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2025,53(6):1-11
DOI: 10.3876/j.issn.1000-1980.2025.06.001
Abstract:
To conduct a comprehensive evaluation of resource utilization efficiency, an efficiency assessment framework that combined multi-regional input-output analysis and data envelopment analysis was proposed. This framework was employed to calculate the water, energy, and food footprints on the consumption side of cities in Guangdong Province. On this basis, input-output efficiency under the influence of inter-regional trade was assessed from the perspective of the water-energy-food system. The findings indicate that the cities’ water, energy, and food footprints on the consumption side are predominantly influenced by inflows from regions outside the province, followed by local consumption footprints. Other cities within the province receive a relatively negligible proportion of trade-implied resources. The spatial distribution characteristics of the water-energy-food system efficiency and the water, energy, and food footprints on the consumption side converge, primarily exhibiting a decreasing trend from the The Pearl River Delta region to the exterior. By taking into account the impact of inter-regional trade on water, energy, and food consumption, the efficiency of most cities has been improved, and the overall efficiency of the region has increased. Among the cities, Shenzhen and Zhongshan have demonstrated optimal input-output allocation, while the remaining cities have exhibited varying degrees of input redundancy, with Guangzhou exhibiting the greatest potential for resource savings.
To conduct a comprehensive evaluation of resource utilization efficiency, an efficiency assessment framework that combined multi-regional input-output analysis and data envelopment analysis was proposed. This framework was employed to calculate the water, energy, and food footprints on the consumption side of cities in Guangdong Province. On this basis, input-output efficiency under the influence of inter-regional trade was assessed from the perspective of the water-energy-food system. The findings indicate that the cities’ water, energy, and food footprints on the consumption side are predominantly influenced by inflows from regions outside the province, followed by local consumption footprints. Other cities within the province receive a relatively negligible proportion of trade-implied resources. The spatial distribution characteristics of the water-energy-food system efficiency and the water, energy, and food footprints on the consumption side converge, primarily exhibiting a decreasing trend from the The Pearl River Delta region to the exterior. By taking into account the impact of inter-regional trade on water, energy, and food consumption, the efficiency of most cities has been improved, and the overall efficiency of the region has increased. Among the cities, Shenzhen and Zhongshan have demonstrated optimal input-output allocation, while the remaining cities have exhibited varying degrees of input redundancy, with Guangzhou exhibiting the greatest potential for resource savings.
2025,53(6):12-20
DOI: 10.3876/j.issn.1000-1980.2025.06.002
Abstract:
By using simulation data of precipitation and temperature in the Huaihe River Basin from 1985 to 2014 from 22 global climate models (GCMs) of the coupled model intercomparison project in phase 6 (CMIP6), the simulation performance of GCMs was comprehensively assessed by means of a rank score method with seven indexes selected, and the sensitivity of the scores to each index was analyzed. The spatial simulation performance of the selected optimal GCMs was evaluated. The results reveal significant differences in the simulation performance of monthly average precipitation and temperature in the Huaihe River Basin among the models. Overall, the GCMs perform better in simulating temperatures, but there is a general overestimation of monthly average precipitation. The top five models with the best comprehensive rank score are EC-Earth3 (7.83), EC-Earth3-Veg (7.66), ACCESS-CM2 (7.62), TaiESM1 (7.27), and FGOALS-f3-L (7.20). The rank score results for precipitation are most sensitive to the standard deviation, the statistics of Mann-Kendall trend analysis ( z ), and the slope of Mann-Kendall ( β ), while those for temperature show high sensitivity to z and β . Different combinations of rank score indexes moderately influence the scores. The EC-Earth3 model, identified as the most optimal, accurately reproduces the spatial distribution of precipitation but performs slightly less effectively for the spatial distribution of temperature.
By using simulation data of precipitation and temperature in the Huaihe River Basin from 1985 to 2014 from 22 global climate models (GCMs) of the coupled model intercomparison project in phase 6 (CMIP6), the simulation performance of GCMs was comprehensively assessed by means of a rank score method with seven indexes selected, and the sensitivity of the scores to each index was analyzed. The spatial simulation performance of the selected optimal GCMs was evaluated. The results reveal significant differences in the simulation performance of monthly average precipitation and temperature in the Huaihe River Basin among the models. Overall, the GCMs perform better in simulating temperatures, but there is a general overestimation of monthly average precipitation. The top five models with the best comprehensive rank score are EC-Earth3 (7.83), EC-Earth3-Veg (7.66), ACCESS-CM2 (7.62), TaiESM1 (7.27), and FGOALS-f3-L (7.20). The rank score results for precipitation are most sensitive to the standard deviation, the statistics of Mann-Kendall trend analysis ( z ), and the slope of Mann-Kendall ( β ), while those for temperature show high sensitivity to z and β . Different combinations of rank score indexes moderately influence the scores. The EC-Earth3 model, identified as the most optimal, accurately reproduces the spatial distribution of precipitation but performs slightly less effectively for the spatial distribution of temperature.
2025,53(6):21-32
DOI: 10.3876/j.issn.1000-1980.2025.06.003
Abstract:
To study the spatiotemporal characteristics of groundwater storage changes in the hilly areas of Jiangxi Province, based on the gravity recovery and climate experiment (GRACE)/GRACE-FO satellite inversion data from 2003 to 2023, a spatiotemporal evolution analysis framework of groundwater integrating downscaling reconstruction and trend identification was constructed, revealing the pattern of changes in groundwater storage anomalies (GWSA). The high-resolution reconstruction of GWSA was carried out through a deep learning model. The long-term trend component was extracted using seasonal-trend decomposition using LOESS (STL). The groundwater change trend and its significance were identified by combining the Mann-Kendall test and the Theil-Sen slope estimation method. The results show that the reconstructed high-resolution GWSA data clearly reveal the spatiotemporal evolution characteristics of groundwater storage in the hilly areas of Jiangxi Province; after STL, the sequence shows a significant long-term trend and stable seasonal fluctuations. From 2003 to 2023, the groundwater level in the entire province has risen slowly, and the overall long-term trend shows an evolution pattern of “recovery in northeastern and central regions but continuous depletion in southern regions”. Notably, Ganzhou City in southern Jiangxi exhibits a significant decline in groundwater storage, making it a representative groundwater-deficit zone. Groundwater variations exhibit compound characteristics, including regional disparities, phased evolution, and intensified high-frequency anomalies, indicating that the system remains unstable and is in a critical state vulnerable to further depletion.
