Volume 0,Issue 1,2023 Table of Contents
2023(1):1-12.
Abstract:
On the basis of sorting out the correlation between water resource behavior and the goals of carbon peak and carbon neutrality, the action mechanism and the measure problems of water resources behaviors (WRB) on the carbon peak and carbon neutrality goals were described. From the four dimensions of water resource development, allocation, utilization and protection, the CO2 emission equivalent analysis (CEEA) method of WRBs was proposed, and the CO2 emission equivalent analysis function table (FT-CEEA) was given, including the calculation formula of carbon dioxide emission equivalent (CEE) of 16 kinds of WRBs. The purpose is to provide a reference "ruler" for accounting CO2 emission in the water sector. Then, taking Henan Province as an example, the application research of CEEA method was carried out. The results showed that: (1) The total CEE of WRBs in Henan Province in 2020 was 28.886 1 million tons, and water resource utilization behavior (WRUB) was the main contributor; (2) CO2 emission effect is generated by water resource exploitation behavior (WRDB), water resource allocation behavior (WRAB) and water resource utilization behavior (WRUB), and CO2 absorption effect is generated by water resource conservation behavior (WRPB). The CEE of the four types of WRBs was 11.88 million tons, 5.65 million tons, 14.48 million tons, and ?3.12 million tons, respectively. The research results can provide reference for the follow-up research on CO2 emission equivalent accounting in the field of water resources.
On the basis of sorting out the correlation between water resource behavior and the goals of carbon peak and carbon neutrality, the action mechanism and the measure problems of water resources behaviors (WRB) on the carbon peak and carbon neutrality goals were described. From the four dimensions of water resource development, allocation, utilization and protection, the CO2 emission equivalent analysis (CEEA) method of WRBs was proposed, and the CO2 emission equivalent analysis function table (FT-CEEA) was given, including the calculation formula of carbon dioxide emission equivalent (CEE) of 16 kinds of WRBs. The purpose is to provide a reference "ruler" for accounting CO2 emission in the water sector. Then, taking Henan Province as an example, the application research of CEEA method was carried out. The results showed that: (1) The total CEE of WRBs in Henan Province in 2020 was 28.886 1 million tons, and water resource utilization behavior (WRUB) was the main contributor; (2) CO2 emission effect is generated by water resource exploitation behavior (WRDB), water resource allocation behavior (WRAB) and water resource utilization behavior (WRUB), and CO2 absorption effect is generated by water resource conservation behavior (WRPB). The CEE of the four types of WRBs was 11.88 million tons, 5.65 million tons, 14.48 million tons, and ?3.12 million tons, respectively. The research results can provide reference for the follow-up research on CO2 emission equivalent accounting in the field of water resources.
2023(1):13-21.
Abstract:
The analysis of the complex relationship between water-energy-carbon is crucial to promoting the green transformation of economy and society. Meanwhile, it is also a major requirement for water security, energy security, ecological and environmental security, and the building of a community with a shared future for mankind. At present, China's water, energy, and carbon emissions are interdependent and mutually restricted, and the contradictions among them are becoming more and more serious, hindering sustainable social and economic development. Besides, in the context of the “carbon peaking and carbon neutrality” target, for many energy consumption fields, it means not only improving the proportion of clean energy from the supply side but also changing the way of energy use and improving energy efficiency from the user side. However, whether the energy transformation will lead to an increase in water demand needs further study. China is one of the world's largest users of water resources, energy consumption, and greenhouse gas emissions. Clarifying the complex relationship between water resources, energy and carbon emissions will help ensure China's high-quality development, ecological progress, and comprehensive ecological and environmental improvement as scheduled. Based on this, the conceptual connotation of the complex relationship of water-energy-carbon is systematically sorted out and it is believed that its essence is the relationship between water resources, energy, and carbon emissions in the entire product life cycle process. Reviewing the recent progress of complex relationships, the evaluation methods can be summarized into the evaluation based on the perspective of coupling and association, perspective of overall synergy, the outlook of risk and resilience, and the comprehensive perspective of land use. In addition, it is suggested that the following four frontier topics should be focused on in the future: Research on the optimization of territorial space based on water-energy-carbon carrying capacity, and on the premise of not exceeding the carrying capacity of resources, effectively build a territorial spatial pattern system conducive to supporting the implementation of the "carbon peaking and carbon neutrality" strategy; Clarify the decoupling effect and driving relationship between resource consumption and economic growth, and promote the realization of truly SDGs (Sustainable Development Goals); Establish an appropriate evolution model for the certainty and uncertainty of the water-energy-carbon complex system, and realize the dynamic simulation and evaluation of the complex system from multiple perspectives and scales; Realize “negative emissions” through water-energy-carbon engineering measures, including ocean fertilization, green energy production, enhanced rock weathering, increased soil carbon sequestration, coastal wetland restoration, etc. This research aims to achieve the coordinated and sustainable development of the water-energy-carbon system through systematic governance and scientific management and control.
The analysis of the complex relationship between water-energy-carbon is crucial to promoting the green transformation of economy and society. Meanwhile, it is also a major requirement for water security, energy security, ecological and environmental security, and the building of a community with a shared future for mankind. At present, China's water, energy, and carbon emissions are interdependent and mutually restricted, and the contradictions among them are becoming more and more serious, hindering sustainable social and economic development. Besides, in the context of the “carbon peaking and carbon neutrality” target, for many energy consumption fields, it means not only improving the proportion of clean energy from the supply side but also changing the way of energy use and improving energy efficiency from the user side. However, whether the energy transformation will lead to an increase in water demand needs further study. China is one of the world's largest users of water resources, energy consumption, and greenhouse gas emissions. Clarifying the complex relationship between water resources, energy and carbon emissions will help ensure China's high-quality development, ecological progress, and comprehensive ecological and environmental improvement as scheduled. Based on this, the conceptual connotation of the complex relationship of water-energy-carbon is systematically sorted out and it is believed that its essence is the relationship between water resources, energy, and carbon emissions in the entire product life cycle process. Reviewing the recent progress of complex relationships, the evaluation methods can be summarized into the evaluation based on the perspective of coupling and association, perspective of overall synergy, the outlook of risk and resilience, and the comprehensive perspective of land use. In addition, it is suggested that the following four frontier topics should be focused on in the future: Research on the optimization of territorial space based on water-energy-carbon carrying capacity, and on the premise of not exceeding the carrying capacity of resources, effectively build a territorial spatial pattern system conducive to supporting the implementation of the "carbon peaking and carbon neutrality" strategy; Clarify the decoupling effect and driving relationship between resource consumption and economic growth, and promote the realization of truly SDGs (Sustainable Development Goals); Establish an appropriate evolution model for the certainty and uncertainty of the water-energy-carbon complex system, and realize the dynamic simulation and evaluation of the complex system from multiple perspectives and scales; Realize “negative emissions” through water-energy-carbon engineering measures, including ocean fertilization, green energy production, enhanced rock weathering, increased soil carbon sequestration, coastal wetland restoration, etc. This research aims to achieve the coordinated and sustainable development of the water-energy-carbon system through systematic governance and scientific management and control.
2023(1):22-28,38.
Abstract:
In the new stage, the implementation of the "double carbon" strategy was put forward and integrated into the overall layout of ecological civilization construction and the overall situation of economic and social development by China government from the height of the harmonious coexistence of man and nature to plan and develop, which would have a profound impact on China's economic and social development and ecological civilization construction. The strategic goal of "double carbon" was to strive to reach the peak of China's total carbon emissions by 2030 and to achieve carbon neutrality by 2060. The core task was to increase carbon sinks, to reduce carbon emissions, and to achieve carbon control and carbon reduction goals. Water resources was a basic natural resource, strategic economic resource and controlling ecological factor. Water resources was closely related to carbon control and carbon reduction. The water-carbon cycle was a biophysical and ecological process that was closely coupled in the material cycle and energy exchange of the earth's land surface system. As an important input and environmental output of social and economic development, water, energy and carbon were also closely related in the economic and social fields. In the long-term evolution of the earth, the carbon cycle of the earth had formed its inherent laws and characteristics, but the interference of human activities on the carbon cycle since the industrial revolution had made the carbon concentration in the atmosphere beyond the range of natural variability. The change of carbon concentration caused global climate change, further caused the change of water cycle rhythm, and made extreme hydrological events such as drought and flood occur more frequently. In addition to the water-carbon cycle process in nature, water-carbon also had a close relationship in the economic and social system. A wide range of economic and social activities need to consume water and energy, discharge sewage and carbon dioxide. Under the "double carbon" strategy, the adjustment of industrial structure and layout had brought about changes in water demand and brought new challenges to water resources security. At present, the research on water and "double carbon" strategy mainly focused on how to implement the "double carbon" strategy requirements and adaptation measures in the water conservancy industry. There were still few studies on the response of water cycle and the change of water demand situation under the "double carbon" strategy. Based on the research of relevant literature, an in-depth analysis of the impact of the implementation of the " double carbon" strategy on the supply and demand of water resources was made in this paper, as well as the response of water cycle and the change of water demand situation under the "double carbon" strategy, so as to facilitate the formulation of adaptive and supportive measures, which had important theoretical value and practical significance for strengthening the comprehensive management of water-carbon and promoting sustainable development. Studies had shown that water and carbon cycles were closely linked in nature through plant photosynthesis and evapotranspiration, and were closely related to the supply-use-consumption-discharge process of water resources and energy in the economy and society. The implementation of the "double carbon" strategy had a certain impact on both supply and demand of water resources. The supply side was mainly reflected in the spatial and temporal distribution of precipitation and runoff, and the demand side was mainly reflected in the adjustment of industrial structure and layout and the associated water demand changes. In view of the natural cycle change of water-carbon and its impact under the "double carbon" strategy, it should be to further strengthen the research and formulate adaptive measures, and at the same time strengthen the active regulation of water resources and energy supply-use-consumption-discharge process in the economic and social field, so as to realize the harmonious unity of water resources-economic society-ecological environment, and provide support for the realization of the “double carbon” goal and the high-quality development of economy and society.
In the new stage, the implementation of the "double carbon" strategy was put forward and integrated into the overall layout of ecological civilization construction and the overall situation of economic and social development by China government from the height of the harmonious coexistence of man and nature to plan and develop, which would have a profound impact on China's economic and social development and ecological civilization construction. The strategic goal of "double carbon" was to strive to reach the peak of China's total carbon emissions by 2030 and to achieve carbon neutrality by 2060. The core task was to increase carbon sinks, to reduce carbon emissions, and to achieve carbon control and carbon reduction goals. Water resources was a basic natural resource, strategic economic resource and controlling ecological factor. Water resources was closely related to carbon control and carbon reduction. The water-carbon cycle was a biophysical and ecological process that was closely coupled in the material cycle and energy exchange of the earth's land surface system. As an important input and environmental output of social and economic development, water, energy and carbon were also closely related in the economic and social fields. In the long-term evolution of the earth, the carbon cycle of the earth had formed its inherent laws and characteristics, but the interference of human activities on the carbon cycle since the industrial revolution had made the carbon concentration in the atmosphere beyond the range of natural variability. The change of carbon concentration caused global climate change, further caused the change of water cycle rhythm, and made extreme hydrological events such as drought and flood occur more frequently. In addition to the water-carbon cycle process in nature, water-carbon also had a close relationship in the economic and social system. A wide range of economic and social activities need to consume water and energy, discharge sewage and carbon dioxide. Under the "double carbon" strategy, the adjustment of industrial structure and layout had brought about changes in water demand and brought new challenges to water resources security. At present, the research on water and "double carbon" strategy mainly focused on how to implement the "double carbon" strategy requirements and adaptation measures in the water conservancy industry. There were still few studies on the response of water cycle and the change of water demand situation under the "double carbon" strategy. Based on the research of relevant literature, an in-depth analysis of the impact of the implementation of the " double carbon" strategy on the supply and demand of water resources was made in this paper, as well as the response of water cycle and the change of water demand situation under the "double carbon" strategy, so as to facilitate the formulation of adaptive and supportive measures, which had important theoretical value and practical significance for strengthening the comprehensive management of water-carbon and promoting sustainable development. Studies had shown that water and carbon cycles were closely linked in nature through plant photosynthesis and evapotranspiration, and were closely related to the supply-use-consumption-discharge process of water resources and energy in the economy and society. The implementation of the "double carbon" strategy had a certain impact on both supply and demand of water resources. The supply side was mainly reflected in the spatial and temporal distribution of precipitation and runoff, and the demand side was mainly reflected in the adjustment of industrial structure and layout and the associated water demand changes. In view of the natural cycle change of water-carbon and its impact under the "double carbon" strategy, it should be to further strengthen the research and formulate adaptive measures, and at the same time strengthen the active regulation of water resources and energy supply-use-consumption-discharge process in the economic and social field, so as to realize the harmonious unity of water resources-economic society-ecological environment, and provide support for the realization of the “double carbon” goal and the high-quality development of economy and society.
2023(1):29-38.
Abstract:
Inter-basin and long-distance water transfer project is generally across multiple provinces and river basins, and normally has a lot of crossing terrain and river-channel-cross, and its hydrogeological environment is complex. Meanwhile, the water transfer project has a larger relationship with the development of local society, economy, ecology, and so on, which relates to lots of risk factors such as the risk of project operation, various types of buildings, flood, dispatching operation, and public safety emergencies. Every type of risk indicator exists at different levels, ranks, and arrangements, and there are both independence and correlation between different risk factors. Therefore, it is hard to evaluate the comprehensive risk of this kind of water transfer project.Multiple-level structure models of risk integration and technology roadmap of risk comprehensive evaluation were proposed. A risk indicator system and risk level standard were built based on risk identification, and a risk integration method was designed. The steps of the method were as follows: The project was divided into several units. The weights of all risk indicators were confirmed. The comprehensive risk value of each unit was calculated. The risk level of the whole project was calculated based on the risk of all units. Considering the difficulty that different units have different risk factors, a risk indicator weight-correcting method was proposed. And the inter-basin and long-distance water transfer project risk integration software was developed based on the risk integration method that was proposed above.A management area of an inter-basin and long-distance water transfer project was taken as an example to calculate and analyze. The management area was divided into 32 units. All risk indicator weights of every unit were corrected based on the initial weights. The comprehensive risk value of every unit was calculated. The overall risk level of the management area was Ⅱ calculated by the developed risk integration software, and the calculation results of the grey clustering analysis method, fuzzy comprehensive evaluation method, radar chart method, matter-element theory, Bayesian formula method, Nemerow indicator method, and comprehensive indicator method shown high consistency. The number of risk indicators of all units was counted by different risk levels, and the result showed that the quantity relationship of different risk indicators is: Ⅱ>Ⅰ>Ⅲ>Ⅳ, and the number of Ⅱ risk indicators is larger than those of Ⅰ, Ⅲ, Ⅳ. This also verified the rationality of the calculation result.The risk indicator system that was built considered the complexity and diversity of the inter-basin and long-distance water transfer project. The risk level standard that was formulated considered the risk possibility and seriousness. The risk integration method that was proposed firstly divided the project into several units, secondly calculated the comprehensive risk value of each unit, and finally got the overall risk of the project, and it handled the problem that it is difficult to evaluate the overall risk level of the inter-basin and long-distance water transfer project. The actual case analysis showed that the risk levels of a management area calculated by the 7 methods were all II which was reasonable after the analysis.
