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2026,46(4):1-8
DOI: 10.3880/j.issn.1006-7647.2026.04.001
Abstract:
To investigate the effects of restrictive ventilation conditions in a covered vertical shaft on air-pocket motion and geyser characteristics, a combined approach of physical model tests and numerical simulations was employed to systematically examine the influences of shaft diameter, ventilation ratio, external head, and initial air-pocket volume on air-pocket motion and geyser occurrence. The results show that the water-level rise in the shaft during air-pocket release can be divided into an air-pocket-driven stage and a pressure-difference-driven stage, resulting in four typical flow regimes: no geyser, an air-pocket-driven geyser only, a pressure-difference-driven geyser only, and both an air-pocket-driven geyser and a pressure-difference-driven geyser. The air-pocket morphology is jointly influenced by the shaft-to-pipe diameter ratio, ventilation ratio, and air-pocket length. In small-diameter shafts, the air pocket tends to be symmetric and intrudes into the upstream pipe, whereas in larger-diameter shafts, the air pocket exhibits significant asymmetry and remains trapped in the downstream pipe. For small-diameter shafts, the air-pocket head morphology varies non-monotonically with the ventilation ratio: it is approximately symmetric at a ventilation ratio of 0, becomes irregular at ventilation ratios of 0.01 and 0.02, returns to a nearly symmetric shape at ventilation ratios of 0.05 and 0.1, and develops into a sharply asymmetric shape inclined toward the downstream direction at a ventilation ratio of 1 (fully ventilated condition). A larger air-pocket length results in stronger disturbances to the free surface and a higher release position. The rising velocities of both the air-pocket head and the free surface increase significantly with increasing ventilation ratio, external head, and air-pocket length, and decrease with increasing shaft diameter.
To investigate the effects of restrictive ventilation conditions in a covered vertical shaft on air-pocket motion and geyser characteristics, a combined approach of physical model tests and numerical simulations was employed to systematically examine the influences of shaft diameter, ventilation ratio, external head, and initial air-pocket volume on air-pocket motion and geyser occurrence. The results show that the water-level rise in the shaft during air-pocket release can be divided into an air-pocket-driven stage and a pressure-difference-driven stage, resulting in four typical flow regimes: no geyser, an air-pocket-driven geyser only, a pressure-difference-driven geyser only, and both an air-pocket-driven geyser and a pressure-difference-driven geyser. The air-pocket morphology is jointly influenced by the shaft-to-pipe diameter ratio, ventilation ratio, and air-pocket length. In small-diameter shafts, the air pocket tends to be symmetric and intrudes into the upstream pipe, whereas in larger-diameter shafts, the air pocket exhibits significant asymmetry and remains trapped in the downstream pipe. For small-diameter shafts, the air-pocket head morphology varies non-monotonically with the ventilation ratio: it is approximately symmetric at a ventilation ratio of 0, becomes irregular at ventilation ratios of 0.01 and 0.02, returns to a nearly symmetric shape at ventilation ratios of 0.05 and 0.1, and develops into a sharply asymmetric shape inclined toward the downstream direction at a ventilation ratio of 1 (fully ventilated condition). A larger air-pocket length results in stronger disturbances to the free surface and a higher release position. The rising velocities of both the air-pocket head and the free surface increase significantly with increasing ventilation ratio, external head, and air-pocket length, and decrease with increasing shaft diameter.
2026,46(4):9-15, 49
DOI: 10.3880/j.issn.1006-7647.2026.04.002
Abstract:
To investigate the geyser phenomenon characterized by sudden water-air eruptions and localized pressure surges during the filling process of water conveyance systems, an experimental system for transient water-air two-phase flow was designed and constructed. By utilizing the water level difference between upstream and downstream water tanks to indirectly control the base flow, the water-air two-phase transient process during the filling of a water conveyance system equipped with a ventilation shaft was investigated, aiming to explore the triggering mechanisms and dynamic characteristics of geyser phenomena. The experimental results indicate that the geyser transient process considering base flow can be divided into the air pocket impact stage and the eruption stage. During the air pocket impact stage, the air pocket undergoes repeated compression and expansion, accompanied by periodic pressure fluctuations. During the eruption stage, violent water-air interactions occur, a higher base flow rate results in less gas entrainment into the riser, and geyser phenomena are more likely to occur if the entrained gas arrives at the top orifice of the riser later than the free water surface. The geyser phenomena can be classified into four types: multiple-eruption type, no-eruption type, single-eruption type, and damped-eruption type. Additionally, the propagation and superposition of pressure waves induced by air pocket rupture and coalescence during geyser events are identified as significant contributing factors to the unstable pressure fluctuations.
