Kuytun River. The results show that the ages of all these deposits are the later phase of the Late Pleistocene. The accumulation time of the upper stratum for T, , T2, T3 , T5 , T6and T7 terraces is about 1. 7ka, 14. 98ka,20. 7 ~ 27. 3ka,29. 3 ~ 39. 2ka,47 ~ 56ka and 103 ~ 118ka,respectively. Combining with late Quaternary climate change,we believe that the formation age forT1 ~T7 terraces of Kuytun River are 1. 7ka, 14ka,20ka,25ka, 30ka,50ka and lOOkaBP. Paleo-earthquake data reveal that eight paleoearthquake events occurred on the Dushanzi-Anjihai reverse fault since about 25ka BP, respectively at 2ka, 3. 4ka, 4. 3ka, 5. 8ka, 7. 5ka, 12. 8ka, 18ka and 24ka BP. Comparing the ages of paleoearthquakes and terraces,we find that the ages of the latest,the sixth, the seventh and the eighth paleoearthquake are roughly corresponding to the formation times of T1 , T2 ,T3and T4 terraces,respectively. The other four paleoearthquake events occurred during the period after the formation of T2and before the formation of T,. In this time,no terraces developed along the Kuytun River, but the Kuytun River incised rapidly for 40m. We believe that the paleoearthquake e-vents resulted in the fast uplift of Dushanzi active anticline on the hanging wall of

  13. Predicting reach-specific properties of fluvial terraces to guide future fieldwork. A case study for the Late Quaternary River Allier (France) with the FLUVER2 model

    NARCIS (Netherlands)

    Veldkamp, Tom; Schoorl, Jeroen M.; Viveen, Willem


    Numerical models have not yet systematically been used to predict properties of fluvial terrace records in order to guide fieldwork and sampling. This paper explores the potential of the longitudinal profile model FLUVER2 to predict testable field properties of the relatively well-studied, Late Quat

  14. Large depressions, thickened terraces, and gravitational deformation in the Ebro River valley (Zaragoza area, NE Spain): Evidence of glauberite and halite interstratal karstification (United States)

    Guerrero, Jesús; Gutiérrez, Francisco; Galve, Jorge P.


    In the studied reach of the Ebro Valley, the terrace and pediment sediments deposited over glauberite- and halite-bearing evaporites show local thickenings (> 50 m) recording dissolution-induced synsedimentary subsidence. Recent data on the lithostratigraphy of the evaporite sequence allow relating the alluvium thickenings with either halite or glauberite dissolution. The alluvium-filled dissolution basin underlying the youngest terraces (T8-T11) is ascribed to halite karstification; the top of a halite unit approximately 75 m thick is situated 40-15 m below the valley bottom. The thickenings of terrace (T1-T7) and pediment sediments are attributed to interstratal glauberite karstification: (1) Coincidence between the elevation range of the terraces and that of the glauberite-rich unit. Glauberite beds reach 30 and 100 m in single-bed and cumulative thickness, respectively. (2) The exposed bedrock underlying thickened alluvium shows abundant subsidence features indicative of interstratal karstification. The most common structure corresponds to hectometer-scale sag basins with superimposed collapses in the central sector of each basin. The subsided bedrock is frequently transformed into dissolution-collapse breccias showing a complete textural gradation, from crackle packbreccias to chaotic floatbreccias and karstic residues. (3) Paleokarst exposures show evidence of karstification confined to specific beds made up of secondary gypsum after precursory glauberite, partly dissolved and partly replaced. Despite the magnitude of the subsidence recorded by the thickened alluvium and unlike nearby tributaries, the terraces show a continuous and parallel arrangement indicating that the fluvial system was able to counterbalance subsidence by aggradation. A number of kilometer-size flat-bottom depressions have been developed in the valley margin, typically next to and inset into thickened terrace and pediment deposits. The subsidence structures exposed in artificial

  15. The dynamics of travertine terrace formation

    CERN Document Server

    Hammer, O; Jamtveit, B; Dysthe, Dag K.; Hammer, Oyvind; Jamtveit, Bjorn


    Travertine (limestone) terraces are common in caves, springs and rivers worldwide, and represent one of the most striking examples of geological pattern formation on the Earth's surface. The terraces form over a wide range of scales, from millimeters to tens of meters. Their origin has been poorly understood, but most likely involves a coupling between the precipitation rate and hydrodynamics. Microbial activity may also play a role. Here we present a minimal model based on shallow water flow and an empirical positive correlation between the flow velocity and precipitation rate. The resulting selforganizing pattern formation process displays rich and unusual dynamics, consistent with field observations. Terraces coarsen with time, fold into lobes and migrate downstream with differential rates, resulting in striking patterns. This model, in which topography grows rather than erodes in response to rapid flow, produces patterns that are completely different from those generated by flow driven erosion.


    Institute of Scientific and Technical Information of China (English)

    吕延武; 顾兆炎; 许冰; A.Aldahan; G.Possnert


    宇宙成因核素可用于河流阶地测年,然而保存于阶地面上的漂砾暴露年龄是否能代表其形成年代还缺乏深入研究.应用宇宙成因核素10Be对怒江丙中洛河段第三级阶地上的花岗岩漂砾进行测年研究,结果显示继承性组分可以忽略,而风化侵蚀将对其暴露年龄产生较大影响.基于采集自第三级阶地保存较好的基岩中石英脉样品,应用有效暴露年龄、暴露时间与风化速率间的关系图解出花岗岩漂砾的风化速率为0.3cm/ka,并据此得到第三级阶地的形成年代大约为 150~203 ka.%Fluvial terraces are common in the Nujiang River valley,while the third level is widest and mostly distributed. There are five level terraces at Bingzhongluo(28°01'N,98°37'E) ,where located southeastern margin of the Tibetan Plateau, Yunnan, China. The third and the forth level terraces are covered with reddish-brown soil, indicating a long history of the terraces. Many granite boulders are spread out on the surface of the first, second and third level terraces, whose exposure ages could represent the terrace formation time. Three granite boulders were taken as samples at the posterior margin of the third terrace of the Nujiang River at Bingzhongluo(Fig. la and lc). The diameters of all boulders are large (>2m)and partly buried in soil layers. Sample NJ2-1 was collected from one granite boulder(about 2. 3m)on floodplain, which is used to estimate the inheritance. Sample BZL43 was chiseled about 1. 5cm from the surface of a quartz vein,which insets a sandy slate of the third terrace at downstream about 2km. The quartz purification, 10Be extraction,and BeO preparation,were done in the Cosmogenic Nuclide Laboratory at the Institute of Geology and Geophysics, Chinese Academy of Sciences. The 10e/9Be ratio was measured by AMS facility at the Tandem Laboratory of Uppsala University in Sweden. The "Be concentrations (Table 1) show that the 10Be concentration of sample BZL43 is


    Institute of Scientific and Technical Information of China (English)

    雷生学; 陈杰; 刘进峰; 尹金辉; 侯康明; 王昌盛


    The fluvial terrace has plenty of paleoclimate and paleoenviromental information which play an important role in paleoclimate and paleoenviromental researches. In this paper,we drilled a 42.85mlong core(N06S2) in 2007,which was located in the south bank of Yangtze River at Shifuqiao in Qixia district of Nanjing City.Firstly, fine quartz grains (4 ~ 11 μm ) were extracted from bulk samples in dark room, and the quartz purity tests were conducted. The results show that purity can satisfy the experiment. All measurements were performed on an automated Daybreak 2200 TL/OSL system with blue (470 ±5 nm)light stimulation and U-340 luminescence detection filters. Thick source alpha counting(TSAC)was used to measure the uranium and thorium concentrations. The potassium content was determined using flame spectrophotometer.Secondly, the preheat plateau test and dose recovery test were performed on one sample using the SAR protocol. The results indicate that the fast component dominates the OSL signals. In preheat plateau test,identical De in the thermal treat from 160 ~ 260℃ was observed ,thus we use the preheat temperature of 220℃ for 10 seconds. The recuperation ratios of zero point are below 2% and the recycling ratios lie between 0.9 and 1.1. In dose recovery test, OSL signal sensitivity changes are well corrected. Tests of luminescence characteristics confirm the suitability of the material for OSL dating.At last, samples from this drilling core were systematically dated by optically stimulated luminescenee(OSL) dating method, and samples which contain organic matters were dated by AMS 14C. The results show that the De values from the two methods accord with each other very well.However,OSL dating results show that there is a hiatus in this core, and the hiatus,which ranges from 1.9ka to 7.9ka, may be the result of change of Yangtze River's channel or the erosion of the river. The ages of the fluvial deposition mainly range from 0. 26ka to 1.9ka and 7.9ka to

  18. The cafeteria terrace

    CERN Document Server


    The large terrace area outside Restaurant 1 at CERN is a hive of activity in the summer. Visitors and staff members meet here for breaks from work. Often the air is filled with discussion in many different accents and languages on topics from theoretical physics to the weekend's activities.

  19. The twenty-first century Colorado River hot drought and implications for the future (United States)

    Udall, Bradley; Overpeck, Jonathan


    Between 2000 and 2014, annual Colorado River flows averaged 19% below the 1906-1999 average, the worst 15-year drought on record. At least one-sixth to one-half (average at one-third) of this loss is due to unprecedented temperatures (0.9°C above the 1906-1999 average), confirming model-based analysis that continued warming will likely further reduce flows. Whereas it is virtually certain that warming will continue with additional emissions of greenhouse gases to the atmosphere, there has been no observed trend toward greater precipitation in the Colorado Basin, nor are climate models in agreement that there should be a trend. Moreover, there is a significant risk of decadal and multidecadal drought in the coming century, indicating that any increase in mean precipitation will likely be offset during periods of prolonged drought. Recently published estimates of Colorado River flow sensitivity to temperature combined with a large number of recent climate model-based temperature projections indicate that continued business-as-usual warming will drive temperature-induced declines in river flow, conservatively -20% by midcentury and -35% by end-century, with support for losses exceeding -30% at midcentury and -55% at end-century. Precipitation increases may moderate these declines somewhat, but to date no such increases are evident and there is no model agreement on future precipitation changes. These results, combined with the increasing likelihood of prolonged drought in the river basin, suggest that future climate change impacts on the Colorado River flows will be much more serious than currently assumed, especially if substantial reductions in greenhouse gas emissions do not occur.Plain Language SummaryBetween 2000 and 2014, annual Colorado River flows averaged 19% below the 1906-1999 average, the worst 15-year drought on record. Approximately one-third of the flow loss is due to high temperatures now common in the basin, a result of human caused climate change

  20. Rising river flows throughout the twenty-first century in two Himalayan glacierized watersheds (United States)

    Immerzeel, W. W.; Pellicciotti, F.; Bierkens, M. F. P.


    Greater Himalayan glaciers are retreating and losing mass at rates comparable to glaciers in other regions of the world. Assessments of future changes and their associated hydrological impacts are scarce, oversimplify glacier dynamics or include a limited number of climate models. Here, we use results from the latest ensemble of climate models in combination with a high-resolution glacio-hydrological model to assess the hydrological impact of climate change on two climatically contrasting watersheds in the Greater Himalaya, the Baltoro and Langtang watersheds that drain into the Indus and Ganges rivers, respectively. We show that the largest uncertainty in future runoff is a result of variations in projected precipitation between climate models. In both watersheds, strong, but highly variable, increases in future runoff are projected and, despite the different characteristics of the watersheds, their responses are surprisingly similar. In both cases, glaciers will recede but net glacier melt runoff is on a rising limb at least until 2050. In combination with a positive change in precipitation, water availability during this century is not likely to decline. We conclude that river basins that depend on monsoon rains and glacier melt will continue to sustain the increasing water demands expected in these areas.

  1. Lithologic controls on valley width and strath terrace formation (United States)

    Schanz, Sarah A.; Montgomery, David R.


    Valley width and the degree of bedrock river terrace development vary with lithology in the Willapa and Nehalem river basins, Pacific Northwest, USA. Here, we present field-based evidence for the mechanisms by which lithology controls floodplain width and bedrock terrace formation in erosion-resistant and easily friable lithologies. We mapped valley surfaces in both basins, dated straths using radiocarbon, compared valley width versus drainage area for basalt and sedimentary bedrock valleys, and constructed slope-area plots. In the friable sedimentary bedrock, valleys are 2 to 3 times wider, host flights of strath terraces, and have concavity values near 1; whereas the erosion-resistant basalt bedrock forms narrow valleys with poorly developed, localized, or no bedrock terraces and a channel steepness index half that of the friable bedrock and an average channel concavity of about 0.5. The oldest dated strath terrace on the Willapa River, T2, was active for nearly 10,000 years, from 11,265 to 2862 calibrated years before present (cal YBP), whereas the youngest terrace, T1, is Anthropocene in age and recently abandoned. Incision rates derived from terrace ages average 0.32 mm y- 1 for T2 and 11.47 mm y- 1 for T1. Our results indicate bedrock weathering properties influence valley width through the creation of a dense fracture network in the friable bedrock that results in high rates of lateral erosion of exposed bedrock banks. Conversely, the erosion-resistant bedrock has concavity values more typical of detachment-limited streams, exhibits a sparse fracture network, and displays evidence for infrequent episodic block erosion and plucking. Lithology thereby plays a direct role on the rates of lateral erosion, influencing valley width and the potential for strath terrace planation and preservation.

  2. Palaeoenvironment and dating of the Early Acheulean localities from the Somme River basin (Northern France): New discoveries from the High Terrace at Abbeville-Carrière Carpentier (United States)

    Antoine, Pierre; Moncel, Marie-Hélène; Limondin-Lozouet, Nicole; Locht, Jean-Luc; Bahain, Jean-Jacques; Moreno, Davinia; Voinchet, Pierre; Auguste, Patrick; Stoetzel, Emmanuelle; Dabkowski, Julie; Bello, Silvia M.; Parfitt, Simon A.; Tombret, Olivier; Hardy, Bruce


    Dating the earliest human occupations in Western Europe and reconstructing links with climatic and environmental constraints is a central issue in Quaternary studies. Amongst the discovery of Palaeolithic artefacts ascribed to the Early Pleistocene in southeast Britain and central France the Somme Basin, where the Acheulean type-site Amiens Saint-Acheul is located, is a key area for addressing this topic. Research undertaken over the past 20 years on both Quaternary fluvial and loess sequences of this area has provided a unique dataset for the study of the relations between human occupations and environmental variations. Studies based on an interdisciplinary approach combining sedimentology, palaeontology and geochronology have highlighted the impact of the 100 kyrs cycles on terrace formation during the last million years. In this terrace system, the earliest in situ Acheulean settlements known in the 1990s were dated to early MIS 12 (±450 ka), but new field discoveries, at Amiens "Rue du Manège", dated to ± 550 ka, significantly increase the age of the oldest human occupation in the area. In this context, new fieldwork has been undertaken in Abbeville at the Carrière Carpentier site, famous for its White Marl deposit attributed to the Cromerian and in the same terrace level where the former discoveries of "Abbevillian bifaces" were made by d'Ault du Mesnil. This research is based on an interdisciplinary approach, combining sedimentology, paleontology, dating (ESR on quartz and ESR/U-series on teeth) and archaeology. According to the various bio-proxies (molluscs, large vertebrates, small mammals), the White Marl was deposited during the early part of an interglacial phase in an aquatic slow-flowing environment, as emphasized by the development of oncoliths and the presence of fish and aquatic molluscs. The landscape was composed of a mosaic of open bush and forest areas, in which wet and grassy vegetation developed on riverbanks. On the basis of terrace

  3. Investigating the Relationship of Late Pleistocene Terrace Formation and Channel Dynamics within the Texas Gulf Coastal Plain (United States)

    Ellis, T.; Hassenruck-Gudipati, H. J.; Mohrig, D. C.; Goudge, T. A.


    Terrace formation along coastal rivers is often assumed to be a direct result of punctuated sea-level fall. However, it has been experimentally shown that terraces commonly form under conditions of constant base level fall. In addition, it has been demonstrated that migrating channels in a bedrock system with steady state rock uplift can produce similar looking terraces. The lower Trinity River, in East Texas, is an ideal location to study allogenic (punctuated external forcing) versus autogenic terrace-building mechanisms using lidar measurements and OSL depositional age constraints (Gavin, 2005). To understand paleochannel influence on terrace construction, we measured channel characteristics for 27 preserved segments of paleochannels that are late Pleistocene in age and associated with 27 of 34 measured terraces along about 90 km of the modern river. There is no clear clustering of terrace elevation that might be tied to distinct sea level change events. Rather, the range of mean terrace elevations is indicative of a more constant system transformation. Based on lidar measurements, all paleochannels are larger than the modern channel, suggesting a wetter climate or larger watershed. Channel width measurements are used to quantify these changes in paleoflow discharge. Paleochannel width, radius of curvature and terrace slope measurements are used to characterize the movement of an incising channel. Based upon OSL terrace dates (Gavin, 2005), known global climate variations can be compared to discharge estimates and investigated as a predictor of terrace formation. If terrace formation occurred during distinct intervals of sea level fall, terraces with similar calculated paleoflow discharges are expected to plot along specific downstream elevation profiles. Assuming avulsion-driven terrace formation occurs at locations of higher channel sinuosity, the sinuosity of paleochannels on terraces is compared to the sinuosity of the modern river. Higher paleo

  4. Fluvial terrace dating using in situ cosmogenic {sup 21}Ne

    Energy Technology Data Exchange (ETDEWEB)

    Sexton, E. [Univ. of Illinois, Chicago, IL (United States); Caffee, M. [Lawrence Livermore National Lab., CA (United States)


    Through the analysis of cosmic-ray produced radio-genic and stable nuclide concentrations, specifically {sup 21}Ne, we hope to date certain geomorphic features located along the tributaries of the Colorado River in the Eastern Grand Canyon and the Rainbow Plateau located in Utah. During the Quaternary, the Colorado River system was fed by glacial melting and run-off from the Wind River and Colorado Mountain Ranges. Past periods of aggradation allowed the emplacement of terrace features from debris flow activity. By dating such features we can further constrain the timing of key events such as river down cutting, terrace genesis/exposure age, and rates of surface erosion. Knowing the age and elevation of each terrace we can determine an average rate of down cutting of this river system. This, in turn, will offer information regarding alpine glaciation which is a sensitive indicator of global climate change. Studying the relative concentrations of these isotopic species in surface rocks can be useful in researching glacial periodicity and the relationship between solar activity and climate.

  5. Preventing landslides on terraced slopes: A methodological approach in planning and constructing new terraces (United States)

    Ažman Momirski, Lucija


    In everyday practice, the construction of terraces does not follow a premade plan. Consequently, poorly designed and maintained terraces are often significant sediment sources induced by terrace collapse. The purpose of a plan for terrace construction is to arrange terraces according to geological, geomechanical, geodetic, agricultural, and other data. It is possible to anticipate the consequences of these arrangements through carefully considered decisions (about the ratio of the terrace slope, the quantity and direction of soil shifted when constructing terraces, fitting the terrace geometry to the terrain geometry, the width and length of terrace plains, the inclinations of terrace plains, the construction of field roads and turning points, the construction of drainage for removing groundwater, and other factors). Such a methodological approach in planning and constructing new terraces ensures greater stability of terraces, the smallest quantity of earth shifted, and the greatest possible area of usable land. Building terraces is a direct method for preventing landslides. Building terraces according to a plan increases the efficiency of this method. Such an approach is even more important in areas where terraces extend from the top to bottom of slopes. Two case studies from the Mediterranean area are presented: old terraces from Brkini area, where terraces and their slopes have preserved the same form for almost two hundred years, and the planning process for newly constructed terraced vineyards in the Gorizia Hills with post-project monitoring.

  6. Timing of European fluvial terrace formation and incision rates constrained by cosmogenic nuclide dating (United States)

    Schaller, Mirjam; Ehlers, Todd A.; Stor, Tomas; Torrent, Jose; Lobato, Leonardo; Christl, Marcus; Vockenhuber, Christof


    Age constraints of late Cenozoic fluvial terraces are important for addressing surface process questions related to the incision rates of rivers, or tectonic and climate controls on denudation and sedimentation. Unfortunately, absolute age constraints of fluvial terraces are not always possible, and many previous studies have often dated terraces with relative age constraints that do not allow for robust interpretations of incision rates and timing of terrace formation. However, in situ-produced cosmogenic nuclides allow absolute age determination, and hence incision rates, of fluvial deposits back to 5 Ma. Here we present, cosmogenic depth profile dating and isochron burial dating of four different river systems in Europe spanning 12° of latitude. We do this to determine river incision rates and spatial variations in the timing of terrace formation. Isochron burial age constraints of four selected terraces from the Vltava river (Czech Republic) range between 1.00 ± 0.21 to 1.99 ± 0.45Ma. An isochron burial age derived for the Allier river (Central France) is 2.00 ± 0.17Ma. Five terrace levels from the Esla river (NW Spain) were dated between 0.08 + 0.04 / - 0.01Ma and 0.59 + 0.13 / - 0.20Ma with depth profile dating. The latter age agrees with an isochron burial age of 0.52 ± 0.20Ma. Two terrace levels from the Guadalquivir river (SW Spain) were dated by depth profile dating to 0.09 + 0.03 / - 0.02Ma and 0.09 + 0.04 / - 0.03Ma. The one terrace level from the Guadalquivir river dated by isochron burial dating resulted in an age of 1.79 ± 0.18Ma. Results indicate that the cosmogenic nuclide-based ages are generally older than ages derived from previous relative age constraints leading to a factor 2-3 lower incision rates than previous work. Furthermore, the timing of terrace formation over this latitudinal range is somewhat obscured by uncertainties associated with dating older terraces and not clearly synchronous with global climate variations.

  7. Vertical characteristics of the Hani terrace paddyfield ecosystem in Yunnan,China

    Institute of Scientific and Technical Information of China (English)

    Baoshan CUI; Zheyuan YOU; Min YAO


    The Hani terrace paddyfield in Yunnan Province,China is categorized as a 'constructed wetland' under the Lamsar Convention classification.The Hani terrace paddyfield ranges from an altitude of 144 to 2000 m above sea level (ASL) in the southern slopes of the Ailao Mountains,angling down at a range of 15°to 75°.In this study,we investigated the ecosystem of the terrace paddyfields in the Mengpin and Quanfuzhuang administrative villages located at the center of the cultural heritage conservation district in the Hani terrace paddy-field.The Hani terrace paddyfield ecosystem structure is "forest-village-terrace paddyfield-river" in the order of descending altitude.Soil and water samples were sequen-tially taken from forests,villages and the terrace paddy-fields to be able to study the vertical characteristics of Hani's terrace paddyfields.PO4-P and NH3-N in water were measured to test for water contamination.Seven soil nutrient factors were tested,including organic material (OM),char and nitrogen ratio (C/N),pH,total nitrogen (TN),total phosphorus (TP),available phosphorus (AP),and available potassium (AK).Soil quality was also eval-uated using the characteristics of the soil nutrient factors.Vertical changes in the landscape,wetland types,wetland plants,hydrology and soil nutrients were characterized.Results showed that:(1) Hani's terrace paddyfield can be divided into five types of wetlands; the rice varieties and cultivation patterns vary in each type of wetland.(2) Hani's terrace paddyfield has a great capacity for water conservation and a strong ability to purify contaminants.The impoundage of Hani's terrace paddyfield is about 5050 m3/hm2.Contaminants in the terrace paddyfield soils decrease exponentially with the decline in altitude.(3) Comparison of soil quality in five different land use types indicates decreasing soil quality from forest to ter-race land to terrace paddyfield to water source.Except for headwater soil,single factors such as OM,TN and TP

  8. Galveston Bay Marsh Terracing 2001-2002 (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Marsh terracing is used to restore coastal wetlands by converting shallow nonvegetated bottom to intertidal marsh. Terraces are constructed from excavated bottom...

  9. CERN gets a new terrace

    CERN Multimedia

    Laëtitia Pedroso


    For the last few days, people working on the CERN site have been able to take advantage of the new terrace to relax on and make the most of the nice weather. What more could you ask for in your work place?   New terrace between building 39 and 40 As part of the programme of renewal and improvement of CERN's green areas, the GS Department entrusted Genève Espaces Verts, the company responsible for their upkeep and management, with the creation of a new terrace between Buildings 39 and 40. The terrace, which is made of a wood selected for its ability to withstand variations in temperature, is shady in the mornings and in the full sun from midday onwards. It can seat about a hundred people. Users can now unwind or drink their coffee at leisure in a peaceful and harmonious setting surrounded by flowers. Even here, though, physics is never far away: the flower pots made from the protective end-caps of the LHC magnets serve as a reminder of what we are all here for.     &...

  10. On the potential for regolith control of fluvial terrace formation in semi-arid escarpments (United States)

    Norton, K. P.; Schlunegger, F.; Litty, C.


    Cut-fill terraces occur throughout the western Andes, where they have been associated with pluvial episodes on the Altiplano. The mechanism relating increased rainfall to sedimentation is, however, not well understood. Here, we apply a hillslope sediment model and reported cosmogenic nuclide concentrations in terraces to examine terrace formation in semi-arid escarpment environments. We focus on the Pisco river system in western Peru in order to determine probable hillslope processes and sediment transport conditions during phases of terrace formation. Specifically, we model steady-state and transient hillslope responses to increased precipitation rates. The measured terrace distribution and sediment agree with the transient predictions, suggesting strong climatic control on the cut-fill sequences in western Peru primarily through large variations in sediment load. Our model suggests that the ultimate control for these terraces is the availability of sediment on the hillslopes, with hillslope stripping supplying large sediment loads early in wet periods. At the Pisco river, this is manifest as an approximately 4-fold increase in erosion rates during pluvial periods. We suggest that this mechanism may also control terrace occurrence other semi-arid escarpment settings.


    Institute of Scientific and Technical Information of China (English)

    郑荣章; 徐锡伟; 马文涛; 李建平


    通过对阿尔金断裂带西段莫勒切河河口附近卫星影像解译、野外调查测量及地貌面样品年龄测定,利用宽谷阶地、堆积阶地获取构造隆升速率、构造变形方式及加积速率,并结合区域气候资料探讨该区阶地发育对气候变化的响应.莫勒切河出山口发育4级阶地(T,T,T,T),其中T、T为宽谷阶地,T为堆积阶地,T.为堆积一切割阶地.T,T,T阶地形成年龄为分别为(18.98±1.42)ka BP、(13.08±1.01)ka BP、(5.72±0.43)ka BP,3级阶地分别形成于冰盛期末期、新仙女木时期以及5ka BP左右的变冷变干气候环境.T揭示自(18.98±1.42)ka BP至今莫勒切河出山口的平均抬升速率为(6.66±0.50)mm/a.T、T阶地的存在揭示(18.98±1.42)ka BP至(13.08±1.01)ka BP之间,研究区及其邻近地区存在一轮快速的构造抬升和快速加积事件,抬升速率>20mm/a,加积速率>10mm/a.构造抬升形式为从南向北的跨阿尔金断裂带的掀斜式抬升,是高原向北扩展的一种运动形式.T阶地的堆积应该是此次快速构造抬升和15ka BP至12ka BP之间冰消气候共同作用的产物.%Based on the interpretation of satellite image, field investigation and geomorphic survey and sample dating of surface, the strath terrace and fill terrace at the outlet of Moleqiehe River on the western segment of Altyn Tagh Fault zone(ATF) are used to study the tectonic uplift rate, uplift model and aggradation rate,and cooperated with data of the regional climate, the response to climate evolution of development of terrace are discussed.The previous studies of the terraces related with the Altyn Tagh Fault zone are mainly focused on the horizontal offset in order to obtain sinistral-slip rate, but few studies involve the uplift using terraces. As a structural zone with strike-thrust characteristic, the ATF is a boundary structure of the northern fringe of Qinghai-Tibet Plateau, and its thrusting and uplifting movement is of significance for


    Directory of Open Access Journals (Sweden)

    J. RUHL


    Full Text Available 189 phytosociological relevés have been made in five areas of Sicily, three on volcanic substrates and two on limestones, to study plant community succession trends within abandoned terraced vineyards and cereal fields. Disturbance status and abandonment age was recorded for each sample plot. DCA of these relevés suggests that four are the most important factors driving succession, i.e. geological substrate, bioclimate, age of abandonment and disturbance. In most cases - if there are some dispersal centres near the old fields - undisturbed and less disturbed terraces evolve quite rapidly towards the local potential “climax” community. Different trends have been recorded on the areas which underwent and still undergo frequent and severe disturbance: succession is biased or even blocked in a steady state, so that grassland, garrigue, mantle or herb-dominated communities prevail. The species composition of the plant communities subject to disturbance seems to be strongly connected with the time gap between abandonment and first disturbance occurrence. The “mixed” ecological-structural-phytosociological approach here adopted to describe plant communities was quite effective to interpret abandoned terraces communities and their dynamism.


    Directory of Open Access Journals (Sweden)

    J. RUHL


    Full Text Available 189 phytosociological relevés have been made in five areas of Sicily, three on volcanic substrates and two on limestones, to study plant community succession trends within abandoned terraced vineyards and cereal fields. Disturbance status and abandonment age was recorded for each sample plot. DCA of these relevés suggests that four are the most important factors driving succession, i.e. geological substrate, bioclimate, age of abandonment and disturbance. In most cases - if there are some dispersal centres near the old fields - undisturbed and less disturbed terraces evolve quite rapidly towards the local potential “climax” community. Different trends have been recorded on the areas which underwent and still undergo frequent and severe disturbance: succession is biased or even blocked in a steady state, so that grassland, garrigue, mantle or herb-dominated communities prevail. The species composition of the plant communities subject to disturbance seems to be strongly connected with the time gap between abandonment and first disturbance occurrence. The “mixed” ecological-structural-phytosociological approach here adopted to describe plant communities was quite effective to interpret abandoned terraces communities and their dynamism.

  14. Terrace styles and timing of terrace formation in the Weser and Leine valleys, northern Germany: Response of a fluvial system to climate change and glaciation (United States)

    Winsemann, Jutta; Lang, Jörg; Roskosch, Julia; Polom, Ulrich; Böhner, Utz; Brandes, Christian; Glotzbach, Christoph; Frechen, Manfred


    In glaciated continental basins accommodation space is not only controlled by tectonics and sea-level but also by the position of ice-sheets, which may act as a regional base-level for fluvial systems. Although the Pleistocene terrace record of major river systems in northwestern Europe has been investigated by many authors, relatively little attention has been paid to base-level changes related to glacier advance-retreat cycles and how these regional changes in base-level interacted with river catchment processes. This study provides a synthesis of the stratigraphic architecture of Middle Pleistocene to Holocene fluvial terraces in the upper Weser and middle Leine valley in northern Germany and links it to glaciation, climate and base-level change. The depositional architecture of the fluvial terrace deposits has been reconstructed from outcrops and high-resolution shear wave seismic profiles. The chronology is based on luminescence ages, 230Th/U ages, 14C ages and Middle Palaeolithic archaeological assemblages. The drainage system of the study area developed during the Early Miocene. During the Pleistocene up to 170 m of fluvial incision took place. A major change in terrace style from strath terraces to cut-and-fill terraces occurred during the early Middle Pleistocene before Marine Isotope Stage MIS 12, which may correlate with climate deterioration and the onset of glaciation in northern central Europe. During this time a stable buffer zone was established within which channels avulsed and cut and filled freely without leaving these vertical confines. Climate was the dominant driver for river incision and aggradation, whereas the terrace style was controlled by base-level changes during ice-sheet growth and decay. A major effect of glacio-isostatic processes was the post-Elsterian re-direction of the River Weser and River Leine. The Middle Pleistocene fluvial terraces are vertically stacked, indicating a high aggradation to degradation ratio, corresponding

  15. Closure of LG-1 reservoir across a sensitive clay terrace

    Energy Technology Data Exchange (ETDEWEB)

    Schneeberger, C.E.; Levay, J.; Boncompain, B.


    The development of the LG-1 hydroelectric project requires the construction of a 2 km long dyke across a clay terrace. The nominal crest elevation of the dyke is 35 m and will confine the proposed LG-1 reservoir at elevation 32 m. Most of the dyke is of the freeboard type except for its northern extremity where the dyke reaches a height of 10.5 m. The sensitive nature of the soft clay foundation has called for several design features to assure the stability of the dyke along with both upstream and downstream bank stabilization work in order to avoid the occurence of potentially disastrous retrogressive slides. Such slides are typical of La Grande River clay banks and may reach 1-2 km in lateral extent. The paper describes the geotechnical conditions of the clay terrace and presents the most significant design criteria that were adopted.

  16. The impact of the streamflow hydrograph on sediment supply from terrace erosion (United States)

    Higson, John Lee; Singer, Michael Bliss


    Sediment supply from banks and terraces has important implications for grain-size distributions in alluvial rivers (and by extension for aquatic habitat), as well as for the delivery of floodplain-stored nutrients and contaminants to the aquatic environment. The interactions between streamflow hydrographs and lateral channel boundary failure control the sediment supply from banks and terraces. However, the relationships between variable flow and discrete sediment supply from catastrophic erosion of lateral boundaries and subsequent mass sediment flux in rivers are not well characterised by existing methods and models that focus only on one of several relevant interrelated processes. In order to improve predictive capability of catastrophic sediment supply from lateral boundaries, we adopt a new approach to modelling the process interactions between stream hydrology, erosion of banks/terraces, and the corresponding discrete supply of sediment to channels. We develop a modelling framework for terrace - channel coupling that combines existing theories of flow through porous media, bank stability, and fractional sediment flux. We demonstrate the utility of this modelling approach by assessing hydrologically driven erosion, evolution of grain size in the channel, and fine sediment flux from a study site along the Yuba River in California over individual flood hydrographs and over decadal historical flow series. We quantify the supply of sediment eroded from a contaminated nineteenth century fan terrace of hydraulic gold mining tailings intersecting the Yuba, and find that a threshold for erosion exists at a stage in the channel in excess of 8 m producing episodic sediment concentrations in excess of 300 mg L-1. The modelling produced erosion and fine sediment pulses from each of three major floods in the past several decades until the flow drops below 500 m3 s-1 and a bed armor layer forms, while no sediment was generated from the terrace during smaller floods. We

  17. Terrace Layout Using a Computer Assisted System (United States)

    Development of a web-based terrace design tool based on the MOTERR program is presented, along with representative layouts for conventional and parallel terrace systems. Using digital elevation maps and geographic information systems (GIS), this tool utilizes personal computers to rapidly construct ...

  18. Combining information preserved in fluvial topography and strath terraces to extract rock uplift rates in the Apennines (United States)

    Fox, M.; Brandon, M. T.


    Longitudinal river profiles respond to changes in tectonic uplift rates through climate-modulated erosion. Therefore, rock uplift rate information should be recorded in fluvial topography and extracting this information provides crucial constraints on tectonic processes. In addition to the shape of the modern river profile, paleo-river profiles can often be mapped in the field by connecting strath terraces. These strath terraces act as markers that record complex incision histories in response to rock uplift rates that vary in space and time. We exploit an analytical linear solution to the linear version (n=1) of the stream-power equation to efficiently extract uplift histories from river networks and strath terraces. The analytical solution is based on the transient solution to the linear version (n=1) of the stream-power equation. The general solution to this problem states that the elevation of a point in a river channel is equal to the time integral of its uplift history, where integration is carried out over the time required for an uplift signal to propagate from the baselevel of the river network to the point of interest. A similar expression can be written for each strath terrace in the dataset. Through discretization of these expressions into discrete timesteps and spatial nodes, a linear system of equations can be solved using linear inverse methods. In this way, strath terraces and river profiles can be interpreted in an internally consistent framework, without the requirement that the river profile is in a steady state. We apply our approach to the Northern Apennines where strath terraces have been extensively mapped and dated. Comparison of our inferred rock uplift rate history with modern rock uplift rates enables us to distinguish short-term deformation on a buried thrust fault with long-term mountain building processes.

  19. First Terraced Field Builders in China?

    Institute of Scientific and Technical Information of China (English)


    People of other ethnic groups who have lived in the same mountains with Hanis share all the same natural conditions above mentioned,then why have only the Hani people created the most spectacular landscape of terraced fidlds?

  20. Surveying of the deformed terraces and crust shortening rate in the northwestern Tarim Basin: Comment

    Institute of Scientific and Technical Information of China (English)


    @@ The paper of Shen et al., entitled "Surveying of the deformed terraces and crust shortening rate in the northwest Tarim Basin", was published in Chinese Science Bulletin (Vol. 46, No. 12)[1]. Shen et al. found the deformation of Late Pleistocene to Holocene terraces of the Boguzi River across the Artushi Anticline in the northwest Tarim Basin close to the Pamir, and made level survey and differential GPS measurement, which is of great importance to geodynamics for research on the coupling of Tianshan Mountains uplifting and Tarim Basin depression. But their understanding to the deformation mechanics of terraces and the calculation methods of crustal shortening are open to discussion. Therefore, we discuss it with Shen Jun et al.

  1. Fluvial terrace formation along Wyoming's Laramie Range as a response to increased late Pleistocene flood magnitudes (United States)

    Hanson, Paul R.; Mason, Joseph A.; Goble, Ronald J.


    This study evaluates the potential climatic mechanisms involved in fluvial terrace genesis along Wyoming's Laramie Range. We used optical dating methods to determine depositional ages for fluvial fills, and to calculate incision rates for terrace suites along two of the region's larger rivers. Optical ages were determined for the five lowest terrace levels (T5-T1) which were deposited at ˜ 59.6, 39.2, 26.3, 22.7, and 18.5 ka, and incision rates calculated for the two rivers were ˜ 0.29-0.34 m/kyr over the last ˜ 60 kyr. The formation of fluvial terraces in the central Rocky Mountains is commonly attributed to climatically induced changes in sediment input. According to most studies, relatively low incision rates existed during the colder periods of the Pleistocene due to high stream sediment loads, but terraces were formed during warmer interglacial periods when reduced sediment availability facilitated higher incision rates. However, this conceptual model cannot explain the incision records presented here, which show that the streams incised 9-10 m in two to three events during Oxygen Isotope Stage 2, but only 1-2 m during the warmer climates of the last ˜ 18.5 ka. The stream power model we adapted to this setting suggests that late Quaternary streams operated under two basic states. During the colder conditions of the Pleistocene, higher flood magnitudes resulted in higher lateral erosion and incision rates. However, the lower stream discharge common to the warmer interglacial periods resulted in relatively inactive streams when both lateral erosion and incision rates were lowered. This model can explain the high incision rates during the cold conditions of Oxygen Isotope Stage 2, the occurrence of terrace fill ages near cold to warm transitions, and the apparent acceleration in incision rates toward the end of the last glacial cycle. Finally, this study suggests that terrace fill ages and incision rates are similar for the distally glaciated Laramie River

  2. Contrasted terrace systems of the lower Moulouya valley as indicator of crustal deformation in NE Morocco (United States)

    Rixhon, Gilles; Bartz, Melanie; El Ouahabi, Meriam; Szemkus, Nina; Brueckner, Helmut


    The Moulouya river has the largest catchment in Morocco and drains an area which is characterized by active crustal deformation during the Late Cenozoic due to the convergence between the African and Eurasian plates. As yet, its Pleistocene terrace sequence remains poorly documented. Our study focuses on the lowermost reach of the river in NE Morocco, which drains the Triffa sedimentary basin directly upstream of the estuary. New field observations, measurements and sedimentological data reveal contrasted fluvial environments on either side of a newly identified thrust zone, which disrupts the whole sedimentary basin and is associated with N-S compressive shortening in this region (Barcos et al., 2014). Long-lasting fluvial aggradation, materialized by ≥37 m-thick stacked fill terraces, and the development of a well-preserved terrace staircase, with (at least) three Pleistocene terrace levels, occur in the footwall and the hanging wall of the thrust, respectively. Same as for the Pleistocene terrace sediments of the middle Moulouya, a recurrent sedimentary pattern, characterized by fining-upward sequences was observed in the studied terrace profiles. Assessing the rates of crustal deformation along this main thrust zone requires age estimations for these Pleistocene terrace deposits of the lower Moulouya on each side of the thrust. Samples for luminescence (OSL/IRSL), electron spin resonance (ESR, on quartz) and cosmogenic nuclide dating (26Al/10Be, burial dating) were collected in terrace deposits located both in the foot- and hanging walls. Sample preparation and analysis as well as age determination are in progress. The preliminary data mentioned above, soon to be completed by chronological data, agree well with morphometric indicators stating that the whole Moulouya catchment is at disequilibrium state (Barcos et al., 2014). This is confirmed by several knickpoints in its longitudinal profile. Late Cenozoic uplift associated with crustal shortening, which

  3. Chronostratigraphical investigations on Pleistocene fluvioglacial terraces of NW-Austria (United States)

    Terhorst, B.


    Investigations on paleopedology and Quaternary stratigraphy were carried out in the area of fluvioglacial terraces of the rivers Inn and Traun/Enns. Research projects have been financed by the German Research Foundation (DFG) and the ICSU Grant Programme. Detailed studies were carried out on paleosols and loess sequences of different ages. The investigations of the research group were focused on loess/paleosol sequences located on top of Riss terraces (OIS 6 and older) as well as in areas with Mindel and Günz terraces. Loess records of the last glacial/interglacial cycle can be well observed in the study areas. Generally, the Eemian soil (O/S 5e) is developed as a reddish Bt-horizon in fluvioglacial gravels. U/Th-datings of calcites in the fluvioglacial sediments are indicating that soil formation took place in the catchment area about 113.000 ± 4.400 ka (Terhorst et al., 2002). The interglacial paleosol was truncated and a redeposited colluvial layer was deposited on top of the Bt-horizons containing charcaol with characteristic relicts of coniferous trees. After this land surface destabilisation phase, sedimentation of loess became the predominant process. Pedogenesis in form of a brown paleosol occurred, which partly has been redeposited. The pedocomplex is characterized by intense bioturbation of steppe animals. OSL-datings show that this part of the sequence belong to the Middle Würmian stage. The pedocomplex is overlain by a Cambisol corresponding to the youngest Middle Würmian interstadial. The paleosol is covered by thick loess deposits of the Upper Pleniglacial. Well-developed Tundragleysols subdivide the loess deposits. The uppermost soil corresponds to the Holocene Luvisol that includes hydromorphic properties. Older fluvioglacial terraces of Mindel and Günz age (in the classical stratigraphy) show a completely different structure of the covering layers (c.f. Kohl, 1999). In this case, several thick interglacial paleosols are embedded within records

  4. Ostracoda from Vestfold Hill lake terraces, Antarctica

    Digital Repository Service at National Institute of Oceanography (India)

    Setty, M.G.A.P.

    Six species of ostracodes are recorded from two transects of terraces of Deep Lake, Vestfold Hills, Antarctica. Two species (@iXesteleberis@@ sp. and @iBradleya dictyon@@) range from Cretaceous to Recent, @iPoseidonamicus aff. P. major@@ ranges from...

  5. Spatial analysis of fluvial terraces in GRASS GIS accessing R functionality (United States)

    Józsa, Edina


    Terrace research along the Danube is a major topic of Hungarian traditional geomorphology because of the socio-economic role of terrace surfaces and their importance in paleo-environmental reconstructions. Semi-automated mapping of fluvial landforms from a coherent digital elevation dataset allow objective analysis of hydrogeomorphic characteristics with low time and cost requirements. New results obtained with unified GIS-based algorithms can be integrated with previous findings regarding landscape evolution. The complementary functionality of GRASS GIS and R provides the possibility to develop a flexible terrain analysing tool for the delineation and quantifiable analysis of terrace remnants. Using R as an intermediate analytical environment and visualisation tool gives great added value to the algorithm, while GRASS GIS is capable of handling the large digital elevation datasets and perform the demanding computations to prepare necessary raster derivatives (Bivand, R.S. et al. 2008). The proposed terrace mapping algorithm is based on the work of Demoulin, A. et al. (2007), but it is further improved in the form of GRASS GIS script tool accessing R functionality. In the first step the hydrogeomorphic signatures of the given study site are explored and the area is divided along clearly recognizable structural-morphological boundaries.The algorithm then cuts up the subregions into parallel sections in the flow direction and determines cells potentially belonging to terrace surfaces based on local slope characteristics and a minimum area size threshold. As a result an output report is created that contains a histogram of altitudes, a swath-profile of the landscape, scatter plots to represent the relation of the relative elevations and slope values in the analysed sections and a final plot showing the longitudinal profile of the river with the determined height ranges of terrace levels. The algorithm also produces a raster map of extracted terrace remnants. From this

  6. Characterization of seven United States coal regions. The development of optimal terrace pit coal mining systems

    Energy Technology Data Exchange (ETDEWEB)

    Wimer, R.L.; Adams, M.A.; Jurich, D.M.


    This report characterizes seven United State coal regions in the Northern Great Plains, Rocky Mountain, Interior, and Gulf Coast coal provinces. Descriptions include those of the Fort Union, Powder River, Green River, Four Corners, Lower Missouri, Illinois Basin, and Texas Gulf coal resource regions. The resource characterizations describe geologic, geographic, hydrologic, environmental and climatological conditions of each region, coal ranks and qualities, extent of reserves, reclamation requirements, and current mining activities. The report was compiled as a basis for the development of hypothetical coal mining situations for comparison of conventional and terrace pit surface mining methods, under contract to the Department of Energy, Contract No. DE-AC01-79ET10023, entitled The Development of Optimal Terrace Pit Coal Mining Systems.

  7. An online planning tool for designing terrace layouts (United States)

    A web-based conservation planning tool, WebTERLOC (web-based Terrace Location Program), was developed to provide multiple terrace layout options using digital elevation model (DEM) and geographic information systems (GIS). Development of a terrace system is complicated by the time-intensive manual ...

  8. Living terraced landscapes: Exploring the viability of mountain terraced vineyards in Cyprus (United States)

    Zoumides, Christos; Giannakis, Elias; Bruggeman, Adriana; Camera, Corrado


    Dry-stone terracing is an intensive cultivation practice that has been implemented for centuries in the Mediterranean region. The Troodos Ophiolite Complex on the island of Cyprus covers an area of 2332 km2 with 31% mean slope gradient, and consists of 140 small communities with a total population of around 50,000 inhabitants. Agriculture is practiced on dry-stone terraces with narrow (1-3 m) to medium-base (3-6 m) bench, constructed by cutting and filling in slopes with gradient between 20 and 40%. The main crop grown on terraces is wine grapes. However, many of the vineyards on terraced hillsides are being gradually abandoned and dry-stone walls remain unmaintained, causing a domino effect of collapsing terraces and leading to soil erosion and sedimentation of downstream infrastructure. The main reasons for the gradual decline of terraced landscapes are the ageing of farming population, the depopulation and marginalization of Troodos communities, the small size of agricultural plots, the high cost of labour and the loss of know-how on dry-stone wall maintenance. Despite these socio-economic issues, policy reforms, especially after the accession of Cyprus to the European Union in 2004, have created new challenges and opportunities, and have focused on improving the viniculture's quality rather than quantity. The new appellation of origin launched in 2007 that define where the wine-grapes are grown, as well as the incentives to create small regional wineries, helped maintain the population of some communities and the vine cultivations on dry-stone terraces. The aim of this study is to analyse the determinants of success or failure in sustaining the terraced vineyards in Cyprus. More precisely, the study explores the characteristics that determine the investment (or not) in terrace maintenance and analyses the interlinkages between farming practices and business strategies. The analysis is based on grape and wine production cost data that is acquired by interviews

  9. Increasing Mississippi river discharge throughout the twenty-first century influenced by changes in climate, land use and atmospheric CO2 (United States)

    Tao, B.; Tian, H.; Ren, W.; Yang, J.; Yang, Q.; He, R.; Cai, W. J.; Lohrenz, S. E.


    Previous studies have demonstrated that changes in temperature and precipitation (hereafter climate change) would influence river discharge, but the relative importance of climate change, land use, and elevated atmospheric CO2 have not yet been fully investigated. Here we examined how river discharge in the Mississippi River basin in the 21st century might be influenced by these factors using the Dynamic Land Ecosystem Model driven by atmospheric CO2, downscaled GCMs climate and land use scenarios. Our results suggest that river discharge would be substantially enhanced (10.7-59.8%) by the 2090s compared to the recent decade (2000s), though large discrepancies exist among different climate, atmospheric CO2, and land use change scenarios. Our factorial analyses further indicate that the combined effects of land use change and human-induced atmospheric CO2 elevation on river discharge would outweigh climate change effect under the high emission scenario (A2) of Intergovernmental Panel for Climate Change. Our study offers the first attempt to project potential changes in river discharge in response to multiple future environmental changes. It demonstrates the importance of land use change and atmospheric CO2 concentrations in projecting future changes in hydrologic processes. The projected increase river discharge implies that riverine fluxes of carbon, nutrients and pesticide from the MRB to the coastal regions would increase in the future, and thus may influence the states of ocean acidification and hypoxia and deteriorate ocean water quality. Further efforts will also be needed to account for additional environmental factors (such as nitrogen deposition, tropospheric ozone pollution, dam construction, etc.) in projecting changes in the hydrological cycle.

  10. Sensitivity of discharge and flood frequency to twenty-first century and late Holocene changes in climate and land use (River Meuse, northwest Europe)

    NARCIS (Netherlands)

    Ward, P.J.; Renssen, H.; Aerts, J.C.J.H.; Verburg, P.H.


    We used a calibrated coupled climate–hydrological model to simulate Meuse discharge over the late Holocene (4000–3000 BP and 1000–2000 AD). We then used this model to simulate discharge in the twenty-first century under SRES emission scenarios A2 and B1, with and without future land use change. Mean

  11. OSL dating of fluvial terraces for incision rate estimation and indication of neotectonic activity in Pamir (United States)

    Fuchs, M. C.; Gloaguen, R.; Krbetschek, M.; Szulc, A.


    ThePamir owes its special attraction for geo-scientists to being among Earth's largest intra-continental orogens and to display some of the highest uplift rates as well as to host among the most powerful river systems on the planet. The evolution of the drainage network as a proxy for the landscape's response to tectonic signals provides a powerful tool to study neotectonics. The relation between tectonic forcing and surface response is indicated by structural anomalies (e.g. river-capture, river-reversal or -deflection) and spatial differences of process rates (e.g. incision rates). We combine OSL dating with remote sensing tectonic geomorphology in order to determine the zones of active deformation in the Quaternary. The local drainage system of the study region aligns mainly to the east-west-trending belts of shortening, which results from the ongoing northward propagation of the Indian plate. In contrast the major trunk river, the Panj, is unusual in that it deflects northwards and then doubles back to the southwest, cutting the southern and central Pamir doming and several other major Cenozoic deformation zones. We use fluvial terraces along the deflected north-south orientated part including the doubled back prolongation of the more or less normal orientated Panj. These sediment bodies are used as a geomorphic record to reveal changes in the balance between sediment flux and discharge. Dating these fluvial terraces by OSL provides the burial ages of the sediments indicating periods of sedimentation. The remains of those periods are far from equally distributed and mark the time of local conditions for sedimentation as especially the close neighbourhood of most of the terraces from the two youngest periods demonstrate. Precise measurements of the heights of the dated terraces with respect to the present river level based on relative kinematic GPS quantify the total vertical incision of the river subsequent to the sedimentation and abandonment. Incision rates

  12. Taxonomic and environmental soil diversity of marine terraces of Gronfjord (West Spitsbergen island) (United States)

    Alekseev, Ivan; Abakumov, Evgeny


    Soil surveys in polar region are faced to problems of soil diagnostics, evolution, geography and pedogenesis with the aim to assess the actual state and future dynamics of soil cover under changing environmental conditions. This investigation is devoted to specification of taxonomic and environmental soil diversity of marine terraces of Gronfjord (Svalbard archipelago, West Spitsbergen Island). It was established 3 key plots (Grendasselva, Aldegonda rivers and marine terrace in surroundings of Barentsburg aerodrome). Soil diagnostics was carried out according to Russian soil classification system and WRB. Grendasselva river valley is characterized by numerous patterned ground elements combined with lichen-moss and moss-lichen patches with sporadic inclusions of higher plants (mostly Lusula pilosa). Soil cover is represented by Typic Cryosols on elevated sites and Histic Gleysols, Turbic Gleysols and Histosols on well-drained boggy sites. Aldegonda river valley characterizes by predominance of entic soils (soil with non-pronounced profile differentiation) on moraine material (mostly Cryic Leptosols). Vegetation is presented by sporadic plant communities comprised by Lusula pilosa and thin lichen-moss ground layer (developed only in well-moistened micro depression). Marine terrace in surroundings of Barentsburg aerodrome is covered by moss-lichen tundra with sporadic inclusions of Lusula pilosa. On the top of the terrace compressed barren circles are quite abundant. Soil catena has been established within this key plot. Soil types are represented by Typic Cryosols in watershed parts of catena, Gleysols and Histic Gleysols in accumulation positions. The active layer depths have been distinguished using vertical electrical sounding. They ranged from 80-90 cm at Grendasselva and Aldegonda river key plot to 140-150 cm at marine terrace in surroundings of Barentsburg aerodrome. Regional differences in this indicator may be explained not only by local differences in

  13. Strath terraces on the western High Plains indicate climatically-driven variations in sediment supply from source basins in the Colorado Front Range (United States)

    Foster, M. A.; Dühnforth, M.; Anderson, R. S.


    Large strath terraces adjacent to the Colorado Front Range record the local history of fluvial planation and incision into the erodible rocks of the Denver basin over the last 2 million years. Terrace surfaces have been correlated into ~6 alluvial units using elevation and soil development; each alluvial unit was thought to represent a fairly consistent elevation of the Denver basin during various stages of exhumation, driven by base-level fall of the South Platte River. Here we show instead that (1) strath terraces in the western High Plains cannot be correlated based on elevation alone and (2) exhumation of the Denver basin is likely spatially and temporally variable due to climatically-driven variations in sediment supply from the source basins. We collected samples for cosmogenic radionuclide (CRN) profiles (10Be and 26Al) and a soil chronosequence from three strath terraces adjacent to Lefthand Creek near Boulder, CO. 10Be profile data on the upper- and middle-elevation terraces yield dates of 95 ka and 91 ka; these dates are much younger than the correlative alluvial units to the south of Boulder, which date to 1.5 Ma and 250 ka, respectively. Soils on the upper and middle terraces are similar in soil development and clast weathering, consistent with the narrow time window obtained from CRN dating of the two units. 10Be-derived rates for catchment-wide paleo-denudation are ~8.0 cm/ka from the flat and broad upper-terrace gravels and ~3.5 cm/ka from the steeper and narrower middle-terrace gravels. Young terraces at Lefthand Canyon are more consistent with a model of fluvial incision and aggradation driven by climate-controlled variations in sediment production from source basins in the Front Range. High catchment-wide denudation rates generate a high sediment supply, leading to aggradation and lateral planation. Terrace sediments are likely deposited and eroded multiple times during periods of lateral planation; the most recent occupation is preserved in the

  14. Evolución geomorfológica y cronología relativa de los niveles aterrazados del área adyacente a la desembocadura del río Chubut al Atlántico (Provincia del Chubut Geomorphological evolution and relative chronology of terrace levels adjacent to the Chubut River mouth to the Atlantic (Chubut Province.

    Directory of Open Access Journals (Sweden)

    Emilio F González Díaz


    that is contested. The methodological recognition of the ancient alluvial fan and its genetic and temporary distinction, were made from geomorphologic analysis and altimetric evaluation. Time assignment is a problem not yet solved. The methodology led to three different geomorphic systems or levels related to successive episodes of aggradation and erosion, with increasing lower positions, which coincide with a complex paleodrainage ancient alluvial fan. its successive developments are linked to proposed proto-rivers Chubut 1, 2, 3 and to a Simpson paleo-valley. Despite the mentioned limitations, we propose that the evolutionary model of ancient alluvial fan responds to a structure of cut and fill which is supported by the poly-formational composition of an ancient alluvial fan, and a gradual southward migration of the paleo-drainage. Based on geomorphologic analysis and altimetric distinction an upper level, composed of the remains of three plains (Pa, Pm and Pb, a middle level with two terraces (T1 and T2 and a complex lower level and five terraces (T3, T4, T5 T6 and T7 were recognized. Relict evidences of paleo-drainages are proposed based on the Estancia Paz and Don Morgan-Saraza paleo-valleys in the upper level. The age of the ancient alluvial fan based on the geomorphic evolution of the study area is tentatively assigned to an uncertain period between the late Pleistocene and late Sangamon interglacial at the end of the last glaciation.

  15. Agricultural Terrace Pattern Distribution and Preservation along Climatic Gradient (United States)

    Ackermann, Oren


    Agricultural terraces are a well-distributed agrotechnical method for planting in various places in the world, from ancient time and until today. The aim of the current research is to demonstrate the spatial distribution and conservation of agricultural terraces along a climatic gradient of sub-humid Mediterranean, semi-arid and arid climate zones by presenting the case study of the Land of Israel. In the Judean Mountains (central Israel), a region under sub-humid Mediterranean conditions, agricultural terraces are characterized by terrace coverage on slopes and in valleys. Annual rainfall average in this region is 800 mm, allowing for vast rain-fed agriculture based on direct rain. In the Judean Shephelah (central Israel), a region under semi-arid conditions, agriculture terraces are located in small spots on the slopes, and in terrace fields in the valleys. Annual average rainfall in this region is between 300 and 400 mm. Rain-fed agriculture was sustained by direct rain and additional runoff generated on rock outcrops. In the Negev Highlands, (southern Israel), a region under arid climate conditions with annual rainfall average of 100 mm, runoff farm terraces are located in valleys, and agriculture sustenance was based on water harvesting from the slopes. The terraces pattern distribution is similar to the natural vegetation pattern distribution of the three given areas. During the past ten of years, changes in land use and farming methods have resulted in the abandonment of many agricultural terraces in the given areas. Terrace abandonment leads to the collapse of retaining walls and erosion of soil and sediments from the terrace body with the latter occurring at a high rate in the arid Negev highlands. However, in the Judean Mountains and the Judean Shephelah, areas under sub-humid Mediterranean and semi-arid conditions, the intensity of erosion is lower since the terraces are covered by dense shrubs such as Sarcopoterium spinosum or by trees. This plant cover

  16. A process-based algorithm for simulating terraces in SWAT (United States)

    Terraces in crop fields are one of the most important soil and water conservation measures that affect runoff and erosion processes in a watershed. In large hydrological programs such as the Soil and Water Assessment Tool (SWAT), terrace effects are simulated by adjusting the slope length and the US...

  17. Isochron burial dating of Danube terraces in the course of an interlaboratory comparison on sample preparation in Vienna and Budapest (United States)

    Neuhuber, Stephanie; Ruszkiczay-Rüdiger, Zsófia; Decker, Kurt; Braucher, Regis; Fiebig, Markus; Braun, Mihály; Häuselmann, Philipp; Aster Team


    The Neogene development of the Vienna Basin's tectonic history is well-documented in seismic sections and hydrocarbon wells. The late Neogene to Quaternary history is less well preserved due to a gap in the sediment record starting from the Late Pannonian due to a large-scale uplift during a phase of basin inversion [1]. Quaternary sediments in the Vienna Basin form prominent Pleistocene terraces north and south of the Danube's recent floodplain. The Danube's course currently shifts to the south where it erodes into its own gravel terraces that were presumably accumulated during the Pliocene and Early to Middle Pleistocene. North of the Danube, a wide alluvial plain has developed with one prominent Middle Quaternary terrace level 17-25 m above the river (Gänserndorf and Schlosshof Terraces). The most recent tectonic events related to the sinistral movement of the Vienna Basin transform fault system are recorded north of the Danube by faulted terrace segments that were identified by paleoseismological trenching in combination with OSL [2]. In contrast, terraces south of the Danube form a staircase with altitudes ranging between 25 and 130 m above todays water level. The terraces in the south have also been strongly dissected by faults [3], each fault block preserved a slightly different succession of terraces. The fault-related vertical displacements south of the Danube have not yet been quantified. To better understand the Quaternary terrace sequence and its displacement in the southern zone, we use the cosmogenic nuclide pair of 26Al and 10Be for isochron burial dating of a Danube terrace at Haslau an der Donau (~40 m above river level). This terrace is locally the lowest of a staircase of a total of 6 different levels. Based on published geomorphological works, the expected age is Middle Pleistocene. The isochron burial dating method is therefore well-suited to date this sedimentary setting due to the presence of large individual clasts that share the same post

  18. 26Al/10Be burial ages for a Pleistocene terrace in the Vienna Basin, Austria (United States)

    Braumann, S.; Fiebig, M.; Neuhuber, S.; Schaefer, J. M.; Haeuselmann, P.; Schwartz, R.; Finkel, R. C.


    The Vienna Basin in the northeastern part of Austria between the Eastern Alps and the West Carpathians is a pull-apart basin crossed by the Danube river. The structure is filled with marine and terrestrial sediments showing thicknesses of up to 6 km. An increase in glacial melt water discharges, typically linked to high productivity of Alpine glaciers, had an essential impact on the formation of the investigated terrace. The scale of erosion and sediment transport translates to deposition rates in the foreland and is influenced by the magnitude of melt water discharges in Alpine catchment areas. Variations in layer characteristics (i.e. grain size, sorting, thickness) are an indicator for glacial pulses. Burial dates of ten quartz pebbles originating from the Gaenserndorfer terrace, situated in the northeastern part of the basin, set time dependent constraints on the required hydrological regime for mobilization, transport and sedimentation of bedloads and allow relating the deposition of glacial sediments to past glacial periods. But the geomorphic evolution of the Vienna Basin was not only determined by sedimentation processes. A number of irregularities manifest that tectonics affected the area as well: Terrace tilts are dipping against the slope of the Danube and offsets of some decameters between sediment layers showing the same facies, but located several kilometers apart from each other, could be identified. An extensive Miocene fault system was partly reactivated during the Middle Pleistocene and could have caused the formation of these discontinuities. It is of great interest to discriminate impacts on the area due to deposition from morphological elements formed by seismic events. The preliminary burial ages afford for putting the sampled terrace segment into a coherent geochronological context and provide a dataset to compare ages of the Gaenserndofer terrace to ages of sediment layers at other locations within the basin in order to either validate or

  19. Geomorphometric Analysis of Debris Flow Terraces at Mount Rainier, WA Using Spacecraft Acquired Topography (United States)

    Hubbard, B. E.; Crowley, J. K.; Mars, J.; Bursik, M. I.


