Li Dong
(Yellow River Conservancy Commission Hydrology Bureau Zhengzhou, Henan 450004)
Abstract: The internationally recognized degree of water resources utilization of the warning line is 40%, is not to consider the treatment and utilization of wastewater as well as the "flooding resources" under the premise of the establishment of the standard; at present, China's water resources development and utilization degree of warning line is 40%.
Abstract: The internationally recognized warning line for the degree of water resources utilization is 40%, which is the standard set up without considering the treatment and utilization of wastewater and "flood resource utilization"; at present, the degree of water resources development and utilization in our country is close to 25% on average, but the difference between the north and the south is very large and unbalanced, and the degree of water resources utilization of the northern rivers in the long term is as high as 80%, or even higher; along with the substantial improvement of China's degree of treatment of wastewater, the construction of water conservancy projects and the regularization of "flood resource utilization With the substantial increase in the degree of wastewater treatment in China, the construction of water conservancy projects and the "flood resource utilization" of the normalization, combined with the characteristics of China and the actual situation, after analysis of China's water resources development and utilization of the degree of warning line can be appropriately raised, the northern part of the country is set as high as 60%, and the southern part of the country can be maintained at 40%.
Keywords: degree of water resources development and utilization (rate) warning line medium water use flood (rain) water use
1. The concept of water resources development and utilization
1.1 Definition of water resources development and utilization
The main indicator of the degree of water resources utilization is "water resources development and utilization rate ".
The degree of water resources development and utilization, i.e. water resources development and utilization rate, refers to the proportion of water consumption in a basin or region to the total water resources, and is the degree of water consumption in water resources utilization.
Usually, from the point of view of water resources planning and utilization, water resources development and utilization rate refers to the water supply capacity, i.e., the ratio of water supply available when the guarantee rate is 75% to the total water resources on average over the years, and it is an indicator characterizing the degree of water resources availability.
From the point of view of statistical analysis and calculation of water resources utilization, in addition to the actual consumption of water, can also be used to supply water to the total water resources, reflecting the water resources are consumed that is, the degree of water supply and utilization.
Water resources development and utilization can be divided into river runoff (referred to as surface water) water resources development and utilization and groundwater resources development and utilization, generally to the river as a unit of only surface water resources development and utilization of statistics, watersheds as a unit of comprehensive statistics, or separate statistics, but do not point out in particular (such as the integrated utilization rate), but also only refers to the development and utilization of surface water resources; for example, the development and utilization of a river is the development and utilization of the river. For example, the development and utilization of a river means the development and utilization of surface water resources of the river.
Because the river water is not static, and there are water year, dry year and flat water year, so in the calculation of the actual river water resources development and utilization of the year, with the change of water and different. Of course, there are also abundant water and dry periods in a year, abundant water that is the flood season water reservoirs storage after the dry season use.
September 11, 1987, the State Council General Office forwarded the State Planning Commission and the Ministry of Water and Power "on the Yellow River water supply allocation program report notice". The allocation plan of the Yellow River water supply capacity is based on the runoff of the Yellow River which is 37 billion m3.The water supply capacity of the Yellow River is the amount of water available outside the river channel after deducting the amount of sand transport and ecological water.
For example, in 1997, when the Yellow River was cut off from the sea, the runoff flow of Lijin was only 1.86 billion m3, and the utilization rate of surface water resources was as high as 80% that year, of course, here refers to the degree of consumption, that is to say, 80% of the water was consumed, then the degree of utilization of that year was higher, because some of the utilization of the volume of the return to the river channel was not consumed.
1.2 internationally recognized degree of utilization of water resources warning line
In 2002, the new revision of the "Chinese people's **** and the State Water Law", the Chinese National People's Congress judicial interpretation of the authoritative put forward: the international generally recognized on the exploitation of a river can not exceed the amount of water resources of 40% of the warning line.
The value is the average of a wide range of long time. For different years as well as the year should not be a fixed data, at the same time has two obvious characteristics: the time period of each region is inconsistent; with the economic development of water conservancy engineering development, scientific and technological development, rainwater utilization blossomed with large-scale engineering flooding centralized use of sewage treatment and water use and other means of application, it should be said that the warning line of the data is not static, with the socio-economic development At the same time, China is a serious water shortage and frequent droughts and floods can not be completely copy the so-called international warning line.