To investigate the geyser phenomenon characterized by sudden water-air eruptions and localized pressure surges during the filling process of water conveyance systems, an experimental system for transient water-air two-phase flow was designed and constructed. By utilizing the water level difference between upstream and downstream water tanks to indirectly control the base flow, the water-air two-phase transient process during the filling of a water conveyance system equipped with a ventilation shaft was investigated, aiming to explore the triggering mechanisms and dynamic characteristics of geyser phenomena. The experimental results indicate that the geyser transient process considering base flow can be divided into the air pocket impact stage and the eruption stage. During the air pocket impact stage, the air pocket undergoes repeated compression and expansion, accompanied by periodic pressure fluctuations. During the eruption stage, violent water-air interactions occur, a higher base flow rate results in less gas entrainment into the riser, and geyser phenomena are more likely to occur if the entrained gas arrives at the top orifice of the riser later than the free water surface. The geyser phenomena can be classified into four types: multiple-eruption type, no-eruption type, single-eruption type, and damped-eruption type. Additionally, the propagation and superposition of pressure waves induced by air pocket rupture and coalescence during geyser events are identified as significant contributing factors to the unstable pressure fluctuations.
2026,46(4):16-20, 36
DOI: 10.3880/j.issn.1006-7647.2026.04.003
Abstract:
The take-off angle of the jet from aeration facilities is a critical hydraulic parameter for accurately calculating the aerated cavity length. The turbulent characteristics of the jet indirectly influence the take-off angle through modifying the diffusion angle, and the underlying physical mechanism is considerably complex. To rigorously account for the effect of flow turbulence on the diffusion angle, the turbulent diffusion angle at the lower jet nappe was quantified based on the theory of two-dimensional free turbulent jets, leading to the derivation of a modified formula for the take-off angle of jet from aeration facilities. A total of 193 test conditions were examined through laboratory experiments conducted in a precision tilting flume, together with engineering applications. The prototype cavity lengths predicted by six alternative take-off angle estimation methods were compared with measured prototype data. Both the model experiments and engineering validations confirm that the proposed correction method for the take-off angle of jet from aeration facilities is reasonable and reliable.
The take-off angle of the jet from aeration facilities is a critical hydraulic parameter for accurately calculating the aerated cavity length. The turbulent characteristics of the jet indirectly influence the take-off angle through modifying the diffusion angle, and the underlying physical mechanism is considerably complex. To rigorously account for the effect of flow turbulence on the diffusion angle, the turbulent diffusion angle at the lower jet nappe was quantified based on the theory of two-dimensional free turbulent jets, leading to the derivation of a modified formula for the take-off angle of jet from aeration facilities. A total of 193 test conditions were examined through laboratory experiments conducted in a precision tilting flume, together with engineering applications. The prototype cavity lengths predicted by six alternative take-off angle estimation methods were compared with measured prototype data. Both the model experiments and engineering validations confirm that the proposed correction method for the take-off angle of jet from aeration facilities is reasonable and reliable.
2026,46(4):21-27
DOI: 10.3880/j.issn.1006-7647.2026.04.004
Abstract:
To address the deterioration of concrete exposed to high-sulfate environments, sulfate wet-dry cycling tests were conducted to systematically investigate the effects of different combined incorporation methods of polyester fiber, basalt fiber, and U-type expansive agent on the sulfate erosion resistance of concrete. By analyzing the deterioration patterns of specimen appearance damage, mass loss, and pore structure evolution, the sulfate erosion resistance of concrete was evaluated, and the synergistic mechanism by which fibers and expansive agent inhibit concrete deterioration was revealed.The results show that the concrete incorporating 0.15% basalt fiber by volume and 4% U-type expansive agent by mass of cementitious materials exhibited the best sulfate erosion resistance. After 50 cycles, the specimens remained intact in appearance, with no paste spalling observed. The mass loss rate was 6.12%, compared with 9.52% for the control group. The proportion of harmless pores decreased by 5.55 percentage points relative to that before the test, while that of the control group decreased by 10.00 percentage points. The synergistic effect of the expansive agent and fibers optimized the pore structure of concrete, thereby improving its impermeability and resistance to sulfate erosion.
