The Gan-Yue Canal is an important component of the third vertical Zhejiang-Jiangxi-Guangzhou channel in the national high-level waterway network "four vertical-four horizontal-two networks" planned by the National Comprehensive Three-dimensional Transportation Network Planning Outline. Whether the canal shipping water can be guaranteed is one of the important questions that must be answered clearly. Starting from the general situation of the Ganjiang River and Beijiang River basins involved in the Gan-Yue Canal and the basic situation of water resources development and utilization, according to the prediction of the number of gates passing through the Gan-Yue Canal and the layout scheme of the ship lock, the daily average theoretical water consumption calculation of the ship locks of each cascade hub of the canal was carried out so as to calculate the shipping water consumption and water shortage of the Gan-Yue Canal. Combined with the "Jiangxi Water Network Construction Plan", the combination scheme of normalized daily water supply of step-by-step cyclic water lifting + emergency water supply of Jifu Reservoir ( Chongxian Dam Site ) was recommended. This paper holds that the scheme of taking corresponding measures, such as water-saving technology for locks, step-by-step water lifting, and water replenishment for reservoirs, can meet the water supply demand of the cascade of water shortage hubs and solve the problem of insufficient shipping water resources in Gan-yue Canal Project. Finally, the research directions for deepening the water supply guarantee plan of shipping have been proposed.

Water body health assessment is an important tool and key means for diagnosing the functional status of ecosystems. In view of the ecological characteristics of river-type reservoirs, taking Xiluodu Reservoir as an example, a multi-dimensional health evaluation system integrating water environment, water ecology, sediment environment and water dynamics has been constructed. The framework comprises four subsystems of water environment, water ecological structure & function, sediment environment, and hydrodynamics. Nine specific indicators (under 6 criteria) including water quality, trophic status, phytoplankton, organic pollution, heavy metal pollution, and flow velocity, are chosen for quantitative evaluation. The results show that the reservoir's comprehensive health index in 2023 was 80.9, indicating an overall "Good" status. Significant spatial heterogeneity exists, upstream areas consistently outperformed mid-downstream sections, where reduced flow velocity elevates algal bloom risks, warranting management attention. While the water and sediment environments were relatively favorable, constrained hydrodynamics and low phytoplankton biomass were the key limiting factors for ecosystem health. The assessment results align closely with the observed ecological conditions, demonstrating the framework's practical applicability for health evaluation in similar river-type reservoirs.

Currently, urban wet weather overflow pollution has become one of the key factors restricting the improvement of urban water environment quality. Conducting research on the traceability of overflow pollution is of great significance for revealing the output patterns of pollutants and achieving precise control of overflow pollution. This study systematically monitored the overflow sewage at an overflow outlet of the Qinghe River in Beijing and the surface runoff in the nearby area in July 2024. Three-dimensional excitation-emission matrix fluorescence spectroscopy (3D-EEM) combined with parallel factor analysis (PARAFAC) was employed to trace the sources of dissolved organic matter (DOM) in the overflow sewage. The results indicate that the pollutant concentration in surface runoff is higher than that in overflow sewage at the initial stage of rainfall. However, as the rainfall continues, the pollutant concentration in surface runoff gradually decreases and eventually becomes lower than that in overflow sewage. Three fluorescent components are detected in the overflow sewage, namely, the fulvic acid-like component C1, the mixed component C2 of aromatic protein-like substances and humic acid-like substances, and the tyrosine-like component C3, accounting for 37.20%, 49.29%, and 13.51% of the total fluorescent components, respectively. The traceability analysis further reveals that pipeline sediments contribute the most to the DOM in overflow sewage, representing its primary source.

Chlorophyll-a is a key indicator for assessing lake water quality, but traditional point-based water quality monitoring has limitations. Remote sensing technology can provide large-scale and dynamic water quality monitoring. Therefore, utilizing multispectral remote sensing technology and considering the spectral band characteristics of the Sentinel-2 satellite, three-band and four-band chlorophyll-a concentration inversion models were constructed based on ground-measured data. The leave-one-out cross-validation method was adopted to validate the model accuracy. The optimal model was applied to monitor the chlorophyll-a concentration in Chaohu Lake from 2019 to 2023. GIS spatial analysis and statistical methods were combined to systematically analyze the spatiotemporal variation characteristics of chlorophyll-a concentration in Chaohu Lake. The results showed that the three-band model based on b₄/b₅/b₇ achieved the highest inversion accuracy. For the Sentinel-2A and Sentinel-2B three-band models, the determination coefficients (R²) were 0.763 and 0.766, the mean relative errors (M_MRE) were 16.87% and 16.66%, and the root mean square errors (R_RMSE) were 4.26 μg/L and 4.22 μg/L, respectively. Spatiotemporal analysis revealed that over the past five years, the chlorophyll-a concentration in Chaohu Lake exhibited significant spatial heterogeneity characterized by higher levels in the west and lower levels in the east, and seasonal fluctuations characterized by higher concentrations in summer and autumn and lower concentrations in spring and winter. An overall decreasing interannual trend was observed, and the inversion results were consistent with the water quality monitoring data for Chaohu Lake. The improved chlorophyll-a concentration inversion model established in this study demonstrates good accuracy and strong applicability. The proposed research method is feasible and effective, providing robust technical support for the monitoring, evaluation, and management of inland Type II water bodies such as Chaohu Lake using remote sensing.

