High and low flows and associated floods and droughts are natural phenomena caused by meteorological anomalies and modified by various, but similar catchment processes. The scope of this general session on hydrological extremes is to learn from the similarities and differences of basic ideas and concepts for both extremes, from generating physical processes to modelling approaches.

The main objectives of this session are:
- to foster the understanding of the main governing processes of hydrological extremes, including spatial and temporal patterns of floods and droughts,
- to discuss modeling approaches and concepts on how to include process understanding in predictive models,
- to discuss the potential of historical data for predicting hydrological extremes,
- to present methods and practical applications for estimating and/or predicting floods, droughts and low flows at a regional scale as well as regional methods for making predictions at the local scale,
- to address the potential impact of global change, including climate and land use changes, on hydrological extremes,
- to profit from the similarity and differences of modeling concepts for both extremes.

The scope of the session includes both general methodological contributions and case studies of hydrological extremes in different regions. All methodological contributions will ideally discuss the benefits of the method for the challenges of hydrological extremes.