    Methods used in extracting digital topography from remote sensing data include photogrammetry, interferometry, altimetry and photoclinometry. Two recent spaceborne missions use some of these methods for generating global DEM coverages at horizontal resolutions less than 100 m per pixel. This study evaluates and compares the utility of such data for estimating inundation levels of past debris flows based on the upslope heights and cross-sectional extents of terraces preserved in river valleys. Deposits from Mount Rainier representing debris flow volumes spanning several orders of magnitude are used as case examples for testing this idea. ASTER DEMs are derived photogrammetrically by measuring the parallax between a stereo pair of images acquired simultaneously by nadir- and aft-viewing instruments. The two channels used (3N and 3B) have near-infrared bandwidths of 0.76-0.86 microns and a base/height ratio of 0.6 for the stereo pair. SRTM DEMs are currently being produced interferometrically from C- (5.6 cm wavelength) and X-band (3 cm wavelength) synthetic aperture radar (SAR) by measuring the phase differences between SAR images acquired by two antennas spaced 60 m apart. Terraces of the Electron mudflow, National lahar, and Tahoma lahar deposits were all resolved in cross-sectional profiles extracted from the ASTER DEM. These profiles were compared to profiles from a level 2 USGS DEM that was corrected for systematic errors such as canopy, and resampled to the 30 m resolution of the ASTER DEM. The ASTER DEM was co-registered to the USGS DEM, which will later be co-registered to the SRTM DEM when it becomes available. About 28 km downstream of Mount Rainier, both datasets reveal a terrace of the Electron mudflow at least 25 m high above the channel of the Puyallup River. The ASTER DEM appears to resolve tributary drainages more clearly than the USGS DEM, but unfortunately derives topography at the top of the canopy, which is up to 26 m above the floor of the

  20. Physical and chemical characteristics of Terrace Reservoir, Conejos County, Colorado, May 1994 through May 1995 (United States)

    Stogner, Sr., Robert W.; Edelmann, Patrick; Walton-Day, Katherine


    Terrace Reservoir receives drainage of low-pH, metal-enriched water from mineralized areas, including the Summitville Mine, within the AlamosaRiver Basin. Drainage from the Summitville Mine has contributed a substantial part of the metal load to Terrace Reservoir. From May 1994 through May 1995, a study was done by the U.S. Geological Survey, in cooperation with the U.S. Environmental Protection Agency, to evaluate the physical and chemical characteristics of Terrace Reservoir.Terrace Reservoir was thermally stratified from about mid-May through August 1994. Thermal stratification was absent from September\\x111994through March 1995. During periods of stratification, underflow of the Alamosa River was predominant, and residence times of the underflow were shortened by 40 to 75\\x11percent of the theoretical residence times for a well-mixed reservoir. Transport and deposition of suspended solids in Terrace Reservoir varied spatially and temporally. Most of the suspended solids were deposited in Terrace Reservoir. The concentration of dissolved oxygen in the reservoir varied little spatially or temporally and generally was within a few tenths of the dissolved-oxygen concentration of the inflow. The pH of water in the reservoir generally ranged from about 4.0 to about 7.0, depending on date, depth, and location. The largest pH values were measured during May. A markeddecrease of about 1.5\\x11pH units occurred at site T5 in the reservoir about mid-June. The pH of the reservoir remained at or below 5.5 from mid-June through November. Dissolved-metal concentrations varied spatially and temporally in response to several factors, which included inflow characteristics, reservoir stratification and mixing, inflow-routing and flow-through patterns, residence times, sedimentation, dissolved oxygen, and pH.Inflow chemistry is the dominant controlling factor of metal chemistry within Terrace Reservoir.During periods of stratification, large vertical variations in metal

  1. Comparing OSL and CN techniques for dating fluvial terraces and estimating surface process rates in Pamir (United States)

    Fuchs, Margret; Gloaguen, Richard; Pohl, Eric; Sulaymonova, Vasila; Merchel, Silke; Rugel, Georg


    The quantification of surface process rates is crucial for understanding the topographic evolution of high mountains. Spatial and temporal variations in fluvial incision and basin-wide erosion enable to decipher the role of tectonic and climatic drivers. The Pamir is peculiar in both aspects because of its location at the western end of the India-Asia collision zone, and its position at the edge of two atmospheric circulation systems, the Westerlies and the Indian Summer Monsoon. The architecture of the Panj river network indicates prominent variations across the main tectonic structures of the Pamir. The trunk stream, deflects from the predominantly westward river orientation and cuts across the southern and central Pamir domes before doubling back to the west and leaving the orogen. Optically stimulated luminescence (OSL) dating of fluvial terraces reveals short-term sedimentation along the trunk stream during the last ~25 kyr. The agreement of OSL results to new exposure ages based on the cosmogenic nuclide (CN) 10Be confirms accurate terrace age modelling and treatment of incomplete bleaching. The consistent terrace sedimentation and exposure ages suggest also fast terrace abandonment and rapid onset of incision. Considerable differences in terrace heights reflect high spatial variations of fluvial incision, independent of time interval, change in rock type or catchment increase. Highest rates of (5.9 ± 1.1) mm/yr to (10.0 ± 2.0) mm/yr describe the fluvial dynamic across the Shakhdara Dome and that related to the Darvaz Fault Zone. Lower rates of (3.9 ± 0.6) mm/yr to (4.5 ± 0.7) mm/yr indicate a transient stage north of the Yazgulom Dome. Fluvial incision decreases to rates ranging from (1.7 ± 0.3) mm/yr to (3.9 ± 0.7) mm/yr in graded river reaches associated to southern dome boundaries. The pattern agrees to the interpretation of successive upstream river captures across the southern and central Pamir domes inferred from morphometric analyses of river

  2. Late Quaternary mass-wasting records and formation of alluvial terraces in the actively uplifting Lao-nong catchment, southwestern Taiwan (United States)

    Tsui, H. K.; Hsieh, M. L.; Li, W. L.; Hsiao, Y. T.


    Although dominated by erosion over long term, the tectonically active mountains of Taiwan commonly contain thick landslide and debris-flow gravels capping hillslopes or forming alluvial terraces. These deposits and their associated landforms serve to study ancient mass-wasting histories and their controls on fluvial processes. This study focuses on the Lao-nong River draining the 1000-3000 m high mountain areas in southwestern Taiwan (current tectonic uplift: 10-20 mm/yr). The Lao-nong River exhibits numerous terraces, many of which are of tributary-fan origins and consist of fluvial/debris-flow gravels 20-200 m thick. The development of such alluvial terraces can be observed during 2009 Typhoon Morakot, which brought record-setting 2000 mm of rain. Triggered by this heavy rain, almost all the tributaries of the Lao-nong generated alluvial fans at their mouths and consequently caused up-to-30 m aggradation along the trunk river. The Lao-nong has yielded >100 radiocarbon dates (all internal factors on the timing, magnitude, and frequency of the events. Our field observation suggests that at least some of the large Holocene tributary-fan terraces were sourced from pre-Holocene colluviums.

  3. Quantification of fluvial response to tectonic deformation in the Central Pontides, Turkey; inferences from OSL dating of fluvial terraces (United States)

    McClain, Kevin; Yıldırım, Cengiz; Çiner, Attila; Akif Sarıkaya, M.; Şahin, Sefa; Özcan, Orkan; Güneç Kıyak, Nafiye; Öztürk, Tuǧba


    From Late Miocene to present, Anatolia's rapid counterclockwise movement, which increases in velocity towards the Hellenic Arc, has formed the North Anatolian Fault (NAF), a dextral transform fault along the Anatolia-Eurasia plate boundary and the northern margin of the Central Anatolian Plateau (CAP). A zone of transpression referred to as the Central Pontides exists between the broad restraining bend of the NAF and the Black Sea Basin, uplifting what is interpreted as a detached flower structure. Dating of Quaternary landforms in the eastern flank of the Central Pontides has helped to understand its recent deformation. However, in the western flank of the Central Pontides there is an absence of Quaternary studies, relatively quiet modern seismicity, and difficulties locating or observing fault scarps. This led us to use optically stimulated luminescence dating (OSL-dating) of fluvial terrace sediments and the study of geomorphic features to gain insight into the influence of climate and tectonics on landscape evolution of this area. In this area, the Filyos River crosses the Karabük Fault (reverse fault) and deeply incises a gorge through the Karabük Range before flowing towards the Black Sea. In the gorge an abundance of indicators of tectonic deformation were mapped, such as hanging valleys, wind gaps, bedrock gorges, landslides, steep V-shaped channels, tilted basins, as well as fluvial strath terraces. In particular, strath terraces of at least 8 levels within just 1.5 km of horizontal distance were examined. We used OSL-dating to estimate five deposition ages of fluvial strath terrace sediments, leading to an estimation of incision and uplift rates over time. Using three samples per terrace with strath elevations of 246 ± 0.2 m, 105.49 ± 0.2 m, 43.6 ± 0.2 m, 15.3 ± 0.2 m and 3.6 ± 0.2 m above the Filyos River, we determined corresponding ages of 841 ± 76 ka, 681 ± 49 ka, 386 ± 18 ka, 88 ± 5.1 ka and 50.9 ± 2.8 ka. Incision rates over time (oldest

  4. Post-eruptive Submarine Terrace Development of Capelinhos, Azores (United States)

    Zhongwei Zhao, Will; Mitchell, Neil; Quartau, Rui; Tempera, Fernando; Bricheno, Lucy


    Erosion of the coasts of volcanic islands by waves creates shallow banks, but how erosion proceeds with time to create them and how it relates to wave climate is unclear. In this study, historical and recent marine geophysical data collected around the Capelinhos promontory (western Faial Island, Azores) offer an unusual opportunity to characterize how a submarine terrace developed after the eruption. The promontory was formed in 1957/58 during a Surtseyan eruption that terminated with extensive lava forming new rocky coastal cliffs. Historical measurements of coastline position are supplemented here with coastlines measured from 2004 and 2014 Google Earth images in order to characterize coastline retreat rate and distance for lava- and tephra-dominated cliffs. Swath mapping sonars were used to characterize the submarine geometry of the resulting terrace (terrace edge position, gradient and morphology). Limited photographs are available from a SCUBA dive and drop-down camera deployments to ground truth the submarine geomorphology. The results reveal that coastal retreat rates have decreased rapidly with the time after the eruption, possibly explained by the evolving resistance to erosion of cliff base materials. Surprisingly, coastline retreat rate decreases with terrace width in a simple inverse power law with terrace width. We suspect this is only a fortuitous result as wave attenuation over the terrace will not obviously produce the variation, but nevertheless it shows how rapidly the retreat rate declines. Understanding the relationship between terrace widening shelf and coastal cliff retreat rate may be more widely interesting if they can be used to understand how islands evolve over time into abrasional banks and guyots.

  5. Valley evolution by meandering rivers (United States)

    Limaye, Ajay Brian Sanjay

    Fluvial systems form landscapes and sedimentary deposits with a rich hierarchy of structures that extend from grain- to valley scale. Large-scale pattern formation in fluvial systems is commonly attributed to forcing by external factors, including climate change, tectonic uplift, and sea-level change. Yet over geologic timescales, rivers may also develop large-scale erosional and depositional patterns that do not bear on environmental history. This dissertation uses a combination of numerical modeling and topographic analysis to identify and quantify patterns in river valleys that form as a consequence of river meandering alone, under constant external forcing. Chapter 2 identifies a numerical artifact in existing, grid-based models that represent the co-evolution of river channel migration and bank strength over geologic timescales. A new, vector-based technique for bank-material tracking is shown to improve predictions for the evolution of meander belts, floodplains, sedimentary deposits formed by aggrading channels, and bedrock river valleys, particularly when spatial contrasts in bank strength are strong. Chapters 3 and 4 apply this numerical technique to establishing valley topography formed by a vertically incising, meandering river subject to constant external forcing---which should serve as the null hypothesis for valley evolution. In Chapter 3, this scenario is shown to explain a variety of common bedrock river valley types and smaller-scale features within them---including entrenched channels, long-wavelength, arcuate scars in valley walls, and bedrock-cored river terraces. Chapter 4 describes the age and geometric statistics of river terraces formed by meandering with constant external forcing, and compares them to terraces in natural river valleys. The frequency of intrinsic terrace formation by meandering is shown to reflect a characteristic relief-generation timescale, and terrace length is identified as a key criterion for distinguishing these

  6. Late Holocene marine terraces of the Cartagena region, southern Caribbean: The product of neotectonism or a former high stand in sea-level? (United States)

    Ignacio Martínez, J.; Yokoyama, Yusuke; Gomez, Andres; Delgado, Adriana; Matsuzaki, Hiroyuki; Rendon, Esteban


    The detailed stratigraphic survey and paleontological study (mollusks, corals, foraminifera and ostracods) of four low-level, ˜3 m, marine terrace sections: Punta Canoas, Manzanillo del Mar, Playa de Oro, and Tierra Bomba Island, from the Cartagena region, southern Caribbean, supplemented with 22 radiocarbon dates, reveals that the northern terraces were deposited as parasequences in a clastic depositional system compared to the Tierra Bomba Island succession that was deposited in a carbonate depositional system between ˜3600 and ˜1700 cal yrs BP. Drier conditions and the southern location of the ITCZ at about 3 ka triggered stronger easterly Trades and more dynamic southwestward sediment drift fed by the Magdalena River mouth, thus promoting the formation of sand spits that ultimately isolated the Cienaga de Tesca coastal lagoon from the Caribbean Sea. Our estimates support the hypothesis that the present position of the terraces is the product of neotectonism rather than a higher 3 ka, sea-level. Upheaval of the terraces varies between ˜3.8 mmyr -1 at Punta Canoas and ˜2.2 mmyr -1 at Tierra Bomba to ˜1.5 mmyr -1 at Manzanillo del Mar and Playa de Oro terraces. Our study corroborates previous contentions on the role of mud diapirism and the dynamics of the Dique Fault as late Holocene upheaval mechanisms.

  7. Quaternary Deformation of Sumba, Indonesia: Evidence from Carbonate Terraces (United States)

    Dahlquist, M. P.; West, A. J.; Dolan, J. F.


    The Banda Arc of Indonesia remains one of the least understood tectonic domains on the modern Earth. The island of Sumba, located approximately 50 km south of Flores and 120 km north of the Java Trench, northwest of where it transitions into the Timor Trough, lies in a region of tectonic transition and potentially offers insights into regional dynamics. The Banda Arc is volcanically active, but Sumba itself is not volcanic. The northern coast of Sumba is covered in Quaternary coral terraces, with the rest of the island's surface geology composed of Mio-pliocene carbonates and uplifted Late Cretaceous-Oligocene forearc basin and volcanic rocks. The purpose of this study is to remotely map the topographic expression of the coral terraces and use the information gained to better understand deformation on Sumba since their deposition. The ages of the coral terraces, of which many platforms are exposed over significant areas of the island, have been constrained at Cape Luandi in north central Sumba, but uplift rates calculated from those ages may not be representative of the island as a whole. The lateral continuity of these dated terraces can help constrain the extent to which uplift of Sumba is spatially variable. Analysis of the terraces using SRTM digital elevation data with ArcGIS software makes it possible to trace the same terrace platforms over large distances, and shows that the north central part of the island has experienced the most uplift since the deposition of the terraces, forming an anticline with the east limb dipping more steeply than the west. The terraces are not well preserved on the southern half of the island. Exposure of older rocks and lack of terrace preservation, as well as a south-skewed drainage divide suggests the southern half of the island experiences greater exhumation, but this could be driven by climate or other factors and does not necessarily indicate more rapid uplift. Study of Quaternary deformation of Sumba can offer greater

  8. TerraceM: A Matlab® tool to analyze marine terraces from high-resolution topography (United States)

    Jara-Muñoz, Julius; Melnick, Daniel; Strecker, Manfred


    To date, Light detection and ranging (LiDAR), high- resolution topographic data sets enable remote identification of submeter-scale geomorphic features bringing valuable information of the landscape and geomorphic markers of tectonic deformation such as fault-scarp offsets, fluvial and marine terraces. Recent studies of marine terraces using LiDAR data have demonstrated that these landforms can be readily isolated from other landforms in the landscape, using slope and roughness parameters that allow for unambiguously mapping regional extents of terrace sequences. Marine terrace elevation has been used since decades as geodetic benchmarks of Quaternary deformation. Uplift rates may be estimated by locating the shoreline angle, a geomorphic feature correlated with the high-stand position of past sea levels. Indeed, precise identification of the shoreline-angle position is an important requirement to obtain reliable tectonic rates and coherent spatial correlation. To improve our ability to rapidly assess and map different shoreline angles at a regional scale we have developed the TerraceM application. TerraceM is a Matlab® tool that allows estimating the shoreline angle and its associated error using high-resolution topography. For convenience, TerraceM includes a graphical user interface (GUI) linked with Google Maps® API. The analysis starts by defining swath profiles from a shapefile created on a GIS platform orientated orthogonally to the terrace riser. TerraceM functions are included to extract and analyze the swath profiles. Two types of coastal landscapes may be analyzed using different methodologies: staircase sequences of multiple terraces and rough, rocky coasts. The former are measured by outlining the paleo-cliffs and paleo-platforms, whereas the latter are assessed by picking the elevation of sea-stack tops. By calculating the intersection between first-order interpolations of the maximum topography of swath profiles we define the shoreline angle in

  9. Applying an agent-based model of agricultural terraces coupled with a landscape evolution model to explore the impact of human decision-making on terraced terrain (United States)

    Glaubius, Jennifer


    Agricultural terraces impact landscape evolution as a result of long-term human-landscape interactions, including decisions regarding terrace maintenance and abandonment. Modeling simulations are often employed to examine the sensitivity of landscapes to various factors, such as rainfall and land cover. Landscape evolution models, erosion models, and hydrological models have all previously been used to simulate the impact of agricultural terrace construction on terrain evolution, soil erosion, and hydrological connectivity. Human choices regarding individual terraces have not been included in these models to this point, despite recent recognition that maintenance and abandonment decisions alter transport and storage patterns of soil and water in terraced terrain. An agent-based model of human decisions related to agricultural terraces is implemented based on a conceptual model of agricultural terrace life cycle stages created from a literature review of terracing impacts. The agricultural terracing agent-based model is then coupled with a landscape evolution model to explore the role of human decisions in the evolution of terraced landscapes. To fully explore this type of co-evolved landscape, human decision-making and its feedbacks must be included in landscape evolution models. Project results may also have implications for management of terraced terrain based on how human choices in these environments affect soil loss and land degradation.

  10. Capturing sediment and nutrients in irrigated terraced landscapes (United States)

    Slaets, Johanna; Schmitter, Petra; Hilger, Thomas; Piepho, Hans-Peter; Dercon, Gerd; Cadisch, Georg


    Terraces are often promoted as green filters in landscapes, buffering discharge and constituent peaks. For irrigated rice terraces, however, this mitigating potential has not been assessed at the landscape level. Additionally, sediment and nutrient inputs potentially affect soil fertility in agricultural terraces and therefore yield - the extent of the impact depending on the quality and quantity of the captured material. Quantifying such upland-lowland linkages is particularly important in intensely cultivated landscapes, as declining upland soil fertility could alter beneficial hydrological connectivity between terraces and surrounding landscapes. In this study, we therefore quantified the sediment, sediment-associated organic carbon and nitrogen inputs and losses for a 13 ha paddy rice area, surrounded by upland maize cultivation in Northwest Vietnam in 2010 and 2011. Turbidity sensors were used in combination with a linear mixed model in order to obtain continuous predictions of the constituent concentrations. Sediment texture was determined using mid-infrared spectroscopy. Uncertainty on annual load estimates was quantified by calculating 95% confidence intervals with a bootstrap approach. Sediment inputs from irrigation water to the rice area amounted to 48 Mg ha-1 a-1 and runoff during rainfall events contributed an additional 16 Mg ha-1 a-1. Export from the rice terraces equalled 63 Mg ha-1 a-1 of sediments, resulting in a net balance of 28 Mg ha-1 a-1 or a trapping of almost half of the annual sediment inputs. Runoff contributed one third of the sand inputs, while irrigated sediments were predominantly silty. As paddy outflow contained almost exclusively silt- and clay-sized material, 24 Mg ha-1 a-1 of captured sediments consisted of sand. The sediment-associated organic carbon resulted in a deposit of 1.09 Mg ha-1 a-1. For sediment-associated nitrogen, 0.68 Mg ha-1 a-1 was trapped in the terraces. Combining both sediment-associated and dissolved nitrogen

  11. The physical model of a terraced plot: first results (United States)

    Perlotto, Chiara; D'Agostino, Vincenzo; Buzzanca, Giacomo


    Terrace building have been expanded in the 19th century because of the increased demographic pressure and the need to crop additional areas at steeper slopes. Terraces are also important to regulate the hydrological behavior of the hillslope. Few studies are available in literature on rainfall-runoff processes and flood risk mitigation in terraced areas. Bench terraces, reducing the terrain slope and the length of the overland flow, quantitatively control the runoff flow velocity, facilitating the drainage and thus leading to a reduction of soil erosion. The study of the hydrologic-hydraulic function of terraced slopes is essential in order to evaluate their possible use to cooperate for flood-risk mitigation also preserving the landscape value. This research aims to better focus the times of the hydrological response, which are determined by a hillslope plot bounded by a dry-stone wall, considering both the overland flow and the groundwater. A physical model, characterized by a quasi-real scale, has been built to reproduce the behavior of a 3% outward sloped terrace at bare soil condition. The model consists of a steel metal box (1 m large, 3.3 m long, 2 m high) containing the hillslope terrain. The terrain is equipped with two piezometers, 9 TDR sensors measuring the volumetric water content, a surface spillway at the head releasing the steady discharge under test, a scale at the wall base to measure the outflowing discharge. The experiments deal with different initial moisture condition (non-saturated and saturated), and discharges of 19.5, 12.0 and 5.0 l/min. Each experiment has been replicated, conducting a total number of 12 tests. The volumetric water content analysis produced by the 9 TDR sensors was able to provide a quite satisfactory representation of the soil moisture during the runs. Then, different lag times at the outlet since the inflow initiation were measured both for runoff and groundwater. Moreover, the time of depletion and the piezometer

  12. Ecosystem services provided by agricultural terraces in semi-arid climates. (United States)

    Romero-Díaz, Asunción; Díaz-Pereira, Elvira; Boix-Fayos, Carolina; de Vente, Joris


    Since ancient times, agricultural terraces are common features throughout the world, especially on steep slope gradients. Nowadays many terraces have been abandoned or removed and few new terraces are build due to increased mechanisation and intensification of agriculture. However, terraces are amongst the most effective soil conservation practices, reducing the slope gradient and slope length, as well as runoff rate and soil erosion, and without terraces, it would be impossible to cultivate on many hillslopes. Moreover, their scenic interest is undeniable, as in some cases, terraced slopes have even become part of UNESCO World Heritage. In order to highlight the potential benefits, requirements and limitations of terraces, we reviewed different types of sustainable land management practices related to terraces and characterised their implications for provisioning, regulating, supporting, and cultural ecosystem services. We centred our review on terraces in semi-arid environments worldwide, as were documented in the WOCAT (World Overview of Conservation Approaches and Technologies) database. Our results show that the most important ecosystem services provided by terraces relate to regulation of the on-site and off-site effects of runoff and erosion, and maintenance of soil fertility and vegetation cover. The presence of terraces also favours the provision of food, fiber, and clean water. In short, our results stress the crucial environmental, geomorphological and hydrological functions of terraces that directly relate to improving the quality of life of the people that use them. These results highlight the need for renewed recognition of the value of terraces for society, their preservation and maintenance.

  13. Digital data sets that describe aquifer characteristics of the Enid isolated terrace aquifer in northwestern Oklahoma (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized aquifer boundaries for the Enid isolated terrace aquifer in northwestern Oklahoma. The Enid isolated terrace aquifer covers...

  14. Digital data sets that describe aquifer characteristics of the Enid isolated terrace aquifer in northwestern Oklahoma (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of a digitized polygon of a constant recharge value for the Enid isolated terrace aquifer in northwestern Oklahoma. The Enid isolated terrace...

  15. Digital data sets that describe aquifer characteristics of the Enid isolated terrace aquifer in northwestern Oklahoma (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized water-level elevation contours for the Enid isolated terrace aquifer in northwestern Oklahoma. The Enid isolated terrace aquifer...

  16. Monitoring and modelling for dry-stone walls terracement maintenance (United States)

    Preti, Federico; Errico, Alessandro; Giambastiani, Yamuna; Guastini, Enrico; Penna, Daniele


    An analysis of dry-stone walls stability in agricultural areas based on innovative monitoring and modeling is here presented The field test took place in Lamole, a terraced rural area located in the province of Florence, Tuscany, central Italy, where wine production is the most important agricultural activity business. Results show a good capability of the model to predict the time-space distribution and the intensity of stresses on the instrumented dry-stone wall and to describe the bulging of the ancient ones. We obtained significant information on how the terrace failure in Lamole resulted mainly related to the water concentration pathways at specific portions of the walls. An accurate drainage of the terraced slopes, even by means of simple ditches, could reduce the concentration factor at the critical parts of terraces strongly reducing the water pressures on the walls. The analysis of the effects caused by high return time events has been carried out by means of artificially reproduced severe rainfalls on the presented experimental area.

  17. Porosity prediction from seismic inversion, Lavrans Field, Halten Terrace

    Energy Technology Data Exchange (ETDEWEB)

    Dolberg, David M.


    This presentation relates to porosity prediction from seismic inversion. The porosity prediction concerns the Lavrans Field of the Halten Terrace on the Norwegian continental shelf. The main themes discussed here cover seismic inversion, rock physics, statistical analysis - verification of well trends, upscaling/sculpting, and implementation. 2 refs., 6 figs.

  18. Modeling right-lateral offset of a Late Pleistocene terrace riser along the Polaris fault using ground based LiDAR imagery (United States)

    Howle, J. F.; Bawden, G. W.; Hunter, L. E.; Rose, R. S.


    High resolution (centimeter level) three-dimensional point-cloud imagery of offset glacial outwash deposits were collected by using ground based tripod LiDAR (T-LiDAR) to characterize the cumulative fault slip across the recently identified Polaris fault (Hunter et al., 2009) near Truckee, California. The type-section site for the Polaris fault is located 6.5 km east of Truckee where progressive right-lateral displacement of middle to late Pleistocene deposits is evident. Glacial outwash deposits, aggraded during the Tioga glaciation, form a flat lying ‘fill’ terrace on both the north and south sides of the modern Truckee River. During the Tioga deglaciation melt water incised into the terrace producing fluvial scarps or terrace risers (Birkeland, 1964). Subsequently, the terrace risers on both banks have been right-laterally offset by the Polaris fault. By using T-LiDAR on an elevated tripod (4.25 m high), we collected 3D high-resolution (thousands of points per square meter; ± 4 mm) point-cloud imagery of the offset terrace risers. Vegetation was removed from the data using commercial software, and large protruding boulders were manually deleted to generate a bare-earth point-cloud dataset with an average data density of over 240 points per square meter. From the bare-earth point cloud we mathematically reconstructed a pristine terrace/scarp morphology on both sides of the fault, defined coupled sets of piercing points, and extracted a corresponding displacement vector. First, the Polaris fault was approximated as a vertical plane that bisects the offset terrace risers, as well as bisecting linear swales and tectonic depressions in the outwash terrace. Then, piercing points to the vertical fault plane were constructed from the geometry of the geomorphic elements on either side of the fault. On each side of the fault, the best-fit modeled outwash plane is projected laterally and the best-fit modeled terrace riser projected upward to a virtual intersection in

  19. Effects of terracing on soil and water conservation in China: A meta-analysis (United States)

    Chen, Die; Wei, Wei


    Terracing has long been considered a powerful strategy for soil and water conservation. However, the efficiency is limited by many factors, such as climate, soil properties, topography, land use, population and socioeconomic status. The aim of this critical review was to discuss the effects of terracing on soil and water conservation in China, using a systematic approach to select peer-reviewed articles published in English and Chinese. 46 individual studies were analyzed, involving six terracing structures (level terraces, slope-separated terraces, slope terraces, reverse-slope terraces, fanya juu terraces and half-moon terraces), a wide geographical range (Northeastern China, Southeastern hilly areas, Southwestern mountain areas and Northwestern-central China), and six land use types (forest, crop trees, cropland, shrub land, grassland and bare land) as well as a series of slope gradients ranging from 3° to 35°. Statistical meta-analysis with runoff for 593 observations and sediment for 636 observations confirmed that terracing had a significant effect on water erosion control. In terms of different terrace structures, runoff and sediment reduction were uppermost on slope-separated terraces. Land use in terraces also played a crucial role in the efficiency of conservation, and tree crops and forest were detected as the most powerful land covers in soil and water conservation due to large aboveground biomass and strong root systems below the ground, which directly reduces the pressure of terraces on rainwater redistribution. In addition, a significant positive correlation between slope gradients (3° 15° and 16° 35°) and terracing efficiency on soil and water conservation was observed. This study revealed the effectiveness and variation of terracing on water erosion control on the national scale, which can serve as a scientific basis to land managers and decision-makers.

  20. Agricultural terraces and slope instability at Cinque Terre (NW Italy) (United States)

    Brandolini, Pierluigi; Cevasco, Andrea


    Cinque Terre, located in the eastern Liguria, are one of the most representative examples of terraced coastal landscape within the Mediterranean region. They are the result of a century-old agricultural practice and constitute an outstanding example of human integration with the natural landscape. For this highly unusual man-made coastal landscape, the Cinque Terre have been recognized as a World Heritage Site by UNESCO since 1997 and became National Park in 1999. The complex network of retaining dry stone walls and drainage networks ensured through times the control of shallow water erosion and therefore, indirectly, favoured debris cover stability. The lack of maintenance of terracing due to farmer abandonment since the 1950s led to widespread slope erosion phenomena. The effects of such phenomena culminated during the 25 October 2011 storm rainfall event, when slope debris materials charged by streams gave rise to debris floods affecting both Monterosso and Vernazza villages. As the analysis of the relationships between geo-hydrological processes and land use in the Vernazza catchment highlighted, abandoned and not well maintained terraces were the most susceptible areas to shallow landsliding and erosion triggered by intense rainfall. As a consequence, the thousands of kilometres of dry stone walls retaining millions of cubic metres of debris cover at Cinque Terre currently constitute a potential menace for both villages, that are mainly located at the floor of deep cut valleys, and tourists. Given the increasing human pressure due to tourist activities, geo-hydrological risk mitigation measures are urgently needed. At the same time, restoration policies are necessary to preserve this extraordinary example of terraced coastal landscape. In this framework, the detailed knowledge of the response of terraced areas to intense rainfall in terms of slope instability is a topic issue in order to identify adequate land planning strategies as well as the areas where

  1. 黄土高原水平梯田现状及减沙作用分析%The Status and Sediment Reduction Effects of Level Terrace in the Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    马红斌; 李晶晶; 何兴照; 刘晓燕; 王富贵


    Level terrace is one of the most important measures of developing soil and water conservation and efficient agriculture in the Loess Plateau,which has the dual role of agriculture efficiency and ecological restoration. This paper analyzed the level terrace status:including scale,distribution,quality,planting structure and sediment reduction effects,based on remote sensing image of the ZY-3 Satellite and field survey. The results show that there have level terrace 3. 71 million hm2 by the end of 2012,mainly distributed in the Yellow River basin in Gansu Province and adjacent areas and Hekouzhen-Longmen reaches of the Yellow River in Shanxi Province,where the terraced area ac-counts for around 54. 3% of the total terrace area in the Loess Plateau;Level terrace in Weihe River,Jinghe River and Zulihe River has a high quality rank and is dominated by farming,however,there have mainly narrow terraces with width 4-6 m in He-Long reaches,and"Terrace for Farmland" is commonly appearing. In the future,terrace construction in the Yellow River of Gansu Province should give priority to damaged terrace reconstruction,the development space maybe 5% ~15%,however,He-Long reaches has a higher development poten-tial,expect to increase new terrace by as much as 25%. Based on the terrace sediment reduction calculation method,the existing level ter-races in the area upstream Tongguan can reduce sediment about 500 million tons.%水平梯田是黄土高原地区发展水土保持高效农业的重要措施之一,具有农业增效、生态修复的双重功能。基于资源三号卫星遥感影像和实地调查数据,分析了2012年黄土高原地区梯田现状:规模、分布、质量、利用方式及其减沙作用。结果表明:截至2012年底,黄土高原地区现有水平梯田371.29万hm2,主要分布在甘肃省黄河流域及其邻近地区、山西省河龙间支流流域,这些区域水平梯田面积占黄土高原梯田总面积的54.3%;渭河、

  2. Evaluation of the denitrification rate of terraced paddy fields (United States)

    Onishi, Takeo; Nakamura, Kimihito; Horino, Haruhiko; Adachi, Toru; Mitsuno, Toru


    SummaryRice is one of the most important staple foods in the world. Lowland paddy fields are well known for functioning as denitrification areas, but few studies have been conducted of paddy fields situated on hill slopes (terraced paddy fields). These terraced paddy fields have a characteristic artificial stepped shape, and this unique shape and periodic ponding from rice production may configure unique hydrological properties that might be different from lowland paddy fields. The shape and hydrological properties may also affect transport of nutrients such as nitrogen. This study is particularly focused on the denitrification rate in terraced paddy fields. To understand the hydrological properties of terraced paddy fields, a detailed water budget including the subsurface flow components was calculated. Combining the water budget components and chemical measurements of surface and subsurface water, a nitrogen budget was calculated. The results showed that about 10% of the total nitrogen input, mainly from fertilizers, was lost, suggesting the occurrence of denitrification in the area. The average denitrification rate of the study site was estimated at about 0.53-0.67 g N m-2 year-1. Spatial variations in the measured groundwater nitrate concentration suggest that denitrification is important in both the plough layer and the sloping area. The denitrification rate in the sloping area was estimated at 0.67-0.78 g N m-2 year-1, which is slightly higher than the estimates of denitrification rate in paddy lots, i.e., 0.56-0.61 g N m-2 year-1. The result indicates the importance of sloping areas for denitrification in terraced paddy fields.

  3. Development and application of algorithms for simulating terraces practices within SWAT (United States)

    Terraces have been proven to be an effective conservation practice for controlling high soil loss. In large hydrological programs such as Soil and Water Assessment Tool (SWAT), terrace effects are simulated by adjusting the slope length and the USLE P-factor. In this study, a process-based terrace a...

  4. Post-tectonic landscape evolution in NE Iberia using staircase terraces: Combined effects of uplift and climate (United States)

    Lewis, Claudia J.; Sancho, Carlos; McDonald, Eric V.; Peña-Monné, José Luis; Pueyo, Emilio L.; Rhodes, Edward; Calle, Mikel; Soto, Ruth


    River incision into bedrock resulting from the combined effects of tectonic uplift and climate governs long-term regional landscape evolution. We determined spatial and temporal patterns of post-orogenic stream incision from a sequence of well-preserved staircase terraces developed over the last 1 Ma in the Central Pyrenees and its southern foreland Ebro basin (NE Spain). Extensive remnants of ten vertically separated terraces (Qt1 to Qt10, from oldest to youngest) were mapped along 170 km of the Cinca River valley, transverse to the Pyrenean mountain belt. Multiple outcrops appear in the upper reach of the valley (Ainsa sector, 50 km from headwaters) as well as in the lower reach (Albalate sector, 125 km from headwaters). Fluvial incision into bedrock was calculated using (i) differentially corrected GPS measurements of the altitude of straths and (ii) numerical dating of alluvial sediments from the lower terraces (Qt5 to Qt9) by Optically Stimulated Luminescence, previously reported by Lewis et al. (2009), and supplemented with new dates for the upper terraces (Qt1, Qt2 and Qt3) based on paleomagnetism and supported by soil development. Considering altitude differences and the elapsed time between successive well preserved terrace couples (Qt3-Qt7, Qt7-Qt9 and Qt9-Active channel), mean bedrock incision rates ranged from 0.76 to 0.38 m ka- 1, at the upper reach of the valley (Ainsa section), and from 0.61 to 0.20 m ka- 1, at the lower reach (Albalate section). River incision along the valley produced vertically separated, near-parallel longitudinal terrace profiles evidencing a rapid near-uniform regional uplift as response to (i) the tectonic lithospheric thickening in NE Iberia and (ii) the erosional download rebound related to the Ebro basin exorheism. Moreover, a subtle upstream divergence of strath profiles may have been a consequence of an increase in uplift rate toward the head of the valley. Additionally, incision rates changed over time as indicate

  5. River

    Directory of Open Access Journals (Sweden)

    Morel Mathieu


    Full Text Available The OECD report “Boosting Resilience through Innovative Risk Governance” examines the efforts of OECD countries to prevent or reduce future disaster impacts, and highlights several key areas where improvements can be made. International collaboration is insufficiently utilised to address shocks that have increasingly global consequences. Institutional design plays a significant role in facilitating or hampering the engagement and investments of governmental and non-governmental stakeholders in disaster risk prevention and mitigation. To inform the design of “better” institutions, the OECD proposes the application of a diagnostic framework that helps governments identify institutional shortcomings and take actions to improve them. The goal of the case study on the Rhone River is to conduct an analysis of the progress, achievements and existing challenges in designing and implementing disaster risk reduction strategies through the Rhone Plan from a comparative perspective across a set of selected countries of this study, like Austria and Switzerland, will inform how to improve institutional frameworks governing risk prevention and mitigation. The case study will be used to identify examples of successful practice taking into account their specific country contexts, and analyse their potential for policy transfer.

  6. Late Pleistocene-Holocene uplift driven terrace formation and climate-tectonic interplay from a seismically active intraplate setting: An example from Kachchh, Western India (United States)

    Prizomwala, S. P.; Das, Archana; Chauhan, G.; Solanki, T.; Basavaiah, N.; Bhatt, Nilesh; Thakkar, M. G.; Rastogi, B. K.


    Fluvial terrace formation is often regulated by external forcings like climate, tectonic and eustatic changes. These terraces, particularly in a dryland environment, preserves the discrete signatures of these external forcings, thus enabling us to reconstruct the fluvial response to the late Quaternary palaeoenvironmental changes and factors governing them. The present study focuses on reconstructing the aggradation/incision phases in the Lotia River which is located in the eastern segment of the Northern Hill Range (NHR) of the Kachchh Peninsula. The Lotia river drains through Mesozoic rocks before cutting across the Kachchh Mainland Fault (KMF) and finally debouch in the Banni Plains. Reconstruction based on tectonic geomorphology, sedimentology, sediment geochemistry, mineral magnetic, and OSL chronology suggests the fluvial response to monsoon variability archived during the last 15 ka. The time frame was also marked by incision enhanced by uplift along the KMF, which led to strath terrace formation. The accommodation space thus created was filled by an aggradational event between 14.8 ka and 10.6 ka. Sedimentological and geochemical parameters have also suggested that the time period between 12.5 ka and 11.5 ka showed a decline in the monsoon strength, which coincides with 'Younger Dryas'. It has been observed that the sediments spanning between 10.6 ka and 7.8 ka are absent from the archive, which is most likely the manifestation of the early Holocene optimum that led to severe erosional processes. The period between 7.8 ka and 3.3 ka is marked as another aggradational phase with fluctuating climatic conditions. At 3.3 ka, the region has experienced an incision of 4 m, which led to the formation of Holocene terrace T1, most likely due to tectonic uplift. During the last 3.3 ka, another pulsative uplift has occurred, which led to the formation of unpaired Holocene terrace T2, along with tilting of the Lotia basin. Based on the OSL chronology of bedrock strath

  7. Twenty lectures on thermodynamics

    CERN Document Server

    Buchdahl, H A


    Twenty Lectures on Thermodynamics is a course of lectures, parts of which the author has given various times over the last few years. The book gives the readers a bird's eye view of phenomenological and statistical thermodynamics. The book covers many areas in thermodynamics such as states and transition; adiabatic isolation; irreversibility; the first, second, third and Zeroth laws of thermodynamics; entropy and entropy law; the idea of the application of thermodynamics; pseudo-states; the quantum-static al canonical and grand canonical ensembles; and semi-classical gaseous systems. The text

  8. Assessment of metal transport into and out of Terrace Reservoir, Conejos County, Colorado, April 1994 through March 1995; interim report (United States)

    Ferguson, Sheryl; Edelmann, Patrick


    Terrace Reservoir is the primary source of water for crops and livestock in the southwestern part of the San Luis Valley in southern Colorado. Mining activities have occurred in the basin for more than 100 years, and substantial mining of gold has occurred intermittently at the Summitville Mine.Historically, the Summitville Mine site has produced highly acidic, metal-enriched water that drained from the mine site into Wightman Fork and flowed to the Alamosa River and Terrace Reservoir. In 1994, a study was begun as part of risk-assessment and remediation efforts and to evaluate metal transport into and out of Terrace Reservoir. During the study period, the pH immediately upstream from Terrace Reservoir ranged from 4.3 to 7.8. The highest pH occurred during the pre-peak snowmelt period; the lowest pH occurred during storm runoff during summer. Downstream from Terrace Reservoir, the pH ranged from 4.6 to 7.6. The highest pH occurred during the pre-peak snowmelt period, and the lowest pH occurred during summer in mid-July. A comparison of the streamflow hydrographs upstream and downstream from Terrace Reservoir indicated that there was only a small difference between the annual volume of water that entered the reservoir and the annual volume of water that was released from the reservoir. Large spatial and temporal variations in concentrations of the metals of concern occurred during the study.The median and maximum concentrations of dissolved and total aluminum, iron, copper, cadmium, manganese, and zinc were larger upstream from the reservoir than downstream from the reservoir. The largest concentrations of dissolved aluminum, iron, copper, cadmium, manganese, and zinc generally occurred between mid-June and November. Throughout the study, aluminum was transported into the reservoir predominantly in the particulate or suspended form. Downstream from the reservoir, the suspended-aluminum fraction was predominant only during the pre-peak snowmelt and peak snowmelt

  9. Digital data sets that describe aquifer characteristics of the Tillman terrace and alluvial aquifer in southwestern Oklahoma (United States)

    Becker, C.J.; Runkle, D.L.; Rea, Alan


    ARC/INFO export and nonproprietary format files This diskette contains digitized aquifer boundaries and maps of hydraulic conductivity, recharge, and ground-water level elevation contours for the Tillman terrace and alluvial aquifer in southwestern Oklahoma. The Tillman terrace aquifer encompasses the unconsolidated terrace deposits and alluvium associated with the North Fork of the Red River and the Red River in the western half of Tillman County. These sediments consist of discontinuous layers of clay, sandy clay, sand, and gravel. The aquifer extends over an area of 285 square miles and is used for irrigation and domestic purposes. Granite and the Hennessey Formation outcrop in northern parts of the aquifer where alluvial deposits are absent. These outcrops were included as part of the aquifer in a thesis that modeled the ground-water flow in the aquifer. Most of the aquifer boundaries and some of the lines in the hydraulic conductivity and recharge data sets were extracted from a published digital surficial geology data set based on a scale of 1:250,000. Most of the lines in the hydraulic conductivity, recharge, and 1969 water-level elevation contour data sets, and one line in the aquifer boundary data set were digitized from a paper map published at a scale of 1:249,695 in a thesis in which the ground-water flow in the aquifer was modeled. Ground-water flow models are numerical representations that simplify and aggregate natural systems. Models are not unique; different combinations of aquifer characteristics may produce similar results. Therefore, values of hydraulic conductivity and recharge used in the model and presented in this data set are not precise, but are within a reasonable range when compared to independently collected data.

  10. Refurbishment and extension of the terrace of Restaurant No.1

    CERN Multimedia


    Work to refurbish and extend part of the terrace of Restaurant No.1 started in the first week of October and should last about two months. This is just a small part of the wide-ranging site infrastructure consolidation programme that began in April 2009. The new terrace, covering a surface area of 1770 m2 (compared with 1650 m2 today), is scheduled to be completed by the end of 2010 and will run all the way around the Restaurant No.1 extension. Work on the latter will affect part of Building 501 during the period from April to October 2010. The new dining room will seat some 275 additional customers (see picture). Part of the Cedars car-park will remain closed until some time in December to provide site access for trucks transporting construction materials, plant, etc. CERN Bulletin

  11. Physical and chemical characteristics of Terrace Reservoir, Conejos County, Colorado, May 1994 through May 1995; interim report (United States)

    Stogner, Sr., Robert W.; Edelmann, Patrick; Walton-Day, Katherine


    Terrace Reservoir receives drainage of low-pH, metal-enriched water from mineralized areas, including the Summitville Mine, within the AlamosaRiver Basin. Drainage from the Summitville Mine has contributed a substantial part of the metal load to Terrace Reservoir. From May 1994 through May 1995, a study was done by the U.S. Geological Survey, in cooperation with the U.S. Environmental Protection Agency, to evaluate the physical and chemical characteristics of Terrace Reservoir.Terrace Reservoir was thermally stratified from about mid-May through August 1994. Thermal stratification was absent from September\\x111994through March 1995. During periods of stratification, underflow of the Alamosa River was predominant, and residence times of the underflow were shortened by 40 to 75\\x11percent of the theoretical residence times for a well-mixed reservoir. Transport and deposition of suspended solids in Terrace Reservoir varied spatially and temporally. Most of the suspended solids were deposited in Terrace Reservoir. The concentration of dissolved oxygen in the reservoir varied little spatially or temporally and generally was within a few tenths of the dissolved-oxygen concentration of the inflow. The pH of water in the reservoir generally ranged from about 4.0 to about 7.0, depending on date, depth, and location. The largest pH values were measured during May. A markeddecrease of about 1.5\\x11pH units occurred at site T5 in the reservoir about mid-June. The pH of the reservoir remained at or below 5.5 from mid-June through November. Dissolved-metal concentrations varied spatially and temporally in response to several factors, which included inflow characteristics, reservoir stratification and mixing, inflow-routing and flow-through patterns, residence times, sedimentation, dissolved oxygen, and pH.Inflow chemistry is the dominant controlling factor of metal chemistry within Terrace Reservoir.During periods of stratification, large vertical variations in metal

  12. Miocene drowning of temperate (Foramol) carbonate platform: upper Miami Terrace

    Energy Technology Data Exchange (ETDEWEB)

    Carannante, G.; Simone, L.; Neumann, C.


    Oligocene neritic rocks dredged from 350 m on the upper Miami Terrace exhibit repeated phosphatization as well as a filled void system containing post-Burdigalian foraminifera. During drowning, a neritic hardground was subjected to both pelagic deposition (infills) and repeated marine exposure (borings, P-coatings, etc). The neritic grainstone-packstone contains large benthic foraminifera, red algae, bryozoans, pelecypods, ahermatypic corals, echinoids, and some planktonic foraminifera. This composition association is the Foramol type characteristic of temperate to subtropical neritic environments such as the present Mediterranean, Brazilian, and New Zealand shelves. These temperate sediments derive from the local biocoenose, and accumulate slowly in deep sheets of loose skeletal debris. They become relict seaward where they are often bored, corroded, stained, glauconitized, and cemented into hardgrounds. Locally, hemipelagic cover might produce a palimpsest sequence. Recent Foramol-type platforms are undergoing drowning. The Miami Terrace is compared to very similar Miocene Foramol-type platforms now exposed in the southern Apennines. Both are characterized by neritic sequences passing upward into hemipelagics, via a palimpsest interval marked by glauconitic, phosphatic, iron-stained grains often mineralized into hardgrounds. The drowning of the Miami Terrace hence coincided with and, the authors suppose, was a result of the shift from a rapid, oligotrophic, tropical accumulation to a slow, temperate, eutrophic carbonate accumulation caused in turn by a temporary paleo-oceanographic shift to cooler, richer, neritic conditions within the history of this now subtropical setting.

  13. Twenty Years of KSHV

    Directory of Open Access Journals (Sweden)

    Yuan Chang


    Full Text Available Twenty years ago, Kaposi’s sarcoma (KS was the oncologic counterpart to Winston Churchill’s Russia: a riddle, wrapped in a mystery, inside an enigma. First described by Moritz Kaposi in 1872, who reported it to be an aggressive skin tumor, KS became known over the next century as a slow-growing tumor of elderly men—in fact, most KS patients were expected to die with the tumor rather than from it. Nevertheless, the course and manifestations of the disease varied widely in different clinical contexts. The puzzle of KS came to the forefront as a harbinger of the AIDS epidemic. The articles in this issue of Viruses recount progress made in understanding Kaposi’s sarcoma herpesvirus (KSHV since its initial description in 1994.

  14. River Incision and Knickpoints on the Flank of the Yellowstone Hotspot — Alpine Canyon of the Snake River, Wyoming (United States)

    Tuzlak, D.; Pederson, J. L.


    Understanding patterns of deformation and testing geophysical models in the dynamic region of the Yellowstone Hotspot requires Quaternary-scale records of incision and uplift, which are currently absent. This study examines fluvial terraces and longitudinal-profile metrics along Alpine Canyon of the Snake River, WY. Because the Snake is the only regional river crossing from the uplifting Yellowstone Plateau and flowing into the subsiding Eastern Snake River Plain, it provides an opportunity to investigate both ends of the phenomenon. Field observations through Alpine Canyon indicate that Pleistocene incision rates in this region are relatively high for the interior western U.S., that the river switches between bedrock and alluvial forms, and that incision/uplift is not uniform. Two endmembers of regional deformation may be tested: 1) the arch of high topography surrounding Yellowstone is uplifting and terraces converge downstream as incision rates decrease towards the Snake River Plain, or 2) baselevel fall originates at the subsiding Snake River Plain and terraces diverge as incision rates increase downstream. Datasets include surficial mapping, rock strength measurements, surveying of the longitudinal profile and terraces using RTK-GPS, optically stimulated luminescence dating of fluvial-terrace deposits, and investigation of drainages through ksn and χ analyses. Initial results indicate that there are four primary terrace deposits along the canyon, three of which are timed with glacial epochs. Considering the relative heights of terrace straths and preliminary ages, incision rates are indeed relatively high. There is a major knickzone covering the last 15 km of the canyon that is also reflected in tributary profiles and is consistent with a wave of incision propagating upstream, favoring the second endmember of active baselevel fall downstream.

  15. Top at Twenty

    CERN Document Server


    The "Top at Twenty" workshop is dedicated to the celebration of 20 years since the top quark discovery at Fermilab in 1995. Speakers from all experiments capable of studying top quark, ATLAS, CDF, CMS and DZero, will present the most recent results of the top quark studies based on Run II of the Tevatron and Run I of the LHC. Reviews of such fundamental measurements as mass of the top quark, its spin, charge and production properties are planned with some of them orders of magnitude better in precision in comparison with original CDF and DZero papers announcing the top quark discovery. Measurements of top quark production and decay that illuminate the nature of the Higgs boson and seek new phenomena will be presented. Theoretical talks on how the top quark fits into the Standard Model and its potential extensions will also be presented. This workshop will complement the yearly Top Workshop which is held in September and will benefit from many new results expected to be presented at winter conferences in 2015...

  16. Pedimentation versus debris-flow origin of plateau-side desert terraces in southern Utah. (United States)

    Williams, V.S.


    Plateau-side terraces in arid areas around the world are commonly described as pediment remnants, although, in many cases, they may have been formed by debris-flow deposition. Pediments do exist in the area of the Aquarius and Kaiparowits Plateaus of southern Utah; however, many alluvial terraces that were classified by previous workers as pediments are actually formed of thick deposits of sediment released into valleys by episodic landslide events. Although both pediment and debris-flow depositional terraces have smooth, alluvium-covered upper surfaces, the two can be distinguished by the shape of the underlying bedrock surface and the process of formation. The relation of younger terraces to landsliding is clear, because the terrace surfaces are graded to the toes of slide lobes, but the origin of older terraces is less obvious, because older lobes of slide debris have generally been removed by erosion. -from Author

  17. Narrowing of Terrace-width Distributions During Growth on Vicinals (United States)

    Hamouda, Ajmi Bh.; Pimpinelli, A.; Einstein, T. L.


    Using kinetic Monte Carlo simulations for a generic minimal SOS model of vicinal surfaces, we compute the terrace-width distributions (TWDs) as a function of incident flux during homoepitaxial growth. We show that the distribution narrows markedly, U.B.P.-Clermont 2 as though there were a flux-dependent repulsion between steps, until the step picture fails at high flux. Using a Fokker-Planck approach, we analyze the evolution and saturation of this narrowing. We compare with a 1D model and with our simulations for narrowing due to an Ehrlich-Schwoebel barrier.

  18. Andean terraced hills (a use of satellite imagery)

    CERN Document Server

    Sparavigna, Amelia Carolina


    The aim of this paper is in stimulating the use of satellite imagery, in particular the free service of Google Maps, to investigate the distribution of the agricultural technique of terraced hills in Andean countries, near Titicaca Lake. In fact, satellite maps can give a clear view of the overall surface modified by human work, being then a precious help for on-site archaeological researches and for historical analysis. Satellite imagery is also able to give the distribution of burial and worship places. The paper discusses some examples near the Titicaca Lake.

  19. Terraced agriculture protects soil from erosion: Case studies in Madagascar (United States)

    Rabesiranana, Naivo; Rasolonirina, Martin; Fanantenansoa Solonjara, Asivelo; Nomenjanahary Ravoson, Heritiana; Mabit, Lionel


    - Soil degradation is a major concern in Madagascar but quantitative information is not widely available. Due to its impact on the sustainability of agricultural production, there is a clear need to acquire data on the extent and magnitude of soil erosion/sedimentation under various agricultural practices in order to promote effective conservation strategies. Caesium-137 and 210Pbex fallout radionuclides (FRNs) possess particular characteristics that make them effective soil tracers for erosion studies. After fallout, 137Cs and 210Pbex are rapidly adsorbed onto fine soil particles. But to date, combined use of these FRNs has never been used to document soil erosion in Madagascar. The study area is located 40 km east of Antananarivo, in Madagascar highlands. Two adjacent cultivated fields have been selected (i.e. a sloped field and a terraced field) as well as an undisturbed reference site in the vicinity of these agricultural fields. Soil samples were collected along downslope transects using motorized corer. The 137Cs and 210Pb gamma analysis were performed at the Institut National des Sciences et Techniques Nucléaires (INSTN-Madagascar) using a high resolution and low background N-type HPGe detector. Results showed that at the terraced field, 137Cs and 210Pbex inventories reached 145 Bq/m2 to 280 Bq/m2 and 2141 Bq/m2 to 4253 Bq/m2, respectively. At the sloped field, the 137Cs and 210Pbex inventories values ranged from 110 Bq/m2 to 280 Bq/m2 and from 2026 Bq/m2 to 4110 Bq/m2, respectively. The net soil erosion determined for the sloped field were 9.6 t/ha/y and 7.2 t/ha/y for 137Cs and 210Pbex methods, respectively. In contrast, at the terraced field, the net soil erosion rates reached only 3.4 t/ha/y and 3.8 t/ha/y, respectively. The preliminary results of this research highlighted that terraced agricultural practice provides an efficient solution to protect soil resources of the Malagasy highlands.

  20. Marine terraces; datum planes for study of structural deformation (United States)

    Huber, N.K.


    Along the earthquake-prone coastal area of north-central California, geologists are searching for criteria to establish the nature, extent, and rate of crustal movement or deformation that may be related to activity along known or postulated faults. This search has led to a study of marine terraces along the coast between San Francisco and Santa Cruz in the area that is transected by the Seal Cove-San Gregorio-Palo Colorado fault, a branch of the San Andreas fault system. 

  1. Preliminary evidence for 17 coastal terraces on Fildes Peninsula, King George Island, Antarctica

    Institute of Scientific and Technical Information of China (English)

    CHU Zhuding; YIN Xuebin; SUN Liguang; WANG Yuhong


    This study confirms the presence of 17 coastal terraces on Fildes Peninsula, Antarctica based on field observations and grain size analysis. The terraces formed by isostatic uplift during climate warming and glacier melting, and each level corresponds to a relatively stable period of climate. The grain size characteristics indicate an overlapping sedimentary origin for the sediments on the coastal terraces. The consistency of regional sea level rise, climate change, and glacial area suggest the presence of similar coastal terraces on King George Island since 18.0 ka.

  2. Characterizing hydrological processes on loess slopes using electrical resistivity tomography - A case study of the Heifangtai Terrace, Northwest China (United States)

    Zeng, R. Q.; Meng, X. M.; Zhang, F. Y.; Wang, S. Y.; Cui, Z. J.; Zhang, M. S.; Zhang, Y.; Chen, G.


    From the perspective of engineering geology, loess has long been considered as a homogeneous and porous material. It is commonly believed that water penetrates loess via pores and in some cases causing mass movements. However, several researchers have expressed doubts about this mechanism as a cause of slope failures in loess, and moreover the actual hydrological processes operating in loess deposits and their effect on slope failures have not been fully investigated. Here we present the results of an electrical resistivity survey of the Heifangtai loess terrace in northwestern China, designed to characterize the hydrological processes in loess slopes and their relationship with slope failures. The Heifangtai loess terrace is located on the fourth terrace of the Yellow River and consists of 57-m-thickness of aeolian loess. 2D and 3D electrical resistivity tomography (ERT) was used to monitor the movement of ground water before and after irrigation and rainfall events and the evolution of a sink hole in the toe of the landslide deposits. Our main findings are as follows: (1) Based on the 2D ERT results, the depth of infiltration into the thick unsaturated loess is not more than 5 m in the profile at the top of the landslide. (2) Electrical resistivity decreased as a result of water infiltration through sinkholes, and this process can increase the soil water content and induce soil liquefaction which can eventually result in land sliding. (3) Landslide deposits block the groundwater drainage channels through the loess, which results in the concentration of water in the toe of the landslide. Consequently, groundwater together with rainfall, triggers the failure of sinkholes or cracks, which may induce a continuing process of new slope failures at the sites of past landslide.

  3. Active overbank deposition during the last century, South River, Virginia (United States)

    Pizzuto, Jim; Skalak, Katherine; Pearson, Adam; Benthem, Adam


    We quantify rates of overbank deposition over decadal to centennial timescales along the South River in Virginia using four independent methods. Detailed mercury profiles sampled adjacent to the stream channel preserve the peak historic mercury concentration on suspended sediment dating from 1955 to 1961 and suggest sedimentation rates of 8 to 50 cm/100 years. Sediment accumulation over the roots of trees suggest rates of 0 to 100 cm/100 years, with significantly higher values on levees and lower values on floodplains farther from the channel. Profiles of 137Cs and 210Pb from two eroding streambanks are fit with an advection-diffusion model calibrated at an upland reference site; these methods suggest sedimentation rates of 44 to 73 cm/100 years. Mercury inventories from 107 floodplain cores, combined with a previously published reconstruction of the history of mercury concentration on suspended sediment, provide spatially comprehensive estimates of floodplain sedimentation: median sedimentation rates are 3.8 cm/100 years for the South River. Hydrologic Engineering Center-River Analysis System (HEC-RAS) modeling demonstrates that the floodplain of the South River remains hydraulically connected to the channel: 56% of the 100-year floodplain is inundated every two years, and 83% of the floodplain is inundated every five years. These results, combined with previously published data, provide the basis for a regional synthesis of floodplain deposition rates since European settlement. Floodplain sedimentation rates were high following European settlement, with published estimates ranging from 50 to 200 cm/100 years. Sedimentation rates decreased by 1 to 2 orders of magnitude during the twentieth and twenty-first centuries; but despite these lower sedimentation rates, floodplains continue to store a significant fraction of total suspended sediment load. Many floodplains of the mid-Atlantic region are active landforms fully connected to the rivers that flow within them

  4. Adaptive self-organization of Bali's ancient rice terraces. (United States)

    Lansing, J Stephen; Thurner, Stefan; Chung, Ning Ning; Coudurier-Curveur, Aurélie; Karakaş, Çağil; Fesenmyer, Kurt A; Chew, Lock Yue


    Spatial patterning often occurs in ecosystems as a result of a self-organizing process caused by feedback between organisms and the physical environment. Here, we show that the spatial patterns observable in centuries-old Balinese rice terraces are also created by feedback between farmers' decisions and the ecology of the paddies, which triggers a transition from local to global-scale control of water shortages and rice pests. We propose an evolutionary game, based on local farmers' decisions that predicts specific power laws in spatial patterning that are also seen in a multispectral image analysis of Balinese rice terraces. The model shows how feedbacks between human decisions and ecosystem processes can evolve toward an optimal state in which total harvests are maximized and the system approaches Pareto optimality. It helps explain how multiscale cooperation from the community to the watershed scale could persist for centuries, and why the disruption of this self-organizing system by the Green Revolution caused chaos in irrigation and devastating losses from pests. The model shows that adaptation in a coupled human-natural system can trigger self-organized criticality (SOC). In previous exogenously driven SOC models, adaptation plays no role, and no optimization occurs. In contrast, adaptive SOC is a self-organizing process where local adaptations drive the system toward local and global optima.

