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2026,54(5):1-9
DOI: 10.3876/j.issn.1000-1980.2026.05.001
Abstract:
The predictive capabilities of three nowcasting models (S-PROG, Extrapolation, and ANVIL) for extreme rainfall induced by tropical cyclones were evaluated using the 2017 Hurricane Harvey rainfall event as a case study. The results indicate that the ANVIL model shows the best performance in simulating the spatial distribution of rainfall, but systematically overestimates heavy rainfall intensity; the S-PROG model shows a lag in tracking rainfall intensity variations; and the Extrapolation model achieves the highest stability in short-term (0-2 h) nowcasting, accurately capturing the peak rainfall intensity and its temporal evolution. The fusion of high-resolution meteorological data and multi-source data can significantly enhance model performance, and the combination of radar extrapolation techniques and deep learning algorithms shows great potential.
The predictive capabilities of three nowcasting models (S-PROG, Extrapolation, and ANVIL) for extreme rainfall induced by tropical cyclones were evaluated using the 2017 Hurricane Harvey rainfall event as a case study. The results indicate that the ANVIL model shows the best performance in simulating the spatial distribution of rainfall, but systematically overestimates heavy rainfall intensity; the S-PROG model shows a lag in tracking rainfall intensity variations; and the Extrapolation model achieves the highest stability in short-term (0-2 h) nowcasting, accurately capturing the peak rainfall intensity and its temporal evolution. The fusion of high-resolution meteorological data and multi-source data can significantly enhance model performance, and the combination of radar extrapolation techniques and deep learning algorithms shows great potential.
2026,54(5):10-17, 28
DOI: 10.3876/j.issn.1000-1980.2026.05.002
Abstract:
To reveal the influence of different physical mechanism fusion schemes on the groundwater level prediction accuracy of graph neural network (GCN), six graph convolutional network (GCN) structures with different physical mechanism fusion schemes were designed based on the daily groundwater level data from 114 monitoring stations in the Poyang Lake Basin by comprehensively considering the physical factors such as spatial correlation of groundwater levels, surface water-groundwater connectivity, and rainfall lag effect. The groundwater level prediction accuracies of the six schemes were compared. The results from the Poyang Lake Basin case validation show that the GCN demonstrated excellent overall simulation capability and accuracy when predicting the dynamic changes of groundwater levels; the R 2 of all schemes exceeds 0.9. The scheme fusing one-month-ahead rainfall and surface water-groundwater connectivity attributes achieves the highest accuracy (with an MAE of 0.060 1 m), improving the accuracy by about 6.8% compared with the single distance matrix scheme. Taking rainfall lag into account characterizes better the delayed response of groundwater levels to rainfall; moreover, the connectivity attribute matrix yields better RMSE improvements for phreatic well water-level predictions than for confined wells.
To reveal the influence of different physical mechanism fusion schemes on the groundwater level prediction accuracy of graph neural network (GCN), six graph convolutional network (GCN) structures with different physical mechanism fusion schemes were designed based on the daily groundwater level data from 114 monitoring stations in the Poyang Lake Basin by comprehensively considering the physical factors such as spatial correlation of groundwater levels, surface water-groundwater connectivity, and rainfall lag effect. The groundwater level prediction accuracies of the six schemes were compared. The results from the Poyang Lake Basin case validation show that the GCN demonstrated excellent overall simulation capability and accuracy when predicting the dynamic changes of groundwater levels; the R 2 of all schemes exceeds 0.9. The scheme fusing one-month-ahead rainfall and surface water-groundwater connectivity attributes achieves the highest accuracy (with an MAE of 0.060 1 m), improving the accuracy by about 6.8% compared with the single distance matrix scheme. Taking rainfall lag into account characterizes better the delayed response of groundwater levels to rainfall; moreover, the connectivity attribute matrix yields better RMSE improvements for phreatic well water-level predictions than for confined wells.
2026,54(5):18-28
DOI: 10.3876/j.issn.1000-1980.2026.05.003
Abstract:
To address the problem that traditional interpolation methods are difficult to effectively fuse rain gauge and microwave link rainfall observation data, a collaborative reconstruction framework for rainfall fields based on a stochastic hybrid Whittaker-Shannon algorithm was proposed. By constructing a synthetic rainfall reference field, the two-dimensional precipitation reconstruction performance of single-source interpolation of rain gauges and dual-source fusion of rain gauges and microwave data was systematically compared. At the same time, an image smoothing technique was used to mitigate the problems of excessive noise and lack of smoothness of the stochastic reconstruction method in rainfall field construction. The results show that the spatial reconstruction accuracy of the stochastic hybrid Whittaker-Shannon algorithm is significantly positively correlated with the rain gauge density and microwave link coverage. Moreover, as the number of possible reconstructed fields increases, the accuracy is better; however, when the number of possible reconstructed fields exceeds 20, the overestimation rate of rainfall extent increases to 80%. The 5×5 mean filter can reduce the root mean square error by 60%, which is significantly superior to the median filter and other window scale schemes. Microwave link data have complementary value in enhancing the spatial resolution (up to the 1 km scale) and dynamic representation capability of rainfall fields, providing a scalable and highly promising technical pathway for real-time data assimilation of urban hydrological models under the 5G communication context.
To address the problem that traditional interpolation methods are difficult to effectively fuse rain gauge and microwave link rainfall observation data, a collaborative reconstruction framework for rainfall fields based on a stochastic hybrid Whittaker-Shannon algorithm was proposed. By constructing a synthetic rainfall reference field, the two-dimensional precipitation reconstruction performance of single-source interpolation of rain gauges and dual-source fusion of rain gauges and microwave data was systematically compared. At the same time, an image smoothing technique was used to mitigate the problems of excessive noise and lack of smoothness of the stochastic reconstruction method in rainfall field construction. The results show that the spatial reconstruction accuracy of the stochastic hybrid Whittaker-Shannon algorithm is significantly positively correlated with the rain gauge density and microwave link coverage. Moreover, as the number of possible reconstructed fields increases, the accuracy is better; however, when the number of possible reconstructed fields exceeds 20, the overestimation rate of rainfall extent increases to 80%. The 5×5 mean filter can reduce the root mean square error by 60%, which is significantly superior to the median filter and other window scale schemes. Microwave link data have complementary value in enhancing the spatial resolution (up to the 1 km scale) and dynamic representation capability of rainfall fields, providing a scalable and highly promising technical pathway for real-time data assimilation of urban hydrological models under the 5G communication context.
2026,54(5):29-38, 172
DOI: 10.3876/j.issn.1000-1980.2026.05.004
Abstract:
To meet the needs of hydrological models for high-precision precipitation data, with the humid Tunxi Basin and the semi-humid Zijingguan Basin as the study areas, a multi-source precipitation merging algorithm based on external drift kriging was constructed to merge the measured precipitation data at stations and the IMERG satellite precipitation data, generating merged precipitation data with high precision and high spatiotemporal resolution. The WRF-Hydro hydrological model was driven by the merged precipitation data to conduct runoff simulations in the study areas, and its applicability in flood forecasting for small and medium-sized rivers was evaluated. The results show that taking the measured precipitation data at stations as the benchmark, the satellite precipitation data exhibits a serious underestimation of precipitation intensity in the Zijingguan Basin, and the evaluation indicators of the merged precipitation data are better than those of the original IMERG satellite precipitation data. Furthermore, the WRF-Hydro model driven by the merged precipitation data can better simulate the flood process than that driven by the IMERG satellite precipitation data, and the model shows stronger applicability in the humid basin than in the semi-humid basin.
To meet the needs of hydrological models for high-precision precipitation data, with the humid Tunxi Basin and the semi-humid Zijingguan Basin as the study areas, a multi-source precipitation merging algorithm based on external drift kriging was constructed to merge the measured precipitation data at stations and the IMERG satellite precipitation data, generating merged precipitation data with high precision and high spatiotemporal resolution. The WRF-Hydro hydrological model was driven by the merged precipitation data to conduct runoff simulations in the study areas, and its applicability in flood forecasting for small and medium-sized rivers was evaluated. The results show that taking the measured precipitation data at stations as the benchmark, the satellite precipitation data exhibits a serious underestimation of precipitation intensity in the Zijingguan Basin, and the evaluation indicators of the merged precipitation data are better than those of the original IMERG satellite precipitation data. Furthermore, the WRF-Hydro model driven by the merged precipitation data can better simulate the flood process than that driven by the IMERG satellite precipitation data, and the model shows stronger applicability in the humid basin than in the semi-humid basin.
2026,54(5):39-48, 90
DOI: 10.3876/j.issn.1000-1980.2026.05.005
Abstract:
Based on the soil temperature and meteorological observation data from the Wudaogou Experimental Station in the Huaibei Plain from 2000 to 2024, the correlation function feature (CFF) method was adopted to systematically analyze the lag effects of meteorological factors, such as air temperature and air pressure, at different soil depths (10, 20, 40, 80, 160, and 320 cm). Using the lag-processed meteorological factors at each depth as inputs, the convolutional neural network (CNN), long short-term memory (LSTM), and CNN-LSTM models were driven to simulate the evolution processes of soil temperature at the six depths, and the applicability and accuracy of the three machine learning models at different depths were evaluated. The results indicate that the optimal lag time of meteorological factors increases with the increase of soil depth. The lag time of shallow soil (10-20 cm) is the shortest (0-3 d); the lag time of middle soil (40-80 cm) is 8-29 d; the lag time of deep soil (160-320 cm) extends to 44-89 d. The simulation performance of the three machine learning models exhibits clear stratified differences at different depths, with the shallow layer generally outperforming the deep layer. The CNN-LSTM model demonstrates higher accuracy and stability at all depths, and its coefficient of determination ( R 2) is generally maintained above 0.94, outperforming the single models. In the deep soil of 320 cm, the R 2 of the CNN-LSTM model is 0.941, which improves by 17% compared with the LSTM model and 45% compared with the CNN model. This reflects the advantages of coupling convolutional feature extraction with temporal memory capability.
