| Summary: | 碩士 === 國立臺灣大學 === 生物環境系統工程學研究所 === 106 === In recent years, urban flooding caused by heavy intensity rainfalls has occurred more frequently, since the frequency of extreme rainfall events is increasing. The loss of life and properties could be effectively reduced by urban flooding simulation, which provides reference for flood and disaster prevention. Nowadays, the urban flood inundation models have gradually matured. Most of them couple the one-dimensional (1D) sewer flow model (SFM) and the two-dimensional (2D) overland flow model (OFM) to simulate dynamic flow interactions between storm sewers and overland surface. They can reasonably simulate the flooding of urban areas. However, urban flood inundation model nowadays is often used for pre-simulating instead of real-time forecasting due to long simulation time for two-dimensional overland model.
In this study, we first utilize the concept of cellular automata to propose a two-dimensional rapid overland flow model with a simple water transition rule instead of solving the momentum equation. The proposed two-dimensional rapid overland flow model is then coupled with the one-dimensional (1D) sewer flow model to simulate the dynamic flow interactions between storm sewers and overland surface, and thus constructing our rapid urban flood inundation model. As for urban flood inundation model that solves the shallow water equations is herein called the traditional urban flood inundation model.
In this study, the Muzha sub-catchment area of Wenshan District, Taipei City is selected as the research area. Two short duration heavy intensity rainfall events are used to compare the proposed rapid urban flood inundation model and the traditional urban flood inundation model. The comparison results show that the proposed model can provide considerably good simulated results to those of the traditional model. Besides, the simulation time of the proposed model is only 15% of the traditional model. It is evident that the proposed model can be a useful alternative of the traditional model.
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