臺灣博碩士論文加值系統

新水庫位於基隆市屬亞熱帶離槽水庫，主要供應基隆及台北都會區用水，由於位置處於溫暖潮濕且降雨量高，以及近年集水區域不當開發而暴雨沖刷營養鹽進入水庫供應水，且新山水庫人為操做進出水，導致近年春季和夏季，新山水庫發生優養化次數增加。
IPCC於2007年發表氣候變遷以經是個可觀察出來不可忽略的問題，且根據(Hsu and Chen, 2002) 對於台灣未來氣候變遷的研究顯示未來不論是雨季還是乾季100年內溫度將上升1.0 至1.4 °C，且對於未來季節性的水文循環更加強化，這將會造成未來水資源供應及對於水質轉變更是有潛在的衝擊，故針對此課題的研究需受關注。
對於IPCC 針對未來預估在氣溫及雨量的變化上可能會影響到河流流量，因此而導致污染物的流動和稀釋，由此可以說明對於水庫的從河川而來的進流會因氣候變遷改變水文循環而導致水質以及水量上的潛在風險，也因為氣溫升高轉變水庫內的化學反應改變水庫水質。
在亞熱帶地區水庫水質惡化的原因以藻類優養問題最為普遍，而其中又以藍綠藻產生的問題最為棘手。 2005 年環保署調查台灣11 座優養水庫之結果也顯示均有微囊藻藻華出現（郭等，2005）。有許多以前的研究表明，微囊藻藻華是最關心和急需解決的問題，在亞熱帶地區，而特別最關注的問題造成微囊藻藻華的條件。這些結果擴大且大部分集中在熱帶和亞熱帶海域的湖泊、水庫，大部分研究顯示優勢藻種為微囊藻，及使水體營養狀況改變，根據大部分研究數據及文獻表示在淡水環境如水庫、湖泊中，一年當中最溫暖的時期，藍綠藻往往依然能夠在水域內成為優勢藻種。 (Liu, 2011; Paerl, 1988; Paerl and Huisman, 2008; Paul, 2008) (Arheimer, 2005; Nõges, 2003; Newcombe, 2012; O’Neil, 2012; Paerl and Paul, 2012; Whitehead, 2009)
由於氣候變化遷是持續不斷的發生，並其對於水庫水資源的持續潛在風險，在新山水庫針對水資源的有效管理以及水質的控制將是不可忽略的議題。
以了解未來水質在氣候變遷下的改變，此論文使用CE-QUAL-W2 模式針對過去新山水庫的歷史資料架設此水庫模式，以及水庫的水理及水質參數的率定及驗證，本研究主要以2004年至2012年，這九年時期數據的收集來進行模式的率定及驗證。對於新山水庫過去的模擬主要是以2004-2008年做為率定年，2009-2012做為驗證年，針對其分別是由於在2009年時新山水庫改變進水策略，除了2009年以上層進水外其他年分皆以下層進水，2009年的進水策略引發營養鹽在上層供給大量藻類生長，該年藻華現象特別嚴重，因此以此年做為分水嶺。針對其模擬水理部分，率定及驗證的水位水溫模擬相當符合實際觀測，而水質部分針對溶氧、總磷、正磷酸鹽、氨氮、硝酸鹽氮、葉綠素a、懸浮固體物進行模擬及其分析結果也都與實測值相當接近。
氣候變遷情境模擬部分，針對已率定好的CE-QUAL-W2模式進行氣象因子的改變，來做為模擬未來氣候變遷下對於於水質的影響。

