GIS-Based Site Suitability Analysis for Solid Waste Landfill Location in Kaduna State

The selection of appropriate landfill sites is a critical environmental planning challenge for rapidly growing Nigerian cities generating increasing volumes of municipal solid waste. This study applies GIS-based multi-criteria evaluation to identify suitable landfill locations in Kaduna State, a key urban centre in the North West zone. Spatial criteria considered include distance from residential areas, road accessibility, proximity to water bodies and ecological reserves, soil permeability, slope gradient, and wind direction. Data layers are derived from Sentinel-2 imagery, SRTM digital elevation models, topographic maps, and the Kaduna State Environmental Protection Authority inventory. Analytical Hierarchy Process weighting is applied to assign relative importance to each criterion, and a weighted overlay analysis is conducted in ArcGIS to generate a composite suitability map classified into five zones from highly suitable to unsuitable. Results indicate that suitable sites are concentrated in the eastern and northern peripheries of Kaduna Metropolis, away from population centres and sensitive water catchments. The study eliminates over seventy percent of the state's land area as unsuitable on environmental and social grounds. Three optimal candidate sites are identified and ranked, with detailed buffer zone specifications provided for each. The findings are intended to guide the Kaduna State Environmental Protection Authority in planning compliant waste management infrastructure. Keywords: GIS, landfill suitability, multi-criteria evaluation, Kaduna, solid waste management.