Evaluation of environmental hazards of Tasuj area based on multivariate decision method

The study area is Tasuj region, in East Azarbayjan Province, which consists of the mountainous and Tasuj plain. The purpose of this study is identification the areas with high potential for subsidence, earthquake and landslide in the Tasuj region, based on the factors affecting their occurrence and using the hierarchical analysis process (AHP) method. In this study, the effect of groundwater drawdown and the risk of subsidence due to it were evaluated. The average amount of water table drawdown in the study area was calculated about 6 meters and areas with high subsidence risk were identified. For the mentioned hazard zoning, 15 criteria, such as water table, water table drawdown, slope, aspect, distance of stream, land use, elevation, lithology, distance of fault, earthquake depth, fault length, distance of epicenter, earthquake magnitude, distance of road and rainfall were used. According to the results of this study, the criteria of water table, distance of faults and lithology, respectively, have the greatest effect on the risk of subsidence, earthquake and the potential for landslide occurrence. Also, most of the areas associated with high risk of subsidence, earthquake and landslide are located in the central and southern parts of the plain, eastern and northern parts of the region and mountainous and steep areas in the north and east of the region, respectively. Therefore, by studying the resulting zoning maps and identifying high-risk points in the basin, their harmful effects on natural resources and other parts can be reduced.