Channel and reservoir sedimentation, Ha Tsiu catchment, Maseru in Sediment sources, sediment residence time and sediment transfer-Case studies of soil erosion in the Lesotho lowlands.
Bassin-versant ; Erosion des sols ; Géographie de l'Afrique ; Géomorphodynamique ; Lesotho ; Maseru ; Sédimentation
Rates of channel sedimentation| rates of reservoir siltation| influence of vegetation, soil, land use and slope on the rates of sediment processes.
Rate of sedimentation in Lake Kinneret, Israel : spatial and temporal variations
Biogenic process ; Israel ; Lacustrine sedimentation ; Lake ; Seasonal variation ; Sedimentationrate ; Spatial variation ; Stream ; Suspended load
Action biogène ; Charge en suspension ; Cours d'eau ; Israël ; Lac ; Sédimentation lacustre ; Taux de sédimentation ; Variation saisonnière ; Variation spatiale
The aim of this study is to determine the seasonal and spatial patterns of sedimentationrates in Lake Kinneret. The method used in this study minimized the problem of sediment resuspension from the lake bottom, by locating the traps above lake
bottom. The rate of sedimentation near the Jordan's inflow is highly correlated to flow discharge in the river, while in the centre of the lake the seasonal sedimentation pattern is mainly correlated to the bloom period of Peridinium gatunense.
Modern sediment yield compared to geologic rates of sediment production in a semi-arid basin, New Mexico : assessing the human impact
Arid area ; Erosion rate ; Gully erosion ; Human impact ; Isotope analysis ; New Mexico ; Pastureland ; Sediment budget ; Semi-arid area ; Soil erosion ; United States of America ; Watershed
In the semi-arid Arroyo Chavez basin, the AA. compare modern short-term sediment yields measured using sediment traps and dams to geologic rates of sediment production estimated using cosmogenic nuclides. Contrasting modern, short-term rates
of sediment yield with long-term geologic or natural rates of sediment production allows assessment of human influences on erosion rates. At Arroyo Chavez, the AA. conclude that grazing is the likely cause for higher sediment yields on the alluvial valley
Using Be 10 and Al 26 to determine sediment generation rates and identify sediment source areas in an arid region drainage basin
Arid area ; Arizona ; Grain size distribution ; Isotope dating ; Model ; Sediment budget ; Sediment transport ; United States of America ; Watershed ; Weathering
In this work, the AA. apply the techniques developed for determining basin-wide sediment generation rates in small basins to both the entire Yuma Wash drainage and to smaller sub-basins of the Wash. Tracing nuclide concentrations in sediment along
the length of Yuma Wash, the AA. identify significant sediment source areas. Nuclide concentrations in upland basins represent the production rate of sediment from the weathering of bedrock (sediment generation). Nuclide concentrations in main stem samples
reflect both upland sediment generation and the long-term effects of sediment storage and reworking.
Rates and patterns of contemporary floodplain sedimentation : a case study of the River Culm, Devon, UK
A variety of methods have been used to document contemporary rates of overbank sedimentation along an 11 km reach of the floodplain of the River Culm. These have included measurements of the conveyance loss of suspended sediment between upstream
and downstream measuring stations, the use of sediment traps, and the application of caesium-137 measurements to estimate the rate of accumulation of fine sediment over the past 30 years.
. This model is designed for interpreting isotope abundance in sediment. The AA. suggest that measured isotope abundances may reflect spatially averaged rates of erosion if a basin is in isotopic steady state and if sampled sediments are well mixed.
This paper proposes, as a testable hypothesis, a basin-scale approach for interpreting the abundance of in situ produced cosmogenic isotopes, an approach which considers explicitly both the isotope and sediment flux through a drainage basin
Sediment transport rate-based model for rainfall-induced soil erosion
Experimentation ; Mathematical model ; Model ; Overland flow ; Precipitation ; Rainfall simulation ; Sediment transport ; Soil erosion ; Water erosion
A one-dimensional mathematical model, termed sediment transport rate-based model, is developed for determining rainfall-induced soil erosion and sediment transport. A series of soil flume experiments under simulated rainfall were conducted
to simulate the overland flow and sediment transport and to test the sediment transport rate-based model. The numerically simulated hydrographs, sediment transport rate and concentration distributions are in good agreement with those measured in laboratory
experiments, demonstrating the efficacy of the transport rate-based model.
Dynamics of soil erosion rates and controlling factors in the Northern Ethiopian Highlands - towards a sediment budget
Agricultural practice ; Erosion control ; Erosion rate ; Ethiopia ; Gully erosion ; Human impact ; Mountain ; Sediment budget ; Soil erosion ; Water erosion ; Watershed
This paper analyses the factors that control rates and extent of soil erosion processes in the May Zegzeg catchment near Hagere Selam in the Tigray Highlands. Soil loss rates due to various erosion processes, as well as sediment yield rates
and rates of sediment deposition within the catchment (essentially induced by recent soil conservation activities), were measured using a range of geomorphological methods. Soil loss rates by water (gully erosion) are important and also tillage erosion
Rates of overbank sedimentation on the floodplains of British lowland rivers documented using fallout 137Cs
Agricultural land use ; England ; Floodplain ; Fluvial processes ; Geochemistry ; Isotope ; Land use ; Sedimentation ; Sedimentationrate ; Tracer ; United Kingdom ; Watershed
Bassin-versant ; England ; Fluviatile ; Géochimie ; Isotope ; Plaine d'inondation ; Royaume-Uni ; Sédimentation ; Taux de sédimentation ; Traceur ; Utilisation agricole du sol ; Utilisation du sol
in the sediment profiles to obtain estimates of contemporary overbank sediment accumulation rates at the sampling locations. The 137Cs concentrations associated with the individual sediment cores were also compared and interpreted in terms of the sediment sources
Bomb-derived fallout 137Cs has been used as an environmental tracer. This study presents the 137Cs profiles for sediment cores collected from the floodplains of 12 lowland rivers in Britain and attempt to use the depths of the 1963 137Cs peak
and the sediment transport and deposition processes involved.
