China s total freshwater and per capita share?

The current state of water resources.

Water is the lifeblood of agriculture, as well as the lifeblood of the entire national economy and human life. The status and utilization level of water resources have become important indicators to evaluate the sustainable economic development of a country and a region. China is a relatively poor country with water resources, with an average annual precipitation of 630 mm, which is lower than the precipitation of the global land surface and the Asian land surface. The total annual average freshwater resources are trillions of m3, and the per capita water share is only 2 300 m3, which is only equivalent to 1 4 of the world's per capita level, ranking 109th in the world, and one of the 13 countries with the poorest per capita water resources in the world. The water resources of cultivated land are 28 500 m3 hm2, which is 4 5 of the world average.

In addition, the spatial and temporal distribution of water resources in China is seriously unbalanced, with more precipitation in the southeast and less in the northwest, more in the mountainous areas and less in the plains, and the rainfall decreases roughly from southeast to northwest. 81% of the water resources are concentrated in the Yangtze River basin and the south of the Yangtze River, the population and cultivated land in the north of the Yangtze River account for the sum of China, but the water resources only account for 19% of the country, and the per capita occupancy is 517 m3, which is equivalent to 1 5 per capita in the country and 1 20 in the world per capita. In particular, large areas of the Gobi Desert in Xinjiang, Qinghai and other places in the arid areas of northwest China have no irrigation, so there is no agriculture.

The precipitation is unevenly distributed in the year, with little rain in winter and spring, more rain in summer and autumn, and the rainfall in the flood season is too concentrated, often in the form of heavy rain, which is very difficult to utilize, and the amount of water is lacking in the non-flood season. The amount of precipitation varies greatly from year to year, and there is a huge difference between wet years and dry years, so that flood and drought disasters occur frequently, and even drought and flood sometimes occur one after another in the same area, alternating into disasters.

2 Current status of water use in agriculture.

In terms of the country's total demand for water resources, in the event of a moderate drought, the country's total water demand is about 550 billion m3 and the water shortage is about 25 billion m3. If we take into account the unreasonable water supply factors such as over-exploitation of groundwater and direct irrigation of sewage exceeding the standard, the actual water shortage in the country is between 30,040 billion m3. Agriculture is a major water user in China, accounting for about 73% of the country's total water consumption, but the effectiveness is very poor, the waste of water resources is very serious, the effective utilization rate of water in canal irrigation areas is only about 40%, and the well irrigation area is only about 60%, and the production of grain per m3 of water is less than 1 kg.

However, the effective utilization rate of water in some developed countries can reach more than 80%, and the production of grain per m3 of water is generally more than 2 kg, of which Israel has reached kg. This shows that the comprehensive application of various water-saving agricultural technologies in China is still very low, and there is still a big gap compared with developed countries. At the same time, it also allows us to see the great potential and broad prospects for the development of water-saving agriculture in China.

Water China's total water resources are 2.8 trillion cubic meters, and the current use of water resources has accounted for 1.5 percent of the total, and its development and utilization has exceeded that of any country in the world. China's total groundwater resources are 870 billion cubic meters, of which 200 billion cubic meters can be exploited and 88 billion cubic meters have been exploited. All in all, China is a water-scarce country, with per capita water resources only 1 4 per capita in the world, 1 7 in the former Soviet Union, and 1 3 in the United States.

According to **, by the 20s of the next century, the average water resource owned by Chinese was only 1,800 cubic meters.

Freshwater accounts for the world's total water volume.

About 71% of the earth's surface is covered by water, the total amount of water on the earth is 1.4 billion cubic kilometers, the ocean accounts for about the total amount of water on the earth, and the terrestrial freshwater only accounts for the total water, of which glaciers account for the terrestrial freshwater, lakes and underground saltwater occupy.

Nearly 70% of the Earth's freshwater is fixed in the ice of Antarctica and Greenland, and the rest is mostly soil moisture or deep groundwater, which cannot be used by humans, and less than 1% of the Earth's freshwater or about the water can be used directly by humans.

The state of freshwater resources in China.

The total amount of freshwater resources in China is relatively large, but it is very low in terms of population and average occupation of cultivated land. Compared with many countries in the world, China's freshwater resources problem is more serious, although China's total river runoff ranks sixth in the world, but due to China's vast territory and large population, the per capita and per mu occupancy are lower than the world average.

Freshwater pollution has spread across the country. In terms of per capita freshwater resources, China's water shortage mainly refers to the northern region, then the pollution of freshwater resources is a national problem. Moreover, the more water-rich and large cities are, and the more densely populated the areas, the more polluted they tend to be.

Total amount of freshwater resources in China: Freshwater resources are what we usually call water resources, which refers to freshwater resources on land. It is made up of water from rivers and lakes, mountain snow, glaciers, and groundwater.

Without water, there is no life.

Only three percent of the earth's water is freshwater, all terrestrial life depends on freshwater in the final analysis, it determines the distribution of life on the earth, water vapor rises from the sea, is buried by the wind to the inland, with the increase of the altitude of the spike rolling ants, converges into clouds, forms rainfall, which is also one of the basic ** of freshwater, streams converge to form a galloping river, carving out many wonders of nature, the river provides many wildlife habitats along the river, giving birth to rich species, whether it is high mountains, or the bottom of the lake, Where there is fresh water, there is life.

In the 21st century, the contradiction between supply and demand of water resources in China has further intensified. According to **, in 2010, the total water supply of the country was 6200 650 billion m3, and the corresponding total water demand will reach 730 billion m3, and the gap between supply and demand is nearly 100 billion m3, and the total water demand of the country will reach 1 trillion m3 in 2030, and the country will have a water shortage of 4000 450 billion m3. In other words, in the next 30 years, the water supply will increase by 400 450 billion m3, which is a very difficult task to accomplish.

