Water resources problem

The so-called water resources refer to all surface water and groundwater resources that can be used for production and life now or in the future. Water resources are an important part of natural resources. The total reserves of water on the earth are about 65.438+0.36 billion (cubic kilometers), of which seawater accounts for 97.3% and fresh water only accounts for 2.59%. Icebergs and glaciers account for 77.2% of fresh water resources, 22.4% of groundwater and soil water, 0.35% of lake and swamp water, 0.0 1% of river water and 0.04% of atmospheric water. The only available fresh water is river water, fresh lake water and shallow groundwater, which is estimated to be about 3 million (cubic kilometers), accounting for only about 0.2% of the total water volume of the earth. Water circulates in nature. The amount of water circulating on the earth every year is about 420,000 (cubic kilometers), of which the land is about 6,543,800+10,000 (cubic kilometers), and the amount of water flowing into the ocean through rivers is about 40,000-45,000 (cubic kilometers).

Rivers and lakes are the main fresh water resources in China. China's per capita runoff is 2200 cubic meters, which is 24.7% of the world's per capita runoff. The distribution of water resources in China is more in the south and less in the north.

Present situation and potential analysis of water resources utilization in Zhejiang Province

The average water resources in Zhejiang Province for many years is 95.5 billion m3, and the per capita water resources is only 2060 m3, which is 8% lower than the national average. The actual available water resources in Zhejiang Province are 3 1 100 million m3, and the per capita available water resources are 700 m3, all of which are replenished by rainfall. According to the weather and climate characteristics and the analysis of the historical average precipitation distribution in Zhejiang Province, the precipitation in Zhejiang Province is mainly concentrated in the rainy period from May to early July and the typhoon drought period from July to September (affected by typhoons). The precipitation in this period is often heavy rain, with much rain loss and low water storage rate. Precipitation has the characteristics of uneven geographical distribution, obvious drought and flood, strong randomness, uneven distribution within the year, uneven regional distribution of water resources and water demand in economic regions. At the same time, the river sources in the province are short and fast, and a large amount of runoff flows into the East China Sea in the form of floods.

1, total water resources

Zhejiang province belongs to a typical subtropical monsoon climate, with an average annual precipitation of 1200-2200mm, which belongs to the humid area of China. The average total amount of water resources is about 95.5 billion cubic meters, which is rich in water resources. However, our province is densely populated, with a per capita possession of only 2060m3, which is close to the international warning line of moderate water shortage of 2000m3 per capita.

Table 2-3 Rainfall and Surface Water Resources in Different Watershed of the Province

Watershed division

deposit

Surface water resources (100 million cubic meters)

millimetre

Billion cubic meters

Lake system in Pan Yang

1905.9

9.72

6.0 1

Taihu coast

1323.5

162.26

67.7 1

Qiantang River

1648. 1

525.85

29 1.4 1

Puyang River, Caoe River, Yongjiang River and coastal rivers in eastern Zhejiang

148 1.3

33 1.43

174.57

Jiaojiang, Oujiang and coastal rivers in southern Zhejiang

1730.6

58 1.83

355.3 1

East Fujian River

1932

23.97

16.02

the Minjiang River

1836.9

22.08

12.96

The whole province

1607. 1

1657. 14

923.99

According to the data of Zhejiang Water Resources Bulletin

The area of rivers and lakes in Zhejiang province accounts for 6.4% of the total area of the province. The whole province can be divided into Pan Yang River System, Taihu Lake Coast, Qiantang River, puyang river, Cao E, Yongjiang River and coastal rivers in eastern Zhejiang, Jiaojiang River, Oujiang River and coastal rivers in southern Zhejiang, and Mindong and Minjiang River. See Table 2-3 for precipitation and surface water resources in each basin. Table 2-4 shows the distribution of water resources by administrative divisions. As can be seen from the data in the table, the regional distribution of water resources in Zhejiang Province is uneven, especially the total amount of water resources in economically developed areas is relatively lacking, while the precipitation in the economically underdeveloped southwest mountainous areas is relatively rich and the total amount of water resources is relatively rich.

