Determining vulnerability to impacts of floods amongst heterogeneous communities in the Nyamwamba catchment, Western Uganda.

Abstract

On the 1st of May, 2013 the Nyamwamba catchment in Western Uganda experienced flash flood episodes that have re-occurred over the years, destroying property, killing and displacing residents without a corresponding reduction in the communities’ vulnerability to flood impacts. The study aims to assess vulnerability to impacts of floods amongst communities in the Nyamwamba catchment utilising a community based participatory approach and two model-based GIS approaches. These approaches are used because most studies tend to focus on model-based approaches and do not incorporate input from the community. The participatory approach involved community participation to identify, prioritise and map their vulnerability to flood impacts. The first model-based GIS approach involved linking physical and socio-economic unsafe conditions that indicate vulnerability to the flood hazard, and used only secondary data whereas the second model based GIS approach was the Composite Flood Vulnerability Index (CFVI) method, which involved developing an indicator framework and index to rank vulnerable communities and used both primary data and model-based GIS techniques. The participatory approach revealed 8 parishes as being in high-risk vulnerability zones and identified and ranked 8 major factors that made the community vulnerable to flood impacts. The first model-based GIS approach revealed that an area of 63sqkm was covered by the flood hazard and 4 parishes were identified as having the most vulnerable communities. The second model-based GIS approach revealed Nyamwamba as the most vulnerable division with a CFVI of 0.58595. Given how diverse vulnerability is, district authorities should deliberately include flood vulnerability management programmes in their development plans focusing not only on physical but also socio-economic dimensions of vulnerability such as reducing poverty and improving health services.