人类与供水

Lesson Objectives
::经验教训目标

• List ways that humans use water.
  ::列出人类使用水的方式。

• State why some people don&'t have enough water.
  ::说明为什么有些人没有足够的水。

• Explain why poor quality water is a problem.
  ::解释为什么水质差是一个问题。

Lesson Vocabulary
::词汇表课程

• drought
  ::干旱干旱和干旱干旱

• irrigation
  ::灌溉灌溉

Introduction
::导言

All forms of life need water to survive. Humans can survive for only a few days without it. That's not very long. It is far less time than humans can go without food. Besides drinking, people also need water for other purposes. For example, water is used for cleansing, agriculture, industry, and many other uses. Clearly, water is one of Earth's most important natural resources. It's a good thing that water is recycled in the water cycle.
::所有生命形式都需要水才能生存。 没有水,人类只能生存几天。 时间不长。 比人类没有食物的时间要短得多。 除了饮用水, 人们还需要水, 还有其他目的。 例如, 水用于清洁、 农业、 工业和其他许多用途。 显然, 水是地球上最重要的自然资源之一。 水在水循环中回收是一件好事。

How We Use Water
::我们如何用水

Figure    shows how people use water worldwide. The greatest use is for agriculture and then industry. Municipal use is last, but is also important. Municipal use refers to water used by homes and small businesses.
::图表显示了全世界人们如何用水,最大的用水是农业,其次是工业,城市用水是最后的,但也很重要,城市用水是指家庭和小企业用水。

Water in Agriculture
::农业用水

You know that plants need water. It would seem obvious that a desert would not be a great place to grow crops. That is not the case. Many crops are grown where there is limited water. For example, crops are grown in deserts of the American southwest. How is this possible? The answer is irrigation.  Irrigation  is any way of providing extra water to plants. Most of the water used in agriculture is used for irrigation. Livestock also use water, but they use much less.
::你知道植物需要水。显然沙漠不是种植作物的好地方。情况并非如此。许多作物是在水量有限的地方种植的。例如,农作物是在美国西南部的沙漠里种植的。这怎么可能?答案是灌溉。灌溉是给植物提供额外水的任何方法。农业用水大多用于灌溉。牲畜也使用水,但用水少得多。

Irrigation can waste a lot of water. The type of irrigation shown in  Figure    is the most wasteful. The water is sprayed into the air and then falls to the ground. But much of the water never reaches the crops. Do you know why? Of course, some of it evaporates into the air. It never reaches the ground. Even when the water does reach the ground, it may just run off, never reaching the plants. Irrigation water may cause other problems. The water may dissolve chemicals. These chemicals include pesticides and fertilizers. When the water soaks into the ground so do the chemicals. They may enter groundwater. They may run off into nearby rivers or lakes. 
::灌溉会浪费大量的水。 图中显示的灌溉类型是最浪费的。 水被喷入空气中, 然后倒在地上。 但大部分水从未到达庄稼。 您知道为什么吗 ? 当然, 有些水蒸发到空气中, 有些水从未到达地面。 即使水到达地面, 也可能直接流出, 无法到达植物。 灌溉水可能会引起其他问题。 水可能会溶解化学物质。 这些化学物质包括杀虫剂和肥料。 当水渗入地面时, 这些化学物质也会渗入土壤。 它们可能会进入地下水, 它们可能会跑到附近的河流或湖泊。

Industry Uses of Water
::水的工业利用

Almost a quarter of the available water is used in industry. Industries use water for many purposes. Chemical processes need a lot of water. Water is used to generate electricity. Sometimes water is used to cool machines and power plants.
::工业为多种目的使用水,化学过程需要大量水,水用于发电,有时水用于冷却机器和发电厂。

Household Uses of Water
::家庭用水情况

Think about all the ways people use water at home. Certainly you drink water, but there are many other ways you use it. You may use it to cook. Think about the pot of boiling water needed to cook spaghetti. You also use water to clean up the mess after eating your spaghetti. You may take a shower or bath at night, or in the morning before school. Can you think of some other uses of water in your home?  
::想一想人们在家里用水的方式。当然,你们可以饮水,但你们可以用水做饭,你们可以用水做饭。你们可以吃意大利面,也可以用水来清理家里的垃圾。你们可以在晚上或上学前的早晨洗个澡,或者洗个澡。你们能想到家里的水吗?