Based on the soil temperature and meteorological observation data from the Wudaogou Experimental Station in the Huaibei Plain from 2000 to 2024, the correlation function feature (CFF) method was adopted to systematically analyze the lag effects of meteorological factors, such as air temperature and air pressure, at different soil depths (10, 20, 40, 80, 160, and 320 cm). Using the lag-processed meteorological factors at each depth as inputs, the convolutional neural network (CNN), long short-term memory (LSTM), and CNN-LSTM models were driven to simulate the evolution processes of soil temperature at the six depths, and the applicability and accuracy of the three machine learning models at different depths were evaluated. The results indicate that the optimal lag time of meteorological factors increases with the increase of soil depth. The lag time of shallow soil (10-20 cm) is the shortest (0-3 d); the lag time of middle soil (40-80 cm) is 8-29 d; the lag time of deep soil (160-320 cm) extends to 44-89 d. The simulation performance of the three machine learning models exhibits clear stratified differences at different depths, with the shallow layer generally outperforming the deep layer. The CNN-LSTM model demonstrates higher accuracy and stability at all depths, and its coefficient of determination ( R 2) is generally maintained above 0.94, outperforming the single models. In the deep soil of 320 cm, the R 2 of the CNN-LSTM model is 0.941, which improves by 17% compared with the LSTM model and 45% compared with the CNN model. This reflects the advantages of coupling convolutional feature extraction with temporal memory capability.
2026,54(5):49-59
DOI: 10.3876/j.issn.1000-1980.2026.05.006
Abstract:
To address the problems of low image contrast, color distortion, and blurred details caused by turbid underwater environments, an underwater image restoration network based on multi-channel polarization and a dual-branch Transformer was proposed. A polarization feature adaptive fusion module based on the Stokes vector was used to extract the physical polarization features of water. A spatial-polarization dual-branch architecture was constructed, and a dynamic gating mechanism was utilized to adaptively fuse multi-source information, such as polarization intensity, degree of polarization, and polarization angle, with spatial features, overcoming the limitation of incomplete representation by single-modality information. An encoder-decoder structure integrating multi-scale feature interaction, channel attention, and multi-scale spatial Transformer modules was adopted for the network backbone to enhance the capabilities of degradation representation and global detail restoration. The experimental results show that this method has significant advantages in structure restoration, detail preservation, and color correction (SSIM: 0.854 0, PSNR: 32.93 dB, perceptual metric LPIPS: 0.363 3), and can significantly improve the clarity, contrast, and color fidelity of the restored images.
To address the problems of low image contrast, color distortion, and blurred details caused by turbid underwater environments, an underwater image restoration network based on multi-channel polarization and a dual-branch Transformer was proposed. A polarization feature adaptive fusion module based on the Stokes vector was used to extract the physical polarization features of water. A spatial-polarization dual-branch architecture was constructed, and a dynamic gating mechanism was utilized to adaptively fuse multi-source information, such as polarization intensity, degree of polarization, and polarization angle, with spatial features, overcoming the limitation of incomplete representation by single-modality information. An encoder-decoder structure integrating multi-scale feature interaction, channel attention, and multi-scale spatial Transformer modules was adopted for the network backbone to enhance the capabilities of degradation representation and global detail restoration. The experimental results show that this method has significant advantages in structure restoration, detail preservation, and color correction (SSIM: 0.854 0, PSNR: 32.93 dB, perceptual metric LPIPS: 0.363 3), and can significantly improve the clarity, contrast, and color fidelity of the restored images.
2026,54(5):60-68
DOI: 10.3876/j.issn.1000-1980.2026.05.007
Abstract:
To investigate the impact of cavitation on the unsteady flow and energy loss characteristics in a water-jet pump, the unsteady calculations of its internal cavitating flow field were carried out based on the unsteady Reynolds-averaged Navier-Stokes (URANS) equations, adopting the FBM-CC turbulence model and ZGB cavitation model. The unsteady flow and energy loss characteristics under typical cavitation conditions were analyzed by combining the boundary vorticity flux diagnosis and entropy generation theory. The results show: The adopted numerical simulation method has good accuracy for the calculation of cavitating flow in the water-jet pump; as the net positive suction head decreases, cavitation develops from clearance cavitation to wedge-shaped cavitation; under the deep cavitation condition (the net positive suction head is 11.32 m), cavitation covers almost the entire blade suction surface, inducing the fracture of the tip leakage vortex and the formation of cavitation-induced vortices that block the flow passage; a strong adverse pressure gradient exists at the cavitation end, and streamline distortion and flow separation appear at the tip trailing edge; in the initial stage of cavitation, the energy loss is dominated by wall friction; under the deep cavitation condition, turbulent dissipation becomes the main contributor, and the entropy generation of turbulent dissipation increases by 5% compared to the initial cavitation; at this time, the flow separation of the wake and the vortex caused by cavitation become the main sources of energy loss.
To investigate the impact of cavitation on the unsteady flow and energy loss characteristics in a water-jet pump, the unsteady calculations of its internal cavitating flow field were carried out based on the unsteady Reynolds-averaged Navier-Stokes (URANS) equations, adopting the FBM-CC turbulence model and ZGB cavitation model. The unsteady flow and energy loss characteristics under typical cavitation conditions were analyzed by combining the boundary vorticity flux diagnosis and entropy generation theory. The results show: The adopted numerical simulation method has good accuracy for the calculation of cavitating flow in the water-jet pump; as the net positive suction head decreases, cavitation develops from clearance cavitation to wedge-shaped cavitation; under the deep cavitation condition (the net positive suction head is 11.32 m), cavitation covers almost the entire blade suction surface, inducing the fracture of the tip leakage vortex and the formation of cavitation-induced vortices that block the flow passage; a strong adverse pressure gradient exists at the cavitation end, and streamline distortion and flow separation appear at the tip trailing edge; in the initial stage of cavitation, the energy loss is dominated by wall friction; under the deep cavitation condition, turbulent dissipation becomes the main contributor, and the entropy generation of turbulent dissipation increases by 5% compared to the initial cavitation; at this time, the flow separation of the wake and the vortex caused by cavitation become the main sources of energy loss.
2026,54(5):69-78
DOI: 10.3876/j.issn.1000-1980.2026.05.008
Abstract:
To reveal the impacts of changes in flow and sediment on channel erosion and deposition in the lower Yellow River channel and to improve the efficiency of engineering regulation of flow and sediment for de-siltation, the formula for channel erosion and deposition in the lower reach by Chien Ning et al. was revised using flow and sediment data based on the “more incoming, more discharging” sediment transport characteristic of the Yellow River and the river sediment transport theory. Consequently, an erosion and deposition formula and a comprehensive incoming sediment coefficient with a clear physical meaning, which could more comprehensively reflect the effects of conditions such as flow and sediment volume and suspended sediment gradation, were obtained. The results show that the revised formula has a unified parameter and coefficient, and the simulated erosion and deposition intensities in both the full period and individual sub-periods have high accuracy; furthermore, it can be used to study the comprehensive flow-sediment relationship and erosion and deposition regulation mode in the lower Yellow River after reservoir sediment trapping and sediment gradation alteration; altering sediment gradation through reservoir sediment trapping and regulation can significantly affect the sediment transport capacity of the downstream channel; the optimal operation of “trapping coarse sediment and discharging fine sediment” for flood control and de-siltation reservoirs can largely reduce the deposition in the downstream channel, which is of great significance for maintaining the long-term stability of the downstream channel and ensuring the flood control capacity of the reservoirs.
To reveal the impacts of changes in flow and sediment on channel erosion and deposition in the lower Yellow River channel and to improve the efficiency of engineering regulation of flow and sediment for de-siltation, the formula for channel erosion and deposition in the lower reach by Chien Ning et al. was revised using flow and sediment data based on the “more incoming, more discharging” sediment transport characteristic of the Yellow River and the river sediment transport theory. Consequently, an erosion and deposition formula and a comprehensive incoming sediment coefficient with a clear physical meaning, which could more comprehensively reflect the effects of conditions such as flow and sediment volume and suspended sediment gradation, were obtained. The results show that the revised formula has a unified parameter and coefficient, and the simulated erosion and deposition intensities in both the full period and individual sub-periods have high accuracy; furthermore, it can be used to study the comprehensive flow-sediment relationship and erosion and deposition regulation mode in the lower Yellow River after reservoir sediment trapping and sediment gradation alteration; altering sediment gradation through reservoir sediment trapping and regulation can significantly affect the sediment transport capacity of the downstream channel; the optimal operation of “trapping coarse sediment and discharging fine sediment” for flood control and de-siltation reservoirs can largely reduce the deposition in the downstream channel, which is of great significance for maintaining the long-term stability of the downstream channel and ensuring the flood control capacity of the reservoirs.
2026,54(5):79-90
DOI: 10.3876/j.issn.1000-1980.2026.05.009
Abstract:
To address problems such as insufficient multi-source data integration, lacking system-level association analysis, and weak decision interpretability in current decision-making of river regulation schemes, an intelligent decision-making method for river regulation schemes via collaboration of knowledge graph and large language model was proposed. In this method, a knowledge graph for river regulation was constructed by integrating multi-source data such as river channels, sluice operating conditions, and dyke-cluster topology. A two-stage classification model was designed (Stage 1 modeled physical features and engineering ratio parameters based on random forests; Stage 2 extracted topological relationships from the knowledge graph and utilized the Node2Vec algorithm to generate 64-dimensional graph embedding features input into a logistic regression model for optimizing decision boundary). A generative evaluation engine based on DeepSeek-R1 was developed, which combined domain-knowledge-enhanced prompt learning to generate interpretable reasoning chains through multi-step reasoning for scheme feasibility assessment and improvement recommendation generation. The proposed method was validated through multi-label classification performance comparison and ablation experiments. Verification results of 228 river channels in Nansha District, Guangzhou indicate that this method can effectively alleviate the problems of insufficient multi-source data integration, missing system-level association analysis, and weak interpretability of decision-making process in traditional methods. Its F1 score (the harmonic mean of precision and recall) reaches 0.853, and the accuracy reaches 0.921, indicating that its overall performance is superior to that of the baseline models considered. Both the topological embedding and the domain-knowledge-enhanced multi-step reasoning mechanism can effectively improve method performance. The proposed method achieves the highest F1 score and the lowest Hamming loss, verifying the effectiveness of each key module.
