Ch 2 Water Problems 授課老師:王根樹

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1 Ch 2 Water Problems 授課老師:王根樹
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2 經濟部水利署 （資料來源：經濟部水利署）

3 Water cross-cutting all areas
Energy Health Water Agriculture Biodiversity

4 目前面對的嚴重環境議題 氣候變遷 平流層的臭氧消耗 生物多樣性消失 酸化（酸雨及土壤） 光化學氧化劑 淡水資源管理 森林濫墾濫伐
沿海地區的威脅及管理 廢棄物及處理 都市化之壓力 化學物質風險 Climate change: greenhouse gas emissions are projected to increase in the EU by about 6% from 1990 to Atmospheric concentrations of CO2 , CH4 and NOx could rise by as much as 45%, 80% & 20% respectively to A doubling of global carbon dioxide is expected, producing an estimated temperature rise of 1.5 to 4.5oC. Stratospheric ozone depletion: concentrations have declined at mid-latitudes over Europe by 6 to 7 per cent during the past decade. However, the ozone layer is benefiting from the phasing out of ozone depleting substances, but it will only start to recover after the mid 2030s and is not expected to recover fully before Consequently, ultra-violet radiation levels and associated damaging affects, e.g.. skin cancer are expected to increase. The loss of biodiversity: between a third and a half of all fish, reptiles, mammals and amphibians in Europe are under threat. Major accidents: the specific problems of nuclear safety in Central and Eastern Europe are being tackled by a strategy of assistance by 24 countries. Over 300 major industrial accidents have been reported in the EU since 1984. Acidification: severe acidification of freshwater affects southern Scandinavia. However, emissions from all major gases contributing to acidification and eutrophication are expected to be reduced - leading to significant improvements to ecosystems threatened by these phenomena. Ground-level ozone and other photochemical oxidants: short-term summer peak levels of ground-level ozone affect more than 100 million Europeans. The management of freshwater: widespread over-application of fertilisers in agriculture is affecting the quality of surface waters and groundwater. However, the quality of rivers and lakes should improve, due to decreased input of nitrogen and phosphorus (ref. Urban Waste Water Treatment Directive). Forest degradation: a 1992 survey in 24 countries showed that 24 per cent of trees were damaged by defoliation. Coastal zone threats and management: marine pollution of the coastal zone is a serious problem in all of Europe’s seas. Waste production and management: an increasing amount of industrial waste is considered hazardous. Urban stress: urban traffic is an increasingly important source of air pollution; urban transport account for about 30 per cent of total energy use in most cities. Chemical risks: about 100,000 chemicals are marketed in the EU, and between 200 and 300 new ones appear each year. For 75% of the large volume chemicals on the market, there is insufficient analysis of toxicity and eco-toxicity available to support minimal risk assessment. 4

5 水的全球觀點 水文循環的主要過程: 貯存: 海洋: 97% 冰冠和冰河: 2% 大氣: 0.001% 總量：相當豐富，並無水量不足的問題
由地面與海洋回到大氣 再從大氣降下至地面與海洋 貯存: 海洋: 97% 冰冠和冰河: 2% 大氣: 0.001% 總量：相當豐富，並無水量不足的問題 水資源的主要問題： 在對的時間、地點供應良好水質的可行性 能有效供應動植物需求（包含人類在內）的水量不到總量的1%

6 Introduction 全球淡水資源供應日趨不足 可用水量及水質均降低 主因在於人為污染日趨嚴重 1.4 billion km3

7 水體主要汙染壓力來源 農業 - 此為主要的汙染來源，其排放的水量 遠大於工業及民生廢棄物。例如：美國70%的 水汙染都是由此造成 。
衛生下水道不足 - 在開發中國家, 有90 – 95% 的家庭汙水未經過處理即排入地面水中 工業 - 在開發中國家，有75% 的工業廢水也 未經過適當的處理就排出 → 台灣地區污水下水道建設？

