The Role of Topography in Intensification of Precipitations in the south and South-west of Iran((Case Study:3 December 2015))

In this study, 10 precipitation systems were selected as prototypes between October and June 2016-2015. Then, 70 stations from the country's satellite stations were divided into four general groups in the south, southwest and center of Iran. The daily precipitation of the stations was extracted from each platform. To determine the patterns of precipitation occurrence in the Sudan low pressure region, atmospheric data from 1000 to 500 HPa are extracted from the NCEP / NCAR site and in the GRADS the maps of these ten systems were mapped. One of the most important systems that provide rainfalls in the Middle East is Sudan low pressure Lashkari (1996). The results showed that the systems entering Iran and the Middle East from the mentioned Sudan low pressure have a special mechanism. These systems have strong convection mechanisms because of having a thermal nature in their source and receiving a huge amount of moisture from the surrounding warm seas. They form deep boiling clouds and cause intensive and torrential showers when accompanied by deep waves in layers 700 and 850 HPa. Therefore, the cloud always forms in a convective way, and the height does not play a significant role in the intensification of its precipitations. In other words, it does not have a significant role by itself, at least in the windward slopes of the Zagros Mountains. The intensity of precipitation is, therefore, sometimes higher in the plains compared to the mountain summits. It seems heights play a more effective role in elevations above 1,500 meters in both windward and leeward slopes. However, in the Alborz mountain chain, there is a very clear and impressive correlation between precipitation and height because of re-creation of systems