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.
Aeolian features ; China ; Environment ; Grain size distribution ; Human impact ; Isotope analysis ; Lacustrine sedimentation ; Lake ; Qinghai ; Sedimentation rate ; Wind erosion
Here the AA. report the preliminary results of Cs 137 measurements on the lacustrine sediments of Dalian Lake, Qinghai Province, China. The objectives were to determine sediment accumulation rates and trace environmental changes in the surrounding
The upper and middle drainage basin of the Yellow River has been divided into 4 major sediment and water source areas. A series of databases of runoff and sediment yields from these source areas and for the corresponding quantities of sedimentation
in the lower Yellow River channel have been established. On this basis, a set of multiple-regression equations has been established that define the relationships between sedimentation in the lower Yellow River and the yearly or event-based runoff and sediment
Les processus de sédimentation dans les zones d'embouchure des cours d'eau
Bilan sédimentaire ; Cours d'eau ; Delta ; Embouchure ; Plate-forme continentale ; Sédimentaire ; Sédimentation ; Transfert sédimentaire
Continental shelf ; Delta ; River mouth ; Sediment budget ; Sediment transfer ; Sedimentary ; Sedimentation ; Stream
Discussion des caractéristiques générales et des traits régionaux du transfert sédimentaire pour les zones d'embouchure de différents types morphologiques et génétiques. Estimations grossières du volume potentiel de l'accumulation de sédiments pour
River sedimentation and channel adjustment of the lower Yellow River as influenced by low discharges and seasonal channel dry-ups
Capacité de charge ; Chine ; Cours d'eau ; Débit ; Géométrie hydraulique ; Huanghe ; Sédimentation ; Variation saisonnière
Carrying capacity ; Channel geometry ; China ; Discharge ; Huang He ; Seasonal variation ; Sedimentation ; Stream
Fluvial sedimentation can be classified as one of the 3 types in terms of different morphological units, i.e., vertical overbank deposition, vertical deposition on the riverbed and lateral deposition on the riverbank. With the example of the lower
Yellow River, the 3 types of sedimentation have been studied in relation to channel adjustment, emphasizing the changes under the conditions of low discharge and seasonal desiccations since 1986.
Changes in sediment yield of the Yellow River basin of China during the Holocene
Action anthropique ; Bassin-versant ; Bilan sédimentaire ; Chine ; Datation C 14 ; Holocène ; Huanghe ; Loess ; Plateau ; Taux de sédimentation
C 14 dating ; China ; Holocene ; Huang He ; Human impact ; Loess ; Plateau ; Sediment budget ; Sedimentation rate ; Watershed
This research reconstructs the changes in sediment yield of the Yellow River based mainly on a large number of C 14 dates collected from the literature. The changes in sediment yield are ascribed to both natural and anthropogenic reasons, in which
the latter became important in the late Holocene. It is clear that human activities have augmented natural soil erosion by about 41% in the Yellow River Basin. The overall pattern of anthropogenic sediment yield shows an accelerated increasing trend, which
The AA. measured accumulation rates of sediment in 6 cores from marl- and sand-based marshes of northern Belize and compared biogeochemical characteristics to assess recent wetland history (- 1850 to present). Sediment depth increments were analysed
for bulk density, LOI, nutrients, snail shell density and species diversity. Cores were dated. Increased sediment accumulation by human activities such as soil washout from adjacent roads was recorded in a sand-based marsh near roads. Sediment cores
Sediment yield and storage variations in the Négron River catchment (south western Parisian Basin, France) during the Holocene period
Agricultural land use ; Colluvium ; France ; Holocene ; Human impact ; Lithology ; Loess ; Periglacial features ; Poitou-Charentes ; Quaternary ; Sediment budget ; Vienne ; Watershed
This study aims to attempt a sediment budget for the Holocene period using different approaches (quantification of present flux of solid material, of various sedimentary stores, and of rates of sedimentation), and to compare the values obtained
by each approach. The mean sediment yield of the catchment will be compared to those of its various sub-basins. In the Négron catchment, the values of sediment yield differ widely according to the parameters used for calculation. Sediment yield varies
Determining sediment source areas in a tropical river basin, Costa Rica
Bank erosion ; Carrying capacity ; Costa Rica ; Discharge ; Hydrology ; Land use ; Rainstorm ; Sediment budget ; Sediment transport ; Soil erosion ; Tropical zone ; Water balance ; Watershed
Four hydrologic events were studied at three gauging stations in the Pejibaye river basin. The objective was to determine if the sediment passing the gauging stations originated in the forested area, the pasture, or the cultivated area during
these four rainstorms. A sub-objective was to determine if sediment had been eroded or deposited in the channel before the studied events in order to determine if any of the sediment discharge consisted of re-suspended material.
