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.

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 problem of low economic benefits of pump stations caused by unreasonable dispatching, this paper took the pump stations with multiple piping systems as the research object. Considering the impact of peak-valley electricity price, a pump station daily economic optimization model was established by taking the minimum daily operating cost as the goal. The secondary pump station of the connected river reservoir project was taken as a study case to compare constant speed throttling regulation and frequency conversion regulation, which bases on the improved genetic algorithm and dynamic programming method of combined variation. The results show that the improved genetic algorithm is suitable for optimal dispatching of pumping station. At the same time, it is found that when the actual operating points of the pump unit far from the design operating point, adopting frequency conversion regulation has higher economic benefit.

In view of the difference between the performance of cemented gravel soil under low normal stress and high normal stress, based on the Mohr-Coulomb strength criterion, according to the Mohr-Coulomb strength line of cemented gravel soil before and after yield stress, a polygonal line strength criterion of cemented gravel soil was proposed. The relationship between strength criterion parameters and uniaxial compressive strength and uniaxial tensile strength was deduced. Uniaxial compression test and direct tensile test were carried out to calculate the strength criterion parameters and compare with the strength criterion parameters obtained by triaxial compression test. The results show that the error range between the calculated value and the experimental value is reasonable. The polygonal line strength criterion is suitable for cemented gravel soil.

Anti-dip layered rock slope is a common type of slope in hydropower engineering. Its stability is controlled by slope geometry, rock characteristics and structural plane properties. To reveal the influence of multiple factors on the stability of such slopes, taking the safety factor and displacement as dependent variables, the significance of six main factors, namely slope angle, slope height, rock inclination angle, rock thickness, rock quality and structural plane quality, was studied based on the approaches of discrete element modelling and orthogonal test design. Moreover, the deformation and failure laws of typical modes for anti-dip slopes were analyzed. The study can provide a reference for the optimal design of anti-dip layered rock slopes.

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.

When the pipeline truck moves smoothly, the velocity distribution characteristics of the water flow in the annular gap are related to the interaction between the pipeline truck and the water flow, which will also affect the motion characteristics of the pipeline truck and the hydraulic characteristics in the pipeline. This paper studied the overall and local distribution characteristics of the water flow velocity in the annular gap when the pipeline car moves smoothly by means of physical experiments and theoretical analysis. The relationship between the distribution characteristics of the water flow velocity in the annular gap of the pipeline car with different diameters and the transmission efficiency were compared. The results show that when the pipeline car moves smoothly, the velocity at the inlet section of the annulus is the largest, followed by the middle section of the car, and the velocity at the rear section of the car is the smallest; The flow velocity near the wall of the pipeline truck changes greatly along the way, and the flow velocity near the pipe wall changes less along the process; The distribution of the water flow velocity in the annular gap of the pipeline car with different diameters affects the transportation efficiency of the pipeline car. When the ratio of the water flow velocity in the annular gap to the water flow velocity in the pipeline is close to 1, the transportation efficiency of the pipeline car is the highest.

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.

Drought prediction is an important non-engineering measure to improve drought prevention and resistance. This paper firstly evaluated the ability of multi-scalar standardized precipitation evapotranspiration index (S_SPEI) to identify drought events in Henan Province. Then a drought prediction model based on particle swarm algorithm optimized extreme learning machine (PSO-ELM) was constructed, which used S_SPEI as model outputs and major drought-causing climate system indices selected by Information Changing Rate and Conditional Mutual Information-Based Input Feature Selection Method (ICR-CMIFS) as model inputs. The applicability of the PSO-ELM model in drought prediction in Henan Province was verified by comparing the drought prediction results of this model with standard extreme learning machine (ELM) and differential evolutionary algorithm optimized extreme learning machine (DE-ELM) models. The results show that the S_SPEI-3 can effectively identify specific drought events in Henan Province and reflect the drought situation in Henan Province accurately in terms of time and space; The main drought-causing climate system indices in Henan Province screened by ICR-CMIFS are the western Pacific paratlantic area index and the NINO index; The PSO-ELM model can predict drought in Henan Province accurately, and the prediction accuracy is better than that of the DE-ELM model and standard ELM model, which has better applicability in drought prediction of Henan Province.

This paper selected 6 typical cape-bay sandy beaches in Wenzhou area to sort out the natural environment. The parabolic plane morphology model (MEPBAY) was used to compare the relative positions of the static simulated shoreline with the recent actual shoreline. The advancing and retreating trend of the coastline of the shaped sandy coast was analyzed. The current stability of the coastal beaches of Cape Bay in Wenzhou area was discussed. The results show that the coastline is in a stable state as a whole, and the profile of sandy beaches is mainly divided into four types: concave downward, upward convex, slope, and slope + upward convex combination. The characteristics of the interannual erosion and deposition changes of the profile are mainly divided into three modes: the upward erosion and the downward siltation, the overall erosion type and the basic stable type.