THE ONLINE SUPPORTING SYSTEM FLOOD WARNING FOR VU GIA WATERSHED, QUANG NAM PROVINCE, VIETNAM: CONCEPTUAL FRAMEWORK AND PROPOSED RESEARCH TECHNIQUES

摘要

Vu Gia watershed is located in the Central Vietnam where hurricanes represent a constant natural threat to human lives and physical infrastructure. Hydrological monitoring is considered as an effective tool to respond to high flood events by preventing and mitigating damages. The purpose of this study was to conduct and perform hydrological modelling to determine areas prone to be flooded during high rainfall events in the upstream Vu Gia watershed. The methodology involved: hydro-climatic data base building, a detailed Digital Elevation Model (DEM), a land use map, and a soil map of the basin. With all the data, SWA T model (Soil and Water Assessment Tool) was used to predict discharge values. These discharge values were used, along with the DEM, to predict flood hazard areas in the downstream of Vu Gia watershed floodplains. This procedure was made using the HEC-RAS model (Hydrological Engineering Center-River Analysis System). Finals results show the exact location of areas with high, moderate and low risk to be flooded at specific high flood events. The results also provided the location of critical areas, so that an early warning system can be located. Additionally, as apart of this study, valuable information was provided to at-risk residents about how to prevent and mitigate the effect of flood-related damages in low land areas of Vu Gia watershed.