To address the deterioration of concrete exposed to high-sulfate environments, sulfate wet-dry cycling tests were conducted to systematically investigate the effects of different combined incorporation methods of polyester fiber, basalt fiber, and U-type expansive agent on the sulfate erosion resistance of concrete. By analyzing the deterioration patterns of specimen appearance damage, mass loss, and pore structure evolution, the sulfate erosion resistance of concrete was evaluated, and the synergistic mechanism by which fibers and expansive agent inhibit concrete deterioration was revealed.The results show that the concrete incorporating 0.15% basalt fiber by volume and 4% U-type expansive agent by mass of cementitious materials exhibited the best sulfate erosion resistance. After 50 cycles, the specimens remained intact in appearance, with no paste spalling observed. The mass loss rate was 6.12%, compared with 9.52% for the control group. The proportion of harmless pores decreased by 5.55 percentage points relative to that before the test, while that of the control group decreased by 10.00 percentage points. The synergistic effect of the expansive agent and fibers optimized the pore structure of concrete, thereby improving its impermeability and resistance to sulfate erosion.
2026,46(4):28-36
DOI: 10.3880/j.issn.1006-7647.2026.04.005
Abstract:
To address the problems of sand boiling and structural deformation failure induced by internal erosion in gap-graded soils under seepage action, erosion tests under different hydraulic gradients were conducted on gap-graded soil specimens with fine particle contents of 20%, 30%, and 40% using an internal seepage erosion apparatus. Based on the discrete element method, the evolution processes of particle loss, contact force chains, and porosity were analyzed, and the mesoscopic erosion characteristics of gap-graded soils were explored. The results show that specimens with higher fine particle contents exhibit higher erosion rates and more intense erosion processes. Under low hydraulic gradients, seepage-induced compaction occurs, resulting in a decrease in porosity, and the variation of porosity exhibits spatial heterogeneity. The fine particle content affects the contact modes among particles within the soil and serves as a triggering factor for particle loss. The combined effects of contact force chain transformation and particle loss lead to erosion-induced failure of the soil.
To address the problems of sand boiling and structural deformation failure induced by internal erosion in gap-graded soils under seepage action, erosion tests under different hydraulic gradients were conducted on gap-graded soil specimens with fine particle contents of 20%, 30%, and 40% using an internal seepage erosion apparatus. Based on the discrete element method, the evolution processes of particle loss, contact force chains, and porosity were analyzed, and the mesoscopic erosion characteristics of gap-graded soils were explored. The results show that specimens with higher fine particle contents exhibit higher erosion rates and more intense erosion processes. Under low hydraulic gradients, seepage-induced compaction occurs, resulting in a decrease in porosity, and the variation of porosity exhibits spatial heterogeneity. The fine particle content affects the contact modes among particles within the soil and serves as a triggering factor for particle loss. The combined effects of contact force chain transformation and particle loss lead to erosion-induced failure of the soil.
2026,46(4):37-44
DOI: 10.3880/j.issn.1006-7647.2026.04.006
Abstract:
To investigate the effects of porosity and pore water saturation on the elastic modulus of concrete at different scales, a multi-scale prediction model for the elastic modulus of wet concrete considering porosity and pore water saturation was established based on the micromechanical inclusion theory. The influence of porosity and pore water saturation on the elastic modulus at multiple scales was analyzed. The results show that the predicted results from the proposed model are in good agreement with multiple sets of experimental results, and the model can accurately predict the elastic modulus of concrete across various scales. The elastic modulus of concrete at the cement paste, mortar, and concrete scales decreases with increasing porosity, and the influence of porosity on the elastic modulus of materials is more pronounced in the dry state than in the saturated state. The elastic modulus of concrete at the cement paste, mortar, and concrete scales increases with increasing pore water saturation, and the higher the porosity, the more significant the increase in elastic modulus with increasing saturation.
