圖書典藏及影音數位平台

臺北水源特定區位於大臺北都會區東南隅近郊，轄區面積達717平方公里，為新北市面積1/3。轄內包含北勢溪（翡翠水庫）集水區及南勢溪集水區，兩溪於新店龜山匯流為新店溪，而新店溪之青潭堰為大臺北地區的主要自來水來源，其水源水質水量之安全與潔淨將直接影響大臺北地區500萬人的用水品質，過去20多年來因應水源政策，水質水量管理尚稱良好，提供了質優量豐的水源，確保了大臺北地區用水無虞。 惟近年來北部地區公共用水需求成長，故採區域間水源調配，未來新店溪水源將取代部分大漢溪水源，供給板新地區用水，供水人口將逐步提升至超過650萬人，一般而言，當供水量越大，表示缺水的風險越高，對於水文觀測之掌握就更為重要。再者，依據台灣水文觀測長期發展計畫，高流量觀測能量不足為河川流量觀測之重要議題，且高流量通常伴隨著高濁度狀況發生，故實有必要進行流量觀測技術之探討與精進。 又監察院近來亦關注本局轄內南勢溪上游東札孔溪崩塌議題，並要求本局持續加強監測機制。雖本局已於南勢溪福山及攬勝橋設置自動濁度監測站，惟101年蘇拉颱風造成強降雨，挾帶大量泥沙，造成本局大林橋測站監測儀器遭沖刷流失需另斥經費修復，而遭審計部要求檢討改進，故本局暫行作法除於颱風前後加強檢視固定情形外。並於陸上警報發佈後暫停即時監測作業，委請儀器廠商赴現場取出水質儀器，俟颱風過後再行安裝，以保全儀器。此作法雖可保全儀器設備不受損壞，惟高流量高濁度之重要監測資料無法取得。實有研擬替代方案之必要，故擬於本計畫進行本局福山及攬勝橋水質測站於高流量下濁度觀測之方案評估及建議，以獲取高流量下之即時濁度資料。 國內外與中國大陸皆對流量觀測相當重視，流量觀測方法眾多，各種觀測技術之原理、計算、操作方法與適用性並不相同，且臺北水源特定區內河川特性水文水理條件亦有所差異，故擬透過本計畫進行流量觀測方法與技術規範蒐集，進行觀測方法之精度與不確定性分析，再透過試驗室測試與現地觀測之比測分析，對於觀測方法的適用性進行探討，並就本局轄內7處定期流量觀測場所進行現勘，擇其中3處進行現地比較測量，以提出最適觀測方法，並就臺北水源特定區水文長期趨勢進行分析，對未來水量供給進行風險評估，最後，依整體執行經驗辦理兩岸水文技術交流。

Whole the hydrological information of the Area Protected by the Taipei Water Management Office, which included the conditions, time, method of flow discharge measurement, were collected in this report. The instruments, theory and measured methods for flow velocity, water depth and water level in different flow conditions of Taiwan, Mainland China and other countries were also collected and arranged. Whole existing water flow stations managed by the Taipei Water Management Office were evaluated by ten parameters. It showed that the position and condition of whole existing water flow stations were nice choice to be a water flow station. In the lab experiment, the measured error of price flow meter will be smallest if the instrument could keep on constant direction and the moving velocity of the trolley loading flow meters was between 1.0 and 3.0 m/s. Therefore, price flow meter was suggested for the reference if the measurement position was on the bridge and flow velocity between 1.0 and 3.0 m/s. The measured error of electromagnetic flow meter was smallest if the moving velocity of the trolley was smaller than 1.0 m/s, so it was suggested to use on the artificial wading measurement. The measured error of propeller flow meter was smallest if the moving velocity of the trolley was bigger than 3.0 m/s. It could get well measured results by Continuous Wave Radar (CW Radar) when the depression angle was set between 20° and 50°. Larger uncertainty of measured results might happen if measured by propeller flow meter, electromagnetic flow meter and ADV on natural rivers with turbulent flow condition. The error could be diminished by measured many times. Based on the measured results of the high surface velocity condition (4.6 m/s), it could verified that CW Radar could be used to measure the surface velocity during typhoon even. The oscillation of the transient velocity measured by Acoustic Doppler Current Profiler (ADCP) was obviously. Mean velocity of the measured results during a span (40 sec) was close to that measured by price flow meter, so it suggested that that the mean velocity should be used to install of the transient velocity measured by ADCP to avoid the oscillation and decrease the error of the measured velocity. The variation tendency of suspended concentration measured by automatic instrument set on Fu-Shan water flow station was close to the variation of water level when water level was higher than 284m during typhoon even. Based on the artificial-sampling results on Lan-Sheng Bridge, the regression formulas between turbidity and suspended-load concentration for different typhoons would be close if the biggest discharge of typhoons could be considered to conversion the suspended-load concentration of different typhoons. The regression formula got by whole artificial-sampling results in this study could be used to evaluate the real relationship between turbidity and suspended-load concentration for different typhoon even on Nan-Shi River. The turbidity of Nan-Shi River could be calculated by the automatic-measured concentration of suspended load on Fu-Shan water flow station and the regression formula.