水资源 -- -- 高级

What are resources?
::什么是资源?

Water resources can be defined as sources of water that are useful or potentially useful. Uses of water include agricultural, industrial, household, recreational and environmental activities.
::水资源可界定为有用或潜在有用的水源,用水包括农业、工业、家庭、娱乐和环境活动。

Water Resources
::水资源 水资源

At the intersection of land and water resources are wetlands : swamps, marshes and bogs whose soil is saturated ( Figure  ). Historically, humans have viewed wetlands as wasted land; the U.S. has lost as much of 50% of its wetlands to , , and flood control. Recently, wetland loss and the loss wetland has taught us the importance of this . Ecosystem services provided by wetlands include:
::土地和水资源交汇处是湿地:沼泽地、沼泽地和土壤饱和的沼泽地(图 ) 。 历史上,人类将湿地视为荒废的土地;美国丧失了50%的湿地到控制洪水。 最近,湿地的丧失和湿地的丧失让我们认识到了这一湿地的重要性。 湿地提供的生态系统服务包括:

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1. water storage and replenishment of aquifers
   ::含水层的蓄水储存和补充
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2. protection of coastlands from tides and storms
   ::保护海岸地带免受潮汐和暴风雨的侵扰
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3. flood control
   ::防洪防洪
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4. water purification I: slowing of water flow allows sedimentation to remove particulates
   ::水净化一:水流减慢使沉积得以去除微粒
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5. water purification II: denitrification of excess nutrients
   ::水净化二:过量营养物质脱硝
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6. rich habitat for wildlife
   ::野生动物富丰富的栖息地
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7. rich habitat for plants (30% of U.S. plant diversity)
   ::植物丰富生境(占美国植物多样性的30%)
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8. recreation: hunting, fishing, ecotourism (e.g., The Everglades)
   ::娱乐:狩猎、捕鱼、生态旅游(例如,长河)

In the U.S., at least, recognition of the economic value and of wetlands has led to restoration efforts and requirements for replacement of those lost through development. The Ramsar “Convention on Wetlands of International Importance, especially as Waterfowl Habitat,” signed by 18 nations in 1971, works to conserve wetlands throughout the world for their ecological services and their economic, scientific, cultural, and recreational values. Signatories today number 157, and they meet every 3 years.
::至少在美国,对经济价值和湿地的承认导致恢复努力和要求,以取代那些因发展而损失的人。 1971年18个国家签署的拉姆萨尔《关于具有国际重要性的湿地,特别是作为水禽栖息地的湿地的公约》致力于保护世界各地的湿地,使其享有生态服务以及经济、科学、文化和娱乐价值。 今天,签署者人数为157人,他们每三年开会一次。

Water is the quintessential resource of life; its unique physical, chemical and biological properties make it difficult for us to imagine life on any planet which lacks liquid water. For human use, however, water must be fresh. About 97% of Earth’s water is found in the oceans. Of the 3% which is fresh water, over 2/3 is locked in ice. The 1% which is fresh liquid water is mostly below ground, leaving just 0.3% as surface water in lakes and rivers ( Figure  ). The atmosphere contains just .001%.
::水是生命的典型资源;它独特的物理、化学和生物特性使我们难以想象任何缺乏液态水的星球上的生命。然而,对于人类来说,水必须是新鲜的。大约97%的地球水是在海洋中发现的。在3 % 的淡水中,有2/3以上被锁在冰中。1 % 的液态水大部分在地下,只有0.3%作为湖泊和河流中的地表水(图 ) 。大气中只有0.001%。

As industry, agriculture, development, and a growing world use more water, fresh water supplies are shrinking due to over-drafting of groundwater and pollution of surface and groundwater. Over-drafting has lowered water tables in Texas, California, and India, leaving many wells dry. New Orleans is below sea level, and San Jose, California dropped 13 feet, because over-pumping caused the land to subside. The UN and others have labeled the current state of water resources throughout the world a Water Crisis. You might wonder why we don’t tap the oceans; the answer is that desalination is extremely costly in terms of energy and economics. The UN estimates that 1.1 billion people worldwide are without adequate fresh water, and that 2.6 billion lack enough water for sanitation to protect from disease. Water conflicts in the Middle East, Eastern Europe, and Korea have threatened regional political stability.
::作为工业、农业、发展和日益扩大的世界用水量增加的原因,淡水供应由于地下水透支以及地表和地下水污染而正在萎缩。 透支降低了得克萨斯州、加利福尼亚州和印度的地下水位,使许多水井干涸。 新奥尔良低于海平面,而加利福尼亚州圣何塞则下降了13英尺,因为过度抽水造成土地倾斜。 联合国和其他人把全世界水资源的现状贴上了水危机的标签。 你可能会怀疑为什么我们不开发海洋;答案是海水淡化在能源和经济方面代价极高。 据联合国估计,全世界有11亿人没有充足的淡水,26亿人缺乏足够的卫生用水来防止疾病。 中东、东欧和韩国的水冲突威胁着区域政治稳定。

