The aim of this paper is to describe the drought events in the Zhanghe upstream comprehensively. Firstly, monthly precipitation data were selected to calculate standardized precipitation index. And then, both drought duration and drought severity were identified according to runoff theory. Finally, Copula function was adopted to establish joint distribution between drought duration and drought severity to explore the spatial and temporal distribution of drought characteristics. The results show that the highest frequent drought events in the Zhanghe upstream from 2001 to 2020 is 3 months drought, and the drought severity ranges from 2.24 to 4.92; There is a strong positive correlation between drought duration and drought severity, and Frank Copula function is the most optimal joint distribution function of them; The joint return period of drought characteristics ranges from 18.56-23.94 years, and the northwest and southeast parts of the Zhanghe upstream basin are the two key drought risk areas; The co-occurrence return period of drought characteristics ranges from 22.25-31.94 years, and the northwest, northeast and southeast parts of the Zhanghe upstream basin are the three key drought risk areas. Consequently, it can be obtained that the joint distribution can analyze drought events comprehensively, and thus provide scientific guidance for thorough evaluation of drought.

Danjiangkou Dam is a control project for the development and protection of the Hanjiang River basin, and is also a water source project for the Middle Route Project of the South-to-North Water Transfer Project. The dam operation safety is the support and guarantee of the national strategy. After the dam heightening, the operating water head will increase, and there may be cavitation, and the downstream scour pit will move upward during the flood discharge process. In order to master the mechanical characteristics of flood discharge after heightening the dam and evaluate the safety of flood discharge structures, the parameters such as bottom flow velocity, dynamic water pressure, flow cavitation noise, and scouring under the dam are mainly observed by means of field hydraulic prototype observation, and the results of previous studies are analyzed. The observation parameters under the design water level are within the safe range. Aiming at the problem that the water tongue of the surface hole impacts the middle wall, the opening order of the flood discharge orifice is optimized. The causes of the scour holes in the flow channel and side wall after the flood season are analyzed and the treatment suggestions are put forward. The problems found and treatment measures can provide reference for similar projects.

The risk of water flow compensation caused by the additional discharge of leading hydropower station has increased the difficulty of multi entity cascade hydropower optimal operation, and the backwater jacking effect of downstream hydropower stations has further increased the complexity of the model. Therefore, non-linear modeling is carried out for the flow compensation process of leading hydropower station, and the risk of flow compensation in the compensation period and the recharge period is quantified. At the same time, the impact of backwater jacking effect of downstream hydropower stations on the tail water level of leading hydropower station is considered, and then a scheduling model with the goal of maximizing the joint operation revenue of cascade hydropower stations is constructed. The analysis of the example shows that the method can more reasonably distribute the benefits between the upstream and downstream hydropower stations in the cascade basin, coordinate the conflicts of interests among the multi entity cascade hydropower stations, and improve the activity of the hydropower stations at all levels in participating in the market scheduling.

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 respect to the network security situation and attacks of new types, the needs of trusted computing of applications in SCADA for pumped storage power station was analyzed. Based on the trusted hardware platform and operating system, a system structure of trusted applications in SCADA was proposed, and the key techniques such as trusted distributed services and trusted behavior analysis were discussed. The results show that the proposed design realizes the trusted applications in SCADA, and provides active defense mechanism for SCADA, and adapts to the development of prospective SCADA applications for pumped storage power station.

Based on the agricultural drought-affected rate of 13 major grain producing provinces in China from 1980 to 2019 and the daily rainfall data, the climate-caucusing loss intensity (CCLI) were extracted using H-P filtering, and its responses to dry-days indices (DDI) and large-scale atmospheric-ocean indices (LAOI) were explored. The correlation analysis between CCLI of each province and DDI in different months indicated that summer drought had the higher contribution to the disaster situation, especially the total number of dry days in July was identified as the primary drought-causing factors (PDCF) in 10 provinces. The PDCF in Henan, Jiangsu, Hubei, Inner Mongolia, Jilin, and Liaoning all showed a significant strengthening trends, indicating the intensification of drought risk in the key month of summer; The fluctuation of PDCF in each province had a main cycle of 2-3 years; At the time-lag of 0-12 months, circulation signals such as North Atlantic Oscillation, Pacific Warm Pool, and Arctic Oscillation had the significant impacts on the drought situation. This study can provide scientific basis for regional drought monitoring and early warning.

