PARTICIPATORY APPROACH FOR FLOOD VULNERABILITY ASSESSMENT IN SELECTED COMMUNITIES DOWNSTREAM OF JEBBA DAM NIGER STATE, NIGERIA

Abstract

People possess a creative set of strategies based on their local knowledge that allow them to stay in flood-prone areas. Stakeholders involved with local level flood risk management (FRM) often overlook and underutilize this local knowledge. There is thus an increasing need for its identification, documentation and assessment. Based on qualitative research, this research paper critically explores the notion of local knowledge in Jebba Dam.The aim of this study is to map the vulnerability of certain communities downstream of Jebba dam for flood hazard by using participatory geographical information system approach (PGIS). The primary data for the study were collected using Global Positioning System (GPS), focus group discussion (FGD) and high-resolution satellite image downloaded from Google Earth. Participatory sketch mapping method combined with Field surveying and GPS points taken with geo-referenced satellite image through step-by-step approach to record information on spatial extent of flood in the community to obtain valid exposure to flood map was adopted, GIS and remote sensing techniques is used to classified the terrain of the study area to produce flood vulnerability map based on elevation and to map the community infrastructure to generate flood vulnerability map based on distance. The produced sketch map from participatory community mapping showed local knowledge on flooded and non-flooded areas, flood channel, direction and flood entrance points that support the exposure to flood where identified. Exposure to flood Map results showed that in kosogi community the flooded area is 16.2hectre and not flooded is 17.84hectre, 48% of the area is flooded. In Lwafu community the flooded area is 25.5hectre, not flooded building area is 9.72hectre, 66.25% of the area is flooded. In Sunti community the flooded area is 9.72hectre and not flooded area is 4.05hectre, 62.505% area is flooded. Results show that participatory approach (PGIS and PMAPPING) can be useful to record local spatial knowledge on flood vulnerability that supports the development of vulnerability reduction measures. By helping community members understand and manage vulnerability, this approach has the potential to become an important mechanism to support vulnerability reduction in Jebba dam downstream.