Assessing physical vulnerability to impacts of flood hazard along River Nyamwamba. case study: Kasese district

Abstract

Climate change has made assessing flood susceptibility more crucial. This is so that vulnerable individuals in specific groups may be more easily identified, and so that the causes of their vulnerability can be better understood. Kasese region experiences seasonal flash floods with devastating consequences on the people, the natural and built environments. In contrast with developed countries, researchers and flood managers largely ignore Participatory Geographic Information System which is used by flood managers as a reactive, top-down post-flood strategy of relief and rescue that integrates the perspectives and experiences of the people affected by flood occurrences with technological and traditional procedures. In order to analyze the community's susceptibility to the historical flood risk, this study used PGIS to carry out a vulnerability assessment in Kasese near the Nyamwamba River. The datasets used were those for rainfall data from MWE, satellite imagery from Google Earth and SAS Planet, DEM from NASA, field data (such as GPS location, interviews, and observations), administrative data, and land use data. The Empirical methods of measuring physical vulnerability was used to derive off damage data from previous hazard incidents to gather information about the extent of physical harm to the built environment. Results showed that the study investigated the spatial distribution of the built-up area at risk to flood hazard, establishing a baseline to evaluate physical vulnerability, and that it was discovered that buildings that were highly susceptible to flood hazard were those that were close to the river as well as, the type of construction material used, and this gave a basis on why certain buildings are susceptible more than others. Most of the structures in the Kasese region are made of mud, wood, brick, and concrete. Structures made of pliable materials like concrete fare better in floods than those made of natural materials like wood and mud. However, this does not mean that the concrete structures are any less vulnerable considering that some of the concrete structures that were really close to the river were completely destroyed. Kanyaruhogo (89.62%) and Namuhuganorth east villages (62.68%) had the most severely damaged infrastructure, while Mburakasaka (0.65%) and Kanyajuki villages (6.74%) had the least impact of damage, according to the physical vulnerability map of the study area, which was classified as high, medium, and low vulnerability in terms of damage to buildings.