Coastal environment ; Coastal marsh ; Delta ; Humid environment ; Isotope dating ; Sea level ; Sedimentation ; Texas ; United States of America
Using a simple 210Pb-dating model, the AA. measured sedimentation rates in cores from the Trinity, Lavaca-Navidad, and Nueces bayheadfluvial-deltaic systems in Texas where more than 2000 ha of wetlands have been lost since the 1950s. The relative
magnitudes of sedimentation and wetland loss correlate with several parameters that define the differing fluvial-deltaic settings, including size of coastal drainage basin, average annual rainfall, suspended sediment load, thickness of Holocene mud
Human-induced overbank sedimentation in the foreland of the Eastern Sudety Mountains
Action anthropique ; Alluvion ; Déboisement ; Europe ; Europe centrale ; Granulométrie ; Holocène ; Montagne ; Métaux lourds ; Paléo-environnement ; Plaine d'inondation ; Sudety ; Sédimentation
Alluvium ; Central Europe ; Deforestation ; Europe ; Floodplain ; Grain size distribution ; Heavy metals ; Holocene ; Human impact ; Mountain ; Palaeo-environment ; Sedimentation ; Sudety
Analysis of a 2-3 m thick vertical sequence of fine-grained overbank alluvial sediments on the foreland of the Eastern Sudety Mountains reveals that these sediments resulted from human land use changes. Since at least Early Medieval times
, and possibly even earlier, the Glubczyce Plateau has been a deforested region. Despite the mountainous character of the headwater area of rivers in the Eastern Sudety foreland, sediment transfer from sub-mountainous loess-covered uplands, induced by human
This review draws examples from a wide range of marine environments, including estuaries, the intertidal zone, continental shelves and slopes, and the deep sea. It firstly considers sediment stabilisation, slope failure, sediment mixing
, biodeposition, sediment compaction, and hydrodynamic effects. This is followed by a consideration of 2 extremes of the ecological pyramide, the effects of marine meiofauna and marine vertebrates. The central role of faunal mucus and extracellular polymeric
Les métaux lourds dans les sédiments de fond de la Volga supérieure et inférieure
Analyse en composantes principales ; Analyse quantitative ; Cours d'eau ; Ivankovo ; Lac de barrage ; Métaux lourds ; Pollution ; Qualité de l'eau ; Russie d'Europe ; Sédiment lacustre ; Volga
Dammed lake ; European part of Russia ; Heavy metals ; Lacustrine sediment ; Pollution ; Principal components analysis ; Quantitative analysis ; Stream ; Volga ; Water quality
Etude de la teneur en métaux lourds dans ces sédiments de la Volga entre Volgograd et les eaux côtières à l'embouchure. Les sédiments du lac de barrage d'Ivankovo sont contaminés significativement par Cu, Zn et dans une moindre mesure par Co et Ni
. L'analyse de l'état de pollution des sédiments est réalisée par la méthode des composantes principales.
Dammed lake ; Ecology ; European part of Russia ; Geomorphology ; Hydrology ; Lacustrine sediment ; Lake ; Organic materials ; Palaeomagnetism ; River bed ; Stratification ; Yaroslavl
Etude des propriétés physiques des carottes de sédiments de la partie du lit de la Volga dans la mouille du lac de barrage de Rybinsk. Relation entre les propriétés physiques des sédiments et l'évolution des processus géomorphologiques ainsi que la
quantité de matière organique dans les dépôts. Possibilité d'utilisation des paramètres magnétiques des sédiments pour la reconstitution d' informations sur certains processus écologiques et hydrologiques.
