In order to alleviate the water shortage in the development of oil and gas resources, horizontal wells are often used to exploit groundwater resources, but there is little analysis on the factors affecting the water intake of horizontal wells. Therefore, the numerical model is used to simulate the horizontal well mining mode and explore the influence of horizontal well layout direction, burial depth, pipe length and well pipe permeability on the water intake effect. The results show that considering the water intake efficiency and construction difficulty, the optimal horizontal well layout direction should be laid along the incoming water direction, and the location should be located in the upper layer of Luohe Formation as far as possible. The recommended pipe length and well pipe permeability are 800 m-1 000 m and 0.15, respectively, and the corresponding production volume is 1 368 m³/d-2 389 m³/d. The research results have important guiding significance for alleviating the shortage of water resources in the development of oil and gas resources in the eastern region of Longdong and formulating reasonable development strategies of water resources.

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.

The Guangxi coastal of Beibu Gulf has abundant water resources, but the inter-annual distribution is uneven under the influence of El Niño/La Niña events. The Nanliu River is the largest river located in the costal of Beibu Gulf, Guangxi. Based on SWAT model, the characteristics of blue water, green water flow, and green water storage in typical El Niño/La Niña years in the river basin were quantitatively analyzed. The results show that from 1971 to 2015, the annual average blue water, green water flow, and green water storage in the river basin was 835.0 mm/year, 929.0 mm/year, and 114.0 mm/year, respectively. In the typical El Niño years (1997)/La Niña years (2007), the blue water, green water flow and green water storage in the river basin are 145.7%/51.6%, 92.4%/96.9% and 115.5%/78.3% of the multi-year average, respectively. The El Niño/La Niña event caused a significant increase/decrease in precipitation in the river basin, which mainly affected the amount of blue water. Due to humid climate in the basin, the amount of green water flow was mainly affected by solar radiation and wind speed. The research can provide an important reference for the rational and efficient utilization of water resources and the high-quality development of the region.

Aiming at the two failure modes of hydraulic steel gates, the relative deformation failure under the normal service state and the bending shear composite strength failure under the limit state of bearing capacity, the corresponding failure probability analysis models were established respectively. The influence of different parameter distribution types on the failure probability of two failure modes of outcrop steel gates and deep-hole steel gates in hydraulic steel gates was explored through Monte Carlo simulations. The results show that under the same failure mode, when the coefficient of variation of the variable itself remains unchanged, the failure probabilities obtained by different distribution types are relatively close. Compared with the outcrop gate, the deep-hole gate has a higher failure probability and is more prone to instability. But the type of parameter distribution has little influence on the failure probability of deep-hole gate and has great influence on the outcrop gate. When the random variables of each parameter follow the logarithmic normal distribution, it will have a relatively maximum failure probability. It is easy to overestimate the reliability of hydraulic steel gates by considering only the normal distribution.

After a blackout occurs resulting from an extreme disaster, the active distribution network with distributed generation and energy storage equipment can perform service restoration by island partition and network reconfiguration. To solve the service restoration problem for the active distribution network with uncertain wind power output, this paper proposes a two-stage service restoration model based on robust stochastic optimization. In the first stage, the event-wise ambiguity set of wind power output is constructed based on the historical data and the model which minimizes the outage cost is solved by the robust stochastic optimization method. In the second stage, the energy storage and controllable loads in the distribution network are used to track the wind power output, so as to optimize the scheduling during the fault recovery of the distribution network, which minimizes the outage cost and the total power loss. Finally, the superiority of the proposed the model and strategy is verified by the simulations of a modified IEEE 33-bus distribution system case.

Water and sediment conditions are complicated in waters affected by the interaction of flood and tide. Therefore, the bend regulation in these waters is more difficult and its effect is more uncertain than that of ordinary rivers. This paper aims at the above problems by taking the treatment project of Wenjiayan bend as an example, which lies in Qiantang estuary. This treatment project consisted of the riprap protection at concave bank and retreating dike at the opposite bank combine with the shoal-cutting measure. Based on the observed hydrology and topography data for years, the variation of flow conditions, deep channel distribution, scouring elevation and siltation velocity before and after the project was analyzed. The results show that the bend effect is greatly weakened and flow conditions are improved after the treatment. Meanwhile, the deep channel in the bend reach moves from the foot of the dike to middle. These results can provide reference for measures to similar sharp-bend treatment. Meanwhile, the balance section area after the project implementation was predicted through the methods of river correlation coefficient method and section average statistics. The dredging conditions of the reach were determined, which can provide guidance to operation and maintenance for the subsequent project.

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.

The unsteady inflow process changes the hydrodynamic characteristics of the compound open channel and then determines the processes of material transfer and energy transfer in the floodplain and main channel. In order to study the influence of different unsteady inflow processes on the hydrodynamic characteristics of the compound open channel, indoor flume experiments were carried out to analyze the influence of different unsteady inflow processes on the water level, flow instability, and discharge per unit width process of the compound open channel, taking into account three factors: discharge amplitude, unsteady period, and rising duration. The results show that with the increase of discharge amplitude, the slope of wave peak growth of water level is greater than that of wave valley, and the wave height increases linearly. The discharge process of the unit width of the channel is deformed over time, and there is an obvious slow change process in the descending process of the main channel and the rising process of the floodplain. With the increase of the unsteady period, the wave peak of the water level increases, the wave valley decreases, and the wave height also increases linearly. The phenomenon of deformation of the unit width discharge of the channel over time disappears. The water level peaks and valleys change synchronously with the hydrologic skewness. When the hydrologic skewness (ratio of fluctuation water duration) is greater than 1, the rising process of the unit width discharge of the floodplain and main channel will also have an obvious slow change stage.

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.