Le but de cette étude est de montrer et d'établir les bénéfices et les limites du géoradar dans un terrain proglaciaire. En particulier, cette technique aide à différencier la structure interne de sédiments gelés faiblement triés.
Cosmos ; Flood ; Fluvial processes ; Geology ; Geomorphology ; River bed ; Sedimentation
A unique clustering of layered streamlined forms in Athabasca Valles is hypothesized to reflect a significant hydraulic event. The forms, interpreted as sedimentary, are attributed to extensive sediment deposition during ponding
and then streamlining of this sediment behind flow obstacles during ponded water outflow. These streamlined forms are analogous to those found in depositional basins and other loci of ponding in terrestrial catastrophic flood landscapes. Likewise, the streamlined forms
Sediment sources and sediment transport by rill flow and interrill flow on a semi-arid piedmont slope, southern Arizona
Arid land;Arid environment ; Arizona ; Precipitation ; Rainfall simulation ; Rill wash;Runoff ; Sediment budget ; Sediment transport ; Slope ; Soil erosion ; Splash ; United States
The purpose of this paper is to compare the characteristics of sediment transport by rill flow with that by interrill flow on the same runoff plot in southern Arizona. A sediment budget for the rill system is established in order to : a) estimate
the relative contribution of sediment from the rill and interrill areas, and b) evaluate the response of the rill system to storms of various durations.
This study aims to quantify flood-based sediment yields in 2 highly active headwater catchments in the upper Isábena River : Villacardi and Cabecera. The results are compared with the sediment delivery from a zero-order badland catchment
and the sediment yield at the outlet of the basin, upstream of the reservoir. A novel regression aproach is applied that allows the interpolation of intermittent measurements of suspended sediment concentrations, computes confidence intervals for these estimates
Downstream variation in bed sediment size along the East Carpathian rivers : evidence of the role of sediment sources
Carpathian Mountains ; Drainage network ; Grain size distribution ; River bed ; Romania ; Sediment budget ; Sediment load ; Sedimentology ; Stream ; Suspended load
This paper intends to approach the phenomena of river-bed material variability inside a network of rivers from the drainage basin of Siret as a link between sediment sources and their sediment delivery. The AA. will focus on the spatial variability
sediment through the Carpathian tributaries, while the second mode, of the sands, is local.
Many fjords situated in lowland areas of resistant bedrock are characterized by a comparatively low fluvial sediment flux and are often dominated by wave processes. Several such fjords in Eastern Canada are used as examples to develop a generalized
sediment distribution model. Storm waves resuspend fine-grained sediment in water depths of tens of metres and produce near bottom turbid water zones within basins. Fine sands and silt settle out rapidly, leading to the deposition of graded beds
on the basin floors. Residual sand and gravel accumulate on the near-shore platforms while silt and mud prograde over or are advected beyond basin slopes, burying older basin-fill sediment.
Streamflow and sediment transport from mountain watersheds of the Chao Phraya basin, northern Thailand : a reconnaissance study
Catchment area;Watershed ; Hydrology ; Land use ; Mountain ; Rill wash;Runoff ; Sediment transport ; Thailand
The A. disputes the hypothesis that land-use practices have altered the hydrologic regime of these basins or have contributed to an increased sediment load in the rivers. - (DWG)
Revue des techniques utilisées dans la reconstitution des pH dans la stratigraphie des sédiments lacustres. Cas d'étude en Suède, Ecosse et aux Etats-Unis.
Glacial landform sediment associations are reported and the implications for glacigenic depositional sequences are discussed for areas that have experienced proglacial thrusting.
Impact of deposition on the enrichment of organic carbon in eroded sediment
Field experiment ; Organic materials ; Sediment transport ; Sedimentary ; Soil erosion ; Topography ; Vegetation ; Watershed
Examen de l'enrichissement en carbone organique dans les sédiments transportés en relation avec les dépôts induits par la topographie et la végétation.