2. China's water resources development and utilization of the status quo
China's water resources development and utilization of the degree of close to 25%, in terms of the whole country, is not exactly the same, showing a "high north and low south", the south, especially in the southwest, rich in water resources but the amount of use is small, the use of the degree of low, and the northern part of the arid areas of the north-west and north China, especially the degree of utilization is high. North China is utilized to a high degree.
2.1 Higher utilization rate of water resources in the north
The major rivers in the north have exceeded 50%, of which the Haihe River Basin and the Black River Basin have exceeded 90% in some years. The water resources utilization rate of the Yellow River, Hai River, Liao River and Huai River generally exceeds the international warning line, of which the Hai River and Huai River divert about 10 billion m3 of water from the Yellow River every year, and some inland rivers exceed 100%.
Water Resources Bulletin of Gansu Province in 2007: The degree of water resources development and utilization, i.e., the ratio of gross water consumption to the amount of water resources (the sum of self-produced surface water and unduplicated groundwater). It is 45.8% for the whole province; 100.2% for the inland river basin; 37.8% for the Yellow River basin; and 4.1% for the Yangtze River basin.
Huai River Water Resources Bulletin: In 2008, the utilization rate of surface water resources in the Huaihe River Basin was 49.9% (the utilization rate of surface water resources refers to the percentage of surface water supply to the amount of surface water resources), the utilization rate of surface water resources in the Shandong Peninsula was 19.9%, and the utilization rate of surface water resources in the Huaihe River Area was 45.6%.
In 2008, the natural runoff of the Haihe River Basin was 12.693 billion m3, the surface water supply was 12.310 billion m3, and after deducting 4.325 billion m3 of inter-basin water transfer, the local surface water supply was 7.985 billion m3, and the utilization rate of surface water resources was 62.9%
2.2 The utilization rate of water resources in the south is generally low
According to the China Water Resources Bulletin, in 2008, the amount of water flowing into China from outside the country was 23.3 billion m3; the amount of water flowing out of the country from within the country was 605.7 billion m3, and the amount of water flowing into the rivers at the international borders was 64.7 billion m3; and the amount of water entering the sea in the whole country was 1,610.1 billion m3.
From the perspective of 2008, each year, more than 2.2 trillion m3 of water resources of the runoff of rivers in our country were not utilized and went out to the sea. into the sea out of the country.
The development and utilization of water resources in the south is low, only 18% in the Yangtze River Basin.
According to the Yunnan Water Resources Bulletin, the province's water resources development and utilization rate (water resources development and utilization rate is the ratio of the amount of water supplied out of the river to the average amount of water resources for many years) was 6.9% in 2008.
In 2007, the Pearl River Basin piece of water resources development and utilization rate of 20.2%, but individual areas of economically developed regions also exceeded 80%, of which the economically developed Pearl River Delta has the highest water resources development and utilization rate of 83.1%.
2.3 China's water resources development and utilization rate of regional differences
China's water resources development and utilization rate of the high north and low south and rainfall zones and human activities are closely related.
Because of the influence of population density, economic structure, crop composition, level of water conservation, water resources conditions and other factors, the value of water use indicators vary greatly from region to region.
The 1999 China Water Resources Bulletin estimated the surface water control utilization rate (the percentage of water supplied by surface water sources to the surface water resources) for the nine major river basins based on the results of water resources calculations and water supply and use statistics, and taking into account the effects of inter-basin water transfers, water storage variables in reservoirs, and groundwater storage variables, among other factors. The surface water control utilization rate is also the utilization rate of surface water resource development. It is 24% in Songliao River Area (including 52% in Liaohe River Basin), 94% in Haihe River Area, 76% in Yellow River Area, 78% in Huaihe River Area, 15% in Yangtze River Area, 18% in Zhujiang River Area, 14% in Southeast Rivers Area, 2% in Southwest Rivers Area, and 34% in Inland Rivers Area (including 80% in Inland Rivers in Hexi).
In short, China's water resources development and utilization of the degree of regional distribution is uneven, "high in the north and low in the south", with the climate and human activities and changes, high drought years, low water year, with the social development of the total water consumption increases.
3. China's arid water shortage situation determines the inevitable need for a large number of water resources
China is a serious arid water shortage of countries, China's per capita water resources is only 2,300 m3, only 1/4 of the world's average level, ranked 121st in the world, the world's average per capita water resources is one of the poorest countries, is the United Nations recognized as a " water-scarce" countries. water scarcity" countries recognized by the United Nations.
