Plate 6.6 Water Balance of River Basins in the 20th Century

The climatic changes observed since the middle of the 19th century include a rise in temperature which has led to greater melting of glaciers and higher levels of evaporation. Precipitation patterns can also change. Changes in land-use such as more intensive farming or increased afforestation also result in increased evaporation.Long measurement series for the elements that make up the water balance thus show on the one hand the water resources available in a catchment and, on the other, how the water balance has possibly changed owing to the influences mentioned above.