Landfill site suitability mapping for rational development planning: a GIS-based multi-criteria evaluation in Edo State, Nigeria

Use of sanitary landfill in waste management may involve complex processes but has proven to be sustainable and effective in mitigating environmental degradation when the site is properly located. Despite this innovation, waste mismanagement compounded by alarming population growth, increasing urbanization and industrialization had raised much environmental concern in Edo State, Nigeria. Therefore, the present study integrated ten most common and applicable selection criteria with a view to identifying suitable landfill sites with environmental and socio-economic benefits for proper waste management, rational land use and sustainable development planning in four Local Government Areas in the State. The selection criteria used are surface water bodies, land use, land slope, depth to groundwater, geology, lineament, soil media, built-up area, road network and airport location. The Analytic hierarchy process technique was used to compute pair-wise comparison matrix for determining criteria weights while the weighted linear combination method was employed in combining the criteria weights. ArcMap 10.2 overlaid the ten thematic maps to generate a landfill site suitability map. The results of the study showed significant land use dynamics and drastically increasing built-up areas. This rapid urbanization had overtaken all the existing dumpsites which failed to meet adopted standards in the metropolis thereby rendering their locations inappropriate in today's urban setting. Hence, the dumpsites constituted potential environmental menaces with socio-economic and health implications. This study has identified eight potential sites for sanitary landfill which could guide decision makers in formulating effective policies towards sustainable environment, urban planning and water resources development in the area.