To address problems such as insufficient multi-source data integration, lacking system-level association analysis, and weak decision interpretability in current decision-making of river regulation schemes, an intelligent decision-making method for river regulation schemes via collaboration of knowledge graph and large language model was proposed. In this method, a knowledge graph for river regulation was constructed by integrating multi-source data such as river channels, sluice operating conditions, and dyke-cluster topology. A two-stage classification model was designed (Stage 1 modeled physical features and engineering ratio parameters based on random forests; Stage 2 extracted topological relationships from the knowledge graph and utilized the Node2Vec algorithm to generate 64-dimensional graph embedding features input into a logistic regression model for optimizing decision boundary). A generative evaluation engine based on DeepSeek-R1 was developed, which combined domain-knowledge-enhanced prompt learning to generate interpretable reasoning chains through multi-step reasoning for scheme feasibility assessment and improvement recommendation generation. The proposed method was validated through multi-label classification performance comparison and ablation experiments. Verification results of 228 river channels in Nansha District, Guangzhou indicate that this method can effectively alleviate the problems of insufficient multi-source data integration, missing system-level association analysis, and weak interpretability of decision-making process in traditional methods. Its F1 score (the harmonic mean of precision and recall) reaches 0.853, and the accuracy reaches 0.921, indicating that its overall performance is superior to that of the baseline models considered. Both the topological embedding and the domain-knowledge-enhanced multi-step reasoning mechanism can effectively improve method performance. The proposed method achieves the highest F1 score and the lowest Hamming loss, verifying the effectiveness of each key module.
2026,54(5):91-98
DOI: 10.3876/j.issn.1000-1980.2026.05.010
Abstract:
To address the issue of simulation bias in hydrological models caused by insufficient modeling or unmodeled behaviors under complex environmental conditions, an inflow forecasting method for hydropower stations based on machine learning and Bayesian model averaging (BMA) was proposed. Based on the Hydromad model, the inflow and residual sequences were calculated; three machine learning models, namely random forest (RF) model, XGBoost model, and support vector regression (SVR) model, were used to capture the nonlinear characteristics of the residuals. Subsequently, the multi-model prediction results were fused via BMA to achieve post-processing error correction and uncertainty assessment of the simulation errors. The case study results of Liyuan Hydropower Station on Jinsha River indicate that the proposed method can significantly improve the fitting accuracy of the Hydromad model in peak flood responses and the rising and falling water stages. After correction, indicators of inflow prediction such as NSE and KGE are significantly improved; the water volume bias is effectively controlled; the overall prediction accuracy is obviously improved. This method can provide more scientific technical support for inflow forecasting and operational decision-making of hydropower stations.
To address the issue of simulation bias in hydrological models caused by insufficient modeling or unmodeled behaviors under complex environmental conditions, an inflow forecasting method for hydropower stations based on machine learning and Bayesian model averaging (BMA) was proposed. Based on the Hydromad model, the inflow and residual sequences were calculated; three machine learning models, namely random forest (RF) model, XGBoost model, and support vector regression (SVR) model, were used to capture the nonlinear characteristics of the residuals. Subsequently, the multi-model prediction results were fused via BMA to achieve post-processing error correction and uncertainty assessment of the simulation errors. The case study results of Liyuan Hydropower Station on Jinsha River indicate that the proposed method can significantly improve the fitting accuracy of the Hydromad model in peak flood responses and the rising and falling water stages. After correction, indicators of inflow prediction such as NSE and KGE are significantly improved; the water volume bias is effectively controlled; the overall prediction accuracy is obviously improved. This method can provide more scientific technical support for inflow forecasting and operational decision-making of hydropower stations.
2026,54(5):99-105
DOI: 10.3876/j.issn.1000-1980.2026.05.011
Abstract:
There is high salt content in soil in the coastal tidal flat reclamation area of Jiangsu Province. In order to make rational use of rainfall and adopt underground pipe drainage facilities to improve the desalinization of soil in the tidal flat, an underground pipe drainage experiment was carried out in a typical area. By conducting tests under different underground pipe spacings, the analysis of soil’s salt content at different depths (0-80 cm) in the experimental area was carried out to study the dynamic change pattern of salinity in the soil profile. The results show that in the control area without underground pipes, the salt content of the soil at different depths shows an upward trend, while in the area with underground pipes, the salt content of the soil at different depths shows a general downward trend. Under different underground pipe spacing, the variation of the soil’s salt content at different depths is roughly the same, but the amplitude is different. A smaller underground pipe spacing indicates a more obvious soil desalinization effect; when the underground pipe spacing is the same, the soil desalinization effect will weaken as the depth of the soil layer increases.
There is high salt content in soil in the coastal tidal flat reclamation area of Jiangsu Province. In order to make rational use of rainfall and adopt underground pipe drainage facilities to improve the desalinization of soil in the tidal flat, an underground pipe drainage experiment was carried out in a typical area. By conducting tests under different underground pipe spacings, the analysis of soil’s salt content at different depths (0-80 cm) in the experimental area was carried out to study the dynamic change pattern of salinity in the soil profile. The results show that in the control area without underground pipes, the salt content of the soil at different depths shows an upward trend, while in the area with underground pipes, the salt content of the soil at different depths shows a general downward trend. Under different underground pipe spacing, the variation of the soil’s salt content at different depths is roughly the same, but the amplitude is different. A smaller underground pipe spacing indicates a more obvious soil desalinization effect; when the underground pipe spacing is the same, the soil desalinization effect will weaken as the depth of the soil layer increases.
2026,54(5):106-113, 163
DOI: 10.3876/j.issn.1000-1980.2026.05.012
Abstract:
To reconstruct the hydrodynamics of the Shabei River Network in the Changhu water system of Jingzhou under limited water diversion, a joint gate group operation method based on gate regulation response characteristics and phased single-objective optimization was proposed. A one-dimensional hydrodynamic model was established to conduct sensitivity analysis of single-gate regulation, and key gates and their effective opening ranges were identified. Based on this, a joint gate group operation optimization model was constructed to systematically analyze and determine the optimal operation scheme. The results indicate that different gates have varying impacts on the hydrodynamics of different channels; single-gate regulation can hardly achieve coordinated improvement of hydrodynamics in both main and branch canals. Under the condition of an average daily water diversion flow of 5 m3/s, the optimal operation scheme increased the flow velocity in stagnant flow zones by over 25%, increased the average flow velocity of the river network by 14.72%-22.44%, and maintained the flow velocity above 0.1 m/s in main canals during the regulation process, effectively reconstructing the hydrodynamics of the study area and ensuring the water diversion and drainage functions of the river network.
To reconstruct the hydrodynamics of the Shabei River Network in the Changhu water system of Jingzhou under limited water diversion, a joint gate group operation method based on gate regulation response characteristics and phased single-objective optimization was proposed. A one-dimensional hydrodynamic model was established to conduct sensitivity analysis of single-gate regulation, and key gates and their effective opening ranges were identified. Based on this, a joint gate group operation optimization model was constructed to systematically analyze and determine the optimal operation scheme. The results indicate that different gates have varying impacts on the hydrodynamics of different channels; single-gate regulation can hardly achieve coordinated improvement of hydrodynamics in both main and branch canals. Under the condition of an average daily water diversion flow of 5 m3/s, the optimal operation scheme increased the flow velocity in stagnant flow zones by over 25%, increased the average flow velocity of the river network by 14.72%-22.44%, and maintained the flow velocity above 0.1 m/s in main canals during the regulation process, effectively reconstructing the hydrodynamics of the study area and ensuring the water diversion and drainage functions of the river network.
2026,54(5):114-120
DOI: 10.3876/j.issn.1000-1980.2026.05.013
Abstract:
For the reinforcement problem of three-dimensional rock slopes under the Hoek-Brown criterion, a non-discrete multi-objective optimization design method for anti-slide piles combining mechanical analysis and the response surface method was proposed. The stability model for three-dimensional pile-reinforced slopes was established using the upper bound limit analysis method. Artificial neural networks were adopted to establish the response surface model between the safety factor and the design and strength parameters to quickly obtain a large number of safety factor samples required for reliability evaluation. Furthermore, taking the reinforcement cost and slope reliability as optimization objectives, the Pareto front was directly solved by non-discrete point selection in the continuous design variable space. The case analysis results show that, compared with the discrete design method, the non-discrete design can more comprehensively explore the feasible design domain and obtain more optimized design schemes; under the minimum cost and knee point decision strategies, the costs of the non-discrete design decrease by approximately 18% and 14%, respectively; the pile spacing, pile diameter, and pile position all exhibit significant nonlinear effects on the slope reliability index, and the reinforcement effect is optimal when the piles are placed in the upper part of the slope face.
