GIS-based mapping of flood vulnerability and risk in the Bénin Niger River valley

Introduction

In recent decades, flood disaster has been occurring frequently in West Africa. Located in the heart of West Africa, the Niger River Basin has not been spared the flood hazard that is threatening human security in the region. Those living in flood affected areas face the risk of severe damage to their infrastructure, the loss of their livelihood as well as a substantial threat of injury and death.

These hazards can hamper efforts to escape poverty and set back development gains. Despite the threat, there is very scant research documenting flood risk. Without flood risk analysis, opportunities to reduce vulnerability could be missed and the impact of development work may be undermined.

Methods and Tools

With these concerns in mind, this study* addresses flood vulnerability and risk in the Bénin Niger River Valley including the two municipalities Karimama and Malanville. A GIS-based mapping and theory-driven indicator approach was applied.

*download the full text from the right-hand column.

Lessons Learnt

The assessment revealed that almost 90 % of the district is located in a flood hazard footprint and is consequently exposed to a high flood risk. However the municipalities are not exposed to the same degree of flood risk due to their different degrees of vulnerability. The vulnerability indicators chosen in the framework of this study show that the municipality of Karimama is more vulnerable than the municipality of Malanville. This discrepancy is due to higher poverty rates and weaker pre-existing physical, social, economic and environmental vulnerability conditions present in Karimama.

Outcomes and Impacts

The risk assessment revealed that 70% of the districts in the area are at high flood risk. In view of potential extreme climate events, we assert that there is an urgent need to have high resolution data in order to deepen research about the flood risk in the Niger River basin.