In the design scheme of asphalt concrete core rockfill dam, the axis of diaphragm of dam foundation and asphalt concrete core wall is overlapped. However, due to construction errors and other reasons, the axis of diaphragm of dam foundation and asphalt concrete core wall may not be completely overlapped. Based on the finite element analysis method, the stress behavior of diaphragm of dam foundation and asphalt concrete core wall under different offsets was studied. The results show that under the superposition of axes, the local tensile stress of the diaphragm of dam foundation is in a state of no or small in the construction period and operation period, which has little influence on the whole. The minor offset of the axis of the diaphragm of dam foundation to the downstream will have a certain adverse effect on the stress of the diaphragm of dam foundation during operation. The main performance is that the local tensile stress of the downstream face of the diaphragm of dam foundation increases, and there is stress concentration. The local tensile stress increases by 3.6 times compared with that without offset. The concrete base of the asphalt concrete core wall can be slightly extended to the downstream according to the offset of the diaphragm of dam foundation, which can reduce the local tensile stress of the downstream surface of the diaphragm of dam foundation by 59.3 % and weaken the stress concentration, so as to improve the stress state of the diaphragm of dam foundation. The finite element simulation analysis can provide support for safety evaluation and selection of engineering treatment measures under eccentric condition of diaphram of dam foundation.

The water level of Poyang Lake is affected by both the Yangtze River mainstream and the Fiver Rivers (namely, Ganjiang River, Fuhe River, Xinjiang River, Raohe River and Xiushui River) in the lake basin. The runoff of the Five Rivers is the main inflow of Poyang Lake. In order to explore the temporal and spatial impact of the Five Rivers on the water level of Poyang Lake, the response of Poyang Lake level variation to the runoff change of the Five Rivers was quantitatively studied by data-driven simulation and sensitivity analysis. Firstly, the lake level prediction model was established by combining PSO-GA algorithm and support vector regression (SVR) technology. The temporal sensitivity of water level of Poyang Lake to runoff change of the Five Rivers was simulated. Then, based on this model, the spatial distribution characteristics of water level response of Poyang Lake to runoff change of the Five Rivers were studied using continuous model simulation. The results show that the most sensitive period that Poyang Lake level response to the runoff change of the Five Rivers is from May to July, especially in May. In terms of spatial distribution, water level in the middle part of Poyang Lake is most sensitive to the runoff change of the Five Rivers. For instance, based on the data in May 2010, when the runoff of the Five Rivers was increased by 40%, water level at Duchang station was averagely increased by 1.16 m within one week; Average water level increased at Xingzi station and Hukou station in the north lake area was 1.15 m and 1.03 m, respectively, and that at both Tangyin station and Kangshan station in the south lake area was 0.97 m. This study clarified the temporal and spatial response characteristics of water level of Poyang Lake to runoff of the Five Rivers, and provides scientific basis for water resources management and water projects optimization in the Poyang Lake basin.

In order to reveal the pollution characteristics of heavy metals in surface sediments in the upper reaches of the Zhanghe River, the chemical fractions and contents of Cr, As, Cd and Pb in 32 samples were determined. The potential ecological risks were assessed by rations of secondary phase and primary phase, and risk assessment code method. The correlation analysis was used to analyze the sources of heavy metals. The results show that the average contents of heavy metals Cr, As, Cd and Pb are 91.51±24.30, 9.81±3.05, 0.12±0.05, 18.30±5.43 mg/kg, respectively, and only the average contents of Cd do not exceed the background value. Only the content of Cd does not exceed the background value. The exchangeable fraction of Cd is larger than Cr, As, and Pb, and its biochemical activity is relatively high. The potential risks of heavy metals are sorted as Cd>Pb>As>Cr, and the risks are mainly concentrated in the source of Zhuozhang River and the west headwater of Qingzhang River. These four heavy metals mainly come from mineral exploitation, and mining activities contribute to the content and potential risks of heavy metals.

