吳先琪臺灣大學：環境工程學研究所陳怡靜Chen, Yi-JingYi-JingChen2007-11-292018-06-282007-11-292018-06-282004http://ntur.lib.ntu.edu.tw//handle/246246/62603磷是水生物重要營養鹽，近年來台灣水庫總磷濃度升高受到大眾關注，需瞭解影響水庫磷的內、外部負荷之重要機制及因子，進行改善。本論文以亞熱帶深水水庫－德基及翡翠水庫為研究對象，探討集水區人為活動、水文變化造成之水庫密度流及生物地質化學作用對水庫磷的傳輸及流布影響。 應用磷的化學分選方法及地化模式模擬於翡翠水庫底泥及土壤研究得知，翡翠集水區原生磷礦物是鋁結合磷，但受到坪林隧道工程棄土及地下湧水引入之鈣結合磷及鈣離子濃度影響，底泥磷物種組成改變，孔隙水磷濃度降低，遂降低磷內部負荷。德基集水區釋出之溶解有機磷佔總磷量30%，1998年之後地表逕流水中溶解有機磷降低是德基二角多甲藻(Peridinium spp.)優勢消失的重要因子。 本研究依據現地採集數據，發展納入底層水溶氧、底層水溫、垂直向紊流擴散、生物反應及底泥主要含磷礦物溶解沉澱平衡動力等機制於底泥傳輸及通量模式(2 box sediment phosphorus transport and flux model, 2B-SEPF)中，模擬底泥溶解總磷通量。研究結果顯示，翡翠水庫底泥磷通量顯著受到邊界處之底層水溶氧、水溫及垂直向紊流擴散影響。模擬之底泥溶解總磷負荷和溶解總磷外部負荷相當。然而以CE-QUAL-W2二維水理水質模式模擬結果，翡翠水庫年初表水總磷濃度突增主要是受到冬季冷水密度流造成的水體抬升及前一年停留在中層水之磷外部負荷聯合貢獻結果，相對地磷內部負荷雖可被抬升至中層水處，對表水的貢獻有限。 本論文發展出深水攝影暨現地示蹤劑實驗技術，有助於更準確模擬底泥磷通量。茲於翡翠水庫底泥－水界面處實驗，示蹤劑煙團變化配合高斯分布理論推求出水底部垂直紊流擴散係數約為0.3-2.5 cm2/sec。以翡翠水庫發生高濁度引起的異重流時水中濁度隨時空之變化做為天然示蹤劑，有助於模式解析翡翠水庫水理及磷傳輸動態。所推估出翡翠水庫縱向水體延散係數， 為0.188 至0.493 m2/sec，垂直向延散係數， 為 0.11 cm2/sec。 綜合結論，整合磷的內、外部負荷所發展之底泥連結水質模式 (2B-SEPF 和CE-QUAL-W2 模式)配合水下攝影暨示蹤劑技術，可有效預測水體磷的宿命。磷的化學分選技術及地化模式應用可協助釐清磷的生地化作用受到人為活動影響及磷與藻類消長之關係。它們將有助於回溯可能污染磷源進行有效的集水區管理，用於下游淨水廠水質處理規劃策略參考以維護用水品質及大眾健康。Recently, the concentrations of total phosphorus (TP) in the reservoirs in Taiwan have increased at a rate sufficient to cause public concern. The understanding of the mechanisms and factors influencing both the external and internal P input in the reservoir is needed. The objective of this research was to evaluate the integrated effect of hydrological processes, biogeochemical processes of P and the human activities in the watershed on the fate of P in the reservoir. The study areas include both the Techi Reservoir and Feitsui Reservoir, respectively. The chemical P fractionation and geochemical simulations in the sediments and surface water were used to clarify the speciation of P forms in order to verify the source of P in the watershed. The results showed that the distribution of P forms in the sediments in Feitsui Reservoir had been affected by the Ca or Ca bound P export from the debris from tunnel construction and groundwater inflow in the watershed, subsequently influencing the chemical composition of porewater and the internal loads of P. Dissolved organic P in the surface runoff from the Techi watershed, accounting for 30 % of TP, was the major source of P serving for the prosperity of the dominant algal species, Peridinium spp., in the surface water. A sediment P transport model (2 Box-Sediment Phosphorus Transport and Flux Model, 2B-SEPF), which considers the sediment water interaction (vertical turbulent diffusion, overlying water temperature difference, overlying dissolved oxygen difference), microbial reaction and precipitation-dissolution dynamics of P minerals, has been developed and verified. The predicted internal dissolved total phosphorus (DTP) loads was almost equal to the external DTP loads in Feitsui Reservoir, a subtropical and deep reservoir. However, the water quality simulation results by CE-QUAL-W2 model revealed that the hydrologically induced density currents in winter together with the external loads of P were the main cause of the surface water quality deterioration, even though the bottom water carrying abundant P internal loads might be lifted to the middle layer by the water momentum force by the density current. The apparatus of the in-situ tracer experiment integrated with a submerged video camera was developed in this study. The estimated vertical turbulent diffusion coefficient,εz , at the sediment water interface with a depth of 85m at dam in Feitsui Reservoir was in the range of 0.3-2.5 cm2/sec. It makes the prediction of the sediment P flux more accurately. The spatial and temporal variations of the suspended solids (SS) brought in by the turbidity currents were also used to estimate the horizontal and vertical dispersion coefficients in the reservoir by applying the Gaussian distribution theory. They were useful for predicting the hydrodynamics and transport of P in the reservoir. In summary, the integrated sediment–water simulated model (2B-SEPF and CE-QUAL-W2 model) could be a useful tool to predict the fate of P in the reservoir with complex hydrological problems like density currents. The chemical P fractionation and geochemical simulations techniques could be used to clarify the effects of human activities on the biogeochemical processes of P and the linkage of P species with the speciation of algae. They are also useful for the BMP management in the watershed and the downstream water treatment planning for public health.目錄 中文摘要 英文摘要 目錄 i 圖目錄 v 表目錄 viii 符號說明 ix 中文摘要 xii 英文摘要 xiv 第一章 前言 1-1 1.1 研究動機與目的 1-1 1.2 研究內容 1-2 第二章 集水區入流磷型態、釋出來源及水庫磷的質量平衡與其對水體優勢藻種消長可能影響 2-1 2.0前言 2-1 2.1文獻回顧 2-1 2.1.1水庫湖泊磷的循環 2-1 2.1.2集水區出流磷的種類及釋出來源 2-4 2.1.2.1集水區出流磷的分選 2-4 2.1.2.2磷與懸浮固體 2-5 2.1.2.3磷與水文循環 2-7 2.1.3集水區磷的外部負荷推估 2-7 2.1.4水生物地域變化 2-8 2.2研究場址背景 2-9 2.2.1地質與土壤 2-9 2.2.2氣候與水文 2-11 2.2.3歷年水質監測 2-12 2.3材料及方法 2-12 2.3.1整合底泥-水環境之磷質量平衡模式 2-12 2.3.2水體環境磷的型態分類 2-14 2.2.3集水區生物可利用磷釋出率 2-15 2.3.4採樣與分析方法 2-16 2.3.4.1水樣品與土壤樣品採集 2-16 2.3.4.2磷的分析方法 2-21 2.4結果與討論 2-23 2.4.1集水區出流磷的型態分析結果 2-23 2.4.2集水區主要磷來源與平時出流水質特性 2-23 