The synergetic use of airborne sensors to determine parameters for SVAT-modelling

Methods of remote sensing to detect land surface parameters provide the opportunity to retrieve quantitative and up-to-date input parameters for distributed hydrological models. Conventional areal information on plant growth and topography are usually taken from literature or are provided by public services, neither being sufficient to represent short term variations in time and space nor to determine small scale heterogenities in water-balance calculations. In order to simulate the hydrological process in detail, a large variety of model parameters have to be provided at a high accuracy. Among these, the topographical parameters, such as altitude, terrain slope and aspect and its derivations play an important roˆle, since they have a major impact on physical processes, such as the availability of radiation at any point in the observed catchment. Vegetation parameters, such as biomass, leaf area index or plant height are crucial for the description of plant phenology and hence its stomatal activity governing the transpiration amount. This study investigates the potential of a digital terrain model taken from the AeroSensing-1 single-pass interferometric SAR-sensor and spatially distributed information on plant development derived from the Digital Airborne Imaging Spectrometer (DAIS 7915). These data sources are synergetically applied within a hydrological framework, in terms of the Soil-Vegetation-Atmosphere-Transfer model PROMET