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Start-up water hammer protection for long-distance multi-branch pressurized water conveyance systems
2024,44(4):1-6 DOI: 10.3880/j.issn.1006-7647.2024.04.001
Abstract:
In order to study the water hammer problem of a long-distance multi-branch pressurized water conveyance system composed of gravity flow pipelines and pump pressurized pipelines during startup, a mathematical model for calculating the transient process of the water conveyance system was established based on the method of characteristics. Taking an actual project as an example, the impact of different opening time and control strategies of the regulating valve and the pump and its outlet valve on water hammer was calculated during the startup period of the water conveyance system. A water hammer protection scheme using air valves in combination with valve opening was proposed. The results show that the internal water pressure along the water conveyance system can be effectively improved by adopting the strategy that the opening of pump stations lags behind the start of regulating valves and each pump station is opened successively. The water hammer protection scheme using air valves in combination with valve opening can achieve better water hammer protection effect with a smaller size of air valves without affecting the response speed of the water conveyance system.
In order to study the water hammer problem of a long-distance multi-branch pressurized water conveyance system composed of gravity flow pipelines and pump pressurized pipelines during startup, a mathematical model for calculating the transient process of the water conveyance system was established based on the method of characteristics. Taking an actual project as an example, the impact of different opening time and control strategies of the regulating valve and the pump and its outlet valve on water hammer was calculated during the startup period of the water conveyance system. A water hammer protection scheme using air valves in combination with valve opening was proposed. The results show that the internal water pressure along the water conveyance system can be effectively improved by adopting the strategy that the opening of pump stations lags behind the start of regulating valves and each pump station is opened successively. The water hammer protection scheme using air valves in combination with valve opening can achieve better water hammer protection effect with a smaller size of air valves without affecting the response speed of the water conveyance system.
2024,44(4):7-13 DOI: 10.3880/j.issn.1006-7647.2024.04.002
Abstract:
The thermal lattice Boltzmann model was employed to explore wall wettability and liquid viscosity effects on the evolution of an attached-wall cavitation bubble. Force analysis of the contact point was carried out based on the two-particle distribution function of the heat-fluid coupling pseudo-potential LBM cavitation model. It is found that the dynamic contact angle is larger than the equilibrium contact angle throughout the evolution process for a wetting wall, resulting in a hysteresis effect during the growth stage and accelerating the contact point retraction velocity in the collapse stage. For non-wetting walls, the hysteresis effects caused by the unbalanced Young’s force slow down the retraction of the contact points in the early collapse stage and accelerate the retraction in the final collapse stage because of the dramatic interface deformation. An exponential relationship exists between the microjet volume and the cosine function of the equilibrium contact angle at the collapse point. Furthermore, the increase in viscosity leads to a decrease in the jet volume at the collapse point and collapse time is delayed.
The thermal lattice Boltzmann model was employed to explore wall wettability and liquid viscosity effects on the evolution of an attached-wall cavitation bubble. Force analysis of the contact point was carried out based on the two-particle distribution function of the heat-fluid coupling pseudo-potential LBM cavitation model. It is found that the dynamic contact angle is larger than the equilibrium contact angle throughout the evolution process for a wetting wall, resulting in a hysteresis effect during the growth stage and accelerating the contact point retraction velocity in the collapse stage. For non-wetting walls, the hysteresis effects caused by the unbalanced Young’s force slow down the retraction of the contact points in the early collapse stage and accelerate the retraction in the final collapse stage because of the dramatic interface deformation. An exponential relationship exists between the microjet volume and the cosine function of the equilibrium contact angle at the collapse point. Furthermore, the increase in viscosity leads to a decrease in the jet volume at the collapse point and collapse time is delayed.
2024,44(4):14-22 DOI: 10.3880/j.issn.1006-7647.2024.04.003
Abstract:
To study the flood coincidence law of the Lishui River and Songzi River, based on the measured mean daily flow data at the Shimen Station in the Lishui River and at the Xinjiangkou Station and Shadaoguan Station in the Songzi River from 1959 to 2020, a non-uniform GAMLSS model was used to optimize the marginal distributions of the annual maximum flood peak and 7-day continuous annual maximum flood volume. A two-dimensional joint distribution model was constructed based on the Copula function, and the probability of flood coincidence under different combinations of magnitudes was calculated. The results show that the flood sequence in the Song-Li Region has undergone significant variation, and the actual flood characteristics of the region can be described by the time-varying log-normal distribution, Gamma distribution, Weibull distribution, and Copula joint distribution. The typical annual flood encountered in the Song-Li area is mainly the Songzi River flood process and the Lishui River flood. The probability of co-occurrence of the annual maximum flood peaks or 7-day continuous maximum flood volumes of the Lishui and Songzi rivers decreases with the increase of flood magnitude, and the probability of flood coincidence in the Lishui River and the eastern branch of the Songzi Rivers is higher. When a 1 000-year flood occurs in the Lishui River, the probability of co-occurrence of the 1 000-year flood in the Lishui River and small- and medium-sized floods in the Songzi River is higher.
To study the flood coincidence law of the Lishui River and Songzi River, based on the measured mean daily flow data at the Shimen Station in the Lishui River and at the Xinjiangkou Station and Shadaoguan Station in the Songzi River from 1959 to 2020, a non-uniform GAMLSS model was used to optimize the marginal distributions of the annual maximum flood peak and 7-day continuous annual maximum flood volume. A two-dimensional joint distribution model was constructed based on the Copula function, and the probability of flood coincidence under different combinations of magnitudes was calculated. The results show that the flood sequence in the Song-Li Region has undergone significant variation, and the actual flood characteristics of the region can be described by the time-varying log-normal distribution, Gamma distribution, Weibull distribution, and Copula joint distribution. The typical annual flood encountered in the Song-Li area is mainly the Songzi River flood process and the Lishui River flood. The probability of co-occurrence of the annual maximum flood peaks or 7-day continuous maximum flood volumes of the Lishui and Songzi rivers decreases with the increase of flood magnitude, and the probability of flood coincidence in the Lishui River and the eastern branch of the Songzi Rivers is higher. When a 1 000-year flood occurs in the Lishui River, the probability of co-occurrence of the 1 000-year flood in the Lishui River and small- and medium-sized floods in the Songzi River is higher.
2024,44(4):23-30, 58 DOI: 10.3880/j.issn.1006-7647.2024.04.004
Abstract:
To explore the identifiable characteristics and spatiotemporal evolution features of flash droughts in the Jialing River Basin, the spatiotemporal distribution characteristics of flash drought in the basin from 1980 to 2020 was analyzed based on the standardized evaporative stress ratio. Utilizing a density-based clustering algorithm, flash drought patches were extracted and the trajectory changes of the centroids were analyzed. In addition, the abnormal changes of meteorological elements during the outbreak of flash drought were explored by combining meteorological data. The results show that in the northwestern region of the Jialing River Basin, flash droughts exhibit higher intensity and faster development rates, while longer durations exist in the southern part of the basin. The main occurrence of flash drought in the Jialing River Basin is from April to November. The centroids of flash drought events in the basin predominantly migrate towards the northeast and northwest directions. The flash drought in the Jialing River Basin is primarily dominated by a combination of high temperature and precipitation.
