Investigation of Iran Vulnerability Trend to Desertification with approach of climate change

In this paper for study of amount of Vulnerability of Iran to Desertification is used of bioclimatic index of UNEP (United Nation Environment Programme). First Annual temperature average and total of annual precipitation from 45 synoptic meteorological stations for a 30 years period (19762005) has been collected the Meteorological Organization of Iran. Then UNEP index are computed for all of studied stations. In final using Mann-Kendall graphical statistical test was investigated UNEP changes trend in Iran. On the basis of UNEP index is observed that most of areas of Iran have arid and semi-arid climates. With respect to desertification intensity class, these two kinds of climates have classes of severe and very severe. After those two kinds of climates, ultra arid, dry sub-humid, very humid and sub humid climates have the most area in Iran, respectively. Results of Mann-Kendall test show that in three stations of Birjand, Tabriz and Mashhad, UNEP index changes trend have sign of tendency from semi-arid climate to arid climate. Changes trend at two stations of Oroomieh and Khoy have tendency from dry sub-humid climate to semi-arid climate. Changes trend at station of Sanandaj have sign of replacement between semi-humid climate with semi-arid climate and station of Yazd have tendency to ultra-arid from arid climate. But station of Zabol at north of Sistan and Baluchistan province, have been alone station that has had positive trend, that is its changes trend have been from ultra-arid climate to arid climate. Changes trend of all of these stations at level of alpha = 0.05 are significant.