行政院國家科學委員會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(Ⅲ)

The study serves as the 7th subproject of the NSC three-year integrated project entitled ¡§Inundation Scenario Simulation and Decision Support System for Flood-Damage Mitigation in Pilot Areas (ifi)¡¨. The main objective of this subproject 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 flood protection level and the long-term project of flow divergence at Yuanshanzi, managed by Ministry of Economic Affairs. This three-year subproject started in 2000 and ended in 2003. In the first year, a two dimensional flooding inundation model associated with dynamic interaction between channel flow in rivers and overland flow in floodplains was developed in the project. A two-dimensional inundation model based on the zero-inertia concept for computation of inundation zones and depths was used to simulate overland flow in floodplains, whereas a one-dimensional river routing model was adopted for channel flow using nonlinear finite difference method. The dynamic interaction between Keelung River and its adjacent floodplains was computed by using the weir or orifice formula, according to the difference between river stage and inland water stage. The effectiveness of the short-term as well as long-term projects is evaluated in the second and third year of this three-year project, respectively. Typhoon Zen and Babs in 1998, and Typhoon Xiansan 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 govermnent agencies.本計畫為三年期整合型計畫「防洪示範區淹水境況模擬與決策支援系統之研究（三）」之子計畫七，其主要目的在於探討基隆河治理工程範圍中，在不同降雨條件下之淹水境況。研究係依據經濟部基隆河治理推動小組所提出之基隆河初期與長期治理工程方案，分別探討初期與長期整治方案對汐止、五堵等地區之影響程度。初期計畫方案以河道疏浚為主要整治工程，以能通過十年重現期之洪水量為目標，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；而長期整治方案則以「員山子分洪計畫」為探討對象”本計畫分三年度（89 年至92 年）完成，第一年計畫已於90 年執行完畢，其目的係建立基隆河流域整治段河川主流與洪水平原（汐止市區）間之互動式二維地表淹水模式，模擬河川主流與洪水平原漫地流間隨水往高低而互動之關係，模式以87 年瑞伯、芭比絲颱風及89 年象神颱風事件來進行檢定、調整與驗證，並繼而探討基隆河流域整治段在遭受上 台灣大學生物環境系統工程學系在十年重現期護岸及員山子分洪計畫完工後之各重現期降雨之淹水境況模擬，並考慮汐止市區建物及街道之影響，完成基隆河流域整治段中洪水瓶頸地區之「主流一洪水平原（汐止市區）」二維動態淹水分析。此外，第三年並同時整合基隆河流域整治段之淹水災害棋擬資料。應用於本研究計畫之成果可做為子計畫九「基隆河流域淹水損害評估模式與相關資料庫建立之研究」及子計畫十「基隆河流域防洪決策支援系統之研發」之依據