Integrated Geographic Information System and Remote Sensing approach to Groundwater Potential modelling in Trans Mara West and Narok West, Narok County, Kenya

Dennis Munai , Justus K. Korir, Vincent Okello, Kenneth Ochieng, Mary Watuka, Edward Mukanda, Judy Muriithi, James Ayacko, Martin Muchangi

Narok County is one of the arid and semi-arid counties in Kenya characterized by variable rainfall patterns and limited surface water resource. Therefore, groundwater is a critical source of water for the sustenance of lives and livelihoods in Narok. This study aimed to model groundwater potential in Narok West and Trans Mara West sub-counties using an integrated approach that combined Geographic Information Systems (GIS), Remote Sensing (RS) and multi-criteria decision analysis. The key inputs into this process include the rainfall, slope, soil type, geology, land use/land cover, drainage density and lineament density. The overarching objective was to identify areas with high groundwater potential. The Analytic Hierarchy Process was employed to assign weights to each input factor based on its relative importance and a weighted overlay analysis that was conducted to generate a groundwater potential map. The results revealed that approximately 43.3% of the study area falls under high to very high groundwater potential zones, primarily in gentle slopes and permeable soil areas, while approximately 56% was classified as low to very low potential, mainly in steep slopes and impermeable regions. These findings provide valuable insights for sustainable groundwater management, enabling policymakers and stakeholders to prioritize areas for groundwater development and conservation. The study also validates the efficacy of GIS and RS technologies in groundwater potential modelling thus offering a replicable framework.  It also highlights the potential of using spatial analysis tools to optimize water resource utilization and management.