In order to solve the frequency safety problem caused by the large-scale access of renewable energy, adjustable-speed pumped storage unit (ASPSU) was involved in frequency regulation of new power system. Firstly, the AGC frequency regulation stability of ASPSU was analyzed through the root locus method. Then, the evaluation scheme of unit power command response performance was designed to measure the rapidity and accuracy of output of ASPSU. And on this basis, the active power dynamic optimization allocation strategy based on the rate of change of frequency (ROCOF) was proposed. The new energy disturbance was simulated in the LFC model of a two-area interconnected power system to verify the effectiveness of proposed strategy. The results show that the proposed active power dynamic optimization allocation strategy can give full play to the frequency regulation advantage of ASPSU, effectively prevent frequency exceedance and maintain the frequency stability of power system.

In order to realize the prediction of industrial water consumption and improve the prediction accuracy, a mixed strategy was introduced to optimize the sparrow search algorithm (SSA) for improving the global search ability. The improved sparrow search algorithm (ISSA) was used to optimize the parameters of support vector machine (SVM). A support vector machine model (ISSA-SVM) based on hybrid strategy and ISSA was established, and the prediction of industrial water consumption in Ningxia was taken as an example. The results show that the ISSA-SVM model has the characteristics of fast optimization speed and high precision, and it has good applicability and feasibility in industrial water consumption prediction.

The weir-gate structure has larger discharge capacity. To accurately and efficiently check the discharge of weir-gate, three intelligent algorithms including BP neural network, SVM and GRNN were used to predict the discharge coefficient of cylindrical weir-gate. The correlation analysis and variation law between dimensionless parameters and discharge coefficient were discussed. The results show that the GRNN and the BP can accurately predict the discharge coefficient of the cylindrical weir-gate. The determination coefficient of the BP in the test stage is 0.997, the root mean square error is 0.009, the average absolute percentage is 0.801 %, and the Nash efficiency coefficient is 0.997, which is superior to the GRNN, and it can be used as an efficient and high-precision prediction model for the discharge coefficient of the weir-gate. There is a stronger correlation between the ratio of gate opening to cylinder diameter (a/D), the ratio of weir head to cylinder diameter (H_w/D) and C_d. The C_d increased with the increase of upstream Froude number (Fr) and H_w/D, and the greater the a/D is, the greater the increase of C_d is. The search results provide theoretical reference and technical support for the popularization and application of cylindrical weir gate in practical engineering.

In view of the problem of rapid durability deterioration and the service reliability reduction of concrete structure caused by saline ions erosion and freeze-thaw coupling in cold and drought irrigation area in northwest China, based on the rapid indoor freeze-thaw test, mechanical property change of clean water, 3%NaCl solution, 5%Na₂SO₄ solution was studied in the process of freeze-thaw. The freeze-thaw damage model was established to analyze the damage degree of relative dynamic elastic modulus of concrete block for three kinds of freeze-thaw mediums. The Weibull life prediction model was used to predict the life of test specimen. The results show that the mass loss, compressive strength and dynamic elastic modulus of the concrete mass damage sizes are 3%NaCl> 5%Na₂SO₄ > clean water; According to Weibull life prediction model, the fitting parameters b and C were obtained, and the correlation coefficient R₂ is above 0.9; The prediction results of model life are consistent with the mechanical performance test results at different operating conditions; The mass loss, compressive strength and dynamic elastic modulus life prediction of concrete under three freeze-thaw mediums are clear water> 5% Na₂SO₄>₃% NaCl. It can be seen that in the environment of freezing-melting and thawing erosion, $\text{SO}^{2-}_4$ erosion degree is greater than Cl^- erosion, and the clean water erosion degree is minimal. The research results can provide a theoretical basis for the mechanical performance characteristics research and later maintenance of concrete in cold and drought irrigation areas.

During the excavation of the construction adit, the Jiangmen Neutrino Underground Laboratory revealed three long and water rich cracks, and high-pressure jet water gushing appeared in local water exploration holes, which may have adverse effects on the stability of the surrounding rock of the tunnel. The influence of L1, L2, L3 on the deformation of surrounding rock of the experimental hall under different water pressures of the excavation face was systematically analyzed by using the discrete element method. The results show that the influence of water rich long cracks on the overall stability of the arch surrounding rock is small. The arch surrounding rock at L1 and L2 is not sensitive to the change of the drainage conditions of the excavation face. With the increase of the water pressure of the excavation face, the deformation of L3 arch shoulder increases sharply and the trend is not convergent. L2 has little effect on the deformation of the lower pool, and the shallow surrounding rock near L1 and L3 is obviously unloaded. Based on comprehensive analysis, 0.5 MPa is recommended as the control standard for shallow surrounding rock drainage at the excavation face of this project.

