The use of ERS SAR data derived soil moisture distributions for SVAT-model validation

Soil moisture plays a key role in hydrological, meteorological, and agricultural land surface processes. It determines to a large degree evapotranspiration, surface runoff, infiltration, percolation to the ground water and also the vegetation development. Latent and sensible heat fluxes associated with evapotranspiration provide energy for climate dynamics. For modeling the hydrological cycle the knowledge of both spatial distribution and temporal dynamics of soil moisture is crucial but also complicated due to the high spatial and temporal variability. Active radar remote sensing data has the potential to monitor soil moisture since radar backscatter intensity depends upon the soil moisture in the top soil layer. Another means to calculate soil moisture patterns is the use of spatial distributed models. In this paper the results of spatial soil moisture model runs are compared with remotely sensed soil moisture distributions