  5. Mapping the environmental risk potential on surface water of pesticide contamination in the Prosecco's vineyard terraced landscape (United States)

    Pizarro, Patricia; Ferrarese, Francesco; Loddo, Donato; Eugenio Pappalardo, Salvatore; Varotto, Mauro


    Intensive cropping systems today represent a paramount issue in terms of environmental impacts, since agricultural pollutants can constitute a potential threat to surface water, non-target organisms and aquatic ecosystems. Levels of pesticide concentrations in surface waters are indeed unquestionably correlated to crop and soil management practices at field-scale. Due to the numerous applications of pesticides required, orchards and vineyards can represent relevant non-point sources for pesticide contamination of water bodies, mainly prompted by soil erosion, surface runoff and spray drift. To reduce risks of pesticide contamination of surface water, the Directive 2009/128/CET imposed the local implementation of agricultural good practices and mitigation actions such as the use of vegetative buffer filter strips and hedgerows along river and pond banks. However, implementation of mitigation actions is often difficult, especially in extremely fragmented agricultural landscapes characterized by a complex territorial matrix set up on urban sprawling, frequent surface water bodies, important geomorphological processes and protected natural areas. Typically, such landscape matrix is well represented by the, Prosecco-DOCG vineyards area (NE of Italy, Province of Treviso) which lays on hogback hills of conglomerate, marls and sandstone that ranges between 50 and 500 m asl. Moreover such vineyards landscape is characterized by traditional and non-traditional agricultural terraces The general aim of this paper is to identify areas of surface water bodies with high potential risk of pesticide contamination from surrounding vineyards in the 735 ha of Lierza river basin (Refrontolo, TV), one of the most representative terraced landscape of the Prosecco-DOCG area. Specific aims are i) mapping terraced Prosecco-DOCG vineyards, ii) classifying potential risk from pesticide of the different areas. Remote sensing technologies such as four bands aerial photos (RGB+NIR) and Light

  6. Time scale for degradation and erosion of archaeological terraces in the Judea Mountains, Israel (United States)

    Porat, Naomi; Elinson, Rotem; Ben Dor, Eyal; Avni, Yoav; Gadot, Yuval


    The fate of mountain bench terraces which have been abandoned in ancient times is puzzling. On the one hand recently abandoned terraces undergo rapid degradation by walls crumbling, leading to soil being washed by rain water out of breaches in the walls, suggesting that within a short time all soil would be washed down-slope. On the other hand slopes with degraded terraces appear to still retain much soil even though only faint remains of the terraces exist. Moreover, if soil is rapidly eroded down-slope when terraces are no longer maintained, where do subsequent terrace builders find the soil to fill behind the stone walls? These questions were addressed as part of a larger study on the chronology of terraces in the Judea Mountains, Israel. Previous OSL dating of terrace soils in the region showed that the majority of the maintained terraces were constructed during the past 700 years, and only occasionally older ages were obtained for the soil at the very base of these terraces. Concerns were raised that soil erosion caused earlier events of terrace construction to disappear. To check if terraces and soils indeed erode entirely and how long this might take, we selected a relatively smooth hill slope showing small patches of limestone bedrock as well as remains of highly degraded sets of terraces. Three pits were excavated in soils within three different terrace remains down to bedrock, some to a depth of 2 m, and samples for OSL dating were collected from the exposed soil sections. In all three pits the lowermost samples gave ages of 3000-4500 years before the present, possibly the natural soils before any human intervention. However samples from a depth of 35-45 cm gave ages of 350-200 years, providing the last time the soil at that depth was exposed to sunlight. This suggests that the terraces were abandoned in the past 200 years or so and since then degraded. However the thick soil present on most of the slope suggests that after the first stage of rapid

  7. Research on Remote Sensing recognition features of Yuan Yang Terraces in Yunnan Province (China) (United States)

    Xiang, Jie; Chen, Jianping; Lai, ZiLi; Yang, Wei


    Yuan Yang terraces is one of the most famous terraces in China, and it was successfully listed in the world heritage list at the 37th world heritage convention. On the one hand, Yuan Yang terraces retain more soil and water, to reduce both hydrological connectivity and erosion, and to support irrigation. On the other hand, It has the important tourism value, bring the huge revenue to local residents. In order to protect and make use of Yuan Yang terraces better, This study analyzed the spatial distribution and spectral characteristics of terraces:(1) Through visual interpretation, the study recognized the terraces based on the spatial adjusted remote sensing image (2010 Geoeye-1 with resolution of 1m/pix), and extracted topographic feature (elevation, slope, aspect, etc.) based on the digital elevation model with resolution of 20m/pix. The terraces cover a total area of about 11.58Km2, accounted for 24.4% of the whole study area. The terraces appear at range from 1400m to 1800m in elevation, 10°to 20°in slope, northwest to northeast in aspect; (2) Using the method of weight of evidence, this study assessed the importance of different topographic feature. The results show that the sort of importance: elevation>slope>aspect; (3) The study counted the Normalized Difference Vegetation Index (NDVI) changes of terraces throughout the year, based on the landsat-5 image with resolution of 30m/pix. The results show that the changes of terraces' NDVI are bigger than other stuff (e.g. forest, road, house, etc.). Those work made a good preparations for establishing the dynamic remote sensing monitoring system of Yuan Yang terraces.

  8. Luminescence Dating of Marine Terrace Sediments Between Trabzon and Rize, Eastern Black Sea Basin: Preliminary Results (United States)

    Softa, Mustafa; Spencer, Joel Q. G.; Emre, Tahir; Sözbilir, Hasan; Turan, Mehmet


    Quaternary marine terraces in the coastal region of Pontides in Northeastern Turkey are valuable archives of past sea level change. Until recently, dates of raised marine terraces undeciphered in the coastal region between Trabzon and Rize because of chronologic limitations. In this paper was to determine ages of the terrace deposits by applying optically stimulated luminescence (OSL) dating methods using single aliquot regenerative dose (SAR) techniques on quartz minerals from extracted marine terraces. Several samples were collected from three orders of Quaternary marine terraces which are reproducible at all sampling location in between cities of Trabzon and Rize, Turkey, coastal of Eastern Pontides, at the front of the thrust system. The terrace deposits mainly consist of clays, silts, sands and gravels. The sediments in these deposits are mainly derived from basaltic, andesitic, and limestone geology, and have elipsoid, square and flat shapes. The terrace deposits have heights ranging from 1 to 17 meters and increases in height and thickness from west to east. Initial OSL results from 1 mm and 3 mm quartz aliquots demonstrate good luminescence characteristics. Preliminary equivalent dose analysis results ranging from 17.6 Gy to 79.6 Gy have been calculated using the Central Age Model (CAM) and Minimum Age Model (MAM). According to ages obtained from three separate terrace is ~8 ka, ~42 ka and ~78 ka, respectively. Results of marine terrace sediments indicate this region has three sedimentation periods and coastal region of Pontides has been remarkably tectonically active since latest Pleistocene to earlier Holocene. This study will present preliminary OSL dating results obtained from samples of Quaternary marine terrace formation. Keywords: optically stimulated luminescence (OSL) dating, single grain, marine terraces, Eastern Pontides.

  9. 100 kyr fluvial cut-and-fill terrace cycles since the Middle Pleistocene in the southern Central Andes, NW Argentina (United States)

    Tofelde, Stefanie; Schildgen, Taylor F.; Savi, Sara; Pingel, Heiko; Wickert, Andrew D.; Bookhagen, Bodo; Wittmann, Hella; Alonso, Ricardo N.; Cottle, John; Strecker, Manfred R.


    Fluvial fill terraces in intermontane basins are valuable geomorphic archives that can record tectonically and/or climatically driven changes of the Earth-surface process system. However, often the preservation of fill terrace sequences is incomplete and/or they may form far away from their source areas, complicating the identification of causal links between forcing mechanisms and landscape response, especially over multi-millennial timescales. The intermontane Toro Basin in the southern Central Andes exhibits at least five generations of fluvial terraces that have been sculpted into several-hundred-meter-thick Quaternary valley-fill conglomerates. New surface-exposure dating using nine cosmogenic 10Be depth profiles reveals the successive abandonment of these terraces with a 100 kyr cyclicity between 75 ± 7 and 487 ± 34 ka. Depositional ages of the conglomerates, determined by four 26Al/10Be burial samples and U-Pb zircon ages of three intercalated volcanic ash beds, range from 18 ± 141 to 936 ± 170 ka, indicating that there were multiple cut-and-fill episodes. Although the initial onset of aggradation at ∼1 Ma and the overall net incision since ca. 500 ka can be linked to tectonic processes at the narrow basin outlet, the superimposed 100 kyr cycles of aggradation and incision are best explained by eccentricity-driven climate change. Within these cycles, the onset of river incision can be correlated with global cold periods and enhanced humid phases recorded in paleoclimate archives on the adjacent Bolivian Altiplano, whereas deposition occurred mainly during more arid phases on the Altiplano and global interglacial periods. We suggest that enhanced runoff during global cold phases - due to increased regional precipitation rates, reduced evapotranspiration, or both - resulted in an increased sediment-transport capacity in the Toro Basin, which outweighed any possible increases in upstream sediment supply and thus triggered incision. Compared with two

  10. Nutrient Losses by Runoff and Sediment from the Taluses of Orchard Terraces

    NARCIS (Netherlands)

    Duran Zuazo, V.H.; Martinez Ray, A.; Aguilar Ruiz, J.


    The nutrient fluxes of nitrate, ammonium, phosphorus and potassium in runoff and sediments were evaluated over a two-year period (1999¿2000) on the taluses of terraces, in a zone of intense subtropical orchard cultivation (SE Spain). The erosion plots were located on a terrace of 214% (65°) slope, a

  11. Designing terraces for the rainfed farming region in Iraq using the RUSLE and hydraulic principles

    Directory of Open Access Journals (Sweden)

    Mohammad H. Hussein


    Full Text Available The rainfed region in Iraq comprises an area of more than 5 million ha of forest, grazing and farmland areas. Except the plains, the region suffers from moderate to severe water erosion due mainly to overgrazing and land mismanagement. Due to population growth and the shortage in water resources, an expansion in land used for agriculture in the region is expected. Terracing is an option when utilizing sloping land for agricultural production. A terrace design criterion was developed for the region in which terrace spacing was determined using the Revised Universal Soil Loss Equation (RUSLE; terrace channel specifications were determined using conventional hydraulic computations. Analyses showed that terracing is feasible on rolling and hilly sloping land in the high rainfall zone (seasonal rainfall >600 mm where economic crops are grown to offset the high cost of terrace construction and maintenance. In the medium and low rainfall zones (seasonal rainfall 400–600 mm and 300–400 mm, terracing for water erosion control is generally not needed on cultivated land less than 10% in slope where wheat and barley crops are normally grown; however, pioneer research projects are needed to assess the feasibility of terraces of the level (detention type to conserve rain water in these two zones for a more successful rainfed farming venture.

  12. Spatial Regularities of Placing the Halophytic Associations of Elton Lakeside Terrace

    Directory of Open Access Journals (Sweden)

    Kanishchev Sergey Nikolaevich


    Full Text Available The article shows the results of research carried out in 2012-2013 in the Eltonsky natural park. This area is located in the southeast of the European part of Russia and includes Elton Lake and its surrounding landscapes - one of the most valuable natural territorial complexes of southern Russia. The objective of the research is to reveal patterns of distribution of halophytic associations. The author applies the method of landscape profiling, conducts geobotanical descriptions and selects soil samples to determine soil moisture coefficient over the horizons. The results of this study characterize the patterns of distribution of halophytic plant associations of Elton lakeside terrace. The article presents the dependence of the distribution of plant associations basin lake Elton depending on soil moisture and relative elevation. The results indicate that the highest soil moisture is observed at the depths of 35-55 cm. Landscaped profiles showed that Halocnemum strobilaceum and Atriplex cana occupy micro lowlands. The land, located over the surrounding space is covered with Suaeda salsa and cereal associations. The communities of Salicornia perennans dominate in the vast fields of salt lakeside. Phragmites australis prevails along the edge of the Malaya Smorogda river.

  13. Outlook: The Next Twenty Years

    Energy Technology Data Exchange (ETDEWEB)

    Murayama, Hitoshi


    I present an outlook for the next twenty years in particle physics. I start with the big questions in our field, broken down into four categories: horizontal, vertical, heaven, and hell. Then I discuss how we attack the bigquestions in each category during the next twenty years. I argue for a synergy between many different approaches taken in our field.

  14. Digital data sets that describe aquifer characteristics of the Tillman terrace and alluvial aquifer in southwestern Oklahoma (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital aquifer boundaries for the Tillman terrace and alluvial aquifer in southwestern Oklahoma. The Tillman terrace aquifer encompasses...

  15. Digital data sets that describe aquifer characteristics of the Tillman terrace and alluvial aquifer in southwestern Oklahoma (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital polygons of constant recharge values for the Tillman terrace and alluvial aquifer in southwestern Oklahoma. The Tillman terrace and...

  16. Digital data sets that describe aquifer characteristics of the Tillman terrace and alluvial aquifer in southwestern Oklahoma (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital water-level elevation contours for the Tillman terrace and alluvial aquifer in southwestern Oklahoma. The Tillman terrace and...

  17. Genetic differences between hatchery and wild steelhead for survival, growth, dispersal, and male maturation in a natural stream (Study site: Twenty-Mile Creek; Stocks: Dworshak hatchery and Selway River wild; Year classes: 1994 and 1995): Chapter 3 (United States)

    Rubin, Stephen P.; Reisenbichler, Reginald R.; Hensleigh, Jay E.; Wetzel, Lisa A.; Baker, Bruce M.; Leonetti,; Stenberg, Karl D.; Slatton, Stacey L.; Rubin, Stephen P.; Reisenbichler, Reginald R.; Wetzel, Lisa A.; Hayes, Michael C.


    This study was initiated in the early 1990s to provide managers with data comparing genetic fitness for natural rearing, as measured by survival of juveniles in freshwater, between steelhead Oncorhynchus mykiss from Dworshak National Fish Hatchery and wild steelhead from the Clearwater River, Idaho. We artificially spawned hatchery steelhead and wild steelhead from the Selway River, a Clearwater River tributary, released the resulting genetically marked (at the PEPA allozyme locus) progeny (HxH, HxW from hatchery females and wild males, and WxW) as unfed fry in a second order tributary of the South Fork Clearwater River, and monitored fish residing in the stream or emigrating from it for five years. Barrier falls prevented access to the stream by naturally produced steelhead. Over 90% of the emigrants were one or two years of age and too small to be smolts (mean fork length at age-2 = 103 mm). Per fry released, the HxH cross produced 0.64-0.83 times as many emigrants as the WxW cross (P<0.05). The HxH cross produced 0.63 times as many age-4 residuals as the WxW cross for one year-class (P=0.051) and 0.68 times as many for the other (ns). Survival from age-1 to age-4 was lower for HxH than for WxW residuals of one year-class (P<0.05) and survival from age-2 to age-4 may have been lower for HxH than for WxW residuals of the other (P=0.062). Collectively, these results indicate lower survival for HxH than for WxW fish. Size was often greater for HxH than for WxW fish indicating faster growth for the former, and condition factor was also usually greater for HxH than for WxW fish. Dispersal of fry from release sites and emigration of one- and two-year olds from the study stream were greater for WxW than for HxH fish, and apparently neither was from competitive displacement of small by larger fish. Incidence of flowing milt was higher for HxH than for WxW fish at age-2. Peak incidence of flowing milt for older residuals was similar among crosses (about 50%), but the peak

  18. Taming the torrents: The hydrological impacts of ancient terracing practices in Jordan (United States)

    Al Qudah, Khaldoon; Abdelal, Qasem; Hamarneh, Catreena; Abu-Jaber, Nizar


    Extensive terracing was an important component of the water and agricultural management regime of Nabatean Petra. The exact function(s) of these terraces, qualitatively and quantitatively, is herein investigated. Field studies and computer modeling for two sites within the drainage basin of Petra show that these terraces were highly effective at reducing surface runoff. Different design features seem to have been adapted in order to achieve different objectives at varying sites. For example, the Beidha site in the lower reaches of the catchment area falls within the higher relief Ordovician Disi Sandstone formation area. Here, the terrace system was designed to slow water flow and trap sediments. The terracing greatly reduced surface water flow through the entrapment of sandy loam sediments behind it. On the other hand, the Baqa'a site falls in the upper reaches of the drainage basin within the Upper Cretaceous Amman Silicified Limestone formation. The effect of the terrace system here on runoff is significant, but less than that seen at Beidha. This system was more suited for soil conservation and agriculture, as the soil here in its natural state already had a high infiltration rate. Neglect and abandonment of these terraces at both sites have led to increased runoff, as evidenced by the development of gullies and by periodic flooding downstream in the core of the ancient city. Based on the six modeled cases, terraces can minimize the surface flow by an average of 28%, with values as high as 90% when 2010 precipitation data were used. Conducting an intensive survey within the catchment area surrounding the ancient city of Petra, mapping the ancient terraces, and reviving their function may produce significant results in flood mitigation and control there.

  19. Environmental Impact Study of the Northern Section of the Upper Mississippi River. Pool 8. (United States)


    due to sand dune formation. These terrace provide a suitable place for people to settle and populate. However, outwash from these terraces tends to...income than is industrial activity and relates mainly to leisure-time activities of people using the Mississippi River for recreational purposes...burial mounds, historical battlegrounds or buildings, or existing settlements of 22 ethnic groups such as Amish communities. Because of the difficulty of


    Institute of Scientific and Technical Information of China (English)

    胡小飞; 潘保田; 高红山; 胡振波; 曹泊; 李清洋; 耿豪鹏


    Holocene terraces along most rivers in the NW China were well developed,while the process and mechanism about the Holocene terrace is poorly known.In the eastern Qilianshan Mountain (between 101 °30′E to 103°30′E and 37°00′N to 38°10′N),near Wuwei City,Holocene terrace is usually composed by 1 ~3 flights of sub-terraces,while this phenomenon is scarcely found with Pleistocene terraces.In order to disclose the mechanism of the formation the sub-terraces,we investigated the Holocene terraces in 13 river valley transections along 4 rivers(the Xiying,Jinta,Huangyang,and Gulang rivers) in the eastern Qilianshan Mountain.The depositing stratigraphy with each terrace was observed in detail and terrace age was accurately determined by 14C dating method in the relative sediment of the Holocene terrace.Except the Xiying River,2 ~ 3 flights of Holocene sub-terraces were developed along other 3 rivers,especially along the Jinta River,the sub-terraces are distinct.Within each terrace stratigraphy,Holocene paleosol was usually developed in the overlying loess or colluvial sediment above the fluvial gravel layer.Analysis results of terrace ages indicate that river incisions mainly cumulated on the period of 7.5 ~ 3.0ka B.P.Based on the comparison between river incision ages and climatic records,we find that during the periods (5.9 ~7.2ka B.P.,4.2 ~5.2 ka B.P.and 2.4 ~ 3.3ka B.P.) of river incision,the climate was relative wet in the study area.This evidence may suggest that river incisions happened while the discharge increases and the sediment supply decreases according to increasing precipitation and better vegetation cover.The multiple incision periods in Holocene also suggest that one regular river incision(like Pleistocene terraces)is completed by multiple short-lived incisions and aggradations,and due to the local river valley situation,this process can be documented by small terraces staircases,or it will be erased by side erosion

  1. a sedimentologic analysis of terrace sediments from the pawmpawm ...

    African Journals Online (AJOL)


    trum of particle sizes, affect the hydraulics of flow as well as ... and soil materials in natural water courses and ..... River bar: a study in the significance of grain ... race Maintenance, Agricultural Experiment ... the central Appalachian Basin.

  2. Potentials and pitfalls of depth profile (10Be), burial isochron (26Al/10Be) and palaeomagnetic techniques for dating Early Pleistocene terrace deposits of the Moselle valley (Germany) (United States)

    Rixhon, Gilles; Cordier, Stéphane; May, Simon Matthias; Kelterbaum, Daniel; Szemkus, Nina; Keulertz, Rebecca; Dunai, Tibor; Binnie, Steven; Hambach, Ulrich; Scheidt, Stephanie; Brueckner, Helmut


    Throughout the river network of the Rhenish Massif the so-called main terraces complex (MTC) forms the morphological transition between a wide upper palaeovalley and a deeply incised lower valley. The youngest level of this complex (YMT), directly located at the edge of the incised valley, represents a dominant geomorphic feature; it is often used as a reference level to identify the beginning of the main middle Pleistocene incision episode (Demoulin & Hallot, 2009). Although the main terraces are particularly well preserved in the lower Moselle valley, a questionable age of ca. 800 ka is assumed for the YMT, mainly based on the uncertain extrapolation of controversially interpreted palaeomagnetic data obtained in the Rhine valley. In this study, we applied terrestrial cosmogenic nuclide (TCN) dating (10Be/26Al) and palaeomagnetic dating to Moselle fluvial sediments of the MTC. To unravel the spatio-temporal characteristics of the Pleistocene evolution of the valley, several sites along the lower Moselle were sampled following two distinct TCN dating strategies: depth profiles where the original terrace (palaeo-) surface is well preserved and did not experience a major post-depositional burial (e.g., loess cover); and the isochron technique, where the sediment thickness exceeds 4.5-5 m. One terrace deposit was sampled for both approaches (reference site). In addition, palaeomagnetic sampling was systematically performed in each terrace sampled for TCN measurements. The TCN dating techniques show contrasting results for our reference site. Three main issues are observed for the depth profile method: (i) an inability of the modeled profile to constrain the 10Be concentration of the uppermost sample; (ii) an overestimated density value as model output; and (iii) a probable concentration steady state of the terrace deposits. By contrast, the isochron method yields a burial age estimate of 1.26 +0.29/-0.25 Ma, although one sample showed a depleted 26Al/10Be ratio

  3. Terrace retro-reflector array for poloidal polarimeter on ITER. (United States)

    Imazawa, R; Kawano, Y; Ono, T; Kusama, Y


    A new concept of a terrace retro-reflector array (TERRA) as part of the poloidal polarimeter for ITER is proposed in this paper. TERRA reflects a laser light even from a high incident angle in the direction of the incident-light path, while a conventional retro-reflector array cannot. Besides, TERRA can be installed in a smaller space than a corner-cube retro-reflector. In an optical sense, TERRA is equivalent to a Littrow grating, the blaze angle of which varies, depending on the incident angle. The reflected light generates a bright and dark fringe, and the bright fringe is required to travel along the incident-light path to achieve the objects of laser-aided diagnostics. In order to investigate the propagation properties of laser light reflected by TERRA, we have developed a new diffraction formula. Conditions for the propagation of the bright fringe in the direction of the incident light have been obtained using the Littrow grating model and have been confirmed in a simulation applying the new diffraction formula. Finally, we have designed laser transmission optics using TERRA for the ITER poloidal polarimeter and have calculated the light propagation of the system. The optical design obtains a high transmission efficiency, with 88.6% of the incident power returned. These results demonstrate the feasibility of applying TERRA to the ITER poloidal polarimeter.

  4. Evaluating the strength of concrete structure on terrace houses (United States)

    Hasbullah, Mohd. Amran; Yusof, Rohana; Rahman, Mohd Nazaruddin Yusoff @ Abdul


    The concrete structure is the main component to support the structure of the building, but when concrete has been used for an extended period hence, it needs to be evaluated to determine the current strength, durability and how long it can last. The poor quality of concrete structures will cause discomfort to the user and, the safety will be affected due to lack of concrete strength. If these issues are not monitored or not precisely known performance, and no further action done then, the concrete structure will fail and eventually it will collapse. Five units of terrace houses that are built less than 10 years old with extension or renovations and have cracks at Taman Samar Indah, Samarahan, Sarawak have been selected for this study. The instrument used in this research is Ultrasonic Pulse Velocity (UPV), with the objective to determine the current strength and investigate the velocity of a pulse at the concrete cracks. The data showed that the average velocity of the pulse is less than 3.0 km/s and has shown that the quality of the concrete in the houses too weak scale / doubt in the strength of concrete. It also indicates that these houses need to have an immediate repair in order to remain secure other concrete structures.

  5. Biologic origin of iron nodules in a marine terrace chronosequence, Santa Cruz, California (United States)

    Schulz, M.S.; Vivit, D.; Schulz, C.; Fitzpatrick, J.; White, A.


    The distribution, chemistry, and morphology of Fe nodules were studied in a marine terrace soil chronosequence northwest of Santa Cruz, California. The Fe nodules are found at depths hematite with time. The abundance of soil Fe nodules increased with terrace age on the five terraces studied (aged 65,000-226,000 yr). Scanning electron microscopy (SEM) revealed Fe-oxide-containing fungal hyphae throughout the nodules, including organic structures incorporating fine-grained Fe oxides. The fine-grained nature of the Fe oxides was substantiated by M??ssbauer spectroscopy. Our microscopic observations led to the hypothesis that the nodules in the Santa Cruz terrace soils are precipitated by fungi, perhaps as a strategy to sequester primary mineral grains for nutrient extraction. The fungal structures are fixed by the seasonal wetting and dry cycles and rounded through bioturbation. The organic structures are compacted by the degradation of fungal C with time. ?? Soil Science Society of America. All rights reserved.

  6. Effectiveness of the GAEC standard of cross compliance retain terraces on soil erosion control

    Directory of Open Access Journals (Sweden)

    Paolo Bazzoffi


    Full Text Available The GAEC standard retain terraces of cross compliance prohibits farmers the elimination of existing terraces, with the aim to ensure the protection of soil from erosion. In the Italian literature there are not field studies to quantify the effects of the elimination or degradation of terraces on soil erosion. Therefore, the modeling approach was chosen and applied in a scenario analysis to evaluate increasing levels of degradation of stone wall terraces. The study was conducted on two sample areas: Lamole (700.8 ha, Tuscany and Costaviola (764.73 ha, Calabria with contrasting landscapes. The Universal Soil Loss Equation model (USLE was applied in the comparative assessment of the soil erosion risk (Mg . ha-1 . yr-1, by simulating five increasing intensity of terrace degradation, respectively: conserved partially damaged, very damaged, partially removed, removed, each of which corresponding to different values of the indexes of verification in case of infringement to GAEC standard provided for by the AGEA rules which have come into force since December 2009 (Agency for Agricultural Payments. To growing intensity of degradation, a progressive loss of efficacy of terraces was attributed by increasing the values of the LS factor (length and slope of USLE in relation with the local modification of the length and steepness of the slope between adjacent terraces. Basically, it was simulated the gradual return to the natural morphology of the slope. The results of the analysis showed a significant increase in erosion in relationship with increasing degradation of terraces. Furthermore, it is possible to conclude that the GAEC standard retain terraces is very effective with regard to the primary objective of reducing erosion. A further statistical analysis was performed to test the protective value of terraces against soil erosion in areas where agriculture was abandoned. The analysis was carried out by comparing the specific risk of erosion (Mg . ha-1

  7. A cultural interpretation of ethnic tourism: Case study of Honghe Hani Rice Terrace


    McDonald, Tom; Zhang, Ying; Chan, Jin Hooi


    The article discusses the challenges to ensure sustainable development in the UNESCO World Heritage Site of Honghe Rice Terraces in Yunnan, China. It takes a cultural interpretation of minority ethnic views on environmental conservation and protection.

  8. Digital data sets that describe aquifer characteristics of the Enid isolated terrace aquifer in northwestern Oklahoma (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digitized polygons of constant hydraulic conductivity values for the Enid isolated terrace aquifer in northwestern Oklahoma. The Enid...

  9. Desert agricultural terrace systems at EBA Jawa (Jordan) - Layout, water availability and efficiency (United States)

    Meister, Julia; Krause, Jan; Müller-Neuhof, Bernd; Portillo, Marta; Reimann, Tony; Schütt, Brigitta


    Located in the arid basalt desert of northeastern Jordan, the Early Bronze Age (EBA) settlement of Jawa is by far the largest and best preserved archaeological EBA site in the region. Recent surveys in the close vicinity revealed well-preserved remains of three abandoned agricultural terrace systems. In the presented study these archaeological features are documented by detailed mapping and the analysis of the sediment records in a multi-proxy approach. To study the chronology of the terrace systems optically stimulated luminescence (OSL) is used. In order to evaluate the efficiency of the water management techniques and its impact on harvest yields, a crop simulation model (CropSyst) under today's climatic conditions is applied, simulating crop yields with and without (runoff) irrigation. In order to do so, a runoff time series for each agricultural terrace system and its catchment is generated, applying the SCS runoff curve number method (CN) based on rainfall and soil data. Covering a total area of 38 ha, irrigated terrace agriculture was practiced on slopes, small plateaus, and valleys in the close vicinity of Jawa. Floodwater from nearby wadis or runoff from adjacent slopes was collected and diverted via surface canals. The terraced fields were arranged in cascades, allowing effective water exploitation through a system of risers, canals and spillways. The examined terrace profiles show similar stratigraphic sequences of mixed unstratified fine sediments that are composed of small-scale relocated sediments with local origin. The accumulation of these fines is associated with the construction of agricultural terraces, forcing infiltration and storage of the water within the terraces. Two OSL ages of terrace fills indicate that the construction of these terrace systems started as early as 5300 ± 300 a, which fits well to the beginning of the occupation phase of Jawa at around 3.500 calBC, thus making them to the oldest examples of its kind in the Middle East

  10. Paleoseismological investigations and Geomorphology on the Gaenserndorf Terrace in the central Vienna Basin (Austria) (United States)

    Weissl, Michael; Hintersberger, Esther; Lomax, Johanna; Decker, Kurt


    In the central Vienna Basin normal faults define the eastern and western margins of Pleistocene Danube terraces north of Vienna. The terrace body is built up of coarse sandy gravel and sand. Locally the terrace surface is covered with eolian and alluvial sediments of the last glacial revealing OSL/IRSL ages of about 15-16 ka. High resolution digital terrain models (LIDAR) show relicts of a periglacial landscape in the northern part of the Middle Pleistocene (MIS 8) terrace. Large elongated depressions in the northern parts of the terrace are interpreted as the basins of former thermokarst lakes due to analogies in recent periglacial zones. Draining valleys corrugate the fault scarps indicating advanced subsidence of the Aderklaa and Obersiebenbrunn Quaternary basins before the last Glacial. Obviously the periglacial morphology is only preserved in the elevated parts of the terrace which is located in the footwall of the bounding normal faults. In the hanging wall Quaternary basins are filled with up to 40 m thick Pleistocene and Holocene growth strata. During the last decade three faults were investigated by trenching. In contrast to the earlier trench sites on the Markgrafneusiedl Fault and the Vienna Basin Transform Fault it was not possible to provide clear evidence for offset on the Aderklaa-Bockfliess fault because cryoturbation deformed the covering fluvial sediments together with the underlying Gaenserndorf terrace gravels. However it was possible to localize this fault precisely applying an electrical resistivity tomography. The resulting ERT-section shows an offset of the 200-300 ky old terrace and the underlying Miocene sediments of about 9-10 meters suggesting a vertical slip rate of 0.03 - 0.05 mm/a.

  11. Measurements of rain splash on bench terraces in a humid tropical steepland environment (United States)

    van Dijk, A. I. J. M.; Bruijnzeel, L. A.; Wiegman, S. E.


    Soil loss continues to threaten Java's predominantly bench-terraced volcanic uplands. Sediment transport processes on back-sloping terraces with well-aggregated clay-rich oxisols in West Java were studied using two different techniques. Splash on bare, cropped, or mulched sub-horizontal (2-3°) terrace beds was studied using splash cups of different sizes, whereas transport of sediment on the predominantly bare and steep (30-40/deg ) terrace risers was measured using a novel device combining a Gerlach-type trough with a splash box to enable the separate measurement of transport by wash and splash processes. Measurements were made during two consecutive rainy seasons. The results were interpreted using a recently developed splash distribution theory and related to effective rainfall erosive energy. Splash transportability (i.e. transport per unit contour length and unit erosive energy) on the terrace risers was more than an order of magnitude greater than on bare terrace beds (0·39-0·57 versus 0·013-0·016 g m J-1). This was caused primarily by a greater average splash distance on the short, steep risers (>11 cm versus c. 1 cm on the beds). Splashed amounts were reduced by the gradual formation of a protective pavement of coarser aggregates, in particular on the terrace beds. Soil aggregate size exhibited an inverse relationship with detachability (i.e. detachment per unit area and unit erosive energy) and average splash length, and therefore also with transportability, as did the degree of canopy and mulch cover. On the terrace risers, splash-creep and gravitational processes transported an additional 6-50% of measured rain splash, whereas transport by wash played a marginal role.

  12. Digital data sets that describe aquifer characteristics of the Enid isolated terrace aquifer in northwestern Oklahoma (United States)

    Becker, C.J.; Runkle, D.L.; Rea, Alan


    ARC/INFO export and nonproprietary format files The data sets in this report include digitized aquifer boundaries and maps of hydraulic conductivity, recharge, and ground-water level elevation contours for the Enid isolated terrace aquifer in northwestern Oklahoma. The Enid isolated terrace aquifer covers approximately 82 square miles and supplies water for irrigation, domestic, municipal, and industrial use for the City of Enid and western Garfield County. The Quaternary-age Enid isolated terrace aquifer is composed of terrace deposits that consist of discontinuous layers of clay, sandy clay, sand, and gravel. The aquifer is unconfined and is bounded by the underlying Permian-age Hennessey Group on the east and the Cedar Hills Sandstone Formation of the Permian-age El Reno Group on the west. The Cedar Hills Sandstone Formation fills a channel beneath the thickest section of the Enid isolated terrace aquifer in the midwestern part of the aquifer. All of the data sets were digitized and created from information and maps in a ground-water modeling thesis and report of the Enid isolated terrace aquifer. The maps digitized were published at a scale of 1:62,500. Ground-water flow models are numerical representations that simplify and aggregate natural systems. Models are not unique; different combinations of aquifer characteristics may produce similar results. Therefore, values of hydraulic conductivity and recharge used in the model and presented in this data set are not precise, but are within a reasonable range when compared to independently collected data.

  13. Terrace Agriculture of the Hani People – Cultural Heritage of the South-West China

    Directory of Open Access Journals (Sweden)

    Kladovshchikova Mariya Evgenyevna


    Full Text Available The article presents the features of terrace agriculture of Hani and Yi indigenous minorities, living in the Yunnan province in the South-West China, just a step away from the Laos and Vietnam boundaries. The cultural landscape of the Hani rice terraces, included into the UNESCO World Heritage List in 2013 (Cultural Landscape of Honghe Hani Rice Terraces, expresses the conservation of the minorities’ course of life during the last 1 300 years. The geological framework, climate patterns and conform type of vegetation predefine the specific character of natural conditions necessary for terrace agriculture and red rice growth – the most important crop within the region. At that, the landscape picture which fully reflects the season fluctuations of regional subtropical climate, also facilitates to aesthetic and romantic perception forming, symbolizing man-made environment integral and interlaced into natural landscape. The special focus is made on the description of terraced slopes unique morphology and ancient land cultivation technologies for the essential regional culture – red rice. Preservation of centuries-old traditions of efficient agriculture makes it possible to achieve integration of cultural and natural landscapes, that seamlessly comprises the ethnic minorities’ life, as well as to prevent development of erosion and landslide slope processes. The elements of the traditional Hani people way of life, including ritual customs associated with terrace agriculture, are particularly described.

  14. Spatio-temporal relation between landslide occurrence and abandoned or not maintained agricultural terraces in the Moldavian Plateau, NE Romania (United States)

    Ciprian Margarint, Mihai; Santangelo, Michele; Niculita, Mihai; Bucci, Francesco


    Terraced landscapes are one of the most obvious human-shaped landscapes, mainly used to reduce the negative impact of soil erosion due to uncontrolled runoff and shallow landslides occurrence. Nevertheless, as the recent literature emphasizes, these old best practices can transform into a potential hazard for soil degradation, if not appropriately maintained. In Moldavian Plateau (NE Romania), agricultural terraces were built after the 1960s for landslide, soil erosion and runoff control, mainly in connection with construction of reservoirs, for increasing their operation time. Usually, the slope reduction was obtained by construction of cut-off ditches, hillside ditches, intermittent terraces, bench terraces, broad-based terraces, vineyardand orchard terraces. Due to the dry climatic setting, to the lack of hard rocks for construction, and to the generally light earth moving machinery available for construction, terraces are generally characterized by a small escarpment (0.5m to 1m), and a relatively short lateral extension (5 to 40 m). When the terraces were maintained, the backslope was typically covered with grass. When, after the 1990s, the lands were returned to the initial owners, the vegetation cover of the terraces was no more maintained, and the terraces themselves were progressively abandoned, due to lack of funds. Accurate landslide mapping on high resolution LiDAR DEM derived images, allowed to produce geomorphological inventories in 5 test cases, representative of the whole study area. In each inventory, landslides were classified based on type and relative age based on published classification schemes. We investigate the spatial and temporal relation between landslides occurrence and terraces, based on the spatial interactions of landslides of different ages and terraces. Results reveal that terraces were built, both on landslide-free and landslide-bearing slopes, and that frequently landslides and gullies develop on terraced slopes. Reactivations of

  15. Spatial and temporal variations in denudation rates derived from cosmogenic nuclides in four European fluvial terrace sequences (United States)

    Schaller, M.; Ehlers, T. A.; Stor, T.; Torrent, J.; Lobato, L.; Christl, M.; Vockenhuber, C.


    The denudation of landscapes is affected by temporal and spatial variations in tectonics, climate, and vegetation. However, deciphering the contributions of these different processes has proven challenging. In this study, cosmogenic nuclide-derived modern and paleo catchment-wide denudation rates in four European rivers are investigated. We present 12 new and 4 recalculated cosmogenic nuclide-derived denudation rates from modern river sediments and 14 paleo-denudation rates from terraces deposited over the last 2 Ma. The catchments studied are located in regions with minimal Quaternary tectonic activity and span different climates over 12o latitude. Results indicate that modern denudation rates range between 16 ± 11 and 51 ± 7 mm/ka with no clear latitudinal variation. Modern denudation rates are compared with catchment geomorphic indices including slope, fluvial steepness index, and relief. The denudation rates correlate better to catchment topographic indices (R2 ≈ 0.4) rather than climate. Paleo-denudation rates range from 8 ± 7 to 56 ± 7 mm/ka and are associated with a possible increase in the average paleo-denudation rates over the past 2 Ma. Taken together, the results indicate that quantification of catchment-wide denudation rates over long (Quaternary) time scales because of climate change is difficult. Future work to study climate influence on denudation rates should focus on the successes of previous work that document transient denudation rates over shorter and more recent time scales, i.e., from the Last Glacial Maximum to present.

  16. Integrating Geomorphic and Social Dynamics in the Analysis of Anthropogenic Landforms: Examining Landscape Evolution of Terrain Modified by Agricultural Terracing (United States)

    Glaubius, J.; Maerker, M.


    Anthropogenic landforms, such as mines and agricultural terraces, are impacted by both geomorphic and social processes at varying intensities through time. In the case of agricultural terraces, decisions regarding terrace maintenance are intertwined with land use, such as when terraced fields are abandoned. Furthermore, terrace maintenance and land use decisions, either jointly or separately, may be in response to geomorphic processes, as well as geomorphic feedbacks. Previous studies of these complex geomorphic systems considered agricultural terraces as static features or analyzed only the geomorphic response to landowner decisions. Such research is appropriate for short-term or binary landscape scenarios (e.g. the impact of maintained vs. abandoned terraces), but the complexities inherent in these socio-natural systems requires an approach that includes both social and geomorphic processes. This project analyzes feedbacks and emergent properties in terraced systems by implementing a coupled landscape evolution model (LEM) and agent-based model (ABM) using the Landlab and Mesa modeling libraries. In the ABM portion of the model, agricultural terraces are conceptualized using a life-cycle stages schema and implemented using Markov Decision Processes to simulate the changing geomorphic impact of terracing based on human decisions. This paper examines the applicability of this approach by comparing results from a LEM-only model against the coupled LEM-ABM model for a terraced region. Model results are compared by quantify and spatial patterning of sediment transport. This approach fully captures long-term landscape evolution of terraced terrain that is otherwise lost when the life-cycle of terraces is not considered. The coupled LEM-ABM approach balances both environmental and social processes so that the socio-natural feedbacks in such anthropogenic systems can be disentangled.

  17. Effects of Terracing and Agroforestry on Soil and Water Loss in Hilly Areas of the Sichuan Basin, China

    Institute of Scientific and Technical Information of China (English)

    J.H. ZHANG; Z.A. SU; G.C. LIU


    Soil erosion in hilly areas of the Sichuan Basin is a serious concern over sustainable crop production and sound ecosystem. A 3-year experiment was conducted using the method of runoff plots to examine the effects of terracing and agroforestry in farmland systems on soil and water conservation of slope fields m the hilly areas in Jianyang County, Sichuan Province, Southwestern China. A power function (Y = aXb) can statistically describe the relationship between water runoff (Y) and rainfall (X). The regression equation for the treatment of sloping terraces with crops (Plot 2) is remarkably different from that for the treatment of sloping terraces with grasses and trees (Plot 1) and the conventional up- and down-slope crop system (Plot 3) regarding equation coefficients, while regression equations are similar between Plot 1 and Plot 3. Water runoff amount and runoff coefficient of slope fields increased by 21.5~41.0 % and 27.5 ~ 69.7 % respectively, compared to those of sloping terraces, suggesting that terracing notably reduced the water runoff in the field. In the case of sloping terraces, lower amount of water runoff was observed on sloping terraces with crops than on sloping terraces with grasses and trees. Sediment yields on the slope fields in the normal year of rainfall distribution were notably higher (34.41 ~ 331.67 % and 37.06 ~ 403.44 % for Plot 1 and Plot 2, respectively) than those on sloping terraces, implying that terracing also plays a significant role in the reduction in soil erosion. It is suggested that terracing with crops is significantly effective for soil and water conservation in cultivated farmland,while the conventional practice of up-and down-slope cultivation creates high rates of water runoff and soil sediment transport.Terracing with grasses and fruit trees shows a less reduction in water runoff than terracing with crops,which was observed in the 3-year experiments.

  18. Structured heterogeneity in a marine terrace chronosequence: Upland mottling (United States)

    Schulz, Marjorie S.; Stonestrom, David A.; Lawrence, Corey R.; Bullen, Thomas D.; Fitzpatrick, John; Kyker-Snowman, Emily; Manning, Jane; Mnich, Meagan


    Soil mottles generally are interpreted as a product of reducing conditions during periods of water saturation. The upland soils of the Santa Cruz, CA, marine terrace chronosequence display an evolving sequence of reticulate mottling from the youngest soil (65 ka) without mottles to the oldest soil (225 ka) with well-developed mottles. The mottles consist of an interconnected network of clay and C-enriched regions (gray, 2.5Y 6/1) bordered by leached parent material (white, 2.5Y 8/1) within a diminishing matrix of oxidized parent material (orange, 7.5YR 5/8). The mottles develop in soils that formed from relatively uniform nearshore sediments and occur below the depth of soil bioturbation. To explore how a presumably wetland feature occurs in an unsaturated upland soil, physical and chemical characteristics of mottle separates (orange, gray, and white) were compared through the deep time represented by the soil chronosequence. Mineralogical, isotopic, and surface-area differences among mottle separates indicate that rhizogenic centimeter-scale mass transfer acting across millennia is an integral part of weathering, pedogenesis, and C and nutrient transfer. Elemental analysis, electron microscopy, and Fe-isotope systematics indicate that mottle development is driven by deep roots together with their fungal and microbial symbionts. Taken together, these data suggest that deep soil horizons on old stable landforms can develop reticulate mottling as the long-term imprint of rhizospheric processes. The processes of rhizogenic mottle formation appear to regulate pedogenesis, nutrients, and C sequestration at depth in unsaturated zones.

  19. Terrace Geochemistry at the Shiprock, New Mexico, Disposal Site - WM2017-17232 Initial Phase

    Energy Technology Data Exchange (ETDEWEB)

    Kautsky, Mark [USDOE Office of Legacy Management, Washington, DC (United States); Ranalli, Tony [Navarro Research and Engineering, Oak Ridge, TN (United States); Dander, David [Navarro Research and Engineering, Oak Ridge, TN (United States); Miller, David [Navarro Research and Engineering, Oak Ridge, TN (United States)


    The objective of this investigation was to identify and differentiate potential non- mill-related water inputs to a shallow terrace groundwater system through the use of aqueous chemical and isotopic tracers at a former uranium- and vanadium-ore processing facility. Terrace groundwater in the vicinity of the Shiprock, New Mexico, site is hypothesized to be largely anthropogenic because natural rates of recharge in the terrace are likely insufficient to sustain a continuous water table in the terrace alluvial system, as observed in several analogue terrace locations east of the site and in response to post-mill dewatering efforts across the site. The terrace is composed of alluvial sand and gravel and weathered and unweathered Mancos Shale. Terrace groundwater exists and flows in the alluvium and to a much less extent in the Mancos Shale. Historical data established that in both the terrace and floodplain below the terrace, mill-derived uranium and sulfate is found primarily in the alluvium and the upper portion of the weathered Mancos Shale. Groundwater extraction is being conducted in the vicinity of former mill operations and in washes and seeps to dewater the formation and remove contamination, thus eliminating these exposure pathways and minimizing movement to the floodplain. However, past and present contribution of non-mill anthropogenic water sources may be hindering the dewatering effort, resulting in reduced remedy effectiveness. Groundwater source signatures can be determined based on chemical and isotopic ratios and are used to help identify and delineate both mill and non-mill water contributions. Aqueous chemical and isotopic tracers, such as 234U/238U activity ratios and uranium concentrations, δ34S sulfate and sulfate concentrations, tritium concentrations, and δ2Hwater and δ18O water are being used in this Phase I study. The aqueous chemical and isotopic analysis has identified areas on the terrace where groundwater is derived from mill

  20. Agronomic Challenges and Opportunities for Smallholder Terrace Agriculture in Developing Countries (United States)

    Chapagain, Tejendra; Raizada, Manish N.


    Improving land productivity is essential to meet increasing food and forage demands in hillside and mountain communities. Tens of millions of smallholder terrace farmers in Asia, Africa, and Latin America who earn $1–2 per day do not have access to peer-reviewed knowledge of best agronomic practices, though they have considerable traditional ecological knowledge. Terrace farmers also lack access to affordable farm tools and inputs required to increase crop yields. The objectives of this review are to highlight the agronomic challenges of terrace farming, and offer innovative, low-cost solutions to intensify terrace agriculture while improving local livelihoods. The article focuses on smallholder farmers in developing nations, with particular reference to Nepal. The challenges of terrace agriculture in these regions include lack of quality land area for agriculture, erosion and loss of soil fertility, low yield, poor access to agricultural inputs and services, lack of mechanization, labor shortages, poverty, and illiteracy. Agronomic strategies that could help address these concerns include intensification of terraces using agro-ecological approaches along with introduction of light-weight, low-cost, and purchasable tools and affordable inputs that enhance productivity and reduce female drudgery. To package, deliver, and share these technologies with remote hillside communities, effective scaling up models are required. One opportunity to enable distribution of these products could be to “piggy-back” onto pre-existing snackfood/cigarette/alcohol distribution networks that are prevalent even in the most remote mountainous regions of the world. Such strategies, practices, and tools could be supported by formalized government policies dedicated to the well-being of terrace farmers and ecosystems, to maintain resiliency at a time of alarming climate change. We hope this review will inform governments, non-governmental organizations, and the private sector to draw

  1. The importance of understanding landscape evolution in studies of terraced agriculture (United States)

    Ferro-Vazquez, Cruz; Lang, Carol; Kaal, Joeri; Stump, Daryl


    Before the invention of modern, large-scale engineering projects, terrace systems were rarely built in single phases of construction, but instead developed gradually, and could even be said to have evolved. Understanding this process of landscape change is therefore important in order to fully appreciate how terrace systems were built and functioned, and is also pivotal to understand how the communities that farmed these systems responded to changes; whether these are changes to the landscape brought about by the farming practices themselves, or changes to social, economic or climatic conditions. With this aim, we studied the historic and extensive terraced landscape at Konso, southwest Ethiopia, combining archaeological stratigraphy, soil micromorphology and geochemistry. Our results demonstrated that erosion has not only been the trigger for the inception of the Konso terraced system but also the foundation of its productivity: it was engineered for taking advantage of erosion by controlling it, first by harvesting soils that had washed into watercourses within irrigable riverside sediment traps, and then by effectively 'repopulating' the denuded hillsides with new soils through the construction of hillside terraces. From this new perspective, soil erosion has been a necessary enemy which, while managed, has constituted an agronomic resource, the system having initially relied on soil erosion to be productive, and the community having apparently only begun constructing terraces in order to protect the productive alluvial fields that were the legacy of that first phase of erosion. Research that takes into account how terrace systems change through time can thus provide important details of whether the function of the system has changed, and can help assess how the legacies of former practices impact current or future cultivation.

  2. Late Quaternary tectonic landforms and fluvial aggradation in the Saryu River valley: Central Kumaun Himalaya (United States)

    Kothyari, Girish Ch.; Luirei, Khayingshing


    The present study has been carried out with special emphasis on the aggradational landforms to explain the spatial and temporal variability in phases of aggradation/incision in response to tectonic activity during the late Quaternary in the Saryu River valley in central Kumaun Himalaya. The valley has preserved cut-and-fill terraces with thick alluvial cover, debris flow terraces, and bedrock strath terraces that provide signatures of tectonic activity and climate. Morphostratigraphy of the terraces reveals that the oldest landforms preserved south of the Main Central Thrust, the fluvial modified debris flow terraces, were developed between 30 and 45 ka. The major phase of valley fill is dated between 14 and 22 ka. The youngest phase of aggradation is dated at early and mid-Holocene (9-3 ka). Following this, several phases of accelerated incision/erosion owing to an increase in uplift rate occurred, as evident from the strath terraces. Seven major phases of bedrock incision/uplift have been estimated during 44 ka (3.34 mm/year), 35 ka (1.84 mm/year), 15 ka (0.91 mm/year), 14 ka (0.83 mm/year), 9 ka (1.75 mm/year), 7 ka (5.38 mm/year), and around 3 ka (4.4 mm/year) from the strath terraces near major thrusts. We postulate that between 9 and 3 ka the terrain witnessed relatively enhanced surface uplift (2-5 mm/year).

  3. Isochron burial dating of the Haslau terrace of the Danube (Vienna Basin) and interlaboratory comparison of sample preparation in Vienna and Budapest (United States)

    Ruszkiczay-Rüdiger, Zsófia; Neuhuber, Stephanie; Decker, Kurt; Braucher, Régis; Fiebig, Marcus; Braun, Mihály; Lachner, Johannes; Aster Team


    In the Vienna Basin, terraces to the South of the Danube form a staircase with altitudes ranging between 25 and 130 m above current water level. The terrace system has been strongly dissected by faults related to the sinistral movement of the Vienna Basin Transform Fault System [1, 2]. Although each fault block displays a slightly different succession of terraces, fault-related vertical displacements south of the Danube have not yet been quantified. To better understand the Quaternary terrace sequence and its displacement along a fault segment south of the Danube, the isochron burial dating method [3] based on the 26Al and 10Be cosmogenic nuclide pair has been used on a terrace at Haslau an der Donau (˜40 m above river level). This terrace is locally the lowest of a staircase of a total of 6 different levels. Based on geomorphological mapping, its age was considered to be Middle Pleistocene [4]. The sample set consisted of several quartzite cobbles taken from two sedimentary units (5.5 m and 11.8 m depth) separated by an erosional hiatus of unknown duration. Six cobbles were selected for inter-laboratory comparison and processed at both the Cosmogenic Nuclide Sample Preparation Laboratory at Vienna and at Budapest [5]. AMS measurements were performed at the French national facility ASTER (CEREGE, Aix-en-Provence) and at the Vienna Environmental Research Accelerator (VERA). Initially, the obtained results show that the 10Be and 26Al concentrations calculated from the subsamples processed independently using different extraction schemes at both laboratories overlap within error for all subsamples but one, whose 26Al concentrations were significantly different. The low 26Al concentration measured in one Budapest sample probably resulted from Al having been trapped within the insoluble residues observed after evaporation to dryness. A modification of the sample processing allows overcoming this difficulty while treating for the following sample set. The results

  4. High-resolution Pleiades DEMs and improved mapping methods for the E-Corinth marine terraces (United States)

    de Gelder, Giovanni; Fernández-Blanco, David; Delorme, Arthur; Jara-Muñoz, Julius; Melnick, Daniel; Lacassin, Robin; Armijo, Rolando


    The newest generation of satellite imagery provides exciting new possibilities for highly detailed mapping, with ground resolution of sub-metric pixels and absolute accuracy within a few meters. This opens new venues for the analysis of geologic and geomorphic landscape features, especially since photogrammetric methods allow the extraction of detailed topographic information from these satellite images. We used tri-stereo imagery from the Pleiades platform of the CNES in combination with Euclidium software for image orientation, and Micmac software for dense matching, to develop state-of-the-art, 2m-resolution digital elevation models (DEMs) for eight areas in Greece. Here, we present our mapping results for an area in the eastern Gulf of Corinth, which contains one of the most extensive and well-preserved flights of marine terraces world-wide. The spatial extent of the terraces has been determined by an iterative combination of an automated surface classification model for terrain slope and roughness, and qualitative assessment of satellite imagery, DEM hillshade maps, slope maps, as well as detailed topographic analyses of profiles and contours. We determined marine terrace shoreline angles by means of swath profiles that run perpendicularly to the paleo-seacliffs, using the graphical interface TerraceM. Our analysis provided us with a minimum and maximum estimate of the paleoshoreline location on ~750 swath profiles, by using the present-day cliff slope as an approximation for its paleo-cliff counterpart. After correlating the marine terraces laterally we obtained 16 different terrace-levels, recording Quaternary sea-level highstands of both major interglacial and several interstadial periods. Our high-resolution Pleiades-DEMs and improved method for paleoshoreline determination allowed us to produce a marine terrace map of unprecedented detail, containing more terrace sub-levels than hitherto. Our mapping demonstrates that we are no longer limited by the

  5. Physical parameters of Fluvisols on flooded and non-flooded terraces (United States)

    Kercheva, Milena; Sokołowska, Zofia; Hajnos, Mieczysław; Skic, Kamil; Shishkov, Toma


    The heterogeneity of soil physical properties of Fluvisols, lack of large pristine areas, and different moisture regimes on non-flooded and flooded terraces impede the possibility to find a soil profile which can serve as a baseline for estimating the impact of natural or anthropogenic factors on soil evolution. The aim of this study is to compare the pore size distribution of pristine Fluvisols on flooded and non-flooded terraces using the method of the soil water retention curve, mercury intrusion porosimetry, nitrogen adsorption isotherms, and water vapour sorption. The pore size distribution of humic horizons of pristine Fluvisols on the non-flooded terrace differs from pore size distribution of Fluvisols on the flooded terrace. The peaks of textural and structural pores are higher in the humic horizons under more humid conditions. The structural characteristics of subsoil horizons depend on soil texture and evolution stage. The peaks of textural pores at about 1 mm diminish with lowering of the soil organic content. Structureless horizons are characterized by uni-modal pore size distribution. Although the content of structural pores of the subsoil horizons of Fluvisols on the non-flooded terrace is low, these pores are represented by biopores, as the coefficient of filtration is moderately high. The difference between non-flooded and flooded profiles is well expressed by the available water storage, volume and mean radius of pores, obtained by mercury intrusion porosimetry and water desorption, which are higher in the surface horizons of frequently flooded Fluvisols.

  6. Comparison of up ladder type and terraced type normalizing heat treatments of heavy cylinder

    Institute of Scientific and Technical Information of China (English)

    孙建亮; 彭艳; 邱丑武; 张永振


    Because of the mixed grain and coarse grain structure, the long heat treatment cycle and large energy conservation in the heavy cylinder heat treatment process, the up ladder type and terraced type normalizing heat treatment of heavy cylinder after rolling were put forward. The microstructure and mechanical properties of 2.25Cr1Mo0.25V steel after the up ladder type normalizing, terraced type normalizing and isothermal type normalizing were studied. Experimental results show that: 1) For the grain refinement, the twice terraced type normalizing is better than the up ladder type and isothermal type normalizing, and the average grain size is 18μm; 2) The yield strength, tensile strength and−30 °C charpy impact energy after twice terraced type normalizing are 681 MPa, 768 MPa and 181 J, respectively, and the mechanical properties are better than those of the up ladder type and isothermal type normalizing; 3) Compared with the isothermal type normalizing, the holding time of terraced type normalizing can be shortened by 30%, which greatly reduces the energy consumption.

  7. Sustainability of terraced paddy fields in traditional satoyama landscapes of Japan. (United States)

    Fukamachi, Katsue


    Terraced paddy fields are essential components of the traditional cultural landscape of Japan, the satoyama landscape. They have been sustainably cultivated in a variety of ecological and social environments through time, and are highly valued as local resources with multiple functions. This paper reviews the recent nationwide movement for conservation of satoyama landscapes and shows that over the last decades, the government has increasingly created policies based on national regulation or international frameworks that concern the culture and environment in rural areas. Recent measures for the sustainability of terraced paddy fields do not only focus on rice terraces, but are directed at each satoyama landscape as a whole under careful consideration of how landscape elements are connected while taking into account the unique features of each area. Nevertheless, it has become difficult to ensure the continued use and maintenance of terraced rice paddies both in depopulated and suburban satoyama landscapes. The motivation for conserving satoyama landscapes, including those with terraced rice paddies, can be found in the awareness and appreciation of the unique characteristics of each locality that offer opportunities that can only be experienced in that particular area. A satoyama landscape that offers such opportunities allows continuity of traditional practices while integrating necessary changes.

  8. Physical data of soil profiles formed on late Quaternary marine terraces near Santa Cruz, California (United States)

    Munster, Jennie; Harden, Jennifer W.


    The marine terraces in and around Santa Cruz, California, represent a set of well-preserved terraces formed as a product of geology, sea level, and climate. A marine terrace begins as a wave cut platform. Eustatic sea level changes, seacliff erosion, and tectonic uplift work together to generate marine terraces. "When a wave-cut platform is raised (due to tectonic activity) above sea level and cliffed by wave action it becomes a marine terrace" (Bradley, 1957, p. 424). During glacial periods, eustatic sea level is estimated to have dropped by 150 meters (Fairbanks, 1989). Cliff retreat measured from aerial photographs between 1930 and 1980 vary from 0.0 to 0.2 m yr–1 (Best and Griggs, 1991). Estimates of uplift rates along the Santa Cruz coastline vary from 0.10 to 0.48 m kyr–1 (Bradley and Griggs, 1976; Weber and others, 1999). Uplift mechanisms include coseismic uplift associated both with a reverse component of slip on the steeply SW dipping Loma Prieta fault in the restraining bend of the San Andreas Fault and a small component of reverse slip on the steeply SE dipping San Gregorio fault (Anderson and Menking 1994). Previous work studying physical properties on these terraces include Pinney and others (in press) and Aniku (1986) and Bowman and Estrada (1980). Sedimentary deposits of the marine terraces are a mixture of terrestrial and marine sediments but generally consist of a sheet of marine deposits overlying the old platform and a wedge of nonmarine deposits banked against the old sea cliff (Bradley, 1957). Bedrock underlying the terraces in the Santa Cruz area is generally either Santa Margarita Sandstone or Santa Cruz Mudstone. The Santa Margarita Sandstone represents an upper Miocene, transgressive, tidally dominated marine-shelf deposit with crossbedded sets of sand and gravel and horizontally stratified and bioturbated invertebrate-fossils beds (Phillips, 1990). The siliceous Santa Cruz Mudstone, of late Miocene age, conformably overlies the Santa

  9. The Early Pleistocene development of the Gediz River, Western Turkey: An uplift-driven, climate-controlled system?

    NARCIS (Netherlands)

    Maddy, D.; Demir, T.; Bridgland, D.R.; Veldkamp, A.; Stemerdink, C.; Schriek, van der T.; Westaway, R.


    This paper reports the latest details from an on-going investigation of the Early Pleistocene buried river terrace sequence of the Gediz River 40 km upstream of the Ala¿ehir graben in the Kula volcanic province, Western Turkey. Using clast lithology to characterise sediment provenance, we demonstrat

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

    Directory of Open Access Journals (Sweden)

    Sutikno .


    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.

  11. Analysis of the Terraced Construction Effect on Ecological  Economic Coordinated Development in the Southwest China

    Directory of Open Access Journals (Sweden)

    Ping Liang


    Full Text Available This paper through the correlation analysis and efficiency analysis, studied the differences between slope croplands and terraces on soil, water and fertilizer conservation in Southwest China. Meanwhile, it carried out a quantum chemical calculation of the ecological, economic and social benefits brought to the local Hani residents by terrace construction and concluded that terraced fields can promote the mutual coordination effect of water and fertilizer. Thus, it is beneficial for crop growth and development and increase grain output, to achieve the purpose of efficient water use and stable high yield. The results show that with the improvement of Hani ecological environment and the increase of land utilization, local ecological, economic and social benefits are significantly increased, which has laid a solid foundation for the agricultural industrialization development and implementation of sustainable agricultural development strategy in Hani. And also, it provides guarantee for the ecological, economic and social coordinated development of the county.