To study the spatiotemporal characteristics of groundwater storage changes in the hilly areas of Jiangxi Province, based on the gravity recovery and climate experiment (GRACE)/GRACE-FO satellite inversion data from 2003 to 2023, a spatiotemporal evolution analysis framework of groundwater integrating downscaling reconstruction and trend identification was constructed, revealing the pattern of changes in groundwater storage anomalies (GWSA). The high-resolution reconstruction of GWSA was carried out through a deep learning model. The long-term trend component was extracted using seasonal-trend decomposition using LOESS (STL). The groundwater change trend and its significance were identified by combining the Mann-Kendall test and the Theil-Sen slope estimation method. The results show that the reconstructed high-resolution GWSA data clearly reveal the spatiotemporal evolution characteristics of groundwater storage in the hilly areas of Jiangxi Province; after STL, the sequence shows a significant long-term trend and stable seasonal fluctuations. From 2003 to 2023, the groundwater level in the entire province has risen slowly, and the overall long-term trend shows an evolution pattern of “recovery in northeastern and central regions but continuous depletion in southern regions”. Notably, Ganzhou City in southern Jiangxi exhibits a significant decline in groundwater storage, making it a representative groundwater-deficit zone. Groundwater variations exhibit compound characteristics, including regional disparities, phased evolution, and intensified high-frequency anomalies, indicating that the system remains unstable and is in a critical state vulnerable to further depletion.
2025,53(6):33-40
DOI: 10.3876/j.issn.1000-1980.2025.06.004
Abstract:
Traditional reasoning formula methods and instantaneous unit hydrograph methods are difficult to reflect geomorphological features and land use changes in design flood calculation. To address this issue, a new design flood flow concentration calculation method, namely the runoff curve number (SCS) geomorphologic general unit hydrograph method, was proposed by considering the influence of geomorphological features and land use changes on the time of flow concentration. This method was coupled with the SCS model to establish a complete flow generation and concentration model, and the Shangbu River Watershed in Hangzhou City was taken as an example to verify the method. The verification results show that compared to traditional reasoning formula method and instantaneous unit hydrograph methods, the SCS geomorphologic general unit hydrograph method is more reasonable for calculating design floods in small watersheds within urbanized areas, as it better reflects the watershed’s geomorphological features and adapts to land use changes. Scenario analysis further reveals that the changes in underlying surface conditions caused by urbanization will lead to an increase in design flood volume and flood peak.
Traditional reasoning formula methods and instantaneous unit hydrograph methods are difficult to reflect geomorphological features and land use changes in design flood calculation. To address this issue, a new design flood flow concentration calculation method, namely the runoff curve number (SCS) geomorphologic general unit hydrograph method, was proposed by considering the influence of geomorphological features and land use changes on the time of flow concentration. This method was coupled with the SCS model to establish a complete flow generation and concentration model, and the Shangbu River Watershed in Hangzhou City was taken as an example to verify the method. The verification results show that compared to traditional reasoning formula method and instantaneous unit hydrograph methods, the SCS geomorphologic general unit hydrograph method is more reasonable for calculating design floods in small watersheds within urbanized areas, as it better reflects the watershed’s geomorphological features and adapts to land use changes. Scenario analysis further reveals that the changes in underlying surface conditions caused by urbanization will lead to an increase in design flood volume and flood peak.
2025,53(6):41-48, 56
DOI: 10.3876/j.issn.1000-1980.2025.06.005
Abstract:
To enhance the flood disaster response capability of Changchun City, a comprehensive evaluation indicator system for flood disaster response capability was constructed based on the pressure-state-response conceptual model. This system deconstructed the urban flood disaster system into three subsystems: pressure (P), state (S), and response (R), corresponding to disaster causes, loss status, and response measures, respectively. A total of 4, 6, and 4 core evaluation indicators were carefully selected for each subsystem. The entropy weight method was applied to calculate the temporal weights of each subsystem in Changchun City from 2002 to 2021, and the coupling coordination degree (CCD) model was used to analyze the dynamic coordination relationship between the S subsystem and the P and R subsystems. The results indicate that the P and R subsystems exhibit significant linear growth trends, reflecting increasing disaster-inducing pressures and enhanced response capabilities in the city, while the S subsystem does not show a clear trend. During 2010, 2013, and 2017, varying degrees of imbalance or declines in CCD have been observed between the S subsystem and the P and R subsystems, which closely coincide with relatively high precipitation levels during those years. The urban flood disaster response capability is significantly influenced by heavy rainfall, necessitating the synergistic integration of engineering and non-engineering technical strategies, as well as the optimization of urban planning, construction, and management strategies, so as to improve system coordination and disaster response effectiveness.
To enhance the flood disaster response capability of Changchun City, a comprehensive evaluation indicator system for flood disaster response capability was constructed based on the pressure-state-response conceptual model. This system deconstructed the urban flood disaster system into three subsystems: pressure (P), state (S), and response (R), corresponding to disaster causes, loss status, and response measures, respectively. A total of 4, 6, and 4 core evaluation indicators were carefully selected for each subsystem. The entropy weight method was applied to calculate the temporal weights of each subsystem in Changchun City from 2002 to 2021, and the coupling coordination degree (CCD) model was used to analyze the dynamic coordination relationship between the S subsystem and the P and R subsystems. The results indicate that the P and R subsystems exhibit significant linear growth trends, reflecting increasing disaster-inducing pressures and enhanced response capabilities in the city, while the S subsystem does not show a clear trend. During 2010, 2013, and 2017, varying degrees of imbalance or declines in CCD have been observed between the S subsystem and the P and R subsystems, which closely coincide with relatively high precipitation levels during those years. The urban flood disaster response capability is significantly influenced by heavy rainfall, necessitating the synergistic integration of engineering and non-engineering technical strategies, as well as the optimization of urban planning, construction, and management strategies, so as to improve system coordination and disaster response effectiveness.
