A soil erosion map of the Lesotho lowlands. A case study using visual interpretation of multitemporal Landsat false colour composites in Sediment sources, sediment residence time and sediment transfer-Case studies of soil erosion in the Lesotho
The project is made within the framework of a larger research programme on the relations between sediment production, sediment residence time and sediment delivery in different climates and geomorphological environments.
Sediment transport under different types of vegetation in Sediment sources, sediment residence time and sediment transfer-Case studies of soil erosion in the Lesotho lowlands.
The standard conditions of erosion rates (on albaqualps respective argiudolls soils) is considered to be described by two areas with undisturbed grass cover. Measured sediment concentration in runoff from these were compared with two study areas
Influence des sédiments des eaux sous-marines sur le bilan hydrique et salin des océans
Bilan hydrique ; Eau de mer ; Géochimie ; Océan ; Océan mondial ; Sédiment marin ; Sédimentation marine
Geochemistry ; Marine sediment ; Marine sedimentation ; Ocean ; Sea water ; Water budget ; World ocean
Méthode de calcul des eaux lors de la lithogenèse des sédiments marins argileux. Evaluation régionale de la quantité d'eaux sédimentées sous-marines pour la partie supérieure des sédiments de l'Océan mondial.
Sedimentation in an Alpine lake during deglaciation, Okanagan Valley, British Columbia, Canada
British Columbia ; Canada ; Déglaciation ; Géographie de l'Amérique ; Montagne ; Paléocourant ; Processus de sédimentation ; Quaternaire ; Sédiment lacustre ; Sédimentation ; Série stratigraphique ; Terrasse ; Varve
Description de quatre séries stratigraphiques dans les sédiments lacustres. On en déduit les processus de sédimentation. Proposition d'un mécanisme de glissement sous-lacustre basé sur la compaction différentielle des couches de sédiments lacustres
et d'un modèle de sédimentation lacustre alpine basé sur les variations des processus de dépôt avec l'éloignement de la marge glaciaire en distance et en temps.
This review aims to critically evaluate the potential and problems of using reservoir sediments as temporal records of pollutant inputs. Reservoirs are generally located close to urban and industrial sources of pollution and accumulate sediment
rapidly and over similar time periods to major emissions of pollutants. Current understanding of the processes of sedimentation and resulting distributions are reviewed. Some significant differences between sedimentation in lakes and reservoirs
Utilisation de modèles physiques représentant simultanément l'arrachement des sédiments, leur dépôt et les débits entrants latéraux. Description de l'écoulement non permanent et de la sédimentation dans les rigoles par des équations de continuité.
Sediment yield mapping using small dam sedimentation surveys, Southern Tabelands, New South Wales
Aménagement hydraulique ; Australie ; Barrage-réservoir ; Bassin-versant ; Cartographie thématique ; Erosion des sols ; New South Wales ; Qualité de l'eau ; Sédimentation ; Taux de sédimentation ; Utilisation du sol
Australia ; Catchment area;Watershed ; Dam ; Hydraulic works ; Land use ; New South Wales ; Sedimentation ; Sedimentation rate ; Soil erosion ; Thematic mapping;Thematic cartography ; Water quality
Using an empirical sediment yield equation derived from sedimentation surveys of fourteen small reservoirs, the sediment yields of subcatchments of an adjacent drainage basin were mapped. The results are consistent with geomorphic processes
and with documented effects on sediment yields of land use intensification.
Sustained reworking of hydraulic mining sediment in California: G.K. Gilbert's sediment wave model reconsidered
California ; Human impact ; Mining activity ; Model ; Sediment budget ; Sierra Nevada ; Soil erosion ; United States
Hydraulic gold mining in the Sierra Nevada generated large volumes of sediment in the 19th century. Topographic surveys document several meters of mining sediment erosion in the bassin following a 1986 flood. The continued storage and mobility
of sediment in the bassin indicate increased sediment loads over pre-mining levels and call for reevaluation of Gilbert's symmetrical sediment wave model. In basins where channel storage is substantial, a sediment wave should be right-skewed in respect to time
due to protracted sediment releases from easily eroded, unconsolidated deposits.
Rates of overbank sedimentation on the floodplains of British lowland rivers documented using fallout 137Cs
Bassin-versant ; England ; Fluviatile ; Géochimie ; Isotope ; Plaine d'inondation ; Royaume-Uni ; Sédimentation ; Taux de sédimentation ; Traceur ; Utilisation agricole du sol ; Utilisation du sol
Agricultural land use ; England ; Floodplain ; Fluvial processes ; Geochemistry ; Isotope ; Land use ; Sedimentation ; Sedimentation rate ; Tracer ; United Kingdom ; Watershed
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
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
and the sediment transport and deposition processes involved.
Using sediment fingerprints to assess sediment-budget errors, North Halawa Valley, Oahu, Hawai, 1991-92
Aeolian features ; Aerosol ; Error ; Hawaii ; Methodology ; Sediment budget ; Suspended load ; Tropical zone ; Watershed
Reliable estimates of sediment-budget errors are important for interpreting sediment-budget results. The AA. modified the sediment fingerprinting approach to qualitatively evaluate compensating errors in an annual (1991) fine sediment budget
for the North Halawa Valley, a mountainous, forested drainage basin on the island of Oahu, during construction of a major highway. Sediment and aerosol budgets were developed using data collected in 1991. Differences between sediment-budget and aerosol-budget
imbalances provide a measure of compensating errors in the sediment budget.
Variability in sediment supply, transfer and deposition in an upland torrent system : Iron Crag, northern England
Alluvial cone ; Cumbria ; England ; Grain size distribution ; River bed ; Sediment budget ; Sediment load ; Sediment transport ; Slope gradient ; Spatial variation ; Stream ; Torrent ; United Kingdom
The aim of this study is to examine spatial variations and process controls on sediment transfer in an upland torrent system (hillslopes, channel and fan). The study site is Iron Crag, a small torrent system situated in the northern Lake District
. Partcle size analysis of hillslope sediments trapped during transport suggests sediment calibre is controlled primarily by sediment source. Freeze-thaw and rainfall processes impart a weak but recognizable size sorting signature on the trapped sediments
. The importance of the channel-fan coupling is clearly demonstrated in that more than 90 per cent of fan sedimentation is derived from channel sediment sources.