To explore the identifiable characteristics and spatiotemporal evolution features of flash droughts in the Jialing River Basin, the spatiotemporal distribution characteristics of flash drought in the basin from 1980 to 2020 was analyzed based on the standardized evaporative stress ratio. Utilizing a density-based clustering algorithm, flash drought patches were extracted and the trajectory changes of the centroids were analyzed. In addition, the abnormal changes of meteorological elements during the outbreak of flash drought were explored by combining meteorological data. The results show that in the northwestern region of the Jialing River Basin, flash droughts exhibit higher intensity and faster development rates, while longer durations exist in the southern part of the basin. The main occurrence of flash drought in the Jialing River Basin is from April to November. The centroids of flash drought events in the basin predominantly migrate towards the northeast and northwest directions. The flash drought in the Jialing River Basin is primarily dominated by a combination of high temperature and precipitation.
2024,44(4):31-37 DOI: 10.3880/j.issn.1006-7647.2024.04.005
Abstract:
Based on the regional environmentally-extended input-output model, the resources consumption and footprint flow of water-land-energy-carbon in the Yellow River Basin, the circulation of regional resources and carbon emissions, and the characteristics of water-land-energy-carbon network were analyzed. The results show that in 2017, the water consumption of nine provinces in the Yellow River Basin was 1 073.69 ×108 m3, the occupied land area was 266.69 ×104 km2, the energy consumption was 6.95×108 t of standard coal, and the carbon emission was 31.57 ×108 t. In the internal footprint flow of the Yellow River Basin, Henan Province has the largest water, land, energy, and carbon footprints and the highest comprehensive recycling utilization rate. Ningxia is the largest virtual water resource supply area. Shanxi Province has the largest transfer of energy and carbon footprints. Shandong Province has the highest land footprint recycling utilization rate. Qinghai Province is the main source of water, land, and energy resources. Sichuan Province has undertaken 19.3×108 t of carbon footprint in the Yellow River Basin. The water-land-energy-carbon system in the Yellow River Basin is dominated by competition, with less control and plunder, and without mutualism. The water-land-energy-carbon correlation system is in a state of high redundancy and low efficiency, and the energy network has the highest efficiency.
Based on the regional environmentally-extended input-output model, the resources consumption and footprint flow of water-land-energy-carbon in the Yellow River Basin, the circulation of regional resources and carbon emissions, and the characteristics of water-land-energy-carbon network were analyzed. The results show that in 2017, the water consumption of nine provinces in the Yellow River Basin was 1 073.69 ×108 m3, the occupied land area was 266.69 ×104 km2, the energy consumption was 6.95×108 t of standard coal, and the carbon emission was 31.57 ×108 t. In the internal footprint flow of the Yellow River Basin, Henan Province has the largest water, land, energy, and carbon footprints and the highest comprehensive recycling utilization rate. Ningxia is the largest virtual water resource supply area. Shanxi Province has the largest transfer of energy and carbon footprints. Shandong Province has the highest land footprint recycling utilization rate. Qinghai Province is the main source of water, land, and energy resources. Sichuan Province has undertaken 19.3×108 t of carbon footprint in the Yellow River Basin. The water-land-energy-carbon system in the Yellow River Basin is dominated by competition, with less control and plunder, and without mutualism. The water-land-energy-carbon correlation system is in a state of high redundancy and low efficiency, and the energy network has the highest efficiency.
2024,44(4):38-44 DOI: 10.3880/j.issn.1006-7647.2024.04.006
Abstract:
Taking the eastern part of the Yellow River Delta and the northern part of the side-bend spur dikes as the study area, the tidal creek network was extracted by visual interpretation based on the eight-phase Landsat series remote sensing images from 1997 to 2021, and the evolution laws of tidal creeks were revealed by analyzing the characteristics of the number, length and density of tidal creeks in different periods. The results show that the whole life cycle of tidal creeks can be divided into four periods: juvenile, young, mature and degraded periods, among which the growth rates of the number and length of tidal creeks are the highest in the juvenile period, which are more than three times those of the young period. In the young period, the number and length of tidal creeks continue to increase, but their growth rate slow down significantly, and the tidal creek network system gradually stabilizes. In the mature period, the development of the tidal creek system is basically completed, and there is no significant change in the length, number and curvature of the tidal creeks. During the degraded period, some tidal creeks shrink, die, and are abandoned, with 10.8% of tidal creeks in group I dying each year from 2005 to 2007.
Taking the eastern part of the Yellow River Delta and the northern part of the side-bend spur dikes as the study area, the tidal creek network was extracted by visual interpretation based on the eight-phase Landsat series remote sensing images from 1997 to 2021, and the evolution laws of tidal creeks were revealed by analyzing the characteristics of the number, length and density of tidal creeks in different periods. The results show that the whole life cycle of tidal creeks can be divided into four periods: juvenile, young, mature and degraded periods, among which the growth rates of the number and length of tidal creeks are the highest in the juvenile period, which are more than three times those of the young period. In the young period, the number and length of tidal creeks continue to increase, but their growth rate slow down significantly, and the tidal creek network system gradually stabilizes. In the mature period, the development of the tidal creek system is basically completed, and there is no significant change in the length, number and curvature of the tidal creeks. During the degraded period, some tidal creeks shrink, die, and are abandoned, with 10.8% of tidal creeks in group I dying each year from 2005 to 2007.
2024,44(4):45-50 DOI: 10.3880/j.issn.1006-7647.2024.04.007
Abstract:
Due to the high sediment content in the operation of the reservoirs in sediment-laden rivers, the effective reservoir storage capacity is often occupied by serious sediment deposition, which leads to the reduction of the service life of the reservoir and the damage to the comprehensive benefit of the reservoir. In order to ensure the sufficient and long-term operation of the sediment laden river reservoirs, three sediment deposition patterns for sediment laden river reservoirs were revealed based on the changes in sediment erosion and deposition during the sediment retention period and normal operation period of the reservoirs, including high beach with deep channel, middle channel and high channel. A coupling design method between the sediment deposition patterns and the storage capacity distribution in the sediment-laden river reservoirs was proposed. The storage capacity distribution model of deep channel for sediment regulation, middle channel for profit promotion, and high channel for flood regulation was established. A new design method of flood control high water level, check flood level and migration level is developed based on the siltation form of high beach and high channel.