2025,53(6):49-56
DOI: 10.3876/j.issn.1000-1980.2025.06.006
Abstract:
By taking the North Bund area in Shanghai’s Hongkou District, the core built-up area, as the study region, a 1D-2D coupled model integrating pipe network topology optimization and surface micro-topography refinement was developed to precisely simulate rainstorm waterlogging processes in urban high-density areas. The model’s reliability and applicability were dynamically validated using multiple recorded storm events from 2020 to 2024. Based on this model, two drainage system optimization schemes for the North Bund area were evaluated (Scheme 1: adding new main stormwater pipelines + upgrading the riverside pumping station; Scheme 2: retrofitting main pipelines + enhancing the efficiency of existing pumping stations). Results indicate that the constructed 1D-2D coupled model accurately simulates rainstorm waterlogging processes in urban high-density areas under various rainfall conditions. Under the design rainstorm scenario with a 10-year return period, Scheme 1 achieves a 52.5% reduction in overflow nodes and a 44.6% decrease in inundated area, demonstrating superior system resilience compared to Scheme 2 (47.3% overflow nodes reduction and 42.2% inundation area reduction)
By taking the North Bund area in Shanghai’s Hongkou District, the core built-up area, as the study region, a 1D-2D coupled model integrating pipe network topology optimization and surface micro-topography refinement was developed to precisely simulate rainstorm waterlogging processes in urban high-density areas. The model’s reliability and applicability were dynamically validated using multiple recorded storm events from 2020 to 2024. Based on this model, two drainage system optimization schemes for the North Bund area were evaluated (Scheme 1: adding new main stormwater pipelines + upgrading the riverside pumping station; Scheme 2: retrofitting main pipelines + enhancing the efficiency of existing pumping stations). Results indicate that the constructed 1D-2D coupled model accurately simulates rainstorm waterlogging processes in urban high-density areas under various rainfall conditions. Under the design rainstorm scenario with a 10-year return period, Scheme 1 achieves a 52.5% reduction in overflow nodes and a 44.6% decrease in inundated area, demonstrating superior system resilience compared to Scheme 2 (47.3% overflow nodes reduction and 42.2% inundation area reduction)
2025,53(6):57-64
DOI: 10.3876/j.issn.1000-1980.2025.06.007
Abstract:
To address the issues of the large amount of data required and the high difficulty in obtaining data during the modeling process of hydrodynamic water quality models, a method based on hydrological approaches for solving the basic equations of one-dimensional water quality models was proposed. This method substituted river topography and flow velocity data with Muskingum method parameters K and X for river confluence in hydrology. Moreover, coupled with the basic equations of the one-dimensional water quality model, a river pollution confluence model based on the Muskingum method was developed. Since taking a constant value for K is unreasonable for calculating pollutant propagation time in the developed model, the functions of K and X relative to flow rate Q were derived to solve this problem, and the nonlinear Muskingum model was coupled with the one-dimensional water quality model to build a river pollution confluence model based on the nonlinear Muskingum method. The verification results of the Dapuling-Changtaiguan section of the upper reaches of the Huai River show that the river pollution confluence model based on the nonlinear Muskingum method has ensured accurate prediction of peak time compared with the river pollution confluence model based on the Muskingum method. At the same time, the deterministic coefficient of the pollutant mass concentration prediction results has been increased by 0.04, the root mean square error has been reduced by 0.07 mg/L, and the average absolute error has been decreased by 0.022 mg/L.
To address the issues of the large amount of data required and the high difficulty in obtaining data during the modeling process of hydrodynamic water quality models, a method based on hydrological approaches for solving the basic equations of one-dimensional water quality models was proposed. This method substituted river topography and flow velocity data with Muskingum method parameters K and X for river confluence in hydrology. Moreover, coupled with the basic equations of the one-dimensional water quality model, a river pollution confluence model based on the Muskingum method was developed. Since taking a constant value for K is unreasonable for calculating pollutant propagation time in the developed model, the functions of K and X relative to flow rate Q were derived to solve this problem, and the nonlinear Muskingum model was coupled with the one-dimensional water quality model to build a river pollution confluence model based on the nonlinear Muskingum method. The verification results of the Dapuling-Changtaiguan section of the upper reaches of the Huai River show that the river pollution confluence model based on the nonlinear Muskingum method has ensured accurate prediction of peak time compared with the river pollution confluence model based on the Muskingum method. At the same time, the deterministic coefficient of the pollutant mass concentration prediction results has been increased by 0.04, the root mean square error has been reduced by 0.07 mg/L, and the average absolute error has been decreased by 0.022 mg/L.
2025,53(6):65-74
DOI: 10.3876/j.issn.1000-1980.2025.06.008
Abstract:
To investigate the spatiotemporal evolution patterns of precipitation in the Hubei section of the Three Gorges Reservoir Region under climate change, 187 precipitation samples collected from October 2022 to September 2023 were utilized to analyze the stable hydrogen and oxygen isotope characteristics of precipitation. The influence of meteorological factors such as temperature, precipitation amount, and relative humidity was examined. Additionally, the HYSPLIT model was used to trace water vapor transport trajectories and identify water vapor sources. The results indicate that there are obvious seasonal variations of stable hydrogen and oxygen isotopes in precipitation in the Hubei section of the Three Gorges Reservoir Region, with relative depletion in summer and autumn and relative enrichment in winter and spring. The relationship between δD and δ 18O in the study area is δD=8.21 δ 18O+11.23( R 2=0.94, p ＜0.01). It reflects the regional wet and rainy climatic characteristics.Precipitation amount and relative humidity are the main factors affecting the stable hydrogen and oxygen isotopes in precipitation. Temperature is the dominant factor influencing d-excess. Seasonal variations are observed in the sources of precipitation for the study area. In summer, precipitation mainly comes from the water vapor of the Pacific Ocean, South China Sea, and Indian Ocean carried by the southeast monsoon and the southwest monsoon. In winter, precipitation primarily derives from the west and northwest directions of the Eurasian continent. Spring and autumn serve as transitional periods, witnessing shifts in the predominant source of precipitation between the ocean and land.