  12. Ancient agricultural terraces in the Kislovodsk Depression: History and modern state of the soils (United States)

    Borisov, A. V.; Korobov, D. S.; Simakova, A. N.; Zanina, O. G.; Bukhonov, A. V.; Demidov, V. V.


    The results of the investigation into the history of soilscapes in the Kislovodsk Depression are discussed. It is shown that up to 60-70% of the area of slopes and interfluvial plateaus at the heights of 900-1500 m a.s.l. was terraced in the Late Bronze-Early Iron ages, during the Kobansk cultural stage (1200-600 BC). Under these conditions, a sharp change in the climate with a considerable increase in the annual precipitation in the middle of the first millennium BC resulted in the activation of erosion and the formation of a layer of colluvial sediments overlying the buried soil on the terraces. Thus, the middle of the first millennium BC can be considered the zero moment for the modern stage of soil formation in the region. Problems of the current state of the terrace complexes and the development of erosion on them are also discussed.

  13. Terrace width distribution during unstable homoepitaxial growth of GaAs(110): An experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Crespillo, M.L. [Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC), Sor Juana Ines de la Cruz s/n, Cantoblanco, 28049 Madrid (Spain)]. E-mail:; Sacedon, J.L. [Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC), Sor Juana Ines de la Cruz s/n, Cantoblanco, 28049 Madrid (Spain); Tejedor, P. [Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC), Sor Juana Ines de la Cruz s/n, Cantoblanco, 28049 Madrid (Spain)


    The temporal evolution of the step bunching instability formed during GaAs homoepitaxial growth on the GaAs(110) vicinal to (111)A has been studied by atomic force microscopy (AFM) and the step-step distribution has been quantified as a function of deposition time. Analysis of the AFM data has shown that neither the terrace width distribution (TWD) nor the terrace height distribution (THD) fit to a Gaussian function in the initial stages of growth, but both evolve with time as the bunching instability develops. After deposition of 500 ML of GaAs the TWD exhibits a clear Gaussian behavior while the THD is very well fitted to a Lorentzian distribution. The GaAs surface morphology initially shows a great dispersion in terrace height and width values with a clear anisotropy along the <001> tilt direction, but evidence of self-controlled growth is observed irrespective of layer thickness.

  14. A long-term rock uplift rate for eastern Crete from exposure dating of marine terraces (United States)

    Strobl, M.; Hetzel, R.; Ivy-Ochs, S.; Alfimov, V.; Kubik, P. W.; Fassoulas, C.; Palumbo, L.


    The island of Crete in the forearc of the Hellenic subduction zone has a rugged topography with a relief exceeding 2 km. Rock uplift rates of 2-4 mm/a were estimated previously from raised Late Holocene shorelines (Lambeck, 1995) but may not be representative on longer timescales, because earthquakes with up to 9 m of coseismic uplift have recently affected Crete (Stiros, 2001). Here we use marine terraces near Kato Zakros to quantify the long-term rock uplift rate for eastern Crete. Our field investigations and topographic profiles document a flight of at least 15 marine bedrock terraces carved into limestone bedrock. Age constraints for the terraces were obtained by 36Cl exposure dating of bedrock samples and 10Be dating of sandstone cobbles found on some terraces. Our results suggest that the terraces T4 and T5 at elevations of 68 and 76 m, respectively, formed during sea level highstands associated with marine isotope stage 5e, i.e. ~125 ka ago. Correlating the other terraces (T1 to T11) to a sea-level curve for the Red Sea (Siddall et al., 2003) indicates an uplift rate of 0.5-0.6 mm/a during the last 400 ka; significantly lower than previous estimates based on the elevation of Late Holocene shorelines. References Lambeck, K. (1995), Late Pleistocene and Holocene sea-level change in Greece and SW Turkey - a separation of eustatic, isostatic and tectonic contributions. Geophys. J. Int. 122, 1022-1044. Siddall, M., Rohling, E.J., Almogi-Labin, A., Hemleben, C., Meischner, D., Schmelzer, I., and Smeed, D.A. (2003), Sea-level fluctuations during the last glacial cycle. Nature, 423, 853-858. Stiros, S.C. (2001), The AD 365 Crete earthquake and possible seismic clustering during the fourth to sixth centuries AD in the Eastern Mediterranean: a review of historical and archaeological data. J. Struct. Geol., 23, 545-562.

  15. Geomorphometric delineation of floodplains and terraces from objectively defined topographic thresholds

    Directory of Open Access Journals (Sweden)

    F. J. Clubb


    Full Text Available Floodplain and terrace features can provide information about current and past fluvial processes, including channel response to varying discharge and sediment flux, sediment storage, and the climatic or tectonic history of a catchment. Previous methods of identifying floodplain and terraces from digital elevation models (DEMs tend to be semi-automated, requiring the input of independent datasets or manual editing by the user. In this study we present a new method of identifying floodplain and terrace features based on two thresholds: local gradient, and elevation compared to the nearest channel. These thresholds are calculated statistically from the DEM using quantile–quantile plots and do not need to be set manually for each landscape in question. We test our method against field-mapped floodplain initiation points, published flood hazard maps, and digitised terrace surfaces from seven field sites from the US and one field site from the UK. For each site, we use high-resolution DEMs derived from light detection and ranging (lidar where available, as well as coarser resolution national datasets to test the sensitivity of our method to grid resolution. We find that our method is successful in extracting floodplain and terrace features compared to the field-mapped data from the range of landscapes and grid resolutions tested. The method is most accurate in areas where there is a contrast in slope and elevation between the feature of interest and the surrounding landscape, such as confined valley settings. Our method provides a new tool for rapidly and objectively identifying floodplain and terrace features on a landscape scale, with applications including flood risk mapping, reconstruction of landscape evolution, and quantification of sediment storage and routing.

  16. Geomorphometric delineation of floodplains and terraces from objectively defined topographic thresholds (United States)

    Clubb, Fiona J.; Mudd, Simon M.; Milodowski, David T.; Valters, Declan A.; Slater, Louise J.; Hurst, Martin D.; Limaye, Ajay B.


    Floodplain and terrace features can provide information about current and past fluvial processes, including channel response to varying discharge and sediment flux, sediment storage, and the climatic or tectonic history of a catchment. Previous methods of identifying floodplain and terraces from digital elevation models (DEMs) tend to be semi-automated, requiring the input of independent datasets or manual editing by the user. In this study we present a new method of identifying floodplain and terrace features based on two thresholds: local gradient, and elevation compared to the nearest channel. These thresholds are calculated statistically from the DEM using quantile-quantile plots and do not need to be set manually for each landscape in question. We test our method against field-mapped floodplain initiation points, published flood hazard maps, and digitised terrace surfaces from seven field sites from the US and one field site from the UK. For each site, we use high-resolution DEMs derived from light detection and ranging (lidar) where available, as well as coarser resolution national datasets to test the sensitivity of our method to grid resolution. We find that our method is successful in extracting floodplain and terrace features compared to the field-mapped data from the range of landscapes and grid resolutions tested. The method is most accurate in areas where there is a contrast in slope and elevation between the feature of interest and the surrounding landscape, such as confined valley settings. Our method provides a new tool for rapidly and objectively identifying floodplain and terrace features on a landscape scale, with applications including flood risk mapping, reconstruction of landscape evolution, and quantification of sediment storage and routing.

  17. The Dynamic Change and Trend of Groundwater Level in Jinan Yellow River Irrigation Region More Than Twenty Years%济南引黄灌区近20年地下水位动态变化及趋势分析

    Institute of Scientific and Technical Information of China (English)

    徐淑波; 徐立荣; 梅泽本


    利用多年观测资料,对济南引黄灌区地下水位动态变化特征及趋势进行了分析,结果表明:①近二十年济南引黄灌区地下水位年际变化趋势主要受引黄灌溉水量的影响,2002-2013年来地下水位波动下降明显;多年月均地下水位变化出现两个峰值,主峰值主要受汛期降水的影响,次峰值主要受春季引黄灌溉的影响。②对地下水位多年序列和季节序列进行M -K趋势和参数特征分析表明,灌区2000年以后地下水位呈下降趋势,且在2012年以后下降趋势较显著;春季和夏季地下水位总体上无明显趋势,而秋季和冬季分别在2003年和2006年以后呈现较明显的下降趋势。③由于秋季灌区引黄供水远远不能满足实际需水量,为缓解地下水位下降,应适当增加秋季引黄量。%Based on the observational data of many years ,the Mann-Kendall trend test method was adopted to analyze the dynamic change and trend of groundwater level in Jinan Yellow River Irrigation Region .The results indicate that :The trend of annual varia‐tion of groundwater level was mainly affected by irrigation water in irrigation area of Jinan in recent twenty years ,the fluctuation of groundwater level decreased significantly from 2002 to 2013 ;monthly groundwater level has two peaks ,the primary peak mainly af‐fected by the precipitation of flood season and the secondary peak by water supply from the Yellow River in spring .Mann-Kendall trend test of annual and seasonal groundwater level showed that groundwater level declined from 2000 to 2013 ,significantly after 2012 .The rising trend of groundwater level both in spring and summer is not significant ,while significant declining trend of ground‐water level in autumn and in winter can be found after 2003 and 2006 respectively .In autumn drawing groundwater leads to falling of water table as a result of inadequate water supply from the Yellow River for

  18. Twenty-first century vaccines (United States)

    Rappuoli, Rino


    In the twentieth century, vaccination has been possibly the greatest revolution in health. Together with hygiene and antibiotics, vaccination led to the elimination of many childhood infectious diseases and contributed to the increase in disability-free life expectancy that in Western societies rose from 50 to 78–85 years (Crimmins, E. M. & Finch, C. E. 2006 Proc. Natl Acad. Sci. USA 103, 498–503; Kirkwood, T. B. 2008 Nat. Med 10, 1177–1185). In the twenty-first century, vaccination will be expected to eliminate the remaining childhood infectious diseases, such as meningococcal meningitis, respiratory syncytial virus, group A streptococcus, and will address the health challenges of this century such as those associated with ageing, antibiotic resistance, emerging infectious diseases and poverty. However, for this to happen, we need to increase the public trust in vaccination so that vaccines can be perceived as the best insurance against most diseases across all ages. PMID:21893537

  19. Human-Environment System Boundaries: A Case Study of the Honghe Hani Rice Terraces as a World Heritage Cultural Landscape

    Directory of Open Access Journals (Sweden)

    Honglian Hua


    Full Text Available Any World Heritage Cultural Landscape requires a clear boundary for administration. One of the administrative goals is sustainability. There is no widely identified way to demarcate the boundary of a World Heritage Cultural Landscape. This paper aims to explore a methodology framework to provide a holistic perspective for demarcating boundaries for a World Heritage Cultural Landscape. Honghe Hani Rice Terraces (HHRT in Yunnan Province is a new World Heritage Cultural Landscape in China. We use it as a research area to illustrate the methodology framework. The framework of methodology is constructed based on four scales of a human-environment system identified by Anne Buttimer. It is used to describe the level of the sustainability of local economy, social organization, natural environment and people’s understanding of the human-environment. Four types of boundaries were investigated in this area. They are the boundary of Malizhai River Basin, the boundary of local water-allocation organization, the boundary of the economic network and the perceptual boundary of the human-environment system. With a comprehensive perspective, we integrated the four types of boundaries to judge the boundary of the core area of HHRT by three criteria, they are: Environmental sustainability, social justice, and the ability to create a new human-environment system. We conclude that some parts of the boundary of the core area of HHRT do not fit the criteria of sustainable development.

  20. Modification of the potential production capabilities of agricultural terrace soils due to historical cultivation in the Budina cadastral area, Slovakia

    Directory of Open Access Journals (Sweden)

    Slámová Martina


    Full Text Available The soil production attributes of historical agrarian terraced fields were examined in the Budina cadastral area of the Ostrozky Mountains. This landscape represents a unique sub-mountainous Carpathian landscape with farms that use a historically preserved triple-field agricultural system. We determined the geo-spatial parameters of different types of land cover and terraces using geographic information systems. The soil depth was measured in the field, and the skeleton content was determined in the laboratory. We compared data regarding the potential production capabilities of the soil with data from the national classification of agricultural soils. Our results indicated that the soil productivity attributes improved because the naturally less fertile cambisols were positively affected by terracing and long-term cultivation. We recommend the preservation of traditional agricultural activities in historical terraced fields because these terraces represent valuable features that improve the quality of the landscape.

  1. History of the great Kanto earthquakes inferred from the ages of Holocene marine terraces revealed by a comprehensive drilling survey (United States)

    Komori, Junki; Shishikura, Masanobu; Ando, Ryosuke; Yokoyama, Yusuke; Miyairi, Yosuke


    We measured the emergence ages of four marine terraces in the Chikura lowland, which lies to the southeast of the Boso Peninsula, in eastern Japan, to reevaluate the history of the great earthquake occurrences along the Sagami Trough over the past 10,000 years. The dates of the marine terraces are measured via radiocarbon dating of shell fossils obtained from the marine deposits. The sampling method employed in this study collects core samples using a dense and systematic drilling survey, which increased the reliability when correlating shell fossils with marine terraces. In addition, radiocarbon dating was performed with accelerator mass spectrometry, which produces more highly accurate measurements than those measured in previous studies. Moreover, we explored the surface profiles of the terraces with detailed digital elevation model (DEM) data obtained using LiDAR. The maximum emergence ages of the marine terraces were dated at 6300 cal yBP, 3000 cal yBP, and 2200 cal yBP from the top terrace excepting the lowest terrace (which was estimated at AD1703). In addition, another previously unrecognized terrace was detected between the highest and the second terrace in both the dating and the geomorphological analyses and was dated at 5800 cal yBP. The newly obtained ages are nearly a thousand of years younger than previously estimated ages; consequently, the intervals of the great earthquakes that occurred along the Sagami Trough are estimated to be much shorter and more varied than those of previous estimations. This result revises the data used in the current assessment of the probabilities of earthquakes along the Sagami Trough, which could devastate the Tokyo metropolitan area. Furthermore, it demonstrates that the current approach could be a powerful tool to increase the accuracy of assessments of the other areas with depositional marine terraces.

  2. Evaluation and mapping of cultural services in terraced landscapes. The case study of the Amalfi Coast

    Directory of Open Access Journals (Sweden)

    Antonia Gravagnuolo


    Full Text Available Cultural landscapes are a key resource for sustainable development. Among them, terraced landscapes are classified as “evolutive living” landscapes (UNESCO, 2012, an expression of the historical interrelationship between man and his territory. Currently many terraced landscapes are considered at risk because of the changed socio-economic conditions. The need for conservation and effective management of change of this exceptional heritage poses the question of identification of functions and complex values of the landscape, taking into account the needs, views and preferences of local communities. This study aims to identify the terraced landscape values and services based on the ecosystem services theory. It is addressed the issue of evaluation and mapping of cultural services in terraced landscape, with reference to the site of the Amalfi Coast in Campania. The categories of services have been evaluated with the involvement of the local community through a semi-structured questionnaire administered online. The integration of multi-criteria evaluation and spatial analysis in GIS (Geographic Information System has led to the construction of maps of cultural services, which allow displaying the complex relations that link communities to the landscape. The tools for collaborative mapping (Volunteered Geographic Information – VGI have been used for the construction of some of the maps of cultural services, integrating the results of the questionnaire with data related to the direct experience of the users.

  3. Global synthesis of the classifications, distributions, benefits and issues of terracing (United States)

    Wei Wei; Die Chen; Lixin Wang; Stefani Daryanto; Liding Chen; Yang Yu; Yonglong Lu; Ge Sun; Tianjiao Feng


    For thousands of years, humans have created different types of terraces in different sloping conditions, meant to mitigate flood risks, reduce soil erosion and conserve water. These anthropogenic landscapes can be found in tropical and subtropical rainforests, deserts, and arid and semiarid mountains across the globe. Despite the long history, the roles of and the...

  4. Holocene submarine terraces on the western continental shelf of India; implications for sea-level changes

    Digital Repository Service at National Institute of Oceanography (India)

    Wagle, B.G.; Vora, K.H.; Karisiddaiah, S.M.; Veerayya, M.; Almeida, F.

    and the shelf break, being more common between 11~' and 20~'N. The terraces are prominent between water depths of 50 and 115 m and occur at six distinct levels: (1) 55-60 m, (2) 65-70 m, (3) 75-80 m, (4) 85-90 m, (5) 95-100 m and (6) 110-115 m...

  5. Development of optimal terrace pit coal mining systems. Technical progress report, October 1- October 31, 1979

    Energy Technology Data Exchange (ETDEWEB)

    McIntosh, D. G.


    A bibliography on various aspects of optimal terrace pit coal mining systems is included. Relevant federal and state legislation and regulations have been identified. Mines of interest to the project have been identified and listed for field visits. Seven regions of different climates, hydrology, geology, etc., are being studied individually. (LTN)

  6. A new regulation for terrace heaters; ERP: parasols chauffants et cuisson mobile

    Energy Technology Data Exchange (ETDEWEB)



    After a year of discussions, the terrace heaters are from now on entirely authorized. They have indeed just coming to be included in a clear and explicit way in the 'safety rule against the fire and panic risks in the establishments receiving the public. Some precise details are given too for the use of LPG in movable kitchens (exhibition). (O.M.)

  7. A Strontium Isotope Reconnaissance of a Marine Terrace Chronosequence in Central California, USA. (United States)

    Fitzpatrick, J. A.; Bullen, T. D.; Vivit, D. V.; White, A. F.


    Long-term sampling locations have been established on a chronosequence of marine terraces north of Santa Cruz, CA. Investigation of these sites will allow a multi-disciplinary assessment of mineral weathering and soil formation processes. The five surfaces comprising the chronosequence (terraces 1-5) have been dated at 65ka, 92ka, 137ka, 139ka, and 226ka, respectively, by Perg et al, 2001 using cosmogenic radionuclides (CRN). Soil horizons have developed in the sediments covering the terraces, derived locally from the Miocene Santa Margarita sandstone, Santa Cruz mudstone, and the Cretaceous Ben Lomond Granodiorite. The terrace sites have been sampled and instrumented with suction water samplers and precipitation collectors. Bi-monthly collection of soil waters, surface waters, precipitation, and vegetation are on going. This component of the study will use Sr isotopes (87Sr/86Sr) to understand sources, cycling, and behavior of strontium and associated base cations. 87Sr/86Sr measurements have been made on a variety of materials from terrace sites 1-5, including precipitation, soil waters, ground and surface waters, vegetation, ammonium-acetate extractable soil Sr, and soil digests. Additionally, 87Sr/86Sr measurements have been made on local bedrock and beach sands. The measured values of 87Sr/86Sr in the samples range from 0.706 in deep soil water and soil exchange extracts to 0.710 in surface waters and soil digests. Isotopic values for eight precipitation samples at the terraces average 0.7091, reflecting the marine influence. Depth profiles of ammonium-acetate exchangeable soil Sr and soil waters from equivalent depths yield similar values and trends in 87Sr/86Sr (from 0.709 at the top toward 0.706 at 6 meter depth), suggesting that equilibrium is established between exchange sites and associated waters. Decreasing 87Sr/86Sr values with depth suggest a dominant influence of precipitation derived Sr on the cation exchange pool at the surface and emergence of a

  8. Monitoring soil erosion in terraced catchments in Mediterranean regions: a field experiment in Cyprus (United States)

    Camera, Corrado; Djuma, Hakan; Zoumides, Christos; Eliades, Marinos; Bruggeman, Adriana; Abate, Dante; Faka, Marina; Hermon, Sorin


    Terraces retained by dry-stone walls are very common features in mountainous Mediterranean environments. These structures provide accessible agricultural land on steep slopes, favoring water infiltration and reducing water runoff and soil erosion. However, during the last decades, an increasing trend of agricultural land abandonment has resulted in a lack of maintenance of the terrace walls and the onset of a general process of land degradation. The objective of this study is the quantification of soil erosion in a small terraced catchment (10,000 m2), located on the north-eastern slope of the Troodos Mountains (Cyprus), at an elevation of 1,300 m a.s.l. The catchment is cultivated with vineyards and it is representative of the main agricultural land use in the Troodos region. Soil erosion is measured by sediment traps and laser scans are made to assess changes in terrace geometry. In addition, a weather station measuring rainfall, temperature and relative humidity has been installed in the catchment, along with 18 soil moisture sensors, to relate soil erosion processes with climate and (sub)surface hydrology. A total of 10 sediment traps, five pairs, have been installed in the study site, catching five well-maintained sections of a dry-stone wall and five degraded (collapsed) sections. Each trap is 1 m wide. In detail, two terraces, 11 and 14 m long, located at the same elevation and separated by a strip of natural vegetation, are monitored with four and six traps, respectively. To get a complete picture of the erosion processes occurring on the selected area, the trap pairs collect sediment from both the collapsed and the well maintained wall sections of the two terraces. In addition, terrace area of two traps is delineated by metal borders (1x4 m2) to relate erosion rates to a known drainage area. The sediment traps are emptied after all rainfall events. At the beginning and end of the rainy season, a laser scanning survey of a terrace located uphill of the ones

  9. Bedload exports in a forest catchment following wildfire and terracing, north-central Portugal (United States)

    Martins, Martinho A. S.; Machado, Ana I.; Serpa, Dalila; Prats, Sergio A.; Faria, Sílvia R.; Varela, María E. T.; González-Pelayo, Óscar; Keizer, J. Jacob


    In Portugal, the occurrences of wildfires are frequently, on average, affects some 100.000 ha of rural lands each year, but in extreme years such as 2003 and 2005 the burnt areas can go over 300.000 ha. Studies in various parts of the world, including Portugal, have well-documented a strong and sometimes extreme response in overland flow generation and associated soil losses following wildfire. Over the last two decades, the construction of terraces in preparation of a new eucalypt plantation has become increasingly common in the mountain areas of north-central Portugal, including in recently burnt areas. Terraces are traditionally viewed as a soil conservation technique, however, the present authors have measured high splash and inter-rill erosion on recent terraces and have frequently observed gully formation connecting the terraces over the full hill slope length, as well as within the adjacent unsealed roads. The present study was carried out in a forest catchment in the north-central Portugal that was burnt by a wildfire during the summer of 2010 and logged and then terraced with a bulldozer during the winter 2010. The burnt catchment of roughly 25 ha was instrumented with two subsequent flumes with maximum discharge capacities of 120 and 1700 l sec-1. The bed load that deposited in the smallest flume was removed and weighted in the field at regular intervals during the subsequent three years. The records are being now analyzed, nonetheless preliminary results suggested that, besides the wildfire effects, also post-fire land management played an important role on bedload exports.

  10. A landscape character assessment of three terraced areas in Campania region, Italy (United States)

    Gravagnuolo, Antonia; Ronza, Maria; Di Martino, Ferdinando; De Rosa, Fortuna


    Agricultural terraces represent the territorial structure of many cultural landscapes in the Campania region, Italy. Historic urban/rural settlements and hydraulic-agrarian systems have been developed on mountains and hills, producing diverse cultural landscapes depending on the specific geological, pedological and geomorphological characteristics, which influenced the character and functions of terraces. These unique landscapes are multi-functional and provide many ecosystem services: provisioning (food, water retention, building materials); regulating and maintenance (hydrogeological stability, soil fertility, protection from soil erosion, maintenance of genetic diversity, habitat); cultural services (heritage and traditional knowledge conservation, tourism and recreation, spiritual experience, education, aesthetic quality). Three terraced landscapes in Campania are analysed, which present a rich diversity in the geological structure and formal/functional characteristics: the Roccamonfina vulcanic area, a highly fertile and lapillous soil; the Monte di Bulgheria, a clay-rich area; and finally the well-known UNESCO World Heritage site of the Amalfi Coast, a calcareous, steep rock faced area. A landscape character assessment of the three sites is processed, identifying the biophysical structure of the sites, natural systems and land use, and cultural and anthropic elements. Terraced landscapes in Campania can be regenerated, taking again an active social and economic role for the society, enhancing their multifunctionality as a key source of wellbeing. Ecosystem services are mapped and evaluated to assess benefits and costs in a multidimensional framework. Spatial analysis in GIS environment supports this process, providing a decision-support tool for mapping and assessment of terraced landscapes, to convert their actual and potential value into a resource of economic sustainable development.

  11. Two Late Pleistocene climate-driven incision/aggradation rhythms in the middle Dnieper River basin, west-central Russian Plain

    DEFF Research Database (Denmark)

    Panin, Andrei; Adamiec, Grzegorz; Buylaert, Jan-Pieter


    was applied and _30 new numerical ages (OSL and 14C dates) were obtained to establish a chronology of incision and aggradation events that resulted in the current valley morphology. Two full incision/aggradation rhythms and one additional aggradation phase from the previous rhythm were recognized in the Late...... Pleistocene - Holocene climate cycle. The following events were detected. (1) Late MIS 5 - early MIS 4: aggradation of Terrace T1 following the deep incision at the end of MIS 6. (2) Late MIS 4 (40-30 ka): incision into Terrace T1 below the present-day river, formation of the main scarp in the bottom...... of the valley between Terrace T1 and Terrace T0/Floodplain levels. (3) MIS 2: aggradation of Terrace T0, lateral migrations of a shallow braided channel located few meters above the present-day river since ∼25 ka through the LGM. (4) 18-13 ka: incision into Terrace T0 below the modern river. Multiple...

  12. Do agricultural terraces and forest fires recurrence in Mediterranean afforested micro-catchments alter soil quality and soil nutrient content? (United States)

    E Lucas-Borja, Manuel; Calsamiglia, Aleix; Fortesa, Josep; García-Comendador, Julián; Gago, Jorge; Estrany, Joan


    Bioclimatic characteristics and intense human pressure promote Mediterranean ecosystems to be fire-prone. Afforestation processes resulting from the progressive land abandonment during the last decades led to greater biomass availability increasing the risk of large forest fires. Likewise, the abandonment and lack of maintenance in the terraced lands constitute a risk of land degradation in terms of soil quantity and quality. Despite the effects of fire and the abandonment of terraced lands on soil loss and physico-chemical properties are identified, it is not clearly understood how wildfires and abandonment of terraces affect soil quality and nutrients content. Microbiological soil parameters and soil enzymes activities are biomarkers of the soil microbial communitýs functional ability, which potentially enables them as indicators of change, disturbance or stress within the soil community. The objective of this study was to investigate the effects of terracing (abandoned and non-abandoned) on the soil enzyme activities, microbiological soil parameters and soil nutrients dynamics in three Mediterranean afforested micro-catchments (i.e., trend with higher values in terraced plots, although differences were weaker. We conclude that terraced landscapes present poorer soil quality parameters due to land abandonment and the lack of terraced management. In addition, forest fire recurrence exacerbates soil degradation processes due to the direct effects on vegetation and soil properties.

  13. Faulted terrace riser position with respect to meanders constrains late Quaternary slip history of the Honey Lake fault, NE California (United States)

    Gold, R. D.


    Faulted terrace risers are prevalent semi-linear features commonly used to constrain Quaternary slip rates along strike-slip faults. Terrace risers are difficult to date directly and therefore the bracketing upper and lower terrace surfaces commonly are used to constrain their ages. However, if there is a significant difference in the age of the upper and lower terrace surfaces, then large uncertainties in slip rate result. Some investigators try to reduce uncertainties by arguing that either the upper- or lower-terrace age closely approximates the age of a terrace riser. To evaluate where this approach is valid, we use 0.25-m airborne lidar data to analyze three sites where terrace risers are laterally offset by the right-lateral Honey Lake fault in NE California. The terrace risers are bracketed by the same sub-horizontal surfaces: an upper surface defined by the bed of abandoned Lake Lahontan having an age of 15.8 ka and a lower fluvial terrace abandoned after 4.7 ka. We estimate a >4x difference in the amount of lateral offset recorded by the risers, ranging from 7 to 30 m. The amount of offset appears to correspond to the riser position relative to modern stream meanders: smaller offsets are in cutbank locations and the largest offset is in the point-bar location. At face value, the results yield slip rates of 0.5 to 6.4 mm/yr. However, in detail, the largest lateral displacement ( 30 m) places a minimum bound on slip rate of 2 mm/yr since 15.8 ka and the smallest displacement ( 7 m) places a maximum bound on slip rate of 1.5 mm/yr since 4.7 ka. This investigation highlights the challenge of correctly determining whether an upper or lower terrace best approximates the age of a faulted terrace riser. To reduce uncertainties, we advocate considering the terrace riser position in the stream system and characterizing numerous faulted and dated landforms.

  14. Fluvial and glacial implications of tephra localities in the western Wind River basin, Wyoming, U. S. A

    Energy Technology Data Exchange (ETDEWEB)

    Jaworowski, C. (Univ. of Wyoming, Laramie, WY (United States). Dept. of Geology)


    Examination of Quaternary fluvial and glacial deposits in the western Wind River Basin allows a new understanding of the Quaternary Wind River fluvial system. Interbedded fluvial sediments and volcanic ashes provide important temporal information for correlation of Quaternary deposits. In the western Wind River Basin, six mid-Pleistocene localities of tephra, the Muddy Creek, Red Creek, Lander, Kinnear, Morton and Yellow Calf ashes are known. Geochronologic studies confirm the Muddy Creek, Red Creek, Kinnear and Lander ashes as the 620--650ka Lava Creek tephra from the Yellowstone region in northwestern Wyoming. The stratigraphic position and index of refraction of volcanic glass from the Morton and Yellow Calf ashes are consistent with identification as Lava Creek tephra. Approximately 350 feet (106 meters) above the Wind River and 13 miles downstream from Bull Lake, interbedded Wind River fluvial gravels, volcanic glass and pumice at the Morton locality correlate to late (upper) Sacajawea Ridge gravels mapped by Richmond and Murphy. Associated with the oxygen isotope 16--15 boundary, the ash-bearing terrace deposits reveal the nature of the Wind River fluvial system during late glacial-early interglacial times. The Lander and Yellow Calf ashes, are found in terrace deposits along tributaries of the Wind River. Differences in timing and rates of incision between the Wind River and its tributary, the Little Wind River, results in complex terrace development near their junction.

  15. Analysis and interpretation of marine/continental terraces in the central coast of Asturias (NW Spain (United States)

    María Díaz-Díaz, Luis; Flor-Blanco, Germán; López-Fernández, Carlos; Luis, Pando


    This study presents the geographical distribution and topographical features analysis of several marine/continental terraces located in a sector between Nalón estuary and Cape Peñas region (central coast of Asturias, N Spain). Significant flat raised surfaces appear as outstanding landscape features of the Cantabrian coast. They exhibit north facing low gradient slopes (cliff shoreline and the borders are defined by the pre-littoral mountains to the south. These surfaces have a width of no more than 5 km and occasionally may be thinly mantled by many alluvial clastic deposits, very scarce aeolian sands and gravel and/or sand beach deposits. Several studies have shown the importance of these terraces, which are recognized by the preservation of a variable number of levels of flat raised and staggered irregularly surfaces. These surfaces have been used to quantify rates of rock uplift processes. GIS and quantitative analysis of the relief are applied to the recognition and delineation of terraces. Altimetry information comes from the Digital Elevation Model (DEM) Digital (cell size 5 m). The use of slope Digital Slopes Model (DSM) combined with digital lithology layers and hypsometric method allowed us to identify two main new surfaces at altitudes ranging from 75 to 135 m and 85 to 180 m respectively. Levels of surfaces recognized in previous studies may be correlated with this elevations. They are separated by a huge geologic structure (Ventaniella Fault). Thus, two NW-SE direction landward edge of terrace (shoreline angle) was identified. This feature enables correlate these surface or the old knickpoint (foot of the slope) if the terrace has a continental origin. Initial morphology of these terraces has been modified by landscape erosion much more those developed on limestones. Therefore, just a few areas are preserved where flat surfaces are developed in Paleozoic materials (NO) better in siliciclastic rocks. The remaining areas are modelled in the lowest

  16. Existence and convergence to a propagating terrace in one-dimensional reaction-diffusion equations

    CERN Document Server

    Ducrot, Arnaud; Matano, Hiroshi


    We consider one-dimensional reaction-diffusion equations for a large class of spatially periodic nonlinearities (including multistable ones) and study the asymptotic behavior of solutions with Heaviside type initial data. Our analysis reveals some new dynamics where the profile of the propagation is not characterized by a single front, but by a layer of several fronts which we call a terrace. Existence and convergence to such a terrace is proven by using an intersection number argument, without much relying on standard linear analysis. Hence, on top of the peculiar phenomenon of propagation that our work highlights, several corollaries will follow on the existence and convergence to pulsating traveling fronts even for highly degenerate nonlinearities that have not been treated before.

  17. River capture and sediment redistribution in northern Tunisia: The doom of Utica (United States)

    Booth-Rea, Guillermo; Camafort, Miquel; Pérez-Peña, J. Vicente; Melki, Fetheddine; Ranero, César; Azañón, José Miguel; Gracia, Eulalia; Ouadday, Mohamed


    Utica was a flourishing port city in northern Tunisia since the Phoenician times, 12-9th century B.C., until the 4th century A.D.. However, at present it is located 10 km from the coastline after very fast late Holocene progradation of the Mejerda River delta into the bay of Utica. This fast delta progradation occurred after Mejerda River captured Tine River increasing 140 % the river catchment area. Charcoal fragments present in the youngest Tine river terrace at the wind gap give a conventional radiocarbon age of 3240 +/- 30yr BP, indicating that the capture occurred after this date. Quaternary fluvial terraces located in the Tine River paleovalley have been folded and uplifted above a fold related to the active El Alia Tebousouk reverse fault (ETF). Continued uplift of the Tine River valley above the ETF favoured headward erosion of the Medjerda river tributaries creating a transverse drainage that captured Tine River. This capture produced an important change in sediment discharge along the northern Tunisia coast driving sediments to the Gulf of Tunis instead of feeding the Tyrrhenian Sea through the Ichkeul and Bizerte lakes. Although anthropogenic derived degradation of northern Tunisia land for agricultural purposes probably influenced the increase in sediment into the Utica bay, the main cause of rapid progradation of the Medjerda River delta during the late Holocene is related to its increase in drainage area after capturing the Tine River. This process was mostly driven by local contractive tectonics linked to the seismogenic Alia Tebousouk reverse fault.

  18. Digital data sets that describe aquifer characteristics of the Tillman terrace and alluvial aquifer in southwestern Oklahoma (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital polygons of constant hydraulic conductivity values for the Tillman terrace and alluvial aquifer in southwestern Oklahoma. The...

  19. Terrace Farming on Agricultural Land in the Conterminous United States, 1992: National Resource Inventory Conservation Practice 600 (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the estimated percentage of the 1-km grid cell that is covered by or subject to the agricultural conservation practice (CP600), Terrace...

  20. Combining environmental factors and agriculturalists' observations of environmental changes in the traditional terrace system of the Amalfi coast (southern Italy). (United States)

    Savo, Valentina; Caneva, Giulia; McClatchey, Will; Reedy, David; Salvati, Luca


    Terraces are traditional engineered ecosystems that affect the hydro-geological equilibrium, slope stability, and local communities. The aims of this paper are (i) identifying environmental factors that affect terrace stability in the Amalfi Coast, (ii) defining agriculturalists' observations on environmental changes within that system and (iii) exploring potentiality of these observations to better define conservation strategies. All available data on physical and ecological factors recognized to affect the terrace system were collected and analyzed. Interviews were conducted with agriculturalists to obtain long-term observations on environmental factors that interact with this system. Landslides are more frequent where rainfall is high and during winter. Fires have an uneven annual distribution, with higher frequency during summers. Agriculturalists detailed complex interactions among environmental factors, economic elements, and terraces. These observations represent a valuable resource for defining causes and effects of abandonment and for better addressing conservation strategies.

  1. A Review of Heat Transfer in Terraced Houses of Tropical Climate

    Directory of Open Access Journals (Sweden)

    Azzmi Norazura Mizal


    Full Text Available Heat is the process of energy circulation and replacement of air from hot to cold. In tropical climates, more heat is received because of the location of Malaysia of the equatorial line. Excessive heat in buildings causes discomfort to the occupants in tropical climate. Tropical rainforest climate receives higher solar radiation and terrestrial radiation reaching the building envelopes contributes to this problem. The design of the building should be more concern on reducing this heat. This paper provides a review of heat contribution in a terraced house indoor environment for tropical climate. A good comfortable home is part of the sustainable development agenda to improve the quality of life. Terraced houses are the most living quarters in mass living scheme for urban areas. The incoming solar energy from the sun into the building surface cannot be changed, therefore a consideration of passive building design need to be applied in terraced house design. Data collection gathered from this literature survey will assist to identify problems of discomfort occupant. This strategy would assist in improving the building industry in promoting sustainable development in Malaysia.

  2. Gis-supported Analysis of Slope Processes and Soil Erosion In The Terraced Uplands of Yemen (United States)

    Dresen, M.; Rappold, G.

    The mountain ranges of Yemen form part of a unique agricultural landscape with land use terraces. The increasing abandonment of these terraces in the last decades causes serious problems of land degradation due to soil erosion processes, increasing runoff and debris flows. Especially in the study area within the southern uplands, close to the former border between northern and southern Yemen intensive rain and hail storms occur during the rainy season. These cause strong damage to the terraces and induce mass movements in deeply weathered upper slopes. The absence of extensive climatic and topographic data for most parts of the country reduce the possibilities of a complex, process-oriented analysis of slope processes and soil erosion. Remote sensing and GIS techniques are essential for the selection of land use structures and terrain parameters and enable the modelling of soil movement through the integration of short-term climatic data (extreme rainfall events). The study evaluates different methods for the analysis of soil erosion and debris flow risks in the absence of existing erosion or hydrologic models.

  3. Soil losses in rainfed Mediterranean vineyards under climate change scenarios. The effects of drainage terraces.

    Directory of Open Access Journals (Sweden)

    María Concepción Ramos


    Full Text Available Most vines in the Mediterranean are cultivated on bare soils, due to the scarcity of water. In addition, most traditional soil conservation measures have been eliminated to facilitate the movement of machinery in the fields. In such conditions, high erosion rates are recorded. Given the predicted changes in precipitation and an increasing number of extreme events, an increase in erosion processes is expected. In this study, erosion processes under different climate change scenarios were evaluated as well as the effects of implementing drainage terraces in vineyards. Soil losses were simulated using the WEPP model. The results confirmed the relevance of extreme events on annual soil losses. The WEPP model gave satisfactory results in predicting runoff and soil losses, although the soil losses recorded after some extreme events were under-predicted. The model responded to changes in precipitation and because of that a decrease in precipitation gave rise to a decrease in soil losses. For the scenario in 2050, runoff volumes decreased between 19.1 and 50.1%, while erosion rates decreased between 34 and 56%. However, the expected increase in rainfall intensity may contribute to higher erosion rates than at present. The construction of drainage terraces, perpendicular to the maximum slope, 3 m wide and 30 m between terraces, may lead to an average decrease in soil losses of about 45%.

  4. Measurement of terrace deformation and crustal shortening of some renascent fold zones within Kalpin nappe structure

    Institute of Scientific and Technical Information of China (English)

    YANG XiaoPing; RAN YongKang; CHENG JianWu; CHEN LiChun; XU XiWei


    The Kalpin nappe structure is a strongest thrust and fold deformation belt in front of the Tianshan Mountains since the Cenozoic time. The tectonic deformation occurred in 5-6 striking Mesozoic-Cenozoic fold zones, and some renascent folds formed on the recent alluvial-proluvial fans in front of the folded mountains. We used the total station to measure gully terraces along the longitudinal topographic profile in the renascent fold zones and collected samples from terrace deposits for age determination. Using the obtained formation time and shortening amount of the deformed terraces, we calculated the shortening rate of 4 renascent folds to be 0.1±0.03 mm/a, 0.12±0.04 mm/a, 0.59±0.18 mm/a, and 0.26±0.08 mm/a, respectively. The formation time of the renascent folds is some later than the major tectonic uplift event of the Qinghai-Tibet Plateau 0.14 Ma ago. It may be the long-distance effect of this tectonic event on the Tianshan piedmont fold belt.

  5. Hydrological and erosion processes in terraced agricultural fields: observations from a wet Mediterranean region in northern Portugal (United States)

    Nunes, João Pedro; Bernard-Jannin, Léonard; Rodriguez-Blanco, María Luz; Marisa Santos, Juliana; Oliveira Alves Coelho, Celeste; Keizer, Jan Jacob


    Traditional agriculture in the mountainous humid regions of the northwestern Iberian peninsula has relied on terraces for soil retention. In the last decades, a strong afforestation (in many cases with commercial species) has led to the appearance of large forest areas coexisting with traditional agricultural landscapes. Soil erosion research in this region has therefore focused on the impact of forest management practices and associated disturbances such as wildfires. However, there has been little research on the impacts of traditional terracing practices on erosion, and therefore it has been difficult to connect forest research with the wider issue of sediment connectivity in this complex agroforestry landscape. This work tried to address this research gap by monitoring an agricultural terrace in the Caramulo mountains, northern Portugal, during two years. The field site is located in a humid Mediterranean climate region, with c. 1500 mm/y rainfall, overlaying granite bedrock; agricultural practices are a traditional rotation between winter pasture and summer (irrigated) corn cultivation. During this period, the soil properties of the terrace were characterized, and there was a continuous monitoring of rainfall, soil moisture and surface runoff at the outlet, as well as 1 or 2-weekly collections of runoff to measure sediment yield. Occasional measurements of vegetation cover and erosion features (rills) within the plot were also made. Preliminary results indicate that runoff generation occurred mostly due to saturation-excess, possibly linked with the accumulation of groundwater in the lower layers of the soil. After one of the largest events, there was a clear inflow of runoff from outside the terrace, through either the irrigation network linking all terraces or by resurfacing of groundwater. Sediment yield was linked with runoff, but sediment concentration was linked with vegetation cover and was highest during the early stages of pasture growth. However

  6. Twenty Questions Games Always End With Yes

    CERN Document Server

    Gill, John T


    Huffman coding is often presented as the optimal solution to Twenty Questions. However, a caveat is that Twenty Questions games always end with a reply of "Yes," whereas Huffman codewords need not obey this constraint. We bring resolution to this issue, and prove that the average number of questions still lies between H(X) and H(X)+1.

  7. Capital in the Twenty-First Century

    DEFF Research Database (Denmark)

    Hansen, Per H.


    Review essay on: Capital in the Twenty-First Century. By Thomas Piketty . Translated by Arthur Goldhammer . Cambridge, Mass.: The Belknap Press of Harvard University Press, 2014. viii + 685 pp......Review essay on: Capital in the Twenty-First Century. By Thomas Piketty . Translated by Arthur Goldhammer . Cambridge, Mass.: The Belknap Press of Harvard University Press, 2014. viii + 685 pp...

  8. Geomorphology of the Burnt River, eastern Oregon, USA: Topographic adjustments to tectonic and dynamic deformation (United States)

    Morriss, Matthew Connor; Wegmann, Karl W.


    Eastern Oregon contains the deepest gorge in North America, where the Snake River cuts vertically down 2300 m. This deep gorge is known as Hells Canyon. A landscape containing such a topographic feature is likely undergoing relatively recent deformation. Study of the Burnt River, a tributary to the Snake River at the upstream end of Hells Canyon, yields data on active river incision in eastern Oregon, indicating that Quaternary faults are a first order control on regional landscape development. Through 1:24,000-scale geologic mapping, a 500,000-year record of fluvial incision along the Burnt River was constructed and is chronologically anchored by optically stimulated luminescence dating and tephrochronology analyses. A conceptual model of fluvial terrace formation was developed using these ages and likely applies to other non-glaciated catchments in eastern Oregon. Mapped terraces, inferred to have formed during glacial-interglacial cycles, provide constraints on rates of incision of the Burnt River. Incision through these terraces indicates that the Burnt River is down-cutting at 0.15 to 0.57 m kyr- 1. This incision appears to reflect a combination of local base-level adjustments tied to movement along the newly mapped Durkee fault and regional base-level control imposed by the downcutting of the Snake River. Deformation of terraces as young as 38.7 ± 5.1 ka indicates Quaternary activity along the Durkee fault, and when combined with topographic metrics (slope, relief, hypsometry, and stream-steepness), reveals a landscape in disequilibrium. Longer wavelength lithospheric dynamics (delamination and crustal foundering) that initiated in the Miocene may also be responsible for continued regional deformation of the Earth's surface.

  9. Extraction of Terraces on the Loess Plateau from High-Resolution DEMs and Imagery Utilizing Object-Based Image Analysis

    Directory of Open Access Journals (Sweden)

    Hanqing Zhao


    Full Text Available Abstract: Terraces are typical artificial landforms on the Loess Plateau, with ecological functions in water and soil conservation, agricultural production, and biodiversity. Recording the spatial distribution of terraces is the basis of monitoring their extent and understanding their ecological effects. The current terrace extraction method mainly relies on high-resolution imagery, but its accuracy is limited due to vegetation coverage distorting the features of terraces in imagery. High-resolution topographic data reflecting the morphology of true terrace surfaces are needed. Terraces extraction on the Loess Plateau is challenging because of the complex terrain and diverse vegetation after the implementation of “vegetation recovery”. This study presents an automatic method of extracting terraces based on 1 m resolution digital elevation models (DEMs and 0.3 m resolution Worldview-3 imagery as auxiliary information used for object-based image analysis (OBIA. A multi-resolution segmentation method was used where slope, positive and negative terrain index (PN, accumulative curvature slope (AC, and slope of slope (SOS were determined as input layers for image segmentation by correlation analysis and Sheffield entropy method. The main classification features based on DEMs were chosen from the terrain features derived from terrain factors and texture features by gray-level co-occurrence matrix (GLCM analysis; subsequently, these features were determined by the importance analysis on classification and regression tree (CART analysis. Extraction rules based on DEMs were generated from the classification features with a total classification accuracy of 89.96%. The red band and near-infrared band of images were used to exclude construction land, which is easily confused with small-size terraces. As a result, the total classification accuracy was increased to 94%. The proposed method ensures comprehensive consideration of terrain, texture, shape, and

  10. Spatial patterns of (137)Cs inventories and soil erosion from earth-banked terraces in the Yimeng Mountains, China. (United States)

    Zhang, Yunqi; Long, Yi; An, Juan; Yu, Xingxiu; Wang, Xiaoli


    The Yimeng Mountains is one of China's most susceptible regions to soil erosion. In this region, slopes are composed of granite- or gneiss-derived soils that are commonly cultivated using earth-banked terraces. Based on the (137)Cs measurement for nine reference cores, the present study analysed the spatial patterns of (137)Cs inventory and soil erosion using 105 sampling points in a seven-level earth-banked terrace system. The mean (137)Cs inventory, standard deviation, coefficient of variation, and allowable error for the nine reference cores were 987 Bq m(-2), 71 Bq m(-2), 7%, and 6%, respectively, values that may reflect the heterogeneity of the initial (137)Cs fallout deposit. Within each terrace, the (137)Cs inventory generally increases from the rear edge to the front edge, accompanied by a decrease in the erosion rate. This results from planation by tillage and rainfall runoff during the development of the earth-banked terraces. Across the entire seven-level terrace system, (137)Cs inventories decrease from the highest terrace downwards, but increase in the lower terraces, whereas erosion rate displays the opposite trend. These trends are the result of the combined effects of the earth-bank segmented hillslope, the limited protection of the earth banks, and rainfall runoff in combination with tillage. The high coefficients of variation of (137)Cs inventories for the 21 sampling rows, with a mean value of 44%, demonstrate the combined effects of variations in original microtopography, anthropogenic disturbance, the incohesive soils weathered from underlying granite, and the warm climate. Although earth-banked terraces can reduce soil erosion to some extent, the estimated erosion rates for the study area are still very high.

  11. New CHIRP Seismic Images of Submarine Terraces Around San Clemente Island Constrain its Tectonic Evolution and Geomorphology (United States)

    Derosier, B.; Driscoll, N. W.; Graves, L. G.; Holmes, J. J.; Nicholson, C.


    New High-resolution CHIRP data acquired on the R/V Point Loma in 2015 imaged flights of submarine Terraces off of San Clemente Island. Outboard terraces at ~90 to 115 m below sea level (using a nominal water column velocity of 1500 m/s) may correlate with the Marine Isotope Stage 2 (MIS2); the last glacial maximum (LGM). Submarine terraces were mapped on both the gentle sloping windward (west) and the steeper sloping leeward (east) sides of San Clemente Island. The submarine terrace's depths are roughly the same on both sides of the island and suggest uniform uplift. These findings are consistent with the onshore mapping of terraces on San Clemente Island. The island exhibits a marked asymmetry both onshore and offshore, with a steeply dipping eastern margin and a gentle dipping western margin. This marked asymmetry cannot be explained by the uniform uplift of San Clemente Island based on the observed onshore and offshore terraces. In our model, the asymmetry of San Clemente Island records an early phase of predominantly extensional deformation during the middle to late Miocene, with San Clemente Island being the footwall block. Such asymmetry is also observed across the 30-mile bank and the Coronado Bank with steeply dipping eastern margins and gently dipping western margins. New regional multichannel seismic data and reprocessed industry data show no sediment divergence along the hangingwall blocks, which suggests that extensional deformation predated sedimentation. Finally, the elevations of the terraces on San Clemente Island are similar to those observed on the mainland from Baja California to Newport Beach, requiring any tectonic model fitting the uplift pattern of mainland terraces to account for the similar elevations not only along the margin but also across the margin out to 70 nautical miles offshore.

  12. Role of atomic terraces and steps in the electron transport properties of epitaxial graphene grown on SiC

    Directory of Open Access Journals (Sweden)

    H. Kuramochi


    Full Text Available Thermal decomposition of vicinal SiC substrates with self-organized periodic nanofacets is a promising method to produce large graphene sheets toward the commercial exploitation of graphene's superior electronic properties. The epitaxial graphene films grown on vicinal SiC comprise two distinct regions of terrace and step; and typically exhibit anisotropic electron transport behavior, although limited areas in the graphene film showed ballistic transport. To evaluate the role of terraces and steps in electron transport properties, we compared graphene samples with terrace and step regions grown on 4H-SiC(0001. Arrays of field effect transistors were fabricated on comparable graphene samples with their channels parallel or perpendicular to the nanofacets to identify the source of measured reduced mobility. Minimum conductivity and electron mobility increased with the larger proportional terrace region area; therefore, the terrace region has superior transport properties to step regions. The measured electron mobility in the terrace region, ∼1000 cm2/Vs, is 10 times larger than that in the step region, ∼100 cm2/Vs. We conclusively determine that parasitic effects originate in regions of graphene that grow over step edges in 4H-SiC(0001.

  13. Late Quaternary fluvial incision rates in a marine terraced landscape, southeastern Crete, Greece (United States)

    Karymbalis, Efthimios; Papanastassiou, Dimitris; Valkanou, Kanella; Gaki-Papanastassiou, Kalliopi


    Along the southern coast of the island of Crete, a series of five east-west oriented Late Pleistocene marine terraces exist, demonstrating the significant coastal uplift of this area. These terraces, ranging in elevation from 10 to 160m, are deformed by the vertical movements of the NNE-SSW trending and dipping west normal fault of Ierapetra. This study focuses on defining rates of fluvial incision for the last 410 Ka along valley systems that drain the tectonically uplifting area of Ierapetra, south Crete. The studied streams have a N-S flow direction and discharge into the Libyan Sea. Some of them are developed on the uplifted block of the Ierapetra normal fault whereas others drain the subsiding area west of the fault. The lower reaches of the study streams cut down through these marine terraces, which have been recognized, mapped in detail and correlated with Late Pleistocene Oxygen-Isotope Stages of high sea-level stands following the global sea-level fluctuations. These terraces of known age were used as reference surfaces in order to determine fluvial incision rates as the lower reaches of the streams cut down through these platforms. To evaluate incision rates, thirty five topographic valley cross-sections were drawn through fieldwork measurements as well as using a digital elevation model (DEM) produced by detailed topographic diagrams at the scale of 1:5,000. Cross valley profiles were constructed at specific locations where streams cut down the inner edges of the marine terraces because these points correspond precisely to the age of the palaeo-shoreline during the interglacial stage. For each cross-section the ratio of valley floor width to valley height (Vf) and long-term mean stream incision rates were estimated for the last 410 Ka. The geomorphic evolution of the valleys has been mainly affected by the lithology of the bedrock, sea level fluctuations during the late Quaternary, the head-ward erosion and incision of the channels, as well as both the

  14. The Gediz River fluvial archive: A benchmark for Quaternary research in Western Anatolia (United States)

    Maddy, D.; Veldkamp, A.; Demir, T.; van Gorp, W.; Wijbrans, J. R.; van Hinsbergen, D. J. J.; Dekkers, M. J.; Schreve, D.; Schoorl, J. M.; Scaife, R.; Stemerdink, C.; van der Schriek, T.; Bridgland, D. R.; Aytaç, A. S.


    The Gediz River, one of the principal rivers of Western Anatolia, has an extensive Pleistocene fluvial archive that potentially offers a unique window into fluvial system behaviour on the western margins of Asia during the Quaternary. In this paper we review our work on the Quaternary Gediz River Project (2001-2010) and present new data which leads to a revised stratigraphical model for the Early Pleistocene development of this fluvial system. In previous work we confirmed the preservation of eleven buried Early Pleistocene fluvial terraces of the Gediz River (designated GT11, the oldest and highest, to GT1, the youngest and lowest) which lie beneath the basalt-covered plateaux of the Kula Volcanic Province. Deciphering the information locked in this fluvial archive requires the construction of a robust geochronology. Fortunately, the Gediz archive provides ample opportunity for age-constraint based upon age estimates derived from basaltic lava flows that repeatedly entered the palaeo-Gediz valley floors. In this paper we present, for the first time, our complete dataset of 40Ar/39Ar age estimates and associated palaeomagnetic measurements. These data, which can be directly related to the underlying fluvial deposits, provide age constraints critical to our understanding of this sequence. The new chronology establishes the onset of Quaternary volcanism at ∼1320ka (MIS42). This volcanism, which is associated with GT6, confirms a pre-MIS42 age for terraces GT11-GT7. Evidence from the colluvial sequences directly overlying these early terraces suggests that they formed in response to hydrological and sediment budget changes forced by climate-driven vegetation change. The cyclic formation of terraces and their timing suggests they represent the obliquity-driven climate changes of the Early Pleistocene. By way of contrast the GT5-GT1 terrace sequence, constrained by a lava flow with an age estimate of ∼1247ka, span the time-interval MIS42 - MIS38 and therefore do not

  15. Maintenance and recovery of agricultural terraces to reduce geo-hydrological hazards: the Santa Giulia in Centaura (Liguria, Italy) and Valstagna (Veneto, Italy) case studies (United States)

    Giostrella, Paola; Ferrarese, Francesco; Faccini, Francesco; Brandolini, Pierluigi; Lazzeri, Riccardo; Melillo, Massimo; Mozzi, Paolo; Varotto, Mauro; Tarolli, Paolo; Guzzetti, Fausto


    Throughout the World, men have built terraced landscapes to gain ground suitable for cultivation in steep terrain. Beyond the historical and cultural importance of terraced slopes, terraces have played an important role for soil conservation and water management. In many areas, their abandonment has led to more frequent and/or abundant geo-hydrological hazards. We analyse two terraced areas in northern Italy, including (i) the Valstagna prealpine terraces (Veneto) where the Republic of Venice initiated the cultivation of tobacco in 1600, and (ii) the coastal terraces of Santa Giulia di Centaura (Liguria) where terraces host vineyards and olive groves since 2000 years. Using a combination of direct and indirect mapping methods and tools, including LiDAR topographic surveys, the visual interpretation of aerial photographs and the analysis of historical maps, we performed a systematic mapping of the terraces. Using the available maps, we determined statistics for the width, height and extent of stonewalls and we evaluated the historical evolution of the terraces for the past 50 years, considering changes in land use, the expansion of forest, and the changes in the precipitation regime. Finally, through a preliminary cost-benefit analysis, we propose good practices to help the recovery of the terraces in the two study areas.

  16. Quaternary fans and terraces in the Khumbu Himal south of Mount Everest: their characteristics, age and formation (United States)

    Barnard, P.L.; Owen, L.A.; Finkel, R.C.


    Large fans and terraces are frequent in the Khumbu Himal within the high Himalayan valleys south of Mt. Everest. These features are composed of massive matrix- and clast-supported diamicts that were formed from both hyperconcentrated flows and coarse-grained debris flows. Cosmogenic radionuclide (CRN) exposure ages for boulders on fans and terraces indicate that periods of fan and terrace formation occurred at c. 16, c. 12, c. 8, c. 4 and c. 1.5 ka, and are broadly coincident with the timing of glaciation in the region. The dating precision is insufficient to resolve whether the surfaces formed before, during or after the correlated glacial advance. However, the sedimentology, and morphostratigraphic and geomorphological relationships suggest that fan and terrace sedimentation in this part of the Himalaya primarily occurs during glacier retreat and is thus paraglacial in origin. Furthermore, modern glacial-lake outburst floods and their associated deposits are common in the Khumbu Himal as the result of glacial retreat during historical times. We therefore suggest that Late Quaternary and Holocene fan and terrace formation and sediment transfer are probably linked to temporal changes in discharge and sediment load caused by glacier oscillations responding to climate change. The timing of major sedimentation events in this region can be correlated with fans and terraces in other parts of the Himalaya, suggesting that major sedimentation throughout the Himalaya is synchronous and tied to regional climatic oscillations. Bedrock incision rates calculated from strath terrace ages average c. 3.9 mm a−1, suggesting that the overall rate of incision is set by regional uplift.

  17. Age estimates and uplift rates for late Pleistocene marine terraces: Southern Oregon portion of the Cascadia forearc

    Energy Technology Data Exchange (ETDEWEB)

    Muhs, D.R.; Whelan, J.F. (Geological Survey, Denver, CO (United States)); Kelsey, H.M.; McInelly, G.W. (Western Washington Univ., Bellingham (United States)); Miller, G.H. (Univ. of Colorado, Boulder (United States)); Kennedy, G.L. (Los Angeles County Museum of Natural History, CA (United States))


    Interest in the Cascadia subduction zone has increased because recent investigations have suggested that slip along plates at certain types of convergent margins is characteristically accompanied by large earthquakes. In addition, other investigations have suggested that convergent margins can be broadly classified by the magnitude of their uplift rates. The authors generated new uranium series, amino acid, and stable isotope data for southern Oregon marine terrace fossils. These data, along with terrace elevations and two alternative estimates of sea level at the time of terrace formation, allow one to determine terrace ages and uplift rates. Uranium series analysis of fossil coral yields an age of 83 {plus minus} 5 ka for the Whisky Run terrace at Coquille Point in Bandon, Oregon. A combination of amino acid and oxygen isotope data suggest ages of about 80 and 105 ka for the lowest two terraces at Cape Blanco. These ages indicate uplift rates of 0.45-1.05 and 0.81-1.49 m/kyr for Coquille Point and Cape Blanco, respectively. In order to assess the utility of the southern Oregon uplift rates for predicting the behavior of the Cascadia subduction zone, the authors compared late Quaternary uplift rates derived from terrace data from subduction zones around the world. On the basis of this comparison the southern Oregon rates of vertical deformation are not usually high or low. Furthermore, late Quaternary uplift rates show little relationship to the type of convergent margin. In the case of the southern Oregon coast, variability in uplift rate probably reflects local structures in the overriding plate, and the rate of uplift cannot be used as a simple index of the potential for great earthquakes along the southern Cascadia subduction zone.

  18. Terrace Zone Structure in the Chicxulub Impact Crater Based on 2-D Seismic Reflection Profiles: Preliminary Results From EW#0501 (United States)

    McDonald, M. A.; Gulick, S. P.; Gorney, D. L.; Christeson, G. L.; Barton, P. J.; Morgan, J. V.; Warner, M. R.; Urrutia-Fucugauchi, J.; Melosh, H. J.; Vermeesch, P. M.; Surendra, A. T.; Goldin, T.; Mendoza, K.


    Terrace zones, central peaks, and flat floors characterize complex craters like the Chicxulub impact crater located near the northeast coast of the Yucatan Peninsula. The subsurface crater structure was studied using seismic reflection surveying in Jan/Feb 2005 by the R/V Maurice Ewing. We present 2-D seismic profiles including constant radius, regional, and grid profiles encompassing the 195 km width of the crater. These diversely oriented lines clearly show the terrace zones and aid in the search for crater ejecta as we investigate the formation of the crater including the incidence angle and direction of the extraterrestrial object that struck the Yucatan Peninsula 65 million years ago (K-T boundary). Terrace zones form in complex craters after the modification stage as a result of the gravitational collapse of overextended sediment back into the crater cavity. The terrace zone is clearly imaged on seismic profiles confirming the complex structure of the Chixculub crater. Recent work on reprocessed 1996 profiles found different sizes and spacing of the terraces and concluded that the variations in radial structure are a result of an oblique impact. A SW-NE profile from this study was the only line to show a concentration of deformation near the crater rim hinting that the northeast was the downrange direction of impact. We confirm this narrowing in terrace spacing using a profile with a similar orientation in the 2005 images. Through integration of the new dense grid of profiles and radial lines from the 1996 and 2005 surveys we map the 3-D variability of the terrace zones to further constrain impact direction and examine the formative processes of the Chixculub and other large impact craters.

