The potential of Sentinel-IA interferometric SAR data in monitoring of surface subsidence caused by overdrafting groundwater in agricultural areas

摘要

The use of Interferometric Synthetic Aperture Radar (InSAR) data has become known as an important technique for monitoring and measuring land surface deformations caused by groundwater level fluctuations. In this study, a region from the closed Konya agricultural basin is selected to infer the spatial and temporal distributions of the ground deformations using SAR images acquired by the comparatively new satellite Sentinel-1A of the European Space Agency (ESA). With the purpose of revealing Sentinel-1A satellite sensors potential we employ 18 months of periodical data obtained of 43 SAR scenes on the ascending T87 and 45 SAR scenes on the descending T167 satellite tracks. We apply GMTSAR, an open source InSAR processing system that uses Generic Mapping Tools (GMT). InSAR time series have been calculated using the SBAS method. The preliminary results obtained indicate the efficiency of Sentinel-1A alone over a comparatively short period of time in monitoring land surface subsidence. Even though the calculations and processing were performed in presence of relatively noisy data, the results obtained are consistent and in agreement regardless of the flight direction of the satellite. The estimated deformation rate obtained from both ascending and descending tracks is about 2 (+/-1) cm/yr.