Human exploitation of aquifers and its impacts on crustal stress changes and increased seismicity in Iranian plains

Abstract

Extensive and continuous groundwater extraction in Iran over the past decade has led to a marked decline in groundwater levels and persistent land subsidence. These hydro-geomechanical transformations can influence seismic response through two mechanisms: reduction of pore pressure, thereby decreasing effective stress on slip surfaces, and poroelastic stresses generated by large-scale aquifer unloading, which redistribute the crustal stress field from basin to regional scales. The aim of this paper is to empirically and model-based assess the “groundwater withdrawal–stress change–seismicity” relationship in several representative plains of the country. To this end, multi-source, real, and scale-consistent datasets are compiled and integrated: Sentinel-1 InSAR time-series for deriving subsidence rates and bowls; piezometric well logs and exploitation data for estimating groundwater drawdown and extraction intensity; and seismic catalogs from national and international networks for calculating event rates, focal depth, β-value, and temporal non-stationarity. Through spatial/temporal co-location of datasets, time-series analysis, multivariate regression, and controlling for seasonal hydrological loading, the anthropogenic component of seismic changes is quantified. The novelty of this study lies in the simultaneous integration of InSAR, hydrogeological, and seismological datasets for 2015–2025, testing drawdown thresholds linked to significant shifts in seismicity parameters, and proposing management scenarios based on extraction thresholds to reduce induced seismic risk. The results are expected to clarify spatio-temporal patterns connecting groundwater depletion and subsidence with seismic parameter changes and to provide a basis for water resource policy, land-use planning, and seismic risk reduction in densely populated plains of Iran.