Plain Subsidence Monitoring based on SNAP2STAMPS Automated Algorithm by Radar Interferometry (PSI) Method (Case study: Marand Plain)

Global climate changes and population growth have increased the need to exploit underground water resources. The phenomenon of land subsidence as a result of groundwater extraction and water depletion is one of the environmental hazards that threatens societies all over the world. In this research, for the first time, Sentinel-1 radar satellite images were used by the SNAP2StaMPS to automate the process of processing and analyzing the subsidence in Marand Plain. In recent years, the uneven development of agricultural lands and the excessive extraction of underground water in the Marand plain in East Azerbaijan province have caused landslides on the surface of this plain. In this study, an automatic interferometric processing algorithm between SNAP and StaMPS was used to determine the displacement rate in the direction of the satellite line of sight. The results of the PSI interferometry technique were performed on 133 images of the Sentinel-1 satellite in the descending orbit of the Sentinel-1 satellite. Based on the obtained results, the annual land displacement rate for Marand plain in 2016, 2017, 2018, 2019, and 2020 was -13.7, -12, -2.15, -12.3 and -13.1 cm respectively. In order to validate the results, the amount of subsidence resulting from the interferometric processing was compared with the amount of groundwater level drop in the study area, using the unit hydrograph analysis method. The results showed that the amount of water level drop and the results of hydrograph analysis of observation wells in the region are consistent with the results of time series maps obtained from interferometry. Therefore, the automatic method presented in this study can be used for monitoring land subsidence.