Monitoring and zoning sultry phenomena in the southern provinces of Iran

Southern provinces of the country in the Persian Gulf and Oman Sea are under the damp of this undesirable phenomenon in the major part of the year, due to the enormous potential in various fields of industry, transport, trade, warehousing, agriculture, services and tourism in recent decades.The present study examined the occurrence of humid condition in the southern provinces of Iran. The purposes of this study were to determine the start and end time and duration of humid , determine The extent of sultry , monthly zoning of sultry phenomenon by means of geographical Information system ( GIS ) and finally , determining areas with same sultry by cluster analysis ( by distance ).To perform the processes of study , the data related to temperature, RH , saturated vapor pressure at 12 ( UTC ) related to 54 synoptic and climatology stations in Southern provinces of the country include Khuzestan , Boshehr , Hormozgan , Sis tan va Baluchistan were gathered from Meteorological Organization for a period of 12 years ( 1997 – 2008 ) . The model used for calculation of humid extremity was Lancaster – Kerstin model. The calculation of sultry for southern provinces showed that the worst sultry condition was related to southern parts of province and its intensity decreased in north parts. Among under study provinces, Hormozgan was worst in sultry occurrence point of view, due to the more southern latitude and Khuzestan province had the lowest level of humid. The concentration of high pressure beside the torrid in the early of hot period and its stability lead to the aggregation of sultry phenomenon in this part of country. The under study province have had a better sultry condition only in last mouth of fall and early two months of winter due to the regression of high pressure to southern latitudes , so that the sultry phenomenon have not been seen in December, January , and February. The result of cluster analysis showed that the first cluster had a highest level of sultry is southern part of Sis tan and Hormozgan. The level of sultry in second cluster include central regions was middle and the third cluster had weak sultry occurrence.

کلیدواژه ها:

Sultry ، Southern provinces ، zoning ، cluster analysis GIS