Under the background of global climate change, river flood risk assessment is of great significance to disaster prevention and mitigation in river basins. By analyzing the spatiotemporal change characteristics of floods in the Nanliu River Basin from 1960 to 2021, a flood risk assessment index system was established for flood risk assessment. The results show that the interannual variation of flood disaster in Nanliu River shows a fluctuating upward trend; 1993 was a big catastrophe year of flood disaster change; On the whole, the upstream basin, the middle river valley and the downstream estuary plain are the flood prone areas, and the flood risk shows a distribution pattern of high in the southeast and low in the northwest, which is consistent with the characteristics of historical flood data. The results can provide scientific basis for the comprehensive management of Nanliu River Basin.

The effect of luring fish is one of the key factors affecting fish passing efficiency in the entrance area of fish-passing facilities. Proposed a new optimization idea of side-channel drop-flow to lure fish. The upstream water was replenished to the area outside the fishway entrance as drop-flow. With the help of auxiliary facilities such as cantilever plate, the attractive flow was formed in the horizontal orientation. Take the fishway project of Shaping I Hydropower Station as example, a large scale physical model was established to demonstrate and optimize the scheme, and the flow pattern near the entrance of the fish-passing facility were analyzed, and the possibility of attracting fish was discussed. The experimental results show that the one-dop scheme is favorable for attracting the migratory fish in the horizontal orientation, with the flow velocity of 0.3-0.5 m/s, and the information of flow pattern is rich in the entrance area, which is suitable for fish aggregation.

Aiming at the problem of urban waterlogging caused by heavy rainstorms in coastal cities, this paper takes Fuzhou City as an example and constructs a fined coupling model of urban one-dimensional drainage network and two-dimensional land surface hydrodynamics based on Infoworks ICM. The model was applied to the analysis of rainstorm waterlogging in Gutian Road area of Fuzhou during Typhoon "Lubi" in August 2021, which verified the high simulation accuracy of the model. Based on this model, the rainstorm waterlogging process in Gutian area under different recurrence periods was analyzed, and two "sponge" reconstruction schemes were proposed. It is found that increasing the pipe diameter is more conducive to improving the waterlogging situation in the study area. The study can be used to accurately calculate the process of urban underground drainage and land area water in Fuzhou City, which provide technical support for the real-time decision of flood control and drainage in coastal cities.

Baishuihe landslide is a typical representative of bedding landslide in the Three Gorges reservoir area. However, the research on its formation evolution process and deformation characteristics after water storage is not deep. On the basis of field geological investigation and the latest survey data and GPS monitoring data, this paper makes a detailed study on the rock and soil structure of Baishuihe landslide and its deformation characteristics after impounding. The results show that the evolution process of Baishuihe landslide has gone through the early stage of landslide, the rock landslide and the accumulation landslide. At present, Baishuihe landslide is in the accumulation landslide stage; Baishuihe accumulation landslide is the product of vertical superposition of landslide accumulation bodies caused by the destruction of the second-stage rock landslide, and there is a clay layer in the middle. Corresponding to the water level of 135 m and 156-175 m, the deformation of Baishuihe landslide can be divided into two stages. The deformation characteristics of Baishuihe landslide are gently inclined steps and steeply inclined steps. The research results provide the corresponding decision-making suggestions for the treatment of Baishui River landslide, and also provide the direction for the later treatment of geological disasters with similar structural characteristics.

With the development of urbanization in China, secondary water supply has become a key part of urban water supply, but the utilization efficiency of water resources is low. This paper proposes the Demand Side Management (DSM) model based on the user's perspective. Starting from the user's Demand Side Management, the low water tank in the secondary water supply system at the end of the pipe network is taken as the research object. Using adaptive FCM clustering analysis and grey relational analysis, the paper analyzes the characteristics of user water use in different types of small areas, excavates the potential of regulation and storage and studies the peak-shifting scheme, and determines the appropriate peak-shifting scheme, so as to achieve good peak-shifting by demand-side management.