Inter-basin and long-distance water transfer project is generally across multiple provinces and river basins, and normally has a lot of crossing terrain and river-channel-cross, and its hydrogeological environment is complex. Meanwhile, the water transfer project has a larger relationship with the development of local society, economy, ecology, and so on, which relates to lots of risk factors such as the risk of project operation, various types of buildings, flood, dispatching operation, and public safety emergencies. Every type of risk indicator exists at different levels, ranks, and arrangements, and there are both independence and correlation between different risk factors. Therefore, it is hard to evaluate the comprehensive risk of this kind of water transfer project.Multiple-level structure models of risk integration and technology roadmap of risk comprehensive evaluation were proposed. A risk indicator system and risk level standard were built based on risk identification, and a risk integration method was designed. The steps of the method were as follows: The project was divided into several units. The weights of all risk indicators were confirmed. The comprehensive risk value of each unit was calculated. The risk level of the whole project was calculated based on the risk of all units. Considering the difficulty that different units have different risk factors, a risk indicator weight-correcting method was proposed. And the inter-basin and long-distance water transfer project risk integration software was developed based on the risk integration method that was proposed above.A management area of an inter-basin and long-distance water transfer project was taken as an example to calculate and analyze. The management area was divided into 32 units. All risk indicator weights of every unit were corrected based on the initial weights. The comprehensive risk value of every unit was calculated. The overall risk level of the management area was Ⅱ calculated by the developed risk integration software, and the calculation results of the grey clustering analysis method, fuzzy comprehensive evaluation method, radar chart method, matter-element theory, Bayesian formula method, Nemerow indicator method, and comprehensive indicator method shown high consistency. The number of risk indicators of all units was counted by different risk levels, and the result showed that the quantity relationship of different risk indicators is: Ⅱ>Ⅰ>Ⅲ>Ⅳ, and the number of Ⅱ risk indicators is larger than those of Ⅰ, Ⅲ, Ⅳ. This also verified the rationality of the calculation result.The risk indicator system that was built considered the complexity and diversity of the inter-basin and long-distance water transfer project. The risk level standard that was formulated considered the risk possibility and seriousness. The risk integration method that was proposed firstly divided the project into several units, secondly calculated the comprehensive risk value of each unit, and finally got the overall risk of the project, and it handled the problem that it is difficult to evaluate the overall risk level of the inter-basin and long-distance water transfer project. The actual case analysis showed that the risk levels of a management area calculated by the 7 methods were all II which was reasonable after the analysis.
2023(1):39-47,75.
Abstract:
At present, the problem of the uneven spatial and temporal distribution of water resources in China is still very serious, and the lack of overall allocation capacity of water resources in river basins, the poor water ecological environment caused by water shortage, and the failure to eradicate flood and drought disasters have seriously affected China's economic modernization. The State Council of China proposed to vigorously promote the construction process of 172 major water conservancy projects, accelerate the construction of the national water network system, enhance the ability to allocate water resources across regions, and solve the dilemma faced by China's water resources. The Yinjiang-Jihuai Project is one of the 172 major water conservancy projects, realizing the connection of the Yangtze River and the Huai River, the fuze water receiving area and the area along the project, effectively improving the problem of water scarcity and ecological environment, and providing a strong guarantee for the economic take-off of the region.To identify the basic situation of water resource utilization in the engineering construction area and provide basic evaluation and analysis data for the project construction, 9 counties and districts in the water-receiving area of the henan section of the Yinjiang-Jihuai Project are selected to construct a water resource utilization efficiency index (WREI) system that includes three dimensions of water resources, economy and society, and ecological environment, and uses the evaluation method of "single index quantification-multi-index synthesis-multi-criterion integration" to measure the water resource utilization efficiency, and constructs an obstacle model to identify the constraints on the utilization efficiency of water resources in the water resources area. The agglomeration characteristics of water resource utilization efficiency in various counties and districts were analyzed by the spatial autocorrelation model.The results show that in the past decade, the WREI in the water-receiving area has shown a fluctuating upward trend, and under the background of sustainable development, the water resource utilization efficiency of the water-receiving area has been steadily improved and has reached a "high" level. The WREI of the nine counties has gradually converged from the existence of large spatial differences in 2010. The analysis of the obstacle factors of water resources utilization efficiency can be concluded that factors such as the proportion of ecological water use and the per capita water resources share restrict the improvement of water resource utilization efficiency. There is an obvious positive correlation between the water resource utilization efficiency of the water-receiving area of henan in the Yinjiang-Jihuai Project.The WREI in the southern section of the Yinjiang-Huaihe River showed a fluctuating upward trend, with an average annual growth rate of 3.55%, of which the average annual growth rate of EEI(Ecological Environment Index) was the largest and the average annual growth rate of WRI(Water Resources Index) was the smallest. The proportion of ecological water use and per capita water resources are the main constraints on the improvement of WREI in water areas, and the main obstacles in some counties and districts are indicators such as urbanization rate and water production modulus. There is an obvious positive correlation effect on the water resource utilization efficiency in the water-receiving area, taking county continues to show a low-low agglomeration model, and in 2021, the high-high agglomeration model in Suiyang District will fade, and the high-low agglomeration model in Zhecheng County will show a high-low accumulation model.
At present, the problem of the uneven spatial and temporal distribution of water resources in China is still very serious, and the lack of overall allocation capacity of water resources in river basins, the poor water ecological environment caused by water shortage, and the failure to eradicate flood and drought disasters have seriously affected China's economic modernization. The State Council of China proposed to vigorously promote the construction process of 172 major water conservancy projects, accelerate the construction of the national water network system, enhance the ability to allocate water resources across regions, and solve the dilemma faced by China's water resources. The Yinjiang-Jihuai Project is one of the 172 major water conservancy projects, realizing the connection of the Yangtze River and the Huai River, the fuze water receiving area and the area along the project, effectively improving the problem of water scarcity and ecological environment, and providing a strong guarantee for the economic take-off of the region.To identify the basic situation of water resource utilization in the engineering construction area and provide basic evaluation and analysis data for the project construction, 9 counties and districts in the water-receiving area of the henan section of the Yinjiang-Jihuai Project are selected to construct a water resource utilization efficiency index (WREI) system that includes three dimensions of water resources, economy and society, and ecological environment, and uses the evaluation method of "single index quantification-multi-index synthesis-multi-criterion integration" to measure the water resource utilization efficiency, and constructs an obstacle model to identify the constraints on the utilization efficiency of water resources in the water resources area. The agglomeration characteristics of water resource utilization efficiency in various counties and districts were analyzed by the spatial autocorrelation model.The results show that in the past decade, the WREI in the water-receiving area has shown a fluctuating upward trend, and under the background of sustainable development, the water resource utilization efficiency of the water-receiving area has been steadily improved and has reached a "high" level. The WREI of the nine counties has gradually converged from the existence of large spatial differences in 2010. The analysis of the obstacle factors of water resources utilization efficiency can be concluded that factors such as the proportion of ecological water use and the per capita water resources share restrict the improvement of water resource utilization efficiency. There is an obvious positive correlation between the water resource utilization efficiency of the water-receiving area of henan in the Yinjiang-Jihuai Project.The WREI in the southern section of the Yinjiang-Huaihe River showed a fluctuating upward trend, with an average annual growth rate of 3.55%, of which the average annual growth rate of EEI(Ecological Environment Index) was the largest and the average annual growth rate of WRI(Water Resources Index) was the smallest. The proportion of ecological water use and per capita water resources are the main constraints on the improvement of WREI in water areas, and the main obstacles in some counties and districts are indicators such as urbanization rate and water production modulus. There is an obvious positive correlation effect on the water resource utilization efficiency in the water-receiving area, taking county continues to show a low-low agglomeration model, and in 2021, the high-high agglomeration model in Suiyang District will fade, and the high-low agglomeration model in Zhecheng County will show a high-low accumulation model.
2023(1):48-55.
Abstract:
The South-to-North Water Transfer Project is the world's largest inter-basin water transfer project, and its main purpose is to alleviate the serious shortage of water resources in northern China. The main task is to reasonably determine the amount of water transfer, water transfer process and the scope of water transfer. Since its operation, the project has effectively alleviated the current situation of water shortage in northern China and promoted social and economic development. The accuracy of the water transfer efficiency affects the accuracy of the scheduling scheme, and the water transfer loss is an important index reflecting the water transfer efficiency. However, in the operation of the project, due to internal and external factors, there is a difference between the actual water transmission loss and the designed water transmission loss, so it is important to reasonably determine the water transmission loss to achieve accurate scheduling.The calculation accuracy of water conveyance loss has an important impact on the scheduling and configuration of water transfer projects. The traditional Kostiakov empirical formula is of certain value, which can not fully reflect the dynamic characteristics of the change of water transmission loss along the river when it is applied to the unlined river reaches with large geological changes. To overcome the limitations of the traditional Kostiakov empirical formula, it was improved with the integral method and the generalized reduced gradient method. The Liangji canal section of the eastern route of the South-to-North Water Transfer Project was taken as an example, and the field data from 2013 to 2019 were used to calibrate the parameters in the improved Kostiakov empirical formula. Considering that the Liangji canal section is susceptible to spring irrigation during the operation, the field data from 2019 to 2020 and 2020 to 2021 were used, which was significantly affected by spring irrigation to verify the improved Kostiakov empirical formula. To overcome the limitations of the traditional formula, the average relative error between the calculated results and the measured values before and after the empirical formula showed improvement and it varies greatly. From 2019 to 2020, the average relative error after improvement was reduced from 27.26% of the original formula to 7.9%, and from 11.72% to 6.84% in 2020-2021. The calculation error of Kostiakov's empirical formula method in 2019-2020 was relatively large because the Liangji canal section was greatly affected by spring irrigation and the water level was higher during the scheduling period. The calculation error was generally affected by spring irrigation from 2020 to 2021, and the calculation error was reduced. While the settlement result of the improved Kostiakov empirical formula was relatively stable, overcoming the limitation that the original formula was greatly affected by hydraulic factors in the application process, improving the calculation accuracy of water loss, and ensuring the reliability of the calculation results.The improved method overcomes the limitations of the original formula in the actual application of the water transmission loss as a value per unit length and the application range of the parameters in the original formula is not accurate enough, improves the calculation accuracy of the water transmission loss, and fully reflects the superiority of the dynamic change characteristics of the water transmission loss along the course. Improving the Kostiakov empirical formula improves the accuracy and reliability of calculations before the improvement. For the unlined and large differences in engineering geology of the water transmission line, the improved Kostiakov empirical formula method has good applicability, according to the specific characteristics of the water transmission trunk configuration parameters, can be generalized and applied to other canal sections of the water transfer project, and can further study the water transmission loss under different seasons and different water transfer scenarios of the typical canal section, explore the mechanism and factors of dynamic change of multi-scenario water transport, which is conducive to accurate water transfer and improve the efficiency of the project.
The South-to-North Water Transfer Project is the world's largest inter-basin water transfer project, and its main purpose is to alleviate the serious shortage of water resources in northern China. The main task is to reasonably determine the amount of water transfer, water transfer process and the scope of water transfer. Since its operation, the project has effectively alleviated the current situation of water shortage in northern China and promoted social and economic development. The accuracy of the water transfer efficiency affects the accuracy of the scheduling scheme, and the water transfer loss is an important index reflecting the water transfer efficiency. However, in the operation of the project, due to internal and external factors, there is a difference between the actual water transmission loss and the designed water transmission loss, so it is important to reasonably determine the water transmission loss to achieve accurate scheduling.The calculation accuracy of water conveyance loss has an important impact on the scheduling and configuration of water transfer projects. The traditional Kostiakov empirical formula is of certain value, which can not fully reflect the dynamic characteristics of the change of water transmission loss along the river when it is applied to the unlined river reaches with large geological changes. To overcome the limitations of the traditional Kostiakov empirical formula, it was improved with the integral method and the generalized reduced gradient method. The Liangji canal section of the eastern route of the South-to-North Water Transfer Project was taken as an example, and the field data from 2013 to 2019 were used to calibrate the parameters in the improved Kostiakov empirical formula. Considering that the Liangji canal section is susceptible to spring irrigation during the operation, the field data from 2019 to 2020 and 2020 to 2021 were used, which was significantly affected by spring irrigation to verify the improved Kostiakov empirical formula. To overcome the limitations of the traditional formula, the average relative error between the calculated results and the measured values before and after the empirical formula showed improvement and it varies greatly. From 2019 to 2020, the average relative error after improvement was reduced from 27.26% of the original formula to 7.9%, and from 11.72% to 6.84% in 2020-2021. The calculation error of Kostiakov's empirical formula method in 2019-2020 was relatively large because the Liangji canal section was greatly affected by spring irrigation and the water level was higher during the scheduling period. The calculation error was generally affected by spring irrigation from 2020 to 2021, and the calculation error was reduced. While the settlement result of the improved Kostiakov empirical formula was relatively stable, overcoming the limitation that the original formula was greatly affected by hydraulic factors in the application process, improving the calculation accuracy of water loss, and ensuring the reliability of the calculation results.The improved method overcomes the limitations of the original formula in the actual application of the water transmission loss as a value per unit length and the application range of the parameters in the original formula is not accurate enough, improves the calculation accuracy of the water transmission loss, and fully reflects the superiority of the dynamic change characteristics of the water transmission loss along the course. Improving the Kostiakov empirical formula improves the accuracy and reliability of calculations before the improvement. For the unlined and large differences in engineering geology of the water transmission line, the improved Kostiakov empirical formula method has good applicability, according to the specific characteristics of the water transmission trunk configuration parameters, can be generalized and applied to other canal sections of the water transfer project, and can further study the water transmission loss under different seasons and different water transfer scenarios of the typical canal section, explore the mechanism and factors of dynamic change of multi-scenario water transport, which is conducive to accurate water transfer and improve the efficiency of the project.
