Land Subsidence Susceptibility Assessment in Semnan plain

Semnan plain is very susceptible to land subsidence and drought, in recent years has greatly increased the occurrence of subsidence. The aim of current research is land subsidence susceptibility assessment using frequency ratio model. At first locations of the land subsidence were specified using Landsat satellite images and field surveys. After classifying conditioning factors maps, the weight of each map was calculated using the frequency ration model. The highest weight was related to water level less than 41 meters, slope less than 2 degrees, topographic wetness index more than 12, agriculture land use type, plan curvature -0.01 to 0.01, profile curvature -0.001 to 0.001, distance less than 1260 meters of road, less than 7000 meters of faults, Quaternary formations and less than 200 meters of drainage network. Finally, by combining the weights, the final subsidence susceptibility map was prepared. The AUC for the frequency ratio model was 0.76 that showed this model is acceptable for land subsidence susceptibility mapping in the Semnan Plain. Land subsidence susceptibility maps produced in this research can be useful and functional tools for regional planners and policy makers for land use planning, resource management, and natural hazard mitigation.