While the outflow from the Alpine rivers is well distributed during the year (9%, 24%, 41% and 26%
respectively for winter, spring, summer and autumn), in the rest of the Country a share between 60 and 90% of
total outflow is concentrated in winter and spring (Rusconi 1995). The National Hydrographic Service (Servizio
Idrografico Nazionale) has issued a map showing that a large part of the South suffers from consecutive periods
without rain of 100-150 days.