Modelling and Assessment of Flood Vulnerability of Settlements in Owerri West L.G.A in Imo State, Nigeria Using Remote Sensing and GIS

Abstract

Mitigation of impact of flooding is successful only when detailed knowledge of vulnerability of people and facilities to flooding is available. Therefore, in this study, attempt has been made to demarcate the study area into different levels of flood vulnerability potential zones using remote sensing and Geographic information system (GIS). It identified spatial variations in flood vulnerability potential levels with a view of fostering the best approach for flood management. Software used include ArcGIS10.3, ERDAS Imagine and supher11. Data used include ASTER DEM of 30m resolution, LANDSAT imagery of resolution 30m, administrative map of the study area, GPS point locations of communities within the study area and population statistics of the study area. These datasets were populated in GIS window and flood causative factors such as slopes, elevation, land use, proximity to the river, population density, and flow accumulation were extracted and integrated to demarcate the study area into levels of vulnerability potentials and determine communities and population in different vulnerability categories. The study revealed that 15.729 (5.22%) square kilometers, 232.575 (76.97%) square kilometers, 53.747 (17.79%), square kilometers, and 0.093 (0.03%) square kilometers of the study area are under high vulnerability, moderate vulnerability, low vulnerability. and very low vulnerability potentials respectively. It further revealed that approximately, 7361, 108843, 25153 and 44 number of persons within the study area are respectively residing within these vulnerability zones.