Tie channel sedimentationrates, oxbow formation age and channel migration rate from optically stimulated luminescence (OSL) analysis of floodplain deposits
Quantifying rates and timescales of geomorphic processes : part 2. Special issue
Alaska ; Dating ; Floodplain ; Fluvial processes ; Meander ; Mississippi ; Papua New Guinea ; Sedimentation ; Thermoluminescence ; United States of America
and allow the exchange of water and suspended sediment between the two. In all 3 river systems, OSL dating allowed the determination of vertical accretion rates, tie channel advancement rates, and oxbow lake ages.
The dated sediments were collected from the banks of tie channels along the Lower Mississippi River, the Fly River in Papua New Guinea, and Birch Creek along the Yukon River in Alaska. Tie channels connect the oxbow lakes to the main stem river
Soil erosion in different Lesotho environments-Rate and sediment sources in Sediment sources, sediment residence time and sediment transfer-Case studies of soil erosion in the Lesotho lowlands.
Inventory of sediment sources and possible storage areas and study of reservoir sediments, in three catchments in the lowland area of western Lesotho.
Use of floodplain sediment cores to investigate recent historical changes in overbank sedimentationrates and sediment sources in the catchment of the River Ouse, Yorkshire, UK
Bassin-versant ; Bilan sédimentaire ; Carottage ; Charge en suspension ; England ; Géochimie ; Plaine d'inondation ; Royaume-Uni ; Sédimentation ; Sédimentologie ; Traceur ; Utilisation du sol ; Yorkshire
Core sampling ; England ; Floodplain ; Geochemistry ; Land use ; Sediment budget ; Sedimentation ; Sedimentology ; Suspended load ; Tracer ; United Kingdom ; Watershed ; Yorkshire
This paper reports the use of sediment cores collected from river floodplains to provide information on changing suspended sediment sources and sedimentationrates at 7 sites within the non-tidal component of the catchment of the River Ouse, and one
of its main tributaries, the River Wharfe, in Yorkshire. The results enable estimates of contemporary suspended sediment fluxes and sources to be placed into a historical context and provide a means of considering the likely impact of potential future
Deep-sea sediments recovered from 6 sites visited during the International Artic Ocean Expedition of 1991 were examined to determine sedimentationrates in the eastern Artic Ocean basin. The AA. determine low-field magnetic susceptibility
in addition to anhysteretic and natural remanent magnetization and use these measurements in conjunction with carbonate stratigraphy (from one selected core), as well as radiocarbon dating of surface sediments (from two cores), to deduce sedimentationrates.
Varve studies at Hector Lake, Alberta, Canada, and the relationship between glacial activity and sedimentation
Action glaciaire ; Actuel ; Alberta ; Banff National Park ; Canada ; Géographie physique ; Géomorphodynamique ; Hector Lake ; Holocène ; Montagne ; Quaternaire zones moyennes ; Régime glaciaire ; Sédiment lacustre ; Sédimentation proglaciaire
A comparison of sedimentationrate records (Cs chronology) with recent regional glacial history indicates that high sedimentationrates of one to a few decades duration occur either during and immediately following periods of moraine deposition (ie
, maximum ice stands) or during periods of rapid ice recession. Comparison of sedimentary records with somewhat longer term glacial and vegetation records indicates that sedimentationrate variations of several centuries duration closely parallel changes
in upvalley ice extent. Over this time scale, high sedimentationrates occur during periods of relatively increased ice extent, low rates during periods of reduced ice extent.
Post-volcanic erosion rates of Shomyo Falls in Tateyama, Central Japan
Erosion rate ; Fluvial erosion ; Honshu ; Japan ; Pyroclastic ; Sediment transport ; Stream ; Volcanism ; Volcano
, not taken account of in the equation, significantly influence the recession rate. The AA. suggest that a factor in the rapid erosion of the waterfall is a large amount of transported sediment acting as abrasive material, which is supplied from high mountains
This study examines the rate of recession of Shomyo Falls, which consists of Pleistocene welded pyroclastic flows deposits in Toyama Prefecture. The discrepancy between the geology-based and equation-based recession rates indicates that some factors
This study compares depth- and volume-based estimates of sediment accumulation for well-dated vertical accretion sequences at Broomhaugh Island in the Tyne basin, northern England. High resolution dating control (based on heavy metal stratigraphy
and cartography) coupled with detailed reconstruction of channel geometry allows accumulation rates to be calculated for the last 300-400 years. The results show a marked disparity in the magnitude and pattern of vertical accretion rates between the 2 approaches.
Trends in Chesapeake Bay sedimentationrates during the late Holocene
The objectives of this study were : 1) to determine the extent to which sedimentationrates have changed over the lifetime of the estuary| 2) to determine whether infilling of the estuary and postglacial sea-level rise have been coupled