To study the trend of runoff evolution under the influence of climate change and human activities, the Qinhuai River Basin was taken as the research area based on the hydrometeorological data of representative stations. Firstly, the Mann-Kendall method was used to study the variation trend of hydrometeorological elements in the basin. Secondly, the abrupt change points of the runoff series were discussed by orderly cluster method and double cumulative curve method. Thirdly, the key factors affecting runoff were screened from numerous hydrometeorological factors, and the Wavelet Analysis-BP neural network coupling model was established to predict the runoff. Finally, attribution analysis method was used to identify contribution of climate change and human activities to the runoff variation. The results show that the rainfall of the Xinhe river sluice presents a downward trend, while the Wudingmen sluice and the whole basin show an upward trend, but none of the trends were significant. The runoff of the basin shows an upward trend, and the increase trend of Xinhe river sluice is not significant, both the Wudingmen sluice and the whole basin increase trend pass the test of 0.01 confidence level, and the annual evaporation tends to decrease. There is a great consistency between the Wudingmen sluice and the whole basin in the variation trend of rainfall, runoff, and the time of abrupt change point. The contribution rates of human activities and climate change to runoff increase were 73.92% and 26.08%, respectively, the human activities were an important factor that led to the runoff variation. The conclusion provides a scientific basis for flood and drought prevention and water resources planning in this basin.

In order to analyze the influence of Poyang Lake Water Control Project on wetland vegetation habitat, MIKE21 was used to establish two-dimensional hydrodynamic model of Poyang Lake. Through the scenario of the typical years, the changes of water level and wetland vegetation growth habitat area in the main lake area and wetland nature reserve after the operation of the water conservancy project were simulated. The simulation results show that the operation of the Hydraulic Project has a great influence on the water level in the north of Songmen Mountain, and the influence degree gradually decreases from north to south. The operation of the hub has a great influence on the most suitable area and suitable habitat area of wetland vegetation in different hydrological years. The vegetation habitat surface varies greatly. After the operation of the hub, the dry year increases by 43.8 %, the normal year increases by 24.6 %, and the wet year is only 16.4 %. In October and November, the suitable habitat area can reach more than 2,000 km², accounting for about 2/3 of the total lake area, indicating that wetland vegetation will provide Siberian cranes with rich food sources and make them better survive and reproduce in wetlands. The simulation results reveal the influence of the Hydraulic Project on the change law of lake water level and wetland vegetation habitat interval under the current scheduling scheme, which can provide a theoretical reference for engineering construction and dispatching operation and maintenance.

The primary frequency modulation function of the hydropower unit plays an increasingly important role in maintaining the safe and stable operation of the power grid, and it is necessary to ensure that the units integrated into the power grid have good primary frequency modulation performance. The influence of various dead zone nonlinear factors in the hydraulic turbine adjustment system on the dynamic performance of primary frequency modulation cannot be ignored. The nonlinearity of the dead zone in all links of the adjustment system is comprehensively analyzed. Based on the established high-precision primary frequency modulation model of hydropower units, the influence of frequency dead zone, openness dead zone, power dead zone and dead zone of the follow-up system on the performance of the primary frequency modulation response performance of large and small frequency difference is explored, and it is emphasized that the next frequency modulation inaction of small disturbances may be related to the dead zone of the follow-up system, which provides important theoretical guidance for the improvement and optimization of the primary frequency modulation function of the hydropower unit.

The geological conditions of a certain reservoir area and dam site are complex, with multiple penetrating faults. In order to analyze the seepage situation in the reservoir area and the dam body, the finite element method was used to conduct three-dimensional numerical simulation of the seepage field in the dam and reservoir area. Based on the actual operating conditions, parameter inversion was conducted, and the anti-seepage safety of the dam was analyzed and evaluated based on the distribution of water head and the calculation results of seepage flow. The results indicate that the change of permeability coefficient of faults in the reservoir area has the most significant impact on the seepage flow rate of the left bank and dam section, and the left bank seepage is more severe. The seepage line of the dam body is relatively high, and there are cracks in the upstream anti-seepage panel, causing jet flow in the high water level dam body. There is a lot of accumulated water in the corridor, and the comprehensive anti-seepage and drainage system facilities of the dam are not perfect. The overall seepage flow in the dam site area is too large, especially in the thin watershed on the left bank, where leakage is more severe. There are serious problems with dam foundation leakage and seepage around the dam, and it should be treated.

In the hydraulic model test of the CB hydroelectric station in Jinsha River, occasional penetrating vortexes were observed in front of the sluice gate. In order to eliminate the vortex, this paper improved a vertical eddy-eliminating barries and proposed a new horizontal eddy-eliminating barries. The flow field in front of the sluice gate, vortex scale, and vortex generation frequency of the new horizontal eddy-eliminating barries were measured and analyzed for its vortex elimination effect. The results show that the proposed horizontal eddy-eliminating barries has better vortex elimination effect than the previous vertical eddy-eliminating barries, and it is a low-cost and efficient vortex elimination facility for sluice gate.

Dam displacement can directly affect the quality and operation safety of the dam. To find out the prediction model of the dam displacement, the temporal convolutional neural network model was used to predict the dam displacement. Three bionic algorithms of the sparrow search algorithm (SSA), the gray wolf algorithm (GWO) and the bat algorithm (BA) were improved by genetic algorithm, and three optimization algorithms including MSSA, MGWO and MBA were obtained. Taking root mean square error, determination coefficient, mean absolute error, efficiency coefficient and GPI index as precision index system, three combined weighted models including D-MSSA-TCN, D-MGWO-TCN and DMBA-TCN were constructed based on the deep belief network model (DBN). The results show that the MSSA algorithm had the highest operating efficiency and accuracy among all the algorithms. The accuracy of the three combined models was significantly higher than the rest of the models. The D-MSSA-TCN model had the highest accuracy among all models and can be recommended for estimating dam displacement.

In recent years, part of water conveyance buildings of the main canal of the middle route of the South-to-North Water Diversion project have high water level and abnormal flow pattern, which lead to the risk of reduced water conveyance capacity. Therefore, it is urgent to assess the head loss. However, there are no monitoring stations inside the buildings, the project operation has not reached the designed scale, and the monitoring data lacks verification. The monitoring data of water level and discharge of the main canal during the large water delivery period in 2022 were collected, and the third-party hydraulic prototype measurement was carried out, and the monitoring data was reviewed and corrected. A calculation method of head loss was put forward using comprehensive head loss coefficient. The head loss of 143 out of 158 water transport structures in the main canal was calculated under enlarged flow. The results show that there is surplus in the distribution of head in the main canal. The total surplus head of the whole line is 3.05 m, among which the surplus in the section south to the Yellow River, the section between the Yellow River and the Zhang River, the section north to the Zhang River are 0.48 m, 1.06 m and 1.51 m respectively, accounting for 4%, 13% and 12% of the allocated head, respectively. The head loss of 40 water conveyance buildings exceeded the assigned value, among which were 31 inverted siphon, 4 aqueduct, 4 culvert and 1 tunnel.

At present, the TV card model of PSD-PBA platform used in power system stability calculation cannot reflect the difference of units under multiple water heads, which is specifically reflected its dynamic response speed and anti-regulation accuracy. Based on the TV card model, an improved scheme is proposed. The water head-opening-power characteristics and power T_w characteristics of the model are obtained by program processing with the early operation data of the hydropower station, and then added to the improved model successively. The results show that the dynamic characteristics of the TV card model do not have the conditions for multi-parameter identification under the power mode primary frequency modulation. Moreover, the accuracy of anti-regulation under different loads is poor. The response characteristics of the improved model accord with the operation law of the real machine and can accommodate the difference of multiple water heads of the unit.

In order to solve the upstream demand of small fish with weak swimming ability in the vertical slot fishway, an anti-flow cylinder is added to the migration channel between the long and short baffles. Hydro 3D open source code and LES-based numerical simulation technology are used to simulate the flow field in the vertical slot fishway before and after the anti-flow cylinder is added. According to the streamline distribution in the time-averaged flow field, the results show that the area of the vortex area in the pool is reduced after adding the blocking cylinder, which solves the problem of lack of sense of direction in the process of fish upstream in the traditional vertical slot fishway. The turbulent kinetic energy in the pool increases by 20%, which raised the energy dissipation of the water flow and reduced the energy consumption during the fish upstream process. The increase of vorticity around the long and short baffles and the blocking cylinder may have an adverse effect on the stability of the fish during swimming. However, according to the vortex structure, the vortex diameter behind the blocking cylinder is less than 76% of the body length of the small fish, so it has little impact on the stability of the fish during swimming. In summary, the setting of a flow blocking cylinder in the vertical slit fishway can improve the success rate of small fish upstream.

To prompt grouting construction quality management of Wuyue Pumped Storage Power Station, combining with exposed geological conditions after excavation, designed grouting parameters, this paper conducts grouting test, and determines the grouting process parameters. The introduction of intelligent grouting system can reduce labor intensity of workers and the labor cost, and improve the traceability of quality work, save the construction period. The introduction of third-party testing units brings advanced technology and management experience, and improves the credibility of testing results. Using the results of water pressure test and comparative analysis of wave velocities of different types of rock masses can evaluate the grouting quality. The evaluation results are mutually verified, which improves the persuasiveness of the grouting effect. The grouting project has achieved satisfactory results for all parties involved in the construction, and this grouting construction process management experience can be a reference for similar projects.