To investigate the spatiotemporal evolution patterns of precipitation in the Hubei section of the Three Gorges Reservoir Region under climate change, 187 precipitation samples collected from October 2022 to September 2023 were utilized to analyze the stable hydrogen and oxygen isotope characteristics of precipitation. The influence of meteorological factors such as temperature, precipitation amount, and relative humidity was examined. Additionally, the HYSPLIT model was used to trace water vapor transport trajectories and identify water vapor sources. The results indicate that there are obvious seasonal variations of stable hydrogen and oxygen isotopes in precipitation in the Hubei section of the Three Gorges Reservoir Region, with relative depletion in summer and autumn and relative enrichment in winter and spring. The relationship between δD and δ 18O in the study area is δD=8.21 δ 18O+11.23( R 2=0.94, p ＜0.01). It reflects the regional wet and rainy climatic characteristics.Precipitation amount and relative humidity are the main factors affecting the stable hydrogen and oxygen isotopes in precipitation. Temperature is the dominant factor influencing d-excess. Seasonal variations are observed in the sources of precipitation for the study area. In summer, precipitation mainly comes from the water vapor of the Pacific Ocean, South China Sea, and Indian Ocean carried by the southeast monsoon and the southwest monsoon. In winter, precipitation primarily derives from the west and northwest directions of the Eurasian continent. Spring and autumn serve as transitional periods, witnessing shifts in the predominant source of precipitation between the ocean and land.
Soil moisture inversion in Anhui Province based on microwave remote sensing and multi-model ensemble
KONG Yue, ZHANG Ke, SHEN Xiaoji, WANG Sheng, WANG Yuhao, TIAN Xinli, HE Meng, LIU Kuang, XIANG Zheng, FENG Ping
2025,53(6):75-81, 109
DOI: 10.3876/j.issn.1000-1980.2025.06.009
Abstract:
To accurately invert the soil moisture in Anhui Province and enhance the adaptability and accuracy of machine learning models, support vector regression, extreme gradient boosting, CatBoost, random forest, AdaBoost, and Stacking model (the first five machine learning models were selected as the base models, linear regression was used as the meta-model) were used to invert the soil moisture in Anhui Province. The spatial distribution and time series of soil moisture inversion results obtained from the Stacking model were analyzed. The results indicate that, with the same input remote sensing data, the Stacking model has higher accuracy and robustness compared to individual models. The correlation coefficient between the inverted soil moisture and the measured data reaches 0.72, and the root mean square error (RMSE) is 0.05 m3/m3. The spatial heterogeneity of soil moisture in Anhui Province is relatively high. The northern region is relatively dry, with an average soil moisture of around 0.2 m3/m3. The eastern areas of Chaohu Lake and the Yangtze River region are relatively humid, with an average soil moisture of up to 0.4 m3/m3. Although the Dabie Mountain area and the southern part of Anhui Province have higher altitudes, their soil moisture is still higher than that of the Huaibei Plain, indicating that the differences in climate between the north and the south may affect the magnitude of soil moisture. Overall, the spatial pattern of soil moisture in Anhui province is an increasing trend from the northwest to the southeast.
To accurately invert the soil moisture in Anhui Province and enhance the adaptability and accuracy of machine learning models, support vector regression, extreme gradient boosting, CatBoost, random forest, AdaBoost, and Stacking model (the first five machine learning models were selected as the base models, linear regression was used as the meta-model) were used to invert the soil moisture in Anhui Province. The spatial distribution and time series of soil moisture inversion results obtained from the Stacking model were analyzed. The results indicate that, with the same input remote sensing data, the Stacking model has higher accuracy and robustness compared to individual models. The correlation coefficient between the inverted soil moisture and the measured data reaches 0.72, and the root mean square error (RMSE) is 0.05 m3/m3. The spatial heterogeneity of soil moisture in Anhui Province is relatively high. The northern region is relatively dry, with an average soil moisture of around 0.2 m3/m3. The eastern areas of Chaohu Lake and the Yangtze River region are relatively humid, with an average soil moisture of up to 0.4 m3/m3. Although the Dabie Mountain area and the southern part of Anhui Province have higher altitudes, their soil moisture is still higher than that of the Huaibei Plain, indicating that the differences in climate between the north and the south may affect the magnitude of soil moisture. Overall, the spatial pattern of soil moisture in Anhui province is an increasing trend from the northwest to the southeast.
2025,53(6):82-89, 165
DOI: 10.3876/j.issn.1000-1980.2025.06.010
Abstract:
To quantitatively assess the fish-passing efficiency in the Laluo Fishway and identify its optimal environmental conditions, on-site observations of the flow field, water temperature, and number of passing fishes were conducted in the Laluo Fishway. A two-dimensional mathematical model of the Laluo Fishway was constructed and verified to obtain more detailed flow field data, and the diurnal and seasonal rhythms of fish-passing were analyzed. The results indicate that the Laluo Fishway experienced a fish-passing peak in April, May and July. Flow velocity is the key factor influencing fish-passing efficiency. The average flow velocity at the vertical slot between 74.8% and 81.2% of the target species wuimming speed is the most favorable condition for their upstrean migration. Water temperature is also identified as a significant factor, positively correlated with the upstream migration behavior of fishes. Futhermore, a significant threshold effect is observed with a recommendation to maintain water temperatures above 8℃. Additionally, Flow has a relatively small impact on fish behavior. A flow rate in the range of 0.4-0.8 m3/s is determined to be most favorable for fish-passing.