2023(1):56-64.
Abstract:
The South-to-North Water Transfer area was one of the serious shortage of water resources in China. To continuously promote the work of water resources conservation and ensure the sustainable economic and social development of the South-to-North Water Transfer area, it is of great significance to track and evaluate the current situation of domestic water use in the water demand area in real-time, analyze the influencing factors and existing problems of domestic water use in all provinces and cities in the water demand area, and further tap the potential of domestic water-saving, to promote the water-saving management in the water demand area and improve the utilization efficiency of water resources in the South-to-North Water Transfer Project.This study was conducted based on a questionnaire survey on residents' water consumption habits and adopted a multiple linear regression method to analyze the current situation and differences in household water consumption in provinces and cities in the eastern middle route of the South-to-North Water Transfer Project, identified the main influencing factors of domestic water consumption, and designed water-saving scenarios to simulate the water-saving potential of households.The results show that :1. There were obvious regional differences in the water consumption habits of residents in the eastern middle route of the South-to-North Water Transfer Project. In some northern provinces, Henan, Shandong, Tianjin, and other provinces, the number of people who use water prudently accounts for 27% to 40%, and the per capita domestic water consumption was relatively low. Anhui Province, Jiangsu Province, and other southern provinces and cities account for more luxury water users, about 26%-35%. From the perspective of water consumption behavior, the bathing link accounts for the largest proportion of 45%, which was also the main link causing the difference in water consumption among provinces and cities, and the main segment causing differences in residential water use between provinces and municipalities. The range of fluctuations in water use for domestic bathing was the largest, and the difference in daily per capita bathing water use was over 30%, which was the main segment causing differences in water use. 2. Through the establishment of a multiple linear regression model to analyze the influencing factors of residents' water-saving awareness, it was found that residents' water consumption was greatly affected by multiple factors, such as age, gender, household resident population, income level, personal water consumption habits, and water use equipment. Residents with a high level of awareness and knowledge of water conservation use less water for domestic purposes. Residents who were aware of their water use and local water prices generated less water in the course of their use. 3. The simulation results of water-saving scenarios showed that under the comprehensive water-saving scenario of improving residents' water-saving awareness, adopting rational utilization of wastewater, and replacing water-saving appliances with class I water efficiency, the daily water consumption per capita in the water receiving area could be reduced by about 12%-29%.
The South-to-North Water Transfer area was one of the serious shortage of water resources in China. To continuously promote the work of water resources conservation and ensure the sustainable economic and social development of the South-to-North Water Transfer area, it is of great significance to track and evaluate the current situation of domestic water use in the water demand area in real-time, analyze the influencing factors and existing problems of domestic water use in all provinces and cities in the water demand area, and further tap the potential of domestic water-saving, to promote the water-saving management in the water demand area and improve the utilization efficiency of water resources in the South-to-North Water Transfer Project.This study was conducted based on a questionnaire survey on residents' water consumption habits and adopted a multiple linear regression method to analyze the current situation and differences in household water consumption in provinces and cities in the eastern middle route of the South-to-North Water Transfer Project, identified the main influencing factors of domestic water consumption, and designed water-saving scenarios to simulate the water-saving potential of households.The results show that :1. There were obvious regional differences in the water consumption habits of residents in the eastern middle route of the South-to-North Water Transfer Project. In some northern provinces, Henan, Shandong, Tianjin, and other provinces, the number of people who use water prudently accounts for 27% to 40%, and the per capita domestic water consumption was relatively low. Anhui Province, Jiangsu Province, and other southern provinces and cities account for more luxury water users, about 26%-35%. From the perspective of water consumption behavior, the bathing link accounts for the largest proportion of 45%, which was also the main link causing the difference in water consumption among provinces and cities, and the main segment causing differences in residential water use between provinces and municipalities. The range of fluctuations in water use for domestic bathing was the largest, and the difference in daily per capita bathing water use was over 30%, which was the main segment causing differences in water use. 2. Through the establishment of a multiple linear regression model to analyze the influencing factors of residents' water-saving awareness, it was found that residents' water consumption was greatly affected by multiple factors, such as age, gender, household resident population, income level, personal water consumption habits, and water use equipment. Residents with a high level of awareness and knowledge of water conservation use less water for domestic purposes. Residents who were aware of their water use and local water prices generated less water in the course of their use. 3. The simulation results of water-saving scenarios showed that under the comprehensive water-saving scenario of improving residents' water-saving awareness, adopting rational utilization of wastewater, and replacing water-saving appliances with class I water efficiency, the daily water consumption per capita in the water receiving area could be reduced by about 12%-29%.
WANG?Weiqiang
,
，HAN?Xiaodong
，GUI?Jianye
,
，SONG?Hongwei
,
，
CHEN?Xi，HUANG?Guanxing
,
，ZHAO?Lun，MU?Haidong
,
2023(1):65-75.
Abstract:
The topographic features and rivers along the middle route of the South-to-North Water Transfer Project are complex and diverse, and the groundwater burial conditions are different. Once the canal water is mixed or exchanged with groundwater, it would constitute a potential hazard of canal water pollution. Therefore, the traceability of side slope seepage outside the embankment of the main canal is of great significance to the safety of the main canal project and water quality. It is important to select representative "characteristic indexes" as few as possible for real-time and fast monitoring in emergencies.To master the hydrochemistry characteristic index system of the main canal, the changes of 99 hydrochemistry indexes and 5 isotope indexes in 12 sections of the main canal of the middle route of the South-to-North Water Transfer from 2020 to 2022 were systematically analyzed. Along the main canal for more than 1 000 km and according to three principles that can be widely used along the main canal (universality), the stability detection of the main canal itself (stability), and obvious difference with the surrounding water body (difference), identified the specific indexes of the main canal, and then evaluated the normal dynamic range of the characteristic indexes, provided technical support for rapid study and judgment of side slope seepage and engineering safety of the main canal of South-to-North Water Transfer. The results showed that there were 10 hydrochemistry indexes in the main canal water, which could meet the "universality". For stability, the eight hydrochemistry indexes of strontium, sodium, potassium, calcium, magnesium, and chlorine in the water body of the main canal were generally stable and had a certain volatility due to seasonal changes, deuterium (2H), oxygen (18O), strontium (87Sr), sulfur(34S) isotopes were the most stable, and were less affected by seasons. For the difference, it was finally determined that the four indexes of chlorine, sodium, chlorine/magnesium ratio, and sodium/magnesium ratio were the most different from the peripheral groundwater. Based on summarizing the hydrochemistry and isotopic characteristic values of the main canal in the middle route of the South-to-North Water Transfer Project, the most representative chemical and isotopic indexes of the main canal are briefed according to three principles for universality, stability, and difference. After comprehensive consideration of several principles and influencing factors, there were 8 indicators of chlorine, sodium, strontium, chlorine/magnesium ratio, sodium/magnesium ratio, deuterium (2H), oxygen (18O), strontium (87Sr) as characteristic indicators with universality, stability, and difference. When water seepage was found in the slope, the chlorine, sodium, chlorine/magnesium ratio, sodium/magnesium ratio, deuterium(2H), and oxygen (18O) could help analyze and judge problems such as side slope seepage quickly. The selection of characteristic indicators could play a good supporting role in the early warning of the main canal project safety and water quality safety.
The topographic features and rivers along the middle route of the South-to-North Water Transfer Project are complex and diverse, and the groundwater burial conditions are different. Once the canal water is mixed or exchanged with groundwater, it would constitute a potential hazard of canal water pollution. Therefore, the traceability of side slope seepage outside the embankment of the main canal is of great significance to the safety of the main canal project and water quality. It is important to select representative "characteristic indexes" as few as possible for real-time and fast monitoring in emergencies.To master the hydrochemistry characteristic index system of the main canal, the changes of 99 hydrochemistry indexes and 5 isotope indexes in 12 sections of the main canal of the middle route of the South-to-North Water Transfer from 2020 to 2022 were systematically analyzed. Along the main canal for more than 1 000 km and according to three principles that can be widely used along the main canal (universality), the stability detection of the main canal itself (stability), and obvious difference with the surrounding water body (difference), identified the specific indexes of the main canal, and then evaluated the normal dynamic range of the characteristic indexes, provided technical support for rapid study and judgment of side slope seepage and engineering safety of the main canal of South-to-North Water Transfer. The results showed that there were 10 hydrochemistry indexes in the main canal water, which could meet the "universality". For stability, the eight hydrochemistry indexes of strontium, sodium, potassium, calcium, magnesium, and chlorine in the water body of the main canal were generally stable and had a certain volatility due to seasonal changes, deuterium (2H), oxygen (18O), strontium (87Sr), sulfur(34S) isotopes were the most stable, and were less affected by seasons. For the difference, it was finally determined that the four indexes of chlorine, sodium, chlorine/magnesium ratio, and sodium/magnesium ratio were the most different from the peripheral groundwater. Based on summarizing the hydrochemistry and isotopic characteristic values of the main canal in the middle route of the South-to-North Water Transfer Project, the most representative chemical and isotopic indexes of the main canal are briefed according to three principles for universality, stability, and difference. After comprehensive consideration of several principles and influencing factors, there were 8 indicators of chlorine, sodium, strontium, chlorine/magnesium ratio, sodium/magnesium ratio, deuterium (2H), oxygen (18O), strontium (87Sr) as characteristic indicators with universality, stability, and difference. When water seepage was found in the slope, the chlorine, sodium, chlorine/magnesium ratio, sodium/magnesium ratio, deuterium(2H), and oxygen (18O) could help analyze and judge problems such as side slope seepage quickly. The selection of characteristic indicators could play a good supporting role in the early warning of the main canal project safety and water quality safety.
2023(1):76-86.
Abstract:
To objectively evaluate the real water consumption and water efficiency link, the water consumption accompanying social commodity consumption was studied based on virtual water analysis. Based on the national and provincial water resource input-output tables. A virtual water flux and comprehensive water use efficiency evaluation model was built to evaluate the virtual water flux. Water consumption accompanying social commodity consumption and comprehensive water use efficiency of China′s provinces in 2007, 2012, and 2017, and the extreme value of water consumption accompanying social commodity consumption in the future was predicted.The results showed that the domestic virtual water input area converged to high-income areas, and the virtual water output area converged to water resources-intensive product production areas. Considering the virtual water circulation, the comprehensive water use efficiency of each province had the same characteristics, and the per capita comprehensive water consumption had a good logarithmic relationship with the level of economic development. The more developed the economy and the higher the living standard of residents, the higher the per capita comprehensive water consumption. Due to changes in the structure of international trade commodities, China′s economic and social water usage was higher than that of water consumption accompanying social commodity consumption before 2012, and then the latter exceeded the former. It is expected that China′s water consumption accompanying social commodity consumption will reach the extreme value of 6 907 billion cubic meters in 2035-2040, 427 billion cubic meters higher than the water usage of economic and social.Water usage of economic and social and water consumption accompanying social commodity consumption, respectively, reflected the scale of water use at the production end and the consumption end. With the improvement of economic and social living standards and the transformation of trade structure, China′s water consumption accompanying social commodity consumption has exceeded the economic and social water usage, and will still show an increasing trend in the future. The difference between the two was mainly solved through virtual water. It is necessary to reasonably optimize the commodity import and export structure to avoid economic and social risks caused by bulk imports.
To objectively evaluate the real water consumption and water efficiency link, the water consumption accompanying social commodity consumption was studied based on virtual water analysis. Based on the national and provincial water resource input-output tables. A virtual water flux and comprehensive water use efficiency evaluation model was built to evaluate the virtual water flux. Water consumption accompanying social commodity consumption and comprehensive water use efficiency of China′s provinces in 2007, 2012, and 2017, and the extreme value of water consumption accompanying social commodity consumption in the future was predicted.The results showed that the domestic virtual water input area converged to high-income areas, and the virtual water output area converged to water resources-intensive product production areas. Considering the virtual water circulation, the comprehensive water use efficiency of each province had the same characteristics, and the per capita comprehensive water consumption had a good logarithmic relationship with the level of economic development. The more developed the economy and the higher the living standard of residents, the higher the per capita comprehensive water consumption. Due to changes in the structure of international trade commodities, China′s economic and social water usage was higher than that of water consumption accompanying social commodity consumption before 2012, and then the latter exceeded the former. It is expected that China′s water consumption accompanying social commodity consumption will reach the extreme value of 6 907 billion cubic meters in 2035-2040, 427 billion cubic meters higher than the water usage of economic and social.Water usage of economic and social and water consumption accompanying social commodity consumption, respectively, reflected the scale of water use at the production end and the consumption end. With the improvement of economic and social living standards and the transformation of trade structure, China′s water consumption accompanying social commodity consumption has exceeded the economic and social water usage, and will still show an increasing trend in the future. The difference between the two was mainly solved through virtual water. It is necessary to reasonably optimize the commodity import and export structure to avoid economic and social risks caused by bulk imports.
2023(1):87-94.
Abstract:
The precision of the new generation Global Precision Measurement (GPM) product and its ability to detect extreme precipitation events in Guangdong Province wad studied, and its substitutability for ground station observation data was discussed, which can provide a reference for the application of GPM products in humid areas in southern China.The Pearl River basin, Hanjiang River basin, eastern Guangdong river basins, and western Guangdong coastal river basins in Guangdong Province were taken as the study area, and the precipitation observed by the national benchmark meteorological station was used as the benchmark data. The precision of GPM and Tropical Rainfall Measuring Mission (TRMM) products were verified by seven indicators, including correlation coefficient, average absolute error, root mean square error, relative deviation, detection rate, air reporting rate, and the success coefficient. The precision of GPM and TRMM products in each sub-basin of Guangdong Province was compared and analyzed. Widely used extreme precipitation indexes were used to describe the characteristics of extreme precipitation in the study area, and the ability of GPM and TRMM was analyzed to detect extreme precipitation events. The results showed that: Taking the measured precipitation on the ground as the reference data, the R values of GPM and TRMM products in Guangdong Province were 0.57 and 0.49 respectively, the BIAS values were 7.93% and 9.13% respectively, and the CSI values were 0.51 and 0.44 respectively, indicating that there was certain deviation between the two remote sensing precipitation products. On the whole, GPM was more accurate than TRMM. Comparing different sub-basins in Guangdong Province, the BIAS values of GPM products and TRMM products in the Pearl River Delta were only 2.28% and 8.72%, respectively, indicating that the two remote sensing precipitation products had the highest accuracy in the Pearl River Delta basin. In terms of detecting extreme precipitation, GPM products had more accurate monitoring of moderate rain, heavy rain, and consecutive days without rain.The new generation of remote sensing precipitation products of GPM had high precision and strong detection ability for extreme precipitation, which were more suitable for flood and drought monitoring in Guangdong Province, and had huge application potential in Guangdong Province, especially in the Pearl River Delta.
