The contradiction between the supply and demand of water resources becomes increasingly acute, so it is particularly important to optimize the allocation and efficiently utilize the limited water resources in the region. Water resources allocation in Hengshui city was taken as a case study. The demand of optimal allocation of Hengshui city water resources was considered comprehensively. The multi-objective optimal allocation of water resources model was established by taking the social benefit, economic benefit and ecological benefit as the objective function. The scheme of optimal allocation of water resources based on MOEA/D algorithm was given, and comparison experiments between the proposed scheme and the scheme based on NSGA-Ⅲ algorithm was done. The experimental results show that proposed scheme is superior to the scheme reported by literature, which can provide relevant support for the rational allocation of water resources in Hengshui city.

Taking Dawen River Basin in Shandong Province as an example, Mann-Kendall method was used to analyze the consistency of the 6 h, 12 h, 24 h and 3 d annual extreme rainfall data. The regional linear moment method was used to infer the design value of the site rainstorm, and the regional design value was compared with the single-station linear moment method. The spatial distribution map of the design value of the 50-year rainstorm in Dawen River Basin was drawn. The results show that the Dawen River Basin can be divided into 3 hydrometeorological homogeneous regions, and the optimal distribution frequency linetype is dominated by the generalized extreme-value distribution (GEV). The difference (mean absolute relative error) between the results of single-station L-moment frequency analysis method and regional L-moments frequency analysis method decreases with the increase of the length of the sample series, and the larger the return period is, the greater the gap is; The spatial distribution of the designed rainstorm values in Dawen River Basin is not uniform, but the distribution trend of each period is basically similar.

Vertical seam fishway has gradually attracted the attention of hydraulic engineering field because it can adapt to large amplitude water level, obvious energy dissipation effect and stable flow pattern. In this paper, the influence of the length width ratio of the pond on the hydraulic characteristics of the opposite side vertical slit fishway was studied by numerical simulation. The results show that the change of the length width ratio of the pond has little impact on the dissipation rate per unit volume; The attenuation along the main flow area first increases with the increase of the length width ratio of the pond, and then remains unchanged. The larger the length width ratio of the chamber is, the closer the maximum velocity in the chamber is to the vertical joint; The ratio of the main flow velocity to the maximum flow velocity (the maximum variation of the main flow velocity along the way) is within a certain range. The length width ratio of the pond is between 1.00-1.13, which can obtain better water flow pattern, larger reflux area and better water quality in the mainstream area of the fishway.

In order to study the temporal and spatial evolution characteristics of internal dynamic response and energy transfer of fresh concrete under the action of surface vibration load, a laboratory vibratory plate compaction test of fresh concrete was carried out. Real-time dynamic response characteristic parameters were obtained by acceleration sensors at different buried depths in the compaction process of vibrated concrete. The vibration signal was denoised by wavelet threshold denoising method. The temporal and spatial evolution law of internal motion energy of fresh concrete was analyzed by measuring point acceleration response. The results show that the aggregate particles near the surface vibration source mainly move vertically, and the surface of fresh concrete is obviously settled on the macro scale. With the increase of burial depth, the internal particles at the far end cannot get enough vibration energy, so it is difficult to overcome the extrusion force between particles and the friction resistance in the medium and maintain the initial equilibrium state, which is less affected by vibration. The vertical acceleration of internal particles is greater than the lateral acceleration during the vibration compaction of fresh concrete. With the increase of the compaction degree of fresh concrete, the vertical acceleration amplitude first decreases and then basically remains unchanged, while the lateral acceleration amplitude first decreases and then slightly increases. The vibration energy attenuation of concrete near the vibration source is the largest, but it is not significant with the increase of buried depth. The work in this paper can provide reference for the theoretical construction and in-depth study of vibration compaction of fresh concrete.

In order to reveal the influence of the gate opening on the hydraulic characteristics of hydraulic tunnels, a two-dimensional model of silt-releasing tunnel with different gate openings was established. The VOF method and standard κ-ε turbulence model were used for three-dimensional numerical simulation calculation of flow field in abrasive section of flood silt-releasing tunnel. The hydraulic characteristics such as flow state, velocity and pressure near the gate were obtained. The hydraulic characteristics under different gate opening degrees were analyzed to obtain the cavitation number from the gate to the threshold. The results show that when the gate operation opening is less than 1/2 maximum opening, the larger the gate opening is, the smoother the tunnel flow state is, the smoother the flow velocity near the bottom is, the lower the pressure difference between the upstream and downstream of the tunnel floor is. The smaller the gate opening is, the smaller the flow rate in the pressure cave is, and it is easy to cause sediment deposition; The greater the opening of the gate is, the more favorable the overall operation of the tunnel is. The research results have guiding significance for the optimization of the operating opening of the hydraulic tunnel gate and the anti-wear repair of the gate bottom sill.