To quantitatively assess the fish-passing efficiency in the Laluo Fishway and identify its optimal environmental conditions, on-site observations of the flow field, water temperature, and number of passing fishes were conducted in the Laluo Fishway. A two-dimensional mathematical model of the Laluo Fishway was constructed and verified to obtain more detailed flow field data, and the diurnal and seasonal rhythms of fish-passing were analyzed. The results indicate that the Laluo Fishway experienced a fish-passing peak in April, May and July. Flow velocity is the key factor influencing fish-passing efficiency. The average flow velocity at the vertical slot between 74.8% and 81.2% of the target species wuimming speed is the most favorable condition for their upstrean migration. Water temperature is also identified as a significant factor, positively correlated with the upstream migration behavior of fishes. Futhermore, a significant threshold effect is observed with a recommendation to maintain water temperatures above 8℃. Additionally, Flow has a relatively small impact on fish behavior. A flow rate in the range of 0.4-0.8 m3/s is determined to be most favorable for fish-passing.
2025,53(6):90-100
DOI: 10.3876/j.issn.1000-1980.2025.06.011
Abstract:
To investigate the evolution characteristics of the air pocket during the geyser process, a numerical simulation of the release of an entrapped air pocket in a drainage pipe system under double-sided inflow conditions was conducted. The geyser formation mechanisms, air discharge characteristics, and air-water energy evolutions were analyzed. The results indicate that the entry and subsequent release of an entrapped air pocket into the vertical shaft trigger an air pocket-driven geyser, followed by the occurrence of a rapid-filling geyser. Depending on whether these two processes operate independently or interactively, the geyser process can be classified as either a separated type or a hybrid type. A higher dimensionless pipeline pressure difference P * or a smaller dimensionless initial air pocket volume V a* is more likely to trigger a hybrid geyser process. The air pocket discharge ratio during the air pocket-driven geyser is approximately 2%-47%; it first increases and then decreases with increasing P *, and it decreases with increasing V *a. The air pocket discharge ratio during a rapid-filling geyser is approximately 0-5%, and it is minimally affected by P * and V *a. During the geyser process, the peak kinetic energy of the air occurs in the air pocket-driven geyser stage, while the peak kinetic energy of the water in the vertical shaft occurs in the rapid-filling geyser stage. The geyser intensity decreases with increasing P * and increases with increasing V *a. An air pocket-driven geyser occurs when the dimensionless maximum kinetic energy of the air per unit mass exceeds 1.5; a rapid-filling geyser occurs when the dimensionless maximum kinetic energy of the water per unit mass exceeds 0.5.
To investigate the evolution characteristics of the air pocket during the geyser process, a numerical simulation of the release of an entrapped air pocket in a drainage pipe system under double-sided inflow conditions was conducted. The geyser formation mechanisms, air discharge characteristics, and air-water energy evolutions were analyzed. The results indicate that the entry and subsequent release of an entrapped air pocket into the vertical shaft trigger an air pocket-driven geyser, followed by the occurrence of a rapid-filling geyser. Depending on whether these two processes operate independently or interactively, the geyser process can be classified as either a separated type or a hybrid type. A higher dimensionless pipeline pressure difference P * or a smaller dimensionless initial air pocket volume V a* is more likely to trigger a hybrid geyser process. The air pocket discharge ratio during the air pocket-driven geyser is approximately 2%-47%; it first increases and then decreases with increasing P *, and it decreases with increasing V *a. The air pocket discharge ratio during a rapid-filling geyser is approximately 0-5%, and it is minimally affected by P * and V *a. During the geyser process, the peak kinetic energy of the air occurs in the air pocket-driven geyser stage, while the peak kinetic energy of the water in the vertical shaft occurs in the rapid-filling geyser stage. The geyser intensity decreases with increasing P * and increases with increasing V *a. An air pocket-driven geyser occurs when the dimensionless maximum kinetic energy of the air per unit mass exceeds 1.5; a rapid-filling geyser occurs when the dimensionless maximum kinetic energy of the water per unit mass exceeds 0.5.
2025,53(6):101-109
DOI: 10.3876/j.issn.1000-1980.2025.06.012
Abstract:
In order to fundamentally reduce the overtopping and failure rate of small earth-rockfill dams, a scaled-down model was established based on a small earth-rockfill dam project with an actual height of 15 m. The downstream slope protection was constructed using turf, cemented soil, and dry-laid stone masonry. The influence of different scour-resistant slope protection materials on the overtopping and failure process of the earth-rockfill dam was analyzed. The evolution law of breach shapes was studied, and in combination with the flow velocity and flow rate changes at the breach section, the effectiveness of different scour-resistant material-based downstream slope protection in resisting erosion damage was deeply explored. The experimental results show that under stable inflow conditions, the use of materials with high scour resistance, such as cemented soil and dry-laid stone masonry, in downstream slope protection significantly reduces the erosive force of overtopping water. This substantially extends the duration of overtopping and failure by 2-3 times. The maximum flow velocity at the breach is reduced by approximately 3%, while the maximum cross-sectional discharge decreases by a range of 10%-12%. In contrast, turf-based slope protection offers only modest delay in erosion damage, extending the breach duration by approximately one fold.
