A hydrometeorological flood forecasting system for the reservoir control in the Red River

This paper describes a hydrological flood forecasting system for the Red River basin, across China and Vietnam, measuring 144,000 km² in size at the Son Tay streamgauge. The research objectives were to setup a hydrometeorological chain to forecast discharge flowing into reservoirs and at some streamgauges for flood control in downstream areas, including the heavily populated Northern Delta. The distributed hydrological model DIMOSHong forced by Quantitative Precipitation Forecasts provided by the BOLAM meteorological model and GIS information, including the orography, soil type, land use, river network of the basin was adopted. The forecasting chain structure and setup is described. Verification of the QPF versus observed rainfall at different scales showed a very good timing of the precipitation and flood forecast but some overestimation of the precipitation forecast. Resulting flood forecast up to 5 days in advance were reasonably good in view of reservoir operation.