China has drought every year, on average, less than three years a major drought, especially frequent regional drought. It is we attach importance to the construction of water conservancy projects, "water conservancy is the lifeblood of agriculture", water conservancy, in many years of drought still win a bumper agricultural harvest, so that China's grain production year after year record high.
China is a vast country, the climate and other natural conditions vary greatly, southwest, southeast coastal areas due to the monsoon and typhoon, precipitation is relatively abundant, the amount of water resources is relatively rich, but the north, especially in the northwest, especially inland areas of the northwest of the precipitation is scarce, the amount of water resources is scarce, the amount of water resources per capita is only 1/8 of the national average-1/10. In the past, China's drought-prone areas were mainly in the arid and water-scarce northern regions, especially in the northwest. In recent years, while the drought in the traditional northern drought areas has been aggravated, drought in the rainy southern and eastern regions has also occurred, and is even expanding and aggravating.
The 2010 Southwest China Drought affected five provinces in southwest China (Yunnan, Guizhou, Guangxi, Sichuan and Chongqing) and spread to Hunan and other provinces and cities. The impact of the drought has been extended from traditional agriculture to industry, urban, ecological and other areas, agriculture and industry competition for water, urban and rural competition for water, over-exploitation of groundwater and crowded ecological water use phenomenon is becoming more and more serious, in particular, the people and livestock drinking water is seriously difficult to spend a lot of human and material resources.
According to the analysis of meteorological experts, this is the most serious drought suffered by the southwest since the meteorological data. The drought is due to low precipitation, high temperatures, the two causes **** the same role, coupled with a long duration, leading to natural disasters causing serious losses.
4. China's water resources by the ocean monsoon control precipitation spatial and temporal distribution of uneven
To fully understand the water nature of natural renewable resources. In the sun and the role of the Earth's surface heat, the surface of the water is constantly being evaporated into water vapor, into the atmospheric circulation, with the air transport and rise, the intersection of warm and cold air currents, the water vapor is cold and cohesion into droplets, under the action of gravity, in the form of precipitation to the ground, the process of this week after week, known as the water cycle. Under the influence of atmospheric circulation, the ocean and the continental water cycle into one, China's water supply source is mainly monsoon atmospheric precipitation, the southeast monsoon, the southwest monsoon is the formation of China's precipitation is the main source of the Pacific Ocean, the Indian Ocean water vapor transported to China's southwest, southeast of the vast area, especially the southeast monsoon deep into the central and western regions of China, even China's precipitation in Xinjiang, also known as the westerly wind circulation of the Atlantic Ocean water vapor Transportation over. For example, the typhoon is a typical meteorological phenomenon of the sea and land water cycle, the typhoon conveys a large amount of ocean water vapor, a short period of time to bring a large amount of precipitation, the formation of torrential rains, to the land caused by the disaster.
River water is not static, affected by precipitation, there are abundant, dry points. And China's vast area, east and west, north and south of the climate difference, at the same time by the circulation and monsoon influence, precipitation year to year are very big changes, resulting in China's water resources from the spatial distribution of uneven, time on the inter-annual abundance of the difference between the years, the year is more concentrated in the flood season.
From the perspective of the year, most of China's precipitation is mainly concentrated in the flood season, its precipitation accounted for more than 60% of the annual precipitation, by the flood season and winter precipitation statistics, excluding the snowy mountains and glaciers melt water (snowfall and rainfall and replenishment), China's water resources each year renewed from the ocean monsoon atmospheric precipitation of more than 90%.
Because of the flood season in order to prevent flooding, every year China's more than 2 trillion m3 of river runoff water resources have not been utilized into the sea or out of the country.
5. The impact of human activities on the establishment of warning line standards in China
5.1 Large and medium-sized reservoirs to store flood water
Only through the establishment of high dams and large reservoirs to have more water storage capacity, it is possible to realize the "flood water resourceization". China's construction of Xiaolangdi, especially the Three Gorges Water Conservancy Hub Project has the experience and ability to build mega-reservoirs, with the ability to regulate flooding large reservoirs, high dams and large systems backbone project as a foundation, relying on key technologies for support.