  19. Characterisation and change detection of the agricultural terraced landscape of Costa Viola (Calabria, Italy) in view of its sustainable management (United States)

    Modica, Giuseppe; Praticò, Salvatore; Lanucara, Simone; Di Fazio, Salvatore


    The research presented in this paper aimed at the dynamic characterisation of the historical terraced landscape of 'Costa Viola', a coastal region in South Italy, in view of its sustainable management. Here the agricultural terraces, used for vineyards, over time have occupied very steep sites and today are recognised as worthy of protection because of their high cultural and scenic value. During the last century, because of the loss of economic competitiveness, the agricultural terraces have undergone progressive abandonment, followed by landscape deterioration and increase of hydrogeologic risk. As a consequence it has recently emerged the need to support the permanence of terraced agriculture through a sensitive management of the area, based on a precise and updated knowledge of the landscape system and its ongoing dynamics of change. To this end the main characteristics of the Costa Viola dry-stone terraces and the Land Use/Land Cover (LU/LC) evolution between 1955 and 2012 were analysed. Taking into consideration the very steep slopes of Costa Viola and the need to analyse with high precision the historical evolution of the terraced landscape, they were implemented investigation methods coupling the use of precision tools with in-situ detailed surveys. A parallel diachronic study was also carried out, covering nearly 60 years and aiming to identify the local geomorphological processes and forms (such as landslides) through stereoscopic analysis of high resolution historic aerial photograms (1955 and 1976) compared to full colour digital orthophotos (1988, 2006, 2008, 2012), direct on-field verification, analysis of cadastral data and pluviometric data series. The geomorphological processes were analysed also in relation with the changes occurred over time in the agricultural terraces and in the urban/rural interface evolution. They were implemented a geographic database based on PostGIS and a Spatial Data Infrastructure (SDI) developed in a GFOSS (Geographic

  20. Analysis of River Profiles in northwestern Bhutan (United States)

    de Palézieux, Larissa; Leith, Kerry; Loew, Simon


    With large alluvial plains, narrow gorges, prominent knick points, and chains of terraces or cut-off ridges, the deeply-incised valleys in Bhutan reflect an environment of diverse erosional activity. Topography ranges from 97 m to 7570 m, with characteristic postglacial landscapes typically located above ca 4200 m. The lower latitudes below ca 3000 m show high relief and terraced or linear hillslopes indicative of a fluvial origin. Although full channel analyses in the region suggest significant local tectonic contributions to longitudinal river profiles (Adams et al., 2016), we develop a method to isolate rivers in an apparently homogeneous tectonic block in the mid- to upper- elevations. Profiles of rivers in this region show a consistent pattern with a marked topographic step covering 2000 m of elevation change within 10 km. Field observations of knick points, terraces and cut-off ridges associated with the step suggest a regionally consistent signal resulting from changes in relative uplift or erosion rate. Chi plots correlate well for all channels when the base level is chosen to isolate rivers below the main alluvial plain, suggesting similar fluvial erosion histories in upstream regions. Employing third order topographic derivatives (Minár et al., 2013), we identify low angle slope sections/plateaus corresponding to terraces and/or extrapolated ridges that project onto former valley floor levels. Employing similar methods as those used to correlate fluvial knickpoints, these will be used to test for regionally consistent changes in fluvial and hillslope activity that may be tied to major tectonic or climatic changes. REFERENCES Adams, B., Whipple, K. X., Hodges, K. V. & Heimsath, A. M. 2016: In situ development of high-elevation, low-relief landscapes via duplex deformation in the Eastern Himalayan hinterland, Bhutan, in Journal of Geophysical Research: Earth Surface, 925-938. Minár, J., Jenčo, M., Evans, I. S., Minár, J., Kadlec, M., Krcho, J., Pacina

  1. Quantitative Study of Green Area for Climate Sensitive Terraced Housing Area Design in Malaysia (United States)

    Yeo, O. T. S.; Saito, K.; Said, I.


    Neighbourhood plays a significant role in peoples' daily lives. Nowadays, terraced housing is common in Malaysia, and green areas in the neighborhood are not used to their maximum. The aim of the research is to quantify the types of green area that are most efficient for cooling the environment for thermal comfort and mitigation of Urban Heat Island. Spatial and environmental inputs are manipulated for the simulation using Geographic Information System (GIS) integrated with computational microclimate simulation. The outcome of this research is a climate sensitive housing environment model framework on the green area to solve the problem of Urban Heat Island.

  2. New Dates and Revelations on the Last Interglacial Terrace, Barbados, West Indies (United States)

    Freiburger, N. C.; Gallup, C. D.; Taylor, F. W.; Cheng, H.; Edwards, R. L.


    Fourteen new samples from the last interglacial terrace on Barbados reveal a well-preserved mid-last interglacial deposit. The fossil coral deposit lies ±20 m below the top of the last interglacial terrace, which underlies the University of West Indies on the southwest side of Barbados. Four of the fourteen samples measured with U-Th methods (Edwards et al., 1987) by ICP-MS (Finnigan ELEMENT; Shen et al., 2002) have initial δ234U values within error of the modern value (145.8 +/- 1.7‰ Cheng et al., 2000), suggesting that they provide accurate and reliable ages (Gallup et al., 1994; Thompson, et al., 2005). The base of the outcrop is a mix of Acropora palmata (Ap) and head corals such as Porites. Ap is usually a reef crest coral, but the presence of head corals may indicate growth in deeper waters. New dates from this unit are 126.3 ± 0.8 ka (Porites); 124.6 ± 0.8 ka (Ap); and 121.5 ± 0.7 ka (Ap). This unit is overlain by a lense of coral cobbles containing one head coral tilted on its side that computes an age of 125.7 ± 0.7 ka (Siderastrea). Overlying the cobble unit is a fore-reef unit of Acropora cervacornis; within this unit is a 1.5 m tall sea cave ~1-2 m above the cobble unit, indicating a sea level drop that carved a notch into the deposit of Acropora cervacornis and presumably created the cobbles from the mixed Ap/head coral deposit. The top of the last interglacial terrace at the University of the West Indies has been dated extensively (Gallup et al., 2002). Though none of the samples have initial δ234U values within error of the modern value, the last interglacial U-Th ages and the ~10 m thick deposit of Ap establish that the top of the terrace is the main crest of the last interglacial deposit at this location. Thus, given the mixed species assemblage of the new deposit and its location 20 m below the crest, we conclude that it grew in deeper water during the last interglacial period. The cobble deposit and the sea cave suggest that this deeper

  3. Properties of solonetzes on terraces of salt lakes Bulukhta and Khaki in the Caspian Lowland (United States)

    Shabanova, N. P.; Lebedeva, M. P.


    A comparative assessment of pedogenetic processes in solonetzes (Calcic Gypsic Salic Solonetzes (Siltic, Albic, Cutanic, Differentic)) developing on terraces of lake depressions within the Volga-Ural interfluve of the Caspian Lowland has been performed on the basis of data on their macro- and micromorphological features and chemical, physicochemical, and physical properties. The studied soils have number of common characteristics shaped by the humus-accumulative, solonetzic, eluvial-illuvial, calcification, and gypsification processes. However, it is shown that macro- and micromorphological indicators of solonetzic processes (the development of clay-humus coatings and the character of structural units in the solonetzic (B) horizon) do not always agree with the modern physicochemical conditions of the development of this process. This is explained by differences in the degree and chemistry of the soil salinization and the depth and salinity of the groundwater. Solonetzes developing on the second terrace of Playa Khaki are distinguished by the highest water content and maximum thickness of the horizons depleted of soluble salts. They are characterized by the well-pronounced humus-accumulative process leading to the development of the light-humus (AJ) horizon. In other solonetzes, the accumulation of humus is weaker, and their topsoil part can be diagnosed as the solonetzic-eluvial (SEL) horizon. Active solodic process and illuviation of organomineral substances with the development of thick coatings and infillings in the B horizon are also typical of solonetzes on the second terrace of Playa Khaki. Micromorphological data indicate that, at present, layered clayey coatings in these soils are subjected to destruction and in situ humification owing to the active penetration of plant roots into the coatings with their further biogenic processing by the soil microfauna. The process of gleyzation (as judged from the number of Fe-Mn concentrations) is most active in

  4. Age estimates and uplift rates for Late Pleistocene marine terraces: Southern Oregon portion of the Cascadia Forearc (United States)

    Muhs, Daniel R.; Kelsey, Harvey M.; Miller, Gifford H.; Kennedy, George L.; Whelan, Joseph F.; McInelly, Galan W.


    Marine terraces are prominent landforms along the southern Oregon coast, which forms part of the forearc region of the Cascadia subduction zone. Interest in the Cascadia subduction zone has increased because recent investigations have suggested that slip along plates at certain types of convergent margins is characteristically accompanied by large earthquakes. In addition, other investigations have suggested that convergent margins can be broadly classified by the magnitude of their uplift rates. With these hypotheses in mind, we generated new uranium series, amino acid, and stable isotope data for southern Oregon marine terrace fossils. These data, along with terrace elevations and two alternative estimates of sea level at the time of terrace formation, allow us to determine terrace ages and uplift rates. Uranium series analysis of fossil coral yields an age of 83±5 ka for the Whisky Run terrace at Coquille Point in Bandon, Oregon. A combination of amino acid and oxygen isotope data suggest ages of about 80 and 105 ka for the lowest two terraces at Cape Blanco. These ages indicate uplift rates of 0.45-1.05 and 0.81-1.49 m/kyr for Coquille Point and Cape Blanco, respectively. Late Quaternary uplift rates of marine terraces yield information about deformation in the overriding plate, but it is unclear if such data vary systematically with convergent margin type. In order to assess the utility of the southern Oregon uplift rates for predicting the behavior of the Cascadia subduction zone, we compared late Quaternary uplift rates derived from terrace data from subduction zones around the world. On the basis of this comparison the southern Oregon rates of vertical deformation are not unusually high or low. Furthermore, late Quaternary uplift rates show little relationship to the type of convergent margin. These observations suggest that local structures may play a large role in uplift rate variability. In addition, while the type of convergent margin may place an

  5. A discussion of the risks and benefits of using rock terracing to limit soil erosion in Guizhou Province

    Institute of Scientific and Technical Information of China (English)


    The construction of stone terraces to minimise soil erosion is common throughout Guizhou. This technique, however, has high inherent risk. Stone terraces are usually much higher than those with earth risers. While they trap a greater thickness of soil on the slope they increase the risk of slope failures, reduce moisture and nutrient availability to plants, and thin more soil up slope. The stone risers also threaten long-term productivity. When a riser collapses debris is deposited over the terrace below making farming difficult. These breaches in the terrace focus surface runoff leading to gully formation and increased sediment transport down slope. Artificial drainage systems, often used in conjunction with terracing, compound the risk. These channels prevent precipitation from soaking into the soil. This limits groundwater and soil moisture recharge which reduces the availability of water for crops and the length of the growing season. The rapid drainage of water from the slope reduces the time of concentration of the catchment resulting in an increase in flood activity. Floods are caused by smaller rainstorm events. They arrive faster and peak quicker and higher than before the channels were constructed. Engineering solutions to soil erosion must therefore be used in conjunction with, and are not as a substitute for, good land management strategies. Furthermore, despite changes in land use practices, and the application of new technologies, there is a maximum amount of production that can be obtained from this land on a sustainable basis.

  6. Atomic step-and-terrace surface of polyimide sheet for advanced polymer substrate engineering (United States)

    Tan, G.; Shimada, K.; Nozawa, Y.; Kaneko, S.; Urakami, T.; Koyama, K.; Komura, M.; Matsuda, A.; Yoshimoto, M.


    Typical thermostable and flexible polyimide polymers exhibit many excellent properties such as strong mechanical and chemical resistance. However, in contrast to single-crystal substrates like silicon or sapphire, polymers mostly display disordered and rough surfaces, which may result in instability and degradation of the interfaces between thin films and polymer substrates. As a step toward the development of next-generation polymer substrates, we here report single-atom-layer imprinting onto the polyimide sheets, resulting in an ultrasmooth 0.3 nm high atomic step-and-terrace surface on the polyimides. The ultrasmooth polymer substrates are expected to be applied to the fabrication of nanostructures such as superlattices, nanowires, or quantum dots in nanoscale-controlled electronic devices. We fabricate smooth and atomically stepped indium tin oxide transparent conducting oxide thin films on the imprinted polyimide sheets for future use in organic-based optoelectronic devices processed with nanoscale precision. Furthermore, toward 2D polymer substrate nanoengineering, we demonstrate nanoscale letter writing on the atomic step-and-terrace polyimide surface via atomic force microscopy probe scratching.

  7. Twenty first century climatic and hydrological changes over Upper Indus Basin of Himalayan region of Pakistan (United States)

    Ali, Shaukat; Li, Dan; Congbin, Fu; Khan, Firdos


    This study is based on both the recent and the predicted twenty first century climatic and hydrological changes over the mountainous Upper Indus Basin (UIB), which are influenced by snow and glacier melting. Conformal-Cubic Atmospheric Model (CCAM) data for the periods 1976-2005, 2006-2035, 2041-2070, and 2071-2100 with RCP4.5 and RCP8.5; and Regional Climate Model (RegCM) data for the periods of 2041-2050 and 2071-2080 with RCP8.5 are used for climatic projection and, after bias correction, the same data are used as an input to the University of British Columbia (UBC) hydrological model for river flow projections. The projections of all of the future periods were compared with the results of 1976-2005 and with each other. Projections of future changes show a consistent increase in air temperature and precipitation. However, temperature and precipitation increase is relatively slow during 2071-2100 in contrast with 2041-2070. Northern parts are more likely to experience an increase in precipitation and temperature in comparison to the southern parts. A higher increase in temperature is projected during spring and winter over southern parts and during summer over northern parts. Moreover, the increase in minimum temperature is larger in both scenarios for all future periods. Future river flow is projected by both models to increase in the twenty first century (CCAM and RegCM) in both scenarios. However, the rate of increase is larger during the first half while it is relatively small in the second half of the twenty first century in RCP4.5. The possible reason for high river flow during the first half of the twenty first century is the large increase in temperature, which may cause faster melting of snow, while in the last half of the century there is a decreasing trend in river flow, precipitation, and temperature (2071-2100) in comparison to 2041-2070 for RCP4.5. Generally, for all future periods, the percentage of increased river flow is larger in winter than in

  8. Uplifted Terraces along the Southeastern Coast of Bangladesh Reveal the Extent of 1762 Earthquake Surface Deformation and Potentially Document Prior Earthquakes (United States)

    Mondal, D. R.; McHugh, C.; Steckler, M. S.; Seeber, L.; Akhter, S. H.; Mustaque, S.; Knappett, P. S.


    To better understand geohazards for Bangladesh, the surface expression of the 1762 earthquake and previous earthquakes, we surveyed the coast of Teknaf for evidence of uplift with high precision NetR9, RTX GPS. Previous studies by Aung et al. (2006; 2008) and Wang et al. (2013) documented uplifted terraces along the west coast of Myanmar and linked the youngest terrace to the 1762 Arakan earthquake. Previous studies by Mondal et al. (2015) documented 2.5 m uplifted microatoll corals in the Saint Martin anticline, 10 km southwest from the Teknaf coastline, and linked their uplift by U/Th ages to the 1762 earthquake. Along the southeast Bangladesh coastline, we mapped three geomorphic terraces for 70 km from Teknaf to Cox's Bazar. While GPS measured the location and elevation, an optical level (Theodolite) was used to survey across the different terraces from the beach to the Teknaf anticline foothills. The terraces were also characterized by slope analysis using 30 m SRTM DEM to understand the relation between the terrace geomorphology and potential influence from slope aprons derived from the erosion of the anticline. Our results show that the elevation of three terraces is consistent along the coast, and that terrace elevation ranges from 2-5 m, 5 -7 m and 11-13 m for the youngest, intermediate and oldest terrace, respectively. The youngest terrace, previously dated by McHugh et al. (2015) using C-14 from marine shells obtained from the terrace top, is linked to uplift from the 1762 earthquake. Marine fossils are present in the oldest terrace, and we will present the C-14 age results. Results also suggest that the higher terrace is not prominent in those locations where the slope of the anticline aprons is very high, and they are in a close proximity to each other. The present geomorphic evidence suggests that these terraces were uplifted by three paleoearthquakes, and C-14 ages will provide timing for the uplift. Evidence of terrace uplift derived from our GPS

  9. Refining fault slip rates using multiple displaced terrace risers—An example from the Honey Lake fault, NE California, USA (United States)

    Gold, Ryan D.; Briggs, Richard; Crone, Anthony J.; Duross, Christopher


    Faulted terrace risers are semi-planar features commonly used to constrain Quaternary slip rates along strike-slip faults. These landforms are difficult to date directly and therefore their ages are commonly bracketed by age estimates of the adjacent upper and lower terrace surfaces. However, substantial differences in the ages of the upper and lower terrace surfaces (a factor of 2.4 difference observed globally) produce large uncertainties in the slip-rate estimate. In this investigation, we explore how the full range of displacements and bounding ages from multiple faulted terrace risers can be combined to yield a more accurate fault slip rate. We use 0.25-m cell size digital terrain models derived from airborne lidar data to analyze three sites where terrace risers are offset right-laterally by the Honey Lake fault in NE California, USA. We use ages for locally extensive subhorizontal surfaces to bracket the time of riser formation: an upper surface is the bed of abandoned Lake Lahontan having an age of 15.8 ± 0.6 ka and a lower surface is a fluvial terrace abandoned at 4.7 ± 0.1 ka. We estimate lateral offsets of the risers ranging between 6.6 and 28.3 m (median values), a greater than fourfold difference in values. The amount of offset corresponds to the riser's position relative to modern stream meanders: the smallest offset is in a meander cutbank position, whereas the larger offsets are in straight channel or meander point-bar positions. Taken in isolation, the individual terrace-riser offsets yield slip rates ranging from 0.3 to 7.1 mm/a. However, when the offset values are collectively assessed in a probabilistic framework, we find that a uniform (linear) slip rate of 1.6 mm/a (1.4–1.9 mm/a at 95% confidence) can satisfy the data, within their respective uncertainties. This investigation demonstrates that integrating observations of multiple offset elements (crest, midpoint, and base) from numerous faulted and dated terrace risers at closely spaced

  10. Linking the runoff response at micro-plot and catchment scale following wildfire and terracing, north-central Portugal (United States)

    Martins, Martinho A. S.; Rial-Rivas, María E.; Machado, Ana I.; Serpa, Dalila; Prats, Sergio A.; Faria, Sílvia R.; Varela, María E. T.; González-Pelayo, Óscar; Keizer, J. Jacob


    Wildfires are known as one of the principal natural hazards affecting the Mediterranean region. This includes Portugal, where wildfires have affected some 100.000 ha of rural lands each year. The effects of wildfires on runoff generation and/or the associated soil (fertility) losses have been studied in Portugal for more than two decades. Some of these studies have reported strong and sometimes extreme hydrological responses in recently burnt areas. Forestry operations in such areas have increasingly come to include bench terracing in preparation of new eucalypt plantations. The hydrological impacts of bench terracing, however, have received little research attention so far and the few existing publications are limited to small spatial scales. The construction of terraces is commonly considered an effective practice for soil conservation on steep slopes, having been applied by mankind since early history. Nonetheless, the present authors have measured high rates of splash as well as inter-rill erosion on recently constructed terraces, and have regularly observed rill formation, including on forest tracks which typically constitute an extensive network in such bench terraced plantations. The present study was carried out in a 29-ha forest catchment in north-central Portugal that was burnt by a wildfire during the summer of 2010, logged during early winter 2010/11, and then bench terraced with bulldozers during late winter 2011, some 6 months after the wildfire. The catchment outlet was instrumented immediately after the fire with an automatic hydrometric station comprising two subsequent flumes with maximum discharge capacities of 120 and 1700 l sec-1. Within the catchment, rainfall was measured using several automatic and storage gauges and overland flow was monitored on two contrasting slopes using 3 micro-plots of approximately 0.25m2 on each slope.Overland flow was measured at 1- to 2-weekly intervals during the hydrological years of 2010/11 and 2011/12, i

  11. Twenty-Channel Voice Response System. (United States)


    programs and vocabulary. 0 Telephone Company (TELCO) Switched Lines - provides access to VRS using telephones. * Bell 407C Data Sets - Converts the Touch...from the twenty 407C units. 0 DLII-E - Asynchronous interface to the 11/34 unibus for the VOTRAX unit. * 20 Channel ADPCM Decoder - a specially designed

  12. Educating the Ablest: Twenty Years Later (United States)

    Culross, Rita R.


    This study examines the current lives of thirty-five individuals who participated in high school gifted programs twenty years ago. The research specifically looked at educational attainment and career goals in terms of expressed aspirations in high school, using social media and other Internet sources. Results indicated continued support for the…

  13. Water-quality assessment of part of the upper Mississippi River basin, Minnesota and Wisconsin - Ground-water quality in an urban part of the Twin Cities Metropolitan area, Minnesota, 1996 (United States)

    Andrews, W.J.; Fong, A.L.; Harrod, Leigh; Dittes, M.E.


    In the spring of 1996, the Upper Mississippi River Basin Study Unit of the National Water-Quality Assessment Program drilled 30 shallow monitoring wells in a study area characterized by urban residential and commercial land uses. The monitoring wells were installed in sandy river-terrace deposits adjacent to the Mississippi River in Anoka and Hennepin Counties, Minnesota, in areas where urban development primarily occurred during the past 30 years.

  14. River engineering

    NARCIS (Netherlands)

    De Vries, M.


    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.

  15. Extended study of the atomic step-terrace structure on hexagonal SiC (0 0 0 1) by chemical-mechanical planarization

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Xiaolei [The State Key Laboratory of Tribology, Tsinghua University, Beijing 100084 (China); Shenzhen Key Laboratory of Micro/Nano Manufacturing, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057 (China); Pan, Guoshun, E-mail: [The State Key Laboratory of Tribology, Tsinghua University, Beijing 100084 (China); Shenzhen Key Laboratory of Micro/Nano Manufacturing, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057 (China); Zhou, Yan; Zou, Chunli; Gong, Hua [The State Key Laboratory of Tribology, Tsinghua University, Beijing 100084 (China); Shenzhen Key Laboratory of Micro/Nano Manufacturing, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057 (China)


    The atomic step-terrace structure on hexagonal silicon carbide (0 0 0 1) surface is significant in that it guides the improvement of chemical-mechanical planarization (CMP) and epitaxial technique. The final state of atomic step-terrace structure can be used as a feedback for improving the CMP process, the formula of slurry and the epitaxial technique. In this paper an extended study of the atomic step-terrace structure on 4H- and 6H-SiC (0 0 0 1) planarized by CMP is presented. Surface topography of the (0 0 0 1) facet plane of 4H- and 6H-SiC wafers during CMP process was studied by atomic force microscopy (AFM). The results demonstrate that high-definition atomic step-terrace structure of the (0 0 0 1) facet plane of both 4H- and 6H-SiC can be obtained by appropriate CMP process, and during CMP process, the formation of step-terrace structure had a certain rule. We studied the relationship between the CMP process and the characteristics of the atomic step-terrace structure, and analyzed the possible impact of the CMP process on the status of terraces. We studied the distribution of terraces in different areas of the wafer, and the origin of this distribution was discussed briefly. We also describe the formation of dislocations in hexagonal SiC. The results of this paper may provide some ideas and suggestions for CMP, crystal growth and epitaxy research.

  16. Lateral Erosion Encourages Vertical Incision in a Bimodal Alluvial River (United States)

    Gran, K. B.


    Sand can have a strong impact on gravel transport, increasing gravel transport rates by orders of magnitude as sand content increases. Recent experimental work by others indicates that adding sand to an armored bed can even cause armor to break-up and mobilize. These two elements together help explain observations from a bimodal sand and gravel-bedded river, where lateral migration into sand-rich alluvium breaks up the armor layer, encouraging further incision into the bed. Detailed bedload measurements were coupled with surface and subsurface grain size analyses and cross-sectional surveys in a seasonally-incised channel carved into the upper alluvial fan of the Pasig-Potrero River at Mount Pinatubo, Philippines. Pinatubo erupted in 1991, filling valleys draining the flanks of the volcano with primarily sand-sized pyroclastic flow debris. Twenty years after the eruption, sand-rich sediment inputs are strongly seasonal, with most sediment input to the channel during the rainy season. During the dry season, flow condenses from a wide braided planform to a single-thread channel in most of the upper basin, extending several km onto the alluvial fan. This change in planform creates similar unit discharge ranges in summer and winter. Lower sediment loads in the dry season drive vertical incision until the bed is sufficiently armored. Incision proceeds downstream in a wave, with increasing sediment transport rates and decreasing grain size with distance downstream, eventually reaching a gravel-sand transition and return to a braided planform. Incision depths in the gravel-bedded section exceeded 3 meters in parts of a 4 km-long study reach, a depth too great to be explained by predictions from simple winnowing during incision. Instead, lateral migration into sand-rich alluvium provides sufficient fine sediment to break up the armor surface, allowing incision to start anew and increasing the total depth of the seasonally-incised valley. Lateral migration is recorded in a

  17. Gravel deposit produced by a flash paleoflood in a succession of Quaternary terraces in the Plain of Vic (NE Iberian Peninsula) (United States)

    Castelltort, Xavier; Colombo, Ferran; Carles Balasch, Josep; Barriendos, Mariano; Mazón, Jordi; Pino, David; Lluís Ruiz-Bellet, Josep; Tuset, Jordi


    In contrast with the abundance of studies of fluvial terraces, caused by river dynamics, there are very few descriptions of alluvial deposits produced by flash floods and mass movements. This study describes a late Pleistocene sedimentary deposit produced by a flash paleoflood and attempts to explain its genesis and its source areas. The Plain of Vic, drained by the river Ter and its tributaries, is one of the eastern erosive basins bordering the sedimentary Ebre basin (NE Iberian Peninsula). This plain has a length of 35 km and an average width of 8 km with a N-S direction and lies mainly on the Marls of Vic Fm. These materials are the less resistant lithologic members of the monocline Paleogene stratigraphic succession that dips to the west. The basal resistant bed that forms the eastern cuesta is the Sandstones of Folgueroles Fm. On the top, the resistant lithologic beds that form the scarp face are the sandstones of La Noguera in the Vidrà Fm. On the scarp face, various coalescent alluvial bays have been developed, which have accumulated up to eight levels of alluvial terraces. In one of them, formed by the river Mèder and the Muntanyola stream, a gravel deposit up to 5 m thick formed in a single episode outcrops, in a position T4,. A dating of the river Ter T5 has obtained an age of 117.9 ± 9.5 Ky. The accumulation of gravel erodes another level of metric thickness of the same lithological characteristics and texture. The deposit does not have any internal structure or organization of pebbles. At its base, there are several metric blocks coming directly from the slopes. The accumulation of gravel is block-supported with a sandy matrix. The pebbles size is centimetric to decimetric (90%). Its texture is subrounded. Lithologically, the deposit consists mostly of sandstone and limestone from the top of the series. On the ground, the accumulation of gravel is elongated, with a maximum length and width of 550 m by 160 m and a slope surface of 2.54%. With an area

  18. Twenty Practices of an Entrepreneurial University

    DEFF Research Database (Denmark)

    Gjerding, Allan Næs; Wilderom, Celeste P.M.; Cameron, Shona P.B.;


    similarities; especially that entrepreneurship within universities has to be welcomed and facilitated top-down, but organically occurs and develops bottom-up. Implementing entrepreneurship at universities is thus about stimulating a culture of organic intrapreneurship and we provide practical recommendations...... studies twenty organisational practices against which a University's entrepreneurship can be measured. These twenty practices or factors in effect formed the basis for an entrepreneurship audit. During a series of interviews, the extent to which the universities are seen as entrepreneurial...... by the interviewees was surveyed. We showed that the practices have been implemented only to various degrees and rather unsystematically. There are important differences among the universities, to some extent depending on the level of ambition that each university has regarding each practice. There are also important...

  19. Luminescence dated Late Pleistocene wave-built terraces in northeastern Brazil

    Directory of Open Access Journals (Sweden)

    Kenitiro Suguio


    Full Text Available This study presents field and chronological investigations along the coast of northeastern Brazil from ~4°S to 9°S latitude, which corresponds to ~700 km of coastline under a semi-diurnal mesotidal regime. We investigated wave-built terrace deposits and dated sediments using the optically stimulated luminescence and thermoluminescence methods on quartz grains. The wave-built terraces yielded two main age groups: 200-230 ka and 100-130 ka, which we interpreted as depositional ages. We correlated these age groups with oxygen-isotope stages 7c and 5e, respectively. These events correspond to the antepenultimate and penultimate transgressions along the Brazilian coast. The deposits occur mainly in patches on low-lying flat plateaus along the littoral zone and incision valleys that cut across coastal tablelands. The altitude of the base of the 200-230 ka terraces ranges from 10 m above mean sea level (asl to -2m asl, whereas the base of the 100-130 ka varies from 12 m asl to -2 m asl. Both terraces were deposited in the foreshore and upper shoreface zones. We noted a coincidence between sea-level highstand chronologies in northeastern Brazil and those in the Bahamas and Bermuda.Este estudo apresenta uma investigação de campo e geocronológica realizada ao longo da costa nordeste do Brasil entre ~4°S e 9°S de latitude, o que corresponde a ~700 km de costa submetida a um regime de meso-maré. Nós investigamos terraços marinhos construídos por ondas e datamos sedimentos usando luminescência oticamente estimulada e termoluminescência em grãos de quartzo. Os terraços marinhos forneceram dois grupos de idades: 200-230 ka e 100-130 ka, que interpretamos como idades de deposição. Nós correlacionamos estas idades com idades do estágio isotópico do oxigênio 7c e 5e, respectivamente. Estes eventos correspondem a antepenúltima e penúltima transgressões que ocorreram ao longo da costa brasileira. Os depósitos ocorrem predominantemente em

  20. Narrowing of terrace-width distributions during growth on vicinal surfaces (United States)

    Hamouda, A. BH.; Pimpinelli, A.; Einstein, T. L.


    We present analytic and numerical results for the steady-state, non-equilibrium terrace-width distribution (TWD) of steps during growth on vicinal surfaces. Kinetic Monte Carlo shows that the TWD narrows progressively with increasing flux until the model breaks down. The narrowing corresponds to kinetic repulsion between moving steps, due to the intrinsic asymmetry of the adatom diffusion current on a growing surface. With a 1-dimensional (1D) model, from a Burton-Cabrera-Frank approach, we make contact with previous work, in which the attachment asymmetry can also be due to electromigration or to asymmetry in attachment rates; we deduce an expression for the narrowing via a Fokker-Planck analysis. We illustrate how Ehrlich-Schwoebel barriers (although inducing an instability in 2D) also lead to such asymmetry and narrowing.

  1. Intelligence in the Twenty-First Century



    The author concludes that the world will most probably remain rife with conflict even in the twenty first century and that the traditional role of intelligence will not only continue but will increase in importance. He characterizes the international situation as being "more of the same historically"; that is, the existence of several different centers of power and mutual conflicts based solely on national interests. In order to protect and promote one's national interests, sovereign states w...

  2. Servicing the twenty-first century

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, D. [DTLR, London (United Kingdom)


    Twentieth century governments have committed themselves to the principle of sustainable development. Efforts to fulfil this goal offer an insight into changes in building services provision in the opening decades of the new century. Sustainable development indicators are used to identify possible trends. The analysis also forms the basis for some speculative conjectures as a basis for a research agenda for the twenty-first century. (Author)

  3. Twenty-first century learning in afterschool. (United States)

    Schwarz, Eric; Stolow, David


    Twenty-first century skills increasingly represent the ticket to the middle class. Yet, the authors argue, in-school learning is simply not enough to help students develop these skills. The authors make the case that after-school (or out-of-school) learning programs are emerging as one of the nation's most promising strategies for preparing young people for the workforce and civic life. Most school systems have significant limitations for teaching twenty-first century skills. They have the limits of time: with only six hours per day there is barely enough time to teach even the basic skills, especially for those students starting already behind. They have the limits of structure: typical school buildings and classrooms are not physically set up for innovative learning. They have the limits of inertia and bureaucracy: school systems are notoriously resistant to change. And perhaps most important, they have the limits of priorities: especially with the onset of the No Child Left Behind Act, schools are laserlike in their focus on teaching the basics and therefore have less incentive to incorporate twenty-first century skills. Meanwhile, the authors argue that after-school programs are an untapped resource with three competitive advantages. First, they enable students to work collaboratively in small groups, a setup on which the modern economy will increasingly rely. Second, they are well suited to project-based learning and the development of mastery. Third, they allow students to learn in the real-world contexts that make sense. Yet the after-school sector is fraught with challenges. It lacks focus-Is it child care, public safety, homework tutoring? And it lacks rigorous results. The authors argue that the teaching of twenty-first century skills should become the new organizing principle for afterschool that will propel the field forward and more effectively bridge in-school and out-of-school learning.

  4. Submarine terrace limestones from the continental slope off Saurashtra-Bombay: Evidence of Late Quaternary neotectonic activity

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, V.P.; Veerayya, M.

    Bathymetric and shallow seismic data from the continental slope off Saurashtra-Bombay indicate wide submarine terraces at 130, 145 and 170 m and reefal structures at 320-360 m water depths. 10 cm thick slabs of limestones are recovered from the 130...

  5. Landscape change in mediterranean farmlands: impacts of land abandonment on cultivation terraces in portofino (italy) and lesvos (greece)

    NARCIS (Netherlands)

    Sluis, van der T.; Kizos, T.; Pedroli, G.B.M.


    The Mediterranean landscape has been rapidly changing over the past decades. Many regions saw a population decline, which resulted in changing land use, abandonment of marginal lands and colonisation by shrubs and tree species. Typical features like farming terraces, olive yards, and upland grasslan

  6. Environmental impact of introducing plant covers in the taluses of orchard terraces: implications for erosion and agricultural runoff control

    NARCIS (Netherlands)

    Rodriguez Pleguezuelo, C.R.; Duran Zuazo, V.H.; Francia Martinez, J.R.; Martin Peinado, F.J.; Graaff, de J.; Muriel Fernandez, J.L.


    South-eastern Spain, and in particular the coastal areas of Granada and Malaga, feature a large area under subtropical crops, with orchards established on terraces built along the slopes of the mountainous areas. The climate, characterized by periodically heavy rainfall, variable in space and time,

  7. Archaeological Investigations on the San Antonio Terrace, Vandenberg Air Force Base, California, in Connection with MX Facilities Construction. (United States)


    terraces, beaches, streams) precluded such a treatment . Instead, color variability and collection of samples from distinctive beds at particular...Morris (1966), and a number of *damp and hirsute local shellfish collectors were consulted before compiling the list of common shellfish names in...Plumbing, Electri- cal, Construction Material, Fencing, Roofing, Flooring, Paint Interior Furnishings Lighting, Heating, Furniture, Window Treatment

  8. Improvements in the Weeding of Levee Slope of Terraced Paddy Fields with Statutory Regulation of Places of Scenic Beauty (United States)

    Uchikawa, Yoshiyuki; Kimura, Kazuhiro; Hirata, Ayumi

    A growing number of terraced paddy fields in Japan are being conserved as cultural assets like places of scenic beauty. This has meant that the task of weeding levee slope of these terraced paddy fields has become increasingly important, not only for general maintenance of the terraced paddy fields, but also because of the impact landscape, vegetation and the surrounding environment. However, the steep gradient of the levee slope and lack of footholds mean that the workability and safety associated with this weeding work is problematic. In addition, in the event that an area has been designated as a cultural asset, there are restrictions regarding how it can be modified and local farmers are reluctant to change their traditional farming methods in such cases. This study therefore sought to clarify the actual condition of the levee slope weeding work undertaken in the places of scenic beauty Obasute Tanada district. Empirical validations of potential measures for reforming the work environment were evaluated based on the findings of this investigation. We demonstrated that it is possible to modify current work practices while still maintaining and preserving the terraced paddy fields, even in designated scenic locations. To improve the working environment for levee slope weeding, we propose creating berms to serve as footholds at the toes of slopes.

  9. The gap between plan and practice: Actual energy performance of the zero-energy refurbishment of a terraced house

    NARCIS (Netherlands)

    Xexakis, G.; Van den Dobbelsteen, A.A.J.F.


    Prêt-à-Loger, TU Delft’s entry to the Solar Decathlon Europe 2014 (SDE2014), demonstrated the conversion of a common terraced house to energy neutrality, whilst adding value to its living quality. The house was retrofitted according to principles of smart & bioclimatic design, using local circumstan

  10. Agricultural terraces montoring and modeling: a field survey in Chianti region, Firenze, Italy - First part (United States)

    Preti, Federico; Caruso, Marco; Dani, Andrea; Errico, Alessandro; Guastini, Enrico; Trucchi, Paolo


    The two abstracts present the design and set-up of an experimental field plant whose aim is the study and modeling of water circulation in a terraced slope together with its influence on the stability of the retaining dry stone walls. The pilot plant is located at "Fattoria di Lamole" (Greve in Chianti, Firenze, Italy) where both ancient and recently restored or rebuilt dry stone retaining walls are present. The intense vineyards cultivation makes it very representative in terms of range of external stresses that affect both hillslopes and walls. The research is developed within a bigger framework of landscape preservation as a way to prevent hydrogeological instabilities and landslide risks. First Part A first/preliminary field survey was carried out in order to estimate the hydraulic and mechanical soil characteristics. Field saturated hydraulic conductivity measurements with the Simplified Falling Head (SFH) method on a terrace along an alignment were performed. Infiltrometer tests with a double ring device and soil texture determinations with both fine particle-size and skeleton fraction distributions were also performed. The Direct shear test on undisturbed and reconstituted soil samples will offer an estimation of the Mohr-Coulomb failure envelope parameters (friction angle and cohesion). A reference portion of a dry stone wall will be also monitored. Lateral earth pressure at backfill-retaining wall interface (compared to temperature and air pressure measured values), backfill volumetric water content (both in saturated and unsaturated states) and ground-water level are measured. Acknowledgements Italian Research Project of Relevant Interest (PRIN2010-2011), prot. 20104ALME4, National network for monitoring, modeling, and sustainable management of erosion processes in agricultural land and hilly-mountainous area

  11. Recent uplift of the Atlantic Atlas (offshore West Morocco): Tectonic arch and submarine terraces (United States)

    Benabdellouahed, M.; Klingelhoefer, F.; Gutscher, M.-A.; Rabineau, M.; Biari, Y.; Hafid, M.; Duarte, J. C.; Schnabel, M.; Baltzer, A.; Pedoja, K.; Le Roy, P.; Reichert, C.; Sahabi, M.


    Re-examination of marine geophysical data from the continental margin of West Morocco reveals a broad zone characterized by deformation, active faults and updoming offshore the High Atlas (Morocco margin), situated next to the Tafelney Plateau. Both seismic reflection and swath-bathymetric data, acquired during Mirror marine geophysical survey in 2011, indicate recent uplift of the margin including uplift of the basement. This deformation, which we propose to name the Atlantic Atlas tectonic arch, is interpreted to result largely through uplift of the basement, which originated during the Central Atlantic rifting stage - or even during phases of Hercynian deformation. This has produced a large number of closely spaced normal and reverse faults, ;piano key faults;, originating from the basement and affecting the entire sedimentary sequence, as well as the seafloor. The presence of four terraces in the Essaouira canyon system at about 3500 meters water depth and ;piano key faults; and the fact that these also affect the seafloor, indicate that the Atlantic Atlas is still active north of Agadir canyon. We propose that recent uplift is causing morphogenesis of four terraces in the Essaouira canyon system. In this paper the role of both Canary plume migration and ongoing convergence between the African and Eurasian plates in the formation of the Atlantic Atlas are discussed as possibilities to explain the presence of a tectonic arch in the region. The process of reactivation of passive margins is still not well understood. The region north of Agadir canyon represents a key area to better understand this process.

  12. Two millennia of soil dynamics derived from ancient desert terraces using high resolution 3-D data (United States)

    Filin, Sagi; Arav, Reuma; Avni, Yoav


    Large areas in the arid southern Levant are dotted with ancient terrace-based agriculture systems which were irrigated by runoff harvesting techniques. They were constructed and maintained between the 3rd - 9th centuries AD and abandoned in the 10th century AD. During their 600 years of cultivation, these terraces documented the gradual aggradation of alluvial soils, erosion processes within the drainage basins, as well as flashflood damage. From their abandonment and onwards, they documented 1000 years and more of land degradation and soil erosion processes. Examination of these installations presents an opportunity to study natural and anthropogenic induced changes over almost two millennia. On a global scale, such an analysis is unique as it is rare to find intact manifestations of anthropogenic influences over such time-scales because of landscape dynamics. It is also rare to find a near millennia documentation of soil erosion processes. We study in this paper the aggradation processes within intact agriculture plots in the region surrounding the world heritage Roman-Byzantine ancient city of Avdat, Negev Highlands. We follow the complete cycle of the historical desert agriculture, from the configuration pre-dating the first anthropogenic intervention, through the centuries of cultivation, and up to the present erosion phase, which spans over more than a millennium. We use high resolution 3-D laser scans to document the erosion and the environmental dynamics during these two millennia. The high-resolution data is then utilized to compute siltation rates as well as erosion rates. The long-term measures of soil erosion and land degradation we present here significantly improve our understanding of the mechanism of long-term environmental change acting in arid environments. For sustainable desert inhabitation, the study offers insights into better planning of modern agriculture in similar zones as well as insights on strategies needed to protect such historical

  13. Impacts of terracing on soil erosion control and crop yield in two agro-ecological zones of Rwanda (United States)

    Rutebuka, Jules; Ryken, Nick; Uwimanzi, Aline; Nkundwakazi, Olive; Verdoodt, Ann


    Soil erosion remains a serious limiting factor to the agricultural production in Rwanda. Terracing has been widely adopted in many parts of the country in the past years, but its effectiveness is not yet known. Besides the standard radical (bench) terraces promoted by the government, also progressive terraces (with living hedges) become adopted mainly by the farmers. The aim of this study was to measure short-term (two consecutive rainy seasons 2016A and 2016B) run-off and soil losses for existing radical (RT) and progressive (PT) terraces versus non-protected (NP) fields using erosion plots installed in two agro-ecological zones, i.e. Buberuka highlands (site Tangata) and Eastern plateau (site Murehe) and determine their impacts on soil fertility and crop production. The erosion plot experiment started with a topsoil fertility assessment and during the experiment, maize was grown as farmer's cropping preference in the area. Runoff data were captured after each rainfall event and the collected water samples were dried to determine soil loss. Both erosion control measures reduced soil losses in Tangata, with effectiveness indices ranging from 43 to 100% when compared to the NP plots. RT showed the highest effectiveness, especially in season A. In Murehe, RT minimized runoff and soil losses in both seasons. Yet, the PT were largely inefficient, leading to soil losses exceeding those on the NP plots (ineffectiveness index of -78% and -65% in season A and B, respectively). Though topsoil fertility assessment in the erosion plots showed that the soil quality parameters were significantly higher in RT and NP plots compared to the PT plots on both sites, maize grain yield was not correlated with the physical effectiveness of the erosion control measures. Finally, the effectiveness of soil erosion control measures as well as their positive impacts on soil fertility and production differ not only by terracing type but also by agro-ecological zone and the management or

  14. The Pink and White Terraces of Lake Rotomahana: what was their fate after the 1886 Tarawera Rift eruption? (United States)

    de Ronde, C. E. J.; Fornari, D. J.; Ferrini, V. L.; Walker, S. L.; Davy, B. W.; LeBlanc, C.; Caratori Tontini, F.; Kukulya, A. L.; Littlefield, R. H.


    The Pink and White Terraces that once stood regally on the shores of old Lake Rotomahana, and which were unique in their beauty as a natural wonder of the world, were regarded by the local Māori as a taonga, or treasure, because of the therapeutic qualities of the waters and their majestic appearance. The eruption of Mt. Tarawera on June 10, 1886 is commonly cited as the cause of their demise, with the lake rapidly rising soon thereafter to drown the large, newly formed Rotomahana crater and other volcanic edifices shaped during the excavation of the old lake. Thus, the effects of the eruption have been masked from onlookers for more than 125 years. However, application of state-of-the-art survey techniques usually applied in the marine realm to modern Lake Rotomahana, including AUV surveys with numerous sensors, seismic profiling, water column surveys and deployment of deep sea cameras, has provided a wealth of new information about the state of hydrothermal systems in the lake and the probable fortunes of the Pink and White Terraces. We believe that the majority of both sets of terraces were destroyed during the eruption. However, some tantalizing evidence remains for remnants from both sites to exist to this day. High-resolution bathymetric mapping of the lake floor clearly recognizes some features of the post-1886 landscape, including a prominent landmark known as The Pinnacle. If we accept the postulated location of The Pinnacle on a pre-1886 map of Lake Rotomahana, then we appear to have captured a photograph of one of the buttresses to a tier of the nearby White Terraces. More revealing, are side-scan sonar images of structures located in the correct position of the Pink Terraces with respect to The Pinnacle, albeit ~ 20 m deeper than expected if the pre-1886 lake level of 292 m above sea level is to be believed. This work clearly shows that the greater Pink Terraces hydrothermal system survived the eruption and is very active today, whereas that part of


    Directory of Open Access Journals (Sweden)



    Full Text Available El presente trabajo tiene como principal objetivo la concentración y refino de minerales densos presentes en las terrazas aluviales cuaternarias del río Miño (NW Spain ricas en un material de granulometría fina y elevada densidad caracterizado como arenas negras. La recuperación de estas arenas y su salida al mercado supone el aprovechamiento completo del recurso, incidiendo en la sostenibilidad de la explotación y permitiendo reducir costes medioambientales. Los estudios realizados en estas arenas negras revelan la existencia de dos fracciones granulométricas de interés: la más gruesa es rica en oro y la más fina en minerales densos principalmente monacita, ilmenita, circón y casiterita y en menor proporción granates, rutilo, andalucita y xenotima. Sobre esta segunda fracción se han optimizado los métodos de caracterización química y mineralógica para determinar su ley, y los procedimientos de concentración y refinado automatizados. Como resultado, se plantea la combinación de técnicas de separación en seco con separadores magnéticos y electrostáticos para tratar el concentrado primario que se obtiene de la concentración gravitacional por vía húmeda ya existente. Los resultados obtenidos de estas pruebas indican que se pueden obtener elevadas leyes en los minerales de interés.


    Directory of Open Access Journals (Sweden)

    Saúl Flores-Maya


    Full Text Available El objetivo de este estudio fue determinar la distribución espacial, el número cromosómico y el cariotipo deAgave marmorataRoezl yAgave peacockiiCroucher dentro del Valle de Zapotitlán Salinas, Puebla. Este estudio reporta por primera vez el número cromosómico deA. marmoratayA. peacockii, cuyos niveles de ploidía en ambas especies es de 2n=2x=60. Por otra parte, la distribución deA. marmorataen el área estudiada es más amplia respeto deA. peacockiique únicamente se la encuentra al suroeste. La distribución espacial deA. peacockiiestá limitada por la variación en las condiciones del suelo, los tipos de vegetación de la zona, por su condición de diploide (2x y su posible carácter híbrido, por lo tanto, su presencia en la zona depende de la sincronización de la floración de sus progenitores y su capacidad de reproducción sexual y asexual.

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

    Institute of Scientific and Technical Information of China (English)


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

  18. Geomorphology of the Urümqi River Valley and the uplift of the Tianshan Mountains in Quaternary

    Institute of Scientific and Technical Information of China (English)

    周尚哲; 焦克勤; 赵井东; 张世强; 崔建新; 许刘兵


    The Shaerqiaoke Gravel, more than 400 m in thickness, on the north piedmont of the Tianshan Mountains, is located at the exit of the Urümqi River Valley and belongs to the Molasse construction of the Tianshan Mountains. Another uplift event with the tectonic boundary expansion ended the deposition of the Shaerqiaoke Gravel, and resulted in folding, faulting and down-erosion in the frontier of the deposit. The ESR dating indicates that the top of the Shaerqiaoke Gravel accumulated before 1148 kaBP, probably responding to the Kunlun-Huanghe movement of the Qinghai-Tibetan plateau. After that time, erosion-deposition cycle occurred and 9 terraces developed. The TL and ESR dating techniques were employed to date these terraces, and the results indicate that Terrace 3 was formed at MIS 6. Terrace 2 at Houxia also developed simultaneously. Terraces 5 and 6 were accumulated in 338 kaBP and 562-591 kaBP, respectively. The oldest glaciation, named Gao Wangfeng, correlates to MIS 12.

  19. Late Quaternary uplift rate inferred from marine terraces, Muroto Peninsula, southwest Japan: Forearc deformation in an oblique subduction zone (United States)

    Matsu'ura, Tabito


    Tectonic uplift rates across the Muroto Peninsula, in the southwest Japan forearc (the overriding plate in the southwest Japan oblique subduction zone), were estimated by mapping the elevations of the inner edges of marine terrace surfaces. The uplift rates inferred from marine terraces M1 and M2, which were correlated by tephrochronology with marine isotope stages (MIS) 5e and 5c, respectively, include some vertical offset by local faults but generally decrease northwestward from 1.2-1.6 m ky- 1 on Cape Muroto to 0.3-0.7 m ky- 1 in the Kochi Plain. The vertical deformation of the Muroto Peninsula since MIS 5e and 5c was interpreted as a combination of regional uplift and folding related to the arc-normal offshore Muroto-Misaki fault. A regional uplift rate of 0.46 m ky- 1 was estimated from terraces on the Muroto Peninsula, and the residual deformation of these terraces was attributed to fault-related folding. A mass-balance calculation yielded a shortening rate of 0.71-0.77 m ky- 1 for the Muroto Peninsula, with the Muroto-Misaki fault accounting for 0.60-0.71 m ky- 1, but these rates may be overestimated by as much as 10% given variations of several meters in the elevation difference between the buried shoreline angles and terrace inner edges in the study area. A thrust fault model with flat (5-10° dip) and ramp (60° dip) components is proposed to explain the shortening rate and uplift rate of the Muroto-Misaki fault since MIS 5e. Bedrock deformation also indicates that the northern extension of this fault corresponds to the older Muroto Flexure.

  20. Exploring the State of Retention of Traditional Ecological Knowledge (TEK in a Hani Rice Terrace Village, Southwest China

    Directory of Open Access Journals (Sweden)

    Zheng Yuan


    Full Text Available Traditional Ecological Knowledge (TEK is one of the components of the Globally Important Agricultural Heritage Systems (GIAHS, which are good examples of evolutionary adapted socio-ecosystems in human history. The Hani Rice Terraces System, located in China’s southwestern Yunnan Province, is a living example of GIAHS. The Hani Rice Terraces system has existed for more than one thousand years, following TEK related to cultivation and natural resources management, which was collected and practiced continually. Over this long time period, TEK has enabled the Hani people to manage their terraces and other natural resources in a sustainable way. This paper concentrates on the TEK transferring in the current Hani community, taking a small village, Mitian, as an example. Grouping the interviewees into three different age groups (young group, 0–30 years old; middle-age group, 31–50 years old; old group > 50 years old, we investigated their understanding and participation in 13 items of TEK in relation to rice cultivation and water utilization. The items of TEK were divided into four categories, namely “Festivals”, “Beliefs”, “Folk Songs”, and “Water Management”. From the data collected, it was learned that all the items of TEK are well known, but not necessarily practiced. Age and gender have significant influences on farmers’ understanding and participation in TEK. Our analysis suggested that both the knowledge and the practice showed declining trends from the older to the younger age group. Men and women behave differently in practices. In general, it is shown that TEK is declining in the Hani villages which will affect the rice terrace system in ways that are yet unknown. It is likely that a blended TEK, with old and new knowledge and practices, will emerge to sustain the upland rice terrace systems of Yunnan.

  1. Pleistocene terrace deposition related to tectonically controlled surface uplift: An example of the Kyrenia Range lineament in the northern part of Cyprus (United States)

    Palamakumbura, Romesh N.; Robertson, Alastair H. F.


    In this study, we consider how surface uplift of a narrow mountain range has interacted with glacial-related sea-level cyclicity and climatic change to produce a series of marine and non-marine terrace systems. The terrace deposits of the Kyrenia Range record rapid surface uplift of a long-lived tectonic lineament during the early Pleistocene, followed by continued surface uplift at a reduced rate during mid-late Pleistocene. Six terrace depositional systems are distinguished and correlated along the northern and southern flanks of the range, termed K0 to K5. The oldest and highest (K0 terrace system) is present only within the central part of the range. The K2-K5 terrace systems formed later, at sequentially lower levels away from the range. The earliest stage of surface uplift (K0 terrace system) comprises lacustrine carbonates interbedded with mass-flow facies (early Pleistocene?). The subsequent terrace system (K1) is made up of colluvial conglomerate and aeolian dune facies on both flanks of the range. The later terrace systems (K2 to K5) each begin with a basal marine deposit, interpreted as a marine transgression. Deltaic conglomerates prograded during inferred global interglacial stages. Overlying aeolian dune facies represent marine regressions, probably related to global glacial stages. Each terrace depositional system was uplifted and preserved, followed by subsequent deposits at progressively lower topographic levels. Climatic variation during interglacial-glacial cycles and autocyclic processes also exerted an influence on deposition, particularly on short-period fluvial and aeolian deposition.

  2. Systematization of river valleys in different morphostructural areas (United States)

    Opekunova, Marina


    characteristics: 1) name, 2) orographic location, 3) topological order, 4) belonging to a morphostructure of the higher order, 5) belonging to a morphostructural area, and 6) morphostructural characteristics. Then, the location of river valleys towards morphostructures is identified. For this purpose, the layer of the hydrographic network was divided according to obtained polygons of morphostructures. Thus, each streamflow appeared to be either within one morphostructural area or within few ones. In the database every streamflow (valley) or its part also have the following characteristics: 1) name of the river, 2) morphodynamic channel type, 3) direction of the current state of the processes of erosion or accumulation, 4) morphology of terraces, and 5) characteristics of the alluvium. The final research result is preliminary correlation of river terraces of the rivers, crossing several morphostructures of different orders, selection of local, cyclic terraces, and analysis of longitudinal profiles of terraces, focusing on their behavior in the transition zones from one morphostructural area to another one. This approach helps to systematize the forms of fluvial relief formation, formed under different conditions. The reported study was partially supported by RFBR, research project No. 13-05-00517 a.

  3. Creating a catchment perspective for river restoration (United States)

    Benda, L.; Miller, D.; Barquín, J.


    One of the major challenges in river restoration is to identify the natural fluvial landscape in catchments with a long history of river control. Intensive land use on valley floors often predates the earliest remote sensing: levees, dikes, dams, and other structures alter valley-floor morphology, river channels and flow regimes. Consequently, morphological patterns indicative of the fluvial landscape including multiple channels, extensive floodplains, wetlands, and fluvial-riparian and tributary-confluence dynamics can be obscured, and information to develop appropriate and cost effective river restoration strategies can be unavailable. This is the case in the Pas River catchment in northern Spain (650 km2), in which land use and development have obscured the natural fluvial landscape in many parts of the basin. To address this issue we coupled general principles of hydro-geomorphic processes with computer tools to characterize the fluvial landscape. Using a 5-m digital elevation model, valley-floor surfaces were mapped according to elevation above the channel and proximity to key geomorphic processes. The predicted fluvial landscape is patchily distributed according to topography, valley morphology, river network structure, and fan and terrace landforms. The vast majority of the fluvial landscape in the main segments of the Pas River catchment is presently masked by human infrastructure, with only 15% not impacted by river control structures and development. The reconstructed fluvial landscape provides a catchment scale context to support restoration planning, in which areas of potential ecological productivity and diversity could be targeted for in-channel, floodplain and riparian restoration projects.

  4. Creating a catchment perspective for river restoration

    Directory of Open Access Journals (Sweden)

    L. Benda


    Full Text Available One of the major challenges in river restoration is to identify the natural fluvial landscape in catchments with a long history of river control. Intensive land use on valley floors often predates the earliest remote sensing: levees, dikes, dams, and other structures alter valley-floor morphology, river channels and flow regimes. Consequently, morphological patterns indicative of the fluvial landscape including multiple channels, extensive floodplains, wetlands, and fluvial-riparian and tributary-confluence dynamics can be obscured, and information to develop appropriate and cost effective river restoration strategies can be unavailable. This is the case in the Pas River catchment in northern Spain (650 km2, in which land use and development have obscured the natural fluvial landscape in many parts of the basin. To address this issue we coupled general principles of hydro-geomorphic processes with computer tools to characterize the fluvial landscape. Using a 5-m digital elevation model, valley-floor surfaces were mapped according to elevation above the channel and proximity to key geomorphic processes. The predicted fluvial landscape is patchily distributed according to topography, valley morphology, river network structure, and fan and terrace landforms. The vast majority of the fluvial landscape in the main segments of the Pas River catchment is presently masked by human infrastructure, with only 15% not impacted by river control structures and development. The reconstructed fluvial landscape provides a catchment scale context to support restoration planning, in which areas of potential ecological productivity and diversity could be targeted for in-channel, floodplain and riparian restoration projects.

  5. Assessing geomorphic sensitivity in relation to river capacity for adjustment (United States)

    Reid, H. E.; Brierley, G. J.


    River sensitivity describes the nature and rate of channel adjustments. An approach to analysis of geomorphic river sensitivity outlined in this paper relates potential sensitivity based on the expected capacity of adjustment for a river type to the recent history of channel adjustment. This approach was trialled to assess low, moderate and high geomorphic sensitivity for four different types of river (10 reaches in total) along the Lower Tongariro River, North Island, New Zealand. Building upon the River Styles framework, river types were differentiated based upon valley setting (width and confinement), channel planform, geomorphic unit assemblages and bed material size. From this, the behavioural regime and potential for adjustment (type and extent) were determined. Historical maps and aerial photographs were geo-rectified and the channel planform digitised to assess channel adjustments for each reach from 1928 to 2007. Floodplain width controlled by terraces, exerted a strong influence upon reach scale sensitivity for the partly-confined, wandering, cobble-bed river. Although forced boundaries occur infrequently, the width of the active channel zone is constrained. An unconfined braided river reach directly downstream of the terrace-confined section was the most geomorphically sensitive reach. The channel in this reach adjusted recurrently to sediment inputs that were flushed through more confined, better connected upstream reaches. A meandering, sand-bed river in downstream reaches has exhibited negligible rates of channel migration. However, channel narrowing in this reach and the associated delta indicate that the system is approaching a threshold condition, beyond which channel avulsion is likely to occur. As this would trigger more rapid migration, this reach is considered to be more geomorphically sensitive than analysis of its low migration rate alone would indicate. This demonstrates how sensitivity is fashioned both by the behavioural regime of a reach

  6. The dams of the Columbia river; Staustufen des Columbia River

    Energy Technology Data Exchange (ETDEWEB)

    Trueb, L.F.


    The Columbia river and its tributaries in the north-western part of the USA form one of the largest river systems of the world. Its development was started during the economic crisis of the thirties with the construction of the Bonneville, Rock Island, and Grand Coulee dams. Another eight dams were realized between the fifties and the beginning of the seventies. As a terraced lake system the Columbia yields more than 90 terawatt hours of electric power annually and provides irrigation to 200 000 hectares of cultivated land. (orig.) [Deutsch] Der Columbia und seine Nebenfluesse im Nordwesten der USA bilden eines der groessten Flusssysteme der Welt. Seine Erschliessung begann waehrend der Wirtschaftskrise der dreissiger Jahre mit dem Bau der Talsperren Bonneville, Rock Island und Grand Coulee. Weitere acht Staustufen wurden von den fuenfziger Jahren bis Anfang der siebziger Jahre verwirklicht. Als Treppe von Seen liefert der Columbia jaehlich ueber 90 TWh elektrische Energie und ermoeglicht die Bewaesserung von 200 000 Hektar Kulturland. (orig.)

  7. The influence of the maintenance of terraced areas on slope stability during the November 2014 flood event in Liguria (northwestern Italy) (United States)

    Giordan, Daniele; Poggi, Flavio; Baldo, Marco; Cignetti, Martina


    Terraced environments are a widespread feature of the coastal settlement of eastern Liguria (northwestern Italy) and they constitute a well-known favorable role in slope stability. In this region, starting from the twentieth century, the progressive abandonment of agriculture determines a progressively increasing lack of maintenance of the terraces, consequently raising the level of slope instability. Moreover, it should be taken into account not only the level of terraces maintenance, but also their interaction with several factors as i) geological and geomorphological conditions, ii) soil properties, iii) hydrological and hydrogeological conditions, and iv) land use, causing an increase in landslides occurrence. The definition of managed terraces effects on slope stability and their response to external stress like a flood event is rather complicated; a possible approach is a statistical analysis of the effects of a flood event over a large terraced area, distinguishing the maintained sectors from the abandoned ones. After the November 2014 flood event, which affected several sectors of the Liguria region, where a high number of shallow landslides were triggered, an airborne LiDAR survey of the damaged area was carried out. In particular, a high resolution Digital Terrain Model (DTM) resampled to a lower density (1 square meter grid spacing) and a photogrammetric coverage of the area was performed, in order to create a landslide map of the flood event. The surveyed area covered more than 380 square kilometers, and over 1600 shallow landslides triggered by the flood event were identified and inventoried. The high resolution DTM allowed the identification of terraced areas also in wooded sectors and a sharp mapping of the extension of terraced slopes in this portion of Liguria region. By considering: i) the terraced areas recognized through DTM analysis, ii) the mapped landslides, and iii) the land use classification, a correlation between the presence of terraces

  8. Configuration and Correlation of Fluvial Terrace Deposits In the Lower Rio Salado Valley: A Record of Magmatic Uplift and Active Normal Faulting in the Rio Grande Rift (United States)

    Sion, B. D.; Axen, G. J.; Phillips, F. M.; Harrison, B.


