The impact of changes in climate and land use on soil erosion, transport and deposition of suspended sediment in the River Rhine

The objective of this study was to estimate the potential effects of changes in climate and land use on the mobilization of fine sediment and the net transport of wash load from the upstream basin to the lower Rhine delta. For this purpose, a suite of geographical information system-embedded models was developed that simulates the production, and transport of wash load through the drainage network and deposition on floodplains along the lower river reaches. The model results indicate that if climate changes in accordance with the UKHI climate-change scenario, in combination with land use changes, erosion rates will increase in the Alps and decrease in the German part of the basin. Averaged over the entire basin, erosion will increase by about 12%. However, due to inefficient sediment delivery, increasing erosion in the Alps will have little effect on the sediment load further downstream. In the delta area, sediment loads are expected to decrease by 13%. When changes in river discharge are accounted for, it appears that, although very high discharges are expected to occur more frequently, sedimentation on floodplains tends to decrease. This is caused mainly by reduced sediment loads at discharges during which the floodplains are just inundated and trapping efficiencies are high. Copyright (C) 2003 John Wiley Sons, Ltd.