Analytical Assessment of Optimum Landfill Site Selection Using Multi-Criteria Evaluation in Enugu State

The siting of sanitary landfills involves complex trade-offs between geological suitability, proximity to population centres, transportation access, environmental sensitivity, and community acceptability, requiring systematic multi-criteria evaluation to identify optimal locations. This study analytically assesses optimum landfill site selection for Enugu State, South East Nigeria, using a GIS-based multi-criteria evaluation framework. A GIS-based multi-criteria decision analysis (MCDA) methodology was adopted, integrating ten siting criteria: distance from water bodies, depth to groundwater, soil permeability, bedrock depth, distance from settlements, access road proximity, land use type, slope gradient, distance from airports, and land cost. Criteria were weighted using the Analytic Hierarchy Process based on responses from 30 environmental engineers and planners. A suitability index map was generated for Enugu State's 17 LGAs using weighted overlay analysis in ArcGIS. The top three site candidates identified by the model were field-verified for physical conditions and community reception. Results indicate that suitable landfill site areas represent 8.4 percent of the state's total land area. The three highest-suitability sites are located in Nkanu West, Igbo-Eze South, and Udenu LGAs. All three candidates have adequate buffer distances from settlements and satisfactory hydrogeological conditions. The study fills a significant evidence gap in Enugu State solid waste management planning and the suitability map provides a decision support tool for the state Ministry of Environment.

Keywords: landfill siting, multi-criteria evaluation, GIS analysis, Enugu State, solid waste management