Principal Component Analysis of precipitation and rainfall regionalization in Spain

Summary A T-mode Principal Component Analysis (PCA) based on a network including 68 pluviometric gauges and their 12 mean monthly amounts of rainfall is attempted in order to describe the main patterns governing precipitation in Spain. The procedure is applied to a 12 × 12 intermonth covariance matrix; the unrotated components and two additional solutions deduced after varimax and oblimin rotations are presented and discussed. In all cases component scores are computed and their spatial distribution is discussed. Two regionalizations of Spanish rainfall are then obtained and compared in terms of group homogeneity. There follows a discussion concerning the main pluviometric characteristics of each region deduced from the best division.With 7 Figures