, especially from non point sources ( non point source pollution ) or runoff , threatens vital freshwater and resources in the U.S. and throughout the world. A single example dramatically illustrates the potential for disruption of natural cycles and loss of biodiversity. Runoff of fertilizers applied to vast expanses of agricultural land and other sources such as wastewater have led to what ecologists say is a doubling of the amount of nitrogen available to plants and , and that amount could increase by another 60% by 2050. At first glance this may seem like a benefit to life, but it is not. Especially in ecosystems, excessive nutrients lead to overgrowth of , creating algal blooms . Some species are toxic in themselves, but more often, this eutrophication - literally, “feeding too well” - leads to such high levels of respiration (recall that photosynthesizers must respirate – especially at night!) that dissolved oxygen levels plummet, resulting in the death of and other species. Death results in decomposition and further nutrient input – compounding the problem. Eutrophication threatens one of the most diverse habitats on earth – coral reefs, which cover just 1% of the earth’s surface yet harbor 25% (over 4000) - of marine fish species. Adapted to low-nutrient environments and characterized by tight nutrient cycles, reefs in the pathway of excess nutrient runoff from agriculture and development become overgrown with algae, which block light from coral polyps . The Nature Conservancy predicts that 70% of Earth’s coral reefs will have disappeared by 2050 if current rates of destruction continue.
::特别是来自非点源(非点源污染 ) 或径流, 威胁着美国和全世界至关重要的淡水和资源。 仅举一个例子就明显地说明了自然循环和生物多样性丧失的破坏潜力。 肥料的流失导致大量农业用地和废水等其他来源的肥料的流失,导致生态学家说,植物可获得的氮量翻了一番,到2050年,这一数量可能会再增加60 % 。 乍看起来这似乎对生命有益,但事实并非如此。 特别是在生态系统中,过度的营养导致海藻的过度增长,从而造成藻类的繁茂盛。 某些物种本身有毒,但更经常地是,这种富营养化 — — 事实上, " 摄取性太好 " 的肥料导致如此高的再生水平(人们注意到光合剂必须重新燃起植物的氮含量,特别是在夜间! ) 溶解氧水平会下降,导致其他物种死亡。 死亡的结果是腐蚀性,但更多的营养素流入 — — 使得问题更为复杂。 营养化的结果是,由于碳质的不断变质的不断变质的海路流 — — — 珊瑚礁会持续成为地球上的40种 — — — 不断的珊瑚礁 — 不断的腐蚀化循环覆盖着海洋的海洋的海洋的海洋的退化的退化的退化的退化环境。

Among the most devastating consequences of eutrophication are at least 146 dead zones , where low oxygen levels caused by eutrophication have extinguished all ocean life. The most notorious extends into the Gulf of Mexico at the mouth of the Mississippi River, which brings fertilizer runoff from the U.S. corn belt ( Figure  ). In July of 2007, this dead zone covered an area of ocean the size of New Jersey and affected shrimp and fishing industries as well as countless species of marine organisms . Interestingly, a similar zone in the Black Sea disappeared between 1991 and 2001, after political changes in the Soviet Union and Eastern Europe made fertilizers too expensive to use for most agriculture. Unfortunately, most are growing, and the disruption affects many bodies of freshwater throughout the world, as well.
::富营养化最具有破坏性的后果至少有146个死区,富营养化造成的低氧水平已使所有海洋生命消亡。最臭名昭著的地区延伸到密西西比河口的墨西哥湾,这导致美国玉米带(Figure ) 的肥料流失。 2007年7月,这个死区覆盖了新泽西的海洋面积和受影响的虾和捕鱼业以及无数海洋生物物种。 有趣的是,1991年至2001年,在苏联和东欧的政治变革使肥料太昂贵,无法用于大多数农业之后,黑海的类似地区也消失了。 不幸的是,大部分的肥料正在增长,破坏也影响到世界各地许多淡水。

Summary
::摘要

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• Wetlands, greatly reduced because of earlier views that they were wasted land, provide many ecosystem services, including flood control, water purification, aquifer recharge, plant and wildlife habitat, and recreation.
  ::湿地因早先认为它们是荒地而大幅减少,提供许多生态系统服务,包括防洪、净水、含水层补给、植物和野生生物生境以及娱乐。
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• Liquid fresh water, the primary water resource for human use, comprises less than 1% of all water on Earth; most of this is groundwater.
  ::液态淡水是人类使用的主要水资源,占地球所有水的不到1%;其中多数是地下水。
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• As industry, agriculture, development, and a growing world population use more water, fresh water supplies are shrinking due to over-drafting of groundwater and pollution of surface and groundwater.
  ::由于工业、农业、发展以及世界人口不断增加,由于地下水的透支以及地表水和地下水的污染,淡水供应日益减少。
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• According to the United Nations, the current Water Crisis involves 1.1 billion people without adequate water supplies and 2.6 billion people who lack adequate water for sanitation.
  ::据联合国称,目前的水危机涉及11亿人没有适当的供水,26亿人没有适当的卫生设施。
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• Agricultural fertilizer runoff and waste water add excess nutrients to surface waters, leading to algal blooms and eutrophication.
  ::农业肥料径流和废水增加了地表水的过剩营养,导致藻类开花和富营养化。
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• Dead zones in coastal areas such as the Gulf of Mexico result from agricultural runoff from large areas of land. The dead zone at the mouth of the Mississippi River was the size of New Jersey in the summer of 2007.
  ::2007年夏季,密西西比河口的死区相当于新泽西岛的面积。

Review
::回顾

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1. List the ecosystem services of wetlands, and describe the extent of their loss in the United States.
   ::列出湿地的生态系统服务清单,并说明在美国湿地的损失程度。
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2. Earth is the “water planet.” Why are we threatened with a Water Crisis?
   ::地球是“水星球 ” 。 为什么我们面临水危机的威胁?
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3. Explain why eutrophication – “too much a good thing” results in problems for aquatic life.
   ::解释为什么富营养化 — — “太好的事情”会导致水生生物的问题。
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4. Analyze the disappearance of the Black Sea “dead zone” for its potential to help solve water pollution problems.
   ::分析黑海“死区”的消失情况,因为它有可能帮助解决水污染问题。

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::探索更多