water distribution

conflicts over water

As water supplies become scarce, conflicts will arise between the individuals or nations that have enough clean water and those that do not (Figure 1.3). Some of todays greatest tensions are happening in places where water is scarce. Water disputes may add to tensions between countries where differing national interests and withdrawal rights have been in conflict. Just as with energy resources today, wars may erupt over water. Water disputes are happening along 260 different river systems that cross national boundaries. Some of these disputes are potentially very serious. International water laws, such as the Helsinki Rules, help interpret water rights among countries. Many regions already experience water scarcity. This map shows the number of months in which the amount of water that is used exceeds the availability of water that can be used sustainably. This is projected to get worse as demand increases.

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water scarcity

Water scarcity can have dire consequences for the people, the economy, and the environment. Without adequate water, crops and livestock dwindle and people go hungry. Industry, construction, and economic development is halted, causing a nation to sink further into poverty. The risk of regional conflicts over scarce water resources rises. People die from diseases, thirst, or even in war over scarce resources. Californias population is growing by hundreds of thousands of people a year, but much of the state receives as much annual rainfall as Morocco. With fish populations crashing, global warming, and the demands of the countrys largest agricultural industry, the pressures on our water supply are increasing. Click image to the left or use the URL below. URL: Click image to the left or use the URL below. URL:

effect of changing climate

Global warming will change patterns of rainfall and water distribution. As the Earth warms, regions that currently receive an adequate supply of rain may shift. Regions that rely on snowmelt may find that there is less snow and the melt comes earlier and faster in the spring, causing the water to run off and not be available through the dry summers. A change in temperature and precipitation would completely change the types of plants and animals that can live successfully in that region.

water shortages

Water scarcity is a problem now and will become an even larger problem in the future as water sources are reduced or polluted and population grows. In 1995, about 40% of the worlds population faced water scarcity. Scientists estimate that by the year 2025, nearly half of the worlds people wont have enough water to meet their daily needs. Nearly one-quarter of the worlds people will have less than 500 m3 of water to use in an entire year. That amount is less water in a year than some people in the United States use in one day. Some regions have very little rainfall per month.

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droughts

Droughts occur when a region experiences unusually low precipitation for months or years (Figure 1.2). Periods of drought may create or worsen water shortages. Human activities can contribute to the frequency and duration of droughts. For example, deforestation keeps trees from returning water to the atmosphere by transpiration; part of the water cycle becomes broken. Because it is difficult to predict when droughts will happen, it is difficult for countries to predict how serious water shortages will be each year. Extended periods with lower than normal rainfall cause droughts.

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water distribution

Water is unevenly distributed around the world. Large portions of the world, such as much of northern Africa, receive very little water relative to their population (Figure 1.1). The map shows the number of months in which there is little rainfall in each region. In developed nations, water is stored, but in underdeveloped nations, water storage may be minimal. Over time, as population grows, rainfall totals will change, resulting in less water per person in some regions. In 2025, many nations, even developed nations, are projected to have less water per person than now

instructional diagrams

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questions

water may cause the next war because

-->  a) large regions receive much less water relative to their population.

b) water breakdown is a new alternative energy source.

c) developed nations use so much water that they need to get it from underdeveloped nations.

d) none of these.

which of the following is not true about water scarcity?

a) in 1995, about 40% of the worlds population faced water scarcity.

b) the amount of water people in water scarcity have is less than some people in the u.s. use in a year.

c) people in water scarcity die from thirst, hunger and diseases more than other people.

-->  d) water scarcity is defined as the state in which people do not have enough water to meet

a region is said to be in drought when

a) it receives an average of less than 10-inches of rain each year for months or years.

b) plants die and the ground dries out.

-->  c) it experiences low precipitation for that region for months or years.

d) animals die of thirst and lack food.

the central valley of california is a lush agricultural area because it receives a lot of rain.

a) true

-->  b) false

a change in temperature and precipitation would completely change the types of plants and animals in a region.

-->  a) true

b) false

which of these is not a possible effect of global warming?

a) patterns of rainfall may change so that agricultural land may no longer get enough rain.

b) snowmelt may no longer be available to get water to a region through a long, hot summer.

c) the plants and animals that live in the region may die out or shift locations.

-->  d) all of the planet will experience drought at the same time.

water scarcity is

a) a region not receiving enough rain.

-->  b) a region not receiving enough water to meet its peoples needs.

c) a region that chops down all of its trees.

d) a region that goes to war over water.

some regions receive a considerable amount of rain, but have an annual drought of several months each year.

-->  a) true

b) false

water disputes are easily solved using the helsinki rules.

a) true

-->  b) false

diagram questions

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