INITIATIVE EVALUATION OF COUPLING A HIGH-RESOLUTION WEATHER MODEL WITH A HYDROLOGICAL MODEL FOR HYDROLOGICAL FORECASTING

Abstract

In this study, the distributed hydrological model is coupled with the meteorological numerical model to calculate short-term hydrological forecasts for the Luy sub-basin in Binh Thuan province. The meteorological model uses data from a global forecast model with three grids with a resolution of 9 km, 3 km, and 1 km, respectively and the hydrological model's grid has a resolution of 250 m. The Independent hydrological model was calibrated and validated with grid rain combined with rainfall data measured on the ground, achieving high results with Nash index from 0.9. However, when coupling, the quality of forecasted flow decreased significantly with the Nash index of 0.5. However, the results show that the model responds well to changes in inputs, the flow is sensitive to the predicted rain. To ensure accuracy and increase forecasting time, it is necessary to study and adjust meteorological forecasting results before transferring them to the hydrological model. Experiments in the research show that coupled hydro-meteorological use is a new, feasible direction in hydrological forecasting.