The connectivity between soil erosion and sediment entrapment in reservoirs

Rivers are characterized by their water flow regime and sediment transport. Sediments are crucial for channel morphology, water quality, providing habitat for aquatic organisms and, finally, for sustaining deltas. Rivers are, however, fragmented by dams and will face an additional building boom due to actions to mitigate climate change (with hydropower) and water scarcity. Reservoir siltation is a serious challenge for reservoir management but also entails downstream morphological impacts. However, sediment entrapment is an often neglected element in reservoir planning and environmental assessment. The aim of this study thus is to give an overview on the links between soil erosion and sediment entrapment in reservoirs, its degree on a global scale (reservoirs lose annually 1% of their capacity), the driving factors that influence associated processes and the different approaches for reservoir management to reduce siltation and its impacts downstream.