How much fresh water is there on Earth, and how much is there on Earth?

The total amount of water on the earth is 1.4 billion cubic kilometers, there is a lot of water on the earth, and the freshwater reserves only account for 100 million cubic kilometers of the world's total water, and some of them belong to solid glaciers, which are distributed in the high mountains and the north and south poles that are difficult to use, and some of the fresh water is buried deep underground, which is difficult to exploit. At present, only groundwater, lake freshwater and riverbed water can be directly used by human beings, and the sum of the three accounts for about the total amount of water on the earth. At present, the amount of freshwater resources used by human beings is getting larger and larger, and excluding the deep groundwater that cannot be extracted, the actual amount of water that human beings can use is only about about the total amount of water on the earth.

To date, human freshwater consumption accounts for 54% of the world's available freshwater consumption. However, the problem of freshwater pollution has not been completely eliminated. Therefore, the protection of water quality and the rational use of freshwater resources have become major issues of general concern to mankind today.

China's total freshwater is trillions of cubic meters, ranking sixth in the world, but the per capita water volume is only 2,400 cubic meters, which is 1 4 of the world's per capita water volume, ranking 121st in the world, and one of the 13 poorest water countries.

Freshwater accounts for 19 percent of total water resources

A: There are about 1.3 billion cubic meters of water on Earth.

Help the upstairs to replenish it.

Potable fresh water accounts for about 1% of the total fresh water.

EarthFreshwater resourcesThat's just about 3 percent。The oceans make up about 10 percent of the Earth's total water. Freshwater on land accounts for only 10 percent of the total amount of water, with glaciers accounting for 10 percent of freshwater on land.

Lakes are saltwater and groundwater are brackish. Water on Earth can exist in liquid, solid, gaseous form.

The total amount of freshwater resources in our country:2,800 billion cubic meters, accounting for 6% of the world's water resources, ranking fourth in the world after Brazil, Russia and Canada. However, China's per capita water resources are only 2,300 cubic meters, only a quarter of the world average, and it is one of the poorest countries in the world in terms of per capita water resources.

The Earth's freshwater accounts for about the total amount of water on the planet.

The earth's water storage is very abundant, with a total of 100 million cubic kilometers, but there is very little fresh water that can be directly used by people for production and life. More than 70% of the scarce freshwater resources are frozen in the Antarctic and Arctic ice caps, and 87% of the freshwater resources are unusable due to the inaccessible mountain glaciers and permafrost snow. The freshwater resources that humans can really use are some of the rivers, lakes and groundwater, which account for about the total amount of water on the planet.

Status of freshwater resources

Worldwide, the top countries in terms of water reserves are: Brazil, Russia, the United States, Indonesia, Canada, China, Bangladesh, India, Venezuela, and Colombia. Our country is a country with severe drought and water shortages.

Although China's total freshwater resources are 2.7 trillion cubic meters, accounting for 6% of the world's water resources, ranking sixth in the world, China has a population of 1.3 billion, and its per capita freshwater resources are lower than the world average.

Water resources in the broad sense refer to the water on the surface of the earth that can be used by humans, while water resources in the narrow sense are freshwater that can be used directly by humans. Seawater accounts for the total reserves of water on the planet, and only freshwater. Icebergs and glaciers account for the proportion of freshwater resources.

Water in groundwater and soil, water in lakes and swamps, water in rivers, and water in the atmosphere of the blind state.

Water is cyclical in nature. The amount of water circulating on Earth is roughly 420,000 cubic kilometers per year, of which about 100,000 cubic kilometers land on land. After that, about 40,000 cubic kilometers of water flow into the ocean through rivers.

Shallow groundwater. These freshwater reserves account for only 7/100,000 of the world's total freshwater, that is, about 9,000 cubic kilometers of freshwater resources are actually used effectively in the world every year.

Antarctica, the world's most abundant freshwater resources continent, has an area of 14 million square kilometers, more than 95% of the area is covered by ice and snow all year round, forming a huge and thick ice sheet, its average thickness is 2450 meters, the total amount of ice and snow is about 27 million cubic kilometers, accounting for more than 90% of the world's total ice and snow, and storing 72% of the world's available fresh water.

