An analysis of regional and intra-annual precipitation variability over Iran using multivariate statistical methods

The temporal and spatial precipitation regime of Iran was analysed using mu ltivariate analyses of monthly mean precipitation records for 71 stations. A Principal Component Analysis was applied to the correlation matrix in ord er to describe the intra-annual variations of precipitation. The Principal Component scores were mapped to visualize the spatial structure of the thre e derived precipitation regimes. By applying an agglomerative clustering (W ARD) of the three Principal Component scores, five homogeneous spatial clus ters, representing five precipitation regions, were developed. The intra-an nual types of precipitation distribution, shown by the five clusters, are d escribed and discussed.