Determinants of urban settlements' vulnerability to flood hazard in Ibadan Metropolis, Nigeria

Research Doctorate - Doctor of Philosophy (PhD)Humankind has witnessed an unprecedented increase in the frequency and scale of flood disasters in the last three decades. Floods have become a serious concern worldwide because of the fatalities they cause as well as the immense economic and ecological damage that ensues. While recognising these risks are not the product of physical systems alone, it is unlikely that they can be efficiently minimised by focusing on hazards (technical factors) alone without considering the social aspects of those affected. A review of previous studies has revealed few deals with the social perspectives of the root causes of flood vulnerability in Nigeria. This thesis contributes to the body of knowledge on this topic by introducing an Urban Political Ecology (UPE) conceptual lens to examine the root causes of inconsistent flood vulnerability in the metropolitan city of Ibadan, Nigeria. The UPE analytical framework offers a new dimension to flood vulnerability studies, uncovering inequalities and providing insight into how residents in three urban communities (Bere, Mokola and Basorun) experience different risks. The study proffers answers to five research questions: (i) Who is vulnerable to flood hazards in the study areas? (ii) How vulnerable are they to flood hazards in the three selected urban communities? (iii) What factors influence urban residents’ flood vulnerability in the three zones? (iv) How do these factors create different levels of flood vulnerability in the three zones? (v) What are the ways vulnerability can be minimised, and how can resilience to flood hazards be improved? The study embraced pragmatic worldview, employing a mixed-methods approach. Primary data was collected from a survey of households. The survey assessed, measured, and established social groups’ level of vulnerability through indicators, and statistical analysis of population data. Participatory focus groups with households were conducted to understand better how selected indicators and factors interacted to influence flood vulnerability and produce different vulnerabilities within the zones. In addition, experts were interviewed to consolidate earlier findings by providing insight into the underlying causes of flood vulnerability through the lens of UPE. This further demonstrated the roles of socio-political forces and institutional structures in creating unequal flood vulnerability. The quantitative Statistical Package for the Social Sciences (SPSS) and Nvivo 10 qualitative software were used to facilitate data analysis. The findings of the study (i) show that typical urban residents in the study areas are vulnerable to flood hazards because of their unique exposure, lack of capacity to deal with flood events and lack of potential to recover from them. Furthermore, they have limited access to social and political resources. (ii) provide evidence of differential vulnerabilities to flooding in the three study sites. Bere community, a low-income and high-density urban settlement is the most vulnerable to flood risk among all the three study areas in the Ibadan metropolis. (iii) identify that communities display spatial and differential evidence of social inequities, political marginalisation and environmental injustice. The research demonstrates that the political, sociocultural, demographic, and economic factors play a critical role in shaping the irregular potential for flood vulnerability in the city. (iv) affirm that flood vulnerability is socially constructed. The study demonstrated how different households’ profiles including assets (income, tenure security, housing quality), sociobehavioural characteristics and institutional structures determined the levels of households’ and communities’ vulnerability to flooding. (v) show that steps to reduce flood vulnerability and build resilience should not focus solely on technical solutions. An understanding of an individual’s socioeconomic aspects, households and diverse communities’ perceptions and experience is also required. It is evident that families’ and communities’ assets profiles (including their political, socioeconomic, demographic, behavioural and environmental characteristics) determine their flood vulnerability. The flood impacts observed were mostly irregular. While the study demonstrates that political and institutional decisions benefit some residents, the lack of government commitment to build resilient societies is the root cause of flood vulnerability. Continuous investment in structural measures (such as stronger levees and other technical solutions) alone cannot reduce flood vulnerability. Non-structural strategies, and equity and justice in resource management are also required