Geo-Spatial Assessment of Urban Sprawl in Ibadan, Oyo State, Nigeria

This study quantifies and maps urban sprawl in Ibadan Metropolis (core five LGAs) between 2010 and 2025, and projects near-term growth using cloud-based geospatial methods. Using Landsat Collection 2 Level-2 surface reflectance imagery (30 m) on Google Earth Engine, we combined spectral indices (NDVI, NDBI), Random Forest classification, Landscape Expansion Index typology (infill, edge expansion, leapfrog), and CA–Markov/RF projection to analyze land cover change, vegetation health, directional growth, and future sprawl risk. Results show built-up area more than doubled from 2010 to 2025, with the strongest expansion concentrated along transport corridors and in peri-urban LGAs (Akinyele, Egbeda, Oluyole, Ona Ara, Lagelu). Mean NDVI declined markedly in peri-urban zones, indicating substantial vegetation loss and increased flood and heat vulnerability. Edge expansion dominated new growth (~60%), with infill and leapfrog representing the remainder. Predictive models indicate continued outward expansion through 2030–2035 under a business-as-usual scenario, threatening infrastructure, ecosystem services, and peri-urban agriculture. The study delivers a reproducible GEE-based framework for continuous urban monitoring and produces actionable spatial intelligence for planners and policymakers. Findings support targeted growth boundaries, greenbelt conservation, and evidence-driven land management aligned with SDG 11 (Sustainable Cities and Communities).