Increases in precipitation in winter and spring could translate into higher river flows, w'ith eventually more frequent and severe flood events. Alternatively, lower precipitation in summer is likely to reduce river flows, with potential risks of temporary w'ater shortages during critical phases of crop grow th. Such shifts in the seasonality of river flows are, for example, projected in most parts of Europe, except for most northern and southern regions. Figure 1.4 presents an illustrative example of projected changes in river flows in the case of four European rivers: the Rhone (Switzerland and France), the Danube (Central Europe), the Indalsaelven (Sweden) and the Guadiana (Spain). Water stored as glacial ice is a region’s hydrologic insurance (e.g. during the 2003 European drought, the flow in the Danube River was three times higher than the long-term average flow). It is believed that glacial mass has been affected by long-term climate changes, with a trend towards glacier retreat, especially since the 1980s.