The objectives of the presented work are on developing methods for extracting hydrologically relevant information from remote sensing data. Recognizing the difficulties in applying former land use and land cover classification systems for hydrological studies of river basins, a land use and land cover classification system for the Sauer River Basin, the Ruhr University Bochum-Land Use and Land Cover Classification System (RUB-LUCS), has been developed for providing distributed information for hydrological modeling, for detection of distributed land use changes and for study of scale problems in land use and land use change detection. Applying this system to Landsat data land use time series have been created for hydrological modeling of effects of man-made changes in the Sauer River Basin. To answer the question, what spatial resolution should be used in characterizing land use and land use changes in hydrological modeling of a mesoscale river basin, a study on scale problems has been conducted. As a result, a hydrological significant resolution is found as 1 km by km.