The Use of GIS for Identifying Optimum Landfill Sites in Osogbo, Southwestern, Nigeria

The amount of waste disposed off globally has significantly increased due to increase in population and change in consumer habits. Million tons of organic waste are disposed of globally through incineration, land applications, landfill, and other methods. Selecting appropriate places for waste landfills is a challenging task for planners, especially in states with dense populations such as Osogbo due to land scarcity, land prices, and increased solid waste generation. Therefore, this study aimed to identify the optimal suitable areas for the solid waste landfill for proper waste management in the study area. In this work, a multi-criteria decision-making approach combining GIS and the Fuzzy Logic technique for landfill suitability site evaluation was used. Six factors are involved in the selection process namely soil, drainage, land use/land cover, built-up areas, road network, and slope. Using the weighted overlay analysis tool in the GIS environment, the results of the MCDM assigned to each criterion show that five potential sites in this study were suitable for the construction of a potential landfill, of which two are located in the most suitable zone and three are located in the unsuitable zone. It was concluded that the results presented on the final aggregation maps demonstrate the significance of selecting the appropriate criteria weights for the environmental and economic set of standards.