Multi-criteria approach to assess groundwater potential: a case study of Baringo County, Kenya

Abstract

Abstract In this study, the groundwater potential zones in Baringo County (Kenya) were identified using an integrated approach of Remote Sensing-Geographic Information System (RS-GIS) and Analytical Hierarchy Process (AHP) techniques, and thematic layers of rainfall, slope, lithology, soil type, land use, drainage density and lineament density. The data were validated using borehole yield and fluoride data obtained from boreholes in the area. Using RS-GIS-based methods to identify potential groundwater zones is more convenient and less expensive compared with the conventional methods. Rainfall, lithology, soils and land use/land cover were found to be the most significant factors influencing groundwater with weighted values of 31, 24, 18 and 10% respectively. The very good, good and poor potential zones covered 0.39, 65.33 and 34.27% area coverage of the study area respectively. Low yield boreholes were found in the poor groundwater potential zones and vice versa. Moderate yield boreholes were found in the good groundwater potential zone. The majority of the boreholes with acceptable fluoride concentration was found in the good groundwater potential zones, while those with high fluoride concentration levels were found in the poor groundwater potential zone. Generally, from this study, it can be concluded that remote sensing and GIS in conjunction with AHP are important tools in monitoring and evaluating groundwater resource potential areas.