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.
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.
A method for error analysis of sediment yields derived from estimates of lacustrine sediment accumulation
Analyse de régression ; Bilan sédimentaire ; British Columbia ; Canada ; Erreur ; Holocène ; Lac ; Montagne ; Méthodologie ; Sédiment lacustre ; Sédimentologie
British Columbia ; Canada ; Error ; Holocene ; Lacustrine sediment ; Lake ; Methodology ; Mountain ; Regression analysis ; Sediment budget ; Sedimentology
In this paper data from a series of alpine lakes in British Columbia are applied to develop a new method for deriving error estimates for measured sedimentary parameters. Regression surfaces fitted to point values of sediment mass are used to model
the physically controlled spatial variability of sedimentation. Deviations from these surfaces are assumed to represent remaining unstructured variance, which constitutes a conservative error estimate. The associated gains in precision justify multicore
approaches to lake sediment-based reconstructions of sediment yield.
Grain size distribution ; Lacustrine sediment ; Lake ; Methodology ; Minnesota ; Model ; Sediment budget ; Sedimentology ; United States of America ; Watershed
The aim of this study was to develop a method of assessing the sources and depositional record of historic sediments in a lake basin with a large catchment, and reconstruct how sediment provenance changed over time. The AA. first used known mixtures
sediment to an isolated depositional basin, Lake Pepin. The beds of each river system are composed of sediments derived from glacial deposits of different ages and geographic origins, so the method should effectively distinguish the different sources.
Suspended sediment load during floods in a small stream of the Dolomites (northeastern Italy)
Suspended sediment load was analyzed in a small, high-gradient stream of the Eastern Italian Alps which was instrumented to measure discharge and sediment transport. The ratio of suspended to total sediment yield and the relations between sediment
concentration and water discharge were analyzed for 7 floods which occurred from 1991 to 1996 in summer and autumn. Different patterns of hysteresis in relation between suspended sediment and discharge were related to types and locations of active sediment
This paper reports the results of a study which was set up to examine the linkage between sediment export and within-basin processes in a small catchment in the Belgian Loam Belt. Sediment characteristics were monitored at the catchment outlet
. Furthermore, monthly surveys in the catchment were conducted to study various soil surface conditions and erosion and sedimentation patterns. The main objectives of this study are 1) to detect variations in sediment yield on different time-scales, and 2
) to relate the sediment yield at the outlet of the basin to processes within the catchment.
Alberta ; Canada ; Dating ; Geochronology ; Lacustrine sediment ; Palaeo-environment ; Palaeomagnetism ; Reliability
Les AA. évaluent si des changements dans la déclinaison, dont l'âge absolu a été déterminé, peuvent être utilisés pour dater des sédiments de lac récents à une échelle plus petite que centenaire. Trois points limitant de telles études sont abordés
: la collecte de sédiments récents de lac non perturbés, l'évaluation de la fiabilité des données géomagnétiques et la comparaison des données contenues dans les sédiments de lac et les données historiques. Discussion des résultats d'une chronologie
géomagnétique de 793 années obtenue à partir des sédiments à lamination annuelle du lac Rainbow.
The results of four-year measurement of suspended sediments in the Holedeč profile at the Blšanka river in the NW Bohemia. The main attention is paid to the typology of the individual regime situation and to geochemical analysis of suspended
sediment particles and active bank sediments. - (MS)
Sediment yield on a devasted hill in southern China : effects of microbiotic crust on surface erosion process
Biogenic process ; China ; Duricrust ; Forest ; Human impact ; Jiangxi ; Rill wash ; Sediment budget ; Soil erosion ; Vegetation degradation ; Watershed
In order to clarify the surface erosion processes in one area of devasted hills in southern China, the AA. measured the sediment yield and surface erosion depth in terms of catchment scale, and carried out in situ sprinkling experiments, focusing
on the spatial variability of surface conditions and the sources of sediment.
The primary objectives of this initial study were to prepare sediment budgets for rill networks developed on a natural soil under simulated rainfall in a laboratory flume (University of Toronto, Scarborough), and identify the effect of confluences
on rill hydraulics and sediment flux patterns. Results indicate the value of detailed sediment budgets in interpreting their water and sediment flux records, and the necessity of linking such measurements for erosion plots and hillslope segments to rill
Carbonate ; Coastal dynamics ; Coastal environment ; Grain size distribution ; Heavy minerals ; Marine sediment ; Red Sea ; Reef ; Saudi Arabia ; Sediment transport ; Seismic reflection
of the sediments in the shore zone profile varies with different subenvironments. The shore zone sediments are composed mostly of skeletal carbonate sands. High Mg-calcite and aragonite are the dominant carbonate minerals like the shallow water carbonate
Characteristics of sediment deposits formed by intense rainfall events in small catchments in the Belgian Loam Belt
Belgium ; Grain size distribution ; Land use ; Loam ; Precipitation ; Sediment budget ; Sediment transport ; Soil erosion ; Spatial distribution ; Vegetation ; Water pollution ; Watershed
This paper discusses the results of 2 detailed field surveys, carried out after extreme rainfall events in springtime. The objectives are 1) to investigate to what extent the sediment delivery ratio of a catchment scale is controlled by the spatial
organisation of land use in the absence of spatial control measures, and 2) to compare the size characteristics of the deposited sediment with the size characteristics of the source soil material. Such information may be used to optimise the spatial
distribution of land-use in order to reduce sediment and pollutant delivery to streams.
