中文摘要:

  石門水庫自民國53年完工迄今已近半世紀,近年來不論水體混濁度及水質優養化問題,皆對水庫的供水造成很嚴峻的考驗。本計畫主要針對水質優養化問題為改善石門水庫水質的主要目標,探討污染源並提出短期可行之污染削減方案。另外,本計畫亦針對採用課徵清潔費的方式,作為環境管理經費來源之可行性進行評估。依照環保署之要求,本計畫亦協助舉辦一場BMP研討會。

  計畫成果包括下列:(1)石門水庫集水區近年水質均介於普養至優養化狀態,並以總磷為主要影響因子。造成污染的熱點為水庫周邊的三民溪、湳仔溝,及山坡地大規模旱作區等。(2)總磷污染中,點源污染與非點源污染的比例約15:85。人為活動中,以旱地佔非點源污染來源的32%最多,顯示人為活動所產生的污染必須被妥善管理。(3)生活污水所造成之點源污染,應以建構完善的基礎設施為優先削減方案,如污水下水道、現地淨水設施等。遊憩觀光所造成的污染,則可從變更旅遊方式著手,提倡低衝擊旅遊,以減低遊客帶來的污染衝擊。(4)非點源污染的最主要來源為作物的過量施肥與暴雨所造成的表土沖刷,應分別從肥料最佳化管理及水土保持方面著手。必要時可加以設置結構性最佳管理作業(BMPs),並建議設置於水庫周邊熱點,同時監測其削減成效。(5)就現行法規而言,石門水庫課徵清潔費並無直接且立即可遵循之法源根據,本計畫目前僅依不同之污染來源,列舉較為相關之法條,未來若要課徵,應先確立課徵對象,並進行修法及作進一步評估。(6)BMP國際研討會中,國外教授提供了美國環保署在非點源污染部分的管理方法,並建議水庫、流域應以總量管制方式進行管理,值得國內未來水庫管理上之借鏡。

 

英文摘要:

Shihmen Reservoir has been operated in nearly half of a century since 1964. In recently years, it caused severe situations for water supply regardless of high water turbidity, as well as the problem of eutrophication of water. The main purpose of this project is to improve the water quality, especially for the eutrophication problems of Shihmen Reservoir. The short-term viable strategies for diminishing pollutants are proposed in this project by researching into the sources of pollution; moreover, the feasibility of management founding by levying clean fee are assessed. According to the demand of EPA, this project also helped to organize a BMP conference.

The results of this study are: (1) the water quality of Shihmen Reservoir was at the mesophication to eutrophication levels in recent years, and the total phosphorus (TP) as the main factors involved. Moreover, the watersheds around Sanmin River and Nanzi Ditch closed to the reservoir and the massive agriculture fields on the hillsides are the hot spots to contribute pollution. (2) The loading ratio of point source pollution to non-point source pollution (NPS) is evaluated to be 15:85 for the pollution of the total phosphorus. The non-point source pollution, 32%, caused by human activities mostly comes from dry farmlands. It pointed out that the pollution caused by human activities must be managed properly. (3) Reducing the point source pollution emitted from the domestic sewage should be based on building the sound infrastructures as a priority programs, such as construction of wastewater sewer systems and establishment of on-site water purification facilities. Furthermore, to promote the low-impact travel can effectively reduce the pollution caused by tourists. (4) Excessive fertilization of crops and surface soil erosion caused by rainstorm are the major source of non-point source pollution. It is effective to practice the optimization of fertilizer management and soil-water conservation to reduce pollution. The structural best management practices (BMPs) can be carried out at hot spots when necessary and they are suggested to set up at the hot spots around the reservoir, as well as monitor the effectiveness of their reduction. (5) In the current lows, there are no laws can be followed directly and immediately to impose cleaning fee for Shihmen Reservoir. The more relevant laws are listed in this study according to different resources of pollution. However, it should first be established by the objects levied and amending the laws for the next stage. (6) Professor introduced the management directions of US EPA for non-point source pollution control in this BMP international conference. Moreover, the Total maximum daily load (TMDL) of pollution was proposed for the reservoirs and watersheds managements.