Integrating Geospatial Mapping and Stakeholders' Perception on Sustainable Flood Solutions in a Typical Coastal Megacity of Nigeria: A SWOT-AHP Approach

Opeyemi Aniramu^*Oluwagbenga Orimmogunje

• Obafemi Awolowo University, Ife, Nigeria

The study identified urban flood-prone areas, surface inundation mapping, and prioritize strategic flood solutions using integrated approach. Satellite imagery of Digital Elevation Model, Sentinel-2, and spatial rainfall data were utilized for spatial vulnerability mapping in Lagos State. In addition, questionnaire were administered to participants on 40 elements outlined in the SWOT survey instrumentation, and responses were analyzed. Findings revealed high flood vulnerability in the study area, particularly the densely populated metropolitan areas with inadequate drainage infrastructures. Rainfall patterns during the JJA and SON peaks were linked to flood frequency and high surface inundation, highlighting the need for early warning systems and drainage improvements. The SWOT-AHP revealed flood strategies across four thematic pillars: Environment (0.45), Legal and Institutional (0.22), Socio-economic (0.16), and Urban Engineering (0.16). Strategic alternatives were ranked based on global weight values and categorized into shortterm strategies focused on critical infrastructure and evacuation planning. Mid-term priorities included green infrastructure and smart monitoring systems, while long-term strategies emphasized sustainable urban planning and regulatory enforcement. Findings underscore more integrated policy implementation, community engagement, and improved investment on adaptive infrastructure to reduce flood risk. The structured decision-support tool suggested a proactive, sustainable, and inclusive flood resilience strategies for stakeholders.