Geospatial techniques for groundwater potential zones delineation in a coastal municipality, Ghana

Abstract

Water is an indispensable resource without which human survival is impossible. Many households in the Komenda-Edina-Eguafo-Abrem (KEEA) Municipal, Ghana, rely on pipe-borne sources for drinking and domestic purposes. However, over the years, supply has been inconsistent due to operational bottlenecks bedeviling the water distribution agencies. Against this backdrop, this paper argues that tapping into groundwater resources could provide practical solutions to the water challenges facing the area. However, little is known about the spatial distribution of this precious resource as a solution to the uneven water distribution in the district. Consequently, the main objective of this study is to map groundwater potential zones (GWPZ) in the study area utilizing geospatial techniques. To accurately assess the groundwater condition of the area, eight pertinent factors that influence groundwater recharge were selected. Weights were assigned to these factors using the Analytic Hierarchy Process and superimposed in a geographic information systems environment to generate the GWPZ. The resultant map was classified into five zones namely very poor, poor, good, very good, and excellent. Results demonstrate that, overall, a larger proportion (almost 36%) of the study area was within poor groundwater zones. However, other areas (27%) were identified as very good locations for groundwater prospecting. Areas close to the coast were mostly found within poor zones. Using functional boreholes as a proxy for validation confirmed that 76.5% of the boreholes are within suitable sites for groundwater discovery. These results are significant for policy-making, sustainable planning, and management of water resources by stakeholders.

Keywords

• Groundwater
• Groundwater Potential Zone Mapping
• Analytic Hierarchy Process
• Remote sensing
• GIS
• Ghana