To investigate the effects of porosity and pore water saturation on the elastic modulus of concrete at different scales, a multi-scale prediction model for the elastic modulus of wet concrete considering porosity and pore water saturation was established based on the micromechanical inclusion theory. The influence of porosity and pore water saturation on the elastic modulus at multiple scales was analyzed. The results show that the predicted results from the proposed model are in good agreement with multiple sets of experimental results, and the model can accurately predict the elastic modulus of concrete across various scales. The elastic modulus of concrete at the cement paste, mortar, and concrete scales decreases with increasing porosity, and the influence of porosity on the elastic modulus of materials is more pronounced in the dry state than in the saturated state. The elastic modulus of concrete at the cement paste, mortar, and concrete scales increases with increasing pore water saturation, and the higher the porosity, the more significant the increase in elastic modulus with increasing saturation.
2026,46(4):45-49
DOI: 10.3880/j.issn.1006-7647.2026.04.007
Abstract:
To investigate the microscopic mechanism of erosion damage in hydraulic machinery, a qualitative study on the movement characteristics of cavitation bubbles near a single spherical particle was conducted using high-speed photography experiments, based on Weiss’s theorem and Kelvin impulse theory. The Kelvin impulse of cavitation bubbles was quantitatively analyzed with respect to important parameters such as the particle radius and cavitation bubble radius. The results indicate that the theoretical model of Kelvin impulse of cavitation bubbles can effectively predict the movement characteristics of cavitation bubbles under the influence of a single particle. The absolute value of the Kelvin impulse decreases with increasing dimensionless distance between the particle and the cavitation bubble. Compared with linear sinks, virtual point sources contribute more significantly to the Kelvin impulse of cavitation bubbles.
To investigate the microscopic mechanism of erosion damage in hydraulic machinery, a qualitative study on the movement characteristics of cavitation bubbles near a single spherical particle was conducted using high-speed photography experiments, based on Weiss’s theorem and Kelvin impulse theory. The Kelvin impulse of cavitation bubbles was quantitatively analyzed with respect to important parameters such as the particle radius and cavitation bubble radius. The results indicate that the theoretical model of Kelvin impulse of cavitation bubbles can effectively predict the movement characteristics of cavitation bubbles under the influence of a single particle. The absolute value of the Kelvin impulse decreases with increasing dimensionless distance between the particle and the cavitation bubble. Compared with linear sinks, virtual point sources contribute more significantly to the Kelvin impulse of cavitation bubbles.
2026,46(4):50-57
DOI: 10.3880/j.issn.1006-7647.2026.04.008
Abstract:
Based on Landsat remote sensing imagery and in-situ measurements, machine learning methods were used to construct inversion models for total nitrogen (TN) and total phosphorus (TP) mass concentrations across the entire Poyang Lake. Combined with water quality data from the five rivers (the Ganjiang, Fuhe, Xinjiang, Raohe and Xiushui rivers) flowing into the lake, the spatiotemporal distribution characteristics of TN and TP mass concentrations in Poyang Lake from August 2021 to January 2023 were systematically analyzed. The results show that the TN mass concentration inversion model constructed using a back propagation (BP) neural network achieves a good fit ( R 2=0.91), and the TP mass concentration inversion model based on the GA-optimized BP neural network (GA-BP) performs well ( R 2=0.82). The TN and TP mass concentrations in Poyang Lake exhibit strong seasonal variation, and the water quality in the wet season is generally better than that in the dry season. The spatial distribution of TN and TP mass concentrations in the lake area during the wet season shows strong heterogeneity. Areas with high TN and TP mass concentrations in Poyang Lake are mainly concentrated in the central and northeastern parts of the lake area and the entrances of the five rivers flowing into the lake. The extreme drought exacerbated water quality deterioration in Poyang Lake, leading to an increase in the TN and TP mass concentrations across the entire lake.
Based on Landsat remote sensing imagery and in-situ measurements, machine learning methods were used to construct inversion models for total nitrogen (TN) and total phosphorus (TP) mass concentrations across the entire Poyang Lake. Combined with water quality data from the five rivers (the Ganjiang, Fuhe, Xinjiang, Raohe and Xiushui rivers) flowing into the lake, the spatiotemporal distribution characteristics of TN and TP mass concentrations in Poyang Lake from August 2021 to January 2023 were systematically analyzed. The results show that the TN mass concentration inversion model constructed using a back propagation (BP) neural network achieves a good fit ( R 2=0.91), and the TP mass concentration inversion model based on the GA-optimized BP neural network (GA-BP) performs well ( R 2=0.82). The TN and TP mass concentrations in Poyang Lake exhibit strong seasonal variation, and the water quality in the wet season is generally better than that in the dry season. The spatial distribution of TN and TP mass concentrations in the lake area during the wet season shows strong heterogeneity. Areas with high TN and TP mass concentrations in Poyang Lake are mainly concentrated in the central and northeastern parts of the lake area and the entrances of the five rivers flowing into the lake. The extreme drought exacerbated water quality deterioration in Poyang Lake, leading to an increase in the TN and TP mass concentrations across the entire lake.