To investigate the impact of vegetation on the motion characteristics of porous jet flow, the Realizable κ-ε turbulence model was adopted to analyze the influence laws of the jet-cross-flow velocity ratio and jet spacing on the motion characteristics of the momentum jets arranged in series in vegetated river channels from the aspects of flow velocity distribution, vortex morphology and jet trajectory, respectively. The results show that vegetation inhibits the horizontal expansion of the jets and promotes their vertical spread. At low jet-to-crossflow velocity ratios, the front jet suppresses the vertical diffusion of the rear jet, while at high jet-to-crossflow velocity ratios, the shading effect of the front jet on the rear jet is significant, allowing the rear jet to diffuse to higher positions. This study can provide theoretical guidance for the design and optimization of wastewater discharge in vegetated channels.

To investigate the influence of guide vane height on downstream helical flow in a guide-vane swirl generator, numerical simulations and physical experiments were combined. Five swirl generator models with varying guide vane heights were designed to systematically analyze circumferential velocity distribution, streamwise evolution of mean circumferential velocity, and helical flow attenuation characteristics. Results indicate that the downstream circumferential velocity follows a counterclockwise rotational distribution. With increasing guide vane height, the distribution regions of circumferential velocity and angular momentum were observed to expand significantly, resulting in enhanced helical flow intensity. The mean circumferential velocity was found to decay exponentially along the streamwise direction, though its attenuation rate showed minimal dependence on guide vane height. At a fixed downstream cross-section, the mean circumferential velocity increased with guide vane height, but this growth rate decreased progressively. When the height exceeded 35 mm, further increases had negligible effects on velocity enhancement, suggesting optimal swirl generation at 35 mm. These findings provide a theoretical foundation for the structural optimization of guide-vane swirl generators.

The river water surface profile serves as a fundamental basis for the construction of hydraulic engineering structures including levees, sluice gates, and pumping stations. In recent years, the river regime in the Middle and Lower Reaches of the Dongjiang River has changed greatly, and the extreme storm surges occur frequently in estuaries, resulting in a rising trend of the design tidal level. To study the water surface profile of the middle and lower reaches of the Dongjiang River and delta river network area under the new situation of changing boundary conditions, a one-dimensional hydrodynamic mathematical model is built based on MIKE11 software with the latest measured terrain data and design tide level. The floods in June 2022 and June 2020 are used to calibrate and verify the model. The water surface profiles of the middle and lower reaches of the Dongjiang River and the delta river network areas are calculated. The maximum water level error of calibration and verification of the model is within 0.1 m, and it can simulate the hydrodynamic conditions well. That the undercutting of the middle and lower reaches of the Dongjiang River leads to a downward trend in the water level under the same flow, and the rising design tidal level leads to the rise of water level in the lower reaches of the river network area.The change of water surface profile is in line with the actual situation. The research results can provide reference for the engineering design of embankment, water gate and pumping stations in the Dongjiang River and delta network river area.

Currently, the method of preventing siltation of water intakes in mountain rivers is a passive measure, i.e., allowing the unit to be shut down and then manually dismantling and cleaning the filter elements. This method is inefficient and time-consuming with poor safety. A new type of rotary filter is proposed to address the problems of easy clogging and high maintenance cost of traditional basket filters. FLUENT was used to establish a three-dimensional water flow mathematical model to simulate the changes in the flow and pressure fields inside the filter under the conditions of clear and muddy water, and the head loss of the traditional basket filter and rotary filter was analyzed. Compared with the traditional basket filter, it shows that the rotary filter can effectively slow down the silt fall, improve the water capacity of the filter, and effectively extend the working time of the filter. The study can provide design reference and theoretical basis for the improvement and optimization of water intake filters in mountainous rivers.

The CSGR dam of Shaping I-stage is the first application of cemented sand gravel and rock dam construction technology in the main project of large hydropower station, and its supporting design system still has many technical points to be improved. In this paper, theoretical analysis, physical tests, numerical simulation and engineering research methods were used to study the structure and structural design of the CSGR dam. The results show that the section of the CSGR dam is determined comprehensively according to the foundation conditions and dam building materials, and the single safety factor method is recommended for structural calculation; The zoning of the dam body should be divided according to functional requirements, and the rich slurry cemented sand gravel and rock can be used as the anti-seepage protective layer on the dam surface; Generally, the dam body is not provided with longitudinal and transverse joints, and transverse joints can be provided when the building layout needs and the construction strength is restricted; The anti-seepage protection layer of the dam should be equipped with transverse joints; Waterstop shall be set at the contact part between the dam transverse joint and the river to protect the internal CSGR; Temperature control measures may not be taken for the CSGR dam. The research results have accumulated valuable experience for the application of the CSGR dam construction technology in large and medium-sized projects.

The presence of near-field fracture clusters plays a critical role in governing the mechanical behavior of fracture initiation during hydraulic fracturing processes. This study systematically investigates the mechanical properties and fracture propagation mechanisms in granite through uniaxial hydraulic fracturing tests, acoustic emission monitoring, and digital image scanning techniques. Statistical analysis of the experimental data shows that near-field fracture clusters induce significant reductions in fracture initiation pressure, acoustic emission activity, and energy dissipation, all of which follow an exponential decay pattern. When fracture density exceeds two cracks, the attenuation rate of the cracking pressure has decreased significantly, indicating a diminishing influence of fracture quantity on pressure reduction. Fracture surface morphology exhibits statistically significant variations under different fracture cluster configurations, with fractal dimension demonstrating a positive correlation with fracture density. The increasing complexity of fracture surfaces with higher fracture density is characterized by a negative linear relationship between fractal dimension and initiation pressure.