Land subsidence is a major geomorphological hazard in arid and semi-arid regions, primarily driven by excessive groundwater extraction. In such areas, declining water tables can cause irreversible compaction of fine-grained sediments, reduced aquifer storage capacity, and damage to critical infrastructure. This study aims to monitor subsidence rates in the Damghan aquifer and analyze their relationship with groundwater level decline using satellite imagery and ground-based data. The study area covers approximately 1,522 km² of the Damghan aquifer in Semnan Province, characterized by a layered and heterogeneous alluvial structure. Data sources include Sentinel-1A radar images (2017–2021), groundwater level records from 38 observation wells (2012–2019), and drilling logs from 13 production wells. Radar data were processed using SNAP software, and spatial-temporal analyses were conducted in ArcGIS and GMS environments. Results indicate that groundwater levels in central and southeastern parts of the aquifer have declined by over 7 meters, with an average annual drop of 0.46 meters. Radar interferometry maps revealed subsidence rates of up to 32 cm in these zones. Soil texture and saturated layer thickness analyses showed that areas with high clay and silt content are more sensitive to water level decline and subsidence. Zoning results indicate that 44% of the aquifer surface is affected, with the highest rates observed in zones with alluvial thickness exceeding 230 meters. Field evidence—including surface fissures, well damage, sinkholes, and structural failures—highlights the practical implications of this phenomenon. Findings underscore the urgent need for continuous groundwater monitoring and targeted management to mitigate infrastructure risks and ensure environmental sustainability.
