Management And Adjustment Of Beijing Water Supply In The South-to North Water Benefited Area

The prominent contradiction between limited supply of water resources and the increasing population makes the importance of sustainable supply of water resources gradually recognized. Beijing, as the capital of our country, is not only our country’s political center, but also our country’s economic and cultural center. The multiple cities’ function properties make it be one of the world’s megacities with concentrated population. However, the natural resources of Beijing are not adequate to support such a big population. Firstly, the population of Beijing is increasing with the rapid economy development. Secondly, Beijing is located in the north area in our country, and has a typical warm temperate semi-humid continental monsoon climate with low annual rainfall, and face the shortage of water resources. Therefore, it has become an urgent issue that how to ease the sharp contradiction between limited water resources and increasing population of Beijing.The South-to-North Water Transfer Project is a grand project, which is expected to alleviate the contradictions to some extent that the water resources are distributed uneven in time and space in our country. The Middle Route and Eastern Route Projects are involved in transferring the water resources of Yangtze River to the water shortage cites along the routes to resolve their water supply difficulties. The Middle Rout Project plays a critical role in easing the contradiction between supply and demand of water resources in Beijing. However, the transfer of water resource has various impacts on Beijing such as the quantity, quality and cost of water resources, and so on, which can bring certain influence to Beijing’s municipal water supply system. The quality difference between the introduced water resources and the local water resources will bring a huge challenge to the existing water treatment system and water supply piping system of Beijing. Therefore, how to scientifically manage and adjust the existing water supply system after the water resources are introduced has practical significance for the security of water supply and the sustainable economy and social development.Based on the investigation of introduced water resources from South-to-North Water Transfer Project, and the supply and utilization of water resources in Beijing, the research focuses on the management and adjustment of water supply system of Beijing regarding to the multiple supply of water resources for Beijing. The main research contents and achievements are as follows:1. Based on the investigation of various types of water resources in Beijing, we found that the total amount of surface water resources of Beijing is in the range of 676 to 1795 million m3 and the groundwater resource is in the range of 1.508 to 2.155 billion m3. Thus the total amount of water resources is in the range of 2.184 and 3.950 billion m3. The total amount of water resources in the normal year are basically fluctuating around 2.5 billion m3, the change of which is significantly influenced by the atmospheric precipitation.2. The situation of water resources supply in Beijing was analyzed. Also, the requirement of water resources to meet the economic and social development in Beijing was investigated. The water consumed in Beijing can be divided into domestic water, industrial water, agricultural water and environmental water. In recent years, there is some certain changes in the water consumption of Beijing with a decreased water consumption by the first and the second industry and the increased consumption of agricultural water and environmental water. The total annual water consumption of Beijing ranges from 3.60 to 3.96 billion m3 with a slight fluctuation around 3.5 billion m3 overall. The pressure of water demand in Beijing is still huge.In recent years, the consumption of industrial water basically maintains at around 500 million m3. The consumption of domestic water increases from 1.56 billion m3 in 2011 to 1.86 billion m3 in 2015 with an annual average growth rate of 4.8 %. The consumption of environmental water increases from 0.45 billion m3 in 2011 to 0.83 billion m3 in 2015 with an annual average growth rate of 21 %. In contrast, the consumption of agricultural water falls sharply by annual average rate of 7.8% from 1.09 billion m3 in 2011 to 0.75 billion m3 in 2015. The consumption change of water resources for particular purpose is closely related to economic development plans and policies of Beijing. The stable consumption of industrial water indicates that the relocation strategy of heavy industrial has begun to work. The reduced consumption of agricultural water demonstrates that the urbanization process has compressed the space of agricultural development. Meanwhile, the urbanization results in the increasing population of the city, hence the consumption of domestic water and the urban environment water is increased.3. The study showed that the supply of water resources in Beijing is diversified with a limited total amount. Based on the situation of short water resources and contradiction between supply and demand of water resources in Beijing, it has formed a basic pattern of water supply system comprising local surface water, groundwater, reclaimed water, emergency water and transferring water. According to the change of water resources in Beijing, three annual water supply schemes comprising 4 billion m3, 4.8 billion m3 and 5.4 billion m3, respectively, were proposed. It is considered that the limit amount of water supply for Beijing will reach to 5.4 billion m3, according to social and economic development demand for water resources in Beijing.4. The influence factors on carrying capacity of water resources were investigated, and the model construction of current carrying capacity of water resources in Beijing was discussed.The water resources carrying capacity of Beijing was analyzed via the model construction of water resources carrying capacity. The study showed that the water resources carrying capacity displayed a decline trend yearly, with a declining rate of 5% basically from 2005 to 2008. Since 2008, the decline trend of water resources carrying capacity has slowed down with a rate of 1.5% to 3%. The water resources carrying capacity was improved by 2013, indicating that protective measures have had a positive effect on the water resources protection since the successful Olympic, whereas the increase of the water resources carrying capacity in 2013 has a close relationship with the large rainfall in 2012.The overload of water resources carrying capacity was analyzed. The results showed that the main reason for the overload of water resources carrying capacity was caused by the increasing contradiction between supply and demand of water resources, imperfect water property system, and the poor allocation of resources due to improper management of water resources, as well as water pollution that exacerbates the shortage of water resources. The water use efficiency cannot be reflected by the water price also makes a contribution to the overload of water resources carrying capacity. The transferring water enriches the water supply resources of Beijing and improves the water supply ability, achieves local water conservation effectively.5. The study on the effects of the South-to-North Water Transfer Project on the water quality was conducted, and the water quality difference between the indroduced water during the first phase and the local water