The field of hydrology deals with the processes comprising the water cycle and provides the foundation for water resources management. The tasks range from data collection and statistical processing (e.g. precipitation, evapotranspiration or runoff) to the mathematical description and simulation of hydrological processes.

Various tasks in water resources management (e.g. water supply, irrigation, drainage or flood protection) rely on hydrological data. Therefore, the assurance of sufficient data quality is a major concern. Besides the development of novel measurement devices and principles, the validation of observed variables is a fundumental and current research topic.

Hydrological modelling aims to replicate a catchment response to a given forcing (e.g. precipitation) with the use of mathematical process descriptions. This allows to evaluate the impact of constructive measures on the water cycle (e.g. induced by land-use changes) or to predict the occurrence and magnitude of flood events. Besides typlical fluvial flooding events, the simulation and forecast of local flooding induced by extreme rainfall events (pluvial flooding), both in urban and rural areas, is of increasing importance. Along with the design of water resources management practices, the evaluation of climate change impacts on the water cycle plays an increasingly important role. 

Flood disasters affect large numbers of people around the world each year and have severe social and economic impacts as well as ecological consequences. Large-scale, but also locally limited, floods also occur repeatedly in the European and Alpine regions, sometimes causing considerable damage.

Floods are, in principle, natural phenomena that can more or less regularly affect all river catchment areas in the world and thus also fulfill essential functions of the natural ecosystem. Due to the increased expansion of human settlement areas and the associated space requirements, the rivers are given increasingly less space under flood conditions. There is a lack of retention areas and floods are now mainly perceived because of their negative and not because of their positive effects.

Through active flood protection, such as extensive regulatory measures, certain river sections can be protected from flooding, but in most cases this only means shifting the phenomenon at the expense of areas further downstream. Knowledge of flood risk is a multidisciplinary task that requires an understanding of the processes and mechanisms, spatial and temporal forecasting, vulnerability assessment and the monitoring and modeling of the effects, including with regard to environmental and climate change.