For the reinforcement problem of three-dimensional rock slopes under the Hoek-Brown criterion, a non-discrete multi-objective optimization design method for anti-slide piles combining mechanical analysis and the response surface method was proposed. The stability model for three-dimensional pile-reinforced slopes was established using the upper bound limit analysis method. Artificial neural networks were adopted to establish the response surface model between the safety factor and the design and strength parameters to quickly obtain a large number of safety factor samples required for reliability evaluation. Furthermore, taking the reinforcement cost and slope reliability as optimization objectives, the Pareto front was directly solved by non-discrete point selection in the continuous design variable space. The case analysis results show that, compared with the discrete design method, the non-discrete design can more comprehensively explore the feasible design domain and obtain more optimized design schemes; under the minimum cost and knee point decision strategies, the costs of the non-discrete design decrease by approximately 18% and 14%, respectively; the pile spacing, pile diameter, and pile position all exhibit significant nonlinear effects on the slope reliability index, and the reinforcement effect is optimal when the piles are placed in the upper part of the slope face.
2026,54(5):121-128
DOI: 10.3876/j.issn.1000-1980.2026.05.014
Abstract:
To investigate the crack resistance of typical asphalt mixtures under salt erosion and dynamic water conditions, direct tensile tests combined with the digital image correlation (DIC) method were conducted to examine the tensile strength evolution and principal strain field development of AH-70, SBS-modified, and rubber-modified asphalt mixtures. The results show that all the mixtures exhibited ductile failure characteristics, with cracks mostly initiating at the binder-aggregate interface and propagating along the strain concentration zones. Dynamic water cycling markedly induced interfacial stripping and moisture damage in the AH-70 asphalt mixture, whereas static saline dry-wet cycling further exacerbated pore expansion. After 20 d of dry-wet cycling in a 20% salt solution, the tensile strength and strain energy density of the AH-70 asphalt mixture decreased by 41.6% and 57.8%, respectively, and these values decreased by 56.1% and 69.4% after dynamic water cycling. In contrast, the SBS- and rubber-modified asphalt mixtures showed superior structural stability and durability. High salinity and dry-wet cycling jointly weakened the toughness of the asphalt mixtures. However, owing to its excellent viscoelasticity, rubber-modified asphalt retained a higher residual strength and energy absorption capacity, exhibiting notable advantages in crack and stripping resistance.
To investigate the crack resistance of typical asphalt mixtures under salt erosion and dynamic water conditions, direct tensile tests combined with the digital image correlation (DIC) method were conducted to examine the tensile strength evolution and principal strain field development of AH-70, SBS-modified, and rubber-modified asphalt mixtures. The results show that all the mixtures exhibited ductile failure characteristics, with cracks mostly initiating at the binder-aggregate interface and propagating along the strain concentration zones. Dynamic water cycling markedly induced interfacial stripping and moisture damage in the AH-70 asphalt mixture, whereas static saline dry-wet cycling further exacerbated pore expansion. After 20 d of dry-wet cycling in a 20% salt solution, the tensile strength and strain energy density of the AH-70 asphalt mixture decreased by 41.6% and 57.8%, respectively, and these values decreased by 56.1% and 69.4% after dynamic water cycling. In contrast, the SBS- and rubber-modified asphalt mixtures showed superior structural stability and durability. High salinity and dry-wet cycling jointly weakened the toughness of the asphalt mixtures. However, owing to its excellent viscoelasticity, rubber-modified asphalt retained a higher residual strength and energy absorption capacity, exhibiting notable advantages in crack and stripping resistance.
2026,54(5):129-137
DOI: 10.3876/j.issn.1000-1980.2026.05.015
Abstract:
To address the problems that the anti-disintegration property of surficial clayey soils is prone to deterioration under meteorological factors such as rainfall and drought, and traditional improvement materials such as cement and lime have defects such as high brittleness and irreversibility, the clayey soil in Nanjing area was taken as the research object to prepare improved soil samples with different lignin derivative contents and conduct disintegration tests. Combined with scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS), the macroscopic and microscopic mechanisms of the anti-disintegration properties of clayey soils improved by lignin derivatives were revealed. The results show that the disintegration process of improved clayey soils is divided into three stages: initial saturation, rapid disintegration, and slow disintegration; the 1% content has the optimal effect, with the initial saturation stage extended to 9 min, the complete disintegration time doubled compared with that of untreated soil, and the average disintegration rate reduced by 20.13%; lignin derivatives form a film-like structure on particle surfaces to wrap and connect particles, reduce pore connectivity, introduce Ca2+ to enhance cementation, and inhibit water infiltration; when the lignin derivative content is too high, the films aggregate, interparticle connections weaken, and the anti-disintegration performance decreases.
To address the problems that the anti-disintegration property of surficial clayey soils is prone to deterioration under meteorological factors such as rainfall and drought, and traditional improvement materials such as cement and lime have defects such as high brittleness and irreversibility, the clayey soil in Nanjing area was taken as the research object to prepare improved soil samples with different lignin derivative contents and conduct disintegration tests. Combined with scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS), the macroscopic and microscopic mechanisms of the anti-disintegration properties of clayey soils improved by lignin derivatives were revealed. The results show that the disintegration process of improved clayey soils is divided into three stages: initial saturation, rapid disintegration, and slow disintegration; the 1% content has the optimal effect, with the initial saturation stage extended to 9 min, the complete disintegration time doubled compared with that of untreated soil, and the average disintegration rate reduced by 20.13%; lignin derivatives form a film-like structure on particle surfaces to wrap and connect particles, reduce pore connectivity, introduce Ca2+ to enhance cementation, and inhibit water infiltration; when the lignin derivative content is too high, the films aggregate, interparticle connections weaken, and the anti-disintegration performance decreases.
2026,54(5):138-145
DOI: 10.3876/j.issn.1000-1980.2026.05.016
Abstract:
To address the problems of low computational efficiency and difficulties in multi-objective optimization during the inversion of constitutive parameters of the Duncan E-B model for gravel pile composite foundations, an intelligent inversion method integrating a radial basis function (RBF) surrogate model and a multi-objective rime (MORIME) optimization algorithm was proposed. In this method, Latin hypercube sampling was adopted to construct the parameter sample set; an RBF surrogate model was established to replace finite element computations; the MORIME optimization algorithm with a local exploitation strategy was introduced to achieve rapid inversion. A single-pile static load test at a pumped storage power station was taken as an example to verify the parameter inversion of the Duncan E-B model for the gravel pile and the surrounding soil. The results show that the inversion method has high inversion accuracy; the coefficients of determination of curves at different monitoring points obtained by substituting the optimal inverted parameters back into the finite element computations are all above 0.99; the dual-mode local exploitation strategy can significantly optimize key objectives and reduce the number of iterations for convergence. The SHAP sensitivity analysis further shows that the surrounding soil parameters K and K b have a significant influence on the pile-top displacement and the soil stress near the pile top.
To address the problems of low computational efficiency and difficulties in multi-objective optimization during the inversion of constitutive parameters of the Duncan E-B model for gravel pile composite foundations, an intelligent inversion method integrating a radial basis function (RBF) surrogate model and a multi-objective rime (MORIME) optimization algorithm was proposed. In this method, Latin hypercube sampling was adopted to construct the parameter sample set; an RBF surrogate model was established to replace finite element computations; the MORIME optimization algorithm with a local exploitation strategy was introduced to achieve rapid inversion. A single-pile static load test at a pumped storage power station was taken as an example to verify the parameter inversion of the Duncan E-B model for the gravel pile and the surrounding soil. The results show that the inversion method has high inversion accuracy; the coefficients of determination of curves at different monitoring points obtained by substituting the optimal inverted parameters back into the finite element computations are all above 0.99; the dual-mode local exploitation strategy can significantly optimize key objectives and reduce the number of iterations for convergence. The SHAP sensitivity analysis further shows that the surrounding soil parameters K and K b have a significant influence on the pile-top displacement and the soil stress near the pile top.
2026,54(5):146-154
DOI: 10.3876/j.issn.1000-1980.2026.05.017
Abstract:
To investigate the influence of general scour on the bearing performance of the anchorage of Xiamen Liuwudian Navigation Channel Bridge, scaled model tests and finite element numerical simulations were conducted. Homogeneous quartz sand was adopted to simulate the soil surrounding the anchorage. Under working conditions with different scour depths, scaled model tests including unidirectional loading, unidirectional single-stage loading-unloading and unidirectional step-increasing cyclic loading-unloading were performed to obtain the load-displacement curves of the anchorage. The finite element modeling method was validated against the test data, and a three-dimensional numerical model of the prototype anchorage, considering actual soil stratification and replacement reinforcement, was established. The scaled model test results reveal that the ultimate bearing capacity of the anchorage decreases by approximately 14.3% with each additional scour depth of 0.33 H ( H denotes the embedded depth of the anchorage), and different loading modes exert slight effects on the ultimate bearing capacity. Numerical simulation results indicate that at the prototype site, the ultimate bearing capacity declines at a rate of about 10.3% when the scour depth increases stepwise by 0.2 H . Although slight numerical differences exist between simulation and test results, their overall variation trends are consistent. As scour intensifies, the failure mode of the anchorage gradually transitions from overturning-dominated to global sliding. Among the constitutive parameters of surrounding soil, the internal friction angle exerts the most significant influence on the ultimate bearing capacity, followed by cohesion, whereas the elastic modulus has a relatively minor effect.
To investigate the influence of general scour on the bearing performance of the anchorage of Xiamen Liuwudian Navigation Channel Bridge, scaled model tests and finite element numerical simulations were conducted. Homogeneous quartz sand was adopted to simulate the soil surrounding the anchorage. Under working conditions with different scour depths, scaled model tests including unidirectional loading, unidirectional single-stage loading-unloading and unidirectional step-increasing cyclic loading-unloading were performed to obtain the load-displacement curves of the anchorage. The finite element modeling method was validated against the test data, and a three-dimensional numerical model of the prototype anchorage, considering actual soil stratification and replacement reinforcement, was established. The scaled model test results reveal that the ultimate bearing capacity of the anchorage decreases by approximately 14.3% with each additional scour depth of 0.33 H ( H denotes the embedded depth of the anchorage), and different loading modes exert slight effects on the ultimate bearing capacity. Numerical simulation results indicate that at the prototype site, the ultimate bearing capacity declines at a rate of about 10.3% when the scour depth increases stepwise by 0.2 H . Although slight numerical differences exist between simulation and test results, their overall variation trends are consistent. As scour intensifies, the failure mode of the anchorage gradually transitions from overturning-dominated to global sliding. Among the constitutive parameters of surrounding soil, the internal friction angle exerts the most significant influence on the ultimate bearing capacity, followed by cohesion, whereas the elastic modulus has a relatively minor effect.
