The research of this group focusses on catchment-scale hydrological processes and river basin water management. With respect to hydrology special emphasis is put on the development of physically-based and conceptual models of surface and subsurface flow processes to examine the hydrological system and its component processes and to study the effects of climate change, land-use change and other human influences on the water and solute balance of catchments. Spatial information technology, such as remote sensing and geographic information systems, are essential tools in this field. To improve model calibration and validation procedures and to improve on-line and off-line simulation performance advanced (geo-)statistical data mining techniques are being studied and applied. Central in this research are mathematical tools, such as neural networks, non-linear optimization procedures, disaggregation techniques and date assimilation. The group uses these models and techniques to study floods and droughts in river basins. Another main theme of research is river hydraulics and morphology as an element of hydrological modeling and to support sustainable river and land management planning. Theoretical developments are tested in a fully-equiped hydraulics laboratory where model studies can be performed. The research of the group on integrated water resources management combines knowledge about catchment-scale hydrological processes with additional information (rules and regulation, stake holders interests) to improve policy and decision making at the national and international level. Specifically, methodologies are developed to handle uncertain information from field observations, model simulation results, and targetted objectives. This research is coordinated by thetemporary chair on Integrated Watermanagement.