8 兩大主要壓力 水的汲取率往往高於補注率（何謂「補注」？）, 因此造成可用蓄水量的逐漸下降
淡水的污染是水質安全及使用的一大問題，且需要極大的財力投入來解決 → 污水下水道及處理設施 – 看不到的建設 Considerable water pollution is caused by: Uncontrolled discharges into natural resources; Eutrophication caused by fertiliser run-off from agricultural land, and Acidification of lakes by acidic deposition and leaching through contaminated soils and landfills. Water quality monitoring is now an important prerequisite to ensure that a reliable source of water can be maintained. Water management in many countries is poorly planned resulting in: Over exploitation of groundwater; Increasing encroachment of saline water into aquifers along coastal zones; Excessive localised irrigation causing water logging, salinisation and accelerated land degradation; Lack of maintenance and capital investment in the water supply infrastructure; Water losses of greater than 70% of water delivered, causing an increasing demand for pure water; and Poor control over water quality with the associated health, ecological and aesthetic problems. The traditional approach to water supply management has been to construct dams in strategically important catchment areas. Dams provide the capability to control floods and store water to meet demand as it arises. Although dams have significant benefits they are associated with major environmental implications. Dams can: Alter land use patterns; Affect natural habitats; and Change the route of natural water courses. Dams represent significant capital investment and the projects are often heavily subsidised by international agencies such as the World Bank. The United Nations has been particularly instrumental in developing water quality and supply improvements. The UN Conference on Human Settlements held in Vancouver, Canada, in 1976 launched the International Drinking Water Supply and Sanitation Decade from In 1970, 33% of the population in urban areas of developing countries did not have access to safe clean water. By 1990, only 18% in this category did not have access to clean water. 8

9 過度使用淡水水資源 從湖泊或河川抽取過多的淡水使用，導致地表水資源日趨匱乏。 美國西南部已有70%的地表水被抽取使用。 地表水資源不足使得濕地乾沽，鳥類的棲息地銳減，臨海地區水體鹽化。 Owens Lake -在1913年將Owens River的合水導引到距離223哩的洛杉磯，導致Owens Lake在1926年乾涸 Wiki Mav at en.wikipedia

10 主要水污染物之類別 The biggest impact most industrial and domestic discharges have on the receiving water is through their oxygen demands and most pollution control technology in use is designed to minimise oxygen demands of effluent discharges. Dissolved Oxygen (DO) The saturation concentration of DO at normal temperature is about 10 mg 1-1. The minimum DO required for maintaining a balanced population of acquatic life is about 5 mg1 -1. Even a small oxygen demand can have a significant effect on a river. BOD (Biological Oxygen Demand): The amount of oxygen actually used in biological degradation COD (Chemical Oxygen Demand) The amount of oxygen consumed in the complete oxidation of carbonaceous matter in an effluent sample.

11 世界各國下水道普及率(2000年) 領先集團 荷蘭 瑞典 瑞士 德國 盧森堡 97.4 94 93 88.6 88 東南亞國家 新加坡 南韓
單位: % 領先集團 荷蘭 瑞典 瑞士 德國 盧森堡 97.4 94 93 88.6 88 東南亞國家 馬來西亞 新加坡 南韓 菲律賓 印尼 85.2 82 52.6 42 40 台灣: < 20% 資料來源： 全球國家競爭力評比