2026,46(4):58-64, 71
DOI: 10.3880/j.issn.1006-7647.2026.04.009
Abstract:
In order to investigate the effects of different groundwater depths on the yield and water use efficiency of summer maize under rainfed conditions, four treatments with groundwater depths of 0.7, 1.3, 1.8 m and the normal field depth (recorded as D0.7, D1.3, D1.8, and D2.4, respectively) were set up using the groundwater automatic control system. The soil moisture content, rainfall utilization rate, phreatic evaporation, plant height, leaf area index, yield and water consumption during the growth period of summer maize under rainfed conditions were analyzed. The results show that the groundwater depth has significant effects on the average soil water content, rainfall utilization rate, and water use efficiency under rainfed conditions. Compared with D2.4, the average soil moisture content during the whole growth period of summer maize under D0.7, D1.3, and D1.8 treatments increased significantly by 6.9%~28.6%, the rainfall utilization rate decreased by 23.2%, 11.4%, and 2.8%, respectively, and the plant height, leaf area index, and dry matter accumulation decreased by 1.7%~5.2%, 5.8%~13.7%, and 9.4%~19.5%, respectively. Compared with other groundwater depths, the D1.8 treatment can ensure the highest yield and water use efficiency of summer maize in this area.
In order to investigate the effects of different groundwater depths on the yield and water use efficiency of summer maize under rainfed conditions, four treatments with groundwater depths of 0.7, 1.3, 1.8 m and the normal field depth (recorded as D0.7, D1.3, D1.8, and D2.4, respectively) were set up using the groundwater automatic control system. The soil moisture content, rainfall utilization rate, phreatic evaporation, plant height, leaf area index, yield and water consumption during the growth period of summer maize under rainfed conditions were analyzed. The results show that the groundwater depth has significant effects on the average soil water content, rainfall utilization rate, and water use efficiency under rainfed conditions. Compared with D2.4, the average soil moisture content during the whole growth period of summer maize under D0.7, D1.3, and D1.8 treatments increased significantly by 6.9%~28.6%, the rainfall utilization rate decreased by 23.2%, 11.4%, and 2.8%, respectively, and the plant height, leaf area index, and dry matter accumulation decreased by 1.7%~5.2%, 5.8%~13.7%, and 9.4%~19.5%, respectively. Compared with other groundwater depths, the D1.8 treatment can ensure the highest yield and water use efficiency of summer maize in this area.
2026,46(4):65-71
DOI: 10.3880/j.issn.1006-7647.2026.04.010
Abstract:
To quantitatively evaluate water resources security in mining areas, this study takes the X mining area in northern Shaanxi as the research object and constructs an evaluation index system comprising four dimensions (water quality status, water resources quantity, water use efficiency, and ecological sustainability) with a total of 16 secondary indicators, and classifies the risk levels of the indicators. The game theory combination weighting approach is employed to optimize the integration of indicator weights derived from the analytic hierarchy process and the entropy weight method. The combined weights are then incorporated into the TOPSIS method to analyze the multi-year water resources security of the mining area based on the closeness of each indicator to the ideal solution. The results indicate that the comprehensive water resources security level of the mining area from 2017 to 2023 is relatively safe, which is consistent with the actual conditions of the mining area. The primary factors affecting water resources security in the mining area are the surface water quality compliance rate, the wastewater discharge compliance rate of the mining area, and the groundwater pollution index.
To quantitatively evaluate water resources security in mining areas, this study takes the X mining area in northern Shaanxi as the research object and constructs an evaluation index system comprising four dimensions (water quality status, water resources quantity, water use efficiency, and ecological sustainability) with a total of 16 secondary indicators, and classifies the risk levels of the indicators. The game theory combination weighting approach is employed to optimize the integration of indicator weights derived from the analytic hierarchy process and the entropy weight method. The combined weights are then incorporated into the TOPSIS method to analyze the multi-year water resources security of the mining area based on the closeness of each indicator to the ideal solution. The results indicate that the comprehensive water resources security level of the mining area from 2017 to 2023 is relatively safe, which is consistent with the actual conditions of the mining area. The primary factors affecting water resources security in the mining area are the surface water quality compliance rate, the wastewater discharge compliance rate of the mining area, and the groundwater pollution index.
