A study of the Homogenous Rainfall Zones of Iran Using Cluster Analysis Based on TRMM Satellite Data

This study aims to evaluate Spatio-temporal distribution of rainfall through cluster analysis based on Tropical Rainfall Measuring Mission (TRMM) in Iran. To this purpose, the daily-gridded rainfall data were derived for the 1998-2013 period. Then, the seasonal and annual time scale cluster analysis was performed on TRMM-derived rainfall data. The results identified 14 clusters in the annual rainfall. As a high- rainfall zone, Guilan has an average rainfall of 1068 mm per year while Sistan, as a low-rainfall area, has an average rainfall of 106.8 mm annually. Furthermore, the seasonal rainfall distribution indicates high-rainfall zones in Guilan and Mazandaran provinces in spring, summer, and autumn while the areas in the southern range of Alborz Mountain and Persian Gulf are clustered as low-rainfall zone. The rainfall distribution in Iran is seasonal, and the following provinces are among the high-rainfall zones in winter: Kohgiluyeh and Boyer Ahmad, Chaharmahal and Bakhtiari, Khuzestan, and highlands of Lorestan. The low-rainfall areas also include Sistan and Baluchistan, Yazd, and Semnan.