建蔽率對都市淹水影響之模擬

Effect of building coverage ratio on urban Inundation Simulations

邱建勛(Chien-Hsun Chiu)

指導教授 ： 許銘熙

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(2011年)

https://doi.org/10.6342/NTU.2011.02984

摘要

近年來台灣都會地區迅速發展，人口逐漸往都市集中，尤其是大台北地區為台灣都市化程度最高處，人口相當密集，為滿足居民生活需求，都市內興建了大量且密集的建物，而增加之建物會改變原本地表水流狀況，產生束縮水流及增加額外形狀阻力的現象。
本研究主要目的在研發一套能以一般淹水計算網格反應建物效應之淹水計算。模式中依照實際建蔽率當做模式輸入項目，模擬含建物時淹水情形，並調整通水表面阻抗及增加建物形狀阻抗，之後進一步計算當淹水深度達一定高度時，水流由建物外部流入內部體積轉換的情形，以反應建物於淹水時的實際現象。
本文將模式應用於淡水河與基隆河環繞之台北市中央區，進行實際案例模擬，以2001年納莉颱風雨量資料，分別比較於淹水模式中加入建物前後淹水範圍及淹水深度的變化，結果顯示未加入建物之淹水模擬，會低估都會地區的淹水情形，因此當我們以二維漫地流模式進行都會地區地表淹水模擬時，於淹水模式中加入建物因子並依照建物大小調整水流流況，可使淹水情形較符合實際狀況。

關鍵字

淹水模式 ； 建蔽率

並列摘要

In recent years, the population is concentrated in urban areas because of the rapid development of metropolitan cities in Taiwan. Especially in Taipei City, there was the highest level of urbanization and dense population. In order to meet the requirement of residents, a large number of buildings were constructed. The original situation of surface water flows were changed by the additional buildings. As a result, the overland flow is confined by the reduction of the flow width and resisted by the form drag caused by the buildings.
The main purpose in this study is to develop an inundation model in a general computing grid which responses the storage and resistance effects of buildings for flooding. Building coverage ratio is a significant parameter in the simulation model. The Manning roughness coefficient is adjusted with confined flow resistance and building form drag. The flooding water flows into buildings when the inundation depth excesses a certain height which reflects the actual phenomena in the flooding with the buildings.
The model was applied on the central Taipei City which Tamsui River and Keelung River surround. It were compared the inundation depth and extent with and without the buildings existed. The rainfall data of Typhoon Nari event in 2001 was used for simulation. The results showed that in case of without considering the buildings, the inundation was underestimated in the metropolitan areas. Therefore, with consideration of the building coverage, the presented inundation model which adjusts the water flow conditions in accordance with the size of building in urban areas will make the inundation coincident with the actual situation of flooding.

並列關鍵字

Inundation model ； building coverage ratio ； SWMM

參考文獻

19. 陳彥宏，2008，”流域格網局部細化之淹水模擬”，國立台灣大學生物環境系統工程研究所碩士論文。

16. 陳志鴻，2004，”應用淹水模式評估都市區雨水下水道之效能”，國立台灣大學生物環境系統工程研究所碩士論文。

18. 江明晃，2006，” 台中市區數值地形解析度對淹水模擬結果之比較”，國立台灣大學生物環境系統工程研究所碩士論文。

20. 鄒亞達，2009，”淹水細化網格邊界處理之研究”，國立台灣大學生物環境系統工程研究所碩士論文。

39. Lager, J. A. and Smith, W. G., "Urban Stormwater Management and Technology–An Assessment", U.S. EPA Report, EPA-67012-74-040, 1974.