Mapping Flood High Priority Areas in Southern Nigeria

Abstract

ABSTRACT
Floods are among the most frequent and costly natural disasters in terms of human and economic loss. Flood disasters can be attributed to the unnecessary risks people take when they encroach on floodplains. The methodology adopted for this research includes Remote Sensing and GIS techniques along with spatial and non-spatial data such as, rainfall, soil and DEM data was used to delineate flood susceptible areas for the different river basin in Southern Nigeria. The result of the spatial analysis on flooding in the 13 states of Southern Nigeria indicate that the Anambra/Niger Delta/Imo River basin accounts for 74% and while the rest of the basins such as Ogun/Osun/Osse river basin, Benue river basin and Cross river basin accounts for 26% which is more than three fourth of the area that fall under high flood hazard. The z-scores were used to measure the statistical significance of flood vulnerability. This was used to identify concentrations were vulnerability to flooding and flood hazard are high, where floodplain is located and where/when flood peak intensities occur. Towns in Southern Nigeria affected by flooding and the level of risk were mapped. Based on the information provided from the flood hazard and vulnerability study using GIS spatial queries Flood High Priority areas (also known High Flood Risk areas) were selected along with the flood estimated runoff time for Southern Nigeria. High Priority areas are areas that require urgent attention from flood hazard and risk. However, this will serve as an early warning system. Also flood hazards zoning, assessment and risk analyses will provide the major prerequisite components for flood disaster management before any assessment of the impact of a flood event can begin.

Keywords: Flood, Hazard, Vulnerability, Southern Nigeria, High Priority areas, GIS and Remote Sensing.

Cite this Article: Ibeabuchi Uwadiegwu and Nwilo Peter Chigozie. Mapping Flood High Priority Areas in Southern Nigeria. International Journal of Satellite Communication & Remote Sensing. 2020; 6(1): 35–38p.