Alluvial fans as records of Holocene sediment yield in the central Great Plains of southwest Nebraska
Alluvial cone ; C 14 dating ; Climatic variation ; Geochronology ; Holocene ; Nebraska ; Palaeosol ; Quaternary ; Sediment budget ; Stratigraphy ; United States of America
On alluvial fans, increased rates of sedimentation are directly related to increased sediment yields from their watersheds. Since well developed soils imply prolonged landscape stability, soils that are buried by alluvial-fan deposits are evidence
of a shift, at least locally, toward increased sediment yields. The objective of this paper is to propose a Holocene history of sediment yield increases in the central Great Plains based on the record that buried alluvial-fan soils provide.
Influences of human activities on sediment discharge from devastated weathered granite hills of southern China : effects of 4-year elimination of human activities
Biomass ; China ; Erodibility ; Granite ; Human impact ; Jiangxi ; Land use ; Plant cover ; Rill wash ; Sediment budget ; Soil erosion ; Watershed
Data on sediment yields, percentages of peak storm runoff and fern undergrowth and litter cover extent in two basins, one a control from which people have been excluded since 1997, and the other where normal harvesting practices are permitted, were
used to evaluate how human activity affects sediment discharge. The 4-year period of control practice was to short to affect the relationship between peak rainfall and peak storm runoff and the fern and litter covers and their amounts, but long enough
to contribute to the reductions in sediment discharge in the control basin by decreasing erodibility.
Overbank sediment deposition patterns for straight and meandering flume channels
Charge en suspension ; Cours d'eau ; England ; Expérimentation ; Géométrie hydraulique ; Lit fluvial ; Méandre ; Oxfordshire ; Plaine d'inondation ; Royaume-Uni ; Sédimentation ; Transport sédimentaire
Channel geometry ; England ; Experimentation ; Floodplain ; Meander ; Oxfordshire ; River bed ; Sediment transport ; Sedimentation ; Stream ; Suspended load ; United Kingdom
Experiments with the 10 m Flood Channel Facility at HR Wallingford, UK, indicate a fundamental dependency of the overbank deposition pattern of channel suspended sediments on channel planform. Two experiments with straight channel showed deposition
Establishing sediment budgets for two small lowland agricultural catchments in the UK
Bank erosion ; Cultivated land ; Derbyshire ; Digital elevation model ; Drainage ; England ; Geographical information system ; Isotope analysis ; Sediment budget ; Soil erosion ; Suspended load ; United Kingdom ; Watershed
This paper reports the results of an investigation aimed at establishing detailed sediment budgets for 2 small (
. The study catchments are extensively underdrained and particular attention was directed towards establishing the importance of sediment outputs from the tile drain systems within the overall sediment budget.
Outcrops near Gniew in the one-time hinterland of the Pomeranian-phase ice sheet at its maximum extent were subject to lithofacial analyses of sediments, as well as faunistic studies and direct dating of the marine fauna presented within species
sediments, is linked with the anaglacial phase of the upper stadial (Leszczyński phase). The entire mass of transgressive outwash sediments became overlain with the morainic clay of the Leszczyński-phase ice sheet. - (BJ)
Effects of woody debris on channel morphology and sediment storage in headwater streams in the Great Smoky Mountains, Tennessee-North Carolina
Bank erosion ; Channel geometry ; Dendrochronology ; Fluvial dynamics ; Forest ; Mountain ; North Carolina ; Sediment transport ; Stream ; Tennessee ; United States of America
This study invesigates the effect of coarse woody debris, CWD, on bankfull channel dimensions and in-channel sediment storage along second-order streams. Comparisons are made between streams that have experienced recent debris slides and those
, but the volume of sediment stored in the channel behind CWD obstructions is up to 4 times greater than the volume of sediment represented by bank erosion associated with CWD.