都會區快速淹水模擬模式之研發與應用

Development and Application of Rapid Flood Inundation Simulation Model in Urban Areas

林吉堃(Chi-Kun Lin)

指導教授 ： 張倉榮

國立臺灣大學/生物資源暨農學院/生物環境系統工程學研究所/碩士(2018年)

https://doi.org/10.6342/NTU201803615

摘要

近年來發生極端降雨事件的頻率增加，使得都會區淹水災害事件頻傳，藉由淹水模擬結果提供防洪防災工作之參考，可有效降低災害帶來的生命財產損失。現今都會區淹水模式發展已逐漸成熟，其多以求解淺水波方程式之二維傳統漫地流模式耦合一維雨水下水道模式並以雙向交互演算進行兩者之銜接，其可合理模擬都會區之淹水情況。然而，現今都會區淹水模式因其二維傳統漫地流模式的計算時間較長而導致其仍無法大量運用於即時預報，目前多運用於事前模擬。
本研究以細胞自動機(Cellular automata)之理論發展二維快速漫地流模式，利用簡易之水體傳輸規則來近似動量方程式，並將其與一維雨水下水道模式耦合，此兩模式間為雙向交互演算，以此建構都會區快速淹水模式。至於目前以淺水波方程式求解地表水體運動的都會區淹水模式，則統稱為都會區傳統淹水模式。
本研究以臺北市文山區木柵次分區為研究區域，透過兩場短延時強降雨事件進行都會區快速淹水模式與都會區傳統淹水模式之比較。結果顯示，都會區快速淹水模式能得到與都會區傳統淹水模式非常相近的結果，且運算速度上其模擬時間只需要都會區傳統淹水模式的15%，顯示本研究所發展之都會區快速淹水模式能取代都會區傳統淹水模式。

關鍵字

細胞自動機 ； 二維快速漫地流模式 ； 交互演算 ； 都會區快速淹水模式

並列摘要

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.

並列關鍵字

Cellular automata ； 2D Rapid overland flow model ； Dynamic flow interaction ； Rapid Urban Flood Inundation Model

參考文獻

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