[01] Jean Damascene Rutagengwa, Faculty of Environmental Studies, University of Lay Adventists of Kigali, Kigali, Rwanda. [02] Lamek Nahayo, Faculty of Environmental Studies, University of Lay Adventists of Kigali, Kigali, Rwanda. [03] Mugisha Philbert, Faculty of Environmental Studies, University of Lay Adventists of Kigali, Kigali, Rwanda. [04] Elizabeth Yambabariye, Faculty of Environmental Studies, University of Lay Adventists of Kigali, Kigali, Rwanda. [05] Justin Nsanzabaganwa, Faculty of Environmental Studies, University of Lay Adventists of Kigali, Kigali, Rwanda.

Mapping of flood hazard reveals its occurrence likelihood and increases the preparedness and adaptation among the community. This study aimed to spatially analyze flood hazard towards its risk reduction in Kamonyi district, southern Rwanda. The study used secondary data on flood events (deaths and injuries, destroyed houses and damaged croplands, road and electrical lines damaged and lost livestock) collected from the Rwanda’s Ministry in Charge of Emergency Management (MINEMA) from January 2013 to April 2020. These recent flood events, literature review and experts opinions helped to select ten flood triggering factors namely elevation, slope, rainfall, land use and land cover (LULC), Normalized Difference Vegetation Index (NDVI), Topographic Wetness Index (TWI), distance from roads, distance from rivers, lithology and soil texture. These factors were merged together to produce flood hazard map through the Fuzzy Overlay method of the Spatial Analyst Tools in the Geographic Information System (GIS). The analysis highlighted elevation, slope and rainfall as major factors and flood mapping marked the Rukoma, Gacurabwenge, Musambira, Nyarubaka and Kayumbu sectors as highly prone to flood. For the prediction of flood occurrence from 2020 to 2050, the authors used Microsoft Excel and referred to recent flood cases. The results showed that Karama and Rugarika sectors are likely exposed to future occurrence. For the flood risk reduction, policy makers are suggested to consider each sector since the experience on flood differs by sector and rainwater harvesting along with development of terraces would help to minimize the runoff from which results flooding. This flood hazard mapping can help decision-makers, economic operators and other occupants to determine the areas that may potentially be impacted while the prediction of flood future occurrence will help the decision makers in better planning as well.

Flood, Geographic Information System, Hazard, Kamonyi District, Risk Reduction, Rwanda

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