Taking 16 cities and prefectures in Hubei Province as the research object, from the perspective of unexpected output, DEA-SBM model was used to calculate the water environment governance efficiency from 2014 to 2018. Combined with GIS spatial analysis method, the temporal and spatial variation characteristics of urban water environment governance efficiency were explored, and the influencing factors of urban water environment governance efficiency were analyzed by multiple linear regression model. The results show that the efficiency of urban water environmental governance in Hubei Province has rising trend, but there is a difference in time-order changes in water environmental governance between different cities; The efficiency of urban water environment treatment in Hubei Province shows a spatial distribution trend of low in the central region and high in the eastern and western regions; The level of infrastructure and environmental regulation have a significant positive impact on urban water environmental governance, and urbanization level has a significant negative impact on water environmental governance efficiency.

The internal defects of rock mass have a significant effect on its mechanical properties and damage and fracture. The influence of fissure angles and bridge lengths on rock mechanical properties and failure was analyzed by uniaxial compression test and DIC technique. The research findings are as follows: The peak stress and elastic modulus of the samples have an obvious change trend with the change of the fissure angle. Compared with the length of the rock bridge, the fissure angle has a more significant effect on the mechanical properties of the rock. With the increase of fissure angle, the number of surface cracks, main failure cracks and surface spalling decreases, while the area of falling blocks increases obviously. However, with the increase of bridge length, the characteristics of crack propagation and spalling are basically the same. In the process of crack propagation, the connection of rock bridge is related to the fissure angle and the length of rock bridge. In the low fissure angle, the failure mode of rock samples is dominated by tensile failure cracks; With the increase of the fissure angle, the performance is as follows: the tension damage crack to shear damage crack transformation to form a mixed tensile shear damage mode; At the same time, with the increase of bridge length, the more difficult the rock bridge is to penetrate, and the local crack expansion failure changes from tensile-shear crack to tensile crack.

The phenomenon of oil spilling and oil spilling in the lubricating oil system of the water guide bearing occurs frequently during the operation of the pumped-storage unit, which significantly affects the safety and stability of the unit and the operating environment of the power station. With the help of CFD numerical simulation technology and VOF multiphase flow simulation method, the dynamic characteristics of water guide bearing lubricating oil system in the multi-oil level working condition under the pumping mode of the pumped-storage unit were explored. The research results show that under the low oil level condition, the system flow cycle is formed faster, the flow state is stable and the oil level is low during the transition process, so the oil rejection phenomenon is milder, but too low oil level may lead to unfavorable control of oil temperature; Under the condition of high oil level, the phenomenon of oil spillage in the early stage of the flow mostly occurs near the side of the Pitot tube of the rotating oil basin, and it mostly occurs on the other side of the Pitot tube in the later stage of the flow. Compared with the traditional method of increasing the diameter of the Pitot tube, the method of optimizing the outer wall of the Pitot tube is more effective in suppressing the phenomenon of oil spillage. The results provide a theoretical basis for exploring the causes of the oil spill phenomenon in the water guide bearing lubricating oil system of the pumped-storage unit and the optimization of the oil slinger.

The space angles of inclined supporting arm of large radial gate are easily confused and mistaken, and its small errors may cause large structural errors, which will affect the manufacturing, installation and safe operation of the radial gate. Therefore, this paper defined, distinguished and calculated several key space angles of the radial gate inclined supporting arm. Taking an actual project radial gate as an example, the influence extent of each key angle of the inclined supporting arm on the manufacturing and installation accuracy of the gate was analyzed. Furthermore, this paper put forward several measures to improve the manufacturing and installation accuracy, which can be used as a reference for the subsequent design, manufacturing and installation of radial gate with inclined supporting arm.

In order to analyze the influencing factors and their correlations of water use efficiency, incorporate all independent variables and overcome multicollinearity, the partial least squares method was used to study the correlation factors of water use efficiency in 2019 in China. The results show that the partial least square method can describe the correlation between variables effectively. Factors that are highly correlated with water consumption per ten thousand Yuan of GDP are natural conditions, social development level, GDP proportion of added value of primary industry, and the proportion of labor force in the water industry. The overall economic water use efficiency is high in the eastern region and low in the western region. Factors that are highly correlated with actual irrigation water consumption per mu of cultivated land are natural conditions and GDP proportion of added value of primary and secondary industries. Agricultural water use efficiency is high in the central region and low in the western region. Factors highly correlated with the water consumption per ten thousand Yuan of industrial added value are natural conditions, sewage treatment rate, urbanization rate and the capital proportion of water industry. Industrial water efficiency is high in the eastern region and low in the central region. Factors highly correlated with per capita public water consumption are per capita water resources, annual precipitation, sewage treatment rate, per capita GDP and GDP proportion of added value of primary and secondary industries. There is little correlation between regional factors and public water use efficiency. The research results can provide reference for the optimal management and rational utilization of water resources.

