Monthly runoff of the river Reuss: mean per decade

The Swiss Alps are one of the main sources of drinking water in Central Europe. The natural water regime of a region is characterised by the variability in precipitation, evaporation and runoff in space (i.e. in the regions) and time. The way society deals with the water flowing from the Alpine valleys has important consequences, not only for ecology (maintenance of biodiversity), but also for the economy (electricity production, industry, shipping, irrigation, drinking water supply) and politics (water treaties covering cross-frontier river systems).
Runoff is formed both at the surface and within the ground from liquid precipitation and melted snow and ice. The variability in distribution of natural runoff generation in space and time is characterised by the interaction between the climatic values (primarily precipitation, air temperature and solar irradiation) and the local features of the terrain (topography, geology, soil properties, vegetation and land use).