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.
Dating ; Holocene ; Isotope analysis ; Lacustrine sedimentation ; Paleogeography ; Paleomagnetism ; Quaternary ; Sediment transport ; United Kingdom ; Wales
Estimates of suspended sediment yield over the past 800 years have been derived from a whole-basin study of lake sediments in Llyn Geirionydd, North Wales. Magnetic and physical sediment properties were used to correlate a suite of cores to a master
chronology based on 210Pb and 14C dates. The sources of sediment within the catchment were identified by comparing the magnetic and heavy metal properties of sediments, soils, and stream sediments.
A design for a sediment flux sensor is provided for use in sedimentation studies in lacustrine and shallow marine environments. The sensor utilizes an optical system to measure sediment accumulation with a data logger. Unlike other passive
or mechanical sediment trapping systems, the sediment flux sensor records the time of deposition precisely and therefore is useful for investigating the linkages between external processes (hydrological) and sedimentation.
The fate of eroded soil: sediment sinks and sediment budgets of agrarian landscapes in southern Minnesota, 1851-1988
Flood ; Floodplain ; Minnesota ; Palaeosol ; Sediment budget ; Sediment transport ; Soil erosion ; United States ; Watershed
This paper examines the fate of eroded soil by tracing the distribution of eroded sediment and constructing the sediment budgets of three medium-size drainage basins in southern Minnesota. This research attempts to improve our understanding
of sediment sinks and flux, of the dynamic resources of drainage basins, and of what has been called the sediment delivery problem.
Rate of sedimentation in Lake Kinneret, Israel : spatial and temporal variations
Action biogène ; Charge en suspension ; Cours d'eau ; Israël ; Lac ; Sédimentation lacustre ; Taux de sédimentation ; Variation saisonnière ; Variation spatiale
Biogenic process ; Israel ; Lacustrine sedimentation ; Lake ; Seasonal variation ; Sedimentation rate ; Spatial variation ; Stream ; Suspended load
The aim of this study is to determine the seasonal and spatial patterns of sedimentation rates 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.
Present and future conditions of reservoir sedimentation
Sedimentological studies in the Cachi reservoir, Costa Rica. Sediment inflow, reservoir sedimentation, and effects of flushing
Aménagement hydraulique ; Barrage-réservoir ; Bassin-versant ; Bilan sédimentaire ; Charge en suspension ; Costa Rica ; Hydrologie appliquée ; Sédimentation
Applied hydrology ; Catchment area;Watershed ; Costa Rica ; Dam ; Hydraulic works ; Sediment budget ; Sedimentation ; Suspended load
The AA. present sediment budgets for the reservoir during different periods, based upon different methods applied in their investigations. Basic information is presented for the budgets on sediment inflow, flow conditions within the reservoir
, sediment deposition in the reservoir, throughflow of suspended material and evacuation during flushing.
Understanding watershed suspended sediment transport
This paper synthesizes a variety of methods adopted in suspended sediment monitoring, estimation and modelling for understanding sediment transport processes and determining the suspended sediment load. Methods for sediment monitoring are described
in terms of direct and indirect approaches. Different approaches toward the establishment of a sediment rating curve are examine thoroughly. Techniques of sediment modelling are summarized via depiction of various hydrological and sediment models
at the watershed scale. The paper ends with the discussion of future developments in suspended sediment studies at the watershed scale.
The spatial variability of overbank sedimentation on river floodplains
Analyse isotopique ; Cours d'eau ; England ; Granulométrie ; Géochimie ; Microrelief ; Plaine d'inondation ; Royaume-Uni ; Sédimentation ; Transport sédimentaire ; Variation spatiale
England ; Floodplain ; Geochemistry ; Grain size distribution ; Isotope analysis ; Microrelief ; Sediment transport ; Sedimentation ; Spatial variation ; Stream ; United Kingdom
The study reported uses Cs 137 measurements on sediment cores to investigate the spatial variability of sediment deposition on selected floodplain reaches of five British lowland rivers. Attention is given both to the overall reach and to more
detailed investigations of small areas. The observed spatial patterns of sediment deposition are interpreted in terms of the major controls involved, which include the floodplain microtopography and morphology. The relationship between the grain size
composition of deposited sediment and sedimentation rate is also considered.
