Estacionalidad pluviométrica en Galicia: comportamiento, representatividad espacial y mecanismos asociados

Abstract

Seasonality of rainfall in Galicia (NW Spain) is studied by means of a simple index propossed by Walsh & Lawler (1983). Average values of the index for the 180 meteorological stations studied, indicate that rainfall has distribution patterns ranging from moderate to strong seasonality. Inner areas of the Atlantic Galician Rias, some sectors with cape effect and the valleys of eastern and southeastern rivers are the ones with the gratest degree of seasonality. Nevertheless, a detailed analysis of rainfall series for each meteorological station, reveals that almost all the region has experienced years with rainfall going from weak seasonality to moderate concentration, being strong and extreme concentration unfrequent. Using the frequence of each degree of, seasonality a cluster analysis was performed and corroborated by a discriminant analysis, defining five principal groups. These groups are mapped. Finally, relations betwen seasonality variations and mean anual, winter, spring, summer and fall precipitacions are described. References are also rnade to climatic mechanism implied.