1. The total amount of fresh water on the earth is about 100 million tons, which is the total amount of water on the earth. However, this limited amount of freshwater is found in several forms of solid, liquid and gaseous forms in terrestrial glaciers, groundwater, surface water and water vapour, with polar glaciers accounting for 75% of the Earth's total freshwater, which is almost unusable.

2. Groundwater accounts for 8,600 trillion tons of the earth's total freshwater, but half of the groundwater resources are at a depth of less than 800 meters, which is difficult to exploit.

3. Rivers and lakes account for 230 trillion tons of the earth's total fresh water, and are the main source of water resources for plants, animals and humans on land.

4. The amount of water vapor in the atmosphere is 13 trillion tons of the total amount of fresh water on the earth, which replenishes the land with fresh water in the form of rainfall.

China's per capita freshwater resources account for 1.5 percent of the world's per capita freshwater resources.

China's per capita freshwater resources account for a very low proportion of the world's per capita freshwater resources, with the global average per capita water resources being 5,850 cubic meters per year, while the Chinese's per capita water resources are only 1,700 cubic meters per year, only about one-third of the world average, and it is one of the 13 water-poor countries in the world.

At present, the world's freshwater resources account for only 70% of its total water, of which more than 70% are frozen in the ice caps of the Antarctic and the Arctic, and 86% of the freshwater resources are difficult to use, together with the unusable mountain glaciers and permafrost snow. Only three percent of the earth's water is freshwater, all terrestrial life depends on freshwater in the final analysis, it determines the distribution of life on the earth, water vapor rises from the sea, is carried inland by the wind, and with the increase in altitude, it gathers into clouds and forms rainfall, which is also one of the basic freshwater.

Measures to conserve water resources

1. To protect water resources, we must first mobilize the whole society to change the traditional concept of water use. It is necessary to make everyone realize that water is precious, and that the water used for each flush of the toilet is equivalent to the daily per capita water consumption of some developing countries. Taking a cool shower in the summer uses the same amount of water as dozens of people in a water-scarce country use every day.

2. Water resources must be rationally developed to avoid the destruction of water resources. The development of water resources includes the development of surface water resources and the development of groundwater resources. When extracting groundwater, it should be extracted in layers because the water quality of each aquifer varies greatly.

3. Do not mix the polluted diving and confined water; For the exploration projects that expose and penetrate the water layer, it is necessary to strictly do a good job of layered water stopping and sealing holes in accordance with the relevant regulations, so as to effectively prevent water pollution and ensure that the water body itself continues to develop and develop.

The total amount of freshwater on the planet is about 100 billion tons, which is the total amount of water on the planet.

Freshwater resources as a percentage of the Earth's water resources are: nearly 3%. 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. Lakes with brackish water and underground brackish water occupy.

Only one of the world's freshwater resources can be directly used by humans.

Our country is a country with severe drought and water shortages. Although China's total freshwater resources are 2.7 trillion cubic metres, accounting for 6 per cent of the world's water resources and ranking sixth in the world, China's population is 1.3 billion and its per capita freshwater resources are lower than the world average.

In the world, Lu Shibo ranks according to the size of water reserves, and the top countries are: Brazil, Russia, the United States, Indonesia, Canada, China, Bangladesh, India, Venezuela, and Colombia.

The world's most abundant freshwater resources for Antarctica, Antarctica 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 of 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, storing 72% of the world's available fresh water.

China's top five freshwater lakes are ranked from largest to smallest.

First place: Poyang Lake (3,960 square kilometers).

It is located in the northern part of Jiangxi Province, on the south bank of the Yangtze River in China. The Jiangxi province where Poyang Lake is located covers an area of 3,960 square kilometers, with an area of about 160,000 square kilometers, which means that Poyang Lake is almost one-fortieth the size of Jiangxi Province.

Second place: Dongting Lake (2,691 square kilometers).

Dongting Lake, known as Yunmeng, Jiujiang and Chonghu in ancient times, was named after Dongting Lake in the lake during the Spring and Autumn Period and the Warring States Period. It is located in the north of Hunan Province, on the south bank of the Jingjiang River in the middle reaches of the Yangtze River, spanning Yueyang, Miluo, Xiangyin, Wangcheng, Yiyang, Yuanjiang, Hanshou, Changde, Jinshi, Anxiang, Nanxian and other counties and cities.

Third place: Taihu Lake (sq km).

It was known as Zhenze and Qiqu in ancient times, and was also known as Wuhu and Lize. It straddles Jiangsu and Zhejiang provinces, bordering Wuxi in the north, Huzhou in the south, Yixing in the west, and Suzhou in the east. Crisscrossed by Lake Tai, there are many estuaries, and more than 50 major rivers flow into and out.

Fourth place: Hongze Lake (2069 square kilometers).

It is a shallow lake with a depth of 4 meters and the highest meter. The lake is 65 kilometers long, with an average width of kilometers and a water area of 1,597 square kilometers. It is the largest plain reservoir lake in China.

Originally, it was a group of shallow lakes, which were called Fuling Lake in ancient times, Pohu Pond after the Han Dynasty, Hongze Lake in Sui, and Hongze Lake in Tang.

Fifth place: Chaohu Lake (square kilometers).

Located in the central part of Anhui Province, surrounded by Hefei, Chaohu, Feidong, Feixi, Lujiang and other cities and counties, it belongs to Hefei and is connected with the Huai River. It is 55 kilometers long from east to west, 22 kilometers wide from north to south, with a perennial water area of 760 square kilometers, an average water depth of 289 meters, and a volume of 100 million cubic meters. It is one of the five major freshwater lakes in China, like a precious mirror embedded in the Jianghuai.