The water wasted by car washing is enough for 6,543,800,000 Shanghainese to use for 20 days.

"Shanghai Linjiang is near the sea, so it is impossible to lack water!" In the impression of most people, Shanghai is rich in seawater resources, but in fact, due to serious pollution, only 20% of Shanghai's surface water resources are available, and the per capita water resources are less than 200 cubic meters, which is lower than that of Beijing. This is a typical polluted city that is extremely short of water.

In the interview, the reporter found that many enterprises and individuals have a weak awareness of water conservation because they don't understand the basic knowledge of water and the situation of water resources. They think that water prices are cheap and there is not much money to use more water. The phenomenon of wasting water in production, consumption and life is widespread.

Take the car wash industry in Shanghai as an example. As a new consumption hotspot in megacities, the number of motor vehicles in Shanghai has reached 6.5438+0.5 million, and it is expected to reach 3 million by 2065.438+00. With the increase of the number of motor vehicles, the car washing industry has developed rapidly.

According to the statistics of Shanghai Water Affairs Bureau, about 70% gas stations in Shanghai have motor vehicle cleaning, about 550 to 600; 3 15 washing stations (points) with business licenses; There are about 300 unlicensed car wash stalls. The total annual water consumption of washing stations (points) is about 6.5438+million cubic meters. Among thousands of washing stations (points), only 8 have installed and used motor vehicle sewage recovery and purification systems. Although the washing stations of large bus companies have the ability to recycle car washing water, most of them still use manual washing with high water consumption because the car washing facilities are not suitable for the bus structure and the cost of mechanical car washing is high.

It is estimated that the average water consumption for cleaning a car is 70 liters to 80 liters. If the car wash water recycling facilities are used, the water consumption can be reduced to 15 liters to 20 liters. According to the calculation of washing cars 50 times a year for 1 10,000 vehicles in the city, it can save nearly 3 million cubic meters of water for car washing in the city every year. In other words, at present, only the water wasted by the car wash industry can supply 1 10,000 Shanghai people with 20 days' domestic water.

In Beijing, where water resources are also scarce, in addition to the larger car washing industry created by more than 2.3 million motor vehicles, the waste of water resources caused by water leakage in urban pipe networks is also amazing. Statistics from Beijing Water Affairs Bureau show that the leakage rate of the city's pipe network is nearly 20%, wasting water supply 1/5. The annual water loss in Beijing is equivalent to 13 of the North Sea.

Zhao, a member of the Chinese People's Political Consultative Conference and a counselor of the Shanghai Municipal Government, said: "If we don't change the embarrassing situation of' what we lack is what we waste' as soon as possible and realize the economical, rational and efficient use of resources, these resource-consuming megacities will consume their own development prospects."

Since the beginning of history, human beings have lived on weeds. Water is the lifeblood of human survival and development, which determines people's living environment, health level and quality of life, and determines the development direction and rise and fall of the country. Let's join hands to save water and cherish our home!

Finally, I send you a little poem:

A drop of water, a dot,

An ant drank it for a year.

Ten drops of water, one line,

Two ants can row a boat.

Students, don't waste it,

Don't let the faucet shed tears.

Many regions and countries in the world are troubled by water, and even have conflicts for the control of water resources. Israel in the Middle East has been in a state of war since its founding. Its competition for water resources is an important factor in the conflict with Arab countries. Because Israel is located in the desert, it is dry and lacks rain, and the freshwater resources it relies on are mainly two international rivers: Jordan River and Euphrates River. Whoever controls the water source will be strong. Therefore, the Israeli Prime Minister once declared: "Water is the life of Israelis, and we will consolidate our continuous control over the Jordan River with practical actions!" 1979, the Egyptian president once said that "there is only one thing in the world that can make Egypt go to war again, and that is water."