The precision of the new generation Global Precision Measurement (GPM) product and its ability to detect extreme precipitation events in Guangdong Province wad studied, and its substitutability for ground station observation data was discussed, which can provide a reference for the application of GPM products in humid areas in southern China.The Pearl River basin, Hanjiang River basin, eastern Guangdong river basins, and western Guangdong coastal river basins in Guangdong Province were taken as the study area, and the precipitation observed by the national benchmark meteorological station was used as the benchmark data. The precision of GPM and Tropical Rainfall Measuring Mission (TRMM) products were verified by seven indicators, including correlation coefficient, average absolute error, root mean square error, relative deviation, detection rate, air reporting rate, and the success coefficient. The precision of GPM and TRMM products in each sub-basin of Guangdong Province was compared and analyzed. Widely used extreme precipitation indexes were used to describe the characteristics of extreme precipitation in the study area, and the ability of GPM and TRMM was analyzed to detect extreme precipitation events. The results showed that: Taking the measured precipitation on the ground as the reference data, the R values of GPM and TRMM products in Guangdong Province were 0.57 and 0.49 respectively, the BIAS values were 7.93% and 9.13% respectively, and the CSI values were 0.51 and 0.44 respectively, indicating that there was certain deviation between the two remote sensing precipitation products. On the whole, GPM was more accurate than TRMM. Comparing different sub-basins in Guangdong Province, the BIAS values of GPM products and TRMM products in the Pearl River Delta were only 2.28% and 8.72%, respectively, indicating that the two remote sensing precipitation products had the highest accuracy in the Pearl River Delta basin. In terms of detecting extreme precipitation, GPM products had more accurate monitoring of moderate rain, heavy rain, and consecutive days without rain.The new generation of remote sensing precipitation products of GPM had high precision and strong detection ability for extreme precipitation, which were more suitable for flood and drought monitoring in Guangdong Province, and had huge application potential in Guangdong Province, especially in the Pearl River Delta.
2023(1):95-106.
Abstract:
Water-saving evaluation is an important measure to implement the idea of “water-saving priority, spatial balance, systematic governance, and two-hand efforts”. Research on regional water-saving evaluation mainly focused on the construction of a water-saving evaluation index system, and statistical indexes are mostly used to construct an evaluation index system, which is lacking in effective grading standards. China began to gradually implement water quota management in the 1970s. A comprehensive and systematic water quota system had been established. A set of regional water-saving evaluation index systems composed of typical investigation indexes and statistical analysis indexes were proposed, given the problems that need to be improved in the current water-saving evaluation. A set of water-saving evaluation standards and methods were explored and established, which was combined with the current water quota. It was applied in the water shortage areas of north China to provide a reference for the development of regional water-saving work.The regional water-saving evaluation index system was established, including the agricultural water index, industrial water index, service water index, domestic water index, and comprehensive water index, according to the principle of representativeness, operability, and easy quantification. The agricultural water index includes water consumption per mu of irrigated crops and water efficiency of irrigation. The industrial water consumption index is comprised of water consumption per unit product of industrial enterprise and water consumption of ten thousand yuan industrial added value. The service industry water consumption index is involved in water consumption per unit of a single service industry. The domestic water consumption index includes the domestic water consumption of urban residents, the domestic water consumption of rural residents, and the leakage rate of the public water supply network. The comprehensive water consumption index consists of water consumption of ten thousand yuan gross domestic product and the proportion of unconventional water use. Among them, water consumption per mu of irrigated crops, water consumption per unit product of industrial enterprise, and water consumption per unit service industry are typical survey indexes, and other indexes are statistical analysis indexes.The evaluation standard of regional water-saving was also established and divided into four levels: advanced, good, general and initial, taking the advanced value, the average value of advanced value and general value, and the general value as three nodes. The regional water-saving evaluation results were divided into four grades according to the total score: advanced (≥90 points), good (≥80-<90 points), medium (≥70-<80 points) and initial (<70 points).The regional water-saving evaluation was scored by a percentage system. The weight of each evaluation index was determined by the analytic hierarchy process. The grading standards of each statistical analysis index were established based on data released by the relevant national or local administrative departments, and the full score and actual score of each index were calculated. The grading standards of typical investigation indexes were established based on national or provincial water quota standards. The water consumption per mu of a single crop, the water consumption per unit product of high water consumption industrial enterprise, and the water consumption per unit of a single service industry were obtained through a typical survey, and the full score and actual score of typical survey indexes were calculated. The total score of the regional water-saving evaluation was obtained by adding and summarizing the scores of each evaluation index. The regional water-saving level was got according to the grading standard.The regional water-saving evaluation method based on water quota was applied to Shandong Province, and the scores of the agricultural water use index, industrial water use index, service water use index, domestic water use index, and comprehensive index were 32.70, 24.18, 14.46, 9.40 and 10.40, respectively. The total score of the regional water-saving evaluation was 91.14. The comprehensive evaluation result was an advanced level of water-saving, according to the grading standard of the regional water-saving evaluation index.Shandong Province was short of water resources. The potential of water-saving in the industry was tapped, the water-saving system and mechanism were improved, and the social water-saving c摯畮獳瑣物祯?睳慮獥?慳琠?瑡桳攠?普潨牡敮晣牥潤測琠?潨晲?瑵桧敨?捴潨略渠瑩牭祰??呭桥敮?牡整獩畯汮琠獯?漠晤?瑥桰攠?牡整来楲漭湳慡汶?睮慧琠敡牮?猠慷癡楴湥杲?散癯慮汴畲慯瑬椠潡湣?晩牯潮浳?㈠ご???瑲潥??は?ち?猠桷潡睴敥摲?瑳桡慶瑩?卧栠慬湥摶潥湬朠?偡牳漠癧楥湮捥敲?睬慬獹?楡湴?瑴桨敥?慦摯癲慥湦捲敯摮?眠慯瑦攠牯?獲愠癣楯湵杮?汲敹瘮攠汔??愠湳摣?瑲桥敳?敯癦愠汲略慧瑩楯潮湡?爠敷獡畴汥瑲猭?睡敶物敮?焠略楶瑡敬?捡潴湩獯楮猠瑢敹渠瑵?睩楮瑧栠?瑨桥攠?慥捧瑩畯慮污?猠楷瑡畴慥瑲椭潳湡??呮桧攠?牶敡杬極潡湴慩汯?眠慭瑥整牨?獤愠癢楡湳来?攠癯慮氠畷慡瑴楥潲渠?浳敥琠桱潵摯?扡愠獦敲摯?漠渲‰眱愵琠整牯?焲田漲琰愠?睥慲獥?昹攰愮猰椵戬氠改‰愮渱搴?愠瀹瀰氮椷挳愬戠氹攰???漬眠改瘰攮爹??椠瑡?楤猠?猱琮椱水氬?湲敥捳数獥獣慴物祶?瑬潹?猠瑩畮搠祓?瑡桮敤?睮慧琠敐牲?獶慩癮楣湥朮?敔癨慥氠畷慡瑴楥潲渭?浡敶瑩桮潧搠獥?楡湬?摡楴晩景敮爠敲湥瑳?牬整杳椠潷湥獲?漠晣??桳楩湳慴??整猠瑷慩扴汨椠獴桨?愠?浣畴汵瑡楬?汷敡癴敥汲?捳潡浶灩牮敧栠敳湩獴極癡整?敯癮愠汩畮愠瑴楨潥渠?楶湡摬敵硡?獩祯獮琠敲浥?晩潯牮?慒?睡桳潯汮敡?捬潥甠湥瑶牡祬??慴湩摯?挠潩浮灤慥牸攠?瑹桳整?睭慳琬攠牧?獡慤癩楮湧朠?汴敡癮敤污獲?楳測?摡楮晤映敥牶敡湬瑵?牴敩杯楮漠湭獥?晨牯潤浳?瑡桲敥?瑶楥浲敹?獩敭牰楯敲獴??呴漠?楯浲瀠牲潥癧敩?瑮桡敬?牷敡汴楥慲戭楳污楶瑩祮?漠晬?扶慥獬椠捥?敡癬慵污畴慩瑯楮漮渠?摨慥琠慥??楬瑵?楴獩?獮甠杭杯敤獥瑬攠摣?瑭潢?獮瑩牮敧渠杴瑹桰敩湣?瑬栠敩?浶敥慳獴畩牧敡浴敩湯瑮?潡普?椠湷摡畴獥瑲爠楱慵汯?睡愠瑷敡牳??慲杯牰楯捳略汤琠畴牯愠汥?睡慬瑵敡牴??慴湨摥?獷敡牴癥楲挭敳?睶慩瑮敧爠??慶湥摬?捯潦渠獷瑡慴湥瑲氠祳?慯摲慴灡瑧?琠潡?瑥桡敳?湩敮攠摮獯?潴晨?睃慨瑩敮牡?猠慔癨楥渠杦?llowing conclusions were drawn. The water-saving evaluation index system of water shortage areas in north China was established, which was composed of typical survey indicators and statistical analysis indicators, considering the main factors such as industrial water use and comprehensive water use that affect the regional water-saving level. The water consumption per unit was obtained through typical investigation and effectively combined with regional statistical indicators. Based on the national and provincial water quota standards, the classification standard of the water-saving evaluation index combined with the water quota was constructed, which made the classification more reasonable and eliminated the influence of the classification of each evaluation index on the evaluation result to a certain extent. Total water consumption in Shandong Province from 2011 to 2020 showed a decreasing-increased-decreasing trend. The water structure had not changed significantly. Among them, agricultural water consumption was the largest. It showed a significant downward trend. In recent years, the water efficiency of Shandong Province had been improved through deep water-saving, and the water-saving level of the in
Water-saving evaluation is an important measure to implement the idea of “water-saving priority, spatial balance, systematic governance, and two-hand efforts”. Research on regional water-saving evaluation mainly focused on the construction of a water-saving evaluation index system, and statistical indexes are mostly used to construct an evaluation index system, which is lacking in effective grading standards. China began to gradually implement water quota management in the 1970s. A comprehensive and systematic water quota system had been established. A set of regional water-saving evaluation index systems composed of typical investigation indexes and statistical analysis indexes were proposed, given the problems that need to be improved in the current water-saving evaluation. A set of water-saving evaluation standards and methods were explored and established, which was combined with the current water quota. It was applied in the water shortage areas of north China to provide a reference for the development of regional water-saving work.The regional water-saving evaluation index system was established, including the agricultural water index, industrial water index, service water index, domestic water index, and comprehensive water index, according to the principle of representativeness, operability, and easy quantification. The agricultural water index includes water consumption per mu of irrigated crops and water efficiency of irrigation. The industrial water consumption index is comprised of water consumption per unit product of industrial enterprise and water consumption of ten thousand yuan industrial added value. The service industry water consumption index is involved in water consumption per unit of a single service industry. The domestic water consumption index includes the domestic water consumption of urban residents, the domestic water consumption of rural residents, and the leakage rate of the public water supply network. The comprehensive water consumption index consists of water consumption of ten thousand yuan gross domestic product and the proportion of unconventional water use. Among them, water consumption per mu of irrigated crops, water consumption per unit product of industrial enterprise, and water consumption per unit service industry are typical survey indexes, and other indexes are statistical analysis indexes.The evaluation standard of regional water-saving was also established and divided into four levels: advanced, good, general and initial, taking the advanced value, the average value of advanced value and general value, and the general value as three nodes. The regional water-saving evaluation results were divided into four grades according to the total score: advanced (≥90 points), good (≥80-<90 points), medium (≥70-<80 points) and initial (<70 points).The regional water-saving evaluation was scored by a percentage system. The weight of each evaluation index was determined by the analytic hierarchy process. The grading standards of each statistical analysis index were established based on data released by the relevant national or local administrative departments, and the full score and actual score of each index were calculated. The grading standards of typical investigation indexes were established based on national or provincial water quota standards. The water consumption per mu of a single crop, the water consumption per unit product of high water consumption industrial enterprise, and the water consumption per unit of a single service industry were obtained through a typical survey, and the full score and actual score of typical survey indexes were calculated. The total score of the regional water-saving evaluation was obtained by adding and summarizing the scores of each evaluation index. The regional water-saving level was got according to the grading standard.The regional water-saving evaluation method based on water quota was applied to Shandong Province, and the scores of the agricultural water use index, industrial water use index, service water use index, domestic water use index, and comprehensive index were 32.70, 24.18, 14.46, 9.40 and 10.40, respectively. The total score of the regional water-saving evaluation was 91.14. The comprehensive evaluation result was an advanced level of water-saving, according to the grading standard of the regional water-saving evaluation index.Shandong Province was short of water resources. The potential of water-saving in the industry was tapped, the water-saving system and mechanism were improved, and the social water-saving c摯畮獳瑣物祯?睳慮獥?慳琠?瑡桳攠?普潨牡敮晣牥潤測琠?潨晲?瑵桧敨?捴潨略渠瑩牭祰??呭桥敮?牡整獩畯汮琠獯?漠晤?瑥桰攠?牡整来楲漭湳慡汶?睮慧琠敡牮?猠慷癡楴湥杲?散癯慮汴畲慯瑬椠潡湣?晩牯潮浳?㈠ご???瑲潥??は?ち?猠桷潡睴敥摲?瑳桡慶瑩?卧栠慬湥摶潥湬朠?偡牳漠癧楥湮捥敲?睬慬獹?楡湴?瑴桨敥?慦摯癲慥湦捲敯摮?眠慯瑦攠牯?獲愠癣楯湵杮?汲敹瘮攠汔??愠湳摣?瑲桥敳?敯癦愠汲略慧瑩楯潮湡?爠敷獡畴汥瑲猭?睡敶物敮?焠略楶瑡敬?捡潴湩獯楮猠瑢敹渠瑵?睩楮瑧栠?瑨桥攠?慥捧瑩畯慮污?猠楷瑡畴慥瑲椭潳湡??呮桧攠?牶敡杬極潡湴慩汯?眠慭瑥整牨?獤愠癢楡湳来?攠癯慮氠畷慡瑴楥潲渠?浳敥琠桱潵摯?扡愠獦敲摯?漠渲‰眱愵琠整牯?焲田漲琰愠?睥慲獥?昹攰愮猰椵戬氠改‰愮渱搴?愠瀹瀰氮椷挳愬戠氹攰???漬眠改瘰攮爹??椠瑡?楤猠?猱琮椱水氬?湲敥捳数獥獣慴物祶?瑬潹?猠瑩畮搠祓?瑡桮敤?睮慧琠敐牲?獶慩癮楣湥朮?敔癨慥氠畷慡瑴楥潲渭?浡敶瑩桮潧搠獥?楡湬?摡楴晩景敮爠敲湥瑳?牬整杳椠潷湥獲?漠晣??桳楩湳慴??整猠瑷慩扴汨椠獴桨?愠?浣畴汵瑡楬?汷敡癴敥汲?捳潡浶灩牮敧栠敳湩獴極癡整?敯癮愠汩畮愠瑴楨潥渠?楶湡摬敵硡?獩祯獮琠敲浥?晩潯牮?慒?睡桳潯汮敡?捬潥甠湥瑶牡祬??慴湩摯?挠潩浮灤慥牸攠?瑹桳整?睭慳琬攠牧?獡慤癩楮湧朠?汴敡癮敤污獲?楳測?摡楮晤映敥牶敡湬瑵?牴敩杯楮漠湭獥?晨牯潤浳?瑡桲敥?瑶楥浲敹?獩敭牰楯敲獴??呴漠?楯浲瀠牲潥癧敩?瑮桡敬?牷敡汴楥慲戭楳污楶瑩祮?漠晬?扶慥獬椠捥?敡癬慵污畴慩瑯楮漮渠?摨慥琠慥??楬瑵?楴獩?獮甠杭杯敤獥瑬攠摣?瑭潢?獮瑩牮敧渠杴瑹桰敩湣?瑬栠敩?浶敥慳獴畩牧敡浴敩湯瑮?潡普?椠湷摡畴獥瑲爠楱慵汯?睡愠瑷敡牳??慲杯牰楯捳略汤琠畴牯愠汥?睡慬瑵敡牴??慴湨摥?獷敡牴癥楲挭敳?睶慩瑮敧爠??慶湥摬?捯潦渠獷瑡慴湥瑲氠祳?慯摲慴灡瑧?琠潡?瑥桡敳?湩敮攠摮獯?潴晨?睃慨瑩敮牡?猠慔癨楥渠杦?llowing conclusions were drawn. The water-saving evaluation index system of water shortage areas in north China was established, which was composed of typical survey indicators and statistical analysis indicators, considering the main factors such as industrial water use and comprehensive water use that affect the regional water-saving level. The water consumption per unit was obtained through typical investigation and effectively combined with regional statistical indicators. Based on the national and provincial water quota standards, the classification standard of the water-saving evaluation index combined with the water quota was constructed, which made the classification more reasonable and eliminated the influence of the classification of each evaluation index on the evaluation result to a certain extent. Total water consumption in Shandong Province from 2011 to 2020 showed a decreasing-increased-decreasing trend. The water structure had not changed significantly. Among them, agricultural water consumption was the largest. It showed a significant downward trend. In recent years, the water efficiency of Shandong Province had been improved through deep water-saving, and the water-saving level of the in
2023(1):107-115.
