Spatial Analysis of Jiroft Plain Subsidence Using the Coherence Pixel Technique (CPT)

The phenomenon of land subsidence is one of the most important environmental hazards that have affected many plains of the country today. Jiroft Plain located in Kerman Province is also one of the areas where subsidence effects are evident. In this research, besides analyzing the spatial subsidence of Jiroft Plain and determining the extent and trend of its spread over a period of time, the effective factors in this phenomenon were investigated. For this purpose, the Sentinel-1 radar images related to the years of 2014-2022 were used. The Coherence Pixel Technique (CPT) was utilized to map the affected areas and determine the subsidence rate. The results of this method showed that the subsidence rate in Jiroft Plain had increased from 11 cm in 2014 to 13 cm in 2022. In addition, its area had increased during this period and the expansion trend had moved towards the northern areas of the plain. To analyze the causative factors of this phenomenon, in addition to studying the changes in the groundwater level of the plain and its relationship with subsidence, the roles of faults and soil thickness in creating or intensifying this phenomenon were investigated. The results showed that in addition to the uncontrolled abstraction from the aquifer, the subsidence of Jiroft Plain was affected by Sabzevaran Fault, while subsidence intensity was higher in the areas with higher soil thickness.