Flood resourceization is to intercept the flood water into the sea to stay on land for use, increase hydropower generation, as social water supply and ecological environment water. In the Yellow River Basin used to transfer water and sand, that is, the use of flood water through the reservoir scheduling water and sand in the reservoir area and river sediment discharge into the sea. Storing flood water in large quantities on land is conducive to counteracting the rising trend of the sea.
In many parts of our country has formed a traditional view of the flood is a disaster, to be discharged as soon as possible, into the sea for peace; not the flood as a resource, "the benefits of combining with the elimination of hazards," is also said to be the use of non-flooding resources and prevention of large floods. Floods have brought great disasters to mankind, at the same time, floods can also be utilized, that is, with the dual characteristics of water hazards and water conservancy.
The proposal of flood resources is intended to flood prevention and mitigation, eliminating hazards and benefit effectively combined to achieve "to give the flood out of the way, so that part of the flood water for my use" water management strategy, and further promote the harmonious development of people and water.
Frankly speaking, the flood is not completely controlled, but also can not be completely eradicated, although China has established an effective flood control system in the big rivers, flood problems will still be China's long-term heart of the problem; since we can not control the flood, then we can use engineering measures and "management of floods," including "Flood resource utilization" as the main content of the measures to comprehensively manage floods. Flood utilization and flood resource utilization in China's relatively scarce water resources is particularly important.
China's reservoir regulation capacity is limited, such as the Yellow River only Longyangxia for multi-year regulation reservoir, and the famous Three Gorges Reservoir is only seasonal regulation reservoir.
China is vigorously developing water conservancy and hydropower clean energy, the main river has done the planning, it is recommended that the feasibility of the basis of a moderate increase in the height of the dam to increase the reservoir capacity for flood control and flood utilization to increase the effective "public welfare" reservoir capacity. On the one hand, more flood water storage to achieve the purpose of flood control, on the other hand, more power generation to make up for the hydropower due to the dry season brought about by the peak, but also for the social water supply and cross-basin water supply to provide the possibility. Such as the Yangtze River Basin to the Three Gorges Reservoir above can be divided into three levels, in the front of the dry tributaries of the reservoir as a first-class, can be stored in the flood season, a large number of intermediate reservoirs in order to store floods in mid- to late August, the Three Gorges Reservoir and the Danjiang River Reservoir can be stored in September floods, so that the formation of the flood season in the mid- to late-stream flood storage to achieve the use of the flood to achieve a greater effectiveness of the gradient.
5.2 water catchment project
Rainwater utilization is to collect, concentrate and store rainwater from natural or artificial rain catchment surface for human use.
Rainwater utilization will make an important contribution to solving the problem of water shortage in the future.
The collection of rainwater for human and animal drinking and agricultural production, China's 2010 drought in the southwest part of the region's water cellar played a big role. Water-scarce Gansu Province to carry out research and promotion of rainwater harvesting and utilization technology, in 2009 has built a total of 2.53 million various water storage cellar, a stable solution to the 2.52 million people's drinking water difficulties, the development of rainwater harvesting and irrigation 4.57 million mu of agriculture, rainwater utilization in the accumulation of a wealth of experience and technology. In the management of soil and water conservation also play a huge role, silt dams and terraces can achieve "water does not go downhill".
The utilization of rainwater is an important measure to solve the problem of water shortage and flood control in cities. Beijing Municipality from 2003 on the development and implementation of "on the strengthening of construction projects within the land of rainwater resources utilization of the Interim Provisions," requiring that all new construction, alteration and expansion of the project should be added to the construction of rainwater utilization project, otherwise the relevant departments will not be accepted.
5.4 Cross-basin water transfer projects
An important feature of China's water resources distribution is that there is a lot of water in the south and little water in the north, and the spatial distribution is very unbalanced. River runoff mainly comes from precipitation, and what affects precipitation in most parts of China is the southeast monsoon from the western Pacific Ocean and the southwest monsoon from the Indian Ocean and the Bay of Bengal.
Trans-basin water transfer project water resources and flood resourceful redistribution is guaranteed.
Comrade Mao Zedong inspected the Yellow River and proposed that "there is much water in the south and little water in the north, so if possible, it is possible to borrow a little."
