zohre ebrahimi khosfi

The phenomenon of dust in recent years has been one of the most important environmental challenges, which has been exacerbated by destructive human activities and has had adverse effects on the environment and human health. Considering that wetlands play an essential role in the balance of water and climate and also prevent the entry of fine dust; The present study was conducted with the aim of analyzing the relationship between the optical depth of aerosol particles (AOD) and the indices of dust-based soil in the area of Horulazim wetland. For this purpose, daily AOD product, MODIS sensor bands and hourly data of dust occurrences related to 3 meteorological stations of Ahvaz, Safi-Abad and Sulaiman masjed were obtained from their supply sources in a period of 18 years (2000-2018). Hourly data recorded in synoptic stations were used to calculate dust storm index (DSI) and MODIS sensor bands were used to extract BTD, BTDI, TIIDI, TDI, Miller and NDDI indices. Linear and non-linear regression methods were used to analyze the relationship between the mentioned indices and AOD. The results of the analysis of the relationship between DSI-AOD showed the very poor performance of this index in the analysis of dust events in all three study stations (R2<0.2). In Ahvaz, Safi Abad and Masjid Sulaiman masjed stations, the maximum value of R2 was observed between AOD-BTDI (0.48), AOD-Miller (0.503) and AOD-BTD (0.50), respectively. These results indicate that, on average, about 50% of the changes in the optical depth of aerosols can be explained using the three indices BTDI, Miller and BTD. Therefore, it is recommended to use these indicators in order to analyze the dust events around Horul Azim lagoon.

The most important structural factor that contributes to desertification is the appearance of salt domes. Due to its solubility and also the effect it can have on the quality of water and soil resources in the surrounding areas, its study is of special importance in agricultural projects and natural resources because it will reduce soil fertility and expand deserts. In this study, it has been tried to determine the quality of surface and groundwater and also to study the factors of geology, morphology, salt dynamics, and tectonic fractures around the Dashti salt dome and its relationship in desertification. The thickness of the salt column in the Dashti salt dome has been estimated at approximately 2,800 meters, and salt glaciers are affected by the topography of the dome (northeastern-southwest) from both sides and laid on the surrounding rocks. For this reason, low sediment is constantly threatened with contamination. Examining the dynamics of the dome, it was found that the balance between the amount of supply and the lack of salt in the desired salt dome is always established and plays an active and permanent role in the expansion of the desert around it. The flow of groundwater in the aquifers of the region is mainly controlled by the permeability of tectonic joints and faults around the dome and confirms the effect of the dome on the salinity of groundwater. Close activity to the surface of the Dashti salt diapir before the orogeny of Zagros is an important and fundamental factor in the destruction of the Kangan anticline soils and the expansion of desertification.