逕流污染屬於非點源污染的一種,其中暴雨初期沖刷含有大量高濃度的汙染物,對於河川水質的影響甚鉅,難以利用人工的方式即時監測及控制。本研究的目的在於規劃一自動化逕流污染控制系統,並選擇台北市六館抽水站幹線系統為對象進行模擬,來了解各種暴雨條件對淡水河之影響,以及模擬操作該自動化控制系統之效率。 在模擬案例方面,本研究選擇美國環保署所發布之SWMM模式,經率定後輸入降雨頻率(2、5、10、25及50年)、降雨延時(60、90、120分鐘)、晴天日數(7、14天)等資料,模擬下水道系統之水理及水質。模擬結果發現影響暴雨初期沖刷污染物SS之主要降雨因素依序為:晴天日數(antecedent dry weather period)、降雨延時(rainfall duration)、尖峰降雨強度(maximum rainfall intensity)及其所發生之時間、降雨頻率(rainfall frequency)。此外利用質量平衡的方式針對淡水河基流量Q75及Q90兩種情況進行河川水質之模擬。研究結果顯示該逕流污染控制系統在案例模擬中能夠達到削減非點源污染排入承受水體之目標。 建立該自動化逕流污染控制系統,能將大量的人工採樣、監測資料及相關的管理工作予以簡化,提高非點源污染之控管成效,對生態環境及國家競爭力均有正面之貢獻。
First flush resulting from urban surface runoff is recognized as one of the major causes of quality deterioration in the receiving water bodies. Accordingly, an auto-control system is planned in this study to manage the runoff pollution in a real-time control in an urban drainage system. To understand the first flush phenomenom and to simulate the controlling efficiency, an auto-control system has been constructed. The storm water management model was employed to simulate runoff quality and hydrography for Liuguan in Taipei. The input conditions include different rainfall frequency (2, 5, 10, 25 and 50 years), rainfall duration (60, 90 and 120 minutes) and antecedent dry weather period (7 and 14 days), which were found to be the most important parameters influencing the first flush load of suspended solids. Moreover, the mass balance equation is used to calculate the water quality of the receiving water bodies. The results of simulations show that the auto-control system could effeciently reduce the nonpoint pollution which discharges into the receiving water bodies.