    The Rio Salado is a western tributary of the Rio Grande whose valley is flanked by six major terrace levels. The Rio crosses several active rift-related normal faults and the active, mid-crustal Socorro Magma Body (SMB; a sill at 19 km depth that is actively doming the land surface), providing an unusual opportunity to explore the effects of deep magma emplacement and active faulting on the terraces. Rio Salado terraces were mapped using a high-resolution DEM and digital color stereophotographs and were projected onto a valley-parallel vertical plane to construct longitudinal profiles. Three new soil pits were described to aid terrace correlation. A net incision rate of 0.41 ± 0.06 m/ka was inferred from the correlation of a major fill-cut terrace to the 122 ± 18 ka Airport surface ~25 km south of the Rio Salado. This incision rate is >1.5 times more rapid than estimated rates nearby or in other parts of New Mexico, but yields age estimates for other terraces that are consistent with soil development. Terrace gradients in the Rio Salado have increased through time, indicating either stream response to Rio Grande incision or footwall tilting from the Quaternary Loma Blanca fault (LBF). Two terraces in the LBF hanging wall are back-tilted relative to their footwall counterparts, suggesting a listric geometry for the LBF. However, two others (Qtf and Qtc) are east-tilted relative to their footwall counterparts. Both Qtf and Qtc merge eastward with the next youngest terrace in the flight, and Qtc is arched, consistent with an earlier episode of surface uplift above the SMB. Future work will involve (a) additional terrace mapping over the SMB, (b) cosmogenic 36Cl depth profile dating of the Rio Salado terraces to determine incision rates, allow regional terrace correlations, and constrain fault-slip slip rates and the record of SMB-related surface uplift, and (c) numerical modeling of SMB inflation constrained by uplift signals.

  9. Runoff and inter-rill erosion in a Maritime Pine and a Eucalypt plantation following wildfire and terracing in north-central Portugal


    Martins, Martinho A.S.; Machado, Ana I.; Serpa, Dalila; Faria, Sílvia R.; Prats, Sergio A.; Varela, María E.T.; González-Pelayo, Óscar; Keizer, J. Jacob


    The purpose of this study was to assess how terracing affected overland flow and associated sediment losses, at the micro-plot scale (0.25 m2), in recently burnt stands of the two principal forest types in north-central Portugal, i.e. mono-specific stands of Maritime Pine and Eucalypt. Terracing is an increasingly common practice of slope engineering in the study region but its impacts on runoff and erosion are poorly studied. Non-terraced plots at the Eucalypt and the Pine site revealed simi...

  10. Water quality and possible sources of nitrate in the Cimarron Terrace Aquifer, Oklahoma, 2003 (United States)

    Masoner, Jason R.; Mashburn, Shana L.


    Water from the Cimarron terrace aquifer in northwest Oklahoma commonly has nitrate concentrations that exceed the maximum contaminant level of 10 milligrams per liter of nitrite plus nitrate as nitrogen (referred to as nitrate) set by the U.S. Environmental Protection Agency for public drinking water supplies. Starting in July 2003, the U.S. Geological Survey, in cooperation with the Oklahoma Department of Environmental Quality, conducted a study in the Cimarron terrace aquifer to assess the water quality and possible sources of nitrate. A qualitative and quantitative approach based on multiple lines of evidence from chemical analysis of nitrate, nitrogen isotopes in nitrate, pesticides (indicative of cropland fertilizer application), and wastewater compounds (indicative of animal or human wastewater) were used to indicate possible sources of nitrate in the Cimarron terrace aquifer. Nitrate was detected in 44 of 45 ground-water samples and had the greatest median concentration (8.03 milligrams per liter) of any nutrient analyzed. Nitrate concentrations ranged from nitrate concentrations exceeding the maximum contaminant level of 10 milligrams per liter. Nitrate concentrations in agricultural areas were significantly greater than nitrate concentrations in grassland areas. Pesticides were detected in 15 of 45 ground-water samples. Atrazine and deethylatrazine, a metabolite of atrazine, were detected most frequently. Deethylatrazine was detected in water samples from 9 wells and atrazine was detected in samples from 8 wells. Tebuthiuron was detected in water samples from 5 wells; metolachlor was detected in samples from 4 wells; prometon was detected in samples from 4 wells; and alachlor was detected in 1 well. None of the detected pesticide concentrations exceeded the maximum contaminant level or health advisory level set by the U.S. Environmental Protection Agency. Wastewater compounds were detected in 28 of 45 groundwater samples. Of the 20 wastewater compounds

  11. Holocene ethnobotanical and paleoecological record of human impact on vegetation in the Little Tennessee River Valley, Tennessee (United States)

    Delcourt, Paul A.; Delcourt, Hazel R.; Cridlebaugh, Patricia A.; Chapman, Jefferson


    Human occupation and utilization of plant resources have affected vegetation in the lower Little Tennessee River Valley of East Tennessee for 10,000 yr. Changes in Indian cultures and land use are documented by radiocarbon chronologies, lithic artifacts, ceramics, settlement patterns, and ethnobotanical remains from 25 stratified archaeological sites within the Holocene alluvial terrace. The ethnobotanical record consists of 31,500 fragments (13.7 kg) of wood charcoal identified to species and 7.7 kg of carbonized fruits, seeds, nutshells, and cultigens from 956 features. Pollen and plant macrofossils from small ponds both in the uplands and on lower stream terraces record local vegetational changes through the last 1500 to 3000 yr. Human impact increased after cultigens, including squash and gourd, were introduced ca. 4000 yr B.P. during the Archaic cultural period. Forest clearance and cultivation disturbed vegetation on both the floodplain and lower terraces after 2800 yr B.P., during the Woodland period. Permanent Indian settlements and maize and bean agriculture extended to higher terraces 1.5 km from the floodplain by the Mississippian period (1000 to 300 yr B.P.). After 300 yr B.P., extensive land clearance and cultivation by Historic Overhill Cherokee and Euro-Americans spread into the uplands beyond the river valley.

  12. Radiocarbon dating of the Early Natufian at el-Wad Terrace, Mount Carmel, Israel (United States)

    Eckmeier, E.; Yeshurun, R.; Weinstein-Evron, M.; Mintz, E.; Boaretto, E.


    The Natufian culture (15-11.5 kyr BP) of the Levant played an integral role in the transition from nomadic hunter-gatherers to the establishment of sedentism and, finally, to food producing societies of the Neolithic. The Natufian sites in the Southern Levant are characterised by a lack of macrobotanical remains, including charcoal, and a poor preservation of bone collagen. A result of the scarcity of radiocarbon dateable material is that only about 30 reliable radiocarbon dates from the Natufian are available for constructing a chronology of this period, which would enable a better synchronisation of archaeological and environmental data. A key question of Natufian research is if and to what extent past climate changes influenced the lifestyle of the Natufian communities, but the prerequisite for the correlation of cultural and environmental events in time are accurate chronologies. Therefore, a chronological framework with dates from well-defined contexts and samples of good quality is essential for the investigation of the Natufian. We present new C-14 data from the site of el-Wad Terrace, one of the major Natufian hamlets of the 'core area' of this culture. The samples (12 charcoals and 34 bones, of which 6 charcoals and 5 bones were suitable for dating) were derived from Early Natufian (15-13 kyr BP) living surfaces, dwellings and burials. Using FTIR, we investigated the environmental factors that influenced the preservation of material for radiocarbon dating of the site, and we tested a modified pre-treatment method for poorly preserved charcoal samples. We found that the usual pre-treatment protocol for C-14 samples (W-ABA) removed more charcoal material than the method modified by Rebollo et al. (2008) which omits the first acid treatment (W-BA). This first acid step enhanced the extraction of humic substances during the subsequent base step. The modified W-BA method is a promising tool for dating poorly preserved charcoals which needs further testing with

  13. Landscape evolution reconstructions on Mars: a detailed analysis of lacustrine and fluvial terraces (United States)

    Rossato, Sandro; Pajola, Maurizio; Baratti, Emanuele; Mangili, Clara; Coradini, Marcello


    Liquid water was flowing on the surface of Mars in the past, leaving behind a wide range of geomorphic features. The ancient major Martian water fluxes vanished about 3.5 Ga. Meteoritic impacts, wind-erosion, gravity-related phenomena, tectonic deformations and volcanic activities deeply altered the landforms during the ages. Hence, the reconstruction of water-shaped landscapes is often complicated. Fluvial and lacustrine terraces analysis and correlation is a useful approach to understand and reconstruct the past changes in Martian landscape evolution. These features are commonly used as reference for the top of water bodies on Earth, since they are void of the uncertainties or errors deriving from erosional or slumping processes that could have acted on the valley flanks or in the plateau, where the hydrological network was carved in. The study area is located in the western hemisphere of Mars, in the Memnonia quadrangle, between latitude 9° 10'-9° 50'South and longitude 167° 0'-167° 30' West and it constitutes a transition region between the southern highlands of Terra Sirenum and the northern lowlands of Lucus Planum. Many water-shaped features have already been described near the study area, the most prominent of them being the Ma'adim Vallis and the Mangala Valles system. Our results derive from the observations and the analysis of HRSC images (12.5 m spatial resolution) and Digital Elevation Models (DEMs) derived from the MEX-HRSC (75 m resolution), that allow the identification of elevation differences up to the tens of meter scale. We were able to reconstruct six main evolutionary stages of a complex hydrologic systems consisting of two main palaeorivers (up to 5 km wide) connected one another by a palaeolake that formed within a meteor crater (~20 km diameter). On the basis of Earth analogs, these stages/terraces should have evolved during a long period of time, at least thousands years long. Furthermore, crater counting date back the deactivation of

  14. The characterization of twenty sequenced human genomes.

    Directory of Open Access Journals (Sweden)

    Kimberly Pelak


    Full Text Available We present the analysis of twenty human genomes to evaluate the prospects for identifying rare functional variants that contribute to a phenotype of interest. We sequenced at high coverage ten "case" genomes from individuals with severe hemophilia A and ten "control" genomes. We summarize the number of genetic variants emerging from a study of this magnitude, and provide a proof of concept for the identification of rare and highly-penetrant functional variants by confirming that the cause of hemophilia A is easily recognizable in this data set. We also show that the number of novel single nucleotide variants (SNVs discovered per genome seems to stabilize at about 144,000 new variants per genome, after the first 15 individuals have been sequenced. Finally, we find that, on average, each genome carries 165 homozygous protein-truncating or stop loss variants in genes representing a diverse set of pathways.

  15. Pluripotency of embryo-derived stem cells from rodents, lagomorphs, and primates: Slippery slope, terrace and cliff. (United States)

    Savatier, Pierre; Osteil, Pierre; Tam, Patrick P L


    The diverse cell states and in vitro conditions for the derivation and maintenance of the mammalian embryo-derived pluripotent stem cells raise the questions of whether there are multiple states of pluripotency of the stem cells of each species, and if there are innate species-specific variations in the pluripotency state. We will address these questions by taking a snapshot of our knowledge of the properties of the pluripotent stem cells, focusing on the maintenance of pluripotency and inter-conversion of the different types of pluripotent stem cells from rodents, lagomorphs and primates. We conceptualize pluripotent stem cells acquiring a series of cellular states represented as terraces on a slope of descending gradient of pluripotency. We propose that reprogramming pluripotent stem cells from a primed to a naive state is akin to moving upstream over a steep cliff to a higher terrace. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  16. Content of heavy metals in gleyic chernozem of Srem loess terrace under alfalfa

    Directory of Open Access Journals (Sweden)

    Jakšić Snežana


    Full Text Available Production of high-quality forage from alfalfa is influenced not only by the presence of nutrients, but also by the absence of harmful elements, such as heavy metals. The examination of the total heavy metals content (Ni, Cr, Pb and As in gleyic chernozem soil of Srem loess terrace in Hrtkovci, under alfalfa (Medicago sativa L. were carried out in 2011 in order to determine suitability for the production of safe forage. It total content of Pb, As and Crwas below the maximum permitted concentrations. The content of As, Cr and Ni was higher in the surface layer, unlike Pb, whose content was higher in the deeper layers of soil. A significant positive correlation was found between the total content of Ni, Cr and As. An increased concentration of Ni was found, which was above the maximum permitted concentration. It is necessary to further control its content and accessibility examination and extraction from plants, to prevent its entry into the food chain and provide safe food.

  17. Raman and SEM analysis of a biocolonised hot spring travertine terrace in Svalbard, Norway

    Directory of Open Access Journals (Sweden)

    Jorge-Villar Susana E


    Full Text Available Abstract Background A profile across 8 layers from a fossil travertine terrace from a low temperature geothermal spring located in Svalbard, Norway has been studied using both Raman spectroscopy and SEM (Scanning Electron Microscopy techniques to identify minerals and organic life signals. Results Calcite, anatase, quartz, haematite, magnetite and graphite as well as scytonemin, three different carotenoids, chlorophyll and a chlorophyll-like compound were identified as geo- and biosignatures respectively, using 785 and/or 514 nm Raman laser excitation wavelengths. No morphological biosignatures representing remnant microbial signals were detected by high-resolution imaging, although spectral analyses indicated the presence of organics. In contrast, in all layers, Raman spectra identified a series of different organic pigments indicating little to no degradation or change of the organic signatures and thus indicating the preservation of fossil biomarker compounds throughout the life time of the springs despite the lack of remnant morphological indicators. Conclusion With a view towards planetary exploration we discuss the implications of the differences in Raman band intensities observed when spectra were collected with the different laser excitations. We show that these differences, as well as the different detection capability of the 785 and 514 nm laser, could lead to ambiguous compound identification. We show that the identification of bio and geosignatures, as well as fossil organic pigments, using Raman spectroscopy is possible. These results are relevant since both lasers have been considered for miniaturized Raman spectrometers for planetary exploration.

  18. The Tarawera eruption, Lake Rotomahana, and the origin of the Pink and White Terraces (United States)

    Keam, Ronald F.


    This chapter introduces the historical and geographical background for the scientific studies at Tarawera and Lake Rotomahana in the Taupo Volcanic Zone of New Zealand as detailed in this Special Issue of the Journal of Volcanology and Geothermal Research. It also presents the results of some original investigations. These are based partly on the large body of historical information that exists about the 1886 Tarawera eruption and the geothermal system at Rotomahana, and partly on the results of dedicated geological studies by other researchers within the Okataina Volcanic Centre where the historical events took place. Specifically, the new material here presented includes a detailed analysis of a previously almost neglected narrative by the only observer to witness the 1886 eruption from the southeast of the erupting craters and leave an account of his observations. The importance of a co-operative interplay between pre-existing tectonic deformation and its responses to strong seismic activity induced by magmatic intrusion is emphasised as being a major determinant in the course of the eruption, and as the main trigger of the eruption explosions that were audible throughout half of the land area of New Zealand. The chapter then concentrates on showing how the recent geological studies, in conjunction with ideas on the architecture of geysers, permit an explanation to be given as to how the unique Pink and White Terraces came to be formed.

  19. Developing a Luminescence Chronology for Fan-terrace Sediments, Los Cabos, Baja California, Mexico (United States)

    Rhodes, E. J.; Brown, N. D.; Antinao, J.; Huenupi, E. C.; Baker, S. E.; McDonald, E.


    Extensive depositional units forming large terrace units within alluvial fans close to the southern tip of Baja California, Mexico, record sedimentation under a very different climatic regime from the present. Dating these sediments presents significant challenges; they contain very sparse organic material suitable for radiocarbon dating; their upper surfaces are heavily bioturbated, in some places eroded and in other locations show signs of continued deposition even after incision and base level fall, rendering them difficult to date using TCN (terrestrial cosmogenic nuclide) methods. Locations that have experienced significant regional tectonic influences associated with rapid erosion (e.g. Transverse Ranges, California, Southern Alps, New Zealand, Himalaya and Tibet) are typically not well-suited for quartz OSL (optically stimulated luminescence) application owing to low signal sensitivity. For this reason, our efforts to develop a chronology for the sandy sediments that characterize these contexts have focussed on IRSL dating of K-feldspar, using newly developed post-infrared IRSL (infra-red stimulated luminescence) approaches. We explore the relative advantages of different techniques, and methods to assess both the degree of incomplete zeroing and signal fading. In particular, we explore how novel single grain IRSL measurements of K-feldspar can be applied to these and similar high energy deposits on timescales ranging from the last 100,000 years to a few decades. Based on our chronology coupled with detailed sedimentological and soil stratigraphy investigations, we are able to exploit these deposits as valuable archives of past environmental and climatic change.

  20. Contested Rivers

    DEFF Research Database (Denmark)

    Gorm Hansen, Louise Lyngfeldt

    explores translocal connections through ethnographic fieldwork at a global water conference and preliminary fieldwork at chosen locations on China's Nu River. The Nu River is one of the last undammed rivers in Asia and runs through China close to the Chinese-Burmese border, then flows into the Andaman Sea...

  1. Industrial Agglomeration, Technological Change and Total Factor Productivity---Based on the Empirical Analysis of Twenty Manufacturing Industries in Yangtze River Delta%产业集聚、技术变化与全要素生产率--基于长三角20个制造行业的实证分析

    Institute of Scientific and Technical Information of China (English)

    金飞; 陈晓峰


    本文通过非参数DEA-Malmquist指数法估算了2003~2012年间长三角20个制造业行业的全要素生产率(TFP),并借鉴EG和MS的分类,将Malmquist指数分解为技术进步指数和技术效率指数,分析不同集聚程度行业对它们的影响及其变化趋势,在此基础上借用Arellano和Bond的动态面板模型,验证技术进步和技术效率指数在TFP增长过程中的贡献。实证结果表明:制造业集聚一定程度上促进了整体TFP的提高,但主要是通过促进技术进步(并非促进技术效率改进)进而产生影响。各细分行业TFP增长率存在较大差异,中低度集聚行业的TFP的增长率大于高度集聚行业,并且随着时间推移,高集聚度行业TFP增长率逐渐下降。而且,技术进步和技术创新将是长三角制造业TFP增长的重要推动力。%Industrial agglomeration playing an important role in promoting TFP has reached a consensus , but there is debate on the mechanism of action of different industries and regional levels . This paper estimates by non -parametric DEA -Malmquist TFP index method of the Yangtze River Delta , 20 manufacturing industries from 2003 to 2012 , and learns from EG and MS classification , and the Malmquist index is decomposed into technological progress and technical efficiency index , analysis of different clustering the extent of their impact on the industry , on the basis of the aid Arellano and Bond dynamic panel model to verify the contribution of technological progress and technical efficiency index index in TFP growth process . The empirical results show that :the Yangtze River Delta manufacturing cluster to some extent contributed to improving the overall TFP , but mainly through the impact of technological advances to improve TFP , rather than to promote technical efficiency occurred . There is a big difference between the various sub -sectors in TFP growth :the growth rate in the low

  2. Faulted terrace risers place new constraints on the late Quaternary slip rate for the central Altyn Tagh fault, northwest Tibet (United States)

    Gold, R.D.; Cowgill, E.; Arrowsmith, J.R.; Chen, X.; Sharp, W.D.; Cooper, K.M.; Wang, X.-F.


    The active, left-lateral Altyn Tagh fault defines the northwestern margin of the Tibetan Plateau in western China. To clarify late Quaternary temporal and spatial variations in slip rate along the central portion of this fault system (85??-90??E), we have more than doubled the number of dated offset markers along the central Altyn Tagh fault. In particular, we determined offset-age relations for seven left-laterally faulted terrace risers at three sites (Kelutelage, Yukuang, and Keke Qiapu) spanning a 140-km-long fault reach by integrating surficial geologic mapping, topographic surveys (total station and tripod-light detection and ranging [T-LiDAR]), and geochronology (radiocarbon dating of organic samples, 230Th/U dating of pedogenic carbonate coatings on buried clasts, and terrestrial cosmogenic radionuclide exposure age dating applied to quartz-rich gravels). At Kelutelage, which is the westernmost site (37.72??N, 86.67??E), two faulted terrace risers are offset 58 ?? 3 m and 48 ?? 4 m, and formed at 6.2-6.1 ka and 5.9-3.7 ka, respectively. At the Yukuang site (38.00??N, 87.87??E), four faulted terrace risers are offset 92 ?? 12 m, 68 ?? 6 m, 55 ?? 13 m, and 59 ?? 9 m and formed at 24.2-9.5 ka, 6.4-5.0 ka, 5.1-3.9 ka, and 24.2-6.4 ka, respectively. At the easternmost site, Keke Qiapu (38.08??N, 88.12??E), a faulted terrace riser is offset 33 ?? 6 m and has an age of 17.1-2.2 ka. The displacement-age relationships derived from these markers can be satisfied by an approximately uniform slip rate of 8-12 mm/yr. However, additional analysis is required to test how much temporal variability in slip rate is permitted by this data set. ?? 2011 Geological Society of America.

  3. Emerged quaternary marine terraces in southern Peru: Sea level changes and continental margin tectonics over the subducting Nazca Ridge

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, J.T.J.


    Because of the arid climate, mollusk shells in the marine cover strata are exceptionally well preserved and provide datable samples for a terrace and sea level chronology. Amino acid racemization was the most extensively used dating method, with three other numerical dating methods, electron spin resonance (ESR), Uranium-series, and radiocarbon ages used to calibrate the amino acid ages. D-alloisoleucine/L-isoleucine (A/I) ratios of >200 mollusks shells belong to six statistically and geomorphically defined aminozones. Aminozone IIa correlates with the last Interglacial (deep-sea oxygen isotope Stage 5e) based on 12 ESR ages and the similarity of the IIa ratios to those determined from calibrated last Interglacial sites on the Pacific Coast, U.S. Calibrated amino acid ages for the other aminozones are; I = >45,000 yr B.P. and {le} 87,000; IIb = 211,000 yr B.P.; III = 297,000 yr B.P.; IV = 496,000 yr B.P.; and V {ge} 945,000 yr B.P. The calibrated ages agree with ESR, Uranium series, and radioactive ages. The pattern of terrace deformation can be approximated by a simple geometric model in which the subconducting Nazca Ridge migrates obliquely southeastward as a rigid trapezoid beneath the forearc. The model correctly predicts a pattern of marine terrace deformation with the highest elevations located above the southern flank of the Nazca Ridge and subsidence above the northern flank. The topography, pattern of marine terrace deformation, and Quaternary rates of uplift of the Paracas Block are determined by oblique subduction of the aseismic Nazca Ridge.

  4. Why (1 0 0) terraces break and make bonds: oxidation of dimethyl ether on platinum single-crystal electrodes. (United States)

    Li, Hongjiao; Calle-Vallejo, Federico; Kolb, Manuel J; Kwon, Youngkook; Li, Yongdan; Koper, Marc T M


    A surface structural preference for (1 0 0) terraces of fcc metals is displayed by many bond-breaking or bond-making reactions in electrocatalysis. Here, this phenomenon is explored in the electrochemical oxidation of dimethyl ether (DME) on platinum. The elementary C-O bond-breaking step is identified and clarified by combining information obtained from single-crystal experiments and density functional theory (DFT) calculations. Experiments on Pt(1 0 0), Pt(5 1 0), and Pt(10 1 0) surfaces show that the surface structure sensitivity is due to the bond-breaking step, which is unfavorable on step sites. DFT calculations suggest that the precursor for the bond-breaking step is a CHOC adsorbate that preferentially adsorbs on a square ensemble of four neighboring atoms on Pt(1 0 0) terraces, named as "the active site". Step sites fail to strongly adsorb CHOC and are, therefore, ineffective in breaking C-O bonds, resulting in a decrease in activity on surfaces with increasing step density. Our combined experimental and computational results allow the formulation of a new mechanism for the electro-oxidation of DME as well as a simple general formula for the activity of different surfaces toward electrocatalytic reactions that prefer (1 0 0) terrace active sites.

  5. Implementing automatic LiDAR and supervised mapping methodologies to quantify agricultural terraced landforms at landscape scale: the case of Veneto Region (United States)

    Eugenio Pappalardo, Salvatore; Ferrarese, Francesco; Tarolli, Paolo; Varotto, Mauro


    Traditional agricultural terraced landscapes presently embody an important cultural value to be deeply investigated, both for their role in local heritage and cultural economy and for their potential geo-hydrological hazard due to abandonment and degradation. Moreover, traditional terraced landscapes are usually based on non-intensive agro-systems and may enhance some important ecosystems services such as agro-biodiversity conservation and cultural services. Due to their unplanned genesis, mapping, quantifying and classifying agricultural terraces at regional scale is often critical as far as they are usually set up on geomorphologically and historically complex landscapes. Hence, traditional mapping methods are generally based on scientific literature and local documentation, historical and cadastral sources, technical cartography and aerial images visual interpretation or, finally, field surveys. By this, limitations and uncertainty in mapping at regional scale are basically related to forest cover and lack in thematic cartography. The Veneto Region (NE of Italy) presents a wide heterogeneity of agricultural terraced landscapes, mainly distributed within the hilly and Prealps areas. Previous studies performed by traditional mapping method quantified 2,688 ha of terraced areas, showing the higher values within the Prealps of Lessinia (1,013 ha, within the Province of Verona) and in the Brenta Valley (421 ha, within the Province of Vicenza); however, terraced features of these case studies show relevant differences in terms of fragmentation and intensity of terraces, highlighting dissimilar degrees of clusterization: 1.7 ha on one hand (Province of Verona) and 1.2 ha per terraced area (Province of Vicenza) on the other one. The aim of this paper is to implement and to compare automatic methodologies with traditional survey methodologies to map and assess agricultural terraces in two representative areas of the Veneto Region. Testing different Remote Sensing

  6. Preliminary study on the influence of coal mining on river runoff (United States)

    Zhang, N.; Jiang, H.; Guo, X. W.; Yin, H. J.; Su, X. H.


    Coal mining is a major cause of decreases in river runoff, which can increase the disparity between the supply and demand of water resources. This paper presents runoff variation data from Tou-Tong to analyze the impacts of rainfall and human activity on runoff. This data showed that the annual runoff of Gushanchuan, Kuye and Tuwei river decreased significantly in the middle and latter half of the 1990s. Reservoirs, key dams, terraced fields and vegetation variation are all important factors that affect decreases in runoff. The effect of three types of coal mining on the water cycle is put forward and quantitatively calculated.

  7. Automatic identification of agricultural terraces through object-oriented analysis of very high resolution DSMs and multispectral imagery obtained from an unmanned aerial vehicle. (United States)

    Diaz-Varela, R A; Zarco-Tejada, P J; Angileri, V; Loudjani, P


    Agricultural terraces are features that provide a number of ecosystem services. As a result, their maintenance is supported by measures established by the European Common Agricultural Policy (CAP). In the framework of CAP implementation and monitoring, there is a current and future need for the development of robust, repeatable and cost-effective methodologies for the automatic identification and monitoring of these features at farm scale. This is a complex task, particularly when terraces are associated to complex vegetation cover patterns, as happens with permanent crops (e.g. olive trees). In this study we present a novel methodology for automatic and cost-efficient identification of terraces using only imagery from commercial off-the-shelf (COTS) cameras on board unmanned aerial vehicles (UAVs). Using state-of-the-art computer vision techniques, we generated orthoimagery and digital surface models (DSMs) at 11 cm spatial resolution with low user intervention. In a second stage, these data were used to identify terraces using a multi-scale object-oriented classification method. Results show the potential of this method even in highly complex agricultural areas, both regarding DSM reconstruction and image classification. The UAV-derived DSM had a root mean square error (RMSE) lower than 0.5 m when the height of the terraces was assessed against field GPS data. The subsequent automated terrace classification yielded an overall accuracy of 90% based exclusively on spectral and elevation data derived from the UAV imagery.

  8. Uplifted marine terraces in Davao Oriental Province, Mindanao Island, Philippines and their implications for large prehistoric offshore earthquakes along the Philippine trench (United States)

    Ramos, Noelynna T.; Tsutsumi, Hiroyuki; Perez, Jeffrey S.; Bermas, Percival P.


    We conducted systematic mapping of Holocene marine terraces in eastern Mindanao Island, Philippines for the first time. Raised marine platforms along the 80-km-long coastline of eastern Davao Oriental Province are geomorphic evidence of tectonic deformation resulting from the westward subduction of the Philippine Sea plate along the Philippine trench. Holocene coral platforms consist of up to four terrace steps: T1: 1-5 m, T2: 3-6 m, T3: 6-10 m, and T4: 8-12 m amsl, from the lowest to highest, respectively. Terraces are subhorizontal, exposing cemented coral shingle and eroded coral heads, while terrace risers are 1-3 m high. Radiocarbon ages, 8080-4140 cal yr BP, reveal that erosional surfaces were carved onto the Holocene transgressive reef complex which grew upward until ˜8000 years ago. The maximum uplift rate is ˜1.5 mm/yr based on the highest Holocene terrace at Philippine trench were not large enough to produce meter-scale coastal uplift, suggesting that much larger earthquakes occurred in the past. A long-term tectonic uplift rate of ˜1.3 mm/yr was also estimated based on Late Pleistocene terraces.

  9. The twenty-first century in space

    CERN Document Server

    Evans, Ben


    This final entry in the History of Human Space Exploration mini-series by Ben Evans continues with an in-depth look at the latter part of the 20th century and the start of the new millennium. Picking up where Partnership in Space left off, the story commemorating the evolution of manned space exploration unfolds in further detail. More than fifty years after Yuri Gagarin’s pioneering journey into space, Evans extends his overview of how that momentous voyage continued through the decades which followed. The Twenty-first Century in Space, the sixth book in the series, explores how the fledgling partnership between the United States and Russia in the 1990s gradually bore fruit and laid the groundwork for today’s International Space Station. The narrative follows the convergence of the Shuttle and Mir programs, together with standalone missions, including servicing the Hubble Space Telescope, many of whose technical and human lessons enabled the first efforts to build the ISS in orbit. The book also looks to...

  10. Twenty Years After: Armenian Research Libraries Today

    Directory of Open Access Journals (Sweden)

    D. Aram Donabedian


    Full Text Available Since achieving statehood in 1991, Armenia has faced major economic and political obstacles which have significantly affected the nation’s research libraries. This research paper will quantitatively and qualitatively examine the challenges facing Armenian research libraries just over twenty years after the collapse of the Soviet Union. Specifically, the authors analyze their interviews with five library administrators at five major institutions, respectively. These include Yerevan State University Library, the National Library of Armenia, the Fundamental Scientific Library of the National Academy of Sciences of Armenia, the Republican Scientific-Medical Library of Armenia, and the Papazian Library of the American University of Armenia. The instrument for the interviews consists of 73 questions based on the 2004 Association of College and Research Libraries Standards for Libraries in Higher Education and evaluates the following factors:• The library’s mission, goals and objectives• Public or user services• Instruction activities at the library• Resources (print, media, or electronic and collection development• Access to the library’s resources• Outcome assessment, or evaluation of the library• Staffing issues• Facility maintenance and plans for library development• Communication and cooperation both within the library and with the user community• Administration• BudgetIn addition, we will focus on the strengths and weaknesses of these libraries and investigate the growing open access movement in Armenia. Based on our findings, the authors wish to facilitate dialogue and consider possible approaches to help these libraries meet Armenia’s pressing information needs.

  11. Landslide Susceptibility Evaluation on agricultural terraces of DOURO VALLEY (PORTUGAL), using physically based mathematical models. (United States)

    Faria, Ana; Bateira, Carlos; Laura, Soares; Fernandes, Joana; Gonçalves, José; Marques, Fernando


    The work focuses the evaluation of landslide susceptibility in Douro Region agricultural terraces, supported by dry stone walls and earth embankments, using two physically based models. The applied models, SHALSTAB (Montgomery et al.,1994; Dietrich et al., 1995) and SINMAP (PACK et al., 2005), combine an infinite slope stability model with a steady state hydrological model, and both use the following geophysical parameters: cohesion, friction angle, specific weight and soil thickness. The definition of the contributing areas is different in both models. The D∞ methodology used by SINMAP model suggests a great influence of the terraces morphology, providing a much more diffuse flow on the internal flow modelling. The MD8 used in SHALSTAB promotes an important degree of flow concentration, representing an internal flow based on preferential paths of the runoff as the areas more susceptible to saturation processes. The model validation is made through the contingency matrix method (Fawcett, 2006; Raia et al., 2014) and implies the confrontation with the inventory of past landslides. The True Positive Rate shows that SHALSTAB classifies 77% of the landslides on the high susceptibility areas, while SINMAP reaches 90%. The SINMAP has a False Positive Rate (represents the percentage of the slipped area that is classified as unstable but without landslides) of 83% and the SHALSTAB has 67%. The reliability (analyzes the areas that were correctly classified on the total area) of SHALSTAB is better (33% against 18% of SINMAP). Relative to Precision (refers to the ratio of the slipped area correctly classified over the whole area classified as unstable) SHALSTAB has better results (0.00298 against 0.00283 of SINMAP). It was elaborate the index TPR/FPR and better results obtained by SHALSTAB (1.14 against 1.09 of SINMAP). SHALSTAB shows a better performance in the definition of susceptibility most prone areas to instability processes. One of the reasons for the difference of

  12. Agricultural terraces montoring and modeling: a field survey in Chianti region, Firenze, Italy – Second part (United States)

    Preti, Federico; Caruso, Marco; Dani, Andrea; Cassiani, Giorgio; Romano, Nunzio; Tarolli, Paolo


    The two abstracts present the design and set-up of an experimental campaign which aims at sup-porting the modeling (conceptual and numerical) of water circulation in a terraced slope, and its in-fluence on stability of retaining dry stone walls. The case study is located at "Fattoria di Lamole" (Greve in Chianti, Firenze, Italy). At Lamole site both ancient and recently restored or rebuilt (with different techniques) dry stone walls are present. Furthermore the intense vineyards cultivation makes it very representative in terms of range of external stresses that affect both hillslopes and wall. The survey is developed within the bigger framework of landscape preservation as a way to prevent hydrogeological instabilities and landslide risks. Second Part A second effort is devoted to couple hydrological, hydraulic and geotechnical modeling: - Flow directions and the drainage area have been derived from DTM (high-resolution digital terrain model obtained by a terrestrial laser scanner.), and served for the RPII index calcula-tion (Tarolli et al., 2013), that is coherent with the critical spots observed in situ and marked with GPS. - Direct shear test on undisturbed and reconstituted soil samples will offer an estimation of the Mohr-Coulomb failure envelope parameters (friction angle and cohesion). - Retention curves related with different depths have been derived. - Geoelectric analysis in order to locate the bedrock and to determine the subterranean water flows originated from controlled infitration tests (1 l/s discharge). - A simple dry-wall stability model has been carried out; this model analyses the wall stability with finite elements method, evaluating pressures derived from uphill water infiltration, stone friction and buoyancy in retaining wall layers: simulated deformation are suitable with the observed ones. Acknowledgements Italian Research Project of Relevant Interest (PRIN2010-2011), prot. 20104ALME4, National network for monitoring, modeling, and

  13. Evaluation of soil carbon pools after the addition of prunings in subtropical orchards placed in terraces (United States)

    Márquez San Emeterio, Layla; Martín Reyes, Marino Pedro; Ortiz Bernad, Irene; Fernández Ondoño, Emilia; Sierra Aragón, Manuel


    The amount of carbon that can be stored in a soil depends on many factors, such as the type of soil, the chemical composition of plant rests and the climate, and is also highly affected by land use and soil management. Agricultural ecosystems are proved to absorb a large amount of CO2 from the atmosphere through several sustainable management practices. In addition, organic materials such as leaves, grass, prunings, etc., comprise a significant type of agricultural practices as a result of waste recycling. The aim of this research was to evaluate the effects of the addition of different organic prunings on the potential for carbon sequestration in agricultural soils placed in terraces. Three subtropical orchards were sampled in Almuñécar (Granada, S Spain): mango (Mangifera indica L.), avocado (Persea americana Mill.) and cherimoya (Annonacherimola Mill.). The predominant climate is Subtropical Mediterranean and the soil is an Eutric Anthrosol. The experimental design consisted in the application of prunings from avocado, cherimoya and mango trees, placed on the surface soil underneath their correspondent trees, as well as garden prunings from the green areas surrounding the town center on the surface soils under the three orchard trees. Control experiences without the addition of prunings were also evaluated. These experiences were followed for three years. Soil samples were taken at4 cm depth. They were dried for 3-4 days and then sieved (orchard. Our findings suggest that the addition of prunings and other organic debris may be a very useful practice for increasing the content of organic matter within the surface soil layer. Acknowledgements Authors thank the financial support of this work to the Spanish Ministry of Economy and Competitiveness (Project CGL-2013-46665-R) and the European Regional Development Fund (ERDF).

  14. Housing Space Quality towards Quality Of Life: A Case Study of Double Storey Terrace Houses

    Directory of Open Access Journals (Sweden)

    Bakar Aniza Abu


    Full Text Available The success of every housing area is determined by its user satisfaction level, living there. The quality of the house, its spaces within the unit, housing neighbourhood and green open space can directly influence the quality of life. Limitation of space following high land cost in an urban area, evaluation of the housing environment as a whole including the green open space needs to be studied as it affects the residents’ satisfaction level. This study concentrates on spaces within a housing area to evaluate the residents’ level of satisfaction of the Taman Melati Mastika (TMM, Kuala Lumpur and to understand how they perceived their quality of life through the housing environment and the availability of green open space. Thus, this research was carried out through site observation and analysis, and self-administered questionnaire survey. 247 questionnaire surveys were distributed to the residents of TMM and (n=62 responded. When focused on the housing unit, this study provides insight on the types of outdoor spaces (front yard-front lane and backyard-back lane and their elements and utilization, and quality of housing spaces toward users’ quality of life in TMM, Kuala Lumpur. On the green open space, the assessment of the quality of life is based on three factors that are the safety level of the neighbourhood and park, health issues related to housing environment and park as well as the satisfaction on the housing amenities and park facilities. The result of this study suggests that the residents are satisfied with the existing spaces within their compound and adjacent to it and this lead towards the overall satisfaction living in the area. The quality of space and good utilisation of housing areas can lead towards a better quality of life in the Terrace housing area is confirmed.

  15. Analysing the role of abandoned agricultural terraces on flood generation in a set of small Mediterranean mountain research catchments (Vallcebre, NE Spain) (United States)

    Gallart, Francesc; Llorens, Pilar; Pérez-Gallego, Nuria; Latron, Jérôme


    The Vallcebre research catchments are located in NE Spain, in a middle mountain area with a Mediterranean sub-humid climate. Most of the bedrock consists of continental red lutites that are easily weathered into loamy soils. This area was intensely used for agriculture in the past when most of the sunny gentle hillslopes were terraced. The land was progressively abandoned since the mid-20th Century and most of the fields were converted to meadows or were spontaneously forested. Early studies carried out in the terraced Cal Parisa catchment demonstrated the occurrence of two types of frequently saturated areas, ones situated in downslope locations with high topographic index values, and the others located in the inner parts of many terraces, where the shallow water table usually outcrops due to the topographical modifications linked to terrace construction. Both the increased extent of saturated areas and the role of a man-made elementary drainage system designed for depleting water from the terraces suggested that terraced areas would induce an enhanced hydrological response during rainfall events when compared with non-terraced hillslopes. The response of 3 sub-catchments, of increasing area and decreasing percentage of terraced area, during a set of major events collected during over 15 years has been analysed. The results show that storm runoff depths were roughly proportional to precipitations above 30 mm although the smallest catchment (Cal Parisa), with the highest percentage of terraces, was able to completely buffer rainfall events of 60 mm in one hour without any runoff when antecedent conditions were dry. Runoff coefficients depended on antecedent conditions and peak discharges were weakly linked to rainfall intensities. Peak lag times, peak runoff rates and recession coefficients were similar in the 3 catchments; the first variable values were in the range between Hortonian and saturation overland flow and the two last ones were in the range of

  16. River nomads

    DEFF Research Database (Denmark)


    River nomads is a movie about people on the move. The documentary film explores the lifestyle of a group of nomadic fishermen whose mobility has been the recipe of success and troubles. Engaged in trade and travel, twice a year the river nomads form impressive convoys of majestic pirogues and set...... and liberated lifestyle and the breath-taking landscapes and vistas offered by the Niger River. River Nomads is also a personal account of the Kebbawa’s way of life and their current struggles as nomadic folk living in a world divided by borders and ruled by bureaucrats....

  17. Contingency table analysis of pebble lithology and roundness: A case study of Huangshui River, China and comparison to rivers in the Rocky Mountains, USA (United States)

    Miao, Xiaodong; Lindsey, David A.; Lai, Zhongping; Liu, Xiaodong


    Contingency table analysis of pebble lithology and roundness is an effective way to identify the source terrane of a drainage basin and to distinguish changes in basin size, piracy, tectonism, and other events. First, the analysis to terrace gravel deposited by the Huangshui River, northeastern Tibet Plateau, China, shows statistically contrasting pebble populations for the oldest terrace (T7, Dadongling, 1.2 Ma) and the youngest terraces (T0-T3, ≤ 0.15 Ma). Two fluvial processes are considered to explain the contrast in correlation between lithology and roundness in T7 gravel versus T0-T3 gravel: 1) reworking of T7 gravel into T0-T3 gravel and 2) growth in the size of the river basin between T7 and T0-T3 times. We favor growth in basin size as the dominant process, from comparison of pebble counts and contingency tables. Second, comparison of results from Huangshui River of China to three piedmont streams of the Rocky Mountains, USA highlights major differences in source terrane and history. Like Rocky Mountain piedmont gravel from Colorado examples, the Huangshui gravels show a preference (observed versus expected frequency) for rounded granite. But unlike Rocky Mountain gravel, Huangshui gravel shows a preference for angular quartzite and for rounded sandstone. In conclusion, contrasting behavior of lithologies during transport, not always apparent in raw pebble counts, is readily analyzed using contingency tables to identify the provenance of individual lithologies, including recycled clasts. Results of the analysis may help unravel river history, including changes in basin size and lithology.

  18. A multidating approach applied to historical slackwater flood deposits of the Gardon River, SE France (United States)

    Dezileau, L.; Terrier, B.; Berger, J. F.; Blanchemanche, P.; Latapie, A.; Freydier, R.; Bremond, L.; Paquier, A.; Lang, M.; Delgado, J. L.


    A multidating approach was carried out on slackwater flood deposits, preserved in valley side rock cave and terrace, of the Gardon River in Languedoc, southeast France. Lead-210, caesium-137, and geochemical analysis of mining-contaminated slackwater flood sediments have been used to reconstruct the history of these flood deposits. These age controls were combined with the continuous record of Gardon flow since 1890, and the combined records were then used to assign ages to slackwater deposits. The stratigraphic records of terrace GE and cave GG were excellent examples to illustrate the effects of erosion/preservation in a context of a progressively self-censoring, vertically accreting sequence. The sedimentary flood record of the terrace GE located at 10 m above the channel bed is complete for years post-1958 but incomplete before. During the 78-year period 1880-1958, 25 floods of a sufficient magnitude (> 1450 m3/s) have covered the terrace. Since 1958, however, the frequency of inundation of the deposits has been lower: only 5 or 6 floods in 52 years have been large enough to exceed the necessary threshold discharge (> 1700 m3/s). The progressive increase of the threshold discharge and the reduced frequency of inundation at the terrace could allow stabilization of the vegetation cover and improve protection against erosion from subsequent large magnitude flood events. The sedimentary flood record seems complete for cave GG located at 15 m above the channel bed. Here, the low frequency of events would have enabled a high degree of stabilization of the sedimentary flood record, rendering the deposits less susceptible to erosion. Radiocarbon dating is used in this study and compared to the other dating techniques. Eighty percent of radiocarbon dates on charcoals were considerably older than those obtained by the other techniques in the terrace. On the other hand, radiocarbon dating on seeds provided better results. This discrepancy between radiocarbon dates on

  19. Proceedings: Twenty years of energy policy: Looking toward the twenty-first century

    Energy Technology Data Exchange (ETDEWEB)


    In 1973, immediately following the Arab Oil Embargo, the Energy Resources Center, University of Illinois at Chicago initiated an innovative annual public service program called the Illinois Energy Conference. The objective was to provide a public forum each year to address an energy or environmental issue critical to the state, region and nation. Twenty years have passed since that inaugural program, and during that period we have covered a broad spectrum of issues including energy conservation nuclear power, Illinois coal, energy policy options, natural gas, alternative fuels, new energy technologies, utility deregulation and the National Energy Strategy.

  20. Data report for the geologic and scenic quality evaluation of selected sand and gravel sites on the Wind River Indian Reservation, Wyoming (United States)

    Langer, William H.; Van Gosen, Bradley S.; Arbogast, Belinda; Lindsey, David A.


    In April 2005, the U.S. Geological Survey (USGS) conducted field studies on the Wind River Indian Reservation, Wyoming, to inventory and evaluate sand and gravel deposits underlying river terraces on tribal lands along the Wind River. This report contains the results for 12 sites of sand and gravel deposits evaluated for their potential use as aggregate in Portland cement concrete, asphalt, and base course. The report provides the results of: * The USGS geologic studies and engineering tests. * A conclusion and recommendation for the best use of sand and gravel materials. * Calculations of available sand and gravel materials. * A scenic quality landscape inventory and evaluation.

  1. Survey of ancient river trace in Hotta stockade site using vertical electrical method; Denki tansa (suichoku tansa) ni yoru futsudenssaku sekinei no kasenseki chosa

    Energy Technology Data Exchange (ETDEWEB)

    Nishitani, Tadasho; Takano, Kasumi; Matsuno, Katsutoshi [Akita University, Akita (Japan); Kodama, Jun


    The vertical electric prospecting was carried out at a high density to investigate the characteristics of ancient river trace in Hotta stockade site, and therefore the ancient river trace at the final stage, the distribution of sand soil and gravel layers due to flooding were clarified. It has been known that the rive terrace was roughly divided into two and merged into one near the government office trace. When estimating the river trace at the final stage, it was also found that the watercourse was divided into two on the east side. It was considered that there were two watercourses existing simultaneously or the watercourse had changed and moved. (translated by NEDO)

  2. Luminescence characteristics of quartz and feldspar from tectonically uplifted terraces in Kashmir Basin, Jammu and Kashmir, India

    Energy Technology Data Exchange (ETDEWEB)

    Jaiswal, Manoj K. [Department of Geosciences, National Taiwan University, Roosevelt Road, sec. 4, Taipei, Taiwan (China)], E-mail:; Bhat, M.I.; Bali, B.S.; Ahmad, Shabir [Department of Geology and Geophysics, University of Kashmir, Srinagar, Jammu and Kashmir (India); Chen, Y.G. [Department of Geosciences, National Taiwan University, Roosevelt Road, sec. 4, Taipei, Taiwan (China)


    The Kashmir Valley or the Jhelum basin is an intermontane-basin in NW Himalaya bounded by the Pir Panjal Range in the south and southwest and the Great Himalayan Range in the north and northeast. The valley is marked by active major thrust boundaries in its south and southwestern parts. Remote sensing studies and morphometric analysis suggest neo-tectonic activities and the formation of tectonic terraces due to uplift on the major thrust boundaries in NW Himalayas. The quartz from freshly eroded mountain belts is usually found to show very poor luminescence sensitivity and thus not suitable for optical dating. Similar problems occurred with the quartz from the Srinagar Basin. Due to this, feldspar was selected as a natural dose meter for dating tectonically uplifted terraces in an active and dynamic belt of the NW Himalayas. We report here for the first time the luminescence characteristics of quartz and feldspar minerals from the study area. However, feldspar also shows poor luminescence sensitivity, although enough to perform optical dating. Athermal fading was observed in all the feldspar samples, which was corrected using 'g' values; a large scatter was found in the g values, probably due to intermixing of feldspar grains from varying source rock types and also due to poor luminescence sensitivity. An average g value correction to the mean paleodose was found to agree if compared with the thermo-luminescence date of loess deposit dated earlier. The ages show that the terrace formation started taking place at {approx}100 ka in the southwestern part of the Jhelum basin and continued with pulses at 50 ka and 11 ka towards the northwestern part.

  3. Arctic soil development on a series of marine terraces on central Spitsbergen, Svalbard: a combined geochronology, fieldwork and modelling approach (United States)

    van der Meij, W. Marijn; Temme, Arnaud J. A. M.; de Kleijn, Christian M. F. J. J.; Reimann, Tony; Heuvelink, Gerard B. M.; Zwoliński, Zbigniew; Rachlewicz, Grzegorz; Rymer, Krzysztof; Sommer, Michael


    Soils in Arctic regions currently enjoy attention because of their sensitivity to climate change. It is therefore important to understand the natural processes and rates of development of these soils. Specifically, there is a need to quantify the rates and interactions between various landscape- and soil-forming processes. Soil chronosequences are ideal natural experiments for this purpose. In this contribution, we combine field observations, luminescence dating and soil-landscape modelling to improve and test our understanding of Arctic soil formation. The field site is a Holocene chronosequence of gravelly raised marine terraces in central Spitsbergen. Field observations show that soil-landscape development is mainly driven by weathering, silt translocation, aeolian deposition and rill erosion. Spatial soil variation is mainly caused by soil age, morphological position within a terrace and depth under the surface. Luminescence dating confirmed existing radiocarbon dating of the terraces, which are between ˜ 1.5 and ˜ 13.3 ka old. The soil-landscape evolution model LORICA was used to test our hypothesis that the field-observed processes indeed dominate soil-landscape development. Model results additionally indicated the importance of aeolian deposition as a source of fine material in the subsoil for both sheltered and vegetated trough positions and barren ridge positions. Simulated overland erosion was negligible. Consequently, an un-simulated process must be responsible for creating the observed erosion rills. Dissolution and physical weathering both play a major role. However, using present-day soil observations, the relative contribution of physical and chemical weathering could not be disentangled. Discrepancies between field and model results indicate that soil formation is non-linear and driven by spatially and temporally varying boundary conditions which were not included in the model. To conclude, Arctic soil and landscape development appears to be more

  4. Redesigning Terraced Social Housing in the UK for Flexibility Using Building Energy Simulation with Consideration of Passive Design

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    Hasim Altan


    Full Text Available A chosen case study house forms the basis of this paper, which is a pilot energy-efficient social housing project, completed by one of the largest housing developers in the UK. The main aim of this study is to inform the redesign of flexible energy-efficient housing units. The housing, designed for social tenants, was built by the Accent Group in 2005, using modern construction methods and sustainable materials, based on extensive research from the adaptable and “Grow Home” principles of Avi Friedman as well as open building implementation. The first pilot scheme was designed in collaboration with the Building Energy Analysis Unit at the University of Sheffield, together with the Goddard Wybor Practise, and was a successful housing development with respect to being environmentally friendly and a low-energy design scheme for the UK climate. This paper presents redesigning of flexible terraced housing units, and their performance evaluation, using a building simulation method as well as the passive-house planning package. The aim was to plan a row of terraced houses that can not only utilize a flexible design concept in floor planning layout, but also to reduce energy consumption with a passive design with particular attention paid to material selection. In addition, building simulation work has been carried out with the use of DesignBuilder software for both thermal and energy performance evaluation. The study examines the annual energy performance and comfort conditions in the designed house to be situated in the Northeast of England, UK. A terraced house unit design is considered a flexible home that can adjust to the needs of different tenants for the purpose of achieving a sustainable building under different aspects, such as low energy, low carbon, use of renewables, and low impact materials, with flexibility by design.


    NARCIS (Netherlands)



    We present a mathematical model for the ''river-phenomenon'': striking concentrations of trajectories of ordinary differential equations. This model of ''macroscopic rivers'' is formulated within nonstandard analysis, and stated in terms of macroscopes and singular perturbations. For a subclass, the

  6. The strategies of local farmers' water management and the eco-hydrological effects of irrigation-drainage engineering systems in world heritage of Honghe Hani Rice Terraces (United States)

    Gao, Xuan


    Terraces are built in mountainous regions to provide larger area for cultivation,in which the hydrological and geomorphological processes are impacted by local farmers' water management strategies and are modified by manmade irrigation-drainage engineering systems.The Honghe Hani Rice Terraces is a 1300a history of traditional agricultural landscape that was inscribed in the 2013 World Heritage List.The local farmers had developed systematic water management strategies and built perfect irrigation-drainage engineering systems to adapt the local rainfall pattern and rice farming activities.Through field investigation,interviews,combined with Geographic Information Systems,Remote Sensing images and Global Positioning Systems technology,the water management strategies as well as the irrigation-drainage systems and their impacts on eco-hydrological process were studied,the results indicate:Firstly,the local people created and maintained an unique woodcarving allocating management system of irrigating water over hundreds years,which aids distributing water and natural nutrition to each terrace field evenly,and regularly according to cultivation schedule.Secondly,the management of local people play an essential role in effective irrigation-drainage engineering system.A ditch leader takes charge of managing the ditch of their village,keeping ample amount of irrigation water,repairing broken parts of ditches,dealing with unfair water using issues,and so on.Meanwhile,some traditional leaders of minority also take part in.Thus, this traditional way of irrigation-drainage engineering has bringed Hani people around 1300 years of rice harvest for its eco-hydrological effects.Lastly we discuss the future of Honghe Hani Rice Terraces,the traditional cultivation pattern has been influenced by the rapid development of modern civilization,in which some related changes such as the new equipment of county roads and plastic channels and the water overusing by tourism are not totally

  7. Comparison of planform multi-channel network characteristics of alluvial and bedrock constrained large rivers (United States)

    Carling, P. A.; Meshkova, L.; Robinson, R. A.


    The Mekong River in northern Cambodia is an multi-channel mixed bedrock-alluvial river but it was poorly researched until present. Preliminary study of the Mekong geomorphology was conducted by gathering existing knowledge of its geological and tectonic settings, specific riparian vegetation and ancient alluvial terraces in which the river has incised since the Holocene. Altogether this process has allowed a geomorphological portrait of the river to be composed within the Quaternary context. Following this outline, the planform characteristics of the Mekong River network are compared, using analysis of channel network and islands configurations, with the fluvial patterns of the Orange River (South Africa), Upper Columbia River (Canada) and the Ganga River (India, Bangladesh). These rivers are selected as examples of multi-channel mixed bedrock alluvial, anastomosed alluvial and braided alluvial rivers respectively. Network parameters such as channel bifurcation angles asymmetry, sinuosity, braid intensity and island morphometric shape metrics are compared and contrasted between bedrock and alluvial systems. In addition, regional and local topographic trend surfaces produced for each river planform help explain the local changes in river direction and the degree of anastomosis, and distinguish the bedrock-alluvial rivers from the alluvial rivers. Variations between planform characteristics are to be explained by channel forming processes and in the case of mixed bedrock-alluvial rivers mediated by structural control. Channel metrics (derived at the reach-scale) provide some discrimination between different multi-channel patterns but are not always robust when considered singly. In contrast, island shape metrics (obtained at subreach-scale) allow robust discrimination between alluvial and bedrock systems.

  8. Hillslope terracing effects on the spatial variability of plant development as assessed by NDVI in vineyards of the Priorat region (NE Spain). (United States)

    Martínez-Casasnovas, José A; Ramos, María Concepción; Espinal-Utgés, Sílvia


    The availability of heavy machinery and the vineyard restructuring and conversion plans of the European Union Common Agricultural Policy (Commission Regulation EC no. 1227/2000 of 31 May 2000) have encouraged the restructuring of many vineyards on hillslopes of Mediterranean Europe, through the creation of terraces to favor the mechanization of agricultural work. Terrace construction requires cutting and filling operations that create soil spatial variability, which affects soil properties and plant development. In the present paper, we study the effects of hillslope terracing on the spatial variability of the normalized difference vegetation index (NDVI) in fields of the Priorat region (NE Spain) during 2004, 2005, and 2006. This index was computed from high-resolution remote sensing data (Quickbird-2). Detailed digital terrain models before and after terrace construction were used to assess the earth movements. The results indicate that terracing by heavy machinery induced high variability on the NDVI values over the years, showing significant differences as effect of the cut and fill operations.

  9. Suspended-sediment and fresh-water discharges in the Ob and Yenisey rivers, 1960-1988 (United States)

    Meade, R.H.; Bobrovitskaya, N.N.; Babkin, V.I.


    Of the world's great rivers, the Ob and Yenisey rank among the largest suppliers of fresh water and among the smallest suppliers of suspended sediment to the coastal ocean. Sediment in the middle reaches of the rivers is mobilized from bordering terraces and exchanged between channels and flood plains. Sediment in the lower reaches of these great rivers is deposited and stored (permanently, on a millennial time scale) in flood plains. Sediment discharges, already small under natural conditions, are diminished further by large manmade reservoirs that trap significant proportions of the moving solids. The long winter freeze and sudden spring breakup impose a peakedness in seasonal water runoff and sediment discharge that contrasts markedly with that in rivers of the tropics and more temperate climates. Very little sediment from the Ob and Yenisey rivers is being transported to the open waters of the Arctic Ocean under present conditions.

  10. Geo morphological setting and main technological features of new Middle and Upper Pleistocene sites in the Lower Manzanares River Valley (Madrid, Spain); Contexto geomorfologico y principales rasgos tecnologicos de nuevos yacimientos del Pleistoceno Medio y Superior en el Valle Inferior del Manzanares (Madrid, Espana)

    Energy Technology Data Exchange (ETDEWEB)

    Silva, P. G.; Lopez Recio, M.; Cuartero, F.; Baena, J.; Tapias, F.; Manzano, I.; Martin, D.; Morin, J.; Roquero, E.


    The archaeological works developed during the years 1996 in the site of Tafesa, 2005 in the 12 de Octubre Metro Station site and 2006 in the confluence of the Butarque Stream (Villaverde-Barrio de Butarque site) located south of the Madrid City (Spain), have provided new lithic assemblages. These assemblages have been stratigraphic ally contextualized in the Pleistocene deposits of the Lower Manzanares river valley within the so-called Manzanares Complex Terrace (TCMZ). This fluvial terrace constitutes an anomalous thickened (20-15m) deposit at {+-}22-16m above the present river thalweg mainly developed along the right (southern) valley margin. This fluvial level has been traditionally considered of middle Pleistocene age on the basis of the acheulian lithics and faunal assemblages typically located within its lower stratigraphic layers. Certainly, the Tafesa is a fluvial terrace site at {+-}22 m with acheulian industry and middle Pleistocene faunal remains at its lower sedimentary sequence. However, the upper sedimentary levels of this same terrace in the 12 de Octubre y Villaverde-Butarque sites throw lithic assemblages of the lower and upper Paleolithic belonging to upper Pleistocene, as suggested by the available set of TL and OSL dates for the zone. The analyses developed in this study indicate that the development of this thickened fluvial terrace started during the end of the middle Pleistocene, but also comprise the whole Oxygen Isotopic Stage OIS 5 during the upper Pleistocene. (Author) 95 refs.

  11. Confluence effects in rivers: Interactions of basin scale, network geometry, and disturbance regimes (United States)

    Benda, Lee; Andras, Kevin; Miller, Daniel; Bigelow, Paul


    We reviewed 14 studies documenting the effects of tributaries on river morphology at 167 confluences along 730 km of river spanning seven orders of magnitude in drainage area in western United States and Canada. In both humid and semiarid environments the probability of observing significant confluence-related changes in channel and valley morphology due to tributary influxes of sediment (e.g., changes in gradient, particle size, and terraces, etc.) increased with the size of the tributary relative to the main stem. Effects of confluences on river morphology are conditioned by basin shape and channel network patterns, and they include the nonlinear separation of geomorphically significant confluences in river networks. Other modifying factors include local network geometry and drainage density. Confluence-related landforms (i.e., fans, bars, terraces, etc.) are predicted to be dominated by older features in headwaters and younger features downstream, a pattern driven by the frequency and magnitude of floods and punctuated sediment supply that scale with watershed size.

  12. Large eddy simulation of natural ventilation for idealized terrace houses due to the effect of setback distance (United States)

    Tuan, L.; Abd Razak, A.; Zaki, S. A.; Mohammad, A. F.; Hassan, M. K.


    Similar to most tropical countries, Malaysia have low wind speed and airflow characteristics to provide an effective natural ventilation system for comfortable living especially in terrace houses. Even so, by designing them with suitable threshold height/width, H/W, ratio may help reduce heat sink, or even the accumulation of contaminants within the setback distance. Through this study, the downstream building of these terrace houses will be investigated due to the effects from an upstream building. With the use of Large-Eddy Simulation (LES) method, the formation of the vortex within the threshold H/W ratio will be clearly simulated and allow the observation of flow regimes developed by each model. With increasing threshold H/W ratios the models will exhibit some wake interference flow and skimming flow which will determine the negative or positive effect of ventilation from the upstream building towards the downstream building. The airflow characteristics of the downstream house will also be analysed and the most effective layout in providing a better air circulation may be determined. Improving the natural ventilation of such houses could significantly reduce these negative effects such as the accumulation of dust, smoke or bacteria. In turn, with the alarming rate of depletion in natural resources and its effects to the environment, this study can significantly reduce energy usage for ventilation and space cooling.

  13. Why most agricultural terraces in steep slopes in semiarid SE Spain remain well preserved since their abandonment 50 years go?

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    Cantón, F.