In order to fundamentally reduce the overtopping and failure rate of small earth-rockfill dams, a scaled-down model was established based on a small earth-rockfill dam project with an actual height of 15 m. The downstream slope protection was constructed using turf, cemented soil, and dry-laid stone masonry. The influence of different scour-resistant slope protection materials on the overtopping and failure process of the earth-rockfill dam was analyzed. The evolution law of breach shapes was studied, and in combination with the flow velocity and flow rate changes at the breach section, the effectiveness of different scour-resistant material-based downstream slope protection in resisting erosion damage was deeply explored. The experimental results show that under stable inflow conditions, the use of materials with high scour resistance, such as cemented soil and dry-laid stone masonry, in downstream slope protection significantly reduces the erosive force of overtopping water. This substantially extends the duration of overtopping and failure by 2-3 times. The maximum flow velocity at the breach is reduced by approximately 3%, while the maximum cross-sectional discharge decreases by a range of 10%-12%. In contrast, turf-based slope protection offers only modest delay in erosion damage, extending the breach duration by approximately one fold.
2025,53(6):110-118
DOI: 10.3876/j.issn.1000-1980.2025.06.013
Abstract:
To enhance the rapid response capability and operational stability of hydraulic generating units, a unit simulation model was established to investigate the damping characteristics, frequency characteristics, and stability under the novel power regulation mode of the governor derived from water turbine characteristic curves. Two improved strategies for the novel power regulation mode were developed. Results demonstrate that compared with conventional power regulation modes, the novel power regulation mode exhibits greater negative damping of the units, leading to inferior stability in small-grid operations but better frequency-modulated fast-acting in large-grid operations. Both the interpolation output control strategy and the guide vane speed control strategy can effectively suppress reverse regulation of power but both partially sacrifice the system’s primary frequency-modulated fast-acting. The guide vane speed control strategy shows superior suppression of reverse regulation of power, whereas the interpolation output control strategy offers better compatibility with other governor regulation functions.
To enhance the rapid response capability and operational stability of hydraulic generating units, a unit simulation model was established to investigate the damping characteristics, frequency characteristics, and stability under the novel power regulation mode of the governor derived from water turbine characteristic curves. Two improved strategies for the novel power regulation mode were developed. Results demonstrate that compared with conventional power regulation modes, the novel power regulation mode exhibits greater negative damping of the units, leading to inferior stability in small-grid operations but better frequency-modulated fast-acting in large-grid operations. Both the interpolation output control strategy and the guide vane speed control strategy can effectively suppress reverse regulation of power but both partially sacrifice the system’s primary frequency-modulated fast-acting. The guide vane speed control strategy shows superior suppression of reverse regulation of power, whereas the interpolation output control strategy offers better compatibility with other governor regulation functions.
2025,53(6):119-123, 157
DOI: 10.3876/j.issn.1000-1980.2025.06.014
Abstract:
To reveal the influence of free surface variation on the hydrodynamic loads of submarine pipelines with spiral strakes installed and verify the vortex-induced vibration (VIV) suppression effect of spiral strakes under partial detachment, hydrodynamic model tests were conducted on submarine pipelines equipped with spiral strakes. The tests investigated the changes in drag coefficient in the near-free-surface region (with a ratio of immersion depth to pipeline diameter is 1-4) and the near-false bottom region (with a ratio of bottom clearance to pipeline diameter is 1-4) under different Reynolds numbers. Additionally, the VIV suppression effect of spiral strakes was analyzed when 30% of their length was damaged.The test results show that when the submarine pipeline is immersed from a depth of four times the diameter to approaching the free surface, its drag coefficient gradually increases; when the submarine pipeline approaches the false bottom from an initial distance of four times the diameter, its drag coefficient decreases. With the increase in the Reynolds number, the suppression efficiency of VIV by the 30% damaged spiral strake exhibits a trend similar to that of the full-coverage scheme, both showing a decrease. Nevertheless, it still maintains a considerable suppression effect.
To reveal the influence of free surface variation on the hydrodynamic loads of submarine pipelines with spiral strakes installed and verify the vortex-induced vibration (VIV) suppression effect of spiral strakes under partial detachment, hydrodynamic model tests were conducted on submarine pipelines equipped with spiral strakes. The tests investigated the changes in drag coefficient in the near-free-surface region (with a ratio of immersion depth to pipeline diameter is 1-4) and the near-false bottom region (with a ratio of bottom clearance to pipeline diameter is 1-4) under different Reynolds numbers. Additionally, the VIV suppression effect of spiral strakes was analyzed when 30% of their length was damaged.The test results show that when the submarine pipeline is immersed from a depth of four times the diameter to approaching the free surface, its drag coefficient gradually increases; when the submarine pipeline approaches the false bottom from an initial distance of four times the diameter, its drag coefficient decreases. With the increase in the Reynolds number, the suppression efficiency of VIV by the 30% damaged spiral strake exhibits a trend similar to that of the full-coverage scheme, both showing a decrease. Nevertheless, it still maintains a considerable suppression effect.
2025,53(6):124-131
DOI: 10.3876/j.issn.1000-1980.2025.06.015
Abstract:
In order to enhance underwater image quality in turbid water environments, a polarization image restoration method for concrete structures in turbid water was proposed based on laboratory underwater imaging experiments. The polarization characteristic difference between the concrete’s structural information light and backscattered light was analyzed, and the Stokes vector was used to obtain the polarization parameter image of the underwater image. The contrast-limiting adaptive histogram equalization method was then employed to enhance image contrast. Finally, the underwater polarization imaging model was utilized to achieve image restoration. Comparative experiments against ten image processing methods demonstrate that in highly turbid sediment-laden water environments, the proposed method achieves improvement rates of 252%, 561%, 241%, and 93% for the four evaluation metrics: average gradient, entropy enhancement, underwater color image quality assessment, and underwater image quality measurement, respectively. This enables the acquisition of underwater images of apparent defects in concrete structures with high contrast and clear details, making it suitable for restoring underwater images of apparent defects in concrete structures.
