In order to realize the sustainable utilization and maintain the healthy development of river and reservoir ecosystem, this paper applied energy value analysis to reservoir ecological operation for discussing the energy optimal operation of reservoir ecological service value. With the objective of maximizing the service energy of Manwan Reservoir and the constraints of ecological water demand and social economic water consumption, an optimal operation model of reservoir ecosystem service energy was established, and the ant colony algorithm was used to solve the model. The results show that the total service energy of Manwan Reservoir is 2.10×10²² sej in high flow year, 1.79×10²² sej in normal year, 1.58×10²² sej in dry year. Main service values are ecological regulation, water supply and ecological support, material production followed, cultural entertainment is the minimum. The results have practical value and important significance for maintaining the healthy development of the Lancang River basin, especially for the ecosystem of the Manwan Reservoir Region.

In order to alleviate the waste of resources caused by the leakage of urban water supply networks, taking predictive classification as the basic idea, the monitoring data after wavelet noise reduction processing was used in the prediction model of PSO seeking least squares support vector machine algorithm, and the prediction model was trained and evaluated, then combined with the model prediction error distribution law, the estimation method of threshold value and leakage volume was introduced for leakage detection. The results show that the average error between the model prediction and the actual water volume is low, the stability is high, and the combination of the prediction-threshold classification method can detect sudden leakage in a timely manner and estimate the leakage volume relatively accurately.

Evapotranspiration is a key process of energy exchange in the terrestrial-atmospheric system, and the selection of a suitable method for its accurate estimation is the basis and challenges to revealing the energy exchange process and the mechanism of Land-Atmosphere coupling under complex topographic conditions. Based on 60 years of meteorological data from 25 stations in the Red River Basin, China, the FAO56-Penman-Monteith method was used as a benchmark, and the MK statistical tests and Taylor diagrams were used to evaluate 8 potential evapotranspiration (PET) estimation methods from five aspeacts. The results show that the radiative methods Priestley-Taylor and Hargreaves had the best applicability, their results were closest to FAO (R²≈0.9); The temperature methods McCloud and Linacre were followed; The mass transport class methods Rohwer and Penman were worse. This study not only provided a highly adaptive PET estimation method for the Red River Basin, China, but also revealed the spatial and temporal distribution characteristics of the PET.

The lakes on Tibetan Plateau are expanding continuously, and the frequency and intensity of natural disasters (debris flow, glacial lake outburst) are increasing, which brings a series of challenges to water resources management, water disaster prevention and sustainable development in Tibetan Plateau and its downstream areas. Taking Yigong Lake as the research object, this paper establishes Tableland NDWI (TNDWI) based on 1 101 remote sensing images. Then the water surface morphology of Yigong Lake from 1986 to 2020 is reconstructed to analyze evalution process of historical water surface morphology in lake. The results show that the user accuracy of the TNDWI for the classification of plateau water bodies is higher than 96.70%, the overall accuracy is higher than 98.75%, and the Kappa coefficient is between 0.972 and 0.992, and the classification accuracy and consistency are better than the tranditional NDWI; The 2000 Yigong landslide has a significant impact on the evolution process of water surface morphology of Yigong Lake; Water surface area after dam-break reduces from 14.44±2.70 km² to 10.99±1.94 km²(P <0.001). Mann-Kendall mutation test results show that the change trend of water surface morphology has a mutation in 2000 (except in dry season); Morlet wavelet periodic analysis results show that the periodic oscillation law of lake area has gradually weakened since 2000. This study overcomes the lack of monitoring data of high altitude barrier lake, providing data basis for the ecological restoration and comprehensive treatment project of Yigong Lake as well as new idea for the quantitative study of the ecological environment in the region.

At present, the existing speed relays on the market only collect single signal source, poor anti-interference. It is easy to disorder the signal of the speed node output caused by measurement signal distortion and measuring channel fault. In order to improve the reliability and accuracy of the speed relay, two channels of residual voltage signals and two channels of sprocket speed measurement signals were respectively connected. Then the dual-probe tooth sequential speed measurement method was combined with the logic of selecting one out of three speed signals. The judgment method selected one speed signal as the main signal. In the signal output process of the rotational speed node, the limiting average filtering method and the method of retrieval interference output blocking were applied to eliminate the distortion in the signal output process. Through the simulation test bench test and the application in the actual generator set, the anti-interference ability of the acquisition signal loop, the signal measurement accuracy, and the reliability of the output action of the speed node have been significantly improved.