In order to analyze the dynamic response law of geotechnical slope, support and cavity structure under strong earthquake, taking a cavity section project in northwest China as an example, this paper firstly proposed a comprehensive management plan and then analyzed the management effect by combining field monitoring and FLAC^3D numerical simulation. Finally, the effect of support structure and cavern chamber on the dynamic response of rocky soil slope was analyzed under strong seismic load, and some suggestions for seismic protection of cavern section were discussed. The results show that after the treatment, the stability coefficient increases from 1.140 to 1.473, an increase of 29.2%; The imposition of the support structure effectively reduces the acceleration and displacement of the slope and cave roof axis; The presence of the cave chamber has a greater impact on the cave axis compared with the impact of the slope dynamic amplification effect; By analyzing the acceleration of the slope and the tunnel axis vault lining, the maddle is very important for the slope seismic resistance. It is suggested that the seismic protection length of the project should take the range of 3.4 and 4.8 times the diameter of the cave.

The local open channels play a certain role in regulating and storing water, but the water flow in the junction section with open channel variation and pressure is relatively complex, which may cause adverse water flow phenomena such as air intake, whirlpool and surges. In order to study the hydraulic pattern of the connecting section between the open channel and the pressurized tunnel, based on the water conveyance tunnel of Wenzhou Oujiang water diversion project, a 30:1 large scale normal local hydraulic model was built according to the gravity similarity criterion. The hydraulic pattern, water surface line distribution, velocity distribution and wave characteristics under different conditions were observed through hydraulic model tests. The flow trend, depth, velocity and wave characteristic parameters under different working conditions were obtained. The research results show that the flow in the open channel and the pressurized junction section through the gradual transition is in good shape, and there is no air intake, backflow and surge, which provides support for the safe operation of the project.

Aiming at the problem that the evaluation and prediction of water resources carrying capacity involves multi-factor comprehensive indicators, particle swarm optimization algorithm was used to optimize the training parameter penalty factor C and kernel parameter σ in the support vector machine model, and a water resources carrying capacity prediction model was established based on PSO-SVM. According to the index grade standard, the training set data was constructed to evaluate the water resources carrying capacity of Heilongjiang Province in 2017. The results show that the water resources carrying capacity index of Heilongjiang Province in 2017 is between 0.423 4 and 0.709 2. The water resources carrying capacity in some areas is at level II, the carrying capacity is weak, and there is still much room for improvement.

Naolihe National Nature Reserve is located in the hinterland of Heilongjiang Sanjiang Plain and is an important ecological function area in China. Based on remote sensing image data and hydrological data of the protected area, this paper inversed the vegetation coverage by pixel dichotomy, analyzed the spatial and temporal distribution characteristics of vegetation coverage in Naolihe Nature Reserve from 1984 to 2021, and studied the influence of precipitation and flooding frequency on vegetation coverage. Studies have shown that from 1984 to 2021, the low and middle vegetation coverage areas of Naolihe wetland first increased and then decreased, while the middle and high vegetation coverage areas showed the opposite trend. From the correlation coefficient between annual monthly precipitation and monthly vegetation coverage, the vegetation growth in Naolihe Nature Reserve is greatly affected by precipitation, which is positively correlated, and the response of vegetation coverage to precipitation is about one month behind. When the frequency of wetland flooding is between 0.45 and 0.50, the wetland vegetation grows well. The research can provide reference for Nalihe wetland ecological protection.

To analyze the impact of unsteady state friction and tube wall viscoelastic on leakage, based on the energy conservation theory of the transient flow in a closed pipeline, the leakage numerical model for the hydraulic transient pipeline was constructed considering the dynamic term in the unstable friction and the elastic viscosity effect of the pipe wall. The transient flow reverse analysis method (ITA) was improved. As a case study, Xujiaya Reservoir Irrigation District in Shandong Province was selected to carry out field experiments. The leakage process was assumed to be quasi-normal distribution. Based on the field water flow transient test data, pipeline leakage location and leakage amount were simulated. The simulated error was calculated by the ITA method. When a single point leakage occurs in the experimental pipeline, the average location error of the simulated leakage is 1.44%, and the maximum error is 6.89%, the average area error of the simulated leakage hole is 3.85%, and the maximum error is 14.77%. When multipoint leakage occurs in the experimental pipeline, the average error of the simulated leakage location is 1.31% and the maximum error is 3.91%; the average area error of the simulated leakage hole is 1.74% and the maximum error is 4.35%. The study results could provide theoretical and technical support for the leakage detection of water pipelines.