A distributed approach for sediment yield evaluation in Alpine regions

A distributed model for the simulation of the water budget and prediction of the sediment yield in Alpine catchments is presented. The strongly variable landscape typical of Alpine regions was schematically represented through a raster of square cells. The hydrological phenomena were modelled at this cell scale. A well-gauged Alpine catchment was selected to validate the model. A catchment digital terrain model (DTM) was created through an automatic treatment of the catchment contour lines, selected stream lines, and soil and vegetation cover maps. Water and sediment routing to the catchment outlet was performed by integrating simplified versions of the equations of continuity and motion for both water and sediment. The governing equations were integrated and calibrated on a monthly time scale by using available field data on rainfall, discharge and sediment yield at the catchment outlet. The numerical simulations showed that the proposed mathematical model was able to adequately simulate the water and sediment budgets of the test catchment on a yearly and a monthly scale. © 1997 Elsevier Science B.V.