Soils in the Holocene alluvial sediments of the Rio Fraja Valley, Spain : in situ or soil-sediments ?
of erosion, sedimentation and pedogenesis during the last 4000 years. The data sets allow to distinguish soils formed in situ from transported soil-sediments. The AA. suggest that in alluvial sequences magnetostratigraphic records can be used to distinguish
periods of land surface stability, when pedogenetic processes prevailed under a vegetation cover, and morphodynamically active periods, in which soil erosion, transportation and sedimentation predominated.
Asian part of Russia ; Dammed lake ; Eastern Siberia ; Grain size distribution ; Irkutsk ; Lacustrine sedimentation ; Lake ; Seasonal variation ; Suspended load ; Water regime
Relation entre cette sédimentation et les conditions d'exploitation de ce réservoir entre 1972 et 1998. Relation entre la taille et les types de sédiments et le champ de vitesse du courant. Tendance temporelle de la répartition des sédiments de fond
Shaping Sydney Harbour : sedimentation, dredging and reclamation 1788-1990s
Aménagement fluvial ; Australie ; Dragage ; Environnement ; Estuaire ; Géographie historique ; Impact ; New South Wales ; Peuplement ; Port ; Siècle 18 ; Siècle 19 ; Siècle 20 ; Sydney ; Sédimentation
Australia ; Eighteenth Century ; Environment ; Estuary ; Harbour ; Historical geography ; Impact ; New South Wales ; Nineteenth Century ; River management ; Sedimentation ; Settlement ; Sydney ; Twentieth Century
This paper traces the history of sedimentation and dredging of the Sydney estuary since that initial clearing in 1788, and discusses the significance of this past shaping of the estuary to current research and environmental management, as well
as to social and economic history. The most detailed dredging records available are for the period 1875-1920. Within the limitations of the data available, annual sediment dredged, annual expenditure, cost per tonne, and areas reclaimed by dredging and filling
Discharge, sediment, and channel characteristics of the Río Panuco, Mexico
Channel geometry ; Fluvial hydrology ; Gulf of Mexico ; Mexico ; Sediment transport ; Stream ; Suspended load ; Tropical zone ; Veracruz
There have been few studies of rivers along the Mexican Gulf Coastal Plain. A. uses fieldwork data and data from Mexican agencies to draw three main conclusions. First, stream flow and suspended sediment reflect summer trade winds and tropical
storms. Second, a profile of change in sediment size in channel lag deposits represents an exception of the usual exponential curve of downstream sediment sizes. Third, the Panuco High anticline represents a neotectonic control on contemporary channel
The glaciolacustrine landform-sediment assemblage at Heinabergsjοkull, Iceland
Landform-sediment assemblages associated with two ice-dammed lakes, one active and one fossil, at Heinabergsjοkull in southeast Iceland are described. These data are vey important for the interpretation of Pleistocene ice-dammed lakes.
Runoff generation and sediment production on unpaved roads, footpaths and agricultural land surfaces in northern Thailand
Cultivated surface ; Model ; Rainfall simulation ; Rill wash ; Road ; Sediment transport ; Soil erosion ; Thailand ; Tropical zone
Rainfall simulation was used to examine runoff generation and sediment transport on roads, paths and 3 types of agricultural fields in Pang Khum Experimental Watershed (PKEW), in mountainous northern Thailand. Because interception of subsurface flow
Amérique du Nord ; Antarctique ; Arctique ; Concept ; Fjord ; Modèle ; Paléo-environnement ; Région polaire ; Sédimentation ; Zone froide
Antarctica ; Arctic Region ; Cold area ; Concept ; Fjord ; Model ; North America ; Palaeo-environment ; Polar region ; Sedimentation
The work reviewed in this paper shows that fiord sediments are being used to assess sedimentary and oceanic processes, as well as glacial, periglacial and geomorphic history, and that they are important proxies for long-term climate and hydrology
. Recommendations for advancing this work include long-term monitoring of conditions in fiords and their drainage basins so that the transfer relations can be more solidly constructed from the proxy of fiord sediment.