2026,46(4):72-78, 92
DOI: 10.3880/j.issn.1006-7647.2026.04.011
Abstract:
To accurately evaluate the compaction quality of embankment soil materials, a comprehensive assessment method based on multi-source information fusion of roller acceleration data in both the time and frequency domains is proposed. Quantitative relationship models between compaction degree and different indicators, including compaction energy per unit volume, frequency-domain indicator CV, and time-frequency-domain indicator CWT-THD, were established. Utilizing the Dempster-Shafer (D-S) evidence theory as the information fusion framework, the basic probability assignment values of the three indicators and conflicting evidence were optimized through integration with construction practice and Murphy’s rule. The case validation results demonstrate that the proposed method can improve the accuracy of compaction quality evaluation, avoid the limitations of single-indicator assessments, and enable the analysis of spatial uniformity of compaction quality, thereby achieving rapid and accurate evaluation of soil compaction quality.
To accurately evaluate the compaction quality of embankment soil materials, a comprehensive assessment method based on multi-source information fusion of roller acceleration data in both the time and frequency domains is proposed. Quantitative relationship models between compaction degree and different indicators, including compaction energy per unit volume, frequency-domain indicator CV, and time-frequency-domain indicator CWT-THD, were established. Utilizing the Dempster-Shafer (D-S) evidence theory as the information fusion framework, the basic probability assignment values of the three indicators and conflicting evidence were optimized through integration with construction practice and Murphy’s rule. The case validation results demonstrate that the proposed method can improve the accuracy of compaction quality evaluation, avoid the limitations of single-indicator assessments, and enable the analysis of spatial uniformity of compaction quality, thereby achieving rapid and accurate evaluation of soil compaction quality.
2026,46(4):79-86
DOI: 10.3880/j.issn.1006-7647.2026.04.012
Abstract:
To investigate the causes of plane gate jamming in the closing process, a combined approach of physical model experiments and CFD numerical simulations was employed to examine the hydrodynamic characteristics of plane gates during dynamic closure under free-flow conditions. The results show that under the upstream pressure head, plane gates equipped with upstream seals experience significant hydrodynamic thrust forces with minimal contribution from water-induced gravitational forces, rendering gate closure primarily dependent on self-weight. After a period of gate operation, excessive friction coefficient is identified as a significant cause of closing jamming. Under free-flow conditions, the permissible friction coefficient of the plane gate is mainly governed by the gate self-weight, the upstream-downstream head difference, and the effective area subjected to water thrust. Five countermeasures were proposed to facilitate the successful closure of the plane gate: reducing the friction coefficient of supporting materials, increasing counterweights, decreasing the upstream-downstream head difference, reducing the water thrust action area, and appropriately closing the radial gate.
To investigate the causes of plane gate jamming in the closing process, a combined approach of physical model experiments and CFD numerical simulations was employed to examine the hydrodynamic characteristics of plane gates during dynamic closure under free-flow conditions. The results show that under the upstream pressure head, plane gates equipped with upstream seals experience significant hydrodynamic thrust forces with minimal contribution from water-induced gravitational forces, rendering gate closure primarily dependent on self-weight. After a period of gate operation, excessive friction coefficient is identified as a significant cause of closing jamming. Under free-flow conditions, the permissible friction coefficient of the plane gate is mainly governed by the gate self-weight, the upstream-downstream head difference, and the effective area subjected to water thrust. Five countermeasures were proposed to facilitate the successful closure of the plane gate: reducing the friction coefficient of supporting materials, increasing counterweights, decreasing the upstream-downstream head difference, reducing the water thrust action area, and appropriately closing the radial gate.
