利用WASP推估河川涵容能力及研擬管理策略-以屏東縣武洛溪為例

Estimation of Assimilative Capacity and Elaboration of Control Strategies for the Wuluo River in Pingtung County Using WASP

侯嘉琦(Jia-Ci Hou)

指導教授 ： 黃益助

國立屏東科技大學/工學院/環境工程與科學系所/碩士(2016年)

摘要

武洛溪流域為高屏溪下游支流，是高雄地區重要的水源之一，承受來自於屏東地區之工業廢水、畜牧廢水及生活污水。自從政府推動高屏溪上游養豬業的離牧政策後，大批養豬業者遷徙至武洛溪流域，對水體造成嚴重的污染。流域內畜牧和養殖場數量繁多，且為了降低成本而採行集中飼養，豬隻都被高密度地關在水泥豬圈中，也常發生廢污水未經處理便排放至武洛溪之偷排與暗管事件，使得污染排入量遠超過河川自淨能力負荷量，故行政院環保署將武洛溪列為重點整治河川之一。
本研究應用Water Quality Analysis Simulation Program (WASP)建立武洛溪水質模式，對武洛溪流域進行水文水質之採樣監測及記錄，分析結果用於評估河川現況，並以分析之數據建立水質模式，模式建立完成後，利用平均絕對百分誤差法(Mean Absolute Percentage Error, MAPE)進行評估，結果顯示大部份水質模擬成果都在可接受的範圍內，可用於武洛溪流域水體水質之預測。
儘管武洛溪流域曾設置人工濕地等改善工程以淨化水質，但濕地於2009年時遭八八風災摧毀，所以須建立另一套完善的改善策略，以利提升水體水質。本研究進行河川涵容能力污染削減量分析，結果得知NH3-N及BOD所需削減率都偏高，整體削減率分別至少需達93.97 %及77.01 %，方可改善水體水質至丙類水體標準。模擬加強管制與設置豬廁所後，推估SS可達丙類水體標準，而BOD及NH3-N整體削減率各達71.23 %及87.41 %時，方可達丙類水體標準。而實施沼渣沼液作為農地肥分使用改善策略後，SS將有望達乙類水體標準，但BOD和NH3-N尚需削減42.03 %及76.38 %才可達丙類水體標準。但要是設置養豬專區，將散戶養豬業者集中，使下游地區得以施行沼渣沼液作為農地肥分使用的話，位於武洛溪末端處的BOD含量將可達丙類標準，但以總流域來看，BOD和NH3-N尚需削減6.83 %及65.95 %才可達至丙類水體標準。由上述的改善策略可發現，新舊的整治政策都可以使武洛溪流域下游水質得到一定的淨化效果，尤以沼渣沼液作為農地肥分使用成效較為顯著。本研究結果可做為日後有關單位對武洛溪水質管理策略研擬及改善成效預測參考。
關鍵字：武洛溪流域、水質模式、WASP、污染削減量、管理策略

關鍵字

武洛溪流域 ； 水質模式 ； WASP ； 污染削減量 ； 管理策略

並列摘要

The Wuluo River basin converged in the downstream of Gaoping Rive is an important source of potable water in Kaohsiung area. It bears the discharges of industrial, livestock, and municipal wastewaters from the Pingtung area in Taiwan. Since the government has promoted the policy to downsize the concentrated animal feeding operations from the upstream of Gaoping weir, a large number of pig industry migrated to the Wuluo River basin that caused serious water pollution. A large number of livestock and aquaculture exist in the basin. Centralized pig breeding is adopted to reduce the costs. Improper treated wastewater was often illegally discharged into the Wuluo River through the underground pipes, so that the amounts of pollutant loadings discharged far exceeded the river self-purification capacity. Taiwan Environmental Protection Administration (EPA) is working on the key control and remediation of the Wuluo River.
In this study Water Quality Analysis Simulation Program (WASP) is utilized to establish the water quality model of Wuluo River. Hydrological surveying and water quality monitoring was conducted. The analysis results were used to assess the water quality of the river concerned and as input data to develop the water quality model. After the completion of the model establishment, results were evaluated by the mean absolute percentage error (MAPE) method. The results showed that the majority of water quality simulation outcomes are within the acceptable range, it could be used for prediction of water quality improvement with the proposed management strategies.
Although the Wuluo River basin had been set up artificial wetlands to purify the water quality, the wetlands were severely destroyed by typhoon Morakot in 2009. Therefore another comprehensive improvement strategy must be established to enhance the water quality. The present study was conducted the analysis of river assimilative capacity and pollution reduction, the results showed that NH3-N and BOD were required at least for an overall reduction rate of 93.97 % and 77.01 % to improve the water quality to Class C standards regulated by Taiwan EPA. For the scenarios of enhanced control and pig toilet installation, the estimated SS could reach the Class C water quality standard, while BOD and NH3-N must be reduced up to 71.23 % and 87.41 % to meet the Class C water quality standard, respectively. After the implementation for use of fermented residues and liquid as farm fertilizers, the estimated SS could reach Class B water quality standard, while BOD and NH3-N still needed to reduce 42.03 % and 76.38 % to meet the requirements of Class C water quality standard. If pig feeding zones are set up to centralize the pig industry with fewer number of pigs for better management, and to implement the fermentation residue and liquid as farm fertilizer. The BOD concentration located at the downstream of Wuluo River could meet the requirement of Class C water quality standard. But for the watershed, BOD and NH3-N still need to reduce at least 6.83 % and 65.95 % to meet the requirements of Class C water quality standard, respectively. From the above-mentioned proposed management strategies, previous and present remediation policies can improve the downstream water quality of Wuluo River basin to a certain extent, especially for the use of fermented residues and liquid as farm fertilizers. The results of this study can provide as a reference for authorities to elaborate the water quality management and improvement strategies of Wuluo Riverin the future.
Keywords：Wuluo River, water quality model, water quality analysis simulation program (WASP), pollutant reduction amount, management strategies

並列關鍵字

Wuluo River ； water quality model ； water quality analysis simulation program (WASP) ； pollutant reduction amount ； management strategies

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