Mapping and Analysis of Flood Risk Zones in Uyo Urban Nigeria Using Satellite Imagery

Abstract

Sequel to the uncountable and catastrophic effects of flood in different places all over the world, several mitigation measures have been developed by different people in different places to manage it. Unfortunately, as seen in literature, most of the mitigation measures lack proper mapping of the physical environment. It is to this effect that this study used GIS and remote sensing to identify flood risk areas within Uyo Urban so as to produce an easily understood GIS based flood risks map of the area. The ASTER DEM and Landsat ETM+ images of 2015 of the area were used in this research to characterize the topography and assess the impact of flooding. Three flood risk maps were produced identifying three category risk zones, high, medium and low risk zones. Factors that affect flooding in the study area were outlined and they include population explosion, urbanization and climate change. The area within each of the risk zones was calculated. The total area covered by the high risk zone was 8,878,080Sq km (52.50%) while the area of the medium and low risk zones were 7,873,810Sq km (47.15%) and 5,782,00Sq km (0.34%) respectively being the land use within Uyo Urban. Finally, strategies for mitigating against flood risks were discussed which include development of flood early warning system, structural and non-structural measures. And some recommendations were made to help researchers to improve on flood management in the country which include, there should monitor or discourage built-up areas that are located within the flood plains in Uyo Urban and Provision of adequate drainage and channelization system.

Keywords: Flood, Flooding, Natural hazard, Management, Runoff, Mitigation