2026,54(5):155-163
DOI: 10.3876/j.issn.1000-1980.2026.05.018
Abstract:
In view of the problem of the seepage behavior of fluids in low-permeability media, such as the lining and grouting zone of subsea tunnels, may deviate from Darcy seepage, the Hansbo nonlinear seepage model was employed to describe the seepage behavior within the lining and grouting zone. Analytical solutions for the nonlinear seepage field of a subsea tunnel under dynamic water levels were derived using the complex variable method and the method of images, respectively. Furthermore, an analytical model applicable to different support conditions, such as lining, grouting zone, or no support, was established. The accuracy of the analytical solutions was verified through comparisons with numerical simulation results, other theoretical analytical solutions, and laboratory model test results, and the effects of factors such as the nonlinear parameter, dynamic water levels, and the ratio of grouting zone thickness to lining thickness on the seepage field were analyzed. The results show that as the nonlinear parameter increases, the tunnel water inflow decreases, and the grouting zone sustains greater pore water pressure, thereby reducing the pore water pressure sustained by the lining; under the action of periodic dynamic water levels, both the tunnel water inflow and pore water pressure vary periodically; the grouting zone can attenuate the influence of dynamic water levels on the lining, and as the ratio of grouting zone thickness to lining thickness increases, the tunnel water inflow further decreases and the pore water pressure sustained by the grouting zone increases, thereby reducing the pore water pressure sustained by the lining.
In view of the problem of the seepage behavior of fluids in low-permeability media, such as the lining and grouting zone of subsea tunnels, may deviate from Darcy seepage, the Hansbo nonlinear seepage model was employed to describe the seepage behavior within the lining and grouting zone. Analytical solutions for the nonlinear seepage field of a subsea tunnel under dynamic water levels were derived using the complex variable method and the method of images, respectively. Furthermore, an analytical model applicable to different support conditions, such as lining, grouting zone, or no support, was established. The accuracy of the analytical solutions was verified through comparisons with numerical simulation results, other theoretical analytical solutions, and laboratory model test results, and the effects of factors such as the nonlinear parameter, dynamic water levels, and the ratio of grouting zone thickness to lining thickness on the seepage field were analyzed. The results show that as the nonlinear parameter increases, the tunnel water inflow decreases, and the grouting zone sustains greater pore water pressure, thereby reducing the pore water pressure sustained by the lining; under the action of periodic dynamic water levels, both the tunnel water inflow and pore water pressure vary periodically; the grouting zone can attenuate the influence of dynamic water levels on the lining, and as the ratio of grouting zone thickness to lining thickness increases, the tunnel water inflow further decreases and the pore water pressure sustained by the grouting zone increases, thereby reducing the pore water pressure sustained by the lining.
2026,54(5):164-172
DOI: 10.3876/j.issn.1000-1980.2026.05.019
Abstract:
To achieve accurate prediction and effective control of PM2.5 concentration in dry bulk port areas, a multivariate hybrid prediction model based on support vector regression (SVR) integrating XGBoost feature selection and particle swarm optimization (PSO) intelligent optimization was proposed, namely XGBoost-PSO-SVR model. The differences in PM2.5 formation mechanisms and diffusion processes under meteorological conditions in ports were fully considered by the model. XGBoost was employed to quantify the key influencing factors, and the SVR optimized by PSO was utilized for accurate prediction. The case verification results of typical port areas in the Nanjing section of the Yangtze River show that the XGBoost-PSO-SVR model has strong robustness in the high-concentration range; compared with the univariate STL-ARIMA-SVR model, its MAE, MAPE, and RMSE decrease by 15.6%, 14.3%, and 24.9%, respectively; compared with the conventional multivariate SVR model, they decrease by 52.5%, 57.1%, and 37.7%, respectively. The XGBoost-PSO-SVR model has good prediction performance and can provide decision support for intelligent dust suppression in dry bulk port areas.
To achieve accurate prediction and effective control of PM2.5 concentration in dry bulk port areas, a multivariate hybrid prediction model based on support vector regression (SVR) integrating XGBoost feature selection and particle swarm optimization (PSO) intelligent optimization was proposed, namely XGBoost-PSO-SVR model. The differences in PM2.5 formation mechanisms and diffusion processes under meteorological conditions in ports were fully considered by the model. XGBoost was employed to quantify the key influencing factors, and the SVR optimized by PSO was utilized for accurate prediction. The case verification results of typical port areas in the Nanjing section of the Yangtze River show that the XGBoost-PSO-SVR model has strong robustness in the high-concentration range; compared with the univariate STL-ARIMA-SVR model, its MAE, MAPE, and RMSE decrease by 15.6%, 14.3%, and 24.9%, respectively; compared with the conventional multivariate SVR model, they decrease by 52.5%, 57.1%, and 37.7%, respectively. The XGBoost-PSO-SVR model has good prediction performance and can provide decision support for intelligent dust suppression in dry bulk port areas.
Shao Shihao, Tao Aifeng, Wang Youqi, Tian Peng, Xing Jinyang, Liu Jianhao, Xu Wei, Fan Jun, Chen Xinping, Han Yu
2026,54(5):173-180
DOI: 10.3876/j.issn.1000-1980.2026.05.020
Abstract:
To quantitatively evaluate the wave attenuation performance of oyster shell bags and further investigate the influence of reef roughness parameters on wave energy dissipation, a numerical model of oyster shell bags was established based on OpenFOAM. By changing parameters including relative reef height, relative reef crest width, incident wave steepness, and roughness, the wave attenuation characteristics of oyster reefs under regular waves were analyzed. The results show that the transmission coefficient decreases with the increase in each parameter, among which the relative reef height has the most significant influence. When the relative reef height is 1.0, the influence of roughness on wave attenuation is mainly reflected in the low-value range; when the roughness increases from 0 to 2.5, the transmission coefficient decreases by 23.6%, but as the roughness continues to increase, the transmission coefficient remains almost unchanged. Based on the analytical results, a prediction formula for the transmission coefficient was fitted using regression analysis, which provides a basis for evaluating the wave attenuation capacity of oyster shell bags.
To quantitatively evaluate the wave attenuation performance of oyster shell bags and further investigate the influence of reef roughness parameters on wave energy dissipation, a numerical model of oyster shell bags was established based on OpenFOAM. By changing parameters including relative reef height, relative reef crest width, incident wave steepness, and roughness, the wave attenuation characteristics of oyster reefs under regular waves were analyzed. The results show that the transmission coefficient decreases with the increase in each parameter, among which the relative reef height has the most significant influence. When the relative reef height is 1.0, the influence of roughness on wave attenuation is mainly reflected in the low-value range; when the roughness increases from 0 to 2.5, the transmission coefficient decreases by 23.6%, but as the roughness continues to increase, the transmission coefficient remains almost unchanged. Based on the analytical results, a prediction formula for the transmission coefficient was fitted using regression analysis, which provides a basis for evaluating the wave attenuation capacity of oyster shell bags.
2026,54(5):181-189
DOI: 10.3876/j.issn.1000-1980.2026.05.021
Abstract:
To optimize the composition of grout materials for offshore wind suction bucket foundations and verify the recyclability of suction buckets after construction with different grouts, 18 fluidity tests, 21 unconfined compressive strength tests and 6 suction bucket recovery tests were carried out to investigate the influence mechanisms of water-solid ratio (0.75, 1, 1.1, 2.5) and bentonite content (0%, 20%, 40%, 60%, 80%, 100%) on the fluidity and compressive strength of grout materials, as well as the recyclability of suction buckets in clay with different grouts. The results show that at a fixed water-solid ratio, the fluidity and compressive strength of grout materials decrease significantly with the increase of bentonite content, and the grout basically loses fluidity when the bentonite content is no less than 60%. At a fixed bentonite content, fluidity increases with rising water-solid ratio (210-290 mm for 20% bentonite content), while compressive strength decreases accordingly. Suction buckets with grouts containing 60% and 100% bentonite can be successfully recovered by positive-pressure water injection inside the bucket. In contrast, grouts with 0% and 20% bentonite content fully solidify and completely block the water injection port, leading to recovery failure. It is recommended that the initial fluidity of grout be controlled within 250-300 mm and the fluidity after 30 min be no less than 200 mm. A bentonite content of 60% is preferred, and the water-solid ratio shall be increased until the required fluidity range is satisfied to balance the requirements of constructability, structural strength and recyclability.
To optimize the composition of grout materials for offshore wind suction bucket foundations and verify the recyclability of suction buckets after construction with different grouts, 18 fluidity tests, 21 unconfined compressive strength tests and 6 suction bucket recovery tests were carried out to investigate the influence mechanisms of water-solid ratio (0.75, 1, 1.1, 2.5) and bentonite content (0%, 20%, 40%, 60%, 80%, 100%) on the fluidity and compressive strength of grout materials, as well as the recyclability of suction buckets in clay with different grouts. The results show that at a fixed water-solid ratio, the fluidity and compressive strength of grout materials decrease significantly with the increase of bentonite content, and the grout basically loses fluidity when the bentonite content is no less than 60%. At a fixed bentonite content, fluidity increases with rising water-solid ratio (210-290 mm for 20% bentonite content), while compressive strength decreases accordingly. Suction buckets with grouts containing 60% and 100% bentonite can be successfully recovered by positive-pressure water injection inside the bucket. In contrast, grouts with 0% and 20% bentonite content fully solidify and completely block the water injection port, leading to recovery failure. It is recommended that the initial fluidity of grout be controlled within 250-300 mm and the fluidity after 30 min be no less than 200 mm. A bentonite content of 60% is preferred, and the water-solid ratio shall be increased until the required fluidity range is satisfied to balance the requirements of constructability, structural strength and recyclability.
