Modeling Of Groundwater Potential Using GIS And MultiCriteria Decision Analysis Around Kwara State, Southwestern Nigeria.

Abstract

A geoelectric investigation of groundwater prospect around Kwara State, within the basement complex of southwestern Nigeria was carried out with a view to providing information on the geoelectric characteristic of the subsurface sequence, bedrock topography, subsurface structural features and their hydrogeologic significance, in order to identify aquifer units and determine possible areas for groundwater potential zones. The study involved the use of Schlumberger vertical electrical sounding data at seventy three (73) stations. Groundwater potential map was also generated from the integration of geoelectric parameterss using multi-criteria evaluation techniques. The results obtained from this study illustrate that the integration of the data handling method proposed in this study with geophysical technique can provide inexpensive, reliable and accurate method for characterizing, assessing and evaluating an aquifer system. The method can also be adopted in other geophysical studies, where challenges of making accurate and reliable decision from set of multiple criteria are faced. Groundwater potential map was also generated from the integration of these maps using multi-criteria evaluation techniques. The study area has been classified into low, moderate, high groundwater potential zones and the results from borehole data and hand pump well data across the entire study area were used to validate the accuracy of the groundwater potential map. From the results obtained, it could be concluded that the study area is an area of low groundwater potential.