چكيده لاتين
Recently, drought, heat wave and dust have become more annoying. These risks have increased in the southwest of Iran. In order to analyze the dust in this area and the factors affecting it, environmental factors such as precipitation, temperature fluctuations, surface temperature, water levels, vegetation cover, soil temperature, atmospheric humidity and synoptic patterns for selected dry and wet years. The assessment has been placed. The research method used in this research is a combination of telemetry and statistical-synoptic analysis. In synoptic studies, the environmental to circulation method is used to study the relationship between dust events and synoptic patterns. Terrestrial data includes precipitation data, minimum and maximum temperature, soil temperature and number of dusty days, and atmospheric data includes network data of sea level pressure, geopotential height, omega, spiral, air temperature, orbital and meridional wind. which was downloaded from the National Center for Environmental Prediction (NCEP) website. Remote sensing data includes Landsat satellite data and SMOS satellite data. According to the findings of this research, environmental degradation in vegetation (r = -0.818), water (r = -0.801) and rainfall (r = -0.721) which ultimately lead to a significant increase in dust will be The results show that the increase in surface temperature is the result of the changes in the land cover in the region. The synoptic survey shows that in the hot seasons, the atmospheric instabilities that have led to the creation of dust are the result of the operation of the ground surface and local thermal systems. On selected dusty days of these seasons, omega values are positive in the upper levels of the atmosphere (at 500 hectopascals), which is a sign of atmospheric stability. In the hot season, at this level, the Azores dominates the region and prevents the ascent and instability of the atmosphere at this level. But the omega values are negative at the level of 850 and 950 and indicate the existence of instability, but in the cold seasons of the year, the input systems cause dust in the region due to the lack of sufficient humidity. In these seasons, omega values are also negative at the level of 500 hectopascals, but this instability has led to dust instead of precipitation because there was not enough moisture. During hot seasons, low pressure dominates the surface of the region, and the results show that these low pressures are stronger in dry years. The reason for this can be seen in the type of land surface cover that in dry years there is less vegetation and water and the land surface has a higher temperature due to more heating of the bare surface, which leads to the strengthening of low pressure systems. The results indicate a significant increase in dusty days in dry years (43 days in 2019 as a wet year, and 117 days in 2017 (dry)).