According to statistics, there are 426 billion tons of untreated industrial wastewater and sewage in the world every year. In China, more than 82% of rivers and lakes are polluted to at least the same degree, which leads to various pollution accidents. For example, during the Spring Festival of 1999, the sluice of Xianyitan Water Control Project in Guigang, Guangxi was closed for water storage, and the downstream water volume was greatly reduced, and the river's self-purification ability was weakened, resulting in pollution accidents, more than 30,000 kilograms of dead fish and direct economic losses of 10 million yuan. Many fish farmers looked at the glistening dead fish and knelt down and cried.

Water pollution comes from the arbitrary discharge of industrial wastewater, waste residue and domestic sewage; Arbitrary use and abuse of chemical fertilizers and pesticides in agricultural production. Domestic sewage mainly comes from the pollution of chemical detergents, especially the pollution of phosphorus-containing washing powder. When the phosphorus content in the environmental water exceeds the standard, algae will grow wildly in the water, making the water worse and anoxic, and reducing the transparency, that is, eutrophication. In detergents, phosphorus-containing substances can also make olfactory cells such as fish lose their functions, thus losing their ability to prey and resist foreign aggression and dying.

, water resources

Precipitation in 2002, the city's precipitation was 1488.6 mm (equivalent to 8.659 billion cubic meters of water), which was 8.3% more than the average precipitation for many years and 12.5% more than the previous year's precipitation (7.694 billion cubic meters). The average annual precipitation in Huzhou, Deqing, Changxing and Anji counties is 1476.2, 1552.4, 1335.5438+0 and1583.5mm respectively. It is 16.9%, 1 1.8%, 2.0% and 4.9% higher than the multi-year average respectively. It increased by 19.6%, 15.5%, 7. 1% and 9.7% respectively over the previous year.

Distribution of precipitation in the year: the precipitation in non-flood season accounts for 36.5% of the whole year, which is 25.0% higher than the average of the same period in many years, of which 1 and March are 8.8% higher and 5. 1% respectively, and February is 29.4% lower, and 10 is basically the same. The average precipitation in flood season is the same as that in many years, with the precipitation in April, May and August being 84.6%, 48.5% and 14 respectively. L%, the precipitation in June, July and September is 28.9%, 28.6% and 54. 1% less than that in the same period of many years respectively.

The general trend of regional distribution of precipitation in our city is to increase with the elevation of terrain from northeast to southwest. In 2002, the variation range of precipitation in the whole city was 1300- 1800 mm, and the annual maximum precipitation was 2025.438+0mm at Dongling Station in Anji County. The annual minimum precipitation of Changxing Port Station is1245.6mm.. The annual precipitation in the upper reaches of Laoshikan Reservoir is above 1800 mm, which is the highest area in the city. The annual precipitation in the upper reaches of Hekou Reservoir and Pumice Reservoir also reaches1700 mm; Annual precipitation in urban areas and Hangjiahu Plain1400-1500mm; The annual precipitation in Changxing County is between1300-1500mm.

On June 19, 2002, Meihua entered the city, and on July 10, the average amount of plum rain in the city was 184.5 mm, and the precipitation was evenly distributed in time and space.

Surface water resources In 2002, the temporal and spatial distribution of surface water resources in the city was basically consistent with precipitation, and the runoff depth varied between 60-1100 mm. The surface water resources in the city were 4.527 billion cubic meters, equivalent to the runoff depth of 778.3 mm, which was 26.0% higher than the average of 3.593 billion cubic meters for many years. Compared with the previous year (321.800 million cubic meters), it increased by 40.7%. The surface water resources in Huzhou, Deqing, Changxing and Anji counties are 1 1.7 1, 7.92, 9.1,1.653 million cubic meters respectively.

The city's groundwater resources are10120,000 cubic meters (869 million cubic meters). Among them, there are 7170,000 cubic meters in Tiaoxi mountain area (calculated area: 4,322.3 square kilometers) and 295 million cubic meters in Hangjiahu plain area (calculated area: kloc-0/494.7 square kilometers). The groundwater resources in Huzhou, Deqing, Changxing and Anji are 2.92, 1.76, 2 1.2 and 332 million cubic meters respectively.