was also discussed.On the basis of the analysis and comparison of the water quality difference between the introduced water from the project and the local water, we found that the main difference between introduced water and local water is in five factors including sulfate, chloride, total hardness, electrical conductivity and nitrate nitrogen, and the former is higher than the latter. The difference leads to the change of the water treatment process and technology when the water is introduced. The sharp increase of sulfate and chloride ion and the decrease of water alkalinity will result in the enhanced corrosion of water and the acid-base imbalance of water supply network. Hence, the anticorrosion construction for the water supply pipe network in Beijing should be strengthened.The water quality and amount response model was established based on the actual water quality difference between the water introduced from the project and the local water, then the mixture of the water of the project and the local water would be effectively combined to ensure the effective and safe use of the water supply and water supply network.It is considered that the quality of raw water introduced from the project has an uncertainty, because it may suffer from the pollution along the 1200 kilometers of open channel water transport, where there are a large number of villages and bridges. More attentions needed to be paid to algae removal in the protection of water quality. The total nitrogen of raw water in Danjiangkou River is high, and the conversion of organic nitrogen to inorganic nitrogen appears during the long distance transfer of water, which is a potential problem that may be faced by the water treatment process of Beijing. Adequate emergency measures should be taken to prevent the occurrence of sudden water pollution incidents with regard to the open channel water of long distance. Therefore, the potential destruction of the chemical stability of water distribution network should be paid much attention after water switch; the water quality must be adjusted for the introduced water of the project.6. The adjustment and optimization of the water treatment process of Beijing was investigated when the water resources were introduced from the project. Based on the comparison of the advantages and disadvantages of different treatment processes we found that the mechanical agitation settling pond with good treatment effect, low cost, strong adaptability is the first choice in the conventional treatment process. The ozone and biological activated carbon adsorption process can further enhance the safety of conventional process and effectively remove organic matter and microorganisms in water. It is suggested that the advanced ozone and biological activated carbon adsorption process should be introduced for the original conventional treatment process due to the uncertainty of the water quality introduced from the project. The turbidity of effluent can be improved significantly by using ultrafiltration membrane technology, which can be generally controlled below 0.1NTU keeping the water quality stable. Meanwhile, the ultrafiltration membrane technology has a significant control effect of the Giardia and Cryptosporidium, and can effectively remove cryptosporidium, giardia and enterococcus. In view of the fact that Beijing has become an international metropolis with the improvement of people’s living level, the higher water supply safety and quality are required, thus the advanced water treatment process needs to be implemented for the introduced water from project. The ozone activated carbon adsorption technology have a significant improvement effect on such indicators as water color, water smell, etc. Based on the above research, the turbidity of effluent can be controlled at relative low level via ultrafiltration membrane technology and ozone activated carbon adsorption technology.Based on the quality characteristic of the water from the project and the practical conducted experience of the existing water plants, as well as the multiple water resources and high-risk of water resources of Beijing, the optimization procedure of the water treatment process comprising the pretreatment of additive peroxidation or powder activated carbon in an emergency state, conventional treatment of mechanical acceleration sloping-plate clarifying tank, Air-Water Backwashing Filter, protonation biological activated carbon adsorption tank, ultrafiltration membrane process, was proposed.7. Based on the analysis of the properties of water price right, water scarcity, and water nature, the concepts of full cost pricing method, income capitalization pricing and market pricing method have been introduced into the study of the specific impacts of the water from the project on the price of the water supply in Beijing. It is considered that there is a significant difference in price of water industry with a slightly weakened standard for collection of water resource fee. The increasing magnitude and speed of the water price cannot completely demonstrate the contradiction between supply and demand of water, especially in the summer, when there is a relatively large amount of water resources consumption. The water resource has the considerable effect on the economy and social development of Beijing. At present, the current price of the water supply has not yet effectively demonstrated the connotation of water value.The formation model of water price was constructed to investigate the factors that influence the price of water supply of Beijing and the formation mechanism of the water price under multiple water resources condition when the water resource is introduced from the South-to-North Water Transfer Project. Additionally, the medium scheme under normal development speed and the higher plan under the rapid development speed were proposed respectively based on the forecast of the economy and social development level in Beijing. Meanwhile, the schemes for common water consumption level and lower water consumption level were proposed according to the development plan of Beijing. The formation models of water price for four kinds of water demand plans were formed after combination of abovementiond schemes. Based on present data, the component of water price was calculated. Based on the analysis of the available water resources, water shortage situation and the quantity of water supply, the full calculation of cost of the local water supply is realized considering two-part water price when the water was introduced from the project, then the integrated water price calculation was carried out. It was considered that the cost of water will increase in some industries but the comprehensive water price will not beyond the residents’ affordable ability.8. The study showed that water from the project can relieve the pressure of supply and requirement of water resources in some extent in Beijing, but can’t fundamentally solve all the problems regarding to water supply in Beijing. It is necessary for Beijing to strengthen the sustainable utilization of water resources. The government, market tools and social forces should be combined in a comprehensive way to improve relevant laws, regulations, and policies, so as to realize the formation of perfect water price mechanism, optimize the property rights system, innovate market regulating mechanism, and accelerate the construction of water resources market system, then to encourage social forces to actively participate in the sustainable utilization of water resources.