Sources of suspended and deposited sediment in a Broadland river
Increasing rates of bank erosion and sediment deposition have been reported from the Norfolk Broads since the early 19th century. The major sources of both suspended and deposited sediment in the rivers and Broads is quantified using sediment
mineralogy, identified by X-ray diffraction. This indicates that higher proportions of bank derived sediment are present in suspension in the waterway during the summer months, due primarily to bank erosion by motor craft. Dated sediment cores show how
the sources of inorganic sediment have changed over time. Whilst in the past upland catchment sources dominated, at present material is mainly derived from river bank material.
Quantification de haute précision de l'apport de sédiments du versant à la rivière. Résultats préliminaires du transport de la charge de rivière dans la première saison après l'événement de terrain et comparaison avec l'introduction de sédiments de
leurs principales sources. Etablissement d'un bilan sédimentaire préliminaire pour l'étude de la mouille du lit. Mise en lumière de l'influence de l'apport de sédiments supérieurs sur le transport de sédiments vers l'aval et l'hydrologie.
The AA. report on bedload transport observations using piezoelectric bedload impact sensors (PBIS), an indirect method of estimating the volume of bedload transport of coarse sediment. Sediment transport at the Erlenbach stream has been continuously
monitored with a PBIS array starting in 1986. Sediment volumes for individual flood events estimated with the PBIS method are in agreement with volumes estimated using an independent empirical method based on the effective runoff volume of water, the peak
water discharge, and the critical discharge for the onset of sediment transport.
Sediment transport in a highly regulated fluvial system during two consecutive floods (lower Ebro River, NE Iberian Peninsula)
Dam ; Ebro ; Environmental degradation ; Flood ; Fluvial erosion ; Hydraulic works ; Mediterranean area ; Sediment load ; Sediment transport ; Spain ; Stream ; Suspended load
The transfer of sediment through a highly regulated large fluvial system (lower Ebro River) was analysed during 2 consecutive floods by means of sediment sampling. Suspended sediment and bedload transport were measured upstream and downstream
of large reservoirs. These results illustrate the magnitude of the sediment deficit in the lower Ebro River. They can be use for the design and implementation of restoration programmes in large, highly degraded fluvial ecosystems, especially
Ireland. Sediment released by an erosional front is forming beach ridges, spits, and transient linkages. Transfer of sediment is significant for barrier form and control of coastal change. Linking of adjacent drumlins affects dispersal of material within
Moraine formation in northwestern Ontario : product of subglacial fluvial and glaciolacustrine sedimentation
Selon les AA. les sédiments de ces moraines représentent des dépôts de sédimentation rapide associés à de grandes crues qui ont provoqué une instabilité passagère du système hydrographique et (ou) un déferlement antérieur à la sédimentation frontale
L'étude de 3 carottes de sédiments, jusqu'à 135 cm de longueur, montre des variations nettes dans les caractéristiques des sédiments et dans les assemblages des diatomées à travers l'Holocène. Discussion et interprétation. Reconstitution des phases
The suspended sediment discharge of the River Euphrates at Haditha, Iraq : an assessment of the potential for establishing sediment rating curves
The results presented indicate that in this case, suspended sediment rating curves established using infrequent samples (2 - 4 samples per month) can be employed to provide estimates of annual loads and of mean annual loads which are within 20
Sedimentation characteristics of natural dust in the wake of symmetrical hills
Résultats d'une recherche réalisée dans un tunnel éolien pour savoir si à l'aval d'obstacles topographiques, il existe dans le modèle de sédimentation de matériaux fins et poussiéreux (loess), des fluctuations comparables avec les ''traînées de
tourbillons de Karman''. L'expérience n'indique aucune traînée de sédimentation observable, bien qu'une sédimentation secondaire maximum se présente dans une zone immédiatement à l'aval du versant de la colline situé sous le vent.