In order to enhance underwater image quality in turbid water environments, a polarization image restoration method for concrete structures in turbid water was proposed based on laboratory underwater imaging experiments. The polarization characteristic difference between the concrete’s structural information light and backscattered light was analyzed, and the Stokes vector was used to obtain the polarization parameter image of the underwater image. The contrast-limiting adaptive histogram equalization method was then employed to enhance image contrast. Finally, the underwater polarization imaging model was utilized to achieve image restoration. Comparative experiments against ten image processing methods demonstrate that in highly turbid sediment-laden water environments, the proposed method achieves improvement rates of 252%, 561%, 241%, and 93% for the four evaluation metrics: average gradient, entropy enhancement, underwater color image quality assessment, and underwater image quality measurement, respectively. This enables the acquisition of underwater images of apparent defects in concrete structures with high contrast and clear details, making it suitable for restoring underwater images of apparent defects in concrete structures.
2025,53(6):132-137
DOI: 10.3876/j.issn.1000-1980.2025.06.016
Abstract:
Due to high residual stress at the stiffener welds on the web, shear link dampers (SLDs) are prone to fatigue damage under cyclic loading. Therefore, a new SLD with contact-type stiffeners was designed, and cyclic loading experiments were conducted to verify its hysteretic performance. The results indicate that the web shows premature out-of-plane buckling for the SLD without stiffeners, and cracks initiate early for the SLD with conventional welded stiffeners, which are detrimental to the low-cycle fatigue performance and energy dissipation capacity. In contrast, for the SLD with contact-type stiffeners, out-of-plane buckling of the web can be effectively suppressed, and residual stresse in the web caused by stiffener welds can be avoided. Consequently, the initiation and propagation of web cracks can be delayed, which significantly improves the low-cycle fatigue performance and energy dissipation capacity of the SLD.
Due to high residual stress at the stiffener welds on the web, shear link dampers (SLDs) are prone to fatigue damage under cyclic loading. Therefore, a new SLD with contact-type stiffeners was designed, and cyclic loading experiments were conducted to verify its hysteretic performance. The results indicate that the web shows premature out-of-plane buckling for the SLD without stiffeners, and cracks initiate early for the SLD with conventional welded stiffeners, which are detrimental to the low-cycle fatigue performance and energy dissipation capacity. In contrast, for the SLD with contact-type stiffeners, out-of-plane buckling of the web can be effectively suppressed, and residual stresse in the web caused by stiffener welds can be avoided. Consequently, the initiation and propagation of web cracks can be delayed, which significantly improves the low-cycle fatigue performance and energy dissipation capacity of the SLD.
2025,53(6):138-146
DOI: 10.3876/j.issn.1000-1980.2025.06.017
Abstract:
The shear capacity formula for deep flexural members in Appendix G of GB/T.50010-2010 Code for Design of Concrete Structures , namely the GB/T50010 formula, does not account for the influence of openings and thus cannot be accurately applied to the design of deep beams with square openings. To address this issue, the calculation method for the shear capacity of deep beams with square openings was investigated. Based on the statistical analysis of relevant test data to evaluate the reliability of the traditional method, the ultimate bearing capacity of nine groups of members was compared through nonlinear finite element simulation. The influence of opening parameters on the force performance was analyzed. At the same time, the modified formula of the GB/T50010 formula was given by using the fitting method, and the applicability of the modified formula was verified. The results indicate that the traditional empirical reinforcement method, which involves adding additional reinforcement around openings, lacks sufficient reliability. For a deep beam with square openings, the reduction in shear capacity is primarily governed by the opening position and opening ratio. Specifically, shorter vertical distances from the opening centroid to the compressive path (i.e., the line connecting the loading point and the support) and a larger opening ratio correlate with a decrease in the member’s shear capacity. Moreover, the opening behavior mainly reduces the contribution of concrete to the shear capacity of the member; the modified formula, by adjusting the concrete’s shear contribution term, can fully consider the adverse effects of single or double openings. Within a defined range of opening sizes and positions, the modified formula significantly improves the prediction accuracy of the shear capacity of a deep beam with openings.
The shear capacity formula for deep flexural members in Appendix G of GB/T.50010-2010 Code for Design of Concrete Structures , namely the GB/T50010 formula, does not account for the influence of openings and thus cannot be accurately applied to the design of deep beams with square openings. To address this issue, the calculation method for the shear capacity of deep beams with square openings was investigated. Based on the statistical analysis of relevant test data to evaluate the reliability of the traditional method, the ultimate bearing capacity of nine groups of members was compared through nonlinear finite element simulation. The influence of opening parameters on the force performance was analyzed. At the same time, the modified formula of the GB/T50010 formula was given by using the fitting method, and the applicability of the modified formula was verified. The results indicate that the traditional empirical reinforcement method, which involves adding additional reinforcement around openings, lacks sufficient reliability. For a deep beam with square openings, the reduction in shear capacity is primarily governed by the opening position and opening ratio. Specifically, shorter vertical distances from the opening centroid to the compressive path (i.e., the line connecting the loading point and the support) and a larger opening ratio correlate with a decrease in the member’s shear capacity. Moreover, the opening behavior mainly reduces the contribution of concrete to the shear capacity of the member; the modified formula, by adjusting the concrete’s shear contribution term, can fully consider the adverse effects of single or double openings. Within a defined range of opening sizes and positions, the modified formula significantly improves the prediction accuracy of the shear capacity of a deep beam with openings.
2025,53(6):147-157
DOI: 10.3876/j.issn.1000-1980.2025.06.018
Abstract:
Shallow cohesive soil interacts strongly with the atmospheric environment, and its engineering properties deteriorate severely due to the influence of climate factors, leading to geological disasters and ecological environmental problems. In response to the above issues, a combination of bio-glue and rice straw fiber was introduced to improve the mechanical properties of cohesive soil. Through unconfined compressive strength tests and direct shear tests, the changes in the unconfined compressive strength characteristics and shear strength parameters of soil with single admixture and composites were investigated. The effects of bio-glue and fiber contents on the improvement effect of composite treatment were studied, and the effect mechanism of bio-glue and straw fiber composite modified cohesive soil was analyzed based on scanning electron microscope (SEM). The results show that due to the increase in bio-glue content and fiber content, the stress-strain curves of modified soil tend to behave as strain hardening, with a prolonged peak position and reduced post-peak stress decay. Both unconfined compressive strength and shear strength of modified soil are significantly enhanced, which mainly enhances the soil’s mechanical properties by increasing cohesion and has little effect on the internal friction angle. Bio-glue improves soil structure through surface coating, particle bonding, and pore filling, which also improves the reinforcement effect of fiber-soil interface and enhances soil’s mechanical properties by combining the network framework formed by fibers.