2026,54(5):190-198
DOI: 10.3876/j.issn.1000-1980.2026.05.022
Abstract:
To improve the on-site stability of navigational buoys for submarine cable routes under extreme environments and optimize their motion response and mooring tension, this study takes a 2.4 m-diameter all-steel deep-water buoy as the research object, and conducts a comparative analysis of the motion responses of the buoy and mooring tension under single-point mooring (SPM) and three-point mooring (TPM) systems. Under the premise of ensuring consistent total weight and initial pretension of the mooring chains, SPM and TPM systems were designed. A time-domain coupled dynamic response calculation model for the buoy and mooring systems was established, and the buoy’s motion responses and mooring tensions were compared and analyzed under the action of different regular wave heights/periods and the extreme typhoon condition of “Rammasun”. The results show that: the motion responses amplitudes of the buoy and mooring tension are mainly affected by wave height, while influence of wave period is weak; compared with SPM system, TPM system can effectively reduce the amplitude of the buoy’s motion response and the mooring tension. TPM system layout method proposed in this study can provide a reference for the design improvement of the currently commonly used SPM buoys.
To improve the on-site stability of navigational buoys for submarine cable routes under extreme environments and optimize their motion response and mooring tension, this study takes a 2.4 m-diameter all-steel deep-water buoy as the research object, and conducts a comparative analysis of the motion responses of the buoy and mooring tension under single-point mooring (SPM) and three-point mooring (TPM) systems. Under the premise of ensuring consistent total weight and initial pretension of the mooring chains, SPM and TPM systems were designed. A time-domain coupled dynamic response calculation model for the buoy and mooring systems was established, and the buoy’s motion responses and mooring tensions were compared and analyzed under the action of different regular wave heights/periods and the extreme typhoon condition of “Rammasun”. The results show that: the motion responses amplitudes of the buoy and mooring tension are mainly affected by wave height, while influence of wave period is weak; compared with SPM system, TPM system can effectively reduce the amplitude of the buoy’s motion response and the mooring tension. TPM system layout method proposed in this study can provide a reference for the design improvement of the currently commonly used SPM buoys.
2026,54(5):199-208
DOI: 10.3876/j.issn.1000-1980.2026.05.023
Abstract:
In view of the frequent uncertain voltage fluctuations and even limit violations at buses caused by the high penetration rate of renewable energy generation and emerging loads, an analytical calculation method for voltage fluctuation intervals under uncertain power disturbances was proposed. This method employed an interval model and a non-parametric approach to characterize uncertainties and could rapidly obtain the voltage fluctuation intervals of each bus through analytical calculations using only the disturbance intervals of bus injected power. On this basis, an optimization model aimed at minimizing the adjustment cost was established to determine the power adjustment measures for mitigating voltage fluctuations, and a voltage fluctuation mitigation strategy utilizing adjustable loads during voltage limit violations was subsequently proposed to restore voltages to the allowable range. Simulation results on the IEEE 39-bus system show that the errors of the upper and lower bounds of the voltage fluctuation intervals obtained by the proposed analytical calculation method are around 1%. Furthermore, the proposed over-limit mitigation strategy is highly effective.
In view of the frequent uncertain voltage fluctuations and even limit violations at buses caused by the high penetration rate of renewable energy generation and emerging loads, an analytical calculation method for voltage fluctuation intervals under uncertain power disturbances was proposed. This method employed an interval model and a non-parametric approach to characterize uncertainties and could rapidly obtain the voltage fluctuation intervals of each bus through analytical calculations using only the disturbance intervals of bus injected power. On this basis, an optimization model aimed at minimizing the adjustment cost was established to determine the power adjustment measures for mitigating voltage fluctuations, and a voltage fluctuation mitigation strategy utilizing adjustable loads during voltage limit violations was subsequently proposed to restore voltages to the allowable range. Simulation results on the IEEE 39-bus system show that the errors of the upper and lower bounds of the voltage fluctuation intervals obtained by the proposed analytical calculation method are around 1%. Furthermore, the proposed over-limit mitigation strategy is highly effective.
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2018,46(2):128-133, DOI: 10.3876/j.issn.1000-1980.2018.02.005
Abstract:
To improve the operational safety of earth rockfill dam, a longitudinal reinforcement is proposed. This rigid structure has triple functions as the seepage controlling, stress resistance and deformation resistance. Based on the classical mechanics, its anti-seepage effect, anti-deformation ability and the capacity to withstand external force is quantitatively analyzed. In addition, the quantitative relationships between the reinforcement thickness and the downstream water level, as well as the material properties of the rockfill dam are derived. For the theoretical derivation, the reinforced body is regarded as a fixed-end beam, loaded by water pressures from upstream and downstream, the active earth pressure from rockfill and the vertical drag force due to the differential settlement between core walls and rockfill. The top displacement together with the rotation angle and the bottom stress of the fixed end are derived from the deformation differential equation and validated through designing reviews. Subsequently, the construction method of buried steel pipe, which is adopted to perform the base grouting and also to meet the strength requirements, is put forward. The proposed method plays an important guiding role in rehabilitating and reinforcing the dangerous earth rockfill dams, as well as the design and construction of new dams.
To improve the operational safety of earth rockfill dam, a longitudinal reinforcement is proposed. This rigid structure has triple functions as the seepage controlling, stress resistance and deformation resistance. Based on the classical mechanics, its anti-seepage effect, anti-deformation ability and the capacity to withstand external force is quantitatively analyzed. In addition, the quantitative relationships between the reinforcement thickness and the downstream water level, as well as the material properties of the rockfill dam are derived. For the theoretical derivation, the reinforced body is regarded as a fixed-end beam, loaded by water pressures from upstream and downstream, the active earth pressure from rockfill and the vertical drag force due to the differential settlement between core walls and rockfill. The top displacement together with the rotation angle and the bottom stress of the fixed end are derived from the deformation differential equation and validated through designing reviews. Subsequently, the construction method of buried steel pipe, which is adopted to perform the base grouting and also to meet the strength requirements, is put forward. The proposed method plays an important guiding role in rehabilitating and reinforcing the dangerous earth rockfill dams, as well as the design and construction of new dams.
2019,47(1):1-6, DOI: 10.3876/j.issn.1000-1980.2019.01.001
Abstract:
To improve the accuracy of flood forecasting, 13 flood events between 2000 and 2017 were selected from the sections of Lutaizi and Lubeng, and the Xin’anjiang three-source model(XAJ model)was used to simulate the flood events. The Lutaizi basin can be divided into 9 natural sub-basins and the Lubeng basin can be divided into 4 natural sub-basins. Then, the XAJ model was calibrated for these basins. The node generalizability was carried out in the mainstream section of the Huaihe River with flood diversion and flood retarding areas. Combined with the diversion ratio method and the Muskingen method, the simulation method of flood diversion was established, and fairly good forecasting results were obtained. The research results show that: for the relative error of flood volume, the qualified rates of Lutaizi and Lubeng region are both up to 100%, and the Lutaizi reached a qualified rate of 100% in the flood peak, while the Lubeng region reached 92. 3%. In two floods in 2003 and 2007, the relative error and the certainty coefficient of flood peak have been significantly improved.
To improve the accuracy of flood forecasting, 13 flood events between 2000 and 2017 were selected from the sections of Lutaizi and Lubeng, and the Xin’anjiang three-source model(XAJ model)was used to simulate the flood events. The Lutaizi basin can be divided into 9 natural sub-basins and the Lubeng basin can be divided into 4 natural sub-basins. Then, the XAJ model was calibrated for these basins. The node generalizability was carried out in the mainstream section of the Huaihe River with flood diversion and flood retarding areas. Combined with the diversion ratio method and the Muskingen method, the simulation method of flood diversion was established, and fairly good forecasting results were obtained. The research results show that: for the relative error of flood volume, the qualified rates of Lutaizi and Lubeng region are both up to 100%, and the Lutaizi reached a qualified rate of 100% in the flood peak, while the Lubeng region reached 92. 3%. In two floods in 2003 and 2007, the relative error and the certainty coefficient of flood peak have been significantly improved.
2020,48(1):1-7, DOI: 10.3876/j.issn.1000-1980.2020.01.001
Abstract:
Based on the development of hydrology science and the basic framework of physical and virtual water coupled flow theory, this study indicated that the process hydrology is an interdiscipline that can reveal the coupled flow law and associated effects of physical and virtual water in complicated system. In addition, this study makes a detailed analysis of the scientific connotation, main characteristics, framework, discipline basis, method system and core tasks of process hydrology. Given the theoretical value and practical significance of process hydrology, it can be concluded that the development of process hydrology can provide measures and new views to cope with new challenges in hydrology that the sustainable developments of nature, economy and society faces.
Based on the development of hydrology science and the basic framework of physical and virtual water coupled flow theory, this study indicated that the process hydrology is an interdiscipline that can reveal the coupled flow law and associated effects of physical and virtual water in complicated system. In addition, this study makes a detailed analysis of the scientific connotation, main characteristics, framework, discipline basis, method system and core tasks of process hydrology. Given the theoretical value and practical significance of process hydrology, it can be concluded that the development of process hydrology can provide measures and new views to cope with new challenges in hydrology that the sustainable developments of nature, economy and society faces.
