Triangulation Approach for Mapping Groundwater Suitability Zones in Coastal Areas Around Lagos, Nigeria. Using Multi-Criteria Decision-Making Technique

Water quality in Lagos's coastal area is prone to constant seawater intrusion due its proximity the Atlantic Ocean. Seawater aquifer a major challenge human survival and therefore needs urgent attention deficiency groundwater quality. This study applies integrated techniques map suitability zone (GSZ) around Lagos for sustainable development. The objectives were achieved by preparing eight different thematic layers that influence viz; drainage density, geology, geomorphology, lineament rainfall, longitudinal conductance, slope, transverse resistance. Weighting assignment, normalization and, pair-wise comparison of maps done using Saaty’s Analytical Hierarchical Process (AHP) model before being through geographical information system (GIS) spatial analyst with weight overlay generate overall map. result reveals 7% research location has very low suitability, 32.2% low, 47.8% moderate, 13% high suitability. Thus, was validated via Electrical conductivity (EC) total dissolved solids (TDS) good correlation. proven efficacy integrating surface subsurface data effectively mapping (GSZ).