APPLICATION OF PHYSICALLY-BASED EROSION 3D MODEL IN SMALL CATCHMENT

The scope of this study is the application of a new approach for the estimation of potential soil erosion using a physically-based erosion model Erosion 3D for modelling potential erosion in the Myjava River basin, Slovakia. Erosion 3D is a physically-based model for predicting soil erosion by water on agricultural land (Schmidt, 1996). The model is predominantly based on physical principles and it simulates surface runoff, erosion, deposition and the detachment of soil particles for single events, and provides good tool to simulate and quantify soil erosion, but has not been established in Slovakian basins yet. The soil system of Erosion 3D is based on the fourth edition of the soil classification of “Bodenkundliche Kartieranleitung” („KA 4“, AG Boden, 1994). Because of different soil classification it was required in the first step to create an overplot of KA 4 textural system with the USDA textural system used in Slovakia. The model requires three input parameter - relief, precipitation and soil parameters. The first two parameters are easy to obtain but soil input parameters are more complicated mainly for different areas where the model was calibrated and validated. In this study we focused to creation of the soil input data sets for Slovak condition including establishment of Parameter catalogue for every soil input parameters. The catalogue has been configured based on overplotted textural triangle. The Erosion 3D model was applied to a small catchment Tura Luka situated in the Myjava Hill Land which is known for its quick runoff response and related muddy floods. Four scenarios of initial moisture parameter, which is considered as the most sensitive soil input parameter, were applied in fallow and winter wheat. Simulations were done for 100-year design rainfall of 60 minutes duration. The results of potential erosion are well-capable to point to the spatial and temporal variability of the rainfall event with the wide range of the values