Due to the high sediment content in the operation of the reservoirs in sediment-laden rivers, the effective reservoir storage capacity is often occupied by serious sediment deposition, which leads to the reduction of the service life of the reservoir and the damage to the comprehensive benefit of the reservoir. In order to ensure the sufficient and long-term operation of the sediment laden river reservoirs, three sediment deposition patterns for sediment laden river reservoirs were revealed based on the changes in sediment erosion and deposition during the sediment retention period and normal operation period of the reservoirs, including high beach with deep channel, middle channel and high channel. A coupling design method between the sediment deposition patterns and the storage capacity distribution in the sediment-laden river reservoirs was proposed. The storage capacity distribution model of deep channel for sediment regulation, middle channel for profit promotion, and high channel for flood regulation was established. A new design method of flood control high water level, check flood level and migration level is developed based on the siltation form of high beach and high channel.
2024,44(4):51-58 DOI: 10.3880/j.issn.1006-7647.2024.04.008
Abstract:
Conventional intelligent optimization algorithms are inefficient or even impossible in finding feasible solutions to the cascade reservoir optimal operation calculations with small time step and a large number of calculation periods. On this basis, an improved NSGA-Ⅱ algorithm is proposed to solve the problem. Based on the framework of NSGA-Ⅱ algorithm, the improved algorithm introduces reference goal value, potential goal value, offset degree and mutation guiding operator to optimize the population evolution process and to enhance the quality of populations in the evolution process, making the solution set as close as possible to the true Pareto-optimal front. The verification results from a multi-objective optimal operation case study of cascade reservoirs in the Jinxi River Basin of Fujian Province show that the improved NSGA-Ⅱ algorithm has higher computational efficiency and better optimization results compared to other algorithms, demonstrating good practicality.
Conventional intelligent optimization algorithms are inefficient or even impossible in finding feasible solutions to the cascade reservoir optimal operation calculations with small time step and a large number of calculation periods. On this basis, an improved NSGA-Ⅱ algorithm is proposed to solve the problem. Based on the framework of NSGA-Ⅱ algorithm, the improved algorithm introduces reference goal value, potential goal value, offset degree and mutation guiding operator to optimize the population evolution process and to enhance the quality of populations in the evolution process, making the solution set as close as possible to the true Pareto-optimal front. The verification results from a multi-objective optimal operation case study of cascade reservoirs in the Jinxi River Basin of Fujian Province show that the improved NSGA-Ⅱ algorithm has higher computational efficiency and better optimization results compared to other algorithms, demonstrating good practicality.
2024,44(4):59-64 DOI: 10.3880/j.issn.1006-7647.2024.04.009
Abstract:
The noise pollution cannot be avoided for dam deformation, seepage, stress-strain, and other safety monitoring data. It is difficult to achieve excellent denoising effect for the traditional linear noise reduction method. On the basis of reconstructing the phase space of dam safety monitoring data time sequences, with the cross application of local tangent space alignment method, maximum likelihood estimate, adaptive neighborhood and other methods, using the reconstructed phase space as a bridge, and through the extraction of deep information of the monitoring data sequences, the denoised data sequences of dam safety monitoring is obtained. Based on the application of prototype test data, it is evident that the noise reduction effect of the method proposed in this paper is superior to that of the wavelet soft-thresholding method and the fixed neighborhood local tangent space alignment (LTSA) method, demonstrating certain value for engineering applications.
The noise pollution cannot be avoided for dam deformation, seepage, stress-strain, and other safety monitoring data. It is difficult to achieve excellent denoising effect for the traditional linear noise reduction method. On the basis of reconstructing the phase space of dam safety monitoring data time sequences, with the cross application of local tangent space alignment method, maximum likelihood estimate, adaptive neighborhood and other methods, using the reconstructed phase space as a bridge, and through the extraction of deep information of the monitoring data sequences, the denoised data sequences of dam safety monitoring is obtained. Based on the application of prototype test data, it is evident that the noise reduction effect of the method proposed in this paper is superior to that of the wavelet soft-thresholding method and the fixed neighborhood local tangent space alignment (LTSA) method, demonstrating certain value for engineering applications.
2024,44(4):65-71 DOI: 10.3880/j.issn.1006-7647.2024.04.010
Abstract:
In order to solve the problem that traditional dam outlier identification methods mostly rely on single measuring point models and fail to fully consider the spatio-temporal correlation characteristics of deformation between measuring points, which easily leads to misdiagnosis of outliers, a method for identifying concrete dam deformation outliers based on spatio-temporal clustering and deep learning is proposed. This method utilizes the spatio-temporal correlations of deformations between measurement points to perform spatio-temporal clustering and partitioning of the deformation data from the measurement points of concrete dams. Based on the new honey badger algorithm (HBA) and the bidirectional long short-term memory (BiLSTM) neural networks, the HBA-BiLSTM deformation prediction model is established. Deformation outliers in concrete dams are identified based on the deformation values output by the established model and outlier discrimination indices. The results of case validation show that this method has higher accuracy than traditional outlier identification methods.
In order to solve the problem that traditional dam outlier identification methods mostly rely on single measuring point models and fail to fully consider the spatio-temporal correlation characteristics of deformation between measuring points, which easily leads to misdiagnosis of outliers, a method for identifying concrete dam deformation outliers based on spatio-temporal clustering and deep learning is proposed. This method utilizes the spatio-temporal correlations of deformations between measurement points to perform spatio-temporal clustering and partitioning of the deformation data from the measurement points of concrete dams. Based on the new honey badger algorithm (HBA) and the bidirectional long short-term memory (BiLSTM) neural networks, the HBA-BiLSTM deformation prediction model is established. Deformation outliers in concrete dams are identified based on the deformation values output by the established model and outlier discrimination indices. The results of case validation show that this method has higher accuracy than traditional outlier identification methods.
2024,44(4):72-77 DOI: 10.3880/j.issn.1006-7647.2024.04.011
Abstract:
With the gross error detection methods for deformation monitoring data of concrete dams, it is difficult to distinguish between gross errors and sudden data jumps caused by environmental changes. To address this problem, a method for identifying gross errors in dam deformation monitoring data is proposed. This method partitions measuring points using the K-means++ clustering algorithm, and employs the OPTICS clustering algorithm combined with the local outlier factor (LOF) algorithm to detect gross errors in the monitoring data. First, the K-means++ algorithm is used to partition the measurement point areas. Then, the OPTICS and LOF algorithms are used to determine the gross errors. Finally, the real gross errors are identified by comparing the occurrence time of gross errors at different measurement points in the same area. The case study results demonstrate that the method can effectively identify data jumps caused by environmental changes in the monitoring data, significantly improves the accuracy of gross error identification, and reduces the misjudgment rate of gross errors.
