Statistical analysis of weather-type runoff phenomena in an Alpine environment

In order to get a better insight into the role of hydrologic regime components in an Alpine environment, runoff characteristics were analysed in relation to atmospheric circulation types over a 23-yr. period. For this purpose, atmospheric circulation types were classified into hydrologically relevant classes of weather types using Schüepp's classification which was developed for the European Alpine region. It is found that the magnitude of runoff during each particular class of weather types is largely governed by autocorrelation (related to the characteristic times of the systems active during preceding classes and thus related to the preceding weather types) and by antecedent conditions, rather than by the weather types themselves. The influence of a weather class displays a distinct dependency of the time elapsed since the start of the particular class. This influence does not become manifest until after a 2–3-day period on the average.