The assessment of groundwater reserves, quality, and balance in Quang Nam region, Vietnam: using MIKE BASIN and MODFLOW models

Abstract This comprehensive study examines the groundwater reserves and quality within the Quang Nam region, Vietnam, utilising the integrated MIKE BASIN and MODFLOW models. The research systematically analyses the coastal and key economic zones, covering 259,039 hectares, including urban and rural districts. The study delineates the region’s hydrogeology, revealing a significant volume of groundwater reserves with a static water level, suggesting robust aquifer systems, particularly in the Dien Ban and Thang Binh districts. Furthermore, hydrogeochemical analysis assessed groundwater quality, indicating suitability for agriculture, which accounts for 81% of the region’s water demand and other uses. The study’s novelty lies in its dual approach of quantifying groundwater reserves and evaluating their quality, addressing a critical regional water resource management gap. The findings present an optimistic scenario for the current and future sustainability of water resources, with the calculated groundwater reserves demonstrating ample capacity to support the varied needs of the region. This research establishes a foundational understanding of Quang Nam’s hydrological system. It provides strategic insights for sustainable water management in response to socio-economic development and climate change projections up to 2030. Climate projections for Quảng Nam province under RCP 4.5 and RCP 8.5 scenarios indicate significant increases in rainfall, temperature, sea level rise, and saltwater intrusion, highlighting the critical need for adaptive strategies to protect local ecosystems and communities from these escalating climate threats.