With the gross error detection methods for deformation monitoring data of concrete dams, it is difficult to distinguish between gross errors and sudden data jumps caused by environmental changes. To address this problem, a method for identifying gross errors in dam deformation monitoring data is proposed. This method partitions measuring points using the K-means++ clustering algorithm, and employs the OPTICS clustering algorithm combined with the local outlier factor (LOF) algorithm to detect gross errors in the monitoring data. First, the K-means++ algorithm is used to partition the measurement point areas. Then, the OPTICS and LOF algorithms are used to determine the gross errors. Finally, the real gross errors are identified by comparing the occurrence time of gross errors at different measurement points in the same area. The case study results demonstrate that the method can effectively identify data jumps caused by environmental changes in the monitoring data, significantly improves the accuracy of gross error identification, and reduces the misjudgment rate of gross errors.
2024,44(4):78-88 DOI: 10.3880/j.issn.1006-7647.2024.04.012
Abstract:
This paper summarizes the technical schemes and comprehensive benefits of permeable pavement in China from the aspects of policy, standard, method, technology, and benefit evaluation. It divides the development course of China’s permeable pavement into five stages: learning stage, start-up stage, development stage, rapid construction stage, and standardization stage. Current classification methods, evaluation indices, and construction plans for permeable pavement are discussed. The benefits of permeable pavement and the main evaluation methods are analyzed. In view of the lack of directivity in permeable pavement installation and incomplete technical standards in China, some suggestions are put forward, such as improving the evaluation mechanism of permeable pavement, formulating appropriate guiding principles of permeable pavement construction, scientifically and quantitatively analyzing the feasibility of permeable pavement construction, evaluating the rationality of permeable pavement construction in various places, encouraging the construction of permeable pavement in suitable areas, and strengthening the formulation and revision of standards and technical specifications.
This paper summarizes the technical schemes and comprehensive benefits of permeable pavement in China from the aspects of policy, standard, method, technology, and benefit evaluation. It divides the development course of China’s permeable pavement into five stages: learning stage, start-up stage, development stage, rapid construction stage, and standardization stage. Current classification methods, evaluation indices, and construction plans for permeable pavement are discussed. The benefits of permeable pavement and the main evaluation methods are analyzed. In view of the lack of directivity in permeable pavement installation and incomplete technical standards in China, some suggestions are put forward, such as improving the evaluation mechanism of permeable pavement, formulating appropriate guiding principles of permeable pavement construction, scientifically and quantitatively analyzing the feasibility of permeable pavement construction, evaluating the rationality of permeable pavement construction in various places, encouraging the construction of permeable pavement in suitable areas, and strengthening the formulation and revision of standards and technical specifications.
2024,44(4):89-100 DOI: 10.3880/j.issn.1006-7647.2024.04.013
Abstract:
Focusing on the achievements and existing problems in the construction of the comprehensive management digital platform for river and lake chief system, this paper summarizes and analyzes the current status of the platform’s architecture, content, and functionality from four aspects: the digital platform, technical route, database, and platform functions. It provides prospects from various perspectives, including respecting the platform construction rules, enhancing top-level design, establishing a data-sharing mechanism, achieving integrated monitoring of sky, ground, and water, strengthening the application of big data and artificial intelligence technologies, realizing long-term collaborative supervision, compiling technical standards and specifications, and designing platform construction strategies. The research results indicate that the digital platform is fundamental to supporting core business, data sharing and collaborative supervision are the foundation of the digital platform, and intelligence and automation are the technologies or methods adopted by the digital platform.
Focusing on the achievements and existing problems in the construction of the comprehensive management digital platform for river and lake chief system, this paper summarizes and analyzes the current status of the platform’s architecture, content, and functionality from four aspects: the digital platform, technical route, database, and platform functions. It provides prospects from various perspectives, including respecting the platform construction rules, enhancing top-level design, establishing a data-sharing mechanism, achieving integrated monitoring of sky, ground, and water, strengthening the application of big data and artificial intelligence technologies, realizing long-term collaborative supervision, compiling technical standards and specifications, and designing platform construction strategies. The research results indicate that the digital platform is fundamental to supporting core business, data sharing and collaborative supervision are the foundation of the digital platform, and intelligence and automation are the technologies or methods adopted by the digital platform.
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2019,39(1):1-6, DOI: 10.3880/j.issn.1006-7647.2019.01.001
Abstract:
Since flood is formed by storm, flood forecasting is the continuity of precipitation prediction. In recent 30 years, numerical weather prediction has made great advance, but the attempt to apply watershed hydrological model in flood forecasting is slow. The reasons for the different accuracies between numerical weather prediction and flood forecasting are investigated. Successful experience of numerical weather prediction and the problems of watershed hydrological model in the application of flood forecasting are discussed by means of comparison of the weather model and the watershed hydrological model. Problems discussed are the prediction methods and the forecasting time, the initial fields and the boundary value fields, data assimilation and data fusion. It is expected that great inspirations to flood forecasting can be obtained from the successful experience of numerical weather prediction. In the near future, seamless connection can be realized between weather prediction and flood forecasting, and as a result, the accuracy of flood forecasting can thus be improved and the forecasting time can be extended.
Since flood is formed by storm, flood forecasting is the continuity of precipitation prediction. In recent 30 years, numerical weather prediction has made great advance, but the attempt to apply watershed hydrological model in flood forecasting is slow. The reasons for the different accuracies between numerical weather prediction and flood forecasting are investigated. Successful experience of numerical weather prediction and the problems of watershed hydrological model in the application of flood forecasting are discussed by means of comparison of the weather model and the watershed hydrological model. Problems discussed are the prediction methods and the forecasting time, the initial fields and the boundary value fields, data assimilation and data fusion. It is expected that great inspirations to flood forecasting can be obtained from the successful experience of numerical weather prediction. In the near future, seamless connection can be realized between weather prediction and flood forecasting, and as a result, the accuracy of flood forecasting can thus be improved and the forecasting time can be extended.
2020,40(1):1-9, DOI: 10.3880/j.issn.1006-7647.2020.01.001
Abstract:
In order to reasonably synthesize the carrying capacity of regional water resources by the four elements of water quantity, water quality, water space and stream flow, a water resources carrying capacity evaluation model based on the four elements and a risk matrix(QQSS-RM)was proposed. Firstly, 48 preliminary evaluation indicators under the subsystem of quantity-quality-space-stream were constructed and the weight of each evaluation index in the four elements was calculated by expert consultation information method and genetic analytic hierarchy process. Through screening and analysis, 8 comprehensive evaluation indexes were obtained to construct the evaluation index system for the regional water resources carrying capacity. Secondly, 4 evaluation grade criteria of 8 comprehensive evaluation indexes were obtained by referring to relevant literature and expert opinions. Finally, an evaluation model of water resources carrying capacity based on QQSS-RM was constructed, which was applied to three third grade zones of water resources in the Xiliao River Basin. The results show that the water resources carrying capacity evaluation level of Xilamulun River and Laoha River, Wulijimulun River and the downstream of Xiliao River are overloaded, critical overloaded and overloaded respectively, showing a poor water resources carrying capacity of the Xiliao River Basin. The evaluation results are basically consistent with the current status of the Xiliao River Basin, indicating that the QQSS-RM model has better application value in regional water resources carrying capacity evaluation.
