The balance between water demand and availability has reached a critical level in many areas of Europe, resulting from over-abstraction and prolonged periods of low rainfall or drought (EEA Report No 2/2009). It is therefore necessary on one hand to develop reliable indexes for the identification of the beginning and ending points of drought periods and, on the other hand, to enhance models and techniques to forecast the evolution of the most influential hydro-meteorological variables during water scarcity periods, also taking into account potential effects due to climatic changes, with predicted increases in the frequency and severity of droughts conditions.

The session will address modelling techniques, both of the data-driven and of the physically-based type, aimed at monitoring and forecasting, over medium to long time horizons, the hydro-meteorological variables that describe and govern a situation of water scarcity, and in
particular: precipitation, streamflow, snow cover, soil moisture and groundwater. Accurate and timely information on these variables under water scarcity conditions is crucial for the implementation of sustainable water resources management and possible adaptation measures to the foreseen climatic changes.

Particularly welcome are applications and real-world case studies in Mediterranean areas and other regions subject to significant water stress, where the importance of long-term water availability forecasts is likely to be further exacerbated in the future.