Use of remote sensing and GIS techniques for groundwater exploration in the basement complex terrain of Ado-Ekiti, SW Nigeria

Abstract

Integrated investigations involving remote sensing and GIS have been conducted with the objective of achieving optimal results in sustainable groundwater development in Ado-Ekiti, south-western Nigeria. The hard rock terrain in the region presents challenges in groundwater exploration. Landsat imageries were used for landuse/landcover mapping and lineament analysis for groundwater prospecting. Shuttle Radar Topographic Mission Digital Elevation Model was used for drainage network extraction, slope and geomorphological analysis. Thematic maps were generated, analysed in terms of hydrogeological importance and reclassified for integration using appropriate software. The groundwater potential maps generated were validated against the existing groundwater yield data. The light vegetation and bare soil area cover was 110.9 km2, with the rock outcrops covering a total area of 14.9 km2. Hydrogeomorphic units delineated included hills, pediments, pediplains, alluvium and valley fills. The lineaments showed predominantly NNW–SSE, ENE–WSW and NNE–SSW orientations and subsidiary NW–SE and W–E trends. Application of geospatial techniques has been recognized. The methodology provides improvements in the understanding of the hydrogeological characteristics of the basement terrain. These will aid planning and management of groundwater resources in the crystalline basement terrain.