The Performance of the Evidence Weighting in GIS for Determining the Effective Factors on the Land Subsidence in Qazvin Plain

Nowadays, intensification of consolidation and land-subsidence are leaded to irreparable damage of financial, environment and human resources. In this research, land subsidence rate was investigated according to the impacts of the main parameters of the aquifer including the geological and hydrodynamic characteristics. Long-term subsidence map was calculated based on SENTINEL-1 satellite data using Differential Interferometry SAR (D-InSAR) method in Qazvin plain from 2015 to 2021. The maximum of land subsidence value of Qazvin Plain was equal to 47 cm during 2015 to 2021 occurred in southwest areas of the Qazvin province. The subsidence spatial distribution was analyzed according to the Weight-of-Evidence (WOE) method to reveal the aquifer characteristic effects. The water-table decline, hydraulic conductivity, slope, land use, fine-grained soil thickness, geology, and bedrock depth were used in WoE method to determine the impact of each parameter on subsidence. The results of WoE, land subsidence hazard potential maps were validated using Receiver Operating Characteristic (ROC) diagram. The most effective land subsidence parameter in the Qazvin plain were the thickness of fine-grained soil with a value of 3.77, while the influence of water level decline was ranked fourth. The land subsidence potential hazard map was able to predict the future land subsidence with an accuracy of 0/87 that indicated the very good prediction. Although water table decline was responsible for the land-subsidence in general, the results of this study indicated that the thickness of fine-grained soil layer was the most effective parameter on the land-subsidence phenomenon.