Most of the water used in your home goes down the drain. From there it usually ends up in a sewer system. It ends up at the sewage treatment plant. That's not the end of the road for water. The treatment plant prepares the water for reuse.
::家庭用水大部分从下水道中流出, 通常最终会进入下水道系统, 最终会进入污水处理厂。 这不是水路的尽头。 处理厂准备水再利用 。

Households may also use water outdoors. Maybe you water your lawn or garden? You may use water to wash the family car. Much of the water used outdoors evaporates or runs off into the gutter. The runoff water may end up in storm sewers. From there it may move into a nearby body of water. Maybe it is a local lake. It might eventually make it to the ocean.
::家庭也可以户外用水。也许您可以给草坪或花园浇水?您可以用水洗家用车。大部分户外用水蒸发或冲进水沟。径流水可能流入下水道,从那里流到附近的水中。也许这是一个地方性湖,最终可能到达海洋。

Water for Fun
::欢乐之水

There are many ways to use water for fun. Maybe you want to try white water rafting or snorkeling someday. It sure looks like fun! When you do these activities, you don't actually use water. You are doing the activity on or in the water. What do you think is the single biggest use of water for fun? Believe it or not, it's golf! Keeping golf courses green uses large amounts of water. Golf courses use irrigation to keep them looking green. Many golf courses, have large sprinkler systems. Much of this water is wasted. It evaporates or runs off the ground.
::有许多方法可以使用水来取乐。 也许有一天你想尝试白水漂浮或潜水。 看起来确实很有趣。 当你做这些活动时, 你并不实际使用水。 您正在水中或水中做活动。 您认为水的最大用途是什么? 信不信由你, 这是高尔夫球! 保持高尔夫球场绿色使用大量水。 高尔夫球队使用灌溉来保持它们看起来绿色。 许多高尔夫球队, 拥有大量的喷洒系统。 这些水大部分是浪费的。 它蒸发或流离地面。

Water Problems: Not Enough Water
::水问题:水不足

Most Americans have plenty of fresh, clean water. But many people around the world do not. In fact, water scarcity is the world's most serious resource problem. How can that be? Water is almost everywhere. More than 70 percent of Earth's surface is covered by water.
::大多数美国人拥有充足的淡水清洁水,但全世界许多人却没有。事实上,缺水是世界最严重的资源问题。这怎么可能?水几乎无处不在。地球表面有70%以上的水覆盖着地球。

Where Is All The Water?
::所有的水都到哪里去了?

One problem is that only a tiny fraction of Earth's water is fresh, liquid water. Many plants and animals need fresh liquid water to survive. More than 97 percent of Earth's water is salt water in the oceans. Salt water will kill most land plants and animals. Only 3 percent of Earth's water is freshwater. Most of the freshwater is frozen in ice sheets, icebergs, and glaciers (see  Figure   ). That does not leave us with much water. That's why it is important to conserve and protect our freshwater. 
::其中一个问题是,地球水中只有一小部分是淡水和液态水,许多动植物需要淡水和液态水才能生存。超过97%的地球水是海洋中的盐水。盐水将杀死大多数陆地植物和动物。只有3%的地球水是淡水。大部分淡水被冰盖、冰山和冰川冻结(见图 ) 。这不会给我们留下太多的水。这就是为什么保存和保护我们的淡水是重要的。

Rainfall and Water Supply
::降雨和供水

Rainfall varies around the globe. About 40 percent of the land gets very little rain. As a result, many people do not have enough water. Drier climates generally have less water for people to use. Imagine this, what you may use in one day is what other people may get in a year. 
::降雨量在全球各地各不相同。 大约40%的土地降雨量很少。 结果,许多人没有足够的水。 德瑞尔气候通常较少供人们使用。 想象一下,在一天里,你可能用到的就是其他人在一年中可能得到的。

Wealth and Water Supply
::财富和水供应及 财富和水供应

Richer nations can drill deep wells. They can build large dams. They can extract freshwater from ocean water. In these countries, just about everyone has access to clean running water in their homes. It's no surprise that people in these countries also use the most water. In poorer nations, there is little money to develop water supplies. Look at the people in  Figure   . These people must carry water home in a bucket from a distant pump.
::富国可以钻深水井。它们可以建造大型水坝。它们可以从海水中提取淡水。在这些国家,几乎每个人都可以在家中获得清洁的自来水。毫不奇怪,这些国家的人也用水最多。在较贫穷的国家,发展供水的资金很少。看看图中的人。这些人必须用远处的水泵把水桶装在桶里运回家。