12 缺水影響半個地球 在開發中國家，有將近20億的人口缺少安全的水供應及良好衛生環境 半數的開發中國家，只能供應少於65%的民眾安全的飲用水
超過兩億的人口受到長期缺水的影響 There are only 20 countries world wide that can be said to have a systemic “water shortage”--a water resource around or below the 1,000 cubic meters/year per capita renewable flow that is commonly taken as the threshold for adequate water supply1. Yet half the developing countries provide safe water to less than two-thirds of their populations--with a marked bias favoring connections in the larger urban areas, and, of course, irrigation water supply. Around two billion people have no permanent safe water connections and 200,000 more are subject to periodic or seasonal supply interruptions. Water resource endowments are least in north Africa and the Middle East (13 of the 20 dry countries are in that region) but the service record is somewhat better in those countries than in regions with more abundant endowments: the mean connection rate for safe water in Mena is 74% and the median 85%, compared with 58% (for both mean and median) in Asia (which enjoys about three and one-half times Mena’s annual water availability)2 and an overall average for the developing countries of 63% connected. Not surprisingly, Mena countries also consume a far larger proportion of their water resources than countries in other regions. Water withdrawals (or consumptive uses of water) represent nearly half the annual resource endowment in Mena, compared with less than 20 percent in Latin America, 8 percent in Asia, and overall 10 percent on average for all emerging economies. Despite strong international programs, progress in improving the availability of safe drinking water has been slow. Over about the past ten years, the median connection rate has risen by only about 8 points 3, representing new connections for only about 650 million people, only about 40 percent of the 1.7 billion population growth in the low and middle income countries in that period. 1. World Bank, Water Resources Management Policy Paper (1993), updated to 1995 data from World Development Indicators, Countries are: Algeria (529),Burundi (575), Egypt (1005), Israel (398), Jordan (332), Kenya (1132), Korea (1474), Kuwait (0), Lebanon (1199), Libya (111), Morocco (1129), Oman (911), Rwanda (984), Saudi Arabia ( 116), Singapore (201), South Africa (1206), Tunisia (434), UAE (122), UK (1213), Yemen (164). cubic meters/ year/capita in Asia vs 1386 in Mena) 3. At the aggregate level the mean and the median are similar, indicating little skewness in the distribution. 12

13 供給端的問題 過速的都市發展造成表土及植披覆蓋 流失。 供水系統缺乏有效管理 進展緩慢的私營化過程 氣候異常事件
（why privatization?） 氣候異常事件 I think that the growing problem of poor access to water and quality of service can be laid on poor supply responses. I want to spend few minutes sketching out the principal supply-side failures that have contributed to the wholly unsatisfactory performance of public utilities in meeting water supply needs in the developing countries. I hope to show in the remaining time that I have, that treating water as an economic good--pricing it, creating clear property rights for water, and allowing water trading--will go a long way towards overcoming each of these barriers. And, not incidentally, towards also assuring that the boom in water investment that would follow such a change in approach could be financed. 13

14 可再生的水資源供應 由於表面的徑流以及滲入地下蓄水層的淡 水供應，因此水資源是可再生的資源
取水 = 為任何用途所汲取的總水量。每年 人類汲取的水量約為可再生水資源的10% 消耗= 水因為蒸發、蒸散、被植物或作物 吸收 、被人類或家畜所消耗、或是直接注 入海洋而使得這些水資源無法再被利用

15 可更新的供應量 水的消耗量不包含在各使用點間的使用量及運輸 過程間的損耗 。大約有30 – 50%的都市水由於有 漏洞的管線所損失。在挪威，因此而損失的比率 高達70% 台北市漏水率~37.3％ 台灣省~23％ 水質惡化（Degradation） → 水質的改變使得水不再那麼易於使用

16 台灣為什麼會缺水？ 地狹人稠、山坡陡峻，以及颱風豪雨雨勢急促，大部分的降雨皆迅速流入海洋。
台灣地區降雨量為世界陸地平均降雨量的3倍以上，但平均每人每年所分配的水資源只有世界平均值的七分之一。

17 台灣地區水資源運用狀況(民國86～90年平均值)
地下水超抽 7.2億噸 生活用水 33億噸(18%) 工業用水 17億噸(9%) 農業用水 126億噸(68%) 水庫供水量 44億噸(24%) 河川引水量 83.6億噸(45%) 地下水抽用量 58億噸(31%) 總用水量 185.6億噸 地下入滲量 50.8億噸 河道逕流量 661億噸 降雨量 936億噸 蒸發損失量 224億噸 100% 24% 71% 入海 533.4億噸 5% 保育用水 9.6億噸(5%) 經濟部水利署