    Full Text Available A large part of the agricultural terraces in mountain environments are abandoned, like those from the Filabres range in Almería, SE Spain. While many of such terraces show signs of soil erosion (wall disruptions, surface crusts, pipes and gullies, others in steep slopes remain well preserved after 50 years since their abandonment and still seem to play an active role against soil erosion. In order to know both magnitude of soil erosion and controlling factors in different types of abandoned terraces, a rainfall simulation campaign with a portable sprinkler was carried out in 45 representative microsites. Runoff, derived-infiltration and sediment production were measured and their relationships to basic soil parameters (particle size distribution, pH, EC, organic matter content, aggregate stability, geomorphic position, and ground cover, were examined. Under the average applied rainfall intensity (48 mm/h, which represents a precipitation with a return period of 5 years in the area, narrow bench terraces from steep hillslopes, have larger infiltration values and deliver less sediments than large bank terraces in alluvial plains. The presence of stony pavement sieving crusts on narrow-bench terraces and also on un-terraced alluvial fans, play an essential armouring effect against soil erosion while favouring water infiltration. Considerations are made about the evolution of the different types of traditional terraces in the area under both past agricultural and present abandoned status, and also about possible uses under a sustainable land management policy.

    Una gran parte de las terrazas agrícolas en zonas de montaña están abandonadas, como las de la Sierra de los Filabres en Almería, SE de España. Si bien muchas de dichas terrazas muestran señales de erosión hídrica (destrucción de muros, encostramiento superficial, piping y cárcavas, otras en laderas con pendientes acusadas siguen bien conservadas tras 50 años de abandono y

  14. Occupants’ Utilization of Natural Ventilation: A Study of Selected Terrace House Designs in Hot-humid Climate

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    Ibiyeye AI


    Full Text Available With increased time spent indoors and demand for enhanced comfort levels, energy consumption in homes is rising mostly for cooling, particularly in hot-humid regions. Natural ventilation is seen as an alternative to mechanical cooling as it is totally independent on energy and has been reported to be of high potential. However, little information is available on the utilization of natural ventilation in individual living spaces in different house designs. Therefore, this paper aims to investigate occupants’ utilization of natural ventilation in living spaces under different terrace house designs in hot-humid climate and also the relationship between the openings and occupants’ satisfaction with natural ventilation. Five (5 different terrace house types in Putrajaya, Malaysia with different opening design characteristics were selected for the study. A total of 298 households from these house types were surveyed and results show that occupants mostly open their windows during the daytime to capture breeze from outside despite the fact that they owned air-conditioners. In terms of occupants’ level of satisfaction with indoor ventilation when utilizing natural ventilation, majority rated neither satisfied nor unsatisfied. Further regression analysis reveals that this level of satisfaction is significantly related to opening sizes that are in accordance with the law, duration of opening windows and AC ownership. Findings from this study will shed more light on behavioural pattern of occupants of residential buildings towards natural ventilation provisions and highlight the importance of conforming to the law governing them.

  15. Health-hazard evaluation report No. HETA 90-252-2167, Northland Terrace Nursing and Rehabilitation Center, Columbus, Ohio

    Energy Technology Data Exchange (ETDEWEB)

    Hanley, K.W.; Deitchman, S.


    In response to a request from management at the Northland Terrace Nursing and Rehabilitation Center (SIC-8051), Columbus, Ohio, a study was undertaken of headaches in workers in the laundry facility and upper respiratory infections associated with delivering Attends diapers. The study included employee interviews, environmental monitoring, and an assessment of the adequacy of the design and performance of the heating, ventilating, and air conditioning system. Northland Terrace was a nursing and rehabilitation center. Employees who work in the laundry facility reported that they experience headache while present in this area which was renovated in 1989. Carbon-dioxide (124389) concentrations exceeded 1000 parts per million. Biologically significant carbon-monoxide (630080) concentrations were not observed. Temperatures in the laundry rooms ranged from 86 to 92 degrees-F. Relative humidities ranged from 48 to 56%. A possible reaction to the dust or the fragrance associated with Attends diapers was not followed to completion as the nursing facility stopped using this product during the study. The authors conclude that there was an inadequate supply of outside air in the laundry and basement areas. The authors recommend measures to improve the ventilation system and reduce the potential for heat stress in the laundry.

  16. Provenance and sediment dynamics within river basins in Western Peru through detrital zircons U-Pb ages (United States)

    Camille, Litty; Pierre, Lanari; Marco, Burn; Fritz, Schlunegger


    U-Pb dating of detrital zircons from clastic sediments by LA-ICPMS has become a popular method in sedimentary correlation and provenance studies. Because of remarkable durability, detrital zircons may be reworked through multiple sedimentary cycles and provide an ideal material to study the sedimentary provenance in rivers and the erosional characteristics. The Western side of the Peruvian Andes has experienced multiple pluvial periods induced phases of erosion and the formation of subsequent cut-and-fill terrace sequences since the Pleistocene. The aim of the study is to estimate the source areas of the terrace and modern deposits to infer changes in sediment dynamics through time and correlate them with the climatic change and especially precipitation patterns. To this extent, we determined the provenance of 4 dated terrace deposits along with modern sediments from the same streams by matching detrital-zircon ages with crystallization ages of source rocks. Age populations of detrital zircons are derived using U-Pb LA-ICP-MS analysis of about 50 zircons. Results show changes in the sediment provenance through time. Nowadays, sediment source areas are mainly located on the uppermost reach of the rivers whereas during the Pleistocene, sediment source areas were both located in the headwaters and along the middle reach of the rivers. These differences in terms of provenance could correlate with a change in precipitation locations and rates. Indeed a scenario where the locus of precipitation occurrence shifted from the middle reaches including the Altiplano during the past, to the Altiplano only as observed today, along with higher precipitation rates during the periods of terraces formation, offers an explanation to explain the erosional patterns recorded by detrital zircons.

  17. Investigating Coseismic vs. Interseismic Uplift of Marine Terraces at the Southern Terminus of the Cascadia Subduction Zone: Cape Mendocino to Punta Gorda, Petrolia, CA (United States)

    Crawford, B.; Vermeer, J.; Hemphill-Haley, M. A.; Michalak, M.


    The Cascadia subduction zone of the Pacific Northwest terminates in the south at the Mendocino Triple Junction, a region of elevated seismic activity. Here, tectonically driven uplift is likely responsible for the formation of Holocene-aged marine terraces. In 1992, a M 7.1 thrust mainshock and two ~M 6.5 aftershocks occurred offshore of Cape Mendocino, resulting in 1.4 meters of uplift, measured from stranded intertidal species on uplifted wave-cut platforms. However, it is unknown whether these marine terraces formed due solely to large episodic coseismic uplift caused by moderately large to large magnitude earthquakes, orwhether interseismic deformation plays a role in their formation. Moreover, detailed mapping of these terraces has not been done since Merits (1996). For this study, we map a suite of four terraces and bedrock wave cut platforms between Cape Mendocino and Punta Gorda on the northern California coast near the town of Petrolia. By mapping both exposed and buried Holocene marine terraces we aim to discern the pattern of deformation causing their uplift, and determine whether uplift is related solely to episodic coseismic events, or both coseismic and interseismic deformation. Detailed mapping of the extent and elevation of both exposed and buried terraces is achieved by using real time kinematic (RTK) GPS surveying on base maps compiled using the 2009-2011 California Coastal Conservancy LIDAR. Preliminary results indicate formation predominantly from coseismic uplift in moderate magnitude subduction earthquakes. This work offers insight into understanding the upper plate crustal response to seismic events and interseismic periods in tectonically complex areas like the southern end of the Cascadia Subduction zone.

  18. The notion of climate-driven strath-terrace production assessed via dissimilar stream-process response to late Quaternary climate (United States)

    García, Antonio F.; Mahan, Shannon


    Previous research results from the Gabilan Mesa are combined with new optically stimulated luminescence (OSL) age estimates and sedimentological analyses with the aim of identifying factors that inhibit climate-driven strath-terrace production, and factors that make possible strath-terrace production independent of climate forcing. The factors are revealed by comparing the morphostratigraphy and OSL age estimates of terraces in the adjacent San Lorenzo Creek and Pancho Rico Creek drainage basins of the central California Coast Ranges. OSL age estimates on San Lorenzo Creek fill-terrace alluvium overlying bedrock at two paleofluvial levels range between 50.5 and 41.3 ka and between 33.4 and 18.2 ka. These OSL age estimates indicate that although the channel of Pancho Rico Creek was degrading at these times, San Lorenzo Creek aggradation was synchronous with previously documented regional, climatically driven aggradation that elsewhere in southern California led to strath production and alluvial deposition. The regional-scale climate forcing events had different effects on San Lorenzo and Pancho Rico Creeks because of the influences of drainage-basin lithology on bedload size and tectonic tilting direction on base-level fall. The Holocene history of channel denudation and strath production of Pancho Rico Creek is also different from that of San Lorenzo Creek, and different from that of many other streams in southern California. After Pancho Rico Creek captured the upper part of the drainage basin of San Lorenzo Creek sometime after 15.5 to 11.7 ka, Pancho Rico Creek has been producing unpaired, erosional strath terraces. The weak, clay rich, fine-grained sedimentary rock underlying Pancho Rico Valley is an ideal substrate in which to form straths. The meandering channel of Pancho Rico Creek produces straths, and weathering resistant, relatively hard bedload introduced by stream capture ensures their preservation as strath terraces.

  19. Effects of soil moisture retention on ice distribution and active layer thickness subject to seasonal ground temperature variations in a dry loess terrace in Adventdalen, Svalbard. (United States)

    Schuh, Carina; Frampton, Andrew; Christiansen, Hanne


    The active layer constitutes an important part of permafrost environments. Thermal and hydrological processes in the active layer determine local phenomena such as erosion and hydrological and ecosystem changes, and can have important implications for the global carbon-climate feedback. Permafrost degradation usually starts with a deepening of the active layer, followed by the formation of a talik and the subsequent thawing of permafrost. An increasing active layer thickness is therefore regarded as an indicator of permafrost degradation. The importance of hydrology for active layer processes is generally well acknowledged on a conceptual level, however the in general non-linear physical interdependencies between soil moisture, subsurface water and heat fluxes and active layer thaw progression are not fully understood. In this study, high resolution field data for the period 2000-2014 consisting of active layer and permafrost temperature, active layer soil moisture, and thaw depth progression from the UNISCALM research site in Adventdalen, Svalbard, is combined with a physically-based coupled cryotic and hydrogeological model to investigate active layer dynamics. The site is a loess-covered river terrace characterized by dry conditions with little to no summer infiltration and an unsaturated active layer. A range of soil moisture characteristic curves consistent with loess sediments is considered and their effects on ice and moisture redistribution, heat flux, energy storage through latent heat transfer, and active layer thickness is investigated and quantified based on hydro-climatic site conditions. Results show that soil moisture retention characteristics exhibit notable control on ice distribution and circulation within the active layer through cryosuction and are subject to seasonal variability and site-specific surface temperature variations. The retention characteristics also impact unfrozen water and ice content in the permafrost. Although these effects

  20. Pre-and post-Missoula flood geomorphology of the Pre-Holocene ancestral Columbia River Valley in the Portland forearc basin, Oregon and Washington, USA (United States)

    Peterson, Curt D.; Minor, Rick; Peterson, Gary L.; Gates, Edward B.


    Geomorphic landscape development in the pre-Holocene ancestral Columbia River Valley (1-5 km width) in the Portland forearc basin (~ 50 km length) is established from depositional sequences, which pre-date and post-date the glacial Lake Missoula floods. The sequences are observed from selected borehole logs (150 in number) and intact terrace soil profiles (56 in number) in backhoe trenches. Four sequences are widespread, including (1) a vertically aggraded Pleistocene alluvial plain, (2) a steep sided valley that is incised (125-150 m) into the Pleistocene gravel plain, (3) Missoula flood terraces (19-13 ka) abandoned on the sides of the ancestral valley, and (4) Holocene flooding surfaces (11-8 ka) buried at 70-30 m depth in the axial Columbia River Valley. Weathering rims and cementation are used for relative dating of incised Pleistocene gravel units. Soil development on the abandoned Missoula flood terraces is directly related to terrace deposit lithology, including thin Bw horizons in gravel, irregular podzols in sand, and multiple Bw horizons in thicker loess-capping layers. Radiocarbon dating of sand and mud alluvium in the submerged axial valley ties Holocene flooding surfaces to a local sea level curve and establishes Holocene sedimentation rates of 1.5 cm year- 1 during 11-9 ka and 0.3 cm year- 1 during 9-0 ka. The sequences of Pleistocene gravel aggradation, river valley incision, cataclysmic Missoula flooding, and Holocene submergence yield complex geomorphic landscapes in the ancestral lower Columbia River Valley.

  1. Chemical, mineralogical and physical characteristics of a material accumulated on the river margin from mud flowing from the collapse of the iron ore tailings dam in Bento Rodrigues, Minas Gerais, Brazil

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    Alexandre Christofaro Silva


    Full Text Available The rupture of an itabirito mining tailings dam at the headwaters of the Doce River Basin (Minas Gerais and Espírito Santo, Brazil caused the greatest environmental catastrophe of the planet Earth related to this activity. The tailings were deposited both in the bottom and on the riverside terrace of the rivers, causing silting and deep changes in the water quality and burial of the main agricultural areas of this basin. For these areas to return to pre-disaster levels, it is imperative that the material deposited on the river terraces be thoroughly characterized. The objective of this work was to characterize the material from the rupture of the Fundão dam, deposited on the river terrace of the Carmo River, a tributary of the Doce River. The material was collected at a depth of 0 to 30 cm from a tail layer about 3 meters thick deposited on the river terrace on the right bank of the Carmo River in the urban area of Barra Longa, Minas Gerais. The physical analyses included soil, particle and porosity density, chemical analyses were pH, sorption complex, organic matter, exchangeable Fe, Mn, Cu, Zn, Pb, Cd and Ni, total oxides, and mineralogical analyses were performed by X-ray diffractometer and Mössbauer spectrometry. The reject has high levels of sand and silt and a low clay content. The densities of soil and particles are high, and the porosity is low. The pH is alkaline, the levels of organic matter, plant nutrients and CEC are very low. The exchangeable heavy metals Zn, Cd, Cu, Pb and Ni are very low, and the exchangeable Mn contents of the tailings are high. The predominant total oxides of the tailings are SiO2 and Fe2O3. The most abundant minerals of the tailings are quartz and hematite. The physical, chemical, and mineralogical attributes of mine tailings restrict the restoration of native vegetation or the agricultural use of the river terraces on which it was deposited.

  2. LiDAR derived high resolution topography: the next challenge for the analysis of terraces stability and vineyard soil erosion

    Directory of Open Access Journals (Sweden)

    Federico Preti


    Full Text Available The soil erosion in the vineyards is a critical issue that could affect their productivity, but also, when the cultivation is organized in terraces, increase the risk due to derived slope failure processes. If terraces are not correctly designed or maintained, a progressively increasing of gully erosion affects the structure of the walls. The results of this process is the increasing of connectivity and runoff. In order to overcome such issues it is really important to recognize in detail all the surface drainage paths, thus providing a basis upon which develop a suitable drainage system or provide structural measures for the soil erosion risk mitigation. In the last few years, the airborne LiDAR technology led to a dramatic increase in terrain information. Airborne LiDAR and Terrestrial Laser Scanner derived high-resolution Digital Terrain Models (DTMs have opened avenues for hydrologic and geomorphologic studies (Tarolli et al., 2009. In general, all the main surface process signatures are correctly recognized using a DTM with cell sizes of 1 m. However sub-meter grid sizes may be more suitable in those situations where the analysis of micro topography related to micro changes is critical for slope failures risk assessment or for the design of detailed drainage flow paths. The Terrestrial Laser Scanner (TLS has been proven to be an useful tool for such detailed field survey. In this work, we test the effectiveness of high resolution topography derived by airborne LiDAR and TLS for the recognition of areas subject to soil erosion risk in a typical terraced vineyard landscape of “Chianti Classico” (Tuscany, Italy. The algorithm proposed by Tarolli et al. (2013, for the automatic recognition of anthropic feature induced flow direction changes, has been tested. The results underline the effectiveness of LiDAR and TLS data in the analysis of soil erosion signatures in vineyards, and indicate the high resolution topography as a useful tool to

  3. Temporal dynamics of plant succession in abandoned field in Mediterranean mountain areas: farming terraces and sloping fields (Iberian System, Spain) (United States)

    Nadal-Romero, Estela; Errea, Paz; Lasanta, Teodoro


    Cropland abandonment is an important problem in mountain areas worldwide. This process represents the change from an agricultural management to an abandoned land in which a complex plant succession process occurs, with important hydromorphological effects, and consequences in water resources availability and soil erosion. Literature indicates that plant succession depends on multiple natural factors (soil properties, topography, climate, lithology, and distance to natural covers…) and anthropogenic factors (age of abandonment, management of each field during the cultivation period and after the abandonment…). Despite the advances, much is unknown about the vegetation succession, due to the complexity of ecological and social conditions in which land abandonment occurs. Recently, it is shown that only local factors can explain the heterogeneity of the process (Burel and Baudry, 2002; Jouba and Alados, 2012). In this work, we analyze the diversity of vegetation cover in abandonment fields in Cameros Viejo (Iberian System, Spain), related to the different field patterns (terraces and sloping fields) and the age of abandonment. Agricultural lands were delimited using aerial photographs from 1956 and 1978. The current land cover was obtained from SIOSE (Information System of Land Occupation in Spain). According to our cartography, cultivated land occupied as much as 15,491 ha (39% of the area), remaining abandoned 14,505 ha by 1978. Farming terraces occupied 55.9% of the abandoned area, and 44.1% as sloping fields. On the other hand, our cartography highlights the complexity of current land cover of abandoned fields in a landscape matrix of scrubland. Our results suggest that ecological succession is faster in farming terraces than in sloping fields, mostly until scrubland phase is attained. They also suggest that current land cover is better explained by the physical conditions of each field than by the abandonment age. Acknowledgement This research was supported

  4. Monsoonal vs. glacial control on erosion and sediment storage in the Himalayan rain shadow, Zanskar River, northwest India (United States)

    Jonell, Tara; Clift, Peter; Carter, Andrew; Böning, Philipp; Wittmann, Hella


    Summer monsoon precipitation strongly controls erosion and sediment storage in the frontal Himalaya but the relationship between monsoonal variability and erosion is less well-constrained beyond the High Himalayan topographic divide in the rain shadow. Here we establish a Quaternary erosional history for a rain shadow tributary of the upper Indus River system, the Zanskar River, by applying several sediment provenance techniques to modern and dated terrace river sediments. We evaluate if there are temporal links between sediment storage and moisture supply to the rain shadow and if regions like the Zanskar River basin play a significant role in controlling total sediment flux to the Indus River. We compile bulk sediment petrography and Sr and Nd isotope geochemistry, detrital U-Pb zircon and apatite fission track dating with in-situ 10Be cosmogenic radionuclide techniques to identify patterns of erosion and sediment production across Zanskar. Bulk petrography, Sr and Nd isotope geochemistry, and U-Pb detrital zircon spectra of modern and older terrace sediments indicate high rates of erosion along the Greater Himalaya in the Zanskar River basin. We find that the wettest and most glaciated subcatchment dominates the bulk sediment provenance signal, with only moderate input from other tributaries, and that other basin parameters cannot explain our observations. Catchment-averaged in-situ 10Be cosmogenic nuclide concentrations of modern sediments indicate erosion rates up to ˜1.2 mm y-1 but show strong dilution attributed to glacial sediment recycling into the modern river, suggesting rates nearer 0.4-0.6 mm•y-1. These rates are consistent with longer-term rates of incision (0.3-0.7 mm•y-1) calculated from detrital apatite fission track ages, and incision rates inferred from Late Glacial and Holocene terraces near the Zanskar-Indus confluence. Our findings suggest that sediment production in glaciated Himalayan rain shadow environments like Zanskar is largely

  5. Yangzhou’s Famous Twenty-fourth Bridge

    Institute of Scientific and Technical Information of China (English)


    “LOOMING green moun-tains and runningstreams;grass does notwither and fall,though the autumnhas come to an end in the south.The bright moon arises overTwenty-fourth Bridge.Where doyou teach pure-jade Yangzhouwomen to play music on bambooflutes?”This poem by Du Mu(803-c.852),a famous poet of thelate Tang Dynasty,is well remem-bered today It made Yangzhou’sTwenty-fourth Bridge Known to la-ter generations.Of many ancientpoems about Twenty-fourth Bridge

  6. Comparing the Planform Morphologies of a Freely Meandering Channel and the Bedrock- Controlled South River, VA. (United States)

    Narinesingh, P.; Pizzuto, J.


    The planforms of the lithologically controlled South River, VA, and the freely meandering Teklanika River, AK were investigated using two statistical methods as well as fractal and spectral analyses. The lithologic controls along the South River include riverbanks consisting of pre-Holocene terraces and alluvial fans, and highly resistant bedrock that frequently crops out both in the bed and along the banks. A statistical analysis of bends composed of single arcs shows that the average radius of curvature is six times greater and the average bend length is 25 percent smaller for the South River relative to the meandering river, indicating that lithologically controlled bends are less curved and shorter than freely-formed meander bends. Fractal analysis reveals that the meandering river displays a smaller range in length scales than the South River, which exhibits a wider range in length scales that reflect a wider distribution of bend sizes. The method of Lancaster and Bras, (2002), which identifies bends of different complexity, indicates that the meandering river displays bends composed of single arcs, complex arcs and multiple complex arcs. Unlike the freely meandering Teklanika River, the lithologically controlled South River does not display bends composed of multiple complex arcs, though bends composed of single and complex arcs are common. Spectral analysis reveals that the meandering river's pattern is composed of a relatively narrow range of dominant wavelengths with the most prominent wavelength being the longest, while the lithologically controlled river displays dominant wavelengths over a relatively wide range and the most prominent wavelength is not the longest. This analysis demonstrates that lithological controls increase the range of bend lengths, increase radii of curvature, simplify bend shapes, and increase the distribution of wavelengths of sinuous rivers.

  7. Geochemistry of Late Cretaceous (60- 67 Ma) igneous activities in the Hebrides Terrace seamount (guyot) area, Scotland

    Institute of Scientific and Technical Information of China (English)

    M. El-Tokhi; M. Omran; A. El-Muslem


    Tholeiitic basalts in various stages of alteration were dredged from Late Cretaceous volcanic rocks (60 -67 Ma) in the Hebrides Terrace seamount area in the Atlantic Ocean. These rocks are extrusive olivine basalts, including high- and low-Al basalts. High-Al basalts are depleted in MgO, CaO, Cr,Sc, V, Sr, Zr and enriched in TiO2, Na2 O, Nb, Rb as compared with low-Al basalts. Petrography and bulk-rock composition (major, trace and rare-earth elements) data defined clear tholeiitic suites displaying possible liquid lines of descent related to different degrees of crystal fractionation and partial melting.Isotopic dating of dredged samples gave the guyot an age of 60 - 67 Ma, in support of the assumption that it was formed during the Late Cretaceous.

  8. Terrace-width distributions of touching steps: Modification of the fermion analogy with implications for measuring step-step interactions (United States)

    Sathiyanarayanan, Rajesh; Hamouda, Ajmi Bh.; Einstein, T. L.


    Using Monte Carlo simulations, we compute the terrace-width distributions (TWDs) of surfaces in which steps can touch each other, forming multiple-atomic height steps, but cannot cross (no overhangs), and so inconsistent with the standard mapping to spinless fermions. Our results show that the generalized Wigner distribution with minor modifications at small step separations, gives a very good fit for TWDs of touching steps. The interaction strength derived from the fit parameter (ϱ) indicates an effective attraction between steps. The strength of this effective attraction decreases for larger mean-step separations and decreasing step-touching energies; describable via finite-size scaling. Hence, accurate extraction of the true repulsion strength requires multiple vicinalities.

  9. Fault slip-rates derived from modeling of on-shore marine terraces in the western Corinth Gulf (United States)

    Palyvos, Nikos; De Martini, Paolo Marco; Mancini, Marco; Pantosti, Daniela


    Data available for estimating fault slip-rates from accurate modeling of uplifted on-shore marine terraces although limited are all derivatives of the research activity performed from 2004 to 2007 within the 3HAZ-Corinth project. We concentrated our efforts in the Aravonitsa area where we had a nicely preserved staircase of marine terraces. In particular, we recognized and mapped in detail all the marine terraces by qualitative DEM analysis, airphoto interpretation and field survey and we adopted a forward modeling procedure to fit the data. The modeling approach we used in this work does not take into account any effect related to sedimentation, compaction and erosion nor any interseismic adjustment and thus, being purely based on coseismic deformation, the obtained results should be considered as maxima. In the study area we were able to recognize several surfaces related to sea-level still stands. Their areal distribution and elevation are strongly influenced by past intense erosion on the underlying weakly consolidated sediments, and by the activity of secondary faults at the footwall of the Neos Erineos Fault, being part of the Lambiri - Neos Erineos - Aigion Fault zone (LANEfz). The Neos Erineos Fault has been studied and investigated in details and it appears as one of the main N-dipping normal faults bounding the southern shore of the Corinth Gulf and taking on part of the observed N-S striking extension. U/Th-series age dates and nannoplankton analyses, performed on selected samples collected at different heights on the studied surfaces, allowed us to to reconstruct an almost complete and chronologically well constrained transect of uplifted marine terraces belonging to the Late Quaternary (as old as 350 ka). A tentative correlation with marine isotopic stages (MIS) and specifically with main highstands from the Late Quaternary eustatic sea-level curve was attempted in order to calculate footwall uplift rate for the Neos Erineos Fault. The calculated

  10. Impact of land-use change on soil degradation by establishment of terraces with subtropical orchards in sloping areas (Granada, SE Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Pleguezuelo, C. R.; Duran Zuzo, V. H.; Martin Peinado, F. J.; Franco Tarifa, D.


    In the coast of Granada, an intensive irrigated agriculture based on subtropical crops has been established. These trees have been planted in highly sloped areas, by the construction of terraces. In this fragile Mediterranean agroecosystem, the removal of native spontaneous vegetation cover and substitution by orchards, increase the susceptibility to soil degradation and eventually brings up the destruction of these structures by rainfall events. To study this net change, we monitored the soil loss and runoff over a two-year period in the taluses of terraces with a mature mango (Mangifera indica L.) orchard. The studied treatments were bare soil (BS) and spontaneous vegetation (NSV), each twice replicated. The erosion plots were 4 m x 4 m in area and were located in the taluses of orchard in the taluses of orchard terraces (65 degree centigrade slope). The average annual soil loss by erosion for BS and NSV was 2.5 and 0.3 Mg ha{sup -}1 yr{sup -}1, and for runoff 34.1 and 6.8 mm yr{sup -}1, respectively. Therefore, soil erosion and runoff from BS plot were 8- and 5-times higher than in NSV, showing the importance of plant covers in the taluses of terraces in reducing this impact. Thus, the removal of plant cover from the taluses under these conditions, represent a high risk of slump and collapse, causing serious environmental and economic problems for farmers of subtropical crops. (Author) 11 refs.

  11. Locking ssDNA in a Graphene-Terraces Nanopore and Steering Its Step-by-Step Transportation via Electric Trigger

    CERN Document Server

    Lv, Wenping; Xu, Dongsheng; Wu, Renan


    This study demonstrates that the nanopore terraces constructed on a multilayer graphene sheet could be employed to con-trol the conformation and transportation of an ssDNA for nanopore sequencing. As adsorbed on a terraced graphene na-nopore, the ssDNA has no in-plane swing nearby the nanopore, and can be locked on graphene terraces in a stretched con-formation. Under biasing, the accumulated ions near the nanopore promote the translocation of the locked ssDNA, and also disturb the balance between the driven force and resistance force acted on the nucleotide in pore. A critical force is found to be necessary in trigging the kickoff of the ssDNA translocation, implying an inherent field effect of the terraced graphene nanopore. By changing the intensities of electric field as trigger signal, the stop and go of an ssDNA in the nanopore are manipulated at single nucleobase level. The velocity of ssDNA in the nanopore can also be regulated by the frequency of the electro-stimulations. As a result, a new scheme of...

  12. Powder River: data for cross-channel profiles at 22 sites in southeastern Montana from 1975 through 2012 (United States)

    Moody, John A.; Meade, Robert H.


    Powder River rises in the Bighorn Mountains of Wyoming and flows northward through a semi-arid landscape in Wyoming and Montana to the Yellowstone River. The river drains an area of 34,700 km2 and has an average discharge of about 500 million m3 y-1 or 16 m3 s-1. This view of the river looking northward, and hence downstream, was taken in October 2012 (see study reach map), about 20 km north of the Wyoming-Montana state line, about 4 km downstream from an operating gaging station at Moorhead, Montana (USGS station number 06324500), and about 80 river km upstream from a discontinued gaging station at Broadus, Montana (USGS station number 06324710). The river is emerging from a narrowly-confined reach, and the valley widens northward, bordered by hills of the coal-bearing Fort Union Formation. The river in this photo is at about bed-full flow (12 m3 s-1, Moody and others, 1999), and several riffles with disturbed water can be seen downstream between smooth glassy reaches of the river. A narrow band (~2-4 m wide) of reddish sedge (Scirpus spp.) grows just above the bed-full level along the edge of water with a wider band of mixed grasses (Agropyron repens, A. pauciflorum, Bromus inermis, Elymus canadenis, Spartina pectinata, and S. cynosoroids), willow (Salix exigua), tamarisk (Tamirix ramosissima) and small cottonwood seedlings and trees (Populus sargentii) on the flood plain. Three terrace levels have been identified along the river (Leopold and Miller, 1954; Moody and Meade, 2008). The first is the Lightning terrace with small cottonwood trees (seen here without leaves) adjacent to the floodplain in the right-center of the photo. The second is the Moorcroft terrace seen best forming the left bank and extending as a flat surface to the left (west) with a few large cottonwood trees still retaining their green leaves. The third is the colluvial Kaycee terrace that grades slowly upwards and meets the hills of the Fort Union Formation. It can be seen on the right side

  13. Twenty-Seventh Symposium (International) on Combustion. Volume 1 (United States)


    pollutant emissions on human driving the development of highly efficient low- health range from respiratory diseases (e.g., child- emission combustion...Systems (N. 101. Stein, S. E., Walker, J. A., Suryan, M. M., and Fahr , Peters and B. Rogg, eds.), Lecture Notes in Physics, A., in Twenty-Third Symposium...M. M., and Fahr , A., and Kawano, H., Int. j. Chem. Kinet. 21:643-666 in Twenty-Third Symposium (International) on Com- (1989). bustion, The

  14. Recognition of Pleistocene marine terraces in the southwest of Portugal (Iberian Peninsula: evidences of regional Quaternary uplift

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    Paula M. Figueiredo


    Full Text Available Southwest mainland Portugal is located close to the Eurasia-Nubia plate boundary and is characterized by moderate seismicity, although strong events have occurred as in 1755 (Mw≥8, 1969, (Mw 7.9, and more recently in 2007 (Mw 5.9 and 2009 (Mw 5.5, all located in the offshore. No historical earthquakes with onshore rupture are known for this region. At the coastline, high sea cliffs, incised drainages, emergent marine abrasion platforms and paleo sea cliffs indicate that this region is undergoing uplift, although no morphological features were found that could be unequivocally associated with the 1755 mega earthquake. To better understand the recent tectonic activity in this sector of Iberia, it is necessary not only to analyze active structures on land, but also to search for evidence for deformation that may relate to inferred offshore active structures. We thus conducted a study of marine terraces along the coastline to identify regional vertical crustal motions. Several poorly preserved surfaces with thin sedimentary deposits, comprising old beach sediments, were recognized at elevations starting at 2 m elevation and rising inland up to a regional abrasion platform situated at about 120 m a.s.l.. We identified distinct paleo sea level references at several locations at consistent elevations. This terrace sequence is likely Late Pleistocene in age, with individual platforms correlative to MIS 5 high stands and is coherent with a long-term slow uplift of the littoral zone for the southwest of Portugal. Although dating of discrete platforms is an ongoing and difficult task, preliminary correlations of paleo-shoreline elevations suggest that the uplift rate is in the range of 0.1-0.2 mm/yr.

  15. Evaluation of agricultural best-management practices in the Conestoga River headwaters, Pennsylvania; hydrology of a small carbonate site near Ephrata, Pennsylvania, prior to implementation of nutrient management (United States)

    Koerkle, E.H.; Hall, D.W.; Risser, D.W.; Lietman, P.L.; Chichester, D.C.


    The U.S. Geological Survey, in cooperation with the U.S. Department of Agriculture and Pennsylvania Department of Environmental Protection, investigated the effects of agricultural best-management practices on water quality in the Conestoga River headwaters watershed. This report describes environmental factors and the surface-water and ground-water quality of one 47.5-acre field site, Field-Site 2, from October 1984 through September 1986, prior to implementation of nutrient management. The site is partially terraced agricultural cropland underlain by carbonate rock. Twenty-seven acres are terraced, pipe-drained, and are under no-till cultivation. The remaining acreage is under minimum-till cultivation. Corn is the primary crop. The average annual rate of fertilization at the site was 480 pounds per acre of nitrogen and 110 pounds per acre of phosphorus. An unconfined limestone and dolomitic aquifer underlies the site, Depth to bedrock ranges from 5 to 30 feet below land surface. Estimated specific yields range from 0.05 to 0.10, specific capacities of wells range from less than 1 to about 20 gallons per minute per foot of drawdown, and estimates of transmissivities range from 10 to 10,000 square feet per day. Average ground-water recharge was estimated to be about 23 inches per year. The specific capacity and transmissivity data indicate that two aquifer regimes are present at the site. Wells drilled into dolomites in the eastern part of the site have larger specific capacities (averaging 20 gallons per minute per foot of drawdown) relative to specific capacities (averaging less than 1 gallon per minute per foot of drawdown) of wells drilled into limestones in the western part of the site. Median concentrations of soil-soluble nitrate and soluble phosphorus in the top 4 feet of silt- or silty-clay-loam soil ranged from 177 to 329 and 8.5 to 35 pounds per acre, respectively. Measured runoff from the pipe-drained terraces ranged from 10 to 48,000 cubic feet and was

  16. Landscape evolution due to river incision in active mountains (United States)

    Lavé, L.; Attal, A.


    It is commonly accepted that fluvial network incision control the local base level for hillslopes and therefore controls the rate of landscape denudation, and thus the way the landscape will respond to tectonic or climatic forcings. For that reason, many studies have focused for the last ten years in quantifying fluvial incision rates and the mechanisms of fluvial incision into bedrock. In many morphotectonic settings the shear stress model has been widely used and provided satisfactory first order description of the river incision in active mountains. Across the Siwaliks range in front of the Himalaya, the shear stress model (that also includes bedload mean pebble size and explicit channel width variations), provides a good proxy to estimate incision and uplift rate, that can be measured independently from fluvial terraces studies. By transposition and after calibration to more resistant crystalline lithologies, this model helped to define the incision rate profiles across the whole Himalayan ranges. These profiles were found coherent with current seismotectonic model, sediment budget, fluvial terrace studies and geochronology results. More importantly, the incision model was found to provide good results in two other active regions: across the Nanga Parbat massif in Pakistan, and in the San Gabriel Ranges in California, with only minor required changes of the erodibility coefficient despite very different hydroclimatic setting. However, this semi-empirical model is not mechanically satisfying: in many settings, river bedload fluxes exert an important control on incision rates, by limiting bedrock exposure or by providing an efficient tool for river mechanical abrasion. A reappraisal of the former examples as thus conducted in order to test different models including the role of sediment fluxes. General results and models will be first discussed in light of their physical consistency with field and experimental data on pebble and bedrock abrasion, and second in

  17. Rediscovery of the 8th Natural Wonder of the World: The Pink and White Terraces' survival of the 1886 Tarawera Rift eruption (United States)

    de Ronde, C. E.; Fornari, D. J.; Ferrini, V.; Caratori Tontini, F.; Walker, S. L.; Scott, B. J.; Leybourne, M. I.; Pittari, A.; Keam, R. F.; Lupton, J. E.; Mazot, A.; Kukulya, A.; Littlefield, R.; Immenga, D.; Stagpoole, V.; Timm, C.; Berthelsen, T. J.


    On June 10, 1886, Mt. Tarawera in the rhyolitic Okataina Volcanic Centre of the central North Island, New Zealand, erupted in spectacular fashion. Basaltic eruptions at Tarawera produced tall eruption columns, while hydrothermal and phreatomagmatic eruptions at Rotomahana excavated the pre-1886 Lake Rotomahana site, which later filled to form a new lake up to 125 m deep and ~5 x larger than its predecessor. The Pink and White Terraces, which were the world's largest silica aprons and buttresses, had formed as a result of discharging thermal waters and deposition of silica on the margins of the pre-1886 lake, and were believed destroyed during the 1886 eruption. The post-eruption landscape was scarred by eruption craters with the largest marking the foci of the phreatomagmatic eruption, which blanketed the area with 10s of m of mud. A combined ~250 line km survey of Lake Rotomahana was conducted using two REMUS 100 AUVs simultaneously mapping with multibeam and sidescan sonar. Also fitted were a magnetometer, minature plume recorders (LSS, Eh, temperature, depth) and pH sensors. Surface vessels conducted magnetic surveys (110 line km), CO2 flux measurements (420 sites), deployed a CTD and Niksin bottles for water properties and sampling (14 stations), and a camera over sites (12) of known venting and/or where the sidescan showed evidence for the terraces. New bathymetric data clearly shows the en-echelon rift of 1886 in the center of the lake and identifies some pre-1886 shoreline. When combined with sidescan sonar images, several of the basal layers of the Pink Terraces were found very near their original, pre-eruption locations. Underwater photographs reveal buttresses of several tiers. Magnetic data show a pronounced positive anomaly in the southern part of the lake, associated with older lavas, and a distinct negative anomaly associated with the Pink Terraces, marking the boundaries of the pre-1886 geothermal field. Bubble plumes recorded during the magnetic

  18. A view of late glacial runoff from the lower Mississippi River valley

    Energy Technology Data Exchange (ETDEWEB)

    Saucier, R.T. (Army Engineer Waterways Experiment, Vicksburg, MS (United States))


    Thousands of cubic kilometers of massive coarse-grained Late Wisconsin glacial outwash underline the Mississippi alluvial plain, however, the deposits are exposed at the surface primarily only in the Eastern Lowlands. There the valley train deposits form a series of low, flat terraces characterized by a distinctive pattern of relict braided channels. The terrace levels reflect episodes of meltwater release and possibly catastrophic flood events, but precise correlations to Midwest events have not been possible. The detailed chronology of late glacial runoff in the valley is not resolved, but certain key events have been temporally defined. Diversion of the Mississippi River from the Western to the eastern Lowlands began about 16,000 B.P. The high and intermediate terrace levels formed between 14,500 and 11,000 B.P. during the peak of late glacial runoff: the intermediate level was abandoned and had wide-spread human habitation by 10,000 B.P. Following a lull in runoff after 11,000 B.P., a diversion of the river through Thebes Gap and the formation of the well-defined Charleston Fan in southeast Missouri was possibly triggered by a sudden and brief meltwater release event. Sedimentological and archeological evidence suggest this occurred between 10,500 and 10,000 B.P. By about 9,800 B.P., the river had ceased carrying meltwater and was flowing in a meandering regime. Because most outwash in the valley is buried, opportunities for direct investigation will always be limited. However, indirect study of outwash via impacts on sedimentation in tributary valleys, banding in loess deposits, and distribution of ice-rafted erratics should yield new chronostratigraphic evidence.

  19. Characterization of geomorphic units in the alluvial valleys and channels of Gulf Coastal Plain rivers in Texas, with examples from the Brazos, Sabine, and Trinity Rivers, 2010 (United States)

    Coffman, David K.; Malstaff, Greg; Heitmuller, Franklin T.


    The U.S. Geological Survey, in cooperation with the Texas Water Development Board, described and characterized examples of geomorphic units within the channels and alluvial valleys of Texas Gulf Coastal Plain rivers using a geomorphic unit classification scale that differentiates geomorphic units on the basis of their location either outside or inside the river channel. The geomorphic properties of a river system determine the distribution and type of potential habitat both within and adjacent to the channel. This report characterizes the geomorphic units contained in the river channels and alluvial valleys of Texas Gulf Coastal Plain rivers in the context of the River Styles framework. This report is intended to help Texas Instream Flow Program practitioners, river managers, ecologists and biologists, and others interested in the geomorphology and the physical processes of the rivers of the Texas Gulf Coastal Plain (1) gain insights into how geomorphic units develop and adjust spatially and temporally, and (2) be able to recognize common geomorphic units from the examples cataloged in this report. Recent aerial imagery (high-resolution digital orthoimagery) collected in 2008 and 2009 were inspected by using geographic information system software to identify representative examples of the types of geomorphic units that occurred in the study area. Geomorphic units outside the channels of Texas Gulf Coastal Plain rivers are called \\"valley geomorphic units\\" in this report. Valley geomorphic units for the Texas Gulf Coastal Plain rivers described in this report are terraces, flood plains, crevasses and crevasse splays, flood-plain depressions, tie channels, tributaries, paleochannels, anabranches, distributaries, natural levees, neck cutoffs, oxbow lakes, and constructed channels. Channel geomorphic units occur in the river channel and are subject to frequent stresses associated with flowing water and sediment transport; they adjust (change) relatively quickly in

  20. Socioeconomic dimensions of changes in the agricultural landscape of the Mediterranean basin: a case study of the abandonment of cultivation terraces on Nisyros Island, Greece. (United States)

    Petanidou, Theodora; Kizos, Thanasis; Soulakellis, Nikolaos


    Agricultural landscapes illustrate the impact of human actions on physical settings, and differential human pressures cause these landscapes to change with time. Our study explored changes in the terraced landscapes of Nisyros Island, Greece, focusing on the socioeconomic aspects during two time periods using field data, cadastral research, local documents, and published literature, as well as surveys of the islanders. Population increases during the late 19th to early 20th centuries marked a significant escalation of terrace and dry stone wall construction, which facilitated cultivation on 58.4% of the island. By the mid-20th century, the economic collapse of agricultural activities and consequent emigration caused the abandonment of cultivated land and traditional management practices, dramatically reducing farm and field numbers. Terrace abandonment continued in recent decades, with increased livestock grazing becoming the main land management tool; as a result, both farm and pasture sizes increased. Neglect and changing land use has led to deterioration and destruction of many terraces on the island. We discuss the socioeconomic and political backgrounds responsible for the land-use change before World War II (annexation of Nisyros Island by the Ottoman Empire, Italy, and Greece; overseas migration opportunities; and world transportation changes) and after the war (social changes in peasant societies; worldwide changes in agricultural production practices). The adverse landscape changes documented for Nisyros Island appear to be inevitable for modern Mediterranean rural societies, including those on other islands in this region. The island's unique terraced landscapes may qualify Nisyros to become an archive or repository of old agricultural management techniques to be used by future generations and a living resource for sustainable management.

  1. Socioeconomic Dimensions of Changes in the Agricultural Landscape of the Mediterranean Basin: A Case Study of the Abandonment of Cultivation Terraces on Nisyros Island, Greece (United States)

    Petanidou, Theodora; Kizos, Thanasis; Soulakellis, Nikolaos


    Agricultural landscapes illustrate the impact of human actions on physical settings, and differential human pressures cause these landscapes to change with time. Our study explored changes in the terraced landscapes of Nisyros Island, Greece, focusing on the socioeconomic aspects during two time periods using field data, cadastral research, local documents, and published literature, as well as surveys of the islanders. Population increases during the late 19th to early 20th centuries marked a significant escalation of terrace and dry stone wall construction, which facilitated cultivation on 58.4% of the island. By the mid-20th century, the economic collapse of agricultural activities and consequent emigration caused the abandonment of cultivated land and traditional management practices, dramatically reducing farm and field numbers. Terrace abandonment continued in recent decades, with increased livestock grazing becoming the main land management tool; as a result, both farm and pasture sizes increased. Neglect and changing land use has led to deterioration and destruction of many terraces on the island. We discuss the socioeconomic and political backgrounds responsible for the land-use change before World War II (annexation of Nisyros Island by the Ottoman Empire, Italy, and Greece; overseas migration opportunities; and world transportation changes) and after the war (social changes in peasant societies; worldwide changes in agricultural production practices). The adverse landscape changes documented for Nisyros Island appear to be inevitable for modern Mediterranean rural societies, including those on other islands in this region. The island’s unique terraced landscapes may qualify Nisyros to become an archive or repository of old agricultural management techniques to be used by future generations and a living resource for sustainable management.

  2. Trophic strategies in carnivorous fishes: their significance in energy transfer in the deep-sea benthic ecosystem (Meriadzek Terrace — Bay of Biscay) (United States)

    Mahaut, Marie-Laure; Geistdoerfer, Patrick; Sibuet, Myriam

    Trophic relationships between fish species have been analyzed as a contribution to the construction of an energy transfer model between various groups in the benthic ecosystem of Meriadzek Terrace, located at 170 miles off the west French coast at a depth of 2100m. Attention was given to the carnivorous megafaunal compartment. The importance of the carnivore megafaunal biomass and its part in energy transfer is still unresolved. On the Meriadzek Terrace, numerous Chondrichthyes (sharks and chimeroids) were frequently observed from the manned submersible Cyana or by baited camera; their biomass appears to be exceptionally large. Results of a photographic survey conducted using the unmanned free vehicle Epaulard have given estimates of 22 per 10 4m 2 of teleost fishes (belonging to 8 different families and one suborder) but included no Chondrichthyes (except one specimen of Rajidae). From baited camera observations, however, we conclude that carcasses falling to the bottom on the Terrace are exploited only by selacians as the bait was never seen to be eaten by macrourids, morids or synaphobranchids although they always attended the baits before the arrival of large scavengers. Trophic specialization strategies occur in this deep-sea ecosystem and our further studies on the energy transfer model for the Meriadzek Terrace will differentiate between strategies exploiting two sources of organic input to the bottom environment: organic particles and large carcasses. In one case, carbon transfer is via the whole benthic food web in which each link is specified by size and trophic behaviour. This pathway ends in the carnivorous megafaunal compartment, which includes benthic fishes, consumers of the local epibenthic and sometimes inbenthic, macro- and megafauna. The second pathway originates with carcass falls, and carbon transfer is direct to the benthopelagic scavengers observed frequently at the Meriadzek Terrace.

  3. 河流对0.8 Ma B.P.环境突变事件的地貌响应研究%Geomorphic Response of the River to the Environmental Change Event at 0.8 Ma B.P.

    Institute of Scientific and Technical Information of China (English)

    胡春生; 周迎秋


    以兰州盆地0.8 Ma B.P.阶地为例证,运用古地磁测年方法,通过收集相关文献,分析讨论了0.8 Ma B.P.阶地与0.8 Ma B.P.环境突变事件的联系。结果表明:①0.8 Ma B.P.环境突变事件主要表现在气候转型、构造运动等方面,具有群发性和全球性特点;②兰州盆地以及其他区域0.8 Ma B.P.阶地存在的证据,表明河流在0.8 Ma B.P.前后普遍发生过一次下切事件;③0.8 Ma B.P.阶地是河流对0.8 Ma B.P.环境突变事件的地貌响应,构造运动为提供了下切驱动力,而气候变化则控制了下切时间。%Based on a large number of research data on the environmental change events at 0.8 Ma B.P. and the 0.8 Ma B.P. terraces, this paper, which takes the Lanzhou Basin as an example, discusses the internal relation-ship between the 0.8 Ma B.P. terraces and the events of environmental change at 0.8 Ma B.P.. In the Lanzhou Basin, there are two river terraces, namely the Zaoshugou terrace and the Wuyishan terrace, which are selected respectively as the study terraces. For the Zaoshugou terrace, the altitude of gravel stratum is 80 m higher than the river level. The top of the gravel stratum is covered by at least 64 m eolian loess, and the paleosol S8 is at the bottom of the eolian loess. While for the Wuyishan terrace, the altitude of gravel stratum is 140 m higher than the river level. The top of the gravel stratum is overlain by about 100 m eolian loess, and the paleosol S8 is also at the bottom of the eolian loess. Through the paleomagnetic dating and loess-paleosol sequence match-ing, it is discovered that these two terraces have the same age, and both were developed at about 0.865 Ma B. P.. According to the analysis of sedimentary characteristics and the correlative literature of tectonic movement, these two terraces show significant attribute of the tectonic movement genesis. At the same time, they also have similar lithology that there is a paleosol developed on

  4. River Incision, Sediment Storage, and Sediment Residence Times at the Western Tibetan Plateau Margin (United States)

    Bloethe, J. H.; Munack, H.; Fülling, A.; Resentini, A.; Garzanti, E.; Kubik, P.; Korup, O.


    Intermediate sediment storage protects underlying bedrock from incision, buffers sediment delivery from adjacent hillslopes and provides the source for potentially catastrophic sediment release. Along the western Tibetan plateau margin, broad alluviated valleys host large valley fills. Besides sediment storage in major valleys, deeply incised bedrock gorges also have the potential to store sediment for > 104 yrs, even though they are typically portrayed as conveyor belts for incoming sediment. Here we report on cyclic aggradation and re-incision of fluvial terraces near the Tibetan plateau margin in the Ladakh and Zanskar Ranges, NW Himalaya, India. Recently reported 10Be-derived bedrock incision rates of up to 3 mm/yr suggest locally focused fast incision that contrasts with the low (~0.02 mm/yr) denudation rates of this dry high-altitude mountain desert. We combine Optically Stimulated Luminescence (OSL) and 10Be dating techniques, provenance analyses and morphometric analyses of digital elevation models (DEMs), in order to understand the Quaternary evolution of the region and to estimate sediment storage and residence times. We present the first OSL-derived dataset of fluvial fill terrace ages in the lower Zanskar gorge, a major tributary of the upper Indus River. These data are complemented by new 10Be exposure ages from fluvially polished surfaces and a 10Be depth profile of a fluvial terrace situated at the Zanskar-Indus confluence. Our data indicate at least two cycles of aggradation and re-incision. OSL ages from a terrace level 35 m above the river point to a phase of aggradation between 50 ka and 20 ka, which we attribute either to a late- or postglacial sediment pulse from the Zanskar headwaters, and/or to natural damming downstream. Preliminary results for the 10Be depth profile from the top of a terrace ~160 m above river level suggest a deposition age of > 100 ka, dating an older aggradation cycle. This higher terrace level is also present in the

  5. Disentailment and agricultural intensification of river banks: the vega de Aranjuez; Desarmortizacion e intensificaion agraria de riberas fluviales: La vega de Aranjuez

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Garcia, M. J.; Mateu Belles, J. F.


    In Spain, successive appropriations by the state of river flood terraces which had previously been in communal or private hands led to apart from notorious social repercussions-increased pressure on the limited water resources, loss of the diversity of agricultural uses as practices became more uniform, and accelerated destruction of the few remaining fragments or riverside woodlands. later water laws (1866 and 1879) and court rulings permitted the aggregation of adjacent fields on river margins, the disappearance of customary uses (including settled and transhumant grazing) and the expansion of horticulture and other intensive arable crops. (Author) 8 refs.

  6. Active tectonics in the NW-German Basin: Evidence from correlations between the modern landscape and deep geological structures (Lower Saxony, river Hunte) (United States)

    Szeder, T.; Sirocko, F.


    The catchment basin of the river Hunte (NW-German Basin, Lower Saxony) was studied on a mesoscale (length of ˜90 km) to investigate if tectonic movements in the upper crust influence modern landscape formation. Crustal movements led to upwarping of the Lower Weichselian Terrace above the transition zone of a major crustal boundery of the NW-German Basin (Lower Saxony Basin/Pompeckj Block) with an average vertical velocity of about 0,5 mm/a over the last 12 ka. The Lower Weichselian Terrace and the Hunte catchment basin are narrowest at the same position. Even the Holocene Alluvial Plain is affected by active tectonics. The Holocene Alluvial Plain is narrower and shows a negative gradient directly above a deep seated Permian salt pillow which can be traced over a vertical distance of about 4000 m as an anticline structure to the uppermost Tertiary (100 m b.s.l.). The spatial similarity of fluvial anomalies with anomalies of the geological subground indicates that crustal movements still exercise control on fluvial dynamics and are coupled to the geological predesign. Basin subsidence is thought to have triggered primarily the aggradation of the Lower Weichselian Terrace, because there is an accordance between the mean recent velocity of basin subsidence (˜-0,21 mm/a), calculated from repeated geodetic fine levelling and the mean sedimentation rate of the Lower Weichselian Terrace (˜0,2--0,4 mm/a). In addition, sedimentation rates of the Lower Weichselian Terrace were nearly constant over a time span of about 35 ka (˜47--12 ka BP). During these times the climate has changed rapidly over Northern Europe (Dansgaard-Oeschger Cycles) which affected river morphology, hydrology and sediment supply. However, the observation that no change of the mean sedimentation rate is observable indicates a long term subsiding tendency which enables accumulation of longer fluvial sequences independent of short scale climatic fluctuations. Most likely northward tilting of the NW

  7. Assessment of the predisposing factors for shallow landslides activation in terraced areas: the case of the Rupinaro catchment, Liguria (northwestern Italy). (United States)

    Cignetti, Martina; Godone, Danilo; Giordan, Daniele


    The shallow landslides occurrence is strongly correlated with climatic conditions and environmental settings. In the Liguria region (northwestern Italy), the landscape presents an ancient human intervention represented by terraces and, in the last century, by a general overbuilding, both in the few flat areas and in the steep slope hinterland. From the twentieth century, the progressive abandonment of agriculture generated a lack of maintenance of terraced areas, which associated to the urban and the road net development, supported the slope susceptibility to instability. This makes the assessment of the predisposing factors for shallow landslides a multidisciplinary task, combining natural and man-made issues. In this work, we try to define all the main predisposing factors of the Rupinaro catchment (southeast Liguria). We operate starting from a high-resolution Digital Terrain Model (DTM) supplied by an airborne LiDAR survey carried out after the autumn 2014 rainfall events. From this DTM, we mapped a total amount of 96 landslides in the study area. Then, we implemented a classification methodology based on a simple parametric score. In GIS environment we overlaid several layers: i) lithological and hydrogeological map, ii) slope iii) aspect, iv) the land use information, available by the CORINE land cover, and iv) the presence of terraces. Each spatial data was than reclassified according a numerical code. The sum, by raster math, of these factors provided an overall score raster for the entire basin. This method allows the characterization of the entire watershed, gathering all the predisposing factors for the shallow landslides activation. A categorization of the landslides area mapped from the DTM and stored in a vector layer has been made. In particular, we estimated the most frequent code within each landslide polygon, obtaining a representative data of the most influential factors that triggered shallow landslides. The results showed the prevalent

  8. Soil abandonment in artificial soil terraces in marginal areas. Preliminary results of a case of water shortage effect in soils from Sultanate of Oman. (United States)

    Saadi, Sara Kalifah Al; Kindi, Samaya Salim Al; Pracejus, Bernhard; Moraetis, Daniel


    Soil abandonment is taking place in marginal land areas in Sultanate of Oman. Artificial soil terraces in high elevation rocky mountainous areas left without agricultural activities due to water shortage. Soil terraces have been established approximately 700 years ago and constitute a significant part of the Oman cultural and natural heritage. The present study investigates the soil state in those areas and seeks the possible reasons for the land abandonment. Questionnaires were prepared to interview the opinion of the local people. In addition, meteorological data were gathered to analyze the rain patterns in the area and most importantly, six soil profiles in two different areas in marginal rocky areas of Oman were sampled. The soils are in artificial terraces in Wijma and Hadash villages with elevation of 1247 and 1469 m respectively at mountainous slopes of 20 to 45 degrees. Most of the land was abandoned the last 20 years, while one terrace had agriculture activity 3 years ago. The questioners and interviews showed that water shortage was the reason of land abandonment. The rain patterns show a reduction of annual precipitation at least the last 10 years of available metrological data in the area. The total soil depth in the six soil profiles was between 33 to 70 cm. The main horizons include AC and C and there was a characteristic hard soil horizon in most of the soil profiles with accumulation of carbonate minerals (caliche). The soil pH was mainly alkaline between 7.5 to 8.1 and the electrical conductivity range between 42 to 859 μS/cm. A horizonization in electrical conductivity showed more dissolved solids in lower horizons compare to the upper 10 cm of the soil and this was coinciding with the hard layers in lower soil profiles. It appeared that several hundred years (or maximum 1000 years) old soils showed the development of hard soil layers which are characteristic in arid areas. The upper soil layers showed low conductivity probably due to surface

  9. Exposure to secondhand smoke in terraces and other outdoor areas of hospitality venues in eight European countries.

    Directory of Open Access Journals (Sweden)

    Maria J López

    Full Text Available BACKGROUND: Outdoor secondhand smoke (SHS concentrations are usually lower than indoor concentrations, yet some studies have shown that outdoor SHS levels could be comparable to indoor levels under specific conditions. The main objectives of this study were to assess levels of SHS exposure in terraces and other outdoor areas of hospitality venues and to evaluate their potential displacement to adjacent indoor areas. METHODS: Nicotine and respirable particles (PM2.5 were measured in outdoor and indoor areas of hospitality venues of 8 European countries. Hospitality venues of the study included night bars, restaurants and bars. The fieldwork was carried out between March 2009 and March 2011. RESULTS: We gathered 170 nicotine and 142 PM2.5 measurements during the study. The median indoor SHS concentration was significantly higher in venues where smoking was allowed (nicotine 3.69 µg/m3, PM2.5: 120.51 µg/m3 than in those where smoking was banned (nicotine: 0.48 µg/m3, PM2.5: 36.90 µg/m3. The median outdoor nicotine concentration was higher in places where indoor smoking was banned (1.56 µg/m3 than in venues where smoking was allowed (0.31 µg/m3. Among the different types of outdoor areas, the highest median outdoor SHS levels (nicotine: 4.23 µg/m3, PM2.5: 43.64 µg/m3 were found in the semi-closed outdoor areas of venues where indoor smoking was banned. CONCLUSIONS: Banning indoor smoking seems to displace SHS exposure to adjacent outdoor areas. Furthermore, indoor settings where smoking is banned but which have a semi-closed outdoor area have higher levels of SHS than those with open outdoor areas, possibly indicating that SHS also drifts from outdoors to indoors. Current legislation restricting indoor SHS levels seems to be insufficient to protect hospitality workers--and patrons--from SHS exposure. Tobacco-free legislation should take these results into account and consider restrictions in the terraces of some hospitality venues to ensure

  10. Exposure to secondhand smoke in terraces and other outdoor areas of hospitality venues in eight European countries. (United States)

    López, Maria J; Fernández, Esteve; Gorini, Giuseppe; Moshammer, Hanns; Polanska, Kinga; Clancy, Luke; Dautzenberg, Bertrand; Delrieu, Agnes; Invernizzi, Giovanni; Muñoz, Glòria; Precioso, Jose; Ruprecht, Ario; Stansty, Peter; Hanke, Wojciech; Nebot, Manel


    Outdoor secondhand smoke (SHS) concentrations are usually lower than indoor concentrations, yet some studies have shown that outdoor SHS levels could be comparable to indoor levels under specific conditions. The main objectives of this study were to assess levels of SHS exposure in terraces and other outdoor areas of hospitality venues and to evaluate their potential displacement to adjacent indoor areas. Nicotine and respirable particles (PM2.5) were measured in outdoor and indoor areas of hospitality venues of 8 European countries. Hospitality venues of the study included night bars, restaurants and bars. The fieldwork was carried out between March 2009 and March 2011. We gathered 170 nicotine and 142 PM2.5 measurements during the study. The median indoor SHS concentration was significantly higher in venues where smoking was allowed (nicotine 3.69 µg/m3, PM2.5: 120.51 µg/m3) than in those where smoking was banned (nicotine: 0.48 µg/m3, PM2.5: 36.90 µg/m3). The median outdoor nicotine concentration was higher in places where indoor smoking was banned (1.56 µg/m3) than in venues where smoking was allowed (0.31 µg/m3). Among the different types of outdoor areas, the highest median outdoor SHS levels (nicotine: 4.23 µg/m3, PM2.5: 43.64 µg/m3) were found in the semi-closed outdoor areas of venues where indoor smoking was banned. Banning indoor smoking seems to displace SHS exposure to adjacent outdoor areas. Furthermore, indoor settings where smoking is banned but which have a semi-closed outdoor area have higher levels of SHS than those with open outdoor areas, possibly indicating that SHS also drifts from outdoors to indoors. Current legislation restricting indoor SHS levels seems to be insufficient to protect hospitality workers--and patrons--from SHS exposure. Tobacco-free legislation should take these results into account and consider restrictions in the terraces of some hospitality venues to ensure effective protection.

  11. Mediterranean Sea response to climate change in an ensemble of twenty first century scenarios (United States)

    Adloff, Fanny; Somot, Samuel; Sevault, Florence; Jordà, Gabriel; Aznar, Roland; Déqué, Michel; Herrmann, Marine; Marcos, Marta; Dubois, Clotilde; Padorno, Elena; Alvarez-Fanjul, Enrique; Gomis, Damià


    The Mediterranean climate is expected to become warmer and drier during the twenty-first century. Mediterranean Sea response to climate change could be modulated by the choice of the socio-economic scenario as well as the choice of the boundary conditions mainly the Atlantic hydrography, the river runoff and the atmospheric fluxes. To assess and quantify the sensitivity of the Mediterranean Sea to the twenty-first century climate change, a set of numerical experiments was carried out with the regional ocean model NEMOMED8 set up for the Mediterranean Sea. The model is forced by air-sea fluxes derived from the regional climate model ARPEGE-Climate at a 50-km horizontal resolution. Historical simulations representing the climate of the period 1961-2000 were run to obtain a reference state. From this baseline, various sensitivity experiments were performed for the period 2001-2099, following different socio-economic scenarios based on the Special Report on Emissions Scenarios. For the A2 scenario, the main three boundary forcings (river runoff, near-Atlantic water hydrography and air-sea fluxes) were changed one by one to better identify the role of each forcing in the way the ocean responds to climate change. In two additional simulations (A1B, B1), the scenario is changed, allowing to quantify the socio-economic uncertainty. Our 6-member scenario simulations display a warming and saltening of the Mediterranean. For the 2070-2099 period compared to 1961-1990, the sea surface temperature anomalies range from +1.73 to +2.97 °C and the SSS anomalies spread from +0.48 to +0.89. In most of the cases, we found that the future Mediterranean thermohaline circulation (MTHC) tends to reach a situation similar to the eastern Mediterranean Transient. However, this response is varying depending on the chosen boundary conditions and socio-economic scenarios. Our numerical experiments suggest that the choice of the near-Atlantic surface water evolution, which is very uncertain in

  12. Tributary debris fans and the late Holocene alluvial chronology of the Colorado River, eastern Grand Canyon, Arizona (United States)

    Hereford, R.; Thompson, K.S.; Burke, K.J.; Fairley, H.C.