In order to reasonably synthesize the carrying capacity of regional water resources by the four elements of water quantity, water quality, water space and stream flow, a water resources carrying capacity evaluation model based on the four elements and a risk matrix(QQSS-RM)was proposed. Firstly, 48 preliminary evaluation indicators under the subsystem of quantity-quality-space-stream were constructed and the weight of each evaluation index in the four elements was calculated by expert consultation information method and genetic analytic hierarchy process. Through screening and analysis, 8 comprehensive evaluation indexes were obtained to construct the evaluation index system for the regional water resources carrying capacity. Secondly, 4 evaluation grade criteria of 8 comprehensive evaluation indexes were obtained by referring to relevant literature and expert opinions. Finally, an evaluation model of water resources carrying capacity based on QQSS-RM was constructed, which was applied to three third grade zones of water resources in the Xiliao River Basin. The results show that the water resources carrying capacity evaluation level of Xilamulun River and Laoha River, Wulijimulun River and the downstream of Xiliao River are overloaded, critical overloaded and overloaded respectively, showing a poor water resources carrying capacity of the Xiliao River Basin. The evaluation results are basically consistent with the current status of the Xiliao River Basin, indicating that the QQSS-RM model has better application value in regional water resources carrying capacity evaluation.
2020,40(2):1-5, DOI: 10.3880/j.issn.1006-7647.2020.02.001
Abstract:
Problems exist in the construction and management of ecological irrigation districts, such as low efficiency in industry and resources, irrigation water deterioration and decreased ecological diversity. Based on the theoretical guidance of the rural revitalization strategy and its 20 words general requirements, construction and management of ecological irrigation districts under the guidance of the rural revitalization strategy were discussed. Three red lines for the construction and management of irrigation districts were proposed, including the baseline of agricultural quality and production, the baseline of ecological environment and the upper limit of resources development and utilization. The ecological irrigation districts should develop in the direction of effective supply of food production and other products, perfection in ecological environmental landscape, protection and high-efficiency utilization of resources. This paper provides scientific references of sustainable and green development for ecological irrigation districts.
Problems exist in the construction and management of ecological irrigation districts, such as low efficiency in industry and resources, irrigation water deterioration and decreased ecological diversity. Based on the theoretical guidance of the rural revitalization strategy and its 20 words general requirements, construction and management of ecological irrigation districts under the guidance of the rural revitalization strategy were discussed. Three red lines for the construction and management of irrigation districts were proposed, including the baseline of agricultural quality and production, the baseline of ecological environment and the upper limit of resources development and utilization. The ecological irrigation districts should develop in the direction of effective supply of food production and other products, perfection in ecological environmental landscape, protection and high-efficiency utilization of resources. This paper provides scientific references of sustainable and green development for ecological irrigation districts.
2020,40(3):1-7, DOI: 10.3880/j.issn.1006-7647.2020.03.001
Abstract:
Spring ecological water requirement for the fishes in the Yellow River Estuary should meet the needs of the habitat and spawning ground of freshwater fishes, channel of migratory fishes, and spawning ground of offshore migratory fishes. According to the living habit of fishes, the time of runoff propagation, the mixing time of fresh water and salt water, and the discharge feature since the operation of the Xiaolangdi Reservoir, key attention should be paid to the water requirement from March to May. A minimum ecological flow discharge of 240 m3/s is needed according to the living habit of fishes and the continuity of the migration channel. A flow discharge pulse with a peak of 890 m3/s, lasting for 8d in the middle stage of April is also needed considering the pulse characteristics in nature period. In this condition, the runoff in spring is 21. 6×108 m3, satisfying the requirement of 21×108 m3 for the low salt spawning condition of offshore migratory fishes. The mean annual spring runoff is 21×108 m3 since the operation of the Xiaolangdi Reservoir. It is of great feasibility to satisfy the fish ecological water requirement by optimizing the annual or the interannual operation modes.
Spring ecological water requirement for the fishes in the Yellow River Estuary should meet the needs of the habitat and spawning ground of freshwater fishes, channel of migratory fishes, and spawning ground of offshore migratory fishes. According to the living habit of fishes, the time of runoff propagation, the mixing time of fresh water and salt water, and the discharge feature since the operation of the Xiaolangdi Reservoir, key attention should be paid to the water requirement from March to May. A minimum ecological flow discharge of 240 m3/s is needed according to the living habit of fishes and the continuity of the migration channel. A flow discharge pulse with a peak of 890 m3/s, lasting for 8d in the middle stage of April is also needed considering the pulse characteristics in nature period. In this condition, the runoff in spring is 21. 6×108 m3, satisfying the requirement of 21×108 m3 for the low salt spawning condition of offshore migratory fishes. The mean annual spring runoff is 21×108 m3 since the operation of the Xiaolangdi Reservoir. It is of great feasibility to satisfy the fish ecological water requirement by optimizing the annual or the interannual operation modes.
2015,35(4):1-5, DOI: 10.3880/j.issn.1006-7647.2015.04.001
Abstract:
Through the analysis of parameters and structure, it was found that the description of storm water management model(SWMM) on the process of rainfall-runoff formation in urban areas is consistent with urban runoff yield and concentration rule. The physical concept of SWMM is clear because the runoff yield analytical methods are based on hydrology, and concentration analytical methods are based on hydraulics. The parameters of SWMM almost have geometric or physical meanings, but there are some complementary(or dependency) relationships among some parameters. Therefore, it is necessary to reduce the influence of the equifinality for different parameters on parameter calibration. The composition of the process of rainfall-runoff formation in catchment area exit using the method of simultaneous summation shows that the interference between stormflows from different areas is neglected.
Through the analysis of parameters and structure, it was found that the description of storm water management model(SWMM) on the process of rainfall-runoff formation in urban areas is consistent with urban runoff yield and concentration rule. The physical concept of SWMM is clear because the runoff yield analytical methods are based on hydrology, and concentration analytical methods are based on hydraulics. The parameters of SWMM almost have geometric or physical meanings, but there are some complementary(or dependency) relationships among some parameters. Therefore, it is necessary to reduce the influence of the equifinality for different parameters on parameter calibration. The composition of the process of rainfall-runoff formation in catchment area exit using the method of simultaneous summation shows that the interference between stormflows from different areas is neglected.
