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
The objectives of this study are to make an assessment of the variability in dry sediment bulk density (dbD) between and within small flood retention ponds in central Belgium and to look at the factors controlling this variability. It will further
be evaluated if the various existing dry sediment bulk density prediction techniques for large reservoirs can be used in another environment, i.e. small ponds, and what the implications of their use are for the calculation of sediment yield.
The AA. present a spatially distributed model for the calculation of sediment delivery to river channels (SEDEM : SEdiment DElivery Model) at a catchment scale (100 to 10 000 km2). The model was applied on several catchments in central Belgium
for which medium-term sediment export measurements as well as spatially distributed data on topography, land use and soils are available.
Correction factors for estimating suspended sediment export from loess catchments
Belgium ; Grain size distribution ; Loess ; Sediment transport ; Soil erosion ; Suspended load ; Watershed
This study focuses on problems related to estimating the exact exported suspended sediment quantity and quality from flow-proportional samples taken at a fixed height at the outlet of a small, agricultural catchment in central Belgium
. The application of 2 correction factors, one for the water depth and one for the concentration gradient, leads to a reduction of the estimated total sediment export. This paper therefore emphasizes that point sampling of suspended sediment is biased
and that a method should be incorporated to correct the sediment export in terms of quantity and quality.
Impact of historic land-use change on sediment delivery to a Chesapeake Bay subestuarine delta
Action anthropique ; Bassin-versant ; Chesapeake Bay ; Delta ; Etats-Unis ; Habitat ; Maryland ; Modèle ; Paléo-écologie ; Taux de sédimentation ; Transport sédimentaire ; Utilisation du sol
Delta ; Habitat ; Human impact ; Land use ; Maryland ; Model ; Palaeo-ecology ; Sediment transport ; Sedimentation rate ; United States of America ; Watershed
This paper presents an approach for combining palaeoecological reconstructions of sedimentation history with physically based models of delta evolution to quantify the impact of historic land-use change on sediment delivery to an estuarine delta
. The approach yields simulations of the morphology and evolution of a delta that developed as a result of human-induced high sediment supply and provides estimates of watershed sediment supply rates corresponding to observed delta sedimentation rates. Using
La dénudation des Alpes par érosion et son rôle comme source de sédiments a connu des changements majeurs au cours du Quaternaire, en fonction des glaciations et déglaciations. Les flux de sédiments de 16 bassins alpins majeurs ont été quantifiés en
évaluant les volumes de sédiments déposés dans les vallées et les lacs formés, pour la plupart, après le retrait des derniers glaciers, soit depuis 17 000 BP.
Floodplain ; Fluvial processes ; Heavy metals ; Historical geography ; Land use ; Mining activity ; Nineteenth Century ; Sedimentation ; Tracer ; Twentieth Century ; United States of America ; Wisconsin
Changes in land use practices following European settlement in the 1830s produced accelerated sedimentation on virtually all valley floors in the Blue River Watershed, Wisconsin. The contamination of sediments by Pb and Zn mining allowed
to calculate cross-valley rates of flood plain sedimentation for three time periods : the pre-mining period (1830-1900), the mining period (1900-1920), and the post-mining period (1920-1997). The AA. also examine geomorphic lags in channel adjustments
Effects of historical land use on sediment yield from a lacustrine watershed in central Chile
Années 1943-1994 ; Bilan sédimentaire ; Chili ; Datation isotopique ; Palynologie ; Photo-interprétation ; Photographie aérienne ; Système d'information géographique ; Sédiment lacustre ; Utilisation du sol
Aerial photography ; Chile ; Geographical information system ; Isotope dating ; Lacustrine sediment ; Land use ; Palynology ; Photointerpretation ; Sediment budget
Sediment yield in the San Pedro Lake watershed, inferred from sedimentation in the lake, can be related to land use changes shown on aerial photographs taken during the period 1943-1994. To study effects of these changes, the AA. took a core from
the centre of the lake and estimated sedimentation rates by Pb 210 dating, which they checked with Cs 137 and pine pollen. Sediment yield between 1955 and 1994 closely tracks the total land use change that can be detected on sets of aerial photographs
Determination of the sediment transport in an armoured gravel-bed river
Sediment transport dynamics. Special issue
Carrying capacity ; Comparative study ; Discharge ; Europe ; Geographical information system ; Gravel ; Methodology ; Meuse ; Sediment load ; Sediment transport ; Stream
For 3 periods of 9, 8 and 17 years sediment transport computations are made with 2 series of relationships between sediment transport (Qb) and discharge (Q) in which the condition of the armour layer is taken into account. These sediment-transport
of maps of bed levels in different years results in a map with spatial distributions of erosion and sedimentation.
