https://scholars.lib.ntu.edu.tw/handle/123456789/85820
標題: | 行政院國家科學委員會補助專題研究計畫成果報告:防洪示範區淹水境況模擬與決策支援系統之研究─子計畫:基隆河流域整治段颱洪災害淹水境況模擬(I) | 作者: | 張倉榮 | 關鍵字: | 淹水境況模擬;溢淹洪水;洪水平原;淹水區域;Inundation Scenario Simulation;Overbank Flooding;Floodplain;Inundation Zone | 公開日期: | 2001 | 出版社: | 臺北市:國立臺灣大學生物環境系統工程學系暨研究所 | 摘要: | 台北都會區為一盆地地形,區內人口密集,淡水河及其主要支流新店溪、大漢溪、基隆河匯流於盆地內。由於盆地內地勢本屬低窪,造成每年颱洪時期,洪水氾濫成災。為求能減除洪災,政府自民國71 年起分三期在大台北地區實施「台北地區防洪計畫J ,以人口較為密集之淡水河主幹流、大漢溪、新店溪及基隆河在台北縣市界之南湖大橋以下地區為實施範圍,修築可抵禦200 年重現期洪水之高標準堤防。然而,基隆河在南湖大橋以上之地區,包括台北縣汐止市、瑞芳鎮及基隆市七堵、暖暖區,過去由於人口較為稀少,並無堤防之保護,在歷經二、三十年之都市化演變與急遽發展,市鎮發展與水爭地,該地區基隆河主河道兩側高樓林立,兩岸過度開騷造成河道斷面減少”因此,在洪水期間高漲的基隆河水位沿峽谷地形漫淹到該地區,引發更嚴重之淹水災害。如民國87 年10 月15 日端伯颱風侵襲台灣,連續24 小時最大降雨量未滿20 年重限期降雨,但卻造成汐止五堵地區嚴重的水息,淹沒了汐止市最繁榮、人。最密集的23 個里;十日後,芭比絲颱風外圍環流過境台灣,在25 日及26 日兩天之內,再次造成汐止五堵地區接連兩次淹水,另一方面,靠近基隆河岸,但已獲200 年重現期高標準堤防保護之台北市南港、內湖、松山區,此次並無重大淹水災情。由此可見,汐止五堵地區之淹水與基隆河外水溢岸氾濫.急息相關,故值得進一步分析與研究河川主流與洪水平原漫地流問隨水位高低而互動之關係。 本計畫為「防洪示範區淹水境況模擬與決策支援系統之研究(一)」整合型計畫之子計畫七,其計畫之主要目的在於探討基隆河治理工程方案中之整治範圍在不同降雨條件下之淹水境況,以做為防洪決策支援之依據。研究範圍為經濟部基隆河治理推動小組所提出之基隆河初期治理 工程整治範圍,從上游之基隆市八堵暖暖橋至台北縣市交界之南湖大橋,全長23 公里,研究範圍面積共約60 平方公里。初期計畫方案係以河道疏浚為主要整治工程,期以能通過10 年重現期之洪水量為目標,本研究依該地區之水理特性,結合一維河川變量流模式與二維漫地流淹水模式,建立基隆河流域整治段河川主流與洪水平原間之互動式二維地表淹水模式,以了解河川主流與洪水平原漫地流間隨水位高低之變化而產生之互動關係。在河川變量流模式方面,係以一維動力波方程式為基礎,利用非線性完全隱式差分法建立模式;二維漫地流淹水模式則以二維零慣性模式為底礎,利用交替方向顯式差分法建立模式。河川主流與洪水平原漫地流之水位互動,則考慮河川一洪水平原之內外水位差,依自由堰或潛沒堰公式計算。研究中並針對初期計畫方案,進一步模擬瑞伯、芭比絲、象神颱洪等事件對研究地區之淹水境況,以探討整治河段疏浚後之改善程度,本研究選定87 年瑞伯颱風與芭比絲颱風及89 年象神颱風等三場颱洪事件之淹水資料作為模式之驗証,以數值模式為演算工具,期有效正確地完成淹水境況模擬,研究成果可提供有關單位訂定防洪措施之參考。 Metropolitan Taipei is located in Taipei basin where is densely populated. Tansui River and its tributaries, Hsindan Creek, Tahan Creek, and Keelung River run through it. Due to the topographic characteristics in the basin, the lowlands along Tansui River and its tributaries were frequently inundated. As a result the Central government has conducted the Taipei Flood Prevention Project to reduce the flood risk since 1982. According to the project, the levees with 200-year protection level were exhaustively constructed alone the Tansui River and its tributaries to confine flood flow and prevent inundation disaster except the upstream region of Keelung River like Shiji-Wudo, Zuifan town of Taipei County, and Chidou, Nannan district of Keelung City. Fast economic development in those region increase flood risk. Serious inundation disasters occurred in Shiji-Wudo area along Keelung River in 1998. On the other hand, the area along Keelung River in the portion of Taipei City was safe during Typhoon Zeb event since it is protected by 200-year levees. Overbank flooding from Keelung River mainly influences inundation in Shij i-Wudo area. Therefore, it is necessary to investigate the relationship between channel flow in rivers and overland flow in floodplains, especially the flow stage interaction. The project belongs to the NSC three-year integrated project entitled ¡§Inundation Scenario Simulation and Decision Support System for Flood-Damage Mitigation in Pilot Areas (I)¡¨ as its 7th subproject. The main objective of this study is to simulate the interaction between flooding and inundation of Shiji-Wudo area where is under the short-term project of channel improvement for 10-year protection level managed by Ministry of Economic Affairs. The study area, starting at Nannan bridge of Keelung City and ending at Nanhui bridge of Taipei County, is 23 kilometers long and its floodplain is 60 square kilometers. A two-dimensional flooding/inundation model associated with dynamic interaction between channel flow in rivers and overland flow in floodplains will be developed in the project. In the simulation, a two-dimensional inundation model is used to simulate overland flow in floodplains, whereas a one-dimensional river routing model is adopted for channel flow using nonlinear finite difference method. The dynamic interaction between Keelung river and its adjacent floodplains is computed based on the difference between river stage and inland water stage, and is taken into account in the model simulation by using the weir or orifice formula. The two-dimensional inundation model is based on the zero-inertia concept for computation of inundation zones and depths. The effectiveness of the short-term project is also evaluated. Typhoon Zen and Babs in 1998 and Xangsang in 2000 are used for model verification. The results of inundation scenario simulation can be used for flood mitigation measure and decision support system for government agencies. |
URI: | http://ntur.lib.ntu.edu.tw//handle/246246/10713 | 其他識別: | 892625Z002060 | Rights: | 國立臺灣大學生物環境系統工程學系暨研究所 |
顯示於: | 生物環境系統工程學系 |
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892625Z002060.pdf | 3.15 MB | Adobe PDF | 檢視/開啟 |
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