EVALUATION OF GROUNDWATER POTENTIAL ZONE IN IBADAN, SOUTHWESTERN NIGERIA USING GEOSPATIAL TECHNIQUES

摘要

Since water is a fundamental resource for life, understanding its availability would assist governments and other relevant authorities in settlement planning, agriculture and industry. In this study, an attempt was made to delineate possible groundwater potential zones in Ibadan, Southwestern Nigeria using geospatial techniques. Geology, drainage density, soil, slope, land use/land cover, lineament density, geomorphology and rainfall are the thematic layers considered in this study, and they were prepared using NigeriaSat-X, Landsat 8, QuickBird?, SRTM, Google Earth? engine, pedological and geological data. The themes and their individual features were then assigned weights using Idrisi Selva? and online AHP Calculator respectively according to their relative importance in groundwater occurrence and the corresponding normalized weights were obtained based on the Saaty's AHP within some GIS environment. The thematic layers were finally integrated using ArcGIS? version 10.2 to produce the groundwater zonation map of the study area. Thus, four groundwater potential zones were identified and classified as 'Excellent', 'Good', 'Fair', and 'Poor' with 4%, 9%, 21% and 66% coverages respectively. The product will be useful in the development of a sustainable scheme for groundwater exploration, and locating most suitable areas for dry-season farming.