2021,49(1):1-6, DOI: 10. 3876/ j. issn.1000-1980.2021.01.001
Abstract:
This study introduces the basic situation of China‘s small and medium-sized rivers and flood disasters, and then key difficulties as well as urgent scientific and technological problems in the flood prevention of small and medium-sized rivers were analyzed. Thereafter, the study puts forward the strategy and measures for the flood forecasting and early warning of small and medium- sized rivers. Besides, prospects for the future forecasting, risk early warning, and refined risk management concepts and practices are also proposed. It will realize the change from the hydrological element forecasting to the flood impact forecasting, from the flood threshold-based warning to the flood risk warning, from the " prediction-response" emergency disposal to the grid refinement risk management, from the monitoring data provision to the information product service, in which the development level of the hydrological modernization is continuously improved.
This study introduces the basic situation of China‘s small and medium-sized rivers and flood disasters, and then key difficulties as well as urgent scientific and technological problems in the flood prevention of small and medium-sized rivers were analyzed. Thereafter, the study puts forward the strategy and measures for the flood forecasting and early warning of small and medium- sized rivers. Besides, prospects for the future forecasting, risk early warning, and refined risk management concepts and practices are also proposed. It will realize the change from the hydrological element forecasting to the flood impact forecasting, from the flood threshold-based warning to the flood risk warning, from the " prediction-response" emergency disposal to the grid refinement risk management, from the monitoring data provision to the information product service, in which the development level of the hydrological modernization is continuously improved.
2020,48(1):22-28, DOI: 10.3876/j.issn.1000-1980.2020.01.004
Abstract:
This study reviewed the environmental behavior of microplastics(including the adsorption of organic pollutants and the release of organic additives after entering water), and the interaction between microplastics and organic pollutants after entering into water body, including its mechanism, influencing factors and biological toxicity. It also analyzed the deficiencies of current researches, and believed that, in order to provide theoretical basis for further study on the behavior and function of microplastics, it is necessary to expand the research on the interaction between microplastics and organic pollutants, such as strengthening the research in the freshwater environment, establishing systematic research system, and paying attention to the effect of biofilm
This study reviewed the environmental behavior of microplastics(including the adsorption of organic pollutants and the release of organic additives after entering water), and the interaction between microplastics and organic pollutants after entering into water body, including its mechanism, influencing factors and biological toxicity. It also analyzed the deficiencies of current researches, and believed that, in order to provide theoretical basis for further study on the behavior and function of microplastics, it is necessary to expand the research on the interaction between microplastics and organic pollutants, such as strengthening the research in the freshwater environment, establishing systematic research system, and paying attention to the effect of biofilm
2019,47(1):7-12, DOI: 10.3876/j.issn.1000-1980.2019.01.002
Abstract:
In order to make full use of the continues pumping test data to estimate the hydraulic conductivity(K), the transmissivity(T)and the storage coefficient(μ*)of different head depression cones in a confined aquifer, a dimensionless analytical solution of drawdown transients with variable pumping rates was derived based on the Theis formula and the principle of superposition. Furthermore, a new type curve method was proposed. The in-situ pumping test was conducted to obtain the drawdown record perturbed by stepwise rates. Then, the drawdown curve was used to match the corresponding type curve. After that, this method selects one match point and records its coordinate values on both the type curve and the real drawdown curve. By substituting these recorded values into related formulas, the hydraulic parameters of the confined aquifer can be determined. This method was applied to a field pumping test conducted at a southern highway in Wuxi, Jiangsu Province, China. The type curve matching process is implemented in stages. Field test results reveal that the hydraulic conductivity of the confined aquifer with the 2-3 silt layer are 5. 12×10-4 cm/s, 2. 54×10-3 cm/s and 2. 83×10-3 cm/s respectively, which are corresponding to three-stage stepwise pumping rates.
In order to make full use of the continues pumping test data to estimate the hydraulic conductivity(K), the transmissivity(T)and the storage coefficient(μ*)of different head depression cones in a confined aquifer, a dimensionless analytical solution of drawdown transients with variable pumping rates was derived based on the Theis formula and the principle of superposition. Furthermore, a new type curve method was proposed. The in-situ pumping test was conducted to obtain the drawdown record perturbed by stepwise rates. Then, the drawdown curve was used to match the corresponding type curve. After that, this method selects one match point and records its coordinate values on both the type curve and the real drawdown curve. By substituting these recorded values into related formulas, the hydraulic parameters of the confined aquifer can be determined. This method was applied to a field pumping test conducted at a southern highway in Wuxi, Jiangsu Province, China. The type curve matching process is implemented in stages. Field test results reveal that the hydraulic conductivity of the confined aquifer with the 2-3 silt layer are 5. 12×10-4 cm/s, 2. 54×10-3 cm/s and 2. 83×10-3 cm/s respectively, which are corresponding to three-stage stepwise pumping rates.
2020,48(2):95-101, DOI: 10.3876/j.issn.1000-1980.2020.02.001
Abstract:
Although the Piecewise Muskingum method for river flood calculation has been widely used in China, the major limitation that hinders the further application of the Piecewise Muskingum method within distributed models still needs to be addressed. This method with empirical parameters cannot consider the impact of changing river cross-section characteristics and hydraulic roughness on the flood computation. In this study, the Muskingum-Cunge-Todini variable parameter method and the non-linear reservoir method, which could consider the channel cross-section geometry and hydraulic roughness, were used in the river flood calculation in the middle part of Huaihe river, from Wujiadu to Xiaoliuxiang, and the middle part of Hutuo River, from Huangbizhuang to Beizhongshan. In addition, the river flood calculation with the Piecewise Muskingum method also has been conducted as a comparison. Initial tests indicate that the Muskingum-Cunge-Todini variable parameter method and the non-linear reservoir method have high simulation accuracy in the studied cases. The correct rate of flood peak is above 86%, and the coefficient of certainty is greater than 0. 8. This study can provide references for the flood calculation considering the change of the channel cross section and hydraulic roughness characteristics.
Although the Piecewise Muskingum method for river flood calculation has been widely used in China, the major limitation that hinders the further application of the Piecewise Muskingum method within distributed models still needs to be addressed. This method with empirical parameters cannot consider the impact of changing river cross-section characteristics and hydraulic roughness on the flood computation. In this study, the Muskingum-Cunge-Todini variable parameter method and the non-linear reservoir method, which could consider the channel cross-section geometry and hydraulic roughness, were used in the river flood calculation in the middle part of Huaihe river, from Wujiadu to Xiaoliuxiang, and the middle part of Hutuo River, from Huangbizhuang to Beizhongshan. In addition, the river flood calculation with the Piecewise Muskingum method also has been conducted as a comparison. Initial tests indicate that the Muskingum-Cunge-Todini variable parameter method and the non-linear reservoir method have high simulation accuracy in the studied cases. The correct rate of flood peak is above 86%, and the coefficient of certainty is greater than 0. 8. This study can provide references for the flood calculation considering the change of the channel cross section and hydraulic roughness characteristics.
2015,43(5):384-394, DOI: 10.3876/j.issn.1000-1980.2015.05.002
Abstract:
Water resources constraints constitute a significant bottleneck in China. The origins of water are worth further research, as they relate to the Earth’s formation, the origins of the water globe, and the issue of deep water. First, we attempt to divide the hydrosphere into several belts and focus on the complex interaction between spherical layers. Then, water resources development issues are discussed, the concept of the comprehensive effect and related evaluation of the evolution of an entire basin is developed based on the spherical layer movement, and the evolution of the middle reaches of the Yellow River, the middle and upper reaches of the Yangtze River, and the inland river basin is analyzed based on this concept. Water resources development should consider three properties: limits, relativity, and ecology, as well as the instructive observation that water can carry a boat and also overturn a boat. The comprehensive development and utilization of water from six different sources, including rainwater, river water, lake water, groundwater, reservoir water, and sea water, are examined. We also discuss prevention and mitigation of six types of disasters related to the six water sources: flooding, waterlogging, drought, storm surges, geological disasters, and water pollution. It is pointed out that segmented control of water quality in the reservoir area, comprehensive development of surface water and groundwater, and construction of underground reservoirs are important. Finally, some suggestions for water resources development and disaster prevention are proposed: cooperation between multiple departments and multiple disciplines, implementation of water-saving measures, construction of an enhanced water resources network, determination of demand according to provision, and improvement of an investigation system for evaluation and development.
Water resources constraints constitute a significant bottleneck in China. The origins of water are worth further research, as they relate to the Earth’s formation, the origins of the water globe, and the issue of deep water. First, we attempt to divide the hydrosphere into several belts and focus on the complex interaction between spherical layers. Then, water resources development issues are discussed, the concept of the comprehensive effect and related evaluation of the evolution of an entire basin is developed based on the spherical layer movement, and the evolution of the middle reaches of the Yellow River, the middle and upper reaches of the Yangtze River, and the inland river basin is analyzed based on this concept. Water resources development should consider three properties: limits, relativity, and ecology, as well as the instructive observation that water can carry a boat and also overturn a boat. The comprehensive development and utilization of water from six different sources, including rainwater, river water, lake water, groundwater, reservoir water, and sea water, are examined. We also discuss prevention and mitigation of six types of disasters related to the six water sources: flooding, waterlogging, drought, storm surges, geological disasters, and water pollution. It is pointed out that segmented control of water quality in the reservoir area, comprehensive development of surface water and groundwater, and construction of underground reservoirs are important. Finally, some suggestions for water resources development and disaster prevention are proposed: cooperation between multiple departments and multiple disciplines, implementation of water-saving measures, construction of an enhanced water resources network, determination of demand according to provision, and improvement of an investigation system for evaluation and development.
2017,45(3):277-282, DOI: 10.3876/j.issn.1000-1980.2017.03.014
Abstract:
It is necessary to monitor the state of ZnO arresters to guarantee their safe operation. In order to select a best way to monitor the state of arresters, the advantages, disadvantages, and application of each monitoring method were analyzed. The results show that the harmonic analysis method is the most effective method. The properties of the harmonic analysis method in practical application could be improved by modifying the resistive leakage current and selecting an appropriate window function when conducting fast discrete Fourier transform on the collected signals. Through review of monitoring technologies in China and abroad, it can be found that in the future, the overall development trend of online monitoring methods of ZnO arresters is to develop fully automatic and multi-functional integrated online insulation monitoring systems.
