Modeling sediment delivery in arid upland basins

Abstract

An upland sediment delivery model was developed for estimating the sediment delivery rates at the rising, peak and recession stages of a flow hydrograph in an arid upland basin. The model uses a steady state sediment continuity equation and a first order reaction model for deposition since the initial potential sediment load is always greater than the overland flow transport capacity, calculated by the Yalin method, in the arid regions. The model predicts the sediment delivery rates within +/-10% accuracy at each hydrograph stage through calibration using slope and flow length combinations at the basin outlet. It is sensitive to unit width discharge and the Manning's roughness coefficient. A simplified version of the Yalin equation when used with the model accurately approximates the sediment delivery rates in the arid upland basins.