Toward Landscape-Based Groundwater Recharge in Arid Regions: A Case Study of Karachi, Pakistan

Rapid urbanization and climate change are the driving forces behind changing the urban landscape and affecting natural resources and the environment, particularly in the megacities of arid regions. Many of these cities face an acute water crisis leading to over-exploitation of groundwater resources. This over-exploitation has led to the depletion of aquifers, land infertility, saline intrusion, land subsidence, and harm to hydrological ecosystems. Globally, numerous studies have documented the potential of groundwater recharge (GWR) using GIS and remote sensing techniques. However, its practical application in a landscape context for sustainable urban and regional development is underexplored. In this study, we developed the landscape-based GWR concept by conducting a case study of Karachi city (Pakistan). We took physical landscape (surface and sub-surface) features and groundwater recharge potential as a base for design and planning to improve groundwater recharge and urban landscape. Moreover, we highlighted the added values of this approach besides recharging the depleted ground hydrological conditions and improving the urban landscape condition (i.e., social–ecological inclusiveness, sustainable future development, and interdisciplinary collaboration). The results indicated a negative impact of urbanization on groundwater recharge, especially in the alluvial zones and river valleys, underscoring the need for a spatial approach to safeguard GWR and guide development. Through this study, we propose that landscape-based GWR can be one of the potential solutions not only for the critical water crisis faced by rapidly urbanizing arid megacities but also for improving the overall quality of life and urban landscape. Furthermore, this holistic approach toward groundwater recharge can guide future urban development patterns, preservation of high groundwater recharge potential sites, and evolution toward sustainable development in arid regions where groundwater is the most significant yet vulnerable resource.