18 全球性地表水議題 在二十世紀期間，死海的水平面下降了超過十公 尺
以色列和約旦在1981年簽訂協議增加由約旦河取 水的體積, 約旦河的水量已減少到只比一條排水 溝再多一點 位於以色列北邊負責供應其南邊水資源的Galilee sea, 近來其水體已逐漸縮減並且鹽化 類似此種水資源匱乏的現象已是全球性的問題

19 地下水的問題 地下水體積約占可使用淡水總量的95%，但卻不 容易被汲取 以美國為例：
約有50%的美國人從地下水中獲得他們全部或大部分的 飲用水 約有95%的鄉村住民仰賴地下水為其飲用水來源 大約有一半的農田其灌溉水源是地下水 約有三分之一的工業用水需由地下水供應 台灣西南沿海因地下水超抽所衍生地層下陷的問 題已日趨嚴重

20 地下水超限利用 地層下陷的圖、海水鹽化 台灣大學 王根樹

21 水需求減少的原因.... 經濟活動的減少 用水量的有效控制及管理 水價的調整

22 南亞地區水資源使用趨勢 迅速的都市化 – 都市用水量增加 工業用水需求 環境保護及保育用水 水質問題

23 農業污染問題 土壤腐蝕︰ 土壤自原來位置的任何運動 沈積︰ 離土壤原先的位置的移動，移至非原先位置的環境。

24 腐蝕問題 腐蝕問題與土壤起源的場所有關。 土壤生產力的喪失 因水沖刷所產生的乾涸溝渠限制了農民在農地工作的方便性 降低保水能力
降低土壤肥沃性 降低土壤適耕性 因水沖刷所產生的乾涸溝渠限制了農民在農地工作的方便性

25 台灣大學 王根樹 台灣大學 王根樹 艾莉颱風後的平鎮淨水廠 台灣大學 王根樹

26 沈積問題 只有最小和最輕土壤顆容易移動。 沈積損失通常少於20%的總土壤腐蝕損失；一般常低於5%。 在溪水和湖裡引起混濁。
不那麼健康的水產棲息地

27 優養化（Eutrophication） 地面水含有過高植物營養源 通常導致過度的植物和藻類生展，並引起季節性的缺氧 氮和磷均有所貢獻
在淡水裡磷通常是限制因子。

28 Myponga, SA 台灣大學 王根樹 台灣大學 王根樹 27 台灣大學 王根樹

29 台灣大學 王根樹 台灣大學 王根樹

30 有機物 揮發性有機物 合成有機物、農藥 芳香族碳氫化合物 含氯碳氫化合物 苯、甲苯、乙苯、二甲苯等，均為汽油成份
受石油污染之水源(旗山溪事件) 含氯碳氫化合物 三氯乙烯、四氯乙烯、二氯乙烷、三氯乙烷等 常為工業廢棄物或廢水不當排放，造成地下水水源污染(大寮鄉昭明村地下水井三氯乙烯事件) 合成有機物、農藥 特別注意環境荷爾蒙、個人照護用品的問題

31 Wiki Mav at en.wikipedia
作品 授權條件 作者/來源 經濟部水利署 2011/09/13 visited Wiki USGS /09/13 visited Wiki Mav at en.wikipedia /NCSD/img/img/14889/4-3.ppt 台灣大學 王根樹 7.2億噸 地下水超抽 33億噸(18%) 生活用水 17億噸(9%) 工業用水 126億噸(68%) 農業用水 44億噸(24%) 水庫供水量 83.6億噸(45%) 河川引水量 58億噸(31%) 地下水抽用量 185.6億噸 總用水量 地下入滲量 50.8億噸 河道逕流量 661億噸 936億噸 降雨量 蒸發損失量 224億噸 100% 24% 71% 533.4億噸 入海 5% 9.6億噸(5%) 保育用水

32 作品 授權條件 作者/來源 台灣大學 王根樹 2011/09/13 visited