Spatial Urban Land Suitability Assessment for Risk-Sensitive Planning in A Rapidly Urbanising Nigerian City: A GIS–AHP–MCDA Approach for Ilorin, Nigeria

Abstract

Rapid urban expansion creates complex demands for land allocation, infrastructure provision and environmental management, particularly across heterogeneous urban environments. This study developed a GIS-based Multi-Criteria Geospatial Evaluation (MCGE) framework to assess urban land suitability in Ilorin Metropolis, Nigeria. Remote sensing and GIS techniques were integrated with the Analytical Hierarchy Process (AHP) and weighted overlay using seven criteria: slope, land use/land cover (LULC), Normalised Difference Vegetation Index (NDVI), land surface temperature (LST), population density, proximity to roads, and proximity to water bodies. Sentinel-2 imagery was classified to derive the LULC layer, achieving an overall accuracy of 92.5% and a Kappa coefficient of 0.89. The resulting LULC distribution comprised rangeland (65.01%), built-up land (17.46%), cropland (10.53%) and water-related features (6.98%). AHP assigned the highest weights to NDVI (24.72%), LULC (19.19%) and population density (16.22%), while the consistency ratio of 0.055 indicated acceptable judgement consistency. Weighted overlay generated an Urban Land Suitability Index classified into five levels. Moderate suitability was dominant (35%), followed by Low and High (20% each), Very Low (15%) and Very High (10%). High and Very High suitability were concentrated around the urban core and major infrastructure corridors, whereas lower suitability occurred mainly near river corridors, steeper terrain and thermally stressed areas. The findings show the utility of integrating remote sensing, GIS and AHP as a transparent decision-support framework for guiding sustainable urban development and land-use planning.