River Flood Risk Forecasting Using Hydrological and Hydraulic Models

Nyabugogo River within Nyabugogo catchment in Rwanda is being flooded every year resulting in human losses and economic losses. For sustainable flood management; flood risk assessment is a useful component as it demonstrates the expected water depth floodplain area and the expected damage for each event. The aim of this study was to forecast Nyabugogo river flood risk and propose mitigation measures which can reduce flood impacts by using HEC-HMS integrated with HEC-GEOHMS and HEC-RAS integrated with HEC-GEORAS. The study focused on assessing the causes and impacts of the flood; assessing the existing flood management measures and describing the geospatial characteristics of the catchment then generating inundation maps and water depth for each event modeled. This research can provide a basic support for decision making and also can help in the planning and management of land use and future probable flood event within the catchment.