2019,39(3):18-23, DOI: 10.3880/j.issn.1006-7647.2019.03.004
Abstract:
In order to comprehensively understand the current status of global hydropower development, to analyze the development potential of hydropower markets in various countries, and to guide hydropower enterprises to explore the international market, the world is divided into six regions, including North America, South America, Africa, Europe, Central and South Asia, East Asia and the Pacific Rim. The current status of hydropower development in various regions of the world, as well as the corresponding status and development goals in key countries are elaborated. Based on the water resources and the development situation, the exploring potential of the global hydropower market is analyzed. The results show that the total installed capacity of hydropower in the world continues to increase but the annual increment shows a downward trend. The hydropower development potential in Africa, South Asia and Southeast Asia is relatively large. In terms of technology development, the countries such as Indonesia, Peru, DR Congo, Tajikistan, Nepal, Angola, Myanmar and Bolivia, etc. , have broad prospects for future hydropower markets.
In order to comprehensively understand the current status of global hydropower development, to analyze the development potential of hydropower markets in various countries, and to guide hydropower enterprises to explore the international market, the world is divided into six regions, including North America, South America, Africa, Europe, Central and South Asia, East Asia and the Pacific Rim. The current status of hydropower development in various regions of the world, as well as the corresponding status and development goals in key countries are elaborated. Based on the water resources and the development situation, the exploring potential of the global hydropower market is analyzed. The results show that the total installed capacity of hydropower in the world continues to increase but the annual increment shows a downward trend. The hydropower development potential in Africa, South Asia and Southeast Asia is relatively large. In terms of technology development, the countries such as Indonesia, Peru, DR Congo, Tajikistan, Nepal, Angola, Myanmar and Bolivia, etc. , have broad prospects for future hydropower markets.
2019,39(4):1-6, DOI: 10.3880/j.issn.1006-7647.2019.04.001
Abstract:
To examine the damage causes of warping dams and their impacts on sediment delivery into the Yellow River, the characteristics of the rainstorm process at August 17 and the inflow of water-sediment into the Yellow River were obtained based on the field investigation results of 19 warping dam breaches and the data of hydrological stations and rainfall stations in Xiliugou and Hantaichuan watersheds. According to the structure and operation characteristics of the warping dams, combined with the detailed investigation of the flood-induced damage situation, especially the erosion form at the break sites, the causes of flood-induced damage were analyzed from the aspects of rainfall, planning, design, construction and operation management of the warping dams. The break modes and sand-blocking effects of the warping dams were qualitatively presented. Suggestions are proposed, including optimizing dam-system layout and construction standard, improving the structure of drainage structures, strengthening construction quality management, and paying attention to non-engineering measures such as early warning and prediction.
To examine the damage causes of warping dams and their impacts on sediment delivery into the Yellow River, the characteristics of the rainstorm process at August 17 and the inflow of water-sediment into the Yellow River were obtained based on the field investigation results of 19 warping dam breaches and the data of hydrological stations and rainfall stations in Xiliugou and Hantaichuan watersheds. According to the structure and operation characteristics of the warping dams, combined with the detailed investigation of the flood-induced damage situation, especially the erosion form at the break sites, the causes of flood-induced damage were analyzed from the aspects of rainfall, planning, design, construction and operation management of the warping dams. The break modes and sand-blocking effects of the warping dams were qualitatively presented. Suggestions are proposed, including optimizing dam-system layout and construction standard, improving the structure of drainage structures, strengthening construction quality management, and paying attention to non-engineering measures such as early warning and prediction.
2019,39(2):1-6, DOI: 10.3880/j.issn.1006-7647.2019.02.001
Abstract:
To cope with the new challenges of environmental flow research under hydrology, climate and ecosystem changes, research results from both China and abroad have been summarized. Five aspects of shortcomings in the current environmental flow research are pointed out, which also belong to frontier problems and challenges, including(1)Global environmental change and instability; (2)Dynamic simulation of eco-hydrological process in which the transition of hydrological regime from static evaluation to dynamic characteristic evaluation is the key; (3)Characteristics of eco-hydrological relationship in which the coupling research of ecosystem state, process variables and species characteristics, and the research of ecological characteristics, spatial and temporal scales of environmental flows are the key points; (4)Key indicators in environmental flow evaluation; (5)Ecology extension of environmental flow forecasting. To solve these problems, research directions of environmental flows in the background of the Anthropocene are proposed. Dynamic adaptive management of ecological objectives and basic research of ecology from local to reginal areas should be strengthened. Mechanisms of eco-hydrological response based on process should be completed and phased implementation of non-hydrological indicator coupling should be intensified. Evaluation and application of environmental flows under adaptive management should be strengthened to guarantee ecological integrity.
To cope with the new challenges of environmental flow research under hydrology, climate and ecosystem changes, research results from both China and abroad have been summarized. Five aspects of shortcomings in the current environmental flow research are pointed out, which also belong to frontier problems and challenges, including(1)Global environmental change and instability; (2)Dynamic simulation of eco-hydrological process in which the transition of hydrological regime from static evaluation to dynamic characteristic evaluation is the key; (3)Characteristics of eco-hydrological relationship in which the coupling research of ecosystem state, process variables and species characteristics, and the research of ecological characteristics, spatial and temporal scales of environmental flows are the key points; (4)Key indicators in environmental flow evaluation; (5)Ecology extension of environmental flow forecasting. To solve these problems, research directions of environmental flows in the background of the Anthropocene are proposed. Dynamic adaptive management of ecological objectives and basic research of ecology from local to reginal areas should be strengthened. Mechanisms of eco-hydrological response based on process should be completed and phased implementation of non-hydrological indicator coupling should be intensified. Evaluation and application of environmental flows under adaptive management should be strengthened to guarantee ecological integrity.
2020,40(1):17-24, DOI: 10.3880/j.issn.1006-7647.2020.01.003
Abstract:
The geological disaster chain related to landslide dams has caused a lot of economic losses and casualties to China every year. Based on data statistics, the triggering factors and distribution rules of landslide dams in China in the past 10 years were analyzed. The results show that, there has been more than 100 recorded landslide dams in China. Earthquakes and heavy rainfalls are the main trigger factors, since they account for more than 90% of the total statistics. In terms of geographical distribution, Southwestern China is the heavy disaster-area of hazards related to landslide dams, and the landslide dam number accounts for more than 80% of the total statistics. The number of landslide dams in Sichuan Province is far more than that of other provinces, as it has suffered from the Wenchuan earthquake and the Lushan earthquake. Taiwan Province ranks the second, since there are 11 landslide dams recorded in the past 10 years due to the impact of typhoons yearly, accounting for 10. 2% of the total, followed by Yunnan, Chongqing and other provinces. In terms of temporal distribution, the number of landslide dams is basically fluctuating within the normal range except for the year 2008.