Shallow cohesive soil interacts strongly with the atmospheric environment, and its engineering properties deteriorate severely due to the influence of climate factors, leading to geological disasters and ecological environmental problems. In response to the above issues, a combination of bio-glue and rice straw fiber was introduced to improve the mechanical properties of cohesive soil. Through unconfined compressive strength tests and direct shear tests, the changes in the unconfined compressive strength characteristics and shear strength parameters of soil with single admixture and composites were investigated. The effects of bio-glue and fiber contents on the improvement effect of composite treatment were studied, and the effect mechanism of bio-glue and straw fiber composite modified cohesive soil was analyzed based on scanning electron microscope (SEM). The results show that due to the increase in bio-glue content and fiber content, the stress-strain curves of modified soil tend to behave as strain hardening, with a prolonged peak position and reduced post-peak stress decay. Both unconfined compressive strength and shear strength of modified soil are significantly enhanced, which mainly enhances the soil’s mechanical properties by increasing cohesion and has little effect on the internal friction angle. Bio-glue improves soil structure through surface coating, particle bonding, and pore filling, which also improves the reinforcement effect of fiber-soil interface and enhances soil’s mechanical properties by combining the network framework formed by fibers.
2025,53(6):158-165
DOI: 10.3876/j.issn.1000-1980.2025.06.019
Abstract:
To address the issues of low land resource utilization efficiency in cable trench installation and poor heat dissipation in conduit trench installation, a magnetic-thermal-current multiphysics coupled finite element simulation model of a 110 kV cross-linked polyethylene cable was constructed. The current carrying capacity of both the cable trench and the conduit trench installation methods was simulated and calculated. The effects of three methods, laying concrete outside the conduit in the conduit trench installation method, using high thermal conductivity conduits, and adding backfill materials inside the conduit, on increasing the current carrying capacity of the cable were investigated. Based on the orthogonal experiment, the backfill material was improved to obtain the optimal ratio of the backfill material. The research results show that by pouring concrete outside the high thermal conductivity conduits and adding improved backfill materials with the optimal proportion inside the conduit, the current carrying capacity of the cable can be significantly enhanced. Compared with the cable trench installation method, this approach increases single-circuit capacity by 31.64% and dual-circuit capacity by 18.49%.
To address the issues of low land resource utilization efficiency in cable trench installation and poor heat dissipation in conduit trench installation, a magnetic-thermal-current multiphysics coupled finite element simulation model of a 110 kV cross-linked polyethylene cable was constructed. The current carrying capacity of both the cable trench and the conduit trench installation methods was simulated and calculated. The effects of three methods, laying concrete outside the conduit in the conduit trench installation method, using high thermal conductivity conduits, and adding backfill materials inside the conduit, on increasing the current carrying capacity of the cable were investigated. Based on the orthogonal experiment, the backfill material was improved to obtain the optimal ratio of the backfill material. The research results show that by pouring concrete outside the high thermal conductivity conduits and adding improved backfill materials with the optimal proportion inside the conduit, the current carrying capacity of the cable can be significantly enhanced. Compared with the cable trench installation method, this approach increases single-circuit capacity by 31.64% and dual-circuit capacity by 18.49%.
2025,53(6):166-174
DOI: 10.3876/j.issn.1000-1980.2025.06.020
Abstract:
To address the issue that directly using historical datasets as input in photovoltaic (PV) power prediction models struggles to meet the required prediction accuracy, a short-term PV power prediction model, namely CSSA-LSTM model was proposed based on time-segmented convolutional dynamic time warping (CDTW) for similar day selection and the chaotic sparrow search algorithm (CSSA) for long short-term memory (LSTM) optimization. After preprocessing the data, the model identified key meteorological factors affecting power generation through Pearson correlation analysis, thereby avoiding interference from irrelevant data. It then divided time periods based on the total solar radiation sequence of the day to be predicted, applied the CDTW algorithm to each time period for selecting similar time segments, and reconstructed these segments into a set of similar days. Meanwhile, CSSA was used to optimize the hyperparameters of the LSTM model, enabling adaptive search for the optimal hyperparameters. Simulation analysis results using measured data from 2021 of a PV power station in southern China show that compared with traditional similar day methods and LSTM models optimized by the sparrow search algorithm (SSA), the similar day selection method and CSSA-LSTM model proposed in this study exhibit higher prediction accuracy and robustness.
To address the issue that directly using historical datasets as input in photovoltaic (PV) power prediction models struggles to meet the required prediction accuracy, a short-term PV power prediction model, namely CSSA-LSTM model was proposed based on time-segmented convolutional dynamic time warping (CDTW) for similar day selection and the chaotic sparrow search algorithm (CSSA) for long short-term memory (LSTM) optimization. After preprocessing the data, the model identified key meteorological factors affecting power generation through Pearson correlation analysis, thereby avoiding interference from irrelevant data. It then divided time periods based on the total solar radiation sequence of the day to be predicted, applied the CDTW algorithm to each time period for selecting similar time segments, and reconstructed these segments into a set of similar days. Meanwhile, CSSA was used to optimize the hyperparameters of the LSTM model, enabling adaptive search for the optimal hyperparameters. Simulation analysis results using measured data from 2021 of a PV power station in southern China show that compared with traditional similar day methods and LSTM models optimized by the sparrow search algorithm (SSA), the similar day selection method and CSSA-LSTM model proposed in this study exhibit higher prediction accuracy and robustness.
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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
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.
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(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.
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(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.
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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