Assessment of Flood- Prone Areas in Anambra-Imo River Basin of South-East Nigeria
Floods have become a common natural disaster which has claimed many lives, displaced millions and resulted to the destruction of properties and degradation of contiguous farmlands. This research paper explored the potentials of Geographic Information System (GIS) integrated with Multi-criteria Decision Analysis to evaluate the causative factors for flooding and identifying flood-prone areas for the purpose of planning for disaster mitigation and preparedness, using Anambra-Imo river basin of the south-east, Nigeria as a case study. The data used in this study were obtained from Federal Ministry of Environment, Forestry Management Evaluation and Coordination Unit (FORMECU) and Shuttle Radar Topography Mission (STRM) Website were entered and use to develop a flood risk information system. Some of the causative factors for flooding in watershed such as annual rainfall, slope, drainage pattern, soil type and land use/land cover. Multi-criteria analysis was used to rank and display flood risk zones, while the analytical hierarchy method was used to compute the selected criterion and the percentage of contribution derived from the factors were rainfall (33.9%), drainage (25.5%), slope (19.7%), soil type (15.2%) and land use/land cover (0.6%). At the end, maps showing areas that are prone to flooding were generated with a view of improving stakeholder capacities for understanding, analysis and management on the menace posed by the disaster.
© Department of Geography, Obafemi Awolowo University Ile-Ife, Nigeria 2016