Numerical simulation of energy characteristics of a large Francis turbine under high-load conditions
2026,46(4):87-92
DOI: 10.3880/j.issn.1006-7647.2026.04.013
Abstract:
To reveal the causes of efficiency degradation in a large Francis turbine under high-load conditions, a numerical simulation investigation was conducted on the mechanism of vortex-induced energy losses. The mean kinetic energy theory was employed to quantify hydraulic losses in each flow passage component, while the rigid vorticity theory was adopted to identify complex vortex structures in the runner and draft tube. The results show that once the discharge exceeds the rated value, the runner and draft tube become the dominant sources of hydraulic loss, accounting for up to 30% and 75% of the total hydraulic loss, respectively. The flow separation-induced vortex at the leading edge of the runner blade merges with the horseshoe vortex at the blade root, producing intense shear flow and significantly increasing energy loss near the leading edge. The velocity gradient between the low-velocity flow near the vortex core of the cylindrical vortex rope in the draft tube and the high-velocity main flow in the outer region significantly enhances turbulent kinetic energy dissipation. The separation vortex in the runner and the cylindrical vortex rope in the draft tube are the primary loss sources under high-load conditions. Their intensities increase with discharge, leading to a substantial reduction in turbine efficiency.
To reveal the causes of efficiency degradation in a large Francis turbine under high-load conditions, a numerical simulation investigation was conducted on the mechanism of vortex-induced energy losses. The mean kinetic energy theory was employed to quantify hydraulic losses in each flow passage component, while the rigid vorticity theory was adopted to identify complex vortex structures in the runner and draft tube. The results show that once the discharge exceeds the rated value, the runner and draft tube become the dominant sources of hydraulic loss, accounting for up to 30% and 75% of the total hydraulic loss, respectively. The flow separation-induced vortex at the leading edge of the runner blade merges with the horseshoe vortex at the blade root, producing intense shear flow and significantly increasing energy loss near the leading edge. The velocity gradient between the low-velocity flow near the vortex core of the cylindrical vortex rope in the draft tube and the high-velocity main flow in the outer region significantly enhances turbulent kinetic energy dissipation. The separation vortex in the runner and the cylindrical vortex rope in the draft tube are the primary loss sources under high-load conditions. Their intensities increase with discharge, leading to a substantial reduction in turbine efficiency.
2026,46(4):93-99, 109
DOI: 10.3880/j.issn.1006-7647.2026.04.014
Abstract:
To address the limitations of traditional outlier detection methods for seepage monitoring data in processing nonlinear and nonstationary water level monitoring data, a hybrid model based on variational mode decomposition (VMD), long short-term memory network (LSTM), and variational autoencoder (VAE) is proposed. In the proposed model, VMD is used to perform multiscale decomposition of the water level time series and obtain intrinsic mode functions with different frequency characteristics. A two-layer LSTM is then employed to capture the temporal dependencies of each modal component. VAE is used for feature compression and reconstruction, and outlier detection is achieved based on the reconstruction error. Case validation results show that the hybrid model can effectively identify isolated outliers and continuous outlier sequences. In scenarios where outliers were randomly added to the test set at proportions of 1%, 2%, and 3%, the model exhibited good detection performance, verifying its effectiveness in outlier detection for seepage monitoring data.
To address the limitations of traditional outlier detection methods for seepage monitoring data in processing nonlinear and nonstationary water level monitoring data, a hybrid model based on variational mode decomposition (VMD), long short-term memory network (LSTM), and variational autoencoder (VAE) is proposed. In the proposed model, VMD is used to perform multiscale decomposition of the water level time series and obtain intrinsic mode functions with different frequency characteristics. A two-layer LSTM is then employed to capture the temporal dependencies of each modal component. VAE is used for feature compression and reconstruction, and outlier detection is achieved based on the reconstruction error. Case validation results show that the hybrid model can effectively identify isolated outliers and continuous outlier sequences. In scenarios where outliers were randomly added to the test set at proportions of 1%, 2%, and 3%, the model exhibited good detection performance, verifying its effectiveness in outlier detection for seepage monitoring data.
2026,46(4):100-109
DOI: 10.3880/j.issn.1006-7647.2026.04.015
Abstract:
Aiming at the problem that hydraulic structures are prone to deterioration such as water stains and calcium precipitation under complex natural environments and operating conditions, thereby complicating surface crack detection, this paper proposes a crack detection model YOLO-SEH integrating a deformable convolutional network (DCNv2) and scaling efficient decoupled head (SEH). An efficient channel attention mechanism is introduced into the model neck to suppress noise interference from complex backgrounds. In the backbone, DCNv2 is adopted to replace the C3 module of YOLOv5, improving the model’s adaptability to irregular crack shapes. SEH is incorporated into the detection head to strengthen the model’s sensitivity and discriminability to crack features. The proposed model was applied to crack detection on sluice and dam images captured by unmanned aerial vehicles (UAVs), achieving mAP@0.5 values of 86.2% and 84.9%, respectively. Ablation experiments show that compared with the YOLOv5 model, the mAP@0.5 of the YOLO-SEH model increased by 3.1 and 4.1 percentage points, the precision increased by 4.8 and 6.6 percentage points, and the recall increased by 3.4 and 4.7 percentage points for the two datasets, respectively. Furthermore, comparative experiments with the Faster R-CNN, SSD300, YOLOv5, YOLOv7, and YOLOv8 models demonstrate that the YOLO-SEH model achieves superior detection performance for crack detection of hydraulic structures.
