Groundwater Depletion and Land Subsidence in the Lorca-Totana Region, Southeast Spain: Evidence from EGMS InSAR Analysis

Land subsidence driven by groundwater overextraction poses significant risks to infrastructure, agriculture, and water resource sustainability in semi-arid regions. This study investigates the relationship between groundwater level decline and surface deformation in the Lorca-Totana area, Murcia region, southeast Spain, a zone characterized by intensive irrigated agriculture and chronic aquifer stress.

Using the European Ground Motion Service (EGMS) InSAR dataset, we mapped and quantified surface displacement across the study area, revealing pronounced subsidence zones with mean vertical velocities reaching up to -44.4 mm/year and cumulative displacements exceeding -230 mm over the 2019–2023 observation period. Time series analysis demonstrates a near-linear, continuously accelerating downward trend, indicative of ongoing compaction of unconsolidated alluvial and detrital aquifer materials under sustained piezometric decline.

Groundwater level records from monitored wells in the region corroborate the InSAR-derived deformation signal, showing persistent water table drawdown consistent with the spatial distribution and magnitude of observed subsidence. The strongest deformation anomalies align spatially with areas of highest agricultural water demand and greatest recorded piezometric decline.

These findings highlight the critical feedback between groundwater abstraction and irreversible aquifer compaction in the Guadalentín Valley corridor, with implications for long-term water storage capacity and regional land stability. The integration of EGMS satellite geodesy with in-situ hydrogeological monitoring provides a robust framework for early warning and sustainable groundwater management in similarly stressed semi-arid aquifer systems across the Mediterranean basin.