Water Shortages
::缺水

Water shortages are common in much of the world. People are most likely to run short of water during droughts. A  drought  is a period of unusually low rainfall. Human actions have increased how often droughts occur. In some areas, humans have cut down all the trees. This action can bring on a drought. Trees add a lot of water vapor to the air. With fewer trees, the air is drier and droughts are more common.
::世界上大部分地区普遍缺水,干旱期间人们最可能缺水。干旱是降雨量异常低的时期。干旱是降雨量异常低的时期。人类的行动增加了干旱发生频率。在某些地区,人类已经砍伐了所有的树木。这可能造成干旱。树木会增加大量的水蒸气。树木减少,空气干燥,干旱更常见。

We use six times as much water today as we did a hundred years ago. As the number of people rises, our need for water will grow. By the year 2025, only half the world's people will have enough clean water. Water is a vital resource. Water shortages may even lead to other problems.
::我们今天用水量是一百年前的六倍。 随着人口数量的增加,我们对水的需求将增加。 到2025年,只有一半的世界人口将拥有足够的清洁水。水是一种至关重要的资源。水的短缺甚至可能导致其他问题。

• Crops and livestock may die. As a result, people will have less food available.
  ::作物和牲畜可能死亡,因此,人们获得的食物将减少。

• Other uses of water, such as industry, may have to stop. This reduces the number of jobs available to people of that area. 
  ::其他用水,如工业,可能不得不停止,这减少了该地区人民可得到的工作数量。

• People and nations may fight over water resources.
  ::人民和国家可能争夺水资源。

• In extreme cases, people may die from lack of water.
  ::在极端情况下,人们可能因缺水而死亡。

Figure    shows the global water situation in the 2030s with water stress and water scarcity on the map.
::图中显示了2030年代全球水资源状况,地图上有缺水和缺水。

Water Problems: Poor Quality Water
::水问题:水质差

The water Americans get from their faucets is generally safe. This water has been treated and purified. But at least 20 percent of the world's people do not have clean drinking water. Their only choice may be to drink water straight from a river (see  Figure   ). Some rivers are polluted. It may contain bacteria and other organisms that cause disease. Almost 9 out of 10 cases of disease worldwide are caused by unsafe drinking water. The drinking of unsafe water is the leading cause of death in young children.
::美国人从水龙头得到的水一般是安全的,这种水经过了处理和净化,但世界上至少有20%的人没有清洁的饮用水,他们唯一的选择是直接从河流里喝水(见图)。一些河流被污染,其中可能含有细菌和其他疾病生物。全世界10个疾病病例中,有9个病例是由不安全的饮用水造成的。不安全水的饮用是幼儿死亡的主要原因。

Lesson Summary
::经验教训摘要

• People use water for agriculture, industry, and municipal uses. Irrigation for agriculture uses the most water.
  ::人们将水用于农业、工业和市政用途,农业灌溉用水最多。

• Too little water is a major problem. Places with the least water get little rainfall. They also lack money to develop other water resources. Droughts make the problem even worse.
  ::水太少是一个大问题。 水源最少的地方降雨量很少,也缺乏开发其他水资源的资金。 干旱使问题更加严重。

• Poor water quality is also a problem. Many people must drink water that contains wastes. This causes a lot of illness and death.
  ::水质差也是一个问题,许多人必须饮用含有废物的水,这造成许多疾病和死亡。

Lesson Review Questions
::经验回顾问题

Recall
::回顾

1. List the three major ways that humans use water.
   ::列出人类用水的三个主要方式。

1. What is the single biggest use of water in agriculture?
   ::农业用水的单一最大用途是什么?

1. Give an example of an industrial use of water.
   ::举一个工业用水的例子。

1. Why does golf use a lot of water?
   ::为什么高尔夫会用很多水?

1. What problems may result from serious water shortages?
   ::严重缺水可能造成什么问题?

Apply Concepts
::应用概念

6. Briefly describe a typical day in your life. Identify each time you use water. Don't forget that producing power, food, and other goods uses water.
   ::简单描述一下你生命中典型的一天。 每次使用水时, 请注明身份。 不要忘记生产电力、食物和其他商品需要水。

Think Critically
::仔细仔细思考

7. More than 70 percent of Earth's surface is covered by water. Why is scarcity of water the world's most serious resource problem?
   ::地球上超过70%的地表被水覆盖,为什么缺水是世界最严重的资源问题?

7. Relate droughts to water shortages. Explain why droughts are becoming more common.
   ::将干旱与缺水联系起来,解释为什么干旱越来越普遍。

Points to Consider
::需要考虑的要点

In this lesson, you learned that many people don't have clean water to drink. They must drink polluted water instead.
::在这个教训中,你学到很多人没有干净的水喝,他们必须喝污染的水。

• How does water become polluted?
  ::水如何受到污染?

• Can polluted water be treated so it is safe to drink?
  ::被污染的水能否处理,以便安全饮用?