Abstract:
With the rapid development of the national economy and the continuous urbanization, water demand in social and economic activities has increased sharply. China is a country with a serious shortage of water resources, and the per capita amount of water resources is only 1/4 of the world level. Therefore, some experts pointed out how to solve the water shortage problem that is directly related to eco-environmental security and sustainable economic development. The middle route of the South-to-North Water Transfer Project benefits areas spanning the central and northern regions. These regions have strong economic influence and key areas for eco-environmental protection in China, which also occupy important strategic positions in the national regional development. Therefore, it is of great significance to make a profound study on the driving factors of the relationship between water resource utilization and economic development and predict the evolutionary trend of the future relationship for the sustainable development of ecology and economy in the water-receiving area. The key steps to finding out the driving factors are to reasonably define the state of water resources utilization and economic development and quantitatively investigate the relationship between them.Tapio model of water resources utilization and economic development was constructed by transforming the corresponding variables. The logarithmic mean Divisia index(LMDI) decomposition method was used to study the decoupling state and effect between water resources utilization and economic development, and a system dynamics(SD) prediction model was established.Tapio model was used to analyze the trend of decoupling state between water resources utilization and economic development in water-receiving areas from 2000 to 2020. The results show that it is in a weak decoupling state. From 2000 to 2020, industrial water intensity and industrial structure are the main and secondary influencing factors to maintain the decoupling state, while the level of economic development is an important factor to promote the negative decoupling state. SD model results indicated that in the next ten years, the water consumption and economic development in the water-receiving area will be in a weak decoupling stage.During the development of the water-receiving area in the middle route, the decoupling state between water resources and the economy is still not optimistic. In order to achieve the goal of coordinated development, the work of water-receiving areas should focus on the guidance of laws and policies, financial support, water-saving innovation, science, and technology transformation, etc., which mainly improves the utilization efficiency of water resources.
With the rapid development of the national economy and the continuous urbanization, water demand in social and economic activities has increased sharply. China is a country with a serious shortage of water resources, and the per capita amount of water resources is only 1/4 of the world level. Therefore, some experts pointed out how to solve the water shortage problem that is directly related to eco-environmental security and sustainable economic development. The middle route of the South-to-North Water Transfer Project benefits areas spanning the central and northern regions. These regions have strong economic influence and key areas for eco-environmental protection in China, which also occupy important strategic positions in the national regional development. Therefore, it is of great significance to make a profound study on the driving factors of the relationship between water resource utilization and economic development and predict the evolutionary trend of the future relationship for the sustainable development of ecology and economy in the water-receiving area. The key steps to finding out the driving factors are to reasonably define the state of water resources utilization and economic development and quantitatively investigate the relationship between them.Tapio model of water resources utilization and economic development was constructed by transforming the corresponding variables. The logarithmic mean Divisia index(LMDI) decomposition method was used to study the decoupling state and effect between water resources utilization and economic development, and a system dynamics(SD) prediction model was established.Tapio model was used to analyze the trend of decoupling state between water resources utilization and economic development in water-receiving areas from 2000 to 2020. The results show that it is in a weak decoupling state. From 2000 to 2020, industrial water intensity and industrial structure are the main and secondary influencing factors to maintain the decoupling state, while the level of economic development is an important factor to promote the negative decoupling state. SD model results indicated that in the next ten years, the water consumption and economic development in the water-receiving area will be in a weak decoupling stage.During the development of the water-receiving area in the middle route, the decoupling state between water resources and the economy is still not optimistic. In order to achieve the goal of coordinated development, the work of water-receiving areas should focus on the guidance of laws and policies, financial support, water-saving innovation, science, and technology transformation, etc., which mainly improves the utilization efficiency of water resources.
2023(1):116-126.
Abstract:
Since the last century, the global water cycle processes have been constantly changing, and it is generally believed that the main factors causing this change are climate change and human activities. The impact of this change on the fragile ecological environment of the Loess Plateau is more prominent. In order to improve the ecological environment of the Loess Plateau, the government has implemented a series of ecological construction with planting trees and grasses as the main measures since the last century, especially the implementation of the Grain for Green Project, which has increased the vegetation cover of the region by about 25%, the underlying surface conditions of the basin have changed significantly, and under the joint influence of climate change, the mechanism and characteristics of runoff have changed significantly, the uncertainty of hydrological processes has increased significantly. Therefore, distinguishing the effects between climate change and human activities on hydrological processes is significant importance to understand hydrological changes and to achieve sustainable water resources management in the future.At present, there are three methods to distinguish the impacts of human activities and climate change on hydrological processes, which are the comparative watershed, the empirical equation and the model simulation. The first two-methods have some limitations (high similarity requirement between two watersheds and difficulty in elaborating the interaction mechanism between hydrological processes and influencing factors), the model simulation method, which analyzes the effects of changing environments on hydrological processes through hydrological models driven by remote sensing data, has been widely used worldwide. Based on this, the typical basin of the Grain for Green project - the Yanhe River basin was selected as the study area. In view of the complex underlying surface conditions of the Yanhe River basin, the ecological hydrological model RHESSys that considering the dynamic growth of vegetation was used to simulate the hydrological elements (evapotranspiration, runoff and soil moisture) of the Yanhe River basin before and after Grain for Green Project, and the impacts of human activities and climate change on different hydrological elements were quantified based on different simulation scenarios. The results showed that from 1990 to 2019, the temperature and precipitation in the Yanhe River basin showed an increasing trend, with an increase rate of 0.01 ℃/a and 4.44 mm/a, respectively, and gradually increased from northwest to southeast in space. The land use characteristics of the basin were the transfer of farmland to other types of land. Considering other land use flows, the final area of farmland decreases by 899.31 km2, while the area of grassland and forestland increases by 535.80 km2 and 214.32 km2, respectively. In terms of changes in hydrological elements, the actual evapotranspiration in the basin showed a significant upward trend with an increasing rate of 6.13mm/a after the implementation of the Grain for Green Project, while the runoff and soil water showed a downward trend, but this trend was not significant. Compared with the base period (1990-1999), the contribution rate of land use change caused by human activities to evapotranspiration, runoff and soil water change in P2 period (2000-2009) was 82.66%, ?51.87% and ?55.13%, respectively. With the continuous implementation of the Grain for Green Project, the contribution rate of land use change decreased to 57.64%, ?51.63% and ?52.54% in P3 period (2010-2019). It can be seen that the contribution of land use change to hydrological elements in the Yanhe River basin decreased after the implementation of the Grain for Green Project, but land use change was still the main influencing factor of hydrological elements. This study is critical to the implementation prospect and sustainable development management of the Grain for Green Project on the Loess Plateau, and can provide theoretical support for water resources planning and management in the Loess Plateau.
Since the last century, the global water cycle processes have been constantly changing, and it is generally believed that the main factors causing this change are climate change and human activities. The impact of this change on the fragile ecological environment of the Loess Plateau is more prominent. In order to improve the ecological environment of the Loess Plateau, the government has implemented a series of ecological construction with planting trees and grasses as the main measures since the last century, especially the implementation of the Grain for Green Project, which has increased the vegetation cover of the region by about 25%, the underlying surface conditions of the basin have changed significantly, and under the joint influence of climate change, the mechanism and characteristics of runoff have changed significantly, the uncertainty of hydrological processes has increased significantly. Therefore, distinguishing the effects between climate change and human activities on hydrological processes is significant importance to understand hydrological changes and to achieve sustainable water resources management in the future.At present, there are three methods to distinguish the impacts of human activities and climate change on hydrological processes, which are the comparative watershed, the empirical equation and the model simulation. The first two-methods have some limitations (high similarity requirement between two watersheds and difficulty in elaborating the interaction mechanism between hydrological processes and influencing factors), the model simulation method, which analyzes the effects of changing environments on hydrological processes through hydrological models driven by remote sensing data, has been widely used worldwide. Based on this, the typical basin of the Grain for Green project - the Yanhe River basin was selected as the study area. In view of the complex underlying surface conditions of the Yanhe River basin, the ecological hydrological model RHESSys that considering the dynamic growth of vegetation was used to simulate the hydrological elements (evapotranspiration, runoff and soil moisture) of the Yanhe River basin before and after Grain for Green Project, and the impacts of human activities and climate change on different hydrological elements were quantified based on different simulation scenarios. The results showed that from 1990 to 2019, the temperature and precipitation in the Yanhe River basin showed an increasing trend, with an increase rate of 0.01 ℃/a and 4.44 mm/a, respectively, and gradually increased from northwest to southeast in space. The land use characteristics of the basin were the transfer of farmland to other types of land. Considering other land use flows, the final area of farmland decreases by 899.31 km2, while the area of grassland and forestland increases by 535.80 km2 and 214.32 km2, respectively. In terms of changes in hydrological elements, the actual evapotranspiration in the basin showed a significant upward trend with an increasing rate of 6.13mm/a after the implementation of the Grain for Green Project, while the runoff and soil water showed a downward trend, but this trend was not significant. Compared with the base period (1990-1999), the contribution rate of land use change caused by human activities to evapotranspiration, runoff and soil water change in P2 period (2000-2009) was 82.66%, ?51.87% and ?55.13%, respectively. With the continuous implementation of the Grain for Green Project, the contribution rate of land use change decreased to 57.64%, ?51.63% and ?52.54% in P3 period (2010-2019). It can be seen that the contribution of land use change to hydrological elements in the Yanhe River basin decreased after the implementation of the Grain for Green Project, but land use change was still the main influencing factor of hydrological elements. This study is critical to the implementation prospect and sustainable development management of the Grain for Green Project on the Loess Plateau, and can provide theoretical support for water resources planning and management in the Loess Plateau.
2023(1):127-136.
Abstract:
Under climate change and human activities, the evolution law of water resources in the Songhua River basin had changed drastically. Most of the existing studies were about the influence of climate change and human activities on the measured runoff, and few of them were concerned with the evolution law of surface and groundwater resources in the basin during the freeze-thaw period and the non-freeze-thaw period. In other cold regions with high-intensity human activities, the existing researchers also paid less attention to water resources.The water and energy transfer processes and nitrogen cycle processes model in cold regions (WEP-N) was used to model the water cycle in the Songhua River basin. Based on the WEP-N model, the monthly average surface discharge, soil discharge, base discharge, groundwater recharge, precipitation, and river evaporation of each sub-basin in the basin were calculated. Water resources evaluation method, the surface water resources, non-repeated groundwater resources, and total water resources of the Songhua River basin were evaluated during the whole year, the freeze-thaw period, and the non-freeze-thaw period before and after 1998 (1999-2018 and 1956-1998). The result showed that the annual total water resources, surface water resources, and non-overlapped groundwater resources in the Songhua River basin were 97.74 billion, 83.73 billion, and 1.40 billion m3 during the base period (1956-1998) and 76.04 billion, 62.70 billion and 1.33 billion m3 during the change period (1999-2018), respectively. Due to the change in climate and water consumption, the annual total water resources in the Songhua River basin decreased by 21.7 billion m3, with a rate of change of ?22.2%. Among them, the decrease in surface water resources was 21.02 billion m3, with a rate of change of ?25.1%. The reduction of non-overlapped groundwater resources was 0.68 million m3, with a rate of change of ?4.9%. The decrease in the annual surface water resources accounted for 96.9% of the reduction of total water resources. Groundwater resources (non-overlapped with surface water) accounted for 3.1%. The contribution rates of climate change to the reduction of annual total water resources, surface water resources, and groundwater resources in the Songhua River basin were 81.6%, 74.9%, and 286.6% based on the multifactor attribution analysis respectively. The contribution rates of water use were 18.4%, 25.1%, and ?186.6%, respectively. From the analysis of different periods in the year, the reduction of total water resources during the non-freeze-thaw period accounted for 82.6% of the reduction of annual total water resources. The freeze-thaw period accounted for 17.4%. The decrease in annual total water resources was caused mainly by the decrease in the annual surface water resources. Based on the multifactor attribution analysis, the result showed that climate change was the main factor for the reduction of water resources in the Songhua River basin. From the analysis of different periods in the year, the non-freeze-thaw period was the main period for the reduction of annual water resources. Compared with the Haihe River basin and the Yellow River basin in the north, the reduction extent of water resources and the main influencing factors were different, which mainly depended on the intensity of climate change and human activity. Compared with the Haihe River basin and the Yellow River basin in north China and northwest China, the impact of climate change on the attenuation of water resources in the Songhua River basin was almost the same as that in the Haihe River basin, which was larger than the Yellow River basin. However, the impact of human activities on the attenuation of water resources in the Songhua River basin was smaller than that in the two basins.
