Flood Vulnerability Assessment in Ilaje, Ondo State, Nigeria

Abstract

Flood as a natural disaster has been described as a phenomenon which is a part of earth’s bio-physical processes, which can be devastating due to anthropogenic activities and climatological factors. The study assessed the land use land cover changes (LULCC), assessed the surface temperature changes and evaluated the flood vulnerability level in the study area between 1986 and 2015 using geospatial techniques. Supervised classification, using maximum likelihood algorithm, was employed for LULC, mono-window algorithm method was adopted in the study to retrieve the Land Surface Temperature (LST) from the imageries selected for this study and sea level rise and storm surge scenario was modelled at different flood heights. The result showed changes in LULC characteristics, mean ± standard deviations of 22.0°C ± 0.71; 31.12°C ± 0.81; and 24.6°C ± 0.86 were recorded in 1986, 1999 and 2015 respectively in the study area. Higher LST values were however observed in most built-up and bare surfaces than other land use land cover classes while at projected 2, 4 and 6 meters rise, it is expected that 6.56% of the total surface area of the study area will be highly vulnerable to flooding. It is therefore established that the area is exposed to flooding due to uncontrolled human activities causing climate change which is evident in the land surface temperature values derived and the Land use Land Cover Changes in the study.