2.4.3生物可利用磷佔總磷比例、型態變化與水體中優勢藻種消長關係 2-30 2.4.4集水區生物可利用磷釋出率(Bio (P))評估 2-37 2.4.5翡翠水庫的質量平衡估算 2-38 2.4.5.1水庫外部負荷推估 2-38 2.4.5.2水庫底泥沉積量 2-41 2.4.5.3水庫內部負荷推估 2-42 2.4.5.4水庫磷質量平衡確認 2-42 2.4結論 2-44 第三章 磷的生物地質化學作用對底泥孔隙水溶解磷濃度影響 3-1 3.0前言 3-1 3.1文獻回顧 3-1 3.1.1底泥固相磷的來源 3-1 3.1.2底泥固相磷的分選 3-3 3.1.3水中懸浮固體的沉降與掩埋 3-4 3.1.4底泥磷的生物地質化學作用 3-5 3.1.4.1底泥微生物的影響 3-5 3.1.4.2底泥酸鹼值(pH value)及氧化還原電位(oxidation-reduction potential) 3-6 3.1.4.3底泥無機磷礦物的溶解與沉澱化學平衡 3-7 3.1.4.4底泥磷的吸脫附 3-7 3.2材料及方法 3-8 3.2.1現地地化環境描述 3-8 3.2.2現地底泥、孔隙水及土壤採樣與物化性質分析 3-9 3.2.3底泥與集水區土壤固相磷、鐵、錳、鋁及鈣分選 3-13 3.2.4預測平衡態的孔隙水溶解性磷濃度(EPC)與釋出指標SCRI 3-14 3.3結果與討論 3-17 3.3.1翡翠水庫底泥及土壤固相磷分選 3-17 3.3.2主要底泥固相磷物種之確認 3-20 3.3.3磷及相關金屬離子在集水區環境中可能的地化循環 3-20 3.3.4水生成磷礦物之探討 3-29 3.3.5底層水溶氧及水溫對底泥磷釋出能力之影響 3-32 3.3.6陸生鈣及鈣結合磷輸入對底泥孔隙水磷濃度影響 3-37 3.4結論 3-40 第四章 底泥磷的傳輸及底泥-水邊界處磷釋出機制研究 4-1 4.0前言 4-1 4.1文獻回顧 4-1 4.1.1底泥固相磷的傳輸 4-1 4.1.2底泥孔隙水溶解磷的傳輸 4-2 4.1.3影響底泥-水邊界處的磷釋出機制 4-2 4.1.3.1底泥-水邊界層溶氧及鐵離子 4-2 4.1.3.2底泥-水邊界層的質傳阻滯 4-3 4.1.4底泥磷模式發展現況 4-5 4.2材料及方法 4-8 4.2.1一維底泥磷的二層傳輸通量模式2B-SEPF 4-8 4.2.1.1模式概念及基本假設 4-8 4.2.1.2統御方程式 4-11 4.2.1.3模式邊界條件與磷釋出通量 4-13 4.2.2底泥磷釋出通量管柱實驗(好氧及無氧環境) 4-16 4.2.3現地實測底泥上層水溶氧、總磷、反應性磷及水溫隨時間變化 4-18 4.2.4底泥-水界面的示蹤劑實驗 4-18 4.3結果與討論 4-21 4.3.1底泥磷釋出通量管柱實驗結果 4-21 4.3.2現地實測底泥上層水溶氧、總磷、反應性磷及水溫隨時間變化 4-26 4.3.3底泥-水界面示蹤劑實驗結果 4-28 4.3.3.1冬季於上游斷面底部施放示蹤劑實驗 4-28 4.3.3.2夏季於大壩底部施放示蹤劑實驗 4-29 4.3.4預測底泥磷通量 4-33 4.3.5底泥模式參數的敏感度分析 4-33 4.4結論 4-47 第五章 異重流形成與翡翠水庫水質變化之關係及延散係數推估 5-1 5.0前言 5-1 5.1文獻回顧 5-2 5.2材料與方法 5-4 5.2.1現地觀測濁度流隨時間的變化 5-4 5.2.2濁度流水理模擬 5-7 5.2.3估計水體延散係數 5-10 5.3結果與討論 5-11 5.3.1觀測濁度流隨時間的變化 5-11 5.3.2預測濁度流運動路徑 5-20 5.3.3 排砂對大壩水質幫助 5-20 5.3.4釐清濁度流對水質影響 5-23 5.3.5估計水體延散係數 5-28 5.3.5.1縱向延散係數 5-28 5.3.5.2垂直向延散係數 5-30 5.4結論 5-30 第六章 集水區人為活動及水文變化對翡翠水庫水體磷濃度之影響 6-1 6.0前言 6-1 6.1文獻回顧 6-1 6.1.1水庫優養化對水質影響 6-2 6.1.2密度流的成因 6-3 6.1.3模擬磷傳輸水質模式 6-4 6.2材料及方法 6-5 6.2.1研究場址背景 6-5 6.2.1.1氣候與水文 6-5 6.2.1.2歷年水質監測 6-6 6.2.1.3近年來翡翠集水區的人為活動 6-8 6.2.2水庫密度流水質模擬 6-8 6.2.2.1模式輸入資料格式 6-8 6.2.2.2模式統御方程式 6-11 6.2.2.3模式輸入檔 6-13 6.2.2.4水質模擬項目 6-13 6.3結果與討論 6-15 6.3.1翡翠水庫歷年水質變化 6-15 6.3.2以CE-QUAL-W2模式模擬水質變化及冬季密度流 6-19 6.3.2.1水理模擬 6-19 6.3.2.2 水質模擬 6-29 6.3.2.3密度流與大壩分層水質變化 6-37 6.3.2.4確認底泥磷內部負荷對大壩表水水質之影響 6-37 6.3.2.5預測集水區磷外部負荷增加對大壩表水水質之影響 6-39 6.4結論 6-41 第七章 總結論與建議 7-1 第八章 參考文獻 8-1 附錄一、底泥磷二層傳輸通量模式2B-SEPF 之數值方程及電腦Fortran程式 附錄二、水體水理水質模式CE-QUAL-W2輸入控制檔(w2_con.npt) 附錄三、檢驗項目之品管查核結果4089322 bytesapplication/pdfen-US密度流生物地質化學作用紊流擴散係數底泥水庫水質模式藻類質量平衡磷sedimentsreservoirbiogeochemical processesdensity currentswater quality modelmass balanceturbulent diffusion coefficientalgaePhosphorus[SDGs]SDG3thesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/62603/1/ntu-93-D87541003-1.pdf