Assessing the effectiveness of nature-based solutions and the role of Community-Based solutions in mitigating flood disasters

Flooding is still a major urban problem that is exacerbated by climate change, rapid urbanization, inadequate urban planning, and poor governance systems. Studies have revealed that Nature-Based Solutions (NbS) and Community-Based Disaster Risk Reduction (CBDRR) have become cutting-edge approaches to enhancing flood resilience, especially in highly vulnerable areas such as Lagos. The purpose of this study is to evaluate the effectiveness of NbS and CBDRR strategies in reducing flood disasters and increasing adaptive capacity. A mixed-method approach was employed, and the study collected data from 384 residents in flood-prone areas in both Lagos and Ibadan, Nigeria, who were given structured questionnaires to gather quantitative data. Also, key informant interviews were conducted to collect data from local officials, community leaders, city planners, and NGO leaders.The results of the study highlighted that although Lagos has more widely adopted NbS practices, such as retention basins and tree planting, both cities continue to struggle with a lack of institutional coordination and infrastructure. In Lagos, where government frameworks better support CBDRR methods like flood awareness programs and drainage clearing, community involvement was more substantial. Statistics revealed that there are connections between institutional support, public knowledge, and the perceived efficacy of both CBDRR and NbS; however, obstacles such as low technical capacity, lax enforcement, and insufficient funding efforts still exist. The study suggests specific initiatives for each city based on fundamental assistance in the areas of policy development, enhancing institutional cooperation, and long-term investment to upkeep green infrastructure. Ultimately, the study concluded that a synergistic combination of ecological innovation, community agency, and multi-level governance is needed to achieve urban flood resilience in these cities.