Total amount of water resources In 2002, the total amount of water resources in the city was 4.67 billion cubic meters, 26.0% more than the average for many years and 40.0% more than the previous year. The water yield coefficient is 0.54 and the water yield modulus is 802,900 m3/km2. The total water resources of Huzhou City, Deqing County, Changxing County and Anji County are 12.75438+0, 8.35, 9. 1 1,165.3 billion cubic meters respectively. It is 53.7%, 36.9%, 265,438+0.6% and 8.8% higher than the multi-year average respectively. Increase by 60.3%, 47.3%, 30.3% and 29.3% respectively.

The second is water storage performance and water inflow and outflow.

At present, there are 3 large reservoirs and 5 medium-sized reservoirs in our city, with a total storage capacity of 654.38+70.98 million cubic meters by the end of 2002, an increase of 0.56 1.8 million cubic meters over the previous year. The water storage capacity of river network increased by15.3 million cubic meters, and the underground stagnant water increased by 89.33 million cubic meters.

Our city is located in the lower reaches of Dongtiaoxi River and adjacent to Taihu Lake in the north. The amount of water transferred from the lake is an important part of the available water resources in our city. In 2002, the amount of water diverted from the lake reached 3.479 billion cubic meters, with more than 763 million cubic meters entering the lake and 5.25438 billion cubic meters leaving Jiaxing and Wujiang in Jiangsu Province.

Third, water supply and use.

Water Supply The total water supply of Huzhou in 2002 was 654.38+804 million cubic meters. Among them, the surface water supply is 65.438+74.8 million cubic meters, accounting for 96.9% of the total water supply; The water supply of shallow groundwater source is 30 million cubic meters, accounting for1.7% of the total water supply; Other water sources supply 26 million cubic meters of water, accounting for 1.4% of the total water supply.

In the surface water supply, the water supply of water storage project is 65.438+0.76 billion cubic meters, the water supply of water diversion project is 65.438+0.65438+0.00 billion cubic meters, and the water supply of water lifting project is 65.438+0.462 billion cubic meters.

Water consumption In 2002, the total water consumption in Huzhou was 65.438+0.804 billion cubic meters, a decrease of 65.438+0.7 billion cubic meters compared with the previous year. Among them, urban domestic water consumption is 56 million cubic meters, accounting for 3. 1% of the total water consumption, an increase of14.9% over the previous year; Rural domestic water consumption is 59 million cubic meters, accounting for 3.3% of the total water consumption, down 5.4% from the previous year; The water consumption of state-owned and industrial enterprises above designated size was 230 million cubic meters, accounting for 12.7% of the total water consumption, down 4.7% from the previous year; The industrial water consumption below the scale10.43 billion cubic meters, accounting for 7.9% of the total water consumption, 8.0% less than the previous year; The irrigation water consumption of farmland was 1, 654,38+0.29 billion cubic meters, accounting for 62.6% of the total water consumption, which was 2.0% lower than the previous year. The water consumption of forestry and fishery is1870,000 cubic meters, accounting for 10.4% of the total water consumption, increasing by 16.0% over the previous year.

The water consumption of Huzhou City, Deqing County, Changxing County and Anji County in 2002 was 7.97 million cubic meters, 2.95 million cubic meters, 4.75 million cubic meters and 237 million cubic meters respectively, of which the water consumption of Huzhou central city was 88 million cubic meters.

Water consumption In 2002, the total water consumption of all industries in the city was 998 million cubic meters, with an average water consumption rate of 55.3%. Among them, the water consumption of agriculture, forestry and fishery is 849 million cubic meters, the industrial water consumption is 0.8/kloc-0.0 billion cubic meters, and the urban and rural domestic water consumption is 68 million cubic meters.