Under climate change and human activities, the evolution law of water resources in the Songhua River basin had changed drastically. Most of the existing studies were about the influence of climate change and human activities on the measured runoff, and few of them were concerned with the evolution law of surface and groundwater resources in the basin during the freeze-thaw period and the non-freeze-thaw period. In other cold regions with high-intensity human activities, the existing researchers also paid less attention to water resources.The water and energy transfer processes and nitrogen cycle processes model in cold regions (WEP-N) was used to model the water cycle in the Songhua River basin. Based on the WEP-N model, the monthly average surface discharge, soil discharge, base discharge, groundwater recharge, precipitation, and river evaporation of each sub-basin in the basin were calculated. Water resources evaluation method, the surface water resources, non-repeated groundwater resources, and total water resources of the Songhua River basin were evaluated during the whole year, the freeze-thaw period, and the non-freeze-thaw period before and after 1998 (1999-2018 and 1956-1998). The result showed that the annual total water resources, surface water resources, and non-overlapped groundwater resources in the Songhua River basin were 97.74 billion, 83.73 billion, and 1.40 billion m3 during the base period (1956-1998) and 76.04 billion, 62.70 billion and 1.33 billion m3 during the change period (1999-2018), respectively. Due to the change in climate and water consumption, the annual total water resources in the Songhua River basin decreased by 21.7 billion m3, with a rate of change of ?22.2%. Among them, the decrease in surface water resources was 21.02 billion m3, with a rate of change of ?25.1%. The reduction of non-overlapped groundwater resources was 0.68 million m3, with a rate of change of ?4.9%. The decrease in the annual surface water resources accounted for 96.9% of the reduction of total water resources. Groundwater resources (non-overlapped with surface water) accounted for 3.1%. The contribution rates of climate change to the reduction of annual total water resources, surface water resources, and groundwater resources in the Songhua River basin were 81.6%, 74.9%, and 286.6% based on the multifactor attribution analysis respectively. The contribution rates of water use were 18.4%, 25.1%, and ?186.6%, respectively. From the analysis of different periods in the year, the reduction of total water resources during the non-freeze-thaw period accounted for 82.6% of the reduction of annual total water resources. The freeze-thaw period accounted for 17.4%. The decrease in annual total water resources was caused mainly by the decrease in the annual surface water resources. Based on the multifactor attribution analysis, the result showed that climate change was the main factor for the reduction of water resources in the Songhua River basin. From the analysis of different periods in the year, the non-freeze-thaw period was the main period for the reduction of annual water resources. Compared with the Haihe River basin and the Yellow River basin in the north, the reduction extent of water resources and the main influencing factors were different, which mainly depended on the intensity of climate change and human activity. Compared with the Haihe River basin and the Yellow River basin in north China and northwest China, the impact of climate change on the attenuation of water resources in the Songhua River basin was almost the same as that in the Haihe River basin, which was larger than the Yellow River basin. However, the impact of human activities on the attenuation of water resources in the Songhua River basin was smaller than that in the two basins.
2023(1):137-147.
Abstract:
China has the highest degree of water resources stress. Due to large diverse geographical and climatic characteristics and uneven temporal and spatial distribution of water resources, current water-saving work is still facing problems such as regional imbalance, insufficient potential excavation, and difficult implementation of water-saving measures. Under the background of a series of major water-saving strategies such as the “National Water Conservation Action Plan”, researching water-saving zoning in China is of great significance to scientifically and reasonably promote the implementation of water-saving policies.The current situation of national water-saving zoning in the three major fields including agriculture, industry, and urban living in existing policy documents and academic papers was analyzed in detail through literature research. 31 provincial administrative regions were taken as the basic unit, and the principles of water-saving regionalization were proposed. Fourteen indicators from five aspects were selected to construct the index system of water-saving regionalization including water resources conditions, social and economic conditions, agricultural water use characteristics, industrial water use characteristics and domestic water use characteristics. The coupled method of principal component analysis (PCA) and hierarchical cluster analysis (HCA) was adopted to delimit water-saving zoning. The characteristics of water resources, economy and society, and water use of different fields in the six water-saving zones were analyzed.Results showed that China's water-saving zoning research was mainly concentrated in the field of agriculture, and there were few zoning studies in the field of industrial and urban water-saving. The main reason is that China's agricultural water-saving development started earlier, and agricultural water-saving zoning is greatly affected by regional and environmental factors, which have regularity in large-scale and mesoscale, and differentiation between regions. Industrial water saving is mainly affected by factors including industrial structure, technical conditions, and local policies, whose spatial structure is scattered. It is difficult to find the pattern of spatial differentiation on large-scale, mesoscale, and even small-scale. Urban water saving is mainly affected by factors including water resources conditions, economic and social development level, and living habits. It is regular from the perspective of large-scale and mesoscale and differentiated between regions. However, due to the relatively small proportion of urban domestic water use, the research on its water-saving zoning has not been paid enough attention. By the coupled method of principal component analysis and hierarchical cluster analysis, and tuning small part of the provinces according to the principle of concentration and contiguity in zoning, the 31 provincial administrative regions in China were divided into six water-saving subregions: northeast China (Liaoning, Jilin, Heilongjiang), north China (Beijing, Tianjin, Hebei, Shanxi, Inner Mongolia, Shandong, Henan, Shaanxi), northwest China (Gansu, Qinghai, Ningxia, Xinjiang), southeast coastal area of China (Shanghai, Jiangsu, Zhejiang, Fujian, Guangdong, Guangxi, Hainan), central China (Anhui, Jiangxi, Hubei, Hunan), and southwest China (Chongqing, Sichuan, Guizhou, Yunnan, Tibet). Feature analysis showed that there were significant differences among different regions, and the shortage of water resources and the development of the economy and society played a significant role in promoting water conservation.The six water-saving subregions are consistent with the existing zoning pattern, which shows that the zoning method established has good reliability. The research results can provide strong support for the rational determination of water-saving strategic layout and scientific formulation of water-saving promotion strategies in China.
China has the highest degree of water resources stress. Due to large diverse geographical and climatic characteristics and uneven temporal and spatial distribution of water resources, current water-saving work is still facing problems such as regional imbalance, insufficient potential excavation, and difficult implementation of water-saving measures. Under the background of a series of major water-saving strategies such as the “National Water Conservation Action Plan”, researching water-saving zoning in China is of great significance to scientifically and reasonably promote the implementation of water-saving policies.The current situation of national water-saving zoning in the three major fields including agriculture, industry, and urban living in existing policy documents and academic papers was analyzed in detail through literature research. 31 provincial administrative regions were taken as the basic unit, and the principles of water-saving regionalization were proposed. Fourteen indicators from five aspects were selected to construct the index system of water-saving regionalization including water resources conditions, social and economic conditions, agricultural water use characteristics, industrial water use characteristics and domestic water use characteristics. The coupled method of principal component analysis (PCA) and hierarchical cluster analysis (HCA) was adopted to delimit water-saving zoning. The characteristics of water resources, economy and society, and water use of different fields in the six water-saving zones were analyzed.Results showed that China's water-saving zoning research was mainly concentrated in the field of agriculture, and there were few zoning studies in the field of industrial and urban water-saving. The main reason is that China's agricultural water-saving development started earlier, and agricultural water-saving zoning is greatly affected by regional and environmental factors, which have regularity in large-scale and mesoscale, and differentiation between regions. Industrial water saving is mainly affected by factors including industrial structure, technical conditions, and local policies, whose spatial structure is scattered. It is difficult to find the pattern of spatial differentiation on large-scale, mesoscale, and even small-scale. Urban water saving is mainly affected by factors including water resources conditions, economic and social development level, and living habits. It is regular from the perspective of large-scale and mesoscale and differentiated between regions. However, due to the relatively small proportion of urban domestic water use, the research on its water-saving zoning has not been paid enough attention. By the coupled method of principal component analysis and hierarchical cluster analysis, and tuning small part of the provinces according to the principle of concentration and contiguity in zoning, the 31 provincial administrative regions in China were divided into six water-saving subregions: northeast China (Liaoning, Jilin, Heilongjiang), north China (Beijing, Tianjin, Hebei, Shanxi, Inner Mongolia, Shandong, Henan, Shaanxi), northwest China (Gansu, Qinghai, Ningxia, Xinjiang), southeast coastal area of China (Shanghai, Jiangsu, Zhejiang, Fujian, Guangdong, Guangxi, Hainan), central China (Anhui, Jiangxi, Hubei, Hunan), and southwest China (Chongqing, Sichuan, Guizhou, Yunnan, Tibet). Feature analysis showed that there were significant differences among different regions, and the shortage of water resources and the development of the economy and society played a significant role in promoting water conservation.The six water-saving subregions are consistent with the existing zoning pattern, which shows that the zoning method established has good reliability. The research results can provide strong support for the rational determination of water-saving strategic layout and scientific formulation of water-saving promotion strategies in China.
2023(1):148-159.
Abstract:
To improve the watershed ecological environment, and to realize the sustainable development of water resources, government and scholars have taken a series of investigations. Combined with the flexibility of payment for watershed ecosystem services and the efficient management of government, China proposed watershed ecological compensation and has piloted numerous ecological compensation programs in Xin'an Jiang, Taihu, and other watersheds. The implementation of ecological compensation has played an important role in the improvement of watershed ecology, and it has also impacted the economy, society, and other aspects of watersheds. Therefore, it is crucial to assess the impacts of ecological compensation on the ecology, economy, and society to further promote the implementation and improvement of ecological compensation policy.The evaluation index system, which includes the ecology, economy, social equity, and government investment is established by taking Taihu basin as a case study area. The ecology subsystem includes the per capita water resource, eutrophication index, and cyanobacteria density. The economy subsystem includes the total water supply, per capita disposable income, pollutant emission per unit gross domestic product, and the proportion of tertiary industry. The social equity subsystem includes the disposable income ratio between urban and rural, the health security number of beds per 10 thousand people. The government investment includes the investment in ecological protection. Based on the Dithering Sobol Sequence improved Sparrow Search Algorithm (SobolSSA) and Analytic Network Process (ANP), the evaluation model SobolSSA-ANP is constructed. In the proposed model, the ANP is adopted to analyze the influence relationship among indexes and to determine the evaluation matrix. The SobolSSA model is adopted to optimize the coefficients in the matrix dynamically. Subsequently, the optimized coefficients are input into the AHP model to reconstruct the evaluation matrix and to assess the eco-compensation effect.The results show that: (1) The SobolSSA-ANP improves the consistency and stability of the AHP model, and the evaluation results are more accurate. The CR values decrease by 1~10 orders of magnitude in the multiple ranges given by the experts, and the convergence results are more stable than the AHP model. (2) The implementation of Eco-compensation in the Taihu basin was effective and has improved the ecological environment. Especially, the effect from 2017 is significantly better than that before 2012. (3) The eco-compensation fund is the most important factor that influences the eco-compensation effect. The weight of the eco-compensation fund is 0.191 421, which is higher than the other indexes. Thus, it is necessary to explore market-based and multi-agent eco-compensation mechanisms to broaden the source of eco-compensation funds. (4) The eutrophication index and cyanobacteria density are the second and third important factors, respectively. That is consistent with the actual problems in the Taihu basin. The improvement of the above two factors will improve the ecological environment in the Taihu basin greatly.The implementation of eco-compensation in the Taihu basin has promoted the improvement of ecology, economy, and social equity. However, the eco-compensation funds, the design, and implementation of the eco-compensation mechanism required to be enhanced. It is suggested to promote innovation of eco-compensation mechanisms, explore the multi-agent and market-based eco-compensation, and establish a dynamic evaluation mechanism for the watershed. Meanwhile, establishing the ecological information-sharing mechanism, and transferring the ecological resource to ecological capital promotes the sustainable development of the watershed. The proposed model and results can provide a reference for the evaluation of the watershed eco-compensation effect, and are effective in improving the modernization of the governance capacity. In future research, the blockchain and marker-based eco-compensation mechanism can be coupled together to improve the trading mechanism of ecosystem services.
