ASSESSMENT OF LAND DEFORMATION AND LAND USE RELATIONSHIP IN GARMSAR ALLUVIAL FAN USING SENTINEL-1 DATA

Abstract. Differential Synthetic Aperture Radar Interferometry (DInSAR) allows displacements to be detected with millimeter accuracy as well as more advanced methods, such as Persistent Scatterer Interferometry (PSI). Sentinel-1 data have been collected systematically under the COPERNICUS program at a high temporal resolution with global coverage, helping us to build a wide user community and develop miscellaneous SAR-based applications. In the Garmsar alluvial fan, the long-term groundwater overexploitation due to agricultural and urban demands, the utilization of urban space, and erosion have led to land deformation. In this study, the analysis of land subsidence in Garmsar fan was assessed by using the Differential Interferometric Synthetic Aperture Radar (DInSAR) technique based on 20 Sentinel-1 SAR images from January 2019 to June 2022. Distinct variations of land subsidence were found in the study regions however, it can be seen in most land use types. The maximum annual land subsidence rate has occurred in urban areas with an average rate of 95.2 mm/year from 2019 to 2022. Analysis showed that serious land subsidence mainly occurred in the following land use types: urban areas, agricultural lands, and bare lands.