Environmental Impact of Flooding on Kosofe Local Government Area of Lagos State, Nigeria: A GIS Perspective

Abstract

The study identified and assessed the environmental impact of flooding on Kosofe Local Government Area of Lagos state, Nigeria. This was with a view to suggesting an integrated strategy and management plan for sustainable environment in the study area. The study therefore integrated IKONOS and Land-SAT Images of 2010 with spatial resolution of 5m and 30m respectively. Aerial photography of 2010 was also acquired with ground truthting to carry out the exercise. Structured questionnaire was administered to elucidate data on socio economic characteristics of the residents; building use; distance of building from floodplain; source of land acquisition and impact of flooding on the environment among others. Digital image processing was carried out for satellite imageries. Land uses were identified and classified from the satellite imageries. Digital Elevation Model (DEM) was generated using ILWIS 3.4 software to depict the topography of the study area. Chi-Squared statistical test was adopted for the study. Results obtained show that there is strong correlation between incidence of flooding (FLOOD) and poor refuse disposal practices (REFUSE), inadequate setback from rivers (SETBACK) and lack of building plan approval from relevant authority (APPROVE). The study recommended enlightenment programmes for the residents of the study area to increase their level awareness about the causes, consequences and control of flooding.

Keywords: Flood, GIS, Kosofe LGA