In order to solve the problem of interval flow inversion of cascade hydropower stations, taking the cascade hydropower stations in the middle and lower reaches of the Dadu River basin as an example, the characteristic curve correction of the six reservoirs in the basin was carried out. In order to accurately calculate the inflow and outflow of each reservoir by correcting each characteristic curve, and make the flow inversion rate of each interval meet the requirements, four correction methods of characteristic curve correction methods were proposed with the goal of minimizing the flow inversion rate, which includes single-point discrete optimization, multi-point discrete optimization, curve cluster overall translation optimization, and distinguishing different water head/water level translation optimization. The simulation calculation shows that although each curve correction method has certain effect, the distinguishing different water head/water level translation optimization method has the best effect. After using this method to correct the characteristic curve, the interval flow inversion rates of PuSheng and GongTong decreased from 53% and 77.96% to 13.93% and 4.37%, respectively. Although the flow inversion rates in the remaining intervals has slightly increased after correction, they are all within a reasonable range. It can be seen that the curve correction method effectively reduces the inversion rate of interval flow and improves the consistency of runoff series, which can provide a data basis for the accurate water regulation of cascade hydropower stations in the Dadu River basin.

Water environment safety has always been an important issue that plagues the healthy development of country's social economy. Low-impact development technologies have good resilience in dealing with water environment safety issues. Taking Cangzhou China-Europe Green Industrial Park as the research object, the rainstorm flood model and the rainwater resource utilization benefit model were established. The study found that green roofs have an obvious control effect on ground runoff. The reduction rate and control rate of the total runoff are 56.31% and 68.32%, respectively, and the peak flow reduction rate is 48.58%. The control rate for pollutants of TP, TN, SS and COD is 72.92%, 74.82%, 74.44% and 73.89%, respectively. However, with the increase of rainfall intensity, the runoff control rate and the pollutant concentration control rate decreased, showing a significant negative correlation between the fourth and fifth power functions. After calculation, green roof can produce better economic and environmental benefits.

In recent years, rainstorm and flood disasters occur frequently in the basin. Accurate and reliable flood forecasting is an important measure to effectively prevent and resist mountain torrents. Taking Lushui basin as the research area, this paper constructed the HSPF semi-distributed model. Choosing the representative floods in the flood data of the basin from 2013 to 2020, the calibration and verification of the model parameters were carried out. The accuracy of flood simulation was evaluated by using indexes of certainty coefficient and relative error. The results show that the model has a good performance in the field flood simulation of Lushui basin. The qualified rates of peak time and peak discharge of 15 flood simulations are 100.0% and 80.0%, respectively, the qualified rates of flood volume and runoff depth are 93.3%, and the average value of certainty coefficient is 0.80. The overall prediction accuracy reaches class B, indicating that the HSPF flood prediction model has good applicability in Lushui basin. The research results can provide basis for flood forecasting in this area.

Based on the climatic conditions and flood characteristics of the Puhe River Basin, this paper used Tank model to simulate 10 rainstorm flood processes in the basin from 2019 to 2020, constructed a conceptual rainstorm flood meteorological risk early warning model suitable for the basin, and carried out simulation and accuracy evaluation. The results show that the improved water tank model can intuitively simulate the water level change process curve of Shijiao hydrological station under different time scales and different basic water levels, reduce the uncertainty of area rainfall threshold, and the prediction accuracy is class B; Meteorological risk warning is issued level by level according to the simulation results, and the skill score and hit rate are 100%; The average early warning release time is more than 3 hours in advance, which can be substituted into the predicted precipitation to further extend the flood forecast period.

Pumped storage power station is the most mature large-scale energy storage tool in power systems. Because of its flexible peak and frequency modulation performance, it plays an important role in the novel power systems with new energy as the main body. The selection of upper and lower reservoirs is the key factor to determine its energy storage capacity and investment benefit in the process of site selection of pumped storage power station. However, the traditional site selection method of manual site investigation has the problems of heavy workload, low efficiency and easy leakage. In this paper, a method for site selection of upper and lower reservoirs of pumped storage power station based on satellite remote sensing terrain data was proposed, and experimental verification was carried out by Jinyun pumped storage power station in Zhejiang Province. The results show that the possible upper and lower reservoir construction areas within the target area can be efficiently screened out by using satellite remote sensing terrain data and computational intelligence techniques, which greatly improves the efficiency of site selection and shows the great application potential of satellite remote sensing in site selection of pumped storage power station.

