Detecting Land Subsidence Due to Groundwater Withdrawal in Aliabad Plain, Iran, Using ESA Sentinel-1 Satellite Data

In the present study, ground subsidence in the Aliabad plain (central Iran) was investigated using differential synthetic aperture radar interferometry. The data used for this purpose were Sentinel 1 images acquired during the time range from 24/03/2015 to 8/09/2016. Four interferogram pairs with high coherence were selected to minimize temporal decorrelation. The final analysis was performed in an area where there is sufficient hydrological and geological information. The results revealed that subsidence is a continuous phenomenon in the study area. The vertical displacement rate during the investigated period was estimated to be 178 mm/year. It was also noticed that the subsidence rate in the western part of the plain was higher than in other parts. Moreover, the effects of groundwater level decline, alluvium thickness, and transmissivity on the subsidence level were investigated. Overall, this research provides a correlation between the amount and distribution of land subsidence and effective factors for accurate detection of this phenomenon.