Modeling of land subsidence in Shabestar Plain and its relation to groundwater by radar interferometry

Abstract

Shabestar plain has been faced the phenomenon of gradual subsidence in recent years and it is one of the most important plains in East Azerbaijan province in terms of agricultural lands. In this research, the radar interferometry interferogram time series analysis was used in order to predict the subsidence centers of the plain and InSAR data of Sentinel 1as satellite was employed for measuring land subsidence in Shabestar plain with high spatial and temporal resolution in the period 2015-2019 and Adaptive filter was used to modify and refine the phase in each of the images. The result of radar interferometry showed a significant subsidence in the center and west of Shabestar plain with a subsidence rate of 24 cm in this interval. The subsidence level of groundwater level was about 16 m3 measured with Kriging tool. The spatial analysis technique and Moran index of 98% and P value of zero depicted a strong relationship between land subsidence and groundwater level. Unauthorized wells with more exploitation and consequent change of land use and geological conditions in this plain have increased the rate of land subsidence and implementation of the plans for reduction of the risks of land subsidence seems essential.