Aiming at the nonlinear problem of regret value when regret theory is used to solve multi-attribute group decision making problems in hydraulic engineering, a multi-attribute group decision making method combined with grey correlation analysis method is proposed. Firstly, the regret theory was used to obtain the decision maker's perceived utility for each option and determine the regret decision matrix. Secondly, according to the nonlinear problem between regret values, the weight of attributes and the comprehensive regret value of each scheme were calculated by grey correlation analysis, and then the best scheme was obtained according to the ranking of the comprehensive regret value. Finally, the feasibility of the method was verified by case analysis. The results show that this method can solve the nonlinear characteristics and weight problems in regret theory, and make decision-making more reasonable when considering psychological factors.

The emergency shutdown device of the hydro-generator governor should not only meet the requirements of "power loss action" in the 25 anti-accident measures, but also avoid the hidden danger of unplanned outage of the unit caused by the electromagnetic valve coil of the device being charged for a long time and easy to burn. This paper introduces three generations of technical improvement of the emergency shutdown device of hydro-generator governor of a large hydropower station, from double electromagnet two-position solenoid valve, single electromagnet spring return two-position solenoid valve to double solenoid valve and linkage valve, expounds their working principle and compares their respective advantages and disadvantages. It is proved that the emergency stop device of hydro-generator governor based on double solenoid valve and linkage valve is a practical and reliable emergency stop control optimization scheme of speed regulating system, which has great popularization value in hydropower plants.

The Xiongan storage reservoir is a pumped storage reservoir, an important water source project supporting the construction and development of the Xiongan new area, and a key supporting project to ensure the safety of water supply in the new area, with high requirements for project seepage prevention. The F₁₇₃ fault, which is the largest fault in the reservoir basin, runs through the NE-SW direction, and forms low passes on the NE side and the SW side of the reservoir basin, and there is local dissolution along the fault. The lithology and structural sealing conditions of the reservoir are poor. In order to control the seepage of the reservoir, curtain grouting was used to prevent seepage around the reservoir. In order to explore a suitable implementation method for curtain grouting of Xiongan storage reservoir, it is necessary to determine the anti-seepage treatment measures, grouting construction method and construction technology of the F₁₇₃ fault through grouting test research. The results indicate that the permeability meets the anti-seepage standards and the fatigue resistance is improved.

In view of the problem that the comprehensive output coefficient of power station deviates from the actual situation in varying degrees with the accumulation of operation time, the change of operating conditions, unit wear, the comprehensive output coefficient was calibrated according to the average comprehensive output coefficient and the piecewise fitting coefficient. The piecewise fitting method was further divided into piecewise fitting according to the water head and piecewise fitting considering the water head and power generation flow in terms of the dispatching characteristics. The results were verified by precision evaluation. Combined with the historical operation process of Hongjiadu Hydropower Station, a case study was carried out. The results show that compared with the actual results, the relative error of the average coefficient method is 2.64%, that of the piecewise fitting method according to the head is 2.52%, and that of the piecewise fitting method considering the head and flow is 0.59%. The piecewise fitting method is closer to the actual production process than the average comprehensive output coefficient method, and the piecewise fitting method considering the head and power flow is the most accurate.

Setting a panel outside the soilbags-constructed retaining wall may affect the behavior of the wall. Therefore, a full-scale test of the soilbags-constructed retaining wall with fixed panels and with unfixed panels were conducted to explore the influence of the panel on the deformation mode and lateral earth pressure of the wall. The results show the walls with fixed and unfixed panels deformed laterally in a cantilever-like manner, but the lateral earth pressure acting in the fixed-panel wall is greater than that in the unfixed-panel wall. A calculation formula for calculating the earth pressure acting on the soilbags-constructed retaining wall under limited displacement was established based on the linear elastic constitution theory, and then it was used to analyze the relationship between the lateral earth pressures and lateral strain. It is found that distribution of the lateral earth pressure of the soilbags-constructed retaining wall with unfixed panel is close to the calculated active earth pressure as a result of the poor deformation constraint of the unfixed-panel, which indicates that the flexible characteristics of the soilbags-constructed retaining wall can be fully utilized by the wall with unfixed panel, so as to effectively reduce the earth pressure behind the wall.