Taiwan Flash Flood Forecasting

Hot weather in the summer makes people tend to do water activities in the mountains. Torrential rain that triggers flash flood may occur and disappear in an hour. In average, Taiwan wild rivers kill 200 a year. Due to lack of gauging stations in the mountains, no warning system was developed for flash flood for the wild rivers. To reduce the risk of water activities in the mountains, the branch office (Frogtech) of Nelen en Schuurmans and NCU developed a flash flood forecasting system that gives a forecast of 3 hours of lead time every 10 mins. Each update requires 3-4 mins.

NCU provides the rainfall nowcasts of 3 hours of lead time every 10 mins to ensure the torrential rain can be captured. Frogtech uses the Lizard platform and 3Di hydrodynamic model to develop the flash flood forecasting system to ensure that every location in the catchment can be calculated. Every flood forecast can be carried out in 4 mins. The system is highly evaluated as: (1) software as sensors with the advantage of any location and sensor quantity under a limited cost, (2) system can be deployed very easily as long as detailed DEM is available; (3) forecasts of 3-hour lead time enabling earlier evacuation.