Distributed computation of 2D inundation modelling

The river basins in Taiwan are small with steep bed slopes, which result in short time of concentration and high flood discharges during the typhoon or heavy rainfall. Consequently, the inundation in local area happens quickly and causes the very short time for taking emergency responses. Numerical models are widely adopted for predicting the flood risks. The study integrates the HEC-HMS hydrological model, the 2D inundation model, and the real time rainfall monitor information from the Central Weather Bureau for building a real time distributed inundation computation system. The system is applied to whole Taiwan which includes 54 simulation areas and the results can be finished between 3 hours lead time before inundation occurs. The results help the emergency decision agencies forecasting the inundation during typhoon, warning the residents, and taking proper actions to mitigate hazard damages.