Author(s): Tsung-Yi Pan; Shiang-Kuan Chang; Jihn-Sung Lai; Yih-Chi Tan
Linked Author(s):
Keywords: Climate change; Downscaling; Levee failure; Inundation simulation
Abstract: Due to the high density of political, economic and cultural activities in urban areas, building levee is the common measure to protect cities, where river run through, from floods. However, the extreme rainfall event induced by climate change would cause more serious inundation if levees are broken. This study applied downscaling technique, a flood forecasting model and an inundation model to investigate the impacts of climate change and levee failure on urban areas. The rainfall output of the global circulation model, named HadCM3, was selected to be downscaled and to modify regional rainfall due to climate change in Taipei. The inundation simulation couples the real time flash flood forecasting model for the Danshuei River with a two-dimensional inundation model. After the discharge of overflow is determined due to levee failure, the real-time inundation module can calculate the possible flood area and the depth of inundation quickly and accurately. Based on the inundation model linked to flood forecasting model, the inundation disaster happened in Taipei due to levee failure during Typhoon Aere in 2004 was simulated as an example. Then, the scenarios of inundation induced by levee failure and the floods generated by 200-yr return-period design rainfalls with different scenarios of climate change were performed to compare with the inundation event in 2004. The simulated results show the impacts of climate change on inundation area if the levee is broken again, which can provide important information for decision making of adaptation to climate change.
Year: 2010