Simulation of water fluxes using different methods for estimating soil parameters

The model system SIMULAT was applied to compute the water dynamics of a loam site from the Krummbach catchment and a sand site from the Eisenbach catchment, two research catchments in north Germany. The simulation period was three years. In this study two procedures of obtaining soil hydraulic properties were tested with regard to the applicability in simulation models. Simulations using measured retention curves are compared with results where the retention curves were estimated by a pedo-transfer function. Because measured retention data suggest a bimodal pore size distribution at the loam site which can not be described using standard approaches, additional simulations were carried out using bimodal retention curves.