Japan Water Guard
|●To conserve 21st century environment and water front●
Save our Earth！！
− Contents −
１．Basic of Water
§１．Water and the Earth
Chapter１ Basic of Water
Water covers 70 % of the surface of the earth. The volume of water is 14 hundred million km3. Thus, the earth floating in space is regarded as "watery planet." Human lives relying on water, and it seems that there is no need to worry about lack of water if you look at the earth from space. However, 97% water on the surface of the earth is sea water. Sea water itself is not suitable for drinking water nor daily water. Therefore, 60 hundred million people in the earth rely on thre rest of only 3% of earth water. Even 70% in this 3 % water can not be used since it is ice, snow, or water vapor. If subtract to these water, water in rivers, lakes, marshes, and underground which we can use is only 0.8 %. Furthermore, we must share these water with other living things, so we can only use very little water.
Water amount on the earth has change little from time immemorial. Although the place where it rains might change, rain amount is almost stable every year. Water from the earth surface becomes moisture vapor, it stays in the earth's atmosphere. After it is cooled down, it falls down on the earth as rain or snow. Rain water washes out the grand or sinks in underground. After several processes, it enters into the ocean, and then becomes moisture vapor again. Vapored water doesn't spread out in the earth's atmosphere, but becomes rain so that comes back as the earth water. Water around us has been in the cycle from time immemorial. Therefore, if we pollute the water, it means that it has large effects on our future children.
Human lives have taken places around water front. As ancient civilization has flourished in the Yellow rivers, the Indus river, and Tigris・Euphrates river, humans have lived with water. Drinking water which people needs is 2 liters per day, so 1m3 water for one person is enough for one year. However, in reality, 330 liters water is used per one day, so 120m3 water is used for one year. Thus, we need 120 times more daily life water than drinking water. Water serves as a barometer for culture. More water is used in more developed cultures. The use of water in buildings, hospitals, hotels, and companies increases so that more water is required. Furthermore, water is need 10 times more for food production. Water is not only needed rice and wheat cultivation, but also required for cows' grain. For 1kg cows meat, 13 times more grains are consumed, and for the grains, 20m3 water is needed. In summing of these water, one person in developed countries use more than 1000m3 water for one year.
The earth is currently facing serious water issue. One of them is desertification. Not only in Africa where is known as deserts, desertification is progressing in China and middle parts of America. Although global warming is regarded as the factor of desertification, other anthropogenic factors are reported. That is development of agriculture and industry which use lots of underground water. In its background, there is rapid population growth, and large lands areas and forests have been used to produce foods. Underground water which has been stored for hundreds and one thousands years are carelessly used by humans. Thus drought and desertification have been reported in many places. Abnormal phenomenon such as drought occurred in Great Lakes in the border between America and Canada, Aral sea in Russia, the Yellow River.
In all the countries of the world, conflicts against international rivers have endlessly occurred. If countries located in upper stream of river construct dams, the amount of water for other countries in downstream decreases. Also, water pollution in upper stream seriously affects on countries in downstream. Moreover, since rapid development of agriculture and industry occurred in developing countries, there are issues that water sourse drained and water level of underground water decreases. Although it is best to peacefully discus about the issue between countries, there is risk of water against the conflict.
"The 20th century is war for oil, but it will be war against water in the 21st century."
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