Integrated assessment of groundwater sustainability using GRACE satellite data and GIS in Debre Markos, Ethiopia

Abstract Groundwater resources in Debre Markos, Ethiopia, are under increasing pressure from urbanization, agricultural expansion, and climate change. This study integrates GRACE satellite data (2002–2017) and GIS-based land use/land cover (LULC) analysis to assess groundwater storage variations, identify contamination risks, and propose sustainable water supply strategies. Results show a persistent decline in groundwater storage and yield, especially in wells surrounded by high-risk land uses. Buffer zone analysis revealed substantial encroachment by agriculture and built-up areas within 300 m protection zones. A spatial buffer analyses around wells in the Wutren and Sentera fields reveal, significant overlap in drawdown zones and inadequate well spacing some as close as 16 m leading to increased mutual interference and aquifer stress. Moreover, risk zones, delineated based on land use encroachment and proximity-based interference, highlight critical areas where agriculture and built-up zones compromise source protection. The study recommends enforcing groundwater protection buffers, optimizing well spacing, regulating land use within critical zones, and expanding remote sensing tools for continuous groundwater monitoring and sustainable water supply planning.