ABSTRACT
In Switzerland, hydrological regimes were classified and regionalized following a study of 95 representative watersheds chosen from the federal and provincial networks using well-defined criteria: the natural flow regime, with series of homogenous measurements over a number of years, a surface area of between 10 and 500 km2, and flows not influenced by large lakes or dams. This study, which was carried out by the Institute of Geography at the University of Bern (Aschwanden and Weingartner, 1985), led to the drawing of a map of natural hydrological regimes with average interannual discharges. Three classes of hydrological regime were distinguished:
• the alpine regime,
• the Jura Plateau regime,
• the southern Alps regime.
