The contribution of remote sensing data to distributed hydrologic modeling

Remote sensing data offer spatial information on the state of a large variety of environmental parameters. They determine land surface processes, which are mainly based on the energy balance and the water cycle. The PROMET-family of spatial water balance models was developed. PROMET was given a structure, with allows to maximize the input of remote sensing data. The model-family consists of a SVAT based on the Penman-Monteith equation, a plant-physiological model for the influence of environmental parameters on canopy resistance and a spatial modeller, which provides and organizes input data. Parameters from different remote sensing data sources are presently used (ERS-AMI, LANDSAT, NOAA-AVHRR and METEOSAT) both as input to the model and to validate model results. Model results on the field scale show good agreement with measurements. Spatial data is set up using remote sensing and conventional data sources for the 40.000 km(2) Weser watershed in Northern Germany. Several examples show the utilization of remote sensing data in the model as it is presently possible. From these examples a concept for future utilization scenarios for microwave data in hydrologic models is derived.