To improve the watershed ecological environment, and to realize the sustainable development of water resources, government and scholars have taken a series of investigations. Combined with the flexibility of payment for watershed ecosystem services and the efficient management of government, China proposed watershed ecological compensation and has piloted numerous ecological compensation programs in Xin'an Jiang, Taihu, and other watersheds. The implementation of ecological compensation has played an important role in the improvement of watershed ecology, and it has also impacted the economy, society, and other aspects of watersheds. Therefore, it is crucial to assess the impacts of ecological compensation on the ecology, economy, and society to further promote the implementation and improvement of ecological compensation policy.The evaluation index system, which includes the ecology, economy, social equity, and government investment is established by taking Taihu basin as a case study area. The ecology subsystem includes the per capita water resource, eutrophication index, and cyanobacteria density. The economy subsystem includes the total water supply, per capita disposable income, pollutant emission per unit gross domestic product, and the proportion of tertiary industry. The social equity subsystem includes the disposable income ratio between urban and rural, the health security number of beds per 10 thousand people. The government investment includes the investment in ecological protection. Based on the Dithering Sobol Sequence improved Sparrow Search Algorithm (SobolSSA) and Analytic Network Process (ANP), the evaluation model SobolSSA-ANP is constructed. In the proposed model, the ANP is adopted to analyze the influence relationship among indexes and to determine the evaluation matrix. The SobolSSA model is adopted to optimize the coefficients in the matrix dynamically. Subsequently, the optimized coefficients are input into the AHP model to reconstruct the evaluation matrix and to assess the eco-compensation effect.The results show that: (1) The SobolSSA-ANP improves the consistency and stability of the AHP model, and the evaluation results are more accurate. The CR values decrease by 1~10 orders of magnitude in the multiple ranges given by the experts, and the convergence results are more stable than the AHP model. (2) The implementation of Eco-compensation in the Taihu basin was effective and has improved the ecological environment. Especially, the effect from 2017 is significantly better than that before 2012. (3) The eco-compensation fund is the most important factor that influences the eco-compensation effect. The weight of the eco-compensation fund is 0.191 421, which is higher than the other indexes. Thus, it is necessary to explore market-based and multi-agent eco-compensation mechanisms to broaden the source of eco-compensation funds. (4) The eutrophication index and cyanobacteria density are the second and third important factors, respectively. That is consistent with the actual problems in the Taihu basin. The improvement of the above two factors will improve the ecological environment in the Taihu basin greatly.The implementation of eco-compensation in the Taihu basin has promoted the improvement of ecology, economy, and social equity. However, the eco-compensation funds, the design, and implementation of the eco-compensation mechanism required to be enhanced. It is suggested to promote innovation of eco-compensation mechanisms, explore the multi-agent and market-based eco-compensation, and establish a dynamic evaluation mechanism for the watershed. Meanwhile, establishing the ecological information-sharing mechanism, and transferring the ecological resource to ecological capital promotes the sustainable development of the watershed. The proposed model and results can provide a reference for the evaluation of the watershed eco-compensation effect, and are effective in improving the modernization of the governance capacity. In future research, the blockchain and marker-based eco-compensation mechanism can be coupled together to improve the trading mechanism of ecosystem services.
2023(1):160-171.
Abstract:
With the development of social economy, the river ecosystem function is gradually degraded, and the health status of river is increasingly declining. These problems restricted the sustainable development of cities. Therefore, it is of great significance to evaluate the health of urban rivers and studied the response time lag of river ecosystem to water quality change. The response between aquatic ecosystem and environmental factors had nonlinear characteristics and time lag. Macroinvertebrates were used as important indicators for river health assessment because of their obvious response to water environment changes. However, the time scale of most current studies was usually one month or different hydrological seasons within a year. Few studies analyzed the changing trend of benthic integrity on an interannual scale and evaluated its time lag effect on river water quality change.Taking the urban section of Yitong River as an example, macroinvertebrates communities were investigated in 2015 and from 2019 to 2021, and the monitoring data of water quality under the state control section were collected. The benthic index of biotic integrity was used to evaluate the ecological health of the urban section of the Yitong River. Pearson correlation analysis was used to screen the collinearity of water quality factors, and Redundancy analysis was used to analyze the relationship between benthic integrity and water quality, to determine the key water quality factors affecting the benthic index of biotic integrity. The response time lag between benthic integrity and water quality was determined by Pearson correlation analysis. The results showed the following:(1) Aquatic insects and mollusks were the main groups of macroinvertebrates communities in the urban section of the Yitong River. During the study period, the proportion of Oligochaeta decreased from 33.3% to 9.5%, and the proportion of Gastropoda and Valmobranchia increased from 25% to 35.7%. There was no significant difference in the number of benthic species between different months ( P >0.05) and had significant difference between years ( P<0.05);(2)Four biological metrics were selected for the benthic index of biotic integrity, including the total number of taxa, relative abundance of the most dominate taxa, the relative abundance of Diptera and Marglef richness index. Compared with 2015, the benthic index of biotic integrity value increased slightly in 2019, but it was still "fair". In 2020 and 2021, the benthic index of biotic integrity upgraded to "sub-healthy". Two of the three reference sites were "healthy" and one was "sub-healthy". Three sampling sites were "sub-healthy", six were "fair", and only one was "poor"; (3)Total phosphorus was seriously polluted in the urban section of Yitong River, the mean value ranging from 0.06 mg/L to 0.57 mg/L. The first two axes of Redundancy analysis explained 77.96% of the variation in the benthic index of biotic integrity index system. Total phosphorus could explain 57.9% of the benthic index of biotic integrity core index, and the response time of benthic integrity to total phosphorus was about 9 months ( r=?0.88). The conclusions are: (1) The community structure of macroinvertebrates changed in the urban section of Yitong River, the number of species decreased first and then increased, and the main taxa changed from tolerant groups to intolerant groups. (2) The water ecological health status fluctuated and rose annually in the urban section of Yitong River. The health status of the upper reaches was better than that of the lower reaches. (3) Total phosphorus was the key water quality factor affecting the benthic index of biotic integrity in the urban section of Yitong River. The benthic integrity had a time lag in the response of total phosphorus. This study could provide a scientific basis for urban river health assessment and management.
With the development of social economy, the river ecosystem function is gradually degraded, and the health status of river is increasingly declining. These problems restricted the sustainable development of cities. Therefore, it is of great significance to evaluate the health of urban rivers and studied the response time lag of river ecosystem to water quality change. The response between aquatic ecosystem and environmental factors had nonlinear characteristics and time lag. Macroinvertebrates were used as important indicators for river health assessment because of their obvious response to water environment changes. However, the time scale of most current studies was usually one month or different hydrological seasons within a year. Few studies analyzed the changing trend of benthic integrity on an interannual scale and evaluated its time lag effect on river water quality change.Taking the urban section of Yitong River as an example, macroinvertebrates communities were investigated in 2015 and from 2019 to 2021, and the monitoring data of water quality under the state control section were collected. The benthic index of biotic integrity was used to evaluate the ecological health of the urban section of the Yitong River. Pearson correlation analysis was used to screen the collinearity of water quality factors, and Redundancy analysis was used to analyze the relationship between benthic integrity and water quality, to determine the key water quality factors affecting the benthic index of biotic integrity. The response time lag between benthic integrity and water quality was determined by Pearson correlation analysis. The results showed the following:(1) Aquatic insects and mollusks were the main groups of macroinvertebrates communities in the urban section of the Yitong River. During the study period, the proportion of Oligochaeta decreased from 33.3% to 9.5%, and the proportion of Gastropoda and Valmobranchia increased from 25% to 35.7%. There was no significant difference in the number of benthic species between different months ( P >0.05) and had significant difference between years ( P<0.05);(2)Four biological metrics were selected for the benthic index of biotic integrity, including the total number of taxa, relative abundance of the most dominate taxa, the relative abundance of Diptera and Marglef richness index. Compared with 2015, the benthic index of biotic integrity value increased slightly in 2019, but it was still "fair". In 2020 and 2021, the benthic index of biotic integrity upgraded to "sub-healthy". Two of the three reference sites were "healthy" and one was "sub-healthy". Three sampling sites were "sub-healthy", six were "fair", and only one was "poor"; (3)Total phosphorus was seriously polluted in the urban section of Yitong River, the mean value ranging from 0.06 mg/L to 0.57 mg/L. The first two axes of Redundancy analysis explained 77.96% of the variation in the benthic index of biotic integrity index system. Total phosphorus could explain 57.9% of the benthic index of biotic integrity core index, and the response time of benthic integrity to total phosphorus was about 9 months ( r=?0.88). The conclusions are: (1) The community structure of macroinvertebrates changed in the urban section of Yitong River, the number of species decreased first and then increased, and the main taxa changed from tolerant groups to intolerant groups. (2) The water ecological health status fluctuated and rose annually in the urban section of Yitong River. The health status of the upper reaches was better than that of the lower reaches. (3) Total phosphorus was the key water quality factor affecting the benthic index of biotic integrity in the urban section of Yitong River. The benthic integrity had a time lag in the response of total phosphorus. This study could provide a scientific basis for urban river health assessment and management.
2023(1):172-180.
Abstract:
Reservoirs salinization is a common environmental problem in coastal areas. After the salinization of the reservoir, salt will be transferred to the soil, seriously affecting agricultural production. The salinization of reservoir water also has an impact on industrial production. When the salinization of reservoir water cannot meet the industrial water demand, desalting equipment needs to be installed, which increases the cost of enterprises. Thus, it leads to the deterioration of the water quality of the deep fresh water, and even the destruction of the deep groundwater resources, seriously affecting people's daily drinking. Many experts and scholars have carried out relatively comprehensive research on the salinization of coastal reservoirs, but the research on the spatial variation law and salinization mechanism of reservoir salinization is still insufficient. Studying the problem of reservoir salinization can not only save resources and control costs, but also reduce economic losses caused by salinization, improve people's drinking water quality, deepen people's understanding of reservoir salinization, and provide a sufficient theoretical basis for the prevention and control of reservoir salinization. Beidagang Reservoir in Tianjin Binhai area was selected as the research object, and the method of combining field investigation and data analysis was used to sample different locations of the reservoir in summer to analyze the pH of the water body, the content of dissolved total solids (TDS) and Cl? to study the change law of water salinization in different locations to explore the mechanism of reservoir salinization. The study found that along the flow direction from west to east, the concentration of TDS and Cl? presents the distribution characteristics of "upstream gate of the reservoir>downstream gate of the reservoir", while the pH value is the opposite. Along the flow direction, the salinization of the water body shows a gradual weakening trend. The vertical distribution of water body indicators can be divided into two types: "mixed type" and "stratified type". The "mixed" water body is mainly distributed at the intake gate on the west side of the upstream of the reservoir (south bank intake gate, Zhaolianzhuang gate, Maquan intake gate, Dagang Farm gate and Liugangzhuang gate), the Shajingzi gate in the southeast of the reservoir and the outlet gate in the northeast (No. 10 regulating gate and salt drainage gate). The "stratified" water body is mostly distributed in the No. 3 sluice gate. The concentration of TDS and Cl? in the "stratified" water body increases vertically with the increase of depth, and the vertical distribution characteristics of the No. 3 sluice gate are the most obvious. The pH value of sediment presents the distribution trend of "upstream gate of reservoir>downstream gate of reservoir", while the total salt content and Cl? concentration of sediment presents the distribution trend of "downstream gate of reservoir>upstream gate of reservoir". The total salt content and Cl? content of the sediment in upstream of the reservoir are low, and the TDS and Cl? concentrations of the water in upstream of the reservoir are high. However, the total salt content and Cl? content of the sediment in downstream of the reservoir are high, and the concentration of TDS and Cl? in the water in downstream of the reservoir is low, which indicates that the release of sediment salt has an impact on the salinization of the reservoir. Therefore, it is possible to carry out reasonable salt-control operations on the water body at upstream of the reservoir, such as arranging the reasonable water inflow of the inlet gate and the reasonable water outflow of the outlet gate, to further reduce the intensification of water salinization.
Reservoirs salinization is a common environmental problem in coastal areas. After the salinization of the reservoir, salt will be transferred to the soil, seriously affecting agricultural production. The salinization of reservoir water also has an impact on industrial production. When the salinization of reservoir water cannot meet the industrial water demand, desalting equipment needs to be installed, which increases the cost of enterprises. Thus, it leads to the deterioration of the water quality of the deep fresh water, and even the destruction of the deep groundwater resources, seriously affecting people's daily drinking. Many experts and scholars have carried out relatively comprehensive research on the salinization of coastal reservoirs, but the research on the spatial variation law and salinization mechanism of reservoir salinization is still insufficient. Studying the problem of reservoir salinization can not only save resources and control costs, but also reduce economic losses caused by salinization, improve people's drinking water quality, deepen people's understanding of reservoir salinization, and provide a sufficient theoretical basis for the prevention and control of reservoir salinization. Beidagang Reservoir in Tianjin Binhai area was selected as the research object, and the method of combining field investigation and data analysis was used to sample different locations of the reservoir in summer to analyze the pH of the water body, the content of dissolved total solids (TDS) and Cl? to study the change law of water salinization in different locations to explore the mechanism of reservoir salinization. The study found that along the flow direction from west to east, the concentration of TDS and Cl? presents the distribution characteristics of "upstream gate of the reservoir>downstream gate of the reservoir", while the pH value is the opposite. Along the flow direction, the salinization of the water body shows a gradual weakening trend. The vertical distribution of water body indicators can be divided into two types: "mixed type" and "stratified type". The "mixed" water body is mainly distributed at the intake gate on the west side of the upstream of the reservoir (south bank intake gate, Zhaolianzhuang gate, Maquan intake gate, Dagang Farm gate and Liugangzhuang gate), the Shajingzi gate in the southeast of the reservoir and the outlet gate in the northeast (No. 10 regulating gate and salt drainage gate). The "stratified" water body is mostly distributed in the No. 3 sluice gate. The concentration of TDS and Cl? in the "stratified" water body increases vertically with the increase of depth, and the vertical distribution characteristics of the No. 3 sluice gate are the most obvious. The pH value of sediment presents the distribution trend of "upstream gate of reservoir>downstream gate of reservoir", while the total salt content and Cl? concentration of sediment presents the distribution trend of "downstream gate of reservoir>upstream gate of reservoir". The total salt content and Cl? content of the sediment in upstream of the reservoir are low, and the TDS and Cl? concentrations of the water in upstream of the reservoir are high. However, the total salt content and Cl? content of the sediment in downstream of the reservoir are high, and the concentration of TDS and Cl? in the water in downstream of the reservoir is low, which indicates that the release of sediment salt has an impact on the salinization of the reservoir. Therefore, it is possible to carry out reasonable salt-control operations on the water body at upstream of the reservoir, such as arranging the reasonable water inflow of the inlet gate and the reasonable water outflow of the outlet gate, to further reduce the intensification of water salinization.
2023(1):181-189.
