FLOOD VULNERABILITY AND DETERMINANTS OF EXPOSURE IN INFORMAL SETTLEMENTS OF ABA URBAN, NIGERIA

Flood vulnerability in rapidly urbanizing regions of Nigeria has become an escalating environmental challenge, particularly within informal settlements where planning regulations are weak and infrastructure is inadequate. This study examines the environmental, structural, and socioeconomic determinants of flood vulnerability in the informal settlements of Aba Urban, Abia State. Using a mixed-methods approach, data were collected through household surveys, key informant interviews, field observations, and secondary hydro-meteorological records from the Agrometeorological Department of NRCRI Umudike (1999–2023). Descriptive and inferential statistical techniques including paired sample tests, Pearson’s correlation, and Spearman’s rank correlation were applied to assess patterns of exposure and identify critical risk factors. Results indicate that low terrain gradients, sandy-loam soils with inconsistent infiltration capacity, and high-intensity rainfall significantly heighten environmental exposure. Structural deficiencies, such as narrow and obstructed drainage channels, absence of engineered stormwater systems, and widespread building encroachment on natural waterways, further exacerbate flood impacts. Socioeconomic characteristics including low income, limited education, high population density, and long-term residence contribute to heightened susceptibility and reduced adaptive capacity. The findings confirm that flood vulnerability in Aba’s informal settlements is multidimensional, arising from the interaction of environmental hazards, infrastructural weaknesses, and social inequalities. The study recommends integrated interventions involving drainage reconstruction, strict enforcement of urban planning policies, community-based monitoring systems, targeted environmental education, and comprehensive hydrological mapping. These measures are essential for enhancing resilience and reducing flood-related risks in the affected communities.