圖書典藏及影音數位平台

本次計畫係針對近年來臺中市都市發展迅速，集水區內有多處 開發案，如臺中市第14期市地重劃區與臺中市第13期市地重劃區及中下游為多處市地重劃區等，集水區內的土地利用情形已大幅改變，與92年經濟部水利規劃試驗所辦理「台中地區柳川排水及土庫溪排水系統改善規劃」內容略有不同，有必要針對轄區排水系統進行全面性地文及水文環境生態進行檢討，同時針對潭子外圍截水道之截流量進行規劃檢討，以瞭解現況排水路特性，並提出改善規劃方案及管理建議，供工程單位實施之依據，以降低減少淹水問題，促進社會繁榮。

Liu Drainage is originated nearby Shi-hshui-ko River of the south coast of Da-jia River. It flows through Fong-yuan, Tan-tz and urban area of Taichung City, and converged into Han River on Wu-jih district. Tuku Drainage is originated from north of Tan-tz. It flows through Tan-tz, Pei-tun District and urban area of Taichung City, and converged into Han River on Wu-jih district. Seeing that original management projects up to now are over 10 years, surroundings, Channel status have changed. Therefore, it is necessary to review the original management projects and plans. Liu Drainage and Tuku Drainage are all located in Taichung Basin. The channel widths of Liu Drainage are between 7.5 to 26 meters, the channel widths of Tuku Drainage are between 15 to 36 meters. The watersheds of Liu Drainage and Tuku Drainage cover high development and utilization district in Taichung City, the population reached to 1,736,332 persons. Socio -economic status are mainly the manufacturing, wholesale and retail trade, industrial and commercial services, etc. It used the rainfall data of Taichung, Fong-yuan, Jyu-sing farm. Ka-li, Cao-hu, and Shuei-jyue-tou rainfall gauge stations for rainfall analysis. The rainfall frequency analysis via Pearson Type III(PT3) Distribution to analyze the storm of yearly maximum 24 hours in every recurrence (return period, TR). Then, according to Triangular unit hydrograph Method, Instantaneous unit hydrograph and Rational Formula with the 24 hours rainfall type to analyze the peak-flow of yearly maximum 24 hours in every recurrence (return period, TR). After comprehensive comparison, the results of this project were less than preliminary results. In view of increased rainfall and security, It adopted preliminary analysis results. The Hydrocomp Simulation used HEC-RAS to perform 1D hydraulic calculation. According to analysis results, the channels of Tuku Drainage all met of protect standard in TR=10 yr. Most channels of Liu Drainage met of protect standard in TR=10 yr, except that upstream of Syue-shih-liu Bridge nearby China Medical University, San-sin Bridge to Long-tou Bridge, Fu-heng Bridge to Yuan-tong Bridge, Tan-bei Bridge to Siang-he Bridge in Tan-tz district can’t met of protect standard in TR=10 yr. According to the resultsof two-dimensional hydraulic Simulation via Sobek, the higher potential flood areas included upstream regions of Liu Drainage(nearby Tan-tz and Pei-tun District), and part channels of Tuku Drainage. For instance, the flooding range in TR=10 yr is 42 hectares. According to the drainage planning principle, site survey & questionnaire and hydrological analysis review, the drainage planning include channel governance, flood wall, flood diversion, etc. Relevant major improvement engineering include the Tan-tz Diversion Tunnel reduced 66 cms based on the original management project, the Tai-yuan Rd. Diversion Tunnel setting a channel to reduce 30 cms to Liu Drainage, keeping Si-chung Rd. backflow Tunnel, building flood walls on part channels can’t met of protect standard in TR=10 yr. The engineering cost of Liu Drainage and Tuku Drainage is 7.299 billion NT. Dollars, The ratio of benefit to cost is 1.07.