This study analyzed the mechanism of groundwater gushing from Quaternary boreholes at Aishan section of the lower reaches of the Yellow River in autumn floods. Groundwater level analysis, meteorological analysis, runoff analysis of the Yellow River, combined with isotopic analysis of groundwater and surface water samples were used. The results show that the average groundwater level was increased more than 3 m, which reduced the groundwater runoff. The increase of groundwater level was the basic factor of groundwater gusher. Continuous high water level of the Yellow River and the intensive water replenishment of the Yellow River to groundwater directly led to the groundwater gushing. The warning groundwater level of wells near Aishan section of the lower reaches of the Yellow River was 39.5 m within the 500 m outside the dike. This paper provides a basic understanding for preventing groundwater gushing from wells outside the levee of the Yellow River, and it is helpful for the protection of the levee of the Yellow River.

Water environment safety has always been an important issue that plagues the healthy development of country's social economy. Low-impact development technologies have good resilience in dealing with water environment safety issues. Taking Cangzhou China-Europe Green Industrial Park as the research object, the rainstorm flood model and the rainwater resource utilization benefit model were established. The study found that green roofs have an obvious control effect on ground runoff. The reduction rate and control rate of the total runoff are 56.31% and 68.32%, respectively, and the peak flow reduction rate is 48.58%. The control rate for pollutants of TP, TN, SS and COD is 72.92%, 74.82%, 74.44% and 73.89%, respectively. However, with the increase of rainfall intensity, the runoff control rate and the pollutant concentration control rate decreased, showing a significant negative correlation between the fourth and fifth power functions. After calculation, green roof can produce better economic and environmental benefits.

The evaluation of carrying capacity of water resources in the middle reaches of the Heihe River is important to promote the efficient use of water resources and sustainable economic development of the region. This paper quantitatively analyzed the dynamic changes of the water resources carrying capacity of the middle reaches of the Heihe River from 2000 to 2020 by selecting 10 evaluation indexes and using the fuzzy comprehensive evaluation model. The results show that the water resources carrying capacity of the region is between 0.3 and 0.5, with the highest value reaching 0.471 in 2020, and the water resources carrying capacities are in a bearable state. In order to improve the rational and efficient use of water resources, the middle reaches of the Heihe River should adjust the water use structure and strengthen the development of water-saving economy and ecological environmental protection.

Due to the frequent storage and discharge cycle of the reservoir, the cushion of the face rockfill dam of pumped storage power station should have good drainage performance, but when the face slab appears cracks, the cushion with low fine particle content may have the problem of seepage stability. Taking the concrete face rockfill dam of a pumped storage power station as an example, the inverted filtration test and seepage calculation and analysis were carried out, focusing on the filter protection mechanism of cushion material and transition material. The allowable crack width of the face slab was determined according to the damage slope of cushion material. The results show that after properly optimizing the fine particle content of cushion and transition material, the requirements of inverted filtration criterion can be met, and the allowable crack width of the panel is increased by 30% on the premise of ensuring the seepage stability of cushion.

Aiming at the problem of failure path analysis of high arch dams, the current numerical simulation methods still do not take into account the tensile and compressive damage characteristics of dam concrete. Therefore, the concrete damaged plasticity (CDP) constitutive model was used to analyze the damage and failure characteristics of the Laxiwa arch dam under the conditions of static overload, sudden temperature drop and maximum credible earthquake. The results show that the dam body mainly suffers from the tensile failure of concrete at the dam heel and bank slope dam foundation under overload conditions, and loses its bearing capacity after the damage penetration zone is formed; Under the condition of sudden temperature drop, the concrete of the dam body may cause tensile damage in the surface hole and the 1/4 arch dam crest, arch end and dam heel area; While under the earthquake condition, the surface hole near the crown beam of the dam crest downstream surface is mainly used for tensile damage. Tensile failure is dominant, and a horizontal band-shaped failure area is gradually formed and the bearing capacity is lost. The research results clarified the possible damage characteristics and failure paths of the Laxiwa arch dam, and provided a reference for determining the key parts of the Laxiwa arch dam structural safety monitoring analysis.

Investigating the effect of spacing on the effect of staggered-slip permeable spur dike on flow mitigation can provide a theoretical basis for the design of modern shore protection projects. The CCHE2D software was used to conduct a two-dimensional numerical simulation study of the solid flume model in the Xinqiman section of the Tarim River. And then the effect of different spacing on the water surface line, flow velocity and bed shear stress distribution in the upstream permeable spur dike area under the action of staggered-slab permeable spur dike was analyzed. When the relative dam length ratio is 0.21, and the inflow and dam length remain unchanged, the