Urban water bodies play a vital role in maintaining the urban environment and development. In order to solve the problem of low transparency of its water body, taking Yaojiang River as the research object, the effects of solar radiation, turbidity, suspended solids concentration and particle size on water transparency were analyzed by means of comparative ratio, Pearson correlation analysis, and curve fitting calculation. The results show that the light intensity, solar elevation angle and azimuth angle affect the transparency monitoring. The stronger the light is, the greater the monitoring result of transparency is. Transparency (SD) is negatively correlated with turbidity (TUB) and suspended solids concentration (SS). Pearson correlation coefficients are -0.880, -0.570. After monitoring and calculation, the median particle size (d_50%) of Yaojiang River is between 15.5 and 61.3 μm. Filtration through a filter with a pore size of 10 μm can control the turbidity of the water body within 9.7 NTU and the concentration of suspended solids within 13.4 mg/L. The transparency of the Yaojiang River can reach 80 cm, which is the minimum requirement to maintain a normal aquatic environment.

In view of the problem of inconsistency and lack of real-time synchronization of data in each security zone with the increase of specialty system, this paper analyzed the cross-regional synchronization requirements of the Yalong River integrated hydropower management and control platform system, and proposed a simple, stable and reliable cross-regional synchronization system architecture based on the characteristics of unified construction and deployment of all specialty system based on the integrated platform. Real-time synchronization was achieved by intercepting the write operation context through the platform service gateway. The design realized the unified communication management and synchronization optimization of the professional data of the Yalong River integrated control platform system, effectively improved the performance and reliability of the system, and adapted to the future development of integrated system business of water, electric power and new energy dispatch.

In view of the problem that the current 180° turning pool of the fishway has poor flow condition and affects the fish's upward tracing, the water flow condition was improved by extending the length of the upstream and downstream of the turning section and adding the staggered guide plate. Based on the study of a certain vertical slot fishway, numerical simulation was used to research on the distribution of flow regime, velocity, turbulent kinetic energy and turbulent dissipation rate of four turning pool structures. The results indicate that extending the length of the upstream and downstream of the turning section and adding the staggered guide plate can effectively guide the mainstream to center, maintain the stability of the mainstream and avoid the formation of a large-scale recirculation zone, and it is beneficial to migratory fish. The results of this study can provide reference for the reconstruction and design of fishway.

The structure of fishway is the major factor that fish migrates successfully. The impact of pier head structure and horizontal interval of baffles on the hydraulic characteristics of a vertical slot fishway pool were researched. Twelve different working conditions were composed of two factors, namely, the diversion angle of pier head and the relative position of baffles. The RNG κ-ε turbulence model was used to simulate the hydraulic characteristics of fishway. The results indicate that the influence of pier head structure on hydraulic characteristics is mainly reflected on velocity and turbulent energy, and the smaller the diversion Angle, the smaller the velocity and turbulent energy are. The distance between flow deflector and baffler plate changed the mainstream flow pattern and area size, and then affected the distribution of flow velocity. When the relative position of b₀/L=0.15 or so, the flow pattern in the pool was reasonable, which met the basic requirements of fish migration.

In order to explore the water quality and pollution characteristics of the main water system in Chengde area, the monitoring data of 29 sections of Chengde surface water quality monitoring station from 2017 to 2020 were selected, and the water environment quality of the main water system in Chengde area was comprehensively evaluated by single factor evaluation, comprehensive pollution index and principal component analysis. The evaluation results show that generally speaking, the overall water quality of the main water system in Chengde is good from 2017 to 2020; From the perspective of time, the water quality of the main water system in Chengde in 2019 and 2020 was significantly improved compared with 2017 and 2018; From the perspective of space, the section pollution of Gonghou and Chenggang bridges is relatively serious. The water quality of the main water system in Chengde is mainly affected by the total phosphorus, COD and permanganate index.