DAM SUITABILITY ANALYSIS USING AN INTEGRATED GEOSPATIAL ANALYTICS, AND MULTI-CRITERIA DECISION ANALYSIS-ANALYTICAL HIERARCHICAL PROCESS (MCDA-AHP) ANALYSIS FOR OGBESE RIVER BASIN

In order to evaluate the suitability of dam sites within the Ogbese River Catchment in Ekiti State, this study uses an integrated geospatial and Multi-Criteria Decision Analysis (MCDA) framework with the Analytic Hierarchy Process (AHP). Using satellite imagery, Digital Elevation Models (DEMs), and geospatial databases, six basic thematic layers; geological characteristics, soil classification, topographic elevation, slope gradient, drainage density, and land use/land cover were painstakingly created and standardized. To appropriately reflect the relative importance of each criterion, weights were assigned using AHP pairwise comparisons. A dam suitability map that classified the basin into highly suitable, moderately suitable, marginally suitable, and unsuitable zones was produced by the weighted overlay analysis carried out in ArcGIS. According to the findings, only 5.84% of the catchment is considered suitable for dam construction, with 1.22% (3.62 km2) being the most suitable and 4.62% (13.68 km2) being other suitable areas. The two main influencing factors were determined to be soil type (21%) and geological stability (29%). The Federal Polytechnic Ado-Ekiti and the surrounding communities will benefit from the strategically placed sites, which offer opportunities for improved, water supply, and agricultural productivity. In addition to providing a replicable framework for dam site selection in similar catchments across Nigeria, the conclusions emphasize the importance of combining geospatial technologies with MCDA for evidence-based infrastructure planning.