The geological disaster chain related to landslide dams has caused a lot of economic losses and casualties to China every year. Based on data statistics, the triggering factors and distribution rules of landslide dams in China in the past 10 years were analyzed. The results show that, there has been more than 100 recorded landslide dams in China. Earthquakes and heavy rainfalls are the main trigger factors, since they account for more than 90% of the total statistics. In terms of geographical distribution, Southwestern China is the heavy disaster-area of hazards related to landslide dams, and the landslide dam number accounts for more than 80% of the total statistics. The number of landslide dams in Sichuan Province is far more than that of other provinces, as it has suffered from the Wenchuan earthquake and the Lushan earthquake. Taiwan Province ranks the second, since there are 11 landslide dams recorded in the past 10 years due to the impact of typhoons yearly, accounting for 10. 2% of the total, followed by Yunnan, Chongqing and other provinces. In terms of temporal distribution, the number of landslide dams is basically fluctuating within the normal range except for the year 2008.
2021,41(2):1-7, DOI: 10.3880/j.issn.1006-7647.2021.02.001
Abstract:
An improved corridor constraint and IPSO-DPSA algorithm were proposed to solve the problem of morphological distortion of the dispatching line in the reservoir operation optimization process. Based on the hybrid algorithm of particle swarm optimization and dynamic programming successive approximation, this method optimizes the evolution process by introducing improved corridor constraints, special individual evolution mode, external elite set strategy, making the solution set as close as possible to the Pareto-optimal front of the multi-objective problem. The case study of the multi-objective optimization problem of the scheduling graph of the Chitan Reservoir shows that the algorithm can effectively control the morphological distortion of the dispatching line in the optimization process, and has good optimization performance.
An improved corridor constraint and IPSO-DPSA algorithm were proposed to solve the problem of morphological distortion of the dispatching line in the reservoir operation optimization process. Based on the hybrid algorithm of particle swarm optimization and dynamic programming successive approximation, this method optimizes the evolution process by introducing improved corridor constraints, special individual evolution mode, external elite set strategy, making the solution set as close as possible to the Pareto-optimal front of the multi-objective problem. The case study of the multi-objective optimization problem of the scheduling graph of the Chitan Reservoir shows that the algorithm can effectively control the morphological distortion of the dispatching line in the optimization process, and has good optimization performance.
2019,39(3):1-5, DOI: 10.3880/j.issn.1006-7647.2019.03.001
Abstract:
The reservoirs(Xiluodu, Xiangjiaba, Zipingpu, Pubugou, and Tingzikou)in the upper Yangtze River were considered as the object of study. A nonlinear safety degree strategy for the joint flood control system of the multi-reservoirs in the upper Yangtze River was proposed, based on which a flood storage capacity optimization distribution model for multi-reservoirs was constructed and an in-depth discussion for the flood control effect of the nonlinear safety degree strategy was conducted. The results show that compared with linear safety degree strategy of multi-reservoirs, the flood control capacity of Xiluodu reservoir can be less consumed by increasing the usage of the flood control capacity in other reservoirs by the nonlinear strategy in the condition that the flood control effect of the downstream is not deteriorated. The application of the nonlinear safety degree strategy can relatively balance the flood storage capacity allocation of the reservoirs, make the reservoirs share the flood risk of the flood control areas, give full play to the flood control benefits of the reservoirs, and ensure the stable and safe operation of the multi-reservoir system.
The reservoirs(Xiluodu, Xiangjiaba, Zipingpu, Pubugou, and Tingzikou)in the upper Yangtze River were considered as the object of study. A nonlinear safety degree strategy for the joint flood control system of the multi-reservoirs in the upper Yangtze River was proposed, based on which a flood storage capacity optimization distribution model for multi-reservoirs was constructed and an in-depth discussion for the flood control effect of the nonlinear safety degree strategy was conducted. The results show that compared with linear safety degree strategy of multi-reservoirs, the flood control capacity of Xiluodu reservoir can be less consumed by increasing the usage of the flood control capacity in other reservoirs by the nonlinear strategy in the condition that the flood control effect of the downstream is not deteriorated. The application of the nonlinear safety degree strategy can relatively balance the flood storage capacity allocation of the reservoirs, make the reservoirs share the flood risk of the flood control areas, give full play to the flood control benefits of the reservoirs, and ensure the stable and safe operation of the multi-reservoir system.
2019,39(3):6-10, DOI: 10.3880/j.issn.1006-7647.2019.03.002
Abstract:
Aiming at the complex problems of water resources in Beijing-Tianjin-Hebei region, an overall regulation and control idea based on the theory of virtuous circulation of water resources is proposed, which includes the smooth circulation of natural water resources and the cooperative equilibrium of social water resources circulation. Coping strategies are put forward in five aspects, including nature-enriched water regulation, combination of concentrated and sporadic sewage treatment, unified regulation, water consumption management, and synergetic utilization of water market. The present study is aimed at achieving virtuous circulation to support sustainable utilization of water resources and green development.
Aiming at the complex problems of water resources in Beijing-Tianjin-Hebei region, an overall regulation and control idea based on the theory of virtuous circulation of water resources is proposed, which includes the smooth circulation of natural water resources and the cooperative equilibrium of social water resources circulation. Coping strategies are put forward in five aspects, including nature-enriched water regulation, combination of concentrated and sporadic sewage treatment, unified regulation, water consumption management, and synergetic utilization of water market. The present study is aimed at achieving virtuous circulation to support sustainable utilization of water resources and green development.
2017,37(4):1-7, DOI: 10.3880/j.issn.1006-7647.2017.04.001
Abstract:
The hydrological principle of the structure and parameters of watershed hydrological models, the physical coupling relationship between the structure and parameters, and the essential difference between lumped and distributed watershed hydrological models were investigated. The characteristics of the solution methods for these two models, and the reasons causing the phenomenon of equifinality for different parameters during the calibration of the watershed hydrological models, as well as methods to alleviate the effects of this phenomenon, are discussed. A method for verification and comparison of the watershed hydrological models is proposed.
The hydrological principle of the structure and parameters of watershed hydrological models, the physical coupling relationship between the structure and parameters, and the essential difference between lumped and distributed watershed hydrological models were investigated. The characteristics of the solution methods for these two models, and the reasons causing the phenomenon of equifinality for different parameters during the calibration of the watershed hydrological models, as well as methods to alleviate the effects of this phenomenon, are discussed. A method for verification and comparison of the watershed hydrological models is proposed.
2019,39(1):7-14, DOI: 10.3880/j.issn.1006-7647.2019.01.002
Abstract:
The goal of water governance is specified from five dimensions, including resources, economy, sociality, ecology and environment. The evaluation index system of the water governance in China is systematically designed. The current situation of water governance is comprehensively evaluated and the variation trend of China's water governance in 2020-2050 is forecasted using the hierarchical equal weight method and the target consistency method. The results show that the index of water governance has been increased quickly from below 0. 235 to near 0. 70 since the reform and opening-up. The acceleration period of water governance is from 2010 to 2015, in which the water governance index has increased about 50%. It is expected that the water governance index will exceed 0. 85 by 2020, and the harmonization between economic development and water resources utilization will be realized. The index of water governance will reach 0. 95 by 2030, and the harmonization between economic development and water pollution will be realized. The capacity of water safety support can be significantly improved and the water governance targets can be realized basically. The index of water governance will reach the optimum value of 1 by 2050, and the water resources utilization, water pollution discharge, water disaster loss and water ecology degradation area will be zero growth, fully achieving the harmony between human and water.