The structure of large-scale shaft tubular pumping station is complex, the structure and size of each pouring block are different, and the temperature control index is also different. Especially in summer construction, it is very difficult to control temperature and prevent cracks. For different structural parts, refined peak clipping strength index should be adopted. In this paper, the equivalent cooling algorithm was used to simulate the peak-cutting intensity of cuboid pouring block under different water pipe layout, water temperature and water flow rate with different hydration heat inhibitor dosage and without hydration heat inhibitor. Then a series of quantitative formulas were put forward. According to the dosage of hydration heat inhibitor and peak-cutting intensity index, the layout density and water flow rate of cooling water pipes with corresponding water temperature can be calculated with these formulas. The results can provide quantitative reference for the establishment of temperature control measures for similar pumping stations constructed in high temperature season.

In order to explore the calculation method of water demand of water-reduced river landscape under hydropower development, combined with the data of hydrology and social economy in the region, this paper compared the changes of landscape characteristics after water reduction in similar projects. Taking the water reduction channel caused by Danba Hydropower Station as an example, the landscape evaluation factors were chosen comprehensively. Considering human visual effects, the landscape water demand evaluation system was established. A calculation method for the landscape water demand of the water-reduced reaches caused by the construction of hydropower stations was proposed. Based on the hydraulic model, the landscape indicators of each river section were calculated according to the determined index system, and the water volume required for the wide valley section, canyon section and county river section to meet the landscape requirements of water-reduced river channels is 70.4 m³/s, 64.8 m³/s, 50.7 m³/s. The 70.4 m³/s is taken as the landscape water demand of the whole reach of the reduced water.

In order to comprehensively evaluate the water environment health status of Poyang Lake, a quantitative evaluation index system was established from three aspects of water quality, hydrology and aquatic organisms. The comprehensive weighting method combining analytic hierarchy process and coefficient of variation method was used to determine the comprehensive weights of indicators. The TOPSIS method was applied to construct the evaluation model, which determine the score of evaluation objects by combining the weights of indicators. The results show that there are seasonal changes in the water environment health status of Poyang Lake, and the two indicators of hydrology and aquatic organisms in summer are obviously better than other periods, so that water environment health grade is the highest and belongs to grade Ⅰ, with better coordination; The water environment health grade in autumn and winter is the worst and belongs to grade Ⅲ, among which hydrological condition is the main influencing indicator. This study can provide reference for water environment protection and construction of Poyang Lake.

As a common safety problem in water diversion engineering, water hammer is often caused by abnormal operation of valves, So, it is necessary to conduct a comparative analysis of water hammer problems under different valve adjustment methods. The CFD technology and dynamic mesh technology were used to simulate different single and double valve adjustment modes, and analyze the fluctuation of water hammer pressure at different locations in the pipeline. The results show that when the single valve is adjusted, the first fast and then slow closing valve mode has an inhibitory effect on the water hammer within a certain range of fast shutdown; The fast closing amount is too large, which will play a worsening effect of water hammer; When the fast shutdown amount is 60%, the water hammer pressure can be effectively controlled, and the water hammer will deteriorate when the fast shutdown amount is 80%; When adjusting the double valve, considering the pressure before and between the two valves, it can be found that the “first 0.25 s off 60%, the last 0.25 s off 40%” method can avoid the occurrence of excessive pressure and negative pressure. The research result provides a design and operation scheme for the rapid shut-off process of the valve in practical engineering.

In order to overcome the difficult problem of establishing multi-factor and non-linear complex relationship of reservoir sand discharge and achieve its accurate prediction, four machine learning algorithms including XGBoost, KNN, SVR and RF were used to predict and analyze the sand content of reservoir outflow based on the series data of Wanjiazhai reservoir from 2002 to 2020, respectively. The results show that the use of machine learning algorithms can effectively realize the reservoir discharge prediction considering different influencing factors. The applicability of different machine learning algorithms in reservoir discharge prediction varies. In comparison, the highest coefficient of determination R² of the reservoir discharge prediction model based on RF algorithm is 0.9349, and the corresponding average absolute error and root mean square error are the smallest, which are 2.974 and 4.886, respectively. The prediction effect of the RF algorithm is better than the other three algorithms. The proposed method can provide a theoretical basis for accurate prediction of reservoir sand discharge and optimization of scheduling scheme.