Scenario Simulations and VR for Flood Disaster Emergency Responses in Dansuie River

The area of the Dansuie River watershed located in the northern Taiwan is 2,726 km. The main stream runs 159km through the Taipei metropolitan areas as the political, economic, and cultural centers of Taiwan. Owing to short and steep runoff path-lines and non-uniform rainfall patterns, large floods arrive rapidly in the middle-to-downstream reaches of the watershed, causing serious damage. In order to mitigate the flood hazard, the 10th River Management Office of Water Resources Agency of Ministry of Economic Affairs, Taiwan, has developed the Real Time Flash Flood Forecasting Model for Dansuie River (RFFF) that can perform the tidal forecasting, rainfall forecasting, rainfall-runoff simulation, and unsteady river flow simulation. In RFFF model, this study implements a real-time 2D inundation module that links the RFFF model to simulate the inundation real time and display the results by 3D virtual reality (VR) technique. The real-time flood forecasting simulation by RFFF model copied with 2D inundation module is performed based on the selected prone inundation lowlands. After the way of overflow is determined, the real-time 2D inundation module can calculate the possible flooding area and the depth of inundation efficiently. The module can produce 3D landform as the background of inundation display after the module reads DEM. Based on the results of the real-time inundation module, the scenario of inundation is shown via a dynamic flooding virtual reality, and provides decision making information. Keyword: Real Time, Flood Forecasting, inundation, DEM, virtual reality.