The goal of water governance is specified from five dimensions, including resources, economy, sociality, ecology and environment. The evaluation index system of the water governance in China is systematically designed. The current situation of water governance is comprehensively evaluated and the variation trend of China's water governance in 2020-2050 is forecasted using the hierarchical equal weight method and the target consistency method. The results show that the index of water governance has been increased quickly from below 0. 235 to near 0. 70 since the reform and opening-up. The acceleration period of water governance is from 2010 to 2015, in which the water governance index has increased about 50%. It is expected that the water governance index will exceed 0. 85 by 2020, and the harmonization between economic development and water resources utilization will be realized. The index of water governance will reach 0. 95 by 2030, and the harmonization between economic development and water pollution will be realized. The capacity of water safety support can be significantly improved and the water governance targets can be realized basically. The index of water governance will reach the optimum value of 1 by 2050, and the water resources utilization, water pollution discharge, water disaster loss and water ecology degradation area will be zero growth, fully achieving the harmony between human and water.
2015,35(3):11-18, DOI: 10.3880/j.issn.1006-7647.2015.03.003
Abstract:
Fecal Coliform (FC) concentration in surface waters, such as, rivers, lakes, reservoirs and coastal areas, of China was surveyed based on literatures published since 1980s. From the survey, the temporal variation and the spatial distribution of FC concentration is analyzed, and then influencing factors on distribution characteristics of FC are systematically discussed. The results demonstrate that FC concentration is generally high throughout the surface waters in China, which indicates that the waters suffer a severe microbial contamination. Rivers are most severely contaminated among different water bodies while reservoirs are cleanest. The concentration of FC shows significant inter-annual and intra-annual fluctuations, with the concentration in wet seasons being much greater than that in dry seasons. There is no obvious distribution pattern of FC concentration between southern and northern waters, while the FC concentration in eastern areas is obviously greater than that in western areas. The FC concentration in lower reaches of rivers is greater than that in the upper reaches, and the FC concentration near shore is greater than offshore. These indicate that human actions significantly increase the concentration of FC. Rainfall-runoff has a significant impact on the temporal variation and spatial distribution of FC. Besides, many other physical-chemical factors, including organic content, trophic level, salinity, and temperature of water are also responsible for the spatial distribution and temporal variation of concentration of FC.
Fecal Coliform (FC) concentration in surface waters, such as, rivers, lakes, reservoirs and coastal areas, of China was surveyed based on literatures published since 1980s. From the survey, the temporal variation and the spatial distribution of FC concentration is analyzed, and then influencing factors on distribution characteristics of FC are systematically discussed. The results demonstrate that FC concentration is generally high throughout the surface waters in China, which indicates that the waters suffer a severe microbial contamination. Rivers are most severely contaminated among different water bodies while reservoirs are cleanest. The concentration of FC shows significant inter-annual and intra-annual fluctuations, with the concentration in wet seasons being much greater than that in dry seasons. There is no obvious distribution pattern of FC concentration between southern and northern waters, while the FC concentration in eastern areas is obviously greater than that in western areas. The FC concentration in lower reaches of rivers is greater than that in the upper reaches, and the FC concentration near shore is greater than offshore. These indicate that human actions significantly increase the concentration of FC. Rainfall-runoff has a significant impact on the temporal variation and spatial distribution of FC. Besides, many other physical-chemical factors, including organic content, trophic level, salinity, and temperature of water are also responsible for the spatial distribution and temporal variation of concentration of FC.
2017,37(3):1-6, DOI: 10.3880/j.issn.1006-7647.2017.03.001
Abstract:
The development process of research on the water resources carrying capacity in China is systematically summarized, and it can be divided into five stages: the creation of conception, the preliminary study, the gradual improvement, the difficult development, and the innovation era. On the basis of comparison of research methods, the calculation methods of water resources carrying capacity can be divided into three categories: the empirical formula method, comprehensive evaluation method, and system analysis method. The control objective inversion model(COIM)based on simulation and optimization and its applications are introduced. It is pointed out that research on the water resources carrying capacity in the future focuses on: using the empirical formula method to calculate the national water resources carrying capacity and system analysis method for detailed calculation; constructing the calculation model of water resources carrying capacity and forewarning system platform; studying the dynamic carrying capacity of water resources under the changing environment; and considering the current achievements of water resources regulation and the balance development of water resources and economic society.
The development process of research on the water resources carrying capacity in China is systematically summarized, and it can be divided into five stages: the creation of conception, the preliminary study, the gradual improvement, the difficult development, and the innovation era. On the basis of comparison of research methods, the calculation methods of water resources carrying capacity can be divided into three categories: the empirical formula method, comprehensive evaluation method, and system analysis method. The control objective inversion model(COIM)based on simulation and optimization and its applications are introduced. It is pointed out that research on the water resources carrying capacity in the future focuses on: using the empirical formula method to calculate the national water resources carrying capacity and system analysis method for detailed calculation; constructing the calculation model of water resources carrying capacity and forewarning system platform; studying the dynamic carrying capacity of water resources under the changing environment; and considering the current achievements of water resources regulation and the balance development of water resources and economic society.
2016,36(3):1-4, DOI: 10.3880/j.issn.1006-7647.2016.03.001
Abstract:
The characteristics and advantages of the big data method are discussed in this paper. In the method, mathematical formulas are replaced by intensive data in order to precisely describe the temporal and spatial variation of hydrological phenomena or the solution of a differential equation. The reasons why hydrology needs big data and technical support for obtaining hydrological big data are also discussed. The big data method may inspire the innovation of scientific thinking and become a way of solving complex problems in hydrology.
The characteristics and advantages of the big data method are discussed in this paper. In the method, mathematical formulas are replaced by intensive data in order to precisely describe the temporal and spatial variation of hydrological phenomena or the solution of a differential equation. The reasons why hydrology needs big data and technical support for obtaining hydrological big data are also discussed. The big data method may inspire the innovation of scientific thinking and become a way of solving complex problems in hydrology.
Journal information
- Competent unit：
教育部
- Organizers：
河海大学
- Editor-in-chief：
顾冲时
- Address：
南京西康路1号 河海大学《水利水电科技进展》编辑部
- Postcode：
210098
- Phone：
025-83786335
- Email：
jz@hhu.edu.cn
- CN：
32-1439/TV
- ISSN：
1006-7647
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Advances in Science and Technology of Water Resources ® 2025 All Rights ReservedAddress：南京 河海大学《水利水电科技进展》编辑部Postcode：210098Tel：025-83786335
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