Assessment of the impact of the accuracy of the DMR on the calculation of soil erosion using the USLE and USLE-2D models

Abstract

Slovakia has recorded a potentially significant increase in water erosion, especially after consolidating the plots of hundreds of hectares of agricultural area with monocultures of marketable crops. This is also due to large blocks of land being created on sloping sites. Due to its simplicity, the Universal Soil Loss Equation (USLE) is most commonly used to calculate potential soil erosion. This study compares the classical USLE and the USLE-2D methods, which consider the combined spatially variable slope length and steepness. The slope length is replaced in USLE-2D by the contributing area based on a raster digital model relief model. Data from Tulčík cadastre in east Slovakia demonstrates the results of water erosion on 26 plots used as agricultural areas. As expected, differences were found, which were further analysed concerning slope lengths and steepness. Comparing the grid size (1, 10 and 20 m) for the USLE-2D model showed that more significant differences were obtained for plots with a smaller area and a higher slope. It was confirmed that at a lower pixel resolution, the results are overestimated.