The South-to-North Water Diversion Master Plan recommended three water transfer routes: the eastern route, the central route and the western route. Through the three water transfer lines to the Yangtze River, the Yellow River, Huaihe River and the Haihe River, the four major rivers, constituting the "four horizontal and three vertical" as the main body of the overall layout, in order to facilitate the realization of China's water resources in the north and south, east and west of each other, the rational allocation pattern. Planning envisioned three water transfer lines of multi-year average annual total scale of 44.8 billion m3, of which 14.8 billion m3 of the eastern line, 13 billion m3 in the middle line.
The main water supply object of the South-to-North Water Diversion Project in the near future to determine for the city, can be gradually replaced by crowded agricultural and ecological water, limiting the over-exploitation of groundwater, the use of water years to increase the north of the transfer of water to restore and improve the groundwater environment, increasing agricultural, ecological and water. water consumption.
According to the results of the recent planning, in 2020, the country will utilize 11.8 billion m3 of water from the inter-basin water transfer project to support the management of over-exploitation of groundwater and compress the corresponding amount of groundwater extraction.
5.5 Wastewater Treatment and Utilization
The internationally recognized warning line for the utilization of water resources does not take into account the wastewater treatment and utilization of the premise of the establishment of the standard.
Internationally, about 70% of the water used by society under normal circumstances ends up as wastewater, which is re-discharged into the river system. Therefore, if the utilization rate of water resources is 40%, then about 28% of the sewage will be discharged into the river, and when combined with the original 60% of unused river water, the entire river will have almost half of the sewage added to it, which will cause more serious pollution to the river. The main pollutants in the social water here come from industrial and mining enterprises and urban life.
International general situation is not necessarily suitable for the specific situation in China, China's northern region of water resources development and utilization of up to 80%, after more than two decades of unremitting efforts, the river ecology has gradually been restored, in particular, sewage treatment and reuse or up to the standard discharge or zero discharge, so that the so-called internationally recognized degree of water resources utilization of the warning line has long been or has been unsuitable for the reality of the situation, it is suggested that China's degree of water resources development and utilization of the warning line can be set to 50% more appropriate.
The reuse of sewage treatment refers to the amount of sewage reused after centralized treatment in urban sewage treatment plants, excluding the reuse of wastewater treatment within industrial enterprises. Water, also known as reclaimed water and reuse water, refers to the non-potable water that can be used within a certain range after urban sewage and industrial wastewater are purified and treated and the water quality is improved to meet the national standard for urban wastewater reuse. If these wastewater can be converted into water through treatment will undoubtedly be a huge resource. Improve the sewage treatment rate, increase the amount of sewage utilization, sewage resource utilization into the stage of carrying out a large number of uses.
According to China's water resources bulletin, in 2008, the country's total water consumption of 591 billion m3, the total water consumption of 311 billion m3, the integrated water consumption rate (consumption as a percentage of water consumption) of 53%, in 2008, the country's total wastewater discharges of 75.8 billion tons; wastewater discharges refers to the water discharged by water users of industry, the tertiary industry, and urban residential life, but does not include Thermal power DC cooling water discharge and mine pit drainage.
Improve other water sources such as sewage resource utilization, seawater desalination utilization, there will be more than 100 billion m3 potential in the future.
6. Conclusion
China's water resources development and utilization is now close to 25%, but there are great differences between basins.
Internationally recognized as a basin or the country's degree of water resources utilization of the warning line is 40%, is not to take into account the premise of wastewater treatment and utilization of the establishment of the standard, and China's northern rivers for a long period of time the degree of water resources utilization more than the warning line, some years as high as 80%, or even higher.
With the substantial increase in the degree of wastewater treatment in China, water discharge or zero discharge, rainwater projects and desalination, cross-basin water transfer projects, as well as with the completion of water conservancy projects, high dams and reservoirs backbone project, "flood resource utilization" of the normalization of the combination of China's characteristics and the actual situation in our country. The degree of water resources development and utilization of the warning line can be appropriately raised, the northern part of China to set a high of 60%, the south can also be maintained at 40%.
Trans-basin water transfer and international river development and utilization, reduce runoff into the sea, "flood resources", through the establishment of high dams and large reservoir capacity backbone projects to achieve this purpose, through engineering measures to cope with climate anomalies, "excessive floods", combined with the management of scientific intelligence, before and after the flood season. Scientific intelligence, before and after the flood season, "electricity transfer" is strictly subordinate to the "water transfer", which is conducive to the long-term stability of the river to provide engineering safeguards.
References: slightly.
References: omitted.