Classification of daily rainfall patterns in a Mediterranean area with extreme intensity levels: the Valencia region



The objective of this paper is to identify the spatial distribution patterns of heavy rainfall in the Valencia region, Spain. Rainfall in this area reaches one of the highest intensity levels in the Mediterranean, with daily precipitation values above 800 mm. Although high intensities characterize the region's precipitation, there is a zone situated in the south of the Gulf of Valencia that registers exceptionally high daily precipitation intensities.

Our spatial analysis is based on two different perspectives and methods. In the first, we studied the most important torrential rain events in the period 1971–95 and obtained a classification based on the geographical distribution of the daily precipitation maxima. In the second, we applied statistical techniques to classify the distribution patterns of torrential rain by using principal components analysis and cluster analysis. This analysis was conducted for the 1981–90 period. The results of both methodologies are similar and reflect the main characteristics and sub-types of the spatial distribution of the daily precipitation patterns. These spatial patterns are directly linked to the action of topographic factors in atmospheric situations of humid easterly flows. Copyright © 2002 Royal Meteorological Society.