Freshwater 2 100

There is a lot of water on Earth, and the total volume of water is estimated to be about 13.8 billion cubic kilometres. If this water is evenly distributed on the earth's surface, it is equivalent to the entire surface of the earth being covered with a layer of water with an average depth of 2,650 meters. Unfortunately, this water98 is saltwater, mainly found in the ocean.

Fresh water only accounts for 2 of the total water of the earth, about 30 million cubic kilometers, and the fresh water of these 2 can not be all used by human beings, because 88 of it is frozen in the ice caps and glaciers at the poles, and the remaining 12 that is, rivers, lakes and shallow groundwater that can be exploited can be used by human beings, and the vast majority of them are groundwater, and the water in rivers and lakes that cannot be applied without exploitation and can be directly applied only accounts for 0 04 of the total amount of fresh waterWater on Earth is always in flux, with water from the oceans and lands evaporating into the atmosphere, and then falling back to the earth as rain or snow, nourishing all things, replenishing rivers, lakes or flowing into the sea. Water can also seep into the ground and sink into underground aquifers.

Extremely deep groundwater cannot be replenished or extracted, and is known as primary water and therefore cannot be regenerated. As a result of this fluid nature of water resources, landlogging or drought results in an uneven distribution of water resources, about 65 of the world's water resources are concentrated in 10 countries each year, while 80 countries with a combined population of 40 (9 of which are in the Near and Middle East) are severely water scarce, and another 26 countries (with a total population of 230 million people) have very little water resources. We call these countries water-scarce countries.

The international standard for water-scarce countries is based on Sweden.

Hydrologists Marin and Falkenmark define a country with less than 1,700 tonnes of renewable freshwater per person per year, then the country is regularly or often in a state of low water; If the amount of water per person per year is less than 1,000 tons, then there will be a shortage of water. At present, there are 15 countries with an average annual water of less than 1,000 cubic meters per person.

With only 82 cubic metres per capita per year, Malta has the highest water scarcity among these countries. Apart from Malta, Qatar is the most water-scarce country.

91 cubic meters per capita per year), Kuwait.

95 cubic meters), Libya (111 cubic meters), Bahrain (162 cubic meters), Singapore (180 cubic meters), Barbados (192 cubic meters), Saudi Arabia.

249 cubic meters), Jordan (318 cubic meters), Yemen (346 cubic meters), Algeria.

527 m3), Burundi (594 m3), Cape Verde (777 m3), Oman (874 m3), United Arab Emirates.

902 cubic meters), Egypt (936 cubic meters).Water is expected to be more expensive than oil in these countries by the middle of the 21st century, with Malta as per capita at 68 cubic metres per year.

The total amount of water on the earth is 1.4 billion cubic kilometers, there is a lot of water on the earth, and the freshwater reserves only account for 100 million cubic kilometers of the world's total water, and some of them belong to solid glaciers.

The total mass of the Earth's oceans is about tons, which is equivalent to 1 4400 of the total mass of the Earth. The ocean covers an area of square kilometers, with an average depth of 3,682 meters and a total volume of about cubic kilometers. If all the Earth's surfaces were at the same altitude and were a smooth spherical surface, the average depth of the Earth's oceans would be kilometers.

Water is the most abundant natural substance on the earth's surface, covering more than 70% of the earth's surface area. But the earth's freshwater accounts for only a large amount of water, and 70% of the freshwater is solid water, stored in the Arctic and Antarctic and snowy peaks; is groundwater; Fresh water that can be easily used by humans only accounts for about a large number of people. More than 2 billion people in 80 countries are now facing water scarcity.

In many countries in the Middle East and Africa, per capita water resources are below the 1,000 cubic meters per person-year. In Kuwait, desalination of seawater is as expensive as producing oilIn the future, once a global water crisis breaks out, a drop of water will be worth as much as a drop of blood, and the dispute over water will be the trigger for a global war.

Water shortage is a major challenge facing mankind in the 21st century.

The amount of water on Earth is distributed in such a way that oceans account for icebergs and glaciers, groundwater, lakes, and the atmosphere (water vapor), while rivers and streams account for only.

Of these, only fresh water from groundwater, lakes, rivers and streams can be used by people, animals and plants, which means that the amount of water that the earth can supply to life on land is less than 1% of its total waterIt can be seen that freshwater resources are limited and precious, and their pollution will further reduce the amount of freshwater available for plants, animals and humans, thus directly affecting the survival of life on earth.