Evaluating Land Subsidence with SAR Interferometric Time Series and Spatial Analyses

Land subsidence is an environmental phenomenon of the gradual or sudden subsidence of the land. The purpose of the present study is to evaluate the land subsidence in Shabestar plain of East Azerbaijan province. Using Small Baseline Subset (SBAS) time series analysis method, the crust surface displacement rate between 2018 and 2021 is investigated. The maximum subsidence is seen in the southern and southeastern parts of the plain with a maximum rate of about 8 cm per year in the direction of the satellite line of sight. Also, using AHP the conditioning factors are weighted and the land subsidence susceptibility (LSS) is modeled using spatial analyses. Thereupon, Shabstar plain was classified into five regions with the LSS: "Very High": 3%, "High": 20%, "Moderate": 25%, "Low": 33% and "Very Low": 19% of the total area of the plain. To verify the accuracy of the subsidence susceptibility model, the displacement map obtained from radar interferometry was utilized, the area under the ROC curve of 86% confirmed the good prediction accuracy of the model. Also, the model was assessed by performing sensitivity analysis for most important conditioning factors. The introduced model can provide useful and reliable information for managers and decision-makers of the region for the effective and timely 'prevention' and 'mitigation' planning with low cost and time.