SBAS-InSAR Analysis of ALOS-2 and Sentinel-1 SAR Data for Monitoring Land Subsidence in the East Azerbaijan Province of Iran

Abstract. Iran, as a semi-arid and arid country, has faced significant challenges in water resource management in recent decades. The over-extraction of groundwater, driven by improper agricultural development, has significantly contributed to land subsidence. Therefore, identifying and quantifying ground subsidence in major plains is crucial for mitigating potential hazards. Recently, the Interferometric Synthetic Aperture Radar (InSAR) technique has been widely used to measure land surface deformations, providing accurate monitoring of ground movement with high spatial and temporal coverage. This study utilized time-series SBAS analysis with L-band (PALSAR-2) and C-band (Sentinel-1) SAR data to examine long-term ground displacements in East Azerbaijan Province. The results indicated significant subsidence in two major regions, the Tabriz and Shabestar plains. The cumulative vertical displacement in the study area from 2015 to 2023 reached -587.7 mm, with maximum subsidence rates of -73.67 mm/year based on ALOS-2 data. A comparison of SBAS results between L-band PALSAR-2 and C-band Sentinel-1 data showed a high level of agreement. For Sentinel-1, the cumulative vertical displacement from 2017 to 2023 was -374.7 mm, with maximum subsidence rates of -59.97 mm/year.