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.
Organically bounded carbon which sediments during the vegetative season in the Müggel Lake being one of the water supply sources for the capital of GDR amounts of 10 % of the carbon quantity which is bounded by primary production during the same
period of time. The sedimentary process and the composition of sediments with regard to their contents of combined carbon, nitrogen and phosphorus and other substances are discussed. Moreover, conclusions are presented concerning the history of this lake
Sediment storage and yield in an urbanized karst watershed
Cave ; Doline ; Karst ; Sediment budget ; Sediment transport ; Tennessee ; United States of America ; Urban area ; Watershed
This paper presents a preliminary assessment of fluvial sediment storage and yield in an urbanized, karst watershed. The AA. aim to identify and quantify the function of caves and sinkholes within the context of a sediment budget with 3 specific
objectives : to investigate the function (source or sink) of sinkholes with respect to sediment transport; to demonstrate how sinkhole sedimentation rates can be used as an indicator of basin sediment yield from some sinkhole drainage basins; and to determine
the relative contribution of a major cave system to a preliminary sediment budget for a karst watershed.
Lake-sediment-based evaluation of recent sediment yield from a small appalachian watershed, Thompson lake, Virginia
Bassin-versant ; Bilan sédimentaire ; Etats-Unis ; Lac ; Ouragan ; Précipitation ; Susceptibilité magnétique ; Sédiment lacustre ; Sédimentologie ; Utilisation du sol ; Variation spatiale ; Virginia
Hurricane ; Lacustrine sediment ; Lake ; Land use ; Magnetic susceptibility ; Precipitation ; Sediment budget ; Sedimentology ; Spatial variation ; United States of America ; Virginia ; Watershed
In this study, sediments from Thompson Lake, Virginia, are used to study the last 30 years of sediment yield from the 3.8 km2 contributing catchment. Sediment yield changes at this site are found to be related primarily to precipitation history
. This result as well as an established relationship between sediment magnetism and particle size allow for a simple evaluation of sediment yield frequency and magnitude. Two magnetic susceptibility peaks identified in the sediment record are hypothesized
to represent discrete flood sediment strata, one resulting from hurricane Agnes in 1972.
Physiographically controlled allometry of specific sediment yield in the Canadian Cordillera : a lake sediment-based approach
Bassin-versant ; Bilan sédimentaire ; British Columbia ; Canada ; Charge en suspension ; Modèle ; Montagne ; Sédiment lacustre ; Sédimentologie ; Transfert sédimentaire
British Columbia ; Canada ; Lacustrine sediment ; Model ; Mountain ; Sediment budget ; Sediment transfer ; Sedimentology ; Suspended load ; Watershed
It is generally supposed that specific sediment yield declines as the drainage basin area increases, as part of the mobilized sediment becomes trapped in the downstream cascade of storage zones. Using a larger data set of lake sediment-based
estimates of long-term sediment yield, sub-regional patterns of specific yield have been investigated for the Canadian Cordillera. The results suggest that no single model of sediment yield is adequate to describe sediment transfer processes in the Canadian
Nowadays any investigation of recent marine sediments is carried out with pore water analysis. Their results contribute considerably to the solution of diagenetic and deposite-formation processes of the geological past. (HL).
Use of floodplain sediment cores to investigate recent historical changes in overbank sedimentation rates 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 sedimentation rates 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
Influence of storm-related sediment storage on the sediment delivery from tributary catchments in the Upper Waipaoa River, New Zealand
Cross section ; Cyclone ; Fluvial terrace ; Gully erosion ; Mass movement ; New Zealand ; North Island ; Precipitation ; Rainstorm ; Sediment budget ; Sediment load ; Stream ; Watershed
Sediment delivery ratios focused on the influence of storm-related sediment storage are measured at Matakonekone and Oil Springs tributaries of the Waipaoa River basin, east coast of New Zealand. The terrace deposits of both tributaries show
abundant evidence of storm related sedimentation, especially sediment delivered from Cyclone Bola, a 50 year return rainfall event which occurred in 1988. The sediment delivery ratio is calculated by dividing the volume of sediment transported from
a tributary to the main stream by the volume of sediment generated at erosion sites in the tributary catchment.
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.