The total leakage amount behind a certain reservoir dam reaches 16.7 L/s, with the seepage points being the drainage body at the dam foot and the low culvert, but the anti-seepage body inside the dam is weak to slightly permeable and tightly cemented. The image recognition results reveal that the dam body outside the low culvert pipe has formed a penetrating leakage channel. This article selects the centerline of the dam body and the cross-section of the culvert pipe position as example. Based on measured data such as the physical parameters of the rock and soil of the dam body and the leakage amount behind the dam, AutoBank modeling was used to calculate and modify the stability of the dam, while simulating the stability of the reinforced dam. The results show that the water inside the low culvert pipe comes from the water seepage outside the pipe wall, and the leakage points are generally concentrated in the pile number K0+058~0+131.5, mainly in the form of rain or jet, while other sections are in the form of drip or no seepage. The dam body within 2.9 m outside the culvert pipe has formed a penetrating leakage channel, which is the main cause of drainage and culvert pipe leakage. The central section of the dam is in a state of seepage and anti-sliding stability under the conditions of 176.50 m water level, normal water storage level, and check flood level. The cross-section of the dam culvert pipe location undergoes seepage failure under various working conditions, and the calculated total leakage is in good agreement with the on-site measured value; Except for the anti-sliding instability of the upstream dam slope under the condition of sudden water level drop, the dam slopes under all other conditions are stable. After reinforcement, the dam is in seepage and anti-sliding stability under all working conditions.

In recent years, it is urgent to solve the interest allotment problem of multi-energy joint delivery alliance considering the impact of carbon peaking and carbon neutrality goals. Based on the traditional Shapley value method and considering the fairness of contribution, four indicators of resource input, risk allocation, carbon policy impact, and contribution degree were introduced to build an improved MCGC-Shapley based the cloud center method. Taking Sichuan Province as an example, benefit distribution was calculated by quantifying the comprehensive contribution of each party. Compared with the traditional Shapley value allocation strategy, the example analysis shows that the improved MCGC-Shapley benefit allocation method can better achieve the matching between the interests of the main body and the comprehensive contribution, improve the investment enthusiasm, and play a positive role to promote all-win of power generation enterprises and power grid enterprises.

The load rejection process is one of the most dangerous transients in pumped storage hydropower plants. The current design criteria of plant guarantee that the lowest pressure in draft-tube inlet is higher than the saturation pressure during transients, but there is still local cavitation inside the pump-turbines. The one-dimensional pipeline and three-dimensional pump-turbine coupled computational fluid dynamics simulation method was used to simulate the simultaneous load rejection process in a pumped-storage hydropower plant. The results show that a spiral cavitation cavity is in the center of the draft-tube inlet, and five wedge-shaped cavitation cavities are in the outlets of runner channels. The collapse of the spiral cavitation cavity in the draft-tube leads to instantaneous pulse impacts on the pressure and runner forces. There is no obvious impact when the wedge cavities collapse.

Fenghuangjing new station belongs to the front inflow pump station with large diffusion angle. Large scale off-wall reflux is easy to occur at the bank walls on both sides of the forebay, which can not provide good inlet conditions and endanger the safe and stable operation of the pump station. Forebay at river diversion side of Fenghuangjing new station was taken as the research object. Based on the CFD numerical simulation software, the improvement effect of trapezoidal sill position and height on the flow pattern in the forebay of the front inflow pump station with large diffusion angle was studied. And the numerical simulation results were verified by physical model tests. The results show that when the trapezoidal sill is located at 10 m from the entrance of the forebay and the height of the sill is 1.2 m, the inflow conditions of Fenghuangjing new station can be better improved. The research results can provide technical support and reference for this project and the similar projects.