Simulation and prediction of runoff under climate change and land use scenarios are of great significance for the study of water balance and water resources planning and management. Taking the Qingshui River Basin in Zhangjiakou City as the research area, the global climate model GFDL-ESM2M and CA-Markov model were used to analyze and predict the meteorological data and land use in the Qingshui River basin, and the SWAT hydrological model was constructed to quantify the changes of water balance factors in the basin in 2025 under the joint influence of climate change and land use. The results show that under the three GHG emission scenarios, the rainfall in Qingshui River Basin increased significantly in 2025, the maximum temperature and average temperature under the RCP2.6 emission scenario decreased compared with 2015; The maximum temperature and average temperature under the RCP4.5 and RCP8.5 emission scenario increased, and the minimum temperature under the three scenarios decreased. From 2015 to 2025, arable land, woodland, grassland, water area and construction land changed by -6.24 %, -0.86%, 6.32%, 0.20% and 0.59%, respectively. Compared with 2014-2015, the water balance distribution of the watershed changed in 2025, and the peak monthly runoff occurred from July to September. The average annual runoff under the three discharge scenarios were 4.40 m³/s, 5.84 m³/s and 9.94 m³/s, respectively.

In order to accurately grasp the actual operation of the governor of hydropower units, this paper proposed a multi-dimensional verification method of the governor operation data of hydropower units based on correlation analysis. The multi-dimensional correlation verification architecture was constructed to process the multi-dimensional operation data of the unit governor. The correlation analysis method was used to calculate the correlation degree between the multi-dimensional operation data change sequences, and the anomaly identification of the multi-dimensional operation data was completed by judging the range of the correlation degree. Based on the characteristics of the identified abnormal data, abnormal data reconstruction was completed from three dimensions of single point, multi-point and continuous abnormal data respectively to achieve multi-dimensional verification of governor operation data of hydropower units. The experiment shows that the method can effectively identify the abnormal data, reconstruct the missing data, reduce the abnormal rate of data through verification, and improve the availability of the governor operation data of hydropower units.

To scientifically evaluate the eutrophication degree of water bodies, based on the comparison and analysis of various eutrophication evaluation methods, convolutional neural network (CNN) was introduced to establish the convolutional-eutrophication (CNN-E) model. Based on the monthly-scale water quality and algae monitoring data of Honghu Lake from 2014 to 2019, the comprehensive nutrient index method, BP neural network method and CNN-E model were used to evaluate its eutrophication degree. The mean absolute error, root mean square error, coefficient of determination and Nash-Sutcliffe efficiency coefficient were used to evaluate the performance of the neural network model. The results show that Hong Lake was in a mild eutrophic state for a long time, and the eutrophication level was increasing. In terms of model performance, the four evaluation indexes of CNN-E model are better than BP neural network 0.166, 0.098, 0.078 and 0.087, respectively. The CNN-E model can provide technical support for the prevention and comprehensive management of eutrophication in lake water bodies.

In order to explore the solution to the risk of ponding and waterlogging in the sub-catchment area during sponge city design, SWMM modeling was used to study the peak runoff control characteristics of LID facilities and their combinations under different recurrence interval, as well as the peak runoff control laws of the incremental scale of volumetric LID facilities. The study shows that the peak runoff control effect of volumetric LID facilities is mainly achieved through peak time delay, while the peak runoff control effect of permeable LID facilities is mainly achieved through overall runoff reduction, and the peak runoff control effect of volumetric LID facilities is more significant; Only the combination of permeable LID facilities cannot significantly reduce peak runoff and delay peak time on a rainfall event with a recurrence interval of 5 years or more. When combined with volumetric LID facilities, it can achieve a peak runoff reduction rate of over 20% for rainfall with a recurrence interval of less than 10 years; When the scale of permeable LID facilities increases by 60% or more, the peak runoff reduction effect is more obvious for rainfall with a recurrence interval of 50 years or less; When its scale increases by 80% or more, it can basically ensure that the total runoff volume of post-development does not exceed which of pre-development with a recurrence interval of 50 years or less. The research results are aimed at exploring solutions to the risk of ponding and waterlogging in local areas, which provides theoretical reference for the design of peak runoff control in actual sponge city sub-catchments.

Based on the daily precipitation data of 135 weather stations from the Yangtze river delta city during 1951-2017, spatio-temporal patterns of the extreme precipitation of the Yangtze river delta agglomeration were analyzed by the linear trend analysis, M-K trend test, wavelet cycle analysis and reverse distance weight interpolation methods. The extreme precipitation indexes were defined from the aspects of extreme precipitation amount, frequency, and intensity. The results show that except for a decrease in the continuous drought index of -0.11 d/a, the extreme precipitation indexes showed an increasing trend. The average period of change in extreme precipitation indicators was in the range of 15 a and 25 a, and the characteristic timescale was 40-50 a; The high-value area of the annual mean spatial distribution of maximum daily precipitation, maximum daily precipitation, continuous moisture index, strong rainfall, heavy rain days and annual rainy day precipitation presented in the southeast areas of the Yangtze River Delta urban agglomeration, which were distributed the opposite parts to the persistent drought index. However, the high-value areas of ordinary daily precipitation intensity were in the western part of the Yangtze River Delta urban agglomeration; The high-value areas of the changing trends of the spatial distribution and the maximum precipitation in the Yangtze River Delta urban agglomeration were all in Nanjing, Zhenjiang, Changzhou and Shanghai. The high-value areas of the spatial distribution change trend of ordinary daily precipitation intensity and annual rainy daily precipitation change trend were in Nanjing, Wuxi and Suzhou. The high-value areas of continuous moisture index, continuous drought index and heavy rain days were all in Hangzhou, Shaoxing and Wenzhou. The research findings can provide references for the prevention of rainstorm waterlogging disasters in the Yangtze River Delta Urban Agglomeration.