Composition and flux of Holocene sediments on the eastern Laptev Sea shelf, Arctic Siberia
Arctique océan ; Carte bathymétrique ; Datation C 14 ; Fond sous-marin ; Holocène ; Mer de Laptev ; Micro-organisme ; Paléo-environnement ; Plate-forme continentale ; Russie d'Asie ; Réchauffement climatique ; Sibir' ; Sédiment marin ; Taux de
sédimentation
Arctic Ocean ; Asian part of Russia ; Bathymetric chart ; C 14 dating ; Climatic warming ; Continental shelf ; Holocene ; Marine sediment ; Micro-organism ; Palaeo-environment ; Sea floor ; Sedimentation rate ; Siberia
The aim of this paper is to investigate various Holocene sediment records from a high-resolution core on the inner eastern Laptev Sea Shelf. The AMS C 14 chronology of the core allows reliable calculation of shelf sediment budgets. Because
Factors controlling sediment yield from small intensively cultivated catchments in a temperate humid climate
Belgium ; Cultivated land ; Model ; Multiple regression ; Sediment budget ; Soil erosion ; Temperate zone ; Watershed
Data on sediment yield from 26 small cultivated catchments (10-10 000 ha) in central Belgium were collected based on sedimentation rates in small flood retention ponds. Various catchment properties were analysed in order to understand the large
variation in observed sediment yield. A multiple regression model including 3 morphological catchment properties is a valuable tool to predict total sediment yield from catchments in central Belgium. This model has an efficiency of 0.81. The importance
of spatially distributed parameters within catchments are some of the major reasons that the proposed model does not explain all observed variation in sediment yield.
Erosion and sediment delivery following removal of forest roads
California ; Drainage ; Erosion control ; Forest ; Geotechnics ; Gully erosion ; Impact ; Mass movement ; Road ; Sediment budget ; Slope gradient ; Soil erosion ; United States of America ; Watershed
Erosion control treatments were applied to abandoned logging roads in California, with the goal of reducing road-related sediment input to streams and restoring natural hydrologic patterns on the landscape. This paper evaluates the erosion
and sediment delivery from treated roads based on measurements after the 1997 storm.
Biogenic process ; Biogeography ; Dammed lake ; Lacustrine sedimentation ; Lake ; Longitudinal section ; Montana ; Mountain ; Periglacial features ; Stream flow ; United States of America
Two adjacent beaver-pond sequences of seven ponds each were examined along the eastern boundary of Glacier National Park, Montana, to determine spatial patterns and amounts of sedimentation, both within individual ponds and along pond sequences
Dammed lake ; European part of Russia ; Lacustrine deposit ; Lacustrine sedimentation ; Lake ; Metals ; Moscow ; Pollution ; Silt
Caractéristiques générales du lac dee barrage. Formation et accumulation de sédiments de fond. Accumulation de métaux dans les sédiments de fond. Accumulation dans les vases de xénobiotiques organiques.
Residence times of alluvium in an east Texas stream as indicated by sediment color
Alluvium ; Geochemistry ; Indicator ; Sediment transport ; Sedimentology ; Stream ; Texas ; United States of America
The systematic changes in iron geochemistry often experienced by sediments deposited in an anaerobic environment, such as stream channel or waterlogged floodplain, are used here as an indicator of residence time over contemporary time scales
Rates of sediment supply to Arroyos from upland erosion determined using in situ produced cosmogenic Be10 and Al26
Using Be10 and Al26 measured in sediment and bedrock, the AA. quantify rates of upland erosion and sediment supply to a small basin in northwestern New Mexico. This and many other similar basins in the southwestern United States have been affected
by cycles of arroyo incision and backfilling several times in the past few millennia. Differences between nuclide concentrations measured in sediment sources and reservoirs reflect sediment residence times and indicate that subcolluvial bedrock weathering
on hillslopes supplies more sediment to the basin than erosion of exposed bedrock.
Use of mineral magnetic measurements to investigate soil erosion and sediment delivery in a small agricultural catchment in limestone terrain
Alabama ; Cultivated land ; Forecast ; Magnetic susceptibility ; Methodology ; Model ; Sediment budget ; Slope gradient ; Soil erosion ; Thematic mapping ; United States of America ; Watershed
In this study, variations in surface magnetism are analyzed to determine patterns of erosion and sedimentation in a small agricultural catchment in northwestern Alabama (USA). Magnetic indicators of erosion are combined with published soil
morphology, Cs-137 and short-term suspended sediment data from this former experimental watershed to evaluate long-term sediment delivery. The results suggest the need for continued refinement of magnetic techniques for purposes of erosion model validation
Runoff-induced sediments were collected in the Hallamish dune field for 4 years (1990-1994). Runoff and consequently water-transported sediments were generated on the dunes owing to the presence of a thin microbiotic crust. These sediments were
analysed for their particle-size distribution, carbonate content, and organic matter content. The results were compared to the slope parent material, i.e. the crust and the underlying sand, as well as to playa sediments, which are scattered within
Interstorm surface preparation and sediment detachment by vehicle traffic on unpaved mountain roads
The AA. use rainfall simulation to investigate sediment production associated with one common maintenance practice in northern Thailand, and to study sediment detachment by motorcycles and pickup trucks on unpaved roads. Additionally
they incorporate physical property measurements, road usage information and simulation results to determine links between sediment production on roads and interstorm preparation. The AA. focus on processes that determine sediment production during typical seasonal
Estimation of temporally averaged sediment delivery ratio using aggradational terraces in headwater catchments of the Waipoa River, North Island, New Zealand
Gully erosion ; New Zealand ; North Island ; Precipitation ; Reforestation ; Sediment budget ; Sediment transport ; Slope dynamics ; Soil erosion ; Time series ; Twentieth Century ; Watershed
sediment source, with minor inputs from other erosion processes such as landsliding and earthflows. Results allow comparison of past and present SDRs, as well as permitting derivation of an equation that predicts sediment delivery ratios for this land type