Evaluating the changes in the water body of Salehiyeh Wetland caused by the construction of drainage

Salehiyeh Wetland, located in Alborz and Qazvin provinces, is one of the wetlands that has dried up in recent years and has become a center for dust production. The aim of this study is to evaluate the trend of changes in moisture in Salehiyeh Wetland and investigate the role of drainage channels in the drying of the wetland bed. To achieve this goal, the MNDWI index was calculated using Landsat 5, 7, 8, and 9 satellite images from 1990 to 2023. The construction of drainage channels has caused some changes in the wetland catchment area. Therefore, the non-parametric Mann-Kendall test was performed before and after the construction of drainage channels in two previous and current catchment areas. Also, the wind data from synoptic stations around the wetland were analyzed by drawing the storm rose diagram. The results of the study show that the overall trend of changes in moisture in Salehiyeh Wetland during the study period has been decreasing, and the MNDWI index has been negative in most years due to the drought prevailing in the region. Due to this, the phenomenon of dust and the problems resulting from it have spread to the surrounding cities. Therefore, measures need to be taken to preserve and manage the water resources of Salehiyeh Wetland and prevent its drying, such as optimizing water consumption, preventing the construction of inappropriate drainage channels, and using various solutions such as implementation of mechanical windbreak to reduce the sand and dust storm.