    Bouldery debris fans and sandy alluvial terraces of the Colorado River developed contemporaneously during the late Holocene at the mouths of nine major tributaries in eastern Grand Canyon. The age of the debris fans and alluvial terraces contributes to understanding river hydraulics and to the history of human activity along the river, which has been concentrated on these surfaces for at least two to three millennia. Poorly sorted, coarse-grained debris-flow deposits of several ages are interbedded with, overlie, or are overlapped by three terrace-forming alluviums. The alluvial deposits are of three age groups: the striped alluvium, deposited from before 770 B.C. to about A.D. 300; the alluvium of Pueblo II age deposited from about A.D. 700 to 1200; and the alluvium of the upper mesquite terrace, deposited from about A.D. 1400 to 1880. Two elements define the geomorphology of a typical debris fan: the large, inactive surface of the fan and a smaller, entrenched, active debris-flow channel and fan that is about one-sixth the area of the inactive fan. The inactive fan is segmented into at least three surfaces with distinctive weathering characteristics. These surfaces are conformable with underlying debris-flow deposits that date from before 770 B.C. to around A.D. 660, A.D. 660 to before A.D. 1200, and from A.D. 1200 to slightly before 1890, respectively, based on late-19th-century photographs, radiocarbon and archaeologic dating of the three stratigraphically related alluviums, and radiocarbon dating of fine-grained debris-flow deposits. These debris flows aggraded the fans in at least three stages beginning about 2.8 ka, if not earlier in the late Holocene. Several main-stem floods eroded the margin of the segmented fans, reducing fan symmetry. The entrenched, active debris-flow channels contain deposits debris fans at the mouth of the channel adjacent to the river. Early and middle Holocene debris-flow and alluvial deposits have not been recognized, as they were

  13. 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 (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.


    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.

  14. Twenty-Sixth Symposium (International) on Combustion, Volume 1. (United States)


    Fundamental Aspects of Combustion, Oxford University Press, New York, 1993, p. 81. 12. Ross, H. D., Miller, F. J., Schiller, D. N., and Sirig- nano , W...Mech. 48:547-591 (1971). 2. Lazaro , B. J. and Lasheras, J. C, Phys. Fluids 1:1035 (1989). 3. Kiger, K. T. and Lasheras, J. C, Twenty-Fifth Sympo

  15. Proceedings of the Twenty Second Nordic Seminar on Computational Mechanics

    DEFF Research Database (Denmark)

    This book contains the proceedings of the Twenty Second Nordic Seminar on Computational Mechanics (NSCM22), taking event 22-23 October 2009 at Aalborg University, Denmark. The papers presented at the Optimization Seminar in Honour of Niels Olhoff, held 21 October 2009 at Aalborg University, Denmark...

  16. The Work Place of the Early Twenty-First Century. (United States)

    Brown, James M.


    Major issues affecting the workplace of the twenty-first century include productivity growth, globalization, resistance to change, worker alienation, and telecommunications. Opposing views of technology are that (1) it will improve the economy and create jobs or (2) the majority of new jobs will not require high skills. (SK)

  17. Educators Guide to Free Filmstrips. Twenty-Third Edition. (United States)

    Horkheimer, Mary Foley, Comp.; Diffor, John C., Comp.

    A total of 453 titles of filmstrips, slide sets, and sets of transparencies available free of charge to educators are listed in this guide. More than 20,000 separate frames are offered from 95 sources. Twenty of the filmstrips may be retained permanently by the borrower. The films cover topics in the fields of accident prevention, aerospace…

  18. Membership, Belonging, and Identity in the Twenty-First Century (United States)

    Motteram, Gary


    This article takes a case study approach to exploring membership, belonging, and identity amongst English language teachers in the twenty-first century. It explores findings from two membership surveys conducted for the International Association of Teachers of English as a Foreign Language (IATEFL), and considers the impact of recommendations…

  19. Tall Fescue for the Twenty-first Century (United States)

    Tall Fescue for the Twenty-first Century is a comprehensive monograph by experts from around the world about the science of tall fescue [Lolium arundinaceum (Schreb.) Darbysh. = Schedonorus arundinaceus (Schreb.) Dumort., formerly Fes¬tuca arundinacea Schreb. var. arundinacea] and its applications. ...

  20. Powering into the twenty-first century [Singapore Power Limited

    Energy Technology Data Exchange (ETDEWEB)



    To meet the challenges of the twenty-first century power industry, Singapore Power was incorporated as a commercial entity in October 1995. As the leading energy company in Singapore, SP continues to invest heavily in infrastructure development to improve its service efficiency and reliability, and to maintain its reputation as one of the world`s best power suppliers. (UK)

  1. Afterword: Victorian Sculpture for the Twenty-First Century

    Directory of Open Access Journals (Sweden)

    David J. Getsy


    Full Text Available Commenting on the directions proposed by this issue of '19', the afterword discusses the broad trends in twenty-first century studies of Victorian sculpture and the opportunity for debate arising from the first attempt at a comprehensive exhibition.

  2. Membership, Belonging, and Identity in the Twenty-First Century (United States)

    Motteram, Gary


    This article takes a case study approach to exploring membership, belonging, and identity amongst English language teachers in the twenty-first century. It explores findings from two membership surveys conducted for the International Association of Teachers of English as a Foreign Language (IATEFL), and considers the impact of recommendations…

  3. Blended Instruction: The Roaring Twenties Meets (United States)

    Waldron, Diane L.


    The action research study described in this report outlines the design and implementation of a unit of blended instruction in a traditional high school English classroom. Twenty technical high school students in an 11th grade Honors English class engaged in a variety of internet-based activities in conjunction with traditional learning activities…

  4. Twenty-One: a baseline for multilingual multimedia retrieval

    NARCIS (Netherlands)

    Jong, de Franciska; Hiemstra, Djoerd; Jong, de Franciska; Netter, Klaus


    In this paper we will give a short overview of the ideas underpinning the demonstrator developed within the EU-funded project Twenty-One; this system provides for the disclosure of information in a heterogeneous document environment that includes documents of different types and languages. As part o

  5. Twenty years of physics at MAMI -What did it mean?

    Energy Technology Data Exchange (ETDEWEB)

    Mecking, B.A. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)


    The development over the last twenty years of the physics program and the experimental facilities at the Mainz Microtron MAMI will be reviewed. Ground-breaking contributions have been made to the development of experimental techniques and to our understanding of the structure of nucleons and nuclei. (orig.)

  6. The Presidential Platform on Twenty-First Century Education Goals (United States)

    Tichnor-Wagner, Ariel; Socol, Allison Rose


    As social and economic problems change, so do the goals of education reformers. This content analysis of presidential debates transcripts, state of the union addresses, and education budgets from 2000 to 2015 reveals the ways in which presidents and presidential candidates have framed education goals thus far in the twenty-first century. Using…

  7. Twenty years of physics at MAMI --What did it mean?

    Energy Technology Data Exchange (ETDEWEB)

    Bernhard Mecking


    The development over the last twenty years of the physics program and the experimental facilities at the Mainz Microtron MAMI will be reviewed. Ground-breaking contributions have been made to the development of experimental techniques and to our understanding of the structure of nucleons and nuclei.

  8. The Work Place of the Early Twenty-First Century. (United States)

    Brown, James M.


    Major issues affecting the workplace of the twenty-first century include productivity growth, globalization, resistance to change, worker alienation, and telecommunications. Opposing views of technology are that (1) it will improve the economy and create jobs or (2) the majority of new jobs will not require high skills. (SK)

  9. Twenty-One: a baseline for multilingual multimedia retrieval

    NARCIS (Netherlands)

    Unknown, [Unknown; Hiemstra, Djoerd; de Jong, Franciska M.G.; Netter, Klaus


    In this paper we will give a short overview of the ideas underpinning the demonstrator developed within the EU-funded project Twenty-One; this system provides for the disclosure of information in a heterogeneous document environment that includes documents of different types and languages. As part o

  10. Digital earth applications in the twenty-first century

    NARCIS (Netherlands)

    de By, R.A.; Georgiadou, P.Y.


    In these early years of the twenty-first century, we must look at how the truly cross-cutting information technology supports other innovations, and how it will fundamentally change the information positions of government, private sector and the scientific domain as well as the citizen. In those

  11. Book for do-it-yourselfers. Experience with and advice on the reconstruction of terraced houses. 2. ed. Selbstbau-Fibel. Erfahrungen und Hinweise zum Umbau von Reihenhaeusern

    Energy Technology Data Exchange (ETDEWEB)

    Laage, G.; Bubolz, W.; Eith, L.; Feenders, T.; Marlow, K.; Niemeyer, U.


    Experience gathered and problems encountered in the self-reconstruction of terraced houses form the core of this do-it-yourself book. It derives advice and decision aids for planning and executing reconstruction work from practice. The aim is to assure the qualitative improvement of the interior of the house and its outward appearance. The chapters deal with: Experiences (motives for wanting house reconstruction, planning, self-construction, material purchase); space in front of the house (entrance, maindoor, vestibule); rooms in the house; attached greenhouses (historical models, ecological importance); extension works in garret storeys; bathroom and toilet; windows (material, design, glazing); thermal protection (energy conservation, insulation, joint packing, creeper plants on house fronts); wood protection (crash course); behind the house (terrace, shed, bower); construction law, protection against accidents, limits of self-construction, technical literature. (HWJ).

  12. Nano-structure and optical properties (plasmonic) of graded helical square tower-like (terraced) Mn sculptured thin films (United States)

    Savaloni, Hadi; Fakharpour, Mahsa; Siabi-Garjan, Araz; Placido, Frank; Babaei, Ferydon


    Graded helical square tower-like terraced sculptured Mn thin films (GHSTTS) are produced in three stages with different number of arms using oblique angle deposition together with rotation of substrate holder about its surface normal, plus a shadowing block fixed at the centre of the substrate holder. The structural characterization of the produced samples was obtained using field emission scanning electron microscope (FESEM) and atomic force microscope (AFM). Results showed a structural gradient with distance from the edge of the shadowing block, which in turn is responsible for the decrease in the volume of void fraction and increase of grain size. Plasmon absorption peaks observed in the optical analysis of these nano-structures showed that their wavelength region and intensity depend on the polarization and the incident angle of light, as well as the distance from the edge of the shadowing block. According to our model and discrete dipole approximation (DDA) calculations, when the number of parallel nano-rods of different lengths and radii are increased the peak in the spectrum shifts to shorter wavelengths (blue shift). Also when the diameters of the nano-rods increases (a situation that occurs with increasing film thickness) the results is again a blue shift in the spectrum. The presence of defects in these sculptured structures caused by the shadowing effect is predicted by the theoretical DDA investigation of their optical spectra. Good agreement is obtained between our theoretical results and the experimental observations in this work.

  13. Landscape Change in Mediterranean Farmlands: Impacts of Land Abandonment on Cultivation Terraces in Portofino (Italy and Lesvos (Greece

    Directory of Open Access Journals (Sweden)

    Sluis Theo Van Der


    Full Text Available The Mediterranean landscape has been rapidly changing over the past decades. Many regions saw a population decline, which resulted in changing land use, abandonment of marginal lands and colonisation by shrubs and tree species. Typical features like farming terraces, olive yards, and upland grasslands have been decreasing over the past 50 years. This results in a declining biodiversity and loss of traditional Mediterranean landscapes. In this paper we assess the landscape changes that took place in two areas, in Portofino, on the Italian Riviera, and Lesvos, a Greek island near the Turkish coast. We compared land use maps and aerial photographs over the past decades to quantify the land use changes in these two areas. Additional information was acquired from farmers’ interviews and literature. We found that changes are related to societal changes in the appraisal of agricultural land uses, and to the urban expansion, tourism and recreation. These diffuse processes are a result of policy measures and autonomous societal transformations. This is confirmed by the results of two interview surveys: between 1999 and 2012 agricultural land use in Portofino regional Park and buffer zone further marginalised, and the associated landscape changes are perceived as a substantial loss of character and identity. This problem is emblematic for large parts of the Mediterranean. Comparing different landscapes reveal similar processes of landscape change, which can be related to similar driving forces. Based on such comparisons, we learn about possible trajectories of change, and ask for a comprehensive approach to land use management.


    Institute of Scientific and Technical Information of China (English)

    王小燕; 邱维理; 张家富; 李容全; 周力平


    Because of its complex history,the Yellow River is a good case for fluvial geomorphology studies.The Jinshaan Gorge is one of the key parts to understand the evolution of the Yellow River.Since 1922,researchers have made great progress in the study of the evolution of the Yellow River in the Jinshaan Gorge area.But there are some disputes still remained about the Tangxian Surface,an erosion surface formed in the Miocene and Pliocene,and the alluvium on it.The main divarication is whether the Tangxian Surface is a terrace of the Yellow River or the alluvium on the Tangxian Surface is formed by the ancient Yellow River.Baode-Fugu area,located in the north part of the Jinshaan Gorge,is famous for the Neogene red clay sediment in which Hipprion fauna is unearthed.The recent studies of red clay offer a chronological data to discuss the age of both the red clay,other contemporaneous sediment and the underneath erosion surface of Tangxian Stage.The present paper is based on the survey of eighteen sediment outcrops on the Tangxian Surface in the BaodeFugu area.Twenty one samples were collected from gravel layers for sediment analysis.A topographic profile across the Yellow River shows that there is a wide bedrock valley stretching along the modern Yellow River,which is about 170m above the river level.According to the previous magnetostratigraphic studies of the red clay and fluvial sediment,the Tangxian Surface was formed at least 8.OMa ago.Gravel statistic result shows that the gravel sitting on the Tangxian Surface is > 1.5 in the complexity index of components and is characterized by an average roundness of ca.2 or >2,i.e.sub-rounded and rounded,with a variance of >0.5.The rock type of the gravels indicates a mixture of distant and local source.Combining the evidences above,it is reasonable to conclude that there used to be a river flowing along a similar course direction of modern Yellow River in this region during the Middle Miocene.Though it is much smaller

  15. The effect of lithology on valley width, terrace distribution, and coarse sediment provenance in a tectonically stable catchment with flat-lying stratigraphy (United States)

    Amanda Keen-Zebert,; Hudson, Mark R.; Stephanie L. Shepherd,; Evan A. Thaler,


    How rock resistance or erodibility affects fluvial landforms and processes is an outstanding question in geomorphology that has recently garnered attention owing to the recognition that the erosion rates of bedrock channels largely set the pace of landscape evolution. In this work, we evaluate valley width, terrace distribution, and sediment provenance in terms of reach scale variation in lithology in the study reach and discuss the implications for landscape evolution in a catchment with relatively flat2

  16. A contribution to the characterisation of Iron Age agrarian spaces: documentation and pollen analysis of a possible cultivation terrace in the castro of Follente (Caldas de Reis, Pontevedra)


    López Sáez, José Antonio; López Merino, Lourdes; Pérez Díaz, Sebastián; Parcero-Oubiña, César; Criado-Boado, Felipe


    A series of samples extracted from the stratigraphic profile of a possible cultivation terrace located in the surroundings of an Iron Age hillfort in Galicia were used for pollen analysis. The combined results of both the stratigraphic information and the pollen analysis allow the proposal of a sequence of landscape transformation where, rather unexpectedly, the greater intensification in the use of the area, corresponding to the occupation of the hillfort and the construction of cultivation ...

  17. Maritime surroundings with geothermal energy. Kiel' conveying terraces put on a sustainable power supply; Maritimes Wohnen mit Erdwaerme. Kieler Foerdeterrassen setzen auf nachhaltige Energieversorgung

    Energy Technology Data Exchange (ETDEWEB)

    Hartmann, Frank


    In November 2009, the first stage of construction of conveying terraces was completed with an innovative energy concept in Holtenau (Federal Republic of Germany). After an operating time of more than three years, there is a positive experience report exceeding the theoretical expectations. Within this project heat from solar collectors and brine-to-water heat pumps form the basis of a heat contracting for high-value apartments with sea views.

  18. Visual privacy and family intimacy: a case study of Malay inhabitants living in two-storey low-cost terrace housing


    Ahmad Hariza Hashim; Zaiton Abdul Rahim; Sharifah Norazizan Syed Abdul Rashid; Nurizan Yahaya


    The authors report on a study of visual privacy, family intimacy, and building elements of two-storey low-cost terrace housing in an urban area in Malaysia. They examine behavioural and physical regulating mechanisms used to achieve privacy among Malay Muslim inhabitants of the housing units studied. They also look at the consequences of the lack of privacy on the inhabitants over a period of time. Their findings support the premise that cultural values influence housing and that religious un...

  19. Disentangling Values in the Interrelations between Cultural Ecosystem Services and Landscape Conservation—A Case Study of the Ifugao Rice Terraces in the Philippines

    Directory of Open Access Journals (Sweden)

    Bianca Tilliger


    Full Text Available In the past few years, there has been a growing amount of research on economic quantifications and valuations of ecosystem services (ES in agricultural systems. However, little attention has been given to cultural ESs (CES in general and their link to the landscape in particular. This paper tries to tackle this gap with a case study on the Ifugao Rice Terraces of the Philippines. The study aims to understand the interrelations between the different CESs and their relationships with the landscape. Besides contributing to knowledge about the degradation of the rice terraces, this study was conducted in order to discuss at a theoretical level how CESs and their relationship with the landscape must be addressed in ES management and policy decisions. The methodological approach includes a combination of semi-structured interviews (n = 60 and a perception survey (n = 66. The results reveal that CESs, apart from being interrelated, are also responsible for and affected by the degradation of the rice terraces, which is why they are important factors to consider in ecosystem conservation. This paper finally provides policy recommendations for the empirical case and demonstrates the importance of connecting CES analysis with landscape studies looking at agricultural systems.

  20. Resilience and adaptability of rice terrace social-ecological systems: a case study of a local community's perception in Banaue, Philippines

    Directory of Open Access Journals (Sweden)

    Adam C. Castonguay


    Full Text Available The social-ecological systems of rice terraces across Southeast Asia are the result of centuries of long-term interactions between human communities and their surrounding ecosystems. Processes and structures in these systems have evolved to provide a diversity of ecosystem services and benefits to human societies. However, as Southeast Asian countries experience rapid economic growth and related land-use changes, the remaining extensive rice cultivation systems are increasingly under pressure. We investigated the long-term development of ecosystem services and the adaptive capacity of the social-ecological system of rice terrace landscapes using a case study of Banaue (Ifugao Province, Northern-Luzon, Philippines. A set of indicators was used to describe and assess changes in the social-ecological state of the study system. The resilience of the rice terraces and the human communities that maintain them was examined by comparing the current state of the system with results from the literature. Our findings indicate that, although the social-ecological system has not yet shifted to an alternative state, pressures are increasing and some cultural ecosystem services have already been lost.

  1. Planning Method of Eco-environment Restoration Based on Enlarging Terrace and De-farming in Loess Hilly Region——A Case Study of Yangou Catchment

    Institute of Scientific and Technical Information of China (English)

    Lijuan; DANG; Yong; XU


    After expatiating the guiding ideology,contents,standards and principles of eco-environment restoration based on enlarging terrace and de-farming,this paper discussed the planning method and technical flow of enlarging terrace and garden plot in a small catchment of loess hilly region by means of GIS spatial analysis technology,and then the planning method was applied in Yangou catchment.The result showed that it is practicabl,and the areas of newly-built terrace and garden plot in Yangou catchment are at least 295.06 and 4.61 hm2,so that the areas of basic farmland and garden plot reach 359.23 and 622.69 hm2.After the land use structure is regulated,the forest coverage is 48.87%,and the permanent vegetation coverage is about 75% in Yangou catchment,while sediment reduction benefit is above 80% in slope land.In agricultural development,Yangou catchment can yield 1 645.13 tons of food supplies,above 9 340 tons of apples,and can feed 7 500 sheep every year.

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

    Lwin, A.; Khaing, M. M.


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

  3. Water-quality data for the Russian River Basin, Mendocino and Sonoma Counties, California, 2005-2010 (United States)

    Anders, Robert; Davidek, Karl; Stoeckel, Donald M.


    Since 2003, the U.S. Geological Survey, in cooperation with the Sonoma County Water Agency, has been collecting chemical, microbiological, and isotopic data from surface-water and groundwater sites in Mendocino and Sonoma Counties, California. The investigation is being conducted to determine water-quality baseline conditions for the Russian River during the summer months and to characterize the water-quality in the area of the Sonoma County Water Agency's water-supply facility where Russian River water is diverted and treated by riverbank filtration. This report is a compilation of the hydrologic and water-quality data collected from 14 Russian River sites, 8 tributary sites, 1 gravel-terrace pit site, 14 groundwater wells, and a wastewater treatment plant between the city of Ukiah and the town of Duncans Mills for the period August 2005 through October 2010.

  4. 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)


    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.

  5. Magnetic Properties of a Fluvial Chronosequence From the Eastern Wind River Range, Wyoming (United States)

    Quinton, E. E.; Dahms, D. E.; Geiss, C. E.


    In order to constrain the rate of magnetic enhancement in glacial fluvial sediments, we sampled modern soils from eight fluvial terraces in the East Wind River Range in Wyoming. Soil profiles up to 1.2 meters deep were described in the field and sampled in five cm intervals from a series of hand-dug pits or natural river-bank exposure. The age of the studied profiles are estimated to range from >600 ka to modern. They include Sacagawea Ridge, Bull Lake and Pinedale-age fluvial terraces as well as one Holocene profile. To characterize changes in magnetic properties we measured low-field magnetic susceptibility, anhysteretic remanent magnetization, isothermal remanent magnetization and S-ratios for all, and hysteresis loops for a selected sub-set of samples. Our measurements show no clear trend in magnetic enhancement with estimated soil age. The observed lack of magnetic enhancement in the older soils may be due to long-term deflation, which continuously strips off the magnetically enhanced topsoil. It is also possible that the main pedogenic processes, such as the development of well-expressed calcic horizons destroy or mask the effects of long-term magnetic enhancement.

  6. Holocene delta plain development in the Song Hong (Red River) delta, Vietnam (United States)

    Funabiki, Ayako; Haruyama, Shigeko; Quy, Nguyen Van; Hai, Pham Van; Thai, Dinh Hung


    Holocene delta plain development was investigated based on three sediment cores analyzed in detail from the Song Hong (Red River) delta plain in Vietnam. Two cores (DA and PD) from the western delta plain showed both the landward limit of the transgressive estuarine system in the valley incised during the last glacial maximum and floodplain evolution since the middle Holocene. On the other hand, a core (TL) from the eastern delta plain revealed a Pleistocene terrace buried under the deltaic sediments and a slow accumulation rate compared with that in the west. At 8 cal ky BP, the shoreline migrated very close to the present Hanoi city area, and the sedimentary environment changed to tidal flat or salt marsh. Hanoi city marks the northern limit of shoreline transgression. The mangrove swamp expanded from 8 to 5 cal ky BP to the landward limit of the delta plain. Subsequently, the shoreline migrated seaward as a result of delta progradation and sea-level lowering. From 5 cal ky BP, the emerged area evolved into a floodplain and natural levees formed along the abandoned river channels on the western delta plain, but at 2 cal ky, archeological sites indicate that the Holocene terrace in the eastern delta plain was still inundated.

  7. A luminescence dating study of the sediment stratigraphy of the Lajia Ruins in the upper Yellow River valley, China (United States)

    Zhang, Yuzhu; Huang, Chun Chang; Pang, Jiangli; Zhou, Yali; Zha, Xiaochun; Wang, Longsheng; Zhou, Liang; Guo, Yongqiang; Wang, Leibin


    Pedo-sedimentological fieldwork were carried out in the Lajia Ruins within the Guanting Basin along the upper Yellow River valley. In the eolian loess-soil sections on the second river terrace in the Lajia Ruins, we find that the land of the Qijia Culture (4.20-3.95 ka BP) are fractured by several sets of earthquake fissures. A conglomerated red clay covers the ground of the Qijia Culture and also fills in the earthquake fissures. The clay was deposited by enormous mudflows in association with catastrophic earthquakes and rainstorms. The aim of this study is to provide a luminescence chronology of the sediment stratigraphy of the Lajia Ruins. Eight samples were taken from an eolian loess-soil section (Xialajia section) in the ruins for optically stimulated luminescence (OSL) dating. The OSL ages are in stratigraphic order and range from (31.94 ± 1.99) ka to (0.76 ± 0.02) ka. Combined OSL and 14C ages with additional stratigraphic correlations, a chronological framework is established. We conclude that: (1) the second terrace of the upper part of Yellow River formed 35.00 ka ago, which was followed by the accumulation of the eolian loess-soil section; and (2) the eolian loess-soil section is composed of the Malan Loess of the late last glacial (MIS-2) and Holocene loess-soil sequences.

  8. Soil Erosion under Different Land Use Types and Zones of Jinsha River Basin in Yunnan Province,China

    Institute of Scientific and Technical Information of China (English)

    YANG Zisheng; LIANG Luohui


    Severe soil erosion in the middle and upper reaches of Yangtze River has been regarded as a major environmental problem. The on-site impact of soil erosion on agricultural production and the off-site impact on floods and sedimentation in Yangtze Rive are well known. A quantitative assessment of soil erosion intensity is still scanty for developing appropriate soil erosion control measures for different land use types and zones in this region. This article constructs a localized USLE and estimates the average soil loss in the Jinsha River Region in Yunnan Province, one of the priority areas for soil erosion control in the middle and upper reaches of Yangtze River. The estimation is done under different land uses and zones in this basin. The estimation shows that while soil erosion in the cultivated land is the most severe, 36~40% of the garden and forest land suffers from soil erosion of various degrees due to lack of ground cover and other factors. Soil erosion in the pasture is modest when the ground cover is well maintained. It also confirmed that terracing can reduce soil erosion intensity significantly on the cultivated land. Research findings suggest that sufficient attention must be paid to regeneration of the ground cover in reforestation programs. In addition to mass reforestation efforts, restoration of grassland and terracing of the cultivated land should also play an important role in erosion control.

  9. Proceedings of the Twenty-Third Annual Software Engineering Workshop (United States)


    The Twenty-third Annual Software Engineering Workshop (SEW) provided 20 presentations designed to further the goals of the Software Engineering Laboratory (SEL) of the NASA-GSFC. The presentations were selected on their creativity. The sessions which were held on 2-3 of December 1998, centered on the SEL, Experimentation, Inspections, Fault Prediction, Verification and Validation, and Embedded Systems and Safety-Critical Systems.

  10. NATO’s Relevance in the Twenty-First Century (United States)


    rules of engagement for force protection.19 NATO Foreign Ministers authorized the Supreme Allied Commander Europe (SACEUR) to begin the next stage of...the mission on 9 December 2004. The activation order for this next stage was given by SACEUR on 16 December 2004. It allowed the deployment of 300...Christopher Coker, Globalisation and Insecurity in the Twenty-first Century: NATO and the Management of Risk (The International Institute for Strategic

  11. Proceedings of the twenty-first LAMPF users group meeting

    Energy Technology Data Exchange (ETDEWEB)


    The Twenty-First Annual LAMPF Users Group Meeting was held November 9-10, 1987, at the Clinton P. Anderson Meson Physics Facility. The program included a number of invited talks on various aspects of nuclear and particle physics as well as status reports on LAMPF and discussions of upgrade options. The LAMPF working groups met and discussed plans for the secondary beam lines, experimental programs, and computing facilities.

  12. About capital in the twenty-first century



    In this article, I present three key facts about income and wealth inequality in the long run emerging from my book, Capital in the Twenty-First Century, and seek to sharpen and refocus the discussion about those trends. In particular, I clarify the role played by r > g in my analysis of wealth inequality. I also discuss some of the implications for optimal taxation, and the relation between capital-income ratios and capital shares.

  13. Technological sciences society of the twenty-first century

    Energy Technology Data Exchange (ETDEWEB)



    This book introduces information-oriented society of the twenty-first century connected to computer network for example memory of dream : F-ram, information-oriented society : New media, communications network for next generation ; ISDN on what is IDSN?, development of information service industry, from office automation to an intelligent building in the future, home shopping and home banking and rock that hinders information-oriented society.

  14. The November $J / \\Psi$ Revolution Twenty-Five Years Later

    CERN Document Server

    Khare, A


    Exactly twenty five years ago the world of high energy physics was set on fire by the discovery of a new particle with an unusually narrow width at 3095 MeV, known popularly as the $J/\\Psi$ revolution. This discovery was very decisive in our understanding as well as formulating the current picture regarding the basic constituents of nature. I look back at the discovery, pointing out how unexpected, dramatic and significant it was.

  15. Proceedings of the twenty-second LAMPF users groupd meeting

    Energy Technology Data Exchange (ETDEWEB)

    Marinuzzi, R.


    The Twenty-Second Annual LAMPF Users Group Meeting was held October 17--18, 1988, at the Clinton P. Anderson Meson Physics Facility. The program included a number of invited talks on various aspects of nuclear and particle physics as well as status reports on LAMPF and discussions of upgrade options. The LAMPF working groups met and discussed plans for the secondary beam lines, experimental programs, and computing facilities.

  16. Early twenty-first-century droughts during the warmest climate

    Directory of Open Access Journals (Sweden)

    Felix Kogan


    Full Text Available The first 13 years of the twenty-first century have begun with a series of widespread, long and intensive droughts around the world. Extreme and severe-to-extreme intensity droughts covered 2%–6% and 7%–16% of the world land, respectively, affecting environment, economies and humans. These droughts reduced agricultural production, leading to food shortages, human health deterioration, poverty, regional disturbances, population migration and death. This feature article is a travelogue of the twenty-first-century global and regional droughts during the warmest years of the past 100 years. These droughts were identified and monitored with the National Oceanic and Atmospheric Administration operational space technology, called vegetation health (VH, which has the longest period of observation and provides good data quality. The VH method was used for assessment of vegetation condition or health, including drought early detection and monitoring. The VH method is based on operational satellites data estimating both land surface greenness (NDVI and thermal conditions. The twenty-first-century droughts in the USA, Russia, Australia and Horn of Africa were intensive, long, covered large areas and caused huge losses in agricultural production, which affected food security and led to food riots in some countries. This research also investigates drought dynamics presenting no definite conclusion about drought intensification or/and expansion during the time of the warmest globe.

  17. Soil Stratigraphy from Three Pleistocene Archaeological Sites of the Middle Ter River Valley, Catalonia, Spain

    Directory of Open Access Journals (Sweden)

    Sayantani NEOGI


    Full Text Available This dissertation summarizes the stratigraphic description of three Pleistocene archaeological sites inthe middle Ter river valley. A long history of archaeological research in this region suggests thepossibility of developing contextual studies. This work is basically an investigation of two soilformation processes from the deep soil horizons of the Mediterranean region: clay illuviation andcarbonatation. This approach has been developed by soil micromorphology, a technique well suitedfor this type of record, supplemented by fundamental field descriptions and basic cartography of the geomorphological terraces of the middle Ter river valley. The soil stratigraphy of archaeological sites and Pleistocene landscapes opens the opportunity to investigate a complex subject of study. The soils and paleosols are a source of information for palaeoecology and human occupations. It has been attempted here only to lay the groundwork for the interpretation of genetic factors pointing to the classification of soils.

  18. Consideration upon the River system in the north of the Suceava tableland

    Directory of Open Access Journals (Sweden)



    Full Text Available The paleoevolution of the river system in the Moldavian Tableland has undergone at a theoretical level two successive hypothetical directions. The former direction, formulated in the first half of the XXth century, alleges the existence of a river system, with a transverse character, that prolonged to the east the Carpathian river systems. Specialists of this theory, Tufescu V. (1932, M. David (1933, quoted by V. Bacauanu - 1973 and Gheorghe Nastase (1946, quoted by V. Bacauanu - 1973 based their design on the presence of horizons of gravels with Carpathian elements on some interfluves to the east of the Siret valley, and the existence of some saddles, Loznica, Bucecea and Ruginoasa, located on the left side of the same river. The latter direction, diametrically opposite, supports the idea of evolution of the river system consecutively with the Sarmato-Pliocene Sea pulling back to the south. The hypothesis is supported and substantiated by I. Sîrcu (1955, C. Martiniuc and V. Bacauanu (1960, V. Bacauanu (1968, 1973. In this context it is considered that the Prut and Siret rivers carved the oldest valleys in the tableland. The authors explain the erosional genesis of the saddles arguing their inability to create transversal rivers on the basis of continuity upstream and downstream the saddles of terrace levels with relatively high altitudes, which proves the flow continuity on consequent valleys. The research carried out along the Suceava river valley and the immediate interstream area in order to create a scenario of the valley paleoevolution highlighted the presence of crystalline lithotopes in the petrographic structure of the accumulation deposits. The presence of such petrographic elements contradicts the present-day alluvia sources of the rivers that could have transported them:  Suceava or its tributaries Solonet, Ilisasca, Scheia. The rivers spring either from the Carpathian flysch or from the former area of platform sedimentation. We

  19. Geological characterization of agricultural terraces as a tool for the territorial safeguard and for the valorization of "Terroir" (United States)

    Brancucci, Gerardo; Brancucci, Michele; Marescotti, Pietro; Poggi, Eugenio; Solimano, Monica; Vegnuti, Roberto; Giostrella, Paola; Tarolli, Paolo


    The progressive abandonment of the terraced areas of Liguria (NW Italy) is determining an inexorable land degradation, which causes, among other things, the erosive processes and the slope failure. Several studies highlighted the need of strategies for the recovery of abandoned agricultural lands by encouraging the productive reuse. Nevertheless, it is well known that agricultural activities in rural areas with steep slopes are strongly penalized by the high production costs determined by the adverse geomorphological conditions. For these reasons, one of the possible solutions is to encourage the production of high-quality agricultural crops, and to promote the uniqueness of the products. The uniqueness of the local products can be promoted not only by means of marketing strategy, mostly based on historical and traditional aspects of the productions, but also by correlating the product with the geological features (e.g., lithology, mineralogy and geochemistry) of the agricultural soils and parental rocks. These features are typically peculiar of a geographic area and thus strictly correlated with the site of production. This approach, together with the biological characterization of the crop, can link the cultivar to the geographical area of production thus evidencing peculiarities that are inimitable elsewhere. With this work we present the experimental results of investigations performed on several types of agricultural products (grapes and wines, olives and olive oils, apples) as well as on wild mushroom of the Boletus family. The analyses have been carried out either in laboratory and by means of field portable instruments (FP-EDXRF and FP-FTIR) which permitted a large number of in situ analyses, in a cost efficient and timely manner, thus allowing the realization of high spatial resolution compositional maps. This analytical approach also resulted particularly effective to improve the information obtained by traditional pedological and agronomical

  20. Water resources of Red River Parish, Louisiana (United States)

    Newcome, Roy; Page, Leland Vernon


    Red River Parish is on the eastern flank of the Sabine uplift in northwestern Louisiana. The 'area is underlain by lignitic clay and sand of Paleocene and Eocene age which dip to the east at the rate of about 30 feet per mile. The Red River is entrenched in these rocks in the western part of the parish. Alternating valley filling and erosion during the Quaternary period have resulted in the present lowland with flanking terraces. In the flood-plain area moderate to large quantities of very hard, iron-bearing water, suitable for irrigation, are available to wells in the alluvial sand and gravel of Quaternary age. The aquifer ranges in thickness from 20 to slightly more than 100 feet. It is recharged by downward seepage of rainfall through overlying clay and silt, by inflow from older sands adjacent to and beneath the entrenched valley, and by infiltration from the streams where the water table is below stream level during flood stages or as a result of pumping. Water levels are highest in the middle of the valley. Ground water moves mainly toward the Red River on the east and Bayou Pierre on the west, but small amounts move down the valley. Computations based on water-level and aquifer-test data indicate that the Quaternary alluvium contains more than 330 billion gallons of ground water in storage and that the maximum discharge of ground water to the streams is slightly more than 30 mgd (million gallons per day). At times of high river stage, surface water flows into the aquifer at a rate that depends in part upon the height and duration of the river stage. Moderate supplies of soft, iron-bearing water may be obtained from dissected Pleistocene terrace deposits that flank the flood plains of the Red River and Black Lake Bayou. However, the quantity of water that can be pumped from these deposits varies widely from place to place because of differences in the areal extent and saturated thickness of the segments of the deposits; this extent and thickness are governed

  1. Source and fate of inorganic solutes in the Gibbon River, Yellowstone National Park, Wyoming, USA. II. Trace element chemistry (United States)

    McCleskey, R. Blaine; Nordstrom, D. Kirk; Susong, David D.; Ball, James W.; Taylor, Howard E.


    The Gibbon River in Yellowstone National Park receives inflows from several geothermal areas, and consequently the concentrations of many trace elements are elevated compared to rivers in non-geothermal watersheds. Water samples and discharge measurements were obtained from the Gibbon River and its major tributaries near Norris Geyser Basin under the low-flow conditions of September 2006 allowing for the identification of solute sources and their downstream fate. Norris Geyser Basin, and in particular Tantalus Creek, is the largest source of many trace elements (Al, As, B, Ba, Br, Cs, Hg, Li, Sb, Tl, W, and REEs) to the Gibbon River. The Chocolate Pots area is a major source of Fe and Mn, and the lower Gibbon River near Terrace Spring is the major source of Be and Mo. Some of the elevated trace elements are aquatic health concerns (As, Sb, and Hg) and knowing their fate is important. Most solutes in the Gibbon River, including As and Sb, behave conservatively or are minimally attenuated over 29 km of fluvial transport. Some small attenuation of Al, Fe, Hg, and REEs occurs but primarily there is a transformation from the dissolved state to suspended particles, with most of these elements still being transported to the Madison River. Dissolved Hg and REEs loads decrease where the particulate Fe increases, suggesting sorption onto suspended particulate material. Attenuation from the water column is substantial for Mn, with little formation of Mn as suspended particulates.

  2. The role of river trajectories and channel recovery potential within sustainable river management: some case studies from southern Italy (United States)

    Rosskopf, Carmen Maria; Scorpio, Vittoria; Patrizio Ciro Aucelli, Pietro


    Most of Italian and European rivers have undergone notable channel adjustments since the last 150-200 years. Major adjustments fall within the second half of the last century and consisted in overall channel narrowing and degradation, accompanied by important pattern changes. In the cases of the six investigated rivers located in southern Italy (namely Trigno, Biferno, Fortore, Volturno, Sinni and Crati), major adjustments occurred from the 1950s to the end of the 1990s. They consisted in channel narrowing up to 98%, bed level lowering from -2 to -10m and extensive changes from multi-thread to single thread pattern that led to the abandonment of extensive channel areas and consistent increase of floodplain and terraced areas. The integrated analysis of river trajectories and potential control factors, both of natural and anthropic origin, showed that human disturbances, especially gravel mining and river control works, are key driving factors of channel adjustments. Furthermore, the presence of major hydraulic structures along the rivers Biferno, Fortore, Sinni and Trigno significantly influenced the amounts of channel adjustments which are sharply higher within the reaches located downstream of such structures. Considering the last 15-20 years, most of the evolutionary trajectories of the investigated reaches highlight ongoing channel stabilization or even some appreciable channel recovery. Particularly, channel widening had occurred in those reaches that are not under the direct influence of major hydraulic structures (check-dams and dams) and in which in-channel interventions had pratically ceased and woody riparian vegetation developed only in a discontinuous manner. Conversely, the reaches that are located immediately downstream of major hydraulic structures, in which control works are placed very close to the actual riverbanks and/or a continuous riparian forest has developed, appear stable, only locally affected by very slight widening, or even affected by

  3. Twenty-first workshop on geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)



    PREFACE The Twenty-First Workshop on Geothermal Reservoir Engineering was held at the Holiday Inn, Palo Alto on January 22-24, 1996. There were one-hundred fifty-five registered participants. Participants came from twenty foreign countries: Argentina, Austria, Canada, Costa Rica, El Salvador, France, Iceland, Indonesia, Italy, Japan, Mexico, The Netherlands, New Zealand, Nicaragua, the Philippines, Romania, Russia, Switzerland, Turkey and the UK. The performance of many geothermal reservoirs outside the United States was described in several of the papers. Professor Roland N. Horne opened the meeting and welcomed visitors. The key note speaker was Marshall Reed, who gave a brief overview of the Department of Energy's current plan. Sixty-six papers were presented in the technical sessions of the workshop. Technical papers were organized into twenty sessions concerning: reservoir assessment, modeling, geology/geochemistry, fracture modeling hot dry rock, geoscience, low enthalpy, injection, well testing, drilling, adsorption and stimulation. Session chairmen were major contributors to the workshop, and we thank: Ben Barker, Bobbie Bishop-Gollan, Tom Box, Jim Combs, John Counsil, Sabodh Garg, Malcolm Grant, Marcel0 Lippmann, Jim Lovekin, John Pritchett, Marshall Reed, Joel Renner, Subir Sanyal, Mike Shook, Alfred Truesdell and Ken Williamson. Jim Lovekin gave the post-dinner speech at the banquet and highlighted the exciting developments in the geothermal field which are taking place worldwide. The Workshop was organized by the Stanford Geothermal Program faculty, staff, and graduate students. We wish to thank our students who operated the audiovisual equipment. Shaun D. Fitzgerald Program Manager.

  4. Twenty-first-century medical microbiology services in the UK. (United States)

    Duerden, Brian


    With infection once again a high priority for the UK National Health Service (NHS), the medical microbiology and infection-control services require increased technology resources and more multidisciplinary staff. Clinical care and health protection need a coordinated network of microbiology services working to consistent standards, provided locally by NHS Trusts and supported by the regional expertise and national reference laboratories of the new Health Protection Agency. Here, I outline my thoughts on the need for these new resources and the ways in which clinical microbiology services in the UK can best meet the demands of the twenty-first century.

  5. Twenty years of energy policy: What should we have learned?

    Energy Technology Data Exchange (ETDEWEB)

    Greene, D.L. [Oak Ridge National Lab., TN (United States). Center for Transportation Analysis


    This report examines the past twenty years of energy market events and energy policies to determine what may be useful for the future. The author focuses on two important lessons that should have been learned but which the author feels have been seriously misunderstood. The first is that oil price shocks were a very big and very real problem for oil importing countries, a problem the has not gone away. The second is that automobile fuel economy regulation has worked and worked effectively to reduce oil consumption and the externalities associated with it, and can still work effectively in the future.

  6. Accelerators for the twenty-first century a review

    CERN Document Server

    Wilson, Edmund J N


    The development of the synchrotron, and later the storage ring, was based upon the electrical technology at the turn of this century, aided by the microwave radar techniques of World War II. This method of acceleration seems to have reached its limit. Even superconductivity is not likely to lead to devices that will satisfy physics needs into the twenty-first century. Unless a new principle for accelerating elementary particles is discovered soon, it is difficult to imagine that high-energy physics will continue to reach out to higher energies and luminosities.

  7. Earth observations in the twenty-first century (United States)

    Geller, M. A.


    Some of the achievements of earth observations from past space missions are described. Also discussed are the achievements to be anticipated from currently approved and planned earth observation missions. In looking forward to what the objectives of earth observations from space are expected to be in the future, together with what technology is expected to enable, what the earth observing program will look like during the first part of the twenty-first century is discussed. It is concluded that a key part of this program will be long-term observations holistically viewing the earth system.

  8. Vinte anos de efeito SERS Twenty years of SERS

    Directory of Open Access Journals (Sweden)

    Dalva L. A. de Faria


    Full Text Available The Surface Enhanced Raman Scattering (SERS effect was observed for the first time in 1974, but it was only considered a new effect three years later, hence, nearly twenty years ago. Since its discovery, a significant amount of investigations have been performed aiming at to clarify the nature of the observed enhancement, to improve the surface stability and to establish applications which nowadays range from the study of biomolecules to catalysis. Some of the more relevant aspects of this effect which have been examined across the last two decades are summarized in this paper which presents the introductory aspects of SERS alongside with several of its applications.

  9. Palaeoclimate reconstructions from lacustrine terraces and lake-balance modeling in the southern central Andes: New insights from Salar de Pocitos (Salta Province, Argentina) (United States)

    Bekeschus, Benjamin; Bookhagen, Bodo; Strecker, Manfred R.; Freymark, Jessica; Eckelmann, Felix; Alonso, Ricardo


    The arid Puna Plateau in the southern central Andes of NW-Argentina constitutes the southern part of Earth's second largest orogenic plateau. Numerous internally drained basins are restricted by ranges that peak 5-6 km above sea level, creating a compressional basin and range morphology. The conspiring effects of this structurally controlled topography and the high degree of aridity have resulted in low stream power of the fluvial network and internally drained basins. A steep rainfall gradient exists across this area ranging from a humid Andean foreland (>1m/yr annual rainfall) to progressively drier areas westwards. At the present-day, the interior of the plateau is widely characterized by annual rainfall and high evaporation rates. Thus continuous lacustrine archives are limited and sediments are dominated by evaporites. Several closed basins contain vestiges of moister conditions from past pluvial periods. For example, the staircase morphology of lacustrine shorelines and abrasion platforms in the distal sectors of alluvial fans and pediments at Salar de Pocitos (24.5°S, 67°W, 3650 m asl) records repeated former lake highstands. This intermontane basin has existed since the late Tertiary, constituting a 435 km² salt flat in the region of Salta, NW Argentina. Comparison with palaeoclimate records from the neighboring Salar de Atacama suggests that the terrace systems at Salar de Pocitos were formed during the Late Pleistocene and early Holocene. Here we report on our preliminary results of the extent of several terrace generations in this region. We mapped terraces in the field and on satellite images and determined their elevations during a high-resolution DGPS field survey. Our analysis reveals 3-4 distinct terrace levels associated with individual lake-level highstands. However, basin-wide correlation is difficult due to ongoing tectonism and differential tilting of the basin. The highest lake terrace, ca. 25 m above modern base level, locally comprises a

  10. Strategies for Teaching Maritime Archaeology in the Twenty First Century (United States)

    Staniforth, Mark


    Maritime archaeology is a multi-faceted discipline that requires both theoretical learning and practical skills training. In the past most universities have approached the teaching of maritime archaeology as a full-time on-campus activity designed for ‘traditional’ graduate students; primarily those in their early twenties who have recently come from full-time undergraduate study and who are able to study on-campus. The needs of mature-age and other students who work and live in different places (or countries) and therefore cannot attend lectures on a regular basis (or at all) have largely been ignored. This paper provides a case study in the teaching of maritime archaeology from Australia that, in addition to ‘traditional’ on-campus teaching, includes four main components: (1) learning field methods through field schools; (2) skills training through the AIMA/NAS avocational training program; (3) distance learning topics available through CD-ROM and using the Internet; and (4) practicums, internships and fellowships. The author argues that programs to teach maritime archaeology in the twenty first century need to be flexible and to address the diverse needs of students who do not fit the ‘traditional’ model. This involves collaborative partnerships with other universities as well as government underwater cultural heritage management agencies and museums, primarily through field schools, practicums and internships.

  11. Projected deglaciation of western Canada in the twenty-first century (United States)

    Clarke, Garry K. C.; Jarosch, Alexander H.; Anslow, Faron S.; Radić, Valentina; Menounos, Brian


    Retreat of mountain glaciers is a significant contributor to sea-level rise and a potential threat to human populations through impacts on water availability and regional hydrology. Like most of Earth’s mountain glaciers, those in western North America are experiencing rapid mass loss. Projections of future large-scale mass change are based on surface mass balance models that are open to criticism, because they ignore or greatly simplify glacier physics. Here we use a high-resolution regional glaciation model, developed by coupling physics-based ice dynamics with a surface mass balance model, to project the fate of glaciers in western Canada. We use twenty-first-century climate scenarios from an ensemble of global climate models in our simulations; the results indicate that by 2100, the volume of glacier ice in western Canada will shrink by 70 +/- 10% relative to 2005. According to our simulations, few glaciers will remain in the Interior and Rockies regions, but maritime glaciers, in particular those in northwestern British Columbia, will survive in a diminished state. We project the maximum rate of ice volume loss, corresponding to peak input of deglacial meltwater to streams and rivers, to occur around 2020-2040. Potential implications include impacts on aquatic ecosystems, agriculture, forestry, alpine tourism and water quality.

  12. Santiago: Modernisation, segregation and urban identities in the twenty first century

    Directory of Open Access Journals (Sweden)

    Francisca Márquez


    Full Text Available This paper discusses research carried out in Santiago, Chile, and addresses the origin and construction of urban identities in this segregated city of the twenty first century. Based on sociological and ethnographic evidence, urban identity building processes are analysed by observing the occupation, use and appropriation of territory. The hypothesis is that, despite evidence of segregation, modernisation and globalisation, urban people reinvent lifestyles within their territories in order to harmonise their bonds of affection and belonging by using distinguishing markings or “brands” and by adopting typical everyday habits. The modern, segregated and global city is filled with “islands” that convey imagery and desires for a friendlier urban life. This paper analyses areas with community identities, neo community identities and border identities. It suggests that, just as community identities shelter nostalgia for a lost community (by finding refuge or reinventing ways to make the fringes of the city habitable in the background or on the “other side��� of the Mapocho River and very near the historical centre of the city, border identities have also arisen and persisted; these subvert the orderly and hegemonic city, resulting in a diverse, heterogeneous and multicultural lifestyle. The result is a synthesis and an urban lifestyle.

  13. Insights on the Quaternary Tectonic Evolution of the SE Indonesia Arc-Continent Collision from the Study of Uplifted Coral Terraces on Sumba Island. (United States)

    Leclerc, F.; Rigaud, S.; Chiang, H. W.; Djamil, Y. S.; Herdiyanti, T.; Johnny, J.; Ildefonso, S.; Meilano, I.; Bijaksana, S.; Abidin, H. Z.; Tapponnier, P.; Wang, X.


    Sumba Island is uniquely positioned within the Sunda-Banda forearc, at the transition between oceanic subduction and arc-continent collision. There, the convergence between the Sunda and Australian plates is accommodated along at least three major structures: the megathrust, the Savu backthrust located south of Sumba and the Flores backthrust located north of the volcanic arc. The incipient collision in the vicinity of Sumba is responsible for coastal vertical movements. Quaternary reefal deposits form spectacular uplifted flights of terraces, which directly overlie Mid Miocene - Early Pliocene deep carbonate and volcaniclastic rocks at elevations exceeding 500m. Although aerial fossil reefs extensively rim the northern and eastern coasts of Sumba, studies have been limited to Cape Laundi where an uplift rate of 0.2-0.5 m/kyr is estimated for the last 400 kyr, partly on the basis of alpha-spectrometric U/Th dating. At the island scale, the relief morphology and the hydrographic network point to a N-S asymmetry, indicating a general tilt toward the north. A subducting seafloor asperity and south-dipping normal faults have been postulated to generate this asymmetry. However as the pattern and kinematics of the deformation remain partially determined, structures and processes capable of driving such deformation and accommodating the nascent collision may be undisclosed. New topographic data coupled with field observations and coral mass-spectrometric U/Th dating allow investigating the morphology, stratigraphy and age of the fossil reef terraces at the island scale. Tectonic structures disrupting the topography are identified and their activities are relatively dated with respect to fossil reef terraces. The deformation pattern of Sumba is characterized, especially in Cape Laundi where the uplift rate is re-evaluated. Through a multi-disciplinary study, we intend to reconstruct the tectonic evolution of Sumba island and, at a larger scale, of the collision in SE

  14. Soil depth map definition on a terraced slope for a following distributed, high resolution, numerical modelling analysis (United States)

    Camera, C.; Apuani, T.; Mele, M.; Kuriakose, S. L.; Giudici, M.


    The soil thickness represents a key data for every environmental analysis involving soil, but its determination is not always simple. In this particular case, the study area is represented by a small terraced slope (0.6 km2) of Valtellina (Northern Italy), and the soil depth map is necessary for a coupled hydrogeological-stability analysis in a raster environment. During this work geometrical/morphological and geostatistical interpolation techniques were tested to obtain a satisfying soil depth map. At the end, the final product has been validated with geo-electrical resistivity inverse models. In this particular context, the presence of dry-stone retaining walls is of primary importance, since they have an influence on the morphology of the entire area as well as on the physical processes of water infiltration and slope stability. In order to consider the dry-stone walls in the analysis, it is necessary to have base maps with an adequate resolution (cells 1 m x 1 m). Assuming that the walls might be founded on bedrock or in its proximity, it was decided to use the heights of walls and the distribution of rock outcrops as soil depth input data. It was impossible to obtain direct measures with the knocking pole method, being pebbles frequently presents in the backfill soil . Except zero depth values, 682 measures were performed. The initial data set was divided into two subsets in order to use one as training points (76 % of the total) and the second as test points (24 %). Various techniques were tested, from linear multiple regressions with environmental predictors, to ordinary kriging, regression kriging with the same environmental variables, and Gaussian stochastic simulations. At the end, the best result was obtained with co-kriging, using a soil depth class map drawn from the field measures as co-variable. The result is a little bit guided but it was the only solution to obtain a map that partially takes into account the morphology of the slope. To verify the

  15. Simulation of the fate of Boscalid and its transformation product 4-Chlorobenzoic acid in a vineyard-terraces catchment (United States)

    Vollert, Dieter; Gassmann, Matthias; Olsson, Oliver; Kümmerer, Klaus


    In the viniculture fungicides are commonly applied foliar on the plant surface, resulting in high concentrations in runoff water. The fungicide Boscalid occurred frequently and in high concentrations in runoff water in the Loechernbach catchment, a 180 ha vineyard catchment in south-west Germany, during rainfall-runoff events in 2016. The catchment is characterized by a typical terraces structure and the connection of a dense road network. The washing off from drift-depositions on the streets is expected to be a major pathway for pesticides. The main objective of this study was the provision of a catchment model to simulate the transport and transformation processes of Boscalid. Based on this model, source areas of Boscalid residue pollution and its export pathways will be identified and provide urgently needed information for the development of water pollution control strategies. The distributed, process-based, reactive transport catchment model ZIN-AgriTra was used for the evaluation of the pesticide mobilization and the export processes. The hydrological model was successfully calibrated for a 6-month high-resolution time series of discharge data. Pesticide modelling was calibrated for single rainfall events after Boscalid application. Additionally, the transformation product 4-Chlorobenzoic acid has been simulated using literature substance parameters, in order to gain information about anticipated environmental concentrations. The pathways for the discharge of Boscalid were characterized and the streets were confirmed as major pathway for the pesticide discharge in the catchment. The main Boscalid loss occured during the first flush after a storm event containing concentrations up to 10 µg/l. The results show that storage on surfaces without sorption contributes significantly to the export of pesticides through the first flush. Therefore, the mobilization process affects a combination of both sorptive (e.g. at the soil) and non-sorptive (e.g. on the surface

  16. How to analyse the typological features of stone terrace walls. A methodology applied to the rural landscape of the Tuscan Region (Central Italy) (United States)

    Agnoletti, Mauro; Conti, Leonardo; Frezza, Lorenza; Santoro, Antonio


    Terraced systems currently represent an indubitable added value for Tuscany, as for other regions. This value goes beyond their original function of hosting new areas for cultivation. Indeed, the hydrological functions performed by such systems within the historic and modern agricultural matrix, including control of erosion, stabilisation of the slopes, prolongation of run-off times and the possible reduction of the volumes of surface runoff, are well-known. In addition they also play a strategic role in the conservation of biodiversity and in maintaining local identity value. These systems are evidence of the laborious knowledge built up by many generations of farmers in making the most of the territorial resources in terms of quality production through agronomic operations for the management of the crops. Within the framework of policies for the conservation and valorisation of the rural landscape, this recognised economic, environmental and historic-cultural value has engendered a growing awareness and sensitivity towards the safeguarding of such structural characteristics. Indeed, at national level the terraced agricultural systems come within the scope of actions scheduled in the National Strategic Plan for Rural Development 2007-2013, and the Cross-Compliance Decree envisages that they be maintained through the granting of economic aid as laid down in the Regional Development Plans, to be pursued through appropriate agronomic and environmental conditions in adherence to the obligatory management criteria for the protection of the soil. 18 sample areas, previously selected on the basis of the terracing intensity index (> 400 m/ha), were subjected to on-site surveys to determine the geo-typological features through the identification and measurement of the main technical-construction parameters of the dry stone walls. In view of the complexity of carrying out a census of the entire regional territory, it was essential to restrict the analysis to a limited

  17. Reduced step edges on rutile TiO (110) as competing defects to oxygen vacancies on the terraces and reactive sites for ethanol dissociation

    DEFF Research Database (Denmark)

    Martinez, U.; Hansen, Jonas Ørbæk; Salazar, Estephania Lira


    microscopy studies, we here present experimental evidence for the existence of O vacancies along the ⟨11̅ 1⟩R step edges (OS vac.’s) on rutile TiO2(110). Both the distribution of bridging O vacancies on the terraces and temperature-programed reaction experiments of ethanol-covered TiO2(110) point...... to the existence of the OS vac.’s. Based on experiments and density functional theory calculations, we show that OS vac.’s are reactive sites for ethanol dissociation via O-H bond scission. Implications of these findings are discussed...

  18. Uncertainties in sea level projections on twenty-year timescales (United States)

    Vinogradova, Nadya; Davis, James; Landerer, Felix; Little, Chris


    Regional decadal changes in sea level are governed by various processes, including ocean dynamics, gravitational and solid earth responses, mass loss of continental ice, and other local coastal processes. In order to improve predictions and physical attribution in decadal sea level trends, the uncertainties of each processes must be reflected in the sea level calculations. Here we explore uncertainties in predictions of the decadal and bi-decadal changes in regional sea level induced by the changes in ocean dynamics and associated redistribution of heat and freshwater (often referred to as dynamic sea level). Such predictions are typically based on the solutions from coupled atmospheric and oceanic general circulation models, including a suite of climate models participating in phase 5 of the Coupled Model Intercompasion Project (CMIP5). Designed to simulate long-term ocean variability in response to warming climate due to increasing green-house gas concentration ("forced" response), CMIP5 are deficient in simulating variability at shorter time scales. In contrast, global observations of sea level are available during a relatively short time span (e.g., twenty-year altimetry records), and are dominated by an "unforced" variability that occurs freely (internally) within the climate system. This makes it challenging to examine how well observations compare with model simulations. Therefore, here we focus on patterns and spatial characteristics of projected twenty-year trends in dynamic sea level. Based on the ensemble of CMIP5 models, each comprising a 240-year run, we compute an envelope of twenty-year rates, and analyze the spread and spatial relationship among predicted rates. An ensemble root-mean-square average exhibits large-scale spatial patterns, with the largest uncertainties found over mid and high latitudes that could be attributed to the changes in wind patterns and buoyancy forcing. To understand and parameterize spatial characteristics of the

  19. Tracing recent environmental changes and pedogenesis using geochemistry and micromorphology of alluvial soils, Sabie-Sand River Basin, South Africa (United States)

    Eze, Peter N.; Knight, Jasper; Evans, Mary


    Three pedons on the alluvial terraces of the Sabie-Sand River Basin within Kruger National Park, South Africa, were studied to improve our understanding of recent environmental changes, and assess degree of chemical weathering and pedogenesis in the area using geochemical and micromorphology proxies. Particle-size distributions were obtained using Malvern Mastersizer; soil geochemistry was determined by XRF and thin sections by routine laboratory procedures. The soils are predominantly sandy (> 94% sand in all samples). The mean phi-values of the soils had little variation suggesting that reworking of sediments upwards in individual profiles produced a more uniform pedogenesis rather than coming from different physical sources. Calcification is the dominant pedogenic process in these alluvial soils. The Chemical Index of Alteration (CIA) proved a more suitable index than Chemical Index of Weathering (CIW) for evaluating weathering in the terraces. The micromass and b-fabrics are mostly granostriated and partly brown mosaic speckled. MISECA values for the degree of soil development range from 4 to 9, which mean weakly to moderately-developed soils. Coarse secondary calcite nodules and coatings are responsible for cementation as observed in pedon 2, which suggests calcium carbonate precipitation from periodical flooding and evaporating groundwater events. The features and diagnostic properties of the soils on the alluvial terraces along the Sabie-Sand River provide evidence for land surface impacts of recent environmental changes in this internationally important conservation area. Precise dating of calcium carbonate precipitates is, however, needed to put the observed evidence into a wider geochronological perspective.

  20. River Morphology and River Channel Changes

    Institute of Scientific and Technical Information of China (English)

    CHANG Howard H


    River morphology has been a subject of great challenge to scientists and engineers who recognize that any effort with regard to river engineering must be based on a proper understanding of the morphological features involved and the responses to the imposed changes. In this paper,an overview of river morphology is presented from the geomorphic viewpoint. Included in the scope are the regime concept, river channel classification, thresholds in river morphology, and geomor-phic analysis of river