Abstract:
In 2012, the State Council of China issued an opinion on the implementation of the strictest water resources management system. It aims to effectively strengthen water pollution prevention and control, improve the quality of the water environment in key river basins, and prevent the eutrophication of rivers and lakes. Danjiangkou Reservoir, as the most important water storage and water supply facility in China, plays a crucial role in the supply of safe water. In recent years, due to the expansion of Danjiangkou Reservoir, the rise of water level, the increase of water storage, and the increase of exogenous nutrient salt content, coupled with the fluctuation of water level, nutrient salt, and other hydrological and environmental conditions brought by the water transfer and water supply of Danjiangkou Reservoir, all will increase the potential risk of reservoir eutrophication. Therefore, strengthening the monitoring and early warning of the water environment is an urgent need for the water safety of the residents in the receiving area and the effective performance of the project.To comprehensively understand the water environment status based on data from 11 monitoring sections from 2015 to 2020, with the help of multivariate data analysis methods such as Mann-Kendall (M-K) trend test, multiple linear stepwise regression analysis, and Pearson correlation analysis, and combined with the improved integrated water quality index (WQI) and integrated trophic level index (TLI), the spatial and temporal distribution patterns and influencing factors of water quality in the Danjiang Reservoir area since the commissioning of the South-North Water Transfer Central Project were explored. According to the research results, from 2015 to 2020, water quality indicators showed obvious seasonal changes and spatial distribution differences in the Danjiang Reservoir area. Water pollution was mainly nitrogen and phosphorus, and the mass concentration of higher areas was mainly on the northern side of the reservoir. The overall water quality in the reservoir area was "good" and in the mesotrophic state, tributary water quality was more seriously polluted than the reservoir area, and the water quality in flood season was worse than that in non-flood season. NH3-N, DO, CODMn, TN and BOD5 were the five key indicators that contribute the most to the water quality of Danku. It is mainly controlled by factors such as rainfall and human activities, and the point and non-point source pollution loads caused by life, industrial and agricultural activities.At this stage, nitrogen and phosphorus are the main sources of pollution in the Danku. In the future, during the treatment of water environment protection in water sources, pollution control of key tributaries such as the Laoguan River and the Danjiang River should be increased to control the discharge of non-point source pollution and provide reference in terms of water dispatch for the South-North Water Transfer Central Project.
In 2012, the State Council of China issued an opinion on the implementation of the strictest water resources management system. It aims to effectively strengthen water pollution prevention and control, improve the quality of the water environment in key river basins, and prevent the eutrophication of rivers and lakes. Danjiangkou Reservoir, as the most important water storage and water supply facility in China, plays a crucial role in the supply of safe water. In recent years, due to the expansion of Danjiangkou Reservoir, the rise of water level, the increase of water storage, and the increase of exogenous nutrient salt content, coupled with the fluctuation of water level, nutrient salt, and other hydrological and environmental conditions brought by the water transfer and water supply of Danjiangkou Reservoir, all will increase the potential risk of reservoir eutrophication. Therefore, strengthening the monitoring and early warning of the water environment is an urgent need for the water safety of the residents in the receiving area and the effective performance of the project.To comprehensively understand the water environment status based on data from 11 monitoring sections from 2015 to 2020, with the help of multivariate data analysis methods such as Mann-Kendall (M-K) trend test, multiple linear stepwise regression analysis, and Pearson correlation analysis, and combined with the improved integrated water quality index (WQI) and integrated trophic level index (TLI), the spatial and temporal distribution patterns and influencing factors of water quality in the Danjiang Reservoir area since the commissioning of the South-North Water Transfer Central Project were explored. According to the research results, from 2015 to 2020, water quality indicators showed obvious seasonal changes and spatial distribution differences in the Danjiang Reservoir area. Water pollution was mainly nitrogen and phosphorus, and the mass concentration of higher areas was mainly on the northern side of the reservoir. The overall water quality in the reservoir area was "good" and in the mesotrophic state, tributary water quality was more seriously polluted than the reservoir area, and the water quality in flood season was worse than that in non-flood season. NH3-N, DO, CODMn, TN and BOD5 were the five key indicators that contribute the most to the water quality of Danku. It is mainly controlled by factors such as rainfall and human activities, and the point and non-point source pollution loads caused by life, industrial and agricultural activities.At this stage, nitrogen and phosphorus are the main sources of pollution in the Danku. In the future, during the treatment of water environment protection in water sources, pollution control of key tributaries such as the Laoguan River and the Danjiang River should be increased to control the discharge of non-point source pollution and provide reference in terms of water dispatch for the South-North Water Transfer Central Project.
2023(1):190-200.
Abstract:
With the continuous intensification of human activities and the continuous development of groundwater science, it is more and more crucial to study the water and solutes transport of fractured soil or rocks in groundwater remediation, agriculture engineering, underground construction, fractured reservoir industry and geological carbon storage (GCS). The different research ideas and research methods are reviewed and the latest research findings on the multi-physics coupled model of groundwater flow and solute transport in fractured rock are summarized.According to the generalization of fractured media, all the fractured models can be divided into (1) Equivalent Porous Model, (2) Multi-continuum Models, (3) Discrete Fracture Model.The Equivalent Porous Model use the equivalent permeability, which makes the model degenerate into a simple model like the ideal porous model, and the validity of the model is often questioned. The Multi-continuum Model is a kind of model that uses the overlapping of multiple media to represent fractured porous media. These different media use different equilibrium equations and transport laws. The calculation of exchange term (for example pore-fracture exchange) is a key of the Multi-continuum Model. These models may achieve a balance in simplification of calculation and capturing different characteristics in fracture and pore matrix. The Discrete Fracture Model is a kind of model that explicitly models fractures. It is generally necessary to determine the specific distribution of each fracture. According to whether the permeability of the pore matrix is considered, it can be further divided into the discrete fracture matrix model (DFM) and discrete fracture network model (DFN). The Discrete Fracture Model has advantages for multi-physics coupling, but the calculation is rather complicated.The multi-physics coupled model can generally be divided into the (1) fully coupled model and (2) non-fully coupled model according to whether each physics is completely bidirectionally coupled.The non-fully coupled model generally refers to that the partial differential equations of different physics are only loosely connected, or only consider the one-direction influence between different physics. The classical solute transport model only considers the convection and dispersion of a solute in the fluid, ignoring the influence of solute concentration on the hydraulic field (such as density change and chemical osmosis). Terzaghi’s consolidation theory and its related models do not consider the fully coupling behavior between the hydraulic and the mechanical field.A fully coupled model needs to consider all the controlling physics of specific behavior and establishes the coupling equations of all variables, and its description of coupling behavior is the most accurate one. The study of the fully coupled model of hydraulic-mechanical behavior begins with Biot. After Biot, researchers modified the equation of rock deformation, and permeability, and considered multiphase flow. More physics fields are also added to the hydraulic-mechanical coupled model. These kinds of models are mainly derived based on the basic principles of rock force balance, fluid mass balance, and momentum conservation, normally named Mechanical Approach models. But when it comes to the study of solutes, due to the gap between geophysics and geochemistry, the Mechanical Approach often lacks unity in the theoretical framework.The Mixture Coupling Theory overcomes the above shortcoming and provides a unified theoretical framework by associating different physics with free energy and taking entropy production as the only driving force. Since the permeability of the pore matrix in fractured rocks is often very low, the coupling effect between fluid, solute and heat transport can not be ignored. The Mixture Coupling Theory can easily give the coupling transport law of different physics using the entropy production in the system. It is shown that Darcy’s law, Fick’s law and Fourier heat transfer law are approximations without considering the coupling of other transport phenomena.It is suggested that the future research direction of the new multi-physics coupling model of fractured groundwater flow and solute transport is mainly concentrated on: Study of the coupling mechanism of different behaviors in multi-space scales and multi-time scales of fracture media; Study on groundwater coupling model under large rock deformation; Accurate description of fracture distribution and random fracture modeling research.
With the continuous intensification of human activities and the continuous development of groundwater science, it is more and more crucial to study the water and solutes transport of fractured soil or rocks in groundwater remediation, agriculture engineering, underground construction, fractured reservoir industry and geological carbon storage (GCS). The different research ideas and research methods are reviewed and the latest research findings on the multi-physics coupled model of groundwater flow and solute transport in fractured rock are summarized.According to the generalization of fractured media, all the fractured models can be divided into (1) Equivalent Porous Model, (2) Multi-continuum Models, (3) Discrete Fracture Model.The Equivalent Porous Model use the equivalent permeability, which makes the model degenerate into a simple model like the ideal porous model, and the validity of the model is often questioned. The Multi-continuum Model is a kind of model that uses the overlapping of multiple media to represent fractured porous media. These different media use different equilibrium equations and transport laws. The calculation of exchange term (for example pore-fracture exchange) is a key of the Multi-continuum Model. These models may achieve a balance in simplification of calculation and capturing different characteristics in fracture and pore matrix. The Discrete Fracture Model is a kind of model that explicitly models fractures. It is generally necessary to determine the specific distribution of each fracture. According to whether the permeability of the pore matrix is considered, it can be further divided into the discrete fracture matrix model (DFM) and discrete fracture network model (DFN). The Discrete Fracture Model has advantages for multi-physics coupling, but the calculation is rather complicated.The multi-physics coupled model can generally be divided into the (1) fully coupled model and (2) non-fully coupled model according to whether each physics is completely bidirectionally coupled.The non-fully coupled model generally refers to that the partial differential equations of different physics are only loosely connected, or only consider the one-direction influence between different physics. The classical solute transport model only considers the convection and dispersion of a solute in the fluid, ignoring the influence of solute concentration on the hydraulic field (such as density change and chemical osmosis). Terzaghi’s consolidation theory and its related models do not consider the fully coupling behavior between the hydraulic and the mechanical field.A fully coupled model needs to consider all the controlling physics of specific behavior and establishes the coupling equations of all variables, and its description of coupling behavior is the most accurate one. The study of the fully coupled model of hydraulic-mechanical behavior begins with Biot. After Biot, researchers modified the equation of rock deformation, and permeability, and considered multiphase flow. More physics fields are also added to the hydraulic-mechanical coupled model. These kinds of models are mainly derived based on the basic principles of rock force balance, fluid mass balance, and momentum conservation, normally named Mechanical Approach models. But when it comes to the study of solutes, due to the gap between geophysics and geochemistry, the Mechanical Approach often lacks unity in the theoretical framework.The Mixture Coupling Theory overcomes the above shortcoming and provides a unified theoretical framework by associating different physics with free energy and taking entropy production as the only driving force. Since the permeability of the pore matrix in fractured rocks is often very low, the coupling effect between fluid, solute and heat transport can not be ignored. The Mixture Coupling Theory can easily give the coupling transport law of different physics using the entropy production in the system. It is shown that Darcy’s law, Fick’s law and Fourier heat transfer law are approximations without considering the coupling of other transport phenomena.It is suggested that the future research direction of the new multi-physics coupling model of fractured groundwater flow and solute transport is mainly concentrated on: Study of the coupling mechanism of different behaviors in multi-space scales and multi-time scales of fracture media; Study on groundwater coupling model under large rock deformation; Accurate description of fracture distribution and random fracture modeling research.
2023(1):201-208.
Abstract:
The optimal channel of rivers dominated by bed load is determined by many factors. In addition to hydrodynamic conditions, it is also closely related to water and sediment inflows and boundary conditions. Since the rivers on the alluvial plains in the United States and India transport overloaded sediment via wide and shallow channels, some foreign scholars believe that wide and shallow channels are ideal for transporting overloaded sediment. However, the sediment transport capacity of the channel is inversely proportional to the width-depth ratio of the channel in the lower reaches of the Yellow River. The reduction of the width-depth ratio can improve the maximum sediment transport capacity of the channel. The relationship between the sediment transport capacity and the optimal section of rivers in different regions manifests different or even opposite relationships, and the channel boundary conditions may be a major factor. When the scouring resistance of the river bank is high, the transverse deformation of the river channel is greatly constrained, and the corresponding channel form is relatively narrow and deep. On the contrary, the river channel is subjected to relatively weak horizontal constraints and is prone to widening. To theoretically determine the influence of different factors on the optimal channel form for alluvial rivers and the corresponding minimum gradient, the methods of hydraulic radius segmentation and the river automatic adjustment variational are used to derive the relationship between bed load sediment transport rate and channel form. By taking the isosceles trapezoid as the cross-section, the relative roughness of the river bank to the river bottom, the bank slope angle, the flow discharge, the sediment transport rate, the median particle size, and the roughness of the river bottom are analyzed to ascertain how they affect the optimal channel form and the minimum gradient, respectively. The results show that the optimal channel form and minimum gradient decline with the increase of relative roughness of river-bank to river-bottom, and rise with the increase of bank slope angle. The increase of flow discharge or river-bottom roughness will cause the minimum gradient to decrease and the optimal channel form to become narrow and deep. The increase in sediment transport rate or median particle size will increase the minimum gradient, but their effects on the evolution of the optimal channel form are different since the increase of sediment transport rate will yield a wide and shallow optimal channel form while the increase of median particle size will make the optimal channel form narrow and deep. This study only conducts a quantitative analysis of the response of the optimal channel form of rivers dominated by bed load and the corresponding minimum gradient to multiple factors of hydrodynamics and river boundary. The response of the sediment transport capacity of the sediment-laden river dominated by suspended load transport to these factors needs further investigation.
The optimal channel of rivers dominated by bed load is determined by many factors. In addition to hydrodynamic conditions, it is also closely related to water and sediment inflows and boundary conditions. Since the rivers on the alluvial plains in the United States and India transport overloaded sediment via wide and shallow channels, some foreign scholars believe that wide and shallow channels are ideal for transporting overloaded sediment. However, the sediment transport capacity of the channel is inversely proportional to the width-depth ratio of the channel in the lower reaches of the Yellow River. The reduction of the width-depth ratio can improve the maximum sediment transport capacity of the channel. The relationship between the sediment transport capacity and the optimal section of rivers in different regions manifests different or even opposite relationships, and the channel boundary conditions may be a major factor. When the scouring resistance of the river bank is high, the transverse deformation of the river channel is greatly constrained, and the corresponding channel form is relatively narrow and deep. On the contrary, the river channel is subjected to relatively weak horizontal constraints and is prone to widening. To theoretically determine the influence of different factors on the optimal channel form for alluvial rivers and the corresponding minimum gradient, the methods of hydraulic radius segmentation and the river automatic adjustment variational are used to derive the relationship between bed load sediment transport rate and channel form. By taking the isosceles trapezoid as the cross-section, the relative roughness of the river bank to the river bottom, the bank slope angle, the flow discharge, the sediment transport rate, the median particle size, and the roughness of the river bottom are analyzed to ascertain how they affect the optimal channel form and the minimum gradient, respectively. The results show that the optimal channel form and minimum gradient decline with the increase of relative roughness of river-bank to river-bottom, and rise with the increase of bank slope angle. The increase of flow discharge or river-bottom roughness will cause the minimum gradient to decrease and the optimal channel form to become narrow and deep. The increase in sediment transport rate or median particle size will increase the minimum gradient, but their effects on the evolution of the optimal channel form are different since the increase of sediment transport rate will yield a wide and shallow optimal channel form while the increase of median particle size will make the optimal channel form narrow and deep. This study only conducts a quantitative analysis of the response of the optimal channel form of rivers dominated by bed load and the corresponding minimum gradient to multiple factors of hydrodynamics and river boundary. The response of the sediment transport capacity of the sediment-laden river dominated by suspended load transport to these factors needs further investigation.
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