Aiming at the problem that hydraulic structures are prone to deterioration such as water stains and calcium precipitation under complex natural environments and operating conditions, thereby complicating surface crack detection, this paper proposes a crack detection model YOLO-SEH integrating a deformable convolutional network (DCNv2) and scaling efficient decoupled head (SEH). An efficient channel attention mechanism is introduced into the model neck to suppress noise interference from complex backgrounds. In the backbone, DCNv2 is adopted to replace the C3 module of YOLOv5, improving the model’s adaptability to irregular crack shapes. SEH is incorporated into the detection head to strengthen the model’s sensitivity and discriminability to crack features. The proposed model was applied to crack detection on sluice and dam images captured by unmanned aerial vehicles (UAVs), achieving mAP@0.5 values of 86.2% and 84.9%, respectively. Ablation experiments show that compared with the YOLOv5 model, the mAP@0.5 of the YOLO-SEH model increased by 3.1 and 4.1 percentage points, the precision increased by 4.8 and 6.6 percentage points, and the recall increased by 3.4 and 4.7 percentage points for the two datasets, respectively. Furthermore, comparative experiments with the Faster R-CNN, SSD300, YOLOv5, YOLOv7, and YOLOv8 models demonstrate that the YOLO-SEH model achieves superior detection performance for crack detection of hydraulic structures.
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Abstract:
In order to study the effect of water diversion project operation on the hydrodynamics and water temperature structure of the Hedi reservoir , a three-dimensional hydrodynamic water-temperature coupling model was established based on MIKE3, and the changes of hydrodynamic, water temperature structure and stability of Hedi Reservoir under different scenarios were analyzed by combining the relative water column stability(RWCS). The results show that the high-flow diversion and drainage after the operation of the water diversion project significantly enhance the original hydrodynamic conditions of Hedi Reservoir, and the low operating water level is the most affected by the water diversion due to the small flow in dry years. The hydrodynamic enhancement caused by the inflow of external water will intensify the mixing between water bodies, resulting in a uniform vertical water temperature distribution, and the greater the increase in hydrodynamic force, the greater the damage to the water temperature structure. The change of water temperature structure will cause the change of water intake water temperature, which will have an impact on the irrigation area and downstream ecology. The operation of water diversion project will reduce the stability of thermal stratification of Hedi Reservoir, which will help weaken the water quality stratification formed by water temperature and thermal stratification in summer and autumn.
In order to study the effect of water diversion project operation on the hydrodynamics and water temperature structure of the Hedi reservoir , a three-dimensional hydrodynamic water-temperature coupling model was established based on MIKE3, and the changes of hydrodynamic, water temperature structure and stability of Hedi Reservoir under different scenarios were analyzed by combining the relative water column stability(RWCS). The results show that the high-flow diversion and drainage after the operation of the water diversion project significantly enhance the original hydrodynamic conditions of Hedi Reservoir, and the low operating water level is the most affected by the water diversion due to the small flow in dry years. The hydrodynamic enhancement caused by the inflow of external water will intensify the mixing between water bodies, resulting in a uniform vertical water temperature distribution, and the greater the increase in hydrodynamic force, the greater the damage to the water temperature structure. The change of water temperature structure will cause the change of water intake water temperature, which will have an impact on the irrigation area and downstream ecology. The operation of water diversion project will reduce the stability of thermal stratification of Hedi Reservoir, which will help weaken the water quality stratification formed by water temperature and thermal stratification in summer and autumn.
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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(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.
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(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.
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.
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.
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(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.
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.
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
- Supervisory Authority
教育部
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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
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025-83786335
- E-mail：
jz@hhu.edu.cn
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1006-7647
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Advances in Science and Technology of Water Resources ® 2026 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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