Spatial Analysis of Vulnerability to Flooding in Port Harcourt Metropolis, Nigeria

Abstract

This study analyzed the vulnerability to flooding in Port Harcourt metropolis, Nigeria, by creating vulnerability indices and comparing these indices across the 13 zones that make up Port Harcourt metropolis. The integrated vulnerability assessment approach using indicators was adopted. The indicators were grouped into adaptive capacity, sensitivity, and exposure based on the Intergovernmental Panel on Climate Change definition of vulnerability. The data on these indicators were obtained from fieldwork, questionnaire, and map measurements. Principal component analysis was performed to obtain the first component scores which were used to weight the variables before calculating the vulnerability indices of the 13 zones. The vulnerability indices results show that Mgbuosimiri (Zone K) is relatively the most vulnerable, whereas the least vulnerable is Eligbolo (Zone D). Cluster analysis was used to group the different vulnerability indices to produce a vulnerability map showing the spatial pattern of the different flood vulnerability levels (i.e., very high, high, low, and very low vulnerability levels). The spatial pattern of the vulnerability levels increases toward the north west, south west, south, and north east, and decreases toward the central of Port Harcourt. However, the vulnerability map can be used for the reduction of damage potential by integrating its outputs into spatial planning and emergency planning.