Evaluating the impact of irrigation on groundwater resources using remote sensing: a case study for Saudi Arabia

Saudi Arabia faces major challenges in managing its scarce freshwater resources, particularly as agricultural expansion increases pressure on groundwater. Remote sensing offers an effective alternative where ground data are limited, yet a clear gap remains in linking crop-specific evapotranspiration (ET) to groundwater depletion. This study examines three key date-producing regions, Madinah (western Saudi Arabia), Al Qassim (central Saudi Arabia), and Hofuf (eastern Saudi Arabia), by integrating SEBAL-derived ET (validated against field measurements) with GRACE-based groundwater storage (GWS) changes from 2013 to 2022. The combined analysis reveals a strong correspondence between ET rates and GWS declines, demonstrating the potential of ET as an indicator of groundwater abstraction in arid agriculture. An economic model further quantifies the financial value of groundwater embodied in date production, estimating indirect groundwater exports of 0.4–0.9 USD m⁻³. These findings support region-specific irrigation optimization and provide practical guidance for improving groundwater sustainability in water-limited environments.