It is necessary to monitor the state of ZnO arresters to guarantee their safe operation. In order to select a best way to monitor the state of arresters, the advantages, disadvantages, and application of each monitoring method were analyzed. The results show that the harmonic analysis method is the most effective method. The properties of the harmonic analysis method in practical application could be improved by modifying the resistive leakage current and selecting an appropriate window function when conducting fast discrete Fourier transform on the collected signals. Through review of monitoring technologies in China and abroad, it can be found that in the future, the overall development trend of online monitoring methods of ZnO arresters is to develop fully automatic and multi-functional integrated online insulation monitoring systems.
2020,48(3):189-194, DOI: 10.3876/j.issn.1000-1980.2020.03.001
Abstract:
On the basis of the original Xin’anjiang model, this study solved the matching problem between sub-catchment and grid channel, and enabled the model to calculate channel routing according to actual river conditions. A hybrid rainfall-runoff model(named XAJ-DCH)was further proposed by coupling the XAJ model with diffusion wave method and Muskingum-Cunge-Todini(MCT)method by accounting for the lateral inflow. The flood prediction capabilities of the traditional XAJ model and the XAJ-DCH model were compared at hourly scale for the Chengcun catchment. The performance of both models is comparable and satisfactory, and thus, the rationality of the new model is verified. By improving the channel routing method in the Xin’anjiang model, the spatiotemporal variability can be further considered. Furthermore, compared with the Xin’anjiang model, the XAJ-DCH model can not only be used to simulate the discharge at the outlet station, but also to predict the water level and discharge of the interior station in the catchment. In addition, the diffusion wave method was introduced into the XAJ-DCH model, which can improve the prediction accuracy in hydraulically mild slope area by accounting for the backwater effects.
On the basis of the original Xin’anjiang model, this study solved the matching problem between sub-catchment and grid channel, and enabled the model to calculate channel routing according to actual river conditions. A hybrid rainfall-runoff model(named XAJ-DCH)was further proposed by coupling the XAJ model with diffusion wave method and Muskingum-Cunge-Todini(MCT)method by accounting for the lateral inflow. The flood prediction capabilities of the traditional XAJ model and the XAJ-DCH model were compared at hourly scale for the Chengcun catchment. The performance of both models is comparable and satisfactory, and thus, the rationality of the new model is verified. By improving the channel routing method in the Xin’anjiang model, the spatiotemporal variability can be further considered. Furthermore, compared with the Xin’anjiang model, the XAJ-DCH model can not only be used to simulate the discharge at the outlet station, but also to predict the water level and discharge of the interior station in the catchment. In addition, the diffusion wave method was introduced into the XAJ-DCH model, which can improve the prediction accuracy in hydraulically mild slope area by accounting for the backwater effects.
2020,48(4):377-384, DOI: 10.3876/j.issn.1000-1980.2020.04.013
Abstract:
Firstly, the necessity of power electronization is explained from the development history of the power electronics and the challenges in power generation, transmission, distribution, and consumption. Secondly, the driving factors of power electronization, such as politics, economy, and technology, are elaborated in three aspects, including energy security and political construction, the resource and environmental benefits, and the transformation of power generation, transmission, distribution and consumption. Finally, the development trends and main restrictive factors of power electronization in power system are analyzed, and related study directions are summarized to provide some references and suggestions for future study.
Firstly, the necessity of power electronization is explained from the development history of the power electronics and the challenges in power generation, transmission, distribution, and consumption. Secondly, the driving factors of power electronization, such as politics, economy, and technology, are elaborated in three aspects, including energy security and political construction, the resource and environmental benefits, and the transformation of power generation, transmission, distribution and consumption. Finally, the development trends and main restrictive factors of power electronization in power system are analyzed, and related study directions are summarized to provide some references and suggestions for future study.
2022,50(2):1-10, DOI: 10.3876/j.issn.1000-1980.2022.02.001
Abstract:
In this study, a hydrological model parameter optimization scheme was constructed in SWAT based on streamflow assimilation using the ensemble Kalman filter(EnKF)approach, in which the model simulation and streamflow observation errors were reasonably quantified and the model parameter evolution and over-fitting issues were effectively treated. Based on this scheme, the capacity of streamflow assimilation on SWAT model parameter optimization was evaluated in the upper Huai River above Huaibin hydrological station. The results showed that the updated parameter ensemble gradually converged and stabilized during the data assimilation process. The runoff process based on the stabilized parameter ensemble was close to the measured runoff. The deterministic coefficient at the outlet of the basin reached 0. 88. The results indicated that the EnKF based streamflow assimilation had the ability to optimize the parameters in SWAT. It was feasible to calibrate model parameters using data assimilation method.
In this study, a hydrological model parameter optimization scheme was constructed in SWAT based on streamflow assimilation using the ensemble Kalman filter(EnKF)approach, in which the model simulation and streamflow observation errors were reasonably quantified and the model parameter evolution and over-fitting issues were effectively treated. Based on this scheme, the capacity of streamflow assimilation on SWAT model parameter optimization was evaluated in the upper Huai River above Huaibin hydrological station. The results showed that the updated parameter ensemble gradually converged and stabilized during the data assimilation process. The runoff process based on the stabilized parameter ensemble was close to the measured runoff. The deterministic coefficient at the outlet of the basin reached 0. 88. The results indicated that the EnKF based streamflow assimilation had the ability to optimize the parameters in SWAT. It was feasible to calibrate model parameters using data assimilation method.
2020,48(2):102-108, DOI: 10.3876/j.issn.1000-1980.2020.02.002
Abstract:
In order to obtain the characteristics of wind field and flow field as well as the influence of different types of wind fields on the flow field of Taihu Lake, 6 acoustic doppler current profilers(ADCP)and 4 meteorological stations were set up in different areas of Taihu Lake, and the synchronous data of flow field and wind field were obtained. The results show the floolwing: (a)The spatial distribution of wind field in Taihu Lake was not uniform, the wind speed varied greatly among 4 stations, and the difference of wind direction was expanded along with the decrease of wind speed. (b)The flow field in Taihu Lake had obvious characteristics of wind-generated flow. When the average wind speed was greater than 6. 7 m/s, there was a counterclockwise circulation that appeared in the western lake area, and there was no obvious flow stratification during this period. When the average wind speed was less than 3. 8 m/s, the circulation in the west fade away. However, the flow stratification was obviously developed, the current direction of each layer was relatively stable but different, and the compensation flow developed. (c)According to the observed data, the percentage of current speed less than 10 cm/s was more than 90%, and the current speed can reach 20 cm/s under strong wind conditions.
In order to obtain the characteristics of wind field and flow field as well as the influence of different types of wind fields on the flow field of Taihu Lake, 6 acoustic doppler current profilers(ADCP)and 4 meteorological stations were set up in different areas of Taihu Lake, and the synchronous data of flow field and wind field were obtained. The results show the floolwing: (a)The spatial distribution of wind field in Taihu Lake was not uniform, the wind speed varied greatly among 4 stations, and the difference of wind direction was expanded along with the decrease of wind speed. (b)The flow field in Taihu Lake had obvious characteristics of wind-generated flow. When the average wind speed was greater than 6. 7 m/s, there was a counterclockwise circulation that appeared in the western lake area, and there was no obvious flow stratification during this period. When the average wind speed was less than 3. 8 m/s, the circulation in the west fade away. However, the flow stratification was obviously developed, the current direction of each layer was relatively stable but different, and the compensation flow developed. (c)According to the observed data, the percentage of current speed less than 10 cm/s was more than 90%, and the current speed can reach 20 cm/s under strong wind conditions.
2015,43(4):288-293, DOI: 10.3876/j.issn.1000-1980.2015.04.002
Abstract:
Considering the hydrological calculation and prediction of ungauged basins, a distributed hydrological model, the THREW model, was adopted to study the upper basin of the Brahmaputra River from the Nuxia Hydrological Station. Surface meteorological observation, remote sensing of vegetation cover, snow cover area, and section hydrological monitoring data were used to calibrate the model, and the latest CMIP5 data were used to estimate the runoff evolution. The results showed that, in the upper basin of the Brahmaputra River from the Nuxia Hydrological Station, the Nash-Sutcliffe efficiency coefficient of monthly runoff simulation of the calibration period from 1991 to 1995 was 0. 75, the coefficient of monthly runoff simulation of the validation period from 1996 to 2000 was 0. 76, and the runoff markedly increased when the CO2 discharge in the AR5 of IPCC was maximal.
Considering the hydrological calculation and prediction of ungauged basins, a distributed hydrological model, the THREW model, was adopted to study the upper basin of the Brahmaputra River from the Nuxia Hydrological Station. Surface meteorological observation, remote sensing of vegetation cover, snow cover area, and section hydrological monitoring data were used to calibrate the model, and the latest CMIP5 data were used to estimate the runoff evolution. The results showed that, in the upper basin of the Brahmaputra River from the Nuxia Hydrological Station, the Nash-Sutcliffe efficiency coefficient of monthly runoff simulation of the calibration period from 1991 to 1995 was 0. 75, the coefficient of monthly runoff simulation of the validation period from 1996 to 2000 was 0. 76, and the runoff markedly increased when the CO2 discharge in the AR5 of IPCC was maximal.
Journal information
- Supervisory Authority
Ministry of Education，P.R.China
- Sponsored by
Hohai University
- Editor-in-Chief
ZHENG Jinhai
- Address：
No.1 Xikang Road, Nanjing 210098, P.R. China
- Postcode：
210098
- Phone：
025-83786642
- E-mail：
xb1957@vip.163.com;xb@hhu.edu.cn
- CN：
32-1117/TV
- ISSN：
1000-1980
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