用英语写一篇关于水的说明文

用英语写一篇关于水的说明文
用英语写一篇关于水的说明文

用英语写一篇关于水的说明文
World freshwater resources
Many people regard the earth as a planet blue,71% of its surface area covered with water.In fact,97.5% of the water on the earth is only 2.5% saltwater,freshwater.And in fresh water,nearly 70% frozen in the Antarctic and Greenland ice sheets,and most of the rest is moisture in the soil or groundwater,difficult to mine for human use.Rivers,lakes,reservoirs and shallow groundwater and other sources of water are easily mined directly for human use,but the insufficient number of world fresh water 1%,accounting for about 0.007% of all water on earth.The global annual landed in the mainland on the precipitation of about 110 trillion cubic meters,deduct atmospheric evaporation and plant uptake of water,river runoff in the world about 42.7 trillion cubic meters,according to the 1995 world population is calculated,to obtain the average per person per year for 7300 cubic meters of water.As the world population continues to increase,this average has been relatively dropped 1970 37%.
World water resource queue
Other countries and regions in the world due to different geographical environment,has water quantity difference.According to the water resources quantity in line,several of the former are:Brazil,Russia,Canada,China,the United States,Indonesia,Bangladesh,India.According to the population mean,is another kind of result.China water resources per capita is only equivalent to the world average of 1 / 4.
Serious water shortage in the country
World freshwater resources 65% concentrated in the 10 countries,which make up 40% of the population in 80 countries is a serious shortage of water.If a country is annual per capita consumption of 2000 cubic meters,is the water shortage in the country.In the following 1000 cubic meters of water per capita,is a serious water shortage in China,a total of 15:Egypt,UAE,Oman,Cape Verde,Burundi,Algeria,Yemen,Jordan,Saudi Arabia,Barbados,Bahrain,Singapore,Libya,Kuwait,Qatar,Malta ( annual per capita consumption of only 82 cubic meters ).China's per capita water not rich,is one of the countries that lack water.
Water resources in the future
Human demand for water grow with each passing day.The whole world 1975 water to 3 trillion cubic meters,in 1994 4.3 trillion cubic meters,in 2000 7 trillion cubic meters.Someone analysis,since 2030,world water resources are in short supply; in 2050,230000000000 cubic meters of water losses; losses in 2070,410000000000 cubic meters of water.Our expert analysis,China in 2050 the total water requirement is 800000000000 stere,than it is to add 240000000000 cubic meters.Among them,80000000000 cubic meters of city life water,industrial water 300000000000 cubic meters,420000000000 cubic meters of water use in agriculture.
Water is an important component of human adult,about body weight 60-70%.Blood in the water content of more than 90%,thus about great loss of moisture,can lead to death.We eat,devour,digestive,delivery of nutrients and excretion of waste,each link,water is essential for.Water lubrication of joints,such as water can prevent the eye is too dry,saliva and gastric juice can help digestion.Water can also regulate body temperature,through the wicking away excess heat.Drink plenty of water can also reduce urinary calcium concentration,calcium concentration is too high may lead to stone.