Hsinshan Reservoir is a subtropical off-channel reservoir located in Keelung city, which supplies water to both Keelung and Taipei metropolitan areas. The limnion layers in this subtropical reservoir turn over twice a year during the spring and fall, inducing eutrophication during the spring and summertime. The objective of this study was three-fold, to investigate possible impacts of climate change on water quality within a subtropical off-channel reservoir. First, develop a two dimensional (x- and z-axes) CE-QUAL-W2 (W2) model to simulate water temperature, dissolved oxygen, nutrients (total phosphorus, orthophosphate, ammonium-nitrogen and nitrate-nitrogen) and Chlorophyll-a (Chl-a). Water quality model results for short-term (2020 to 2039) and long-term (2080 to 2099) future projections were compared to baseline data collected from 2004-2012. Our second objective was to downscale monthly climate change data to a daily time-scale; downscaled data was then input into the W2 model for future projections. The third objective of this study was to assess and discuss implications of exceedance values provided by the W2 model.
Results showed that water surface temperature of Hsinshan Reservoir had a 53.4% probability to exceed 25°C, the temperature at which algal blooms frequently occur. Also, the water temperature profile showed that regardless of future projection, stratification during the summer will be more drastic than the baseline time period. These results suggest that temperature is the driving force affecting the solubility of dissolved oxygen. Decreased levels of dissolved oxygen in turn will increase the release of total phosphorous from sediment layer. In addition to this, total phosphorus and orthophosphate at both the water surface and reservoir bottom are projected to increase, regardless of short- or long-term future projection. Unlike to the baseline time period, total phosphorus at the water surface and reservoir stream bottom has a 22.4% and 2.8% probability to exceed 35 ug/L and 55 ug/L in the future, respectively. Total phosphorous levels at 35 ug/L is the threshold at which eutrophication is defined, thus suggesting water quality in the reservoir will worsen.
Thus, results from this study showed that water temperature, dissolved oxygen and total phosphorous are important water quality parameters affecting projected algal levels of Hsinshan Reservoir. Exceedance probabilities of Chl-a in the long-term future was 4.8 times higher than base period. High concentration of Chl-a, an indicator of eutrophication, is very likely to increase in all projected global climate models.
In conclusion, total phosphorus which affects levels chl-a is the nutrient that limits algal growth. Total phosphorous is a major concern for watershed managers of Hsinshan Reservoir. Stratification causes increased release of total phosphorous from the sediment at the reservoir bottom to the water surface. Mitigated stratification can reduce internal loading of total phosphorous. Therefore, controlling the quantity of total phosphorus internal loading can be an important way to improve reservoir’s water quality and preventing eutrophication.

ABSTRACT i
中文摘要 iii
Acknowledgement v
TABLE OF CONTENTS vi
TABLE INDEX ix
FIGURE INDEX xiii
Chapter 1 INTRODUCTION 1
1.1 Preface 1
1.2 Motivation 3
1.3 Objective 4
Chapter 2 LITERATURE REVIEW 5
2.1 Variability of future climate change projection 5
2.2 Climate change impacts on reservoir water quality in subtropical regions 7
2.3 Climate change potential impact on reservoir water quality in Taiwan 9
2.4 Modeling simulation of the related research 12
Chapter 3 METHODOLOGY 16
3.1 Research framework 16
3.1.1 Background 18
3.1.2 Water temperature and Water quality of Hsinshan Reservoir analysis 21
3.1.3 Climatic characteristics 27
3.2 Data collection 29
3.2.1 Hydraulic data 29
3.2.1 Water quality data 31
3.2.2 Meteorological data 36
3.2.3 Climate change data 38
3.3 Introduction of CE-QUAL-W2 41
3.3.1 Model background 41
3.3.2 Theory of CE-QUAL-W2 model hydraulic function 44
3.3.3 Theory of CE-QUAL-W2 model water quality function 52
3.3.4 Hydraulic data, Water quality data and input files preparation 68
3.3.5 Reservoir division of the grid 71
3.4 Introduction of Data processing for the reservoir model based on Global Climate Models (GCMs) criteria 74
3.4.1 Data processing for the reservoir model 74
3.4.2 The introduction of pattern scaling method. 90
Chapter 4 RESULT AND DISCUSSION 92
4.1 W2 model hydraulic calibration (2004-2008) and validation (2009-2012) 92
4.1.1 Water surface elevation calibration and validation 92
4.1.2 Water surface temperature calibration and validation 98
4.2 W2 model water quality calibration and validation 113
4.2.1 Dissolved oxygen 117
4.2.2 Nutrients 120
4.2.3 Chlorophyll a and Suspended solid 129
4.3 Water temperature and water quality simulations under climate change scenarios 134
4.3.1 Water temperature 136
4.3.2 Dissolved oxygen 146
4.3.3 Nutrients 155
4.3.4 Chlorophyll a 177
Chapter 5 CONCLUSION AND SUGGESTION 181
5.1 Conclusion 181
5.2 Suggestion 183
REFERENCE 185
APPENDIX 195

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