Mapping Informal Settlements and Housing Quality in Port Harcourt Using Satellite Imagery

Port Harcourt, the capital of Rivers State and the commercial hub of Nigeria's South South geopolitical zone, contains extensive informal settlement areas characterised by high population density, inadequate infrastructure, and poor housing quality. This study applies remote sensing techniques to map the spatial extent and internal heterogeneity of informal settlements in Port Harcourt, with particular attention to housing quality indicators visible at the sub-metre satellite image resolution. Pleiades-1 very high resolution imagery acquired in 2023 was classified using machine learning-based image segmentation in eCognition software, with six housing quality classes defined by roof material, plot regularity, road accessibility, and vegetative cover. Field validation surveys were conducted in Diobu, Rumuola, and Borokiri communities, where structured household questionnaires on tenure security, access to water and sanitation, and maintenance investment were administered to 280 respondents. Classification accuracy assessments returned an overall Kappa coefficient of 0.81, confirming reliable discrimination among quality classes. Results identify Diobu as the zone of highest informal settlement density, with approximately 68 percent of structures classified as substandard based on the adopted criteria. The study finds strong spatial associations between informal housing prevalence and proximity to industrial buffer zones, which discourage formal land development. Findings provide a baseline for Port Harcourt's slum upgrading programme and inform targeted infrastructure investment under the Rivers State Urban Renewal Authority. Keywords: informal settlements, housing quality, remote sensing, Port Harcourt, South South Nigeria.