In the design scheme of asphalt concrete core rockfill dam, the axis of diaphragm of dam foundation and asphalt concrete core wall is overlapped. However, due to construction errors and other reasons, the axis of diaphragm of dam foundation and asphalt concrete core wall may not be completely overlapped. Based on the finite element analysis method, the stress behavior of diaphragm of dam foundation and asphalt concrete core wall under different offsets was studied. The results show that under the superposition of axes, the local tensile stress of the diaphragm of dam foundation is in a state of no or small in the construction period and operation period, which has little influence on the whole. The minor offset of the axis of the diaphragm of dam foundation to the downstream will have a certain adverse effect on the stress of the diaphragm of dam foundation during operation. The main performance is that the local tensile stress of the downstream face of the diaphragm of dam foundation increases, and there is stress concentration. The local tensile stress increases by 3.6 times compared with that without offset. The concrete base of the asphalt concrete core wall can be slightly extended to the downstream according to the offset of the diaphragm of dam foundation, which can reduce the local tensile stress of the downstream surface of the diaphragm of dam foundation by 59.3 % and weaken the stress concentration, so as to improve the stress state of the diaphragm of dam foundation. The finite element simulation analysis can provide support for safety evaluation and selection of engineering treatment measures under eccentric condition of diaphram of dam foundation.

Due to the frequent storage and discharge cycle of the reservoir, the cushion of the face rockfill dam of pumped storage power station should have good drainage performance, but when the face slab appears cracks, the cushion with low fine particle content may have the problem of seepage stability. Taking the concrete face rockfill dam of a pumped storage power station as an example, the inverted filtration test and seepage calculation and analysis were carried out, focusing on the filter protection mechanism of cushion material and transition material. The allowable crack width of the face slab was determined according to the damage slope of cushion material. The results show that after properly optimizing the fine particle content of cushion and transition material, the requirements of inverted filtration criterion can be met, and the allowable crack width of the panel is increased by 30% on the premise of ensuring the seepage stability of cushion.

Aiming at the problems of high economic cost and difficult construction of the anti-seepage scheme designed for the dam site area of the concrete face dam of the lower reservoir of a pumped storage power station, a three-dimensional finite element model was established according to the actual engineering situation of the lower reservoir site. Firstly, the distribution of seepage field and the factors such as seepage gradient and seepage flow in each part of the reservoir area under the design anti-seepage scheme were calculated. Then the effects of different curtain depth and the change of curtain length of left and right dam abutment on seepage gradient and seepage flow were analyzed. Finally, the optimization suggestions for the design anti-seepage scheme were put forward. The results show that the curtain depth of the dam site area can be shortened to 3 Lu line, and the curtain length of the dam abutment on the left and right banks can be shortened by about 10 m. Therefore, the project cost can be reduced and the construction progress can be accelerated on the basis that the key parts of the dam site area can meet the seepage stability and the total seepage flow can be effectively controlled.

Aiming at the problem that many measured thermometer data are not effectively used in the previous prediction of crack opening and closing time series data, and there are multiple correlations between their variables, considering the advantages of principal component analysis (PCA) in dealing with multidimensional data and gate recurrent unit (GRU) neural network in dealing with complex time series data, this paper constructed the PCA-PSO-GRU combined prediction model. Taking the monitoring data of the opening and closing of the left inducing joint of a concrete gravity arch dam as a sample, the principal components of the input variables were extracted to reduce the dimension of the input data. And then the model training and multi-step prediction were carried out. The mean absolute error and root mean square error were used to evaluate the prediction accuracy of the model. The prediction results were compared with PSOGRU, PCA-PSO-BP and the traditional statistical regression models. The results show that the PCA-PSO-GRU combined prediction model has higher accuracy in the prediction of inducing joint time series data, which can provide guidance for the evaluation of opening and closing degree of dam inducing joints.

Aiming at the low natural moisture content of natural wide graded gravel anti-seepage soil material in 300 m level high core wall rockfill dam, field contrast test between the process of “belt conveyor filling water + stacker heap + bin stuffy material” and the process of “layered paving + pipe network water + bin stuffy material” was carried out to verify the rationality and feasibility of the relevant filling water process. The test results show that the combination process of belt conveyor with water is superior to the pipe network stratified water process, mainly manifested that the belt conveyor automatic water system can achieve real-time, efficient and accurate automatic water filling soil; After water replenishment, the soil material is transported by the belt and piled by the stacker, which can realize automatic and uniform piling. After adding water to soil material, the moisture content inside the soil material is basically stable during 3-4 days of smother, and the time required for smother is short. This paper also put forward the improvement measures of water filling process of belt conveyor. The improved process of "water filling of belt conveyor + stoker + silo boring" can provide reference for soil water content adjustment of similar earth-rock dam.