عنوان مقاله [English]
The increasing decline in groundwater reserves in general regions of Iran increase the importance of atmospheric precipitations continuously. This importance is as the role of these precipitations in the agricultural sector, whether dry and irrigated farming and drinking water supply of cities in such ways that each year at the end of the water year are expect to precipitations beginning for filling the reservoirs. This sensitivity is more in the southern half of Iran, and especially in the southwest, which is a region is full of large dams. Collecting the daily precipitation data from a total of 8 synoptic stations in the 30-years period (1987-2016) in southwestern of Iran and separation of precipitations in terms of durability with using programming in MATLAB environment; It provide the selection possibility of 40 precipitation samples to analyze them based on weather maps. Designing of synoptic patterns of humidity flux, atmospheric height and position of jet stream's cores respectively showed that the supplier sources of durable and pervasive precipitations in the fall, are warm waters around Iran including Red Sea, Gulf of Aden, Arabian Sea, Persian Gulf and the Oman Sea, as well as humid flows from regions of central tropical Africa. But during the winter these resources are generally limited to the Red Sea and the Gulf of Aden. Also, the analysis of the position patterns of negative omega cores shows the conditions of more severe inflammation and thermal gradient in the atmospheric column over southwestern of Iran during fall than winter.