ANALYSIS OF DEM RESOLUTION DEPENDENCE ON A HYDROLOGICAL AND SEDIMENT MODEL FOR AN UNGAUGED BASIN IN PERU

Abstract

 Prediction of erosion and sedimentation in ungauged basins at the northern coast of Peru is a critical issue to mitigate flood disasters. In this paper we developed a spatially-distributed integrated hydrological and sediment model based on kinematic wave equations to carry out sediment transport simulations using spatially distributed satellite rainfall data. We compared our simulation results against the collected field sediment samples from the 2016 flood at Tumbes River, Peru. The results show that our integrated model performs with robust convergence at 500 m and 1,000 m resolutions and successfully reproduced a hysteresis discharge-sediment concentration relationship according to historical time series analysis. Afterwards, the influence of topographic resolution on sediment parameters was assessed. We identified the most sensitive parameters and its effects on sediment concentration and sediment yield output. For a comprehensive analysis of DEM resolution dependence, we discuss how settling velocity and particle diameter drive the results convergence.