Assessment of the accuracy of digital elevation models for modeling soil erosion (by the example of a small catchment area in the Kursk Region)

Abstract

Results of evaluation of sediment redistribution in a small cultivated catchment based on the basis of 10 different digital elevation models (DEM) (unmanned aerial vehicle (UAV) surveys, digitized topographic maps, ALOS, SRTM, ASTER, etc.) are presented. Potential soil erosion was calculated using the WATEM/SEDEM based on the RUSLE algorithm. The relevance of the work is due to the lack of comparative assessments of the impact of DEMs on the calculated values of erosion and sedimentation using the erosion modelling. Studies have revealed that the results of mathematical modeling largely depend on the resolution of the DEM. In particular, a tendency to increase the areas of sedimentation zones with an increase in the size of the DEM cell is noted. The average annual estimates of sediment budget are quite close in the case of using a UAV DEM, ALOS and SRTM with a close size of the DEM cell (from 20 to 38 meters). The smallest average annual soil losses from water erosion were obtained using the most detailed DEM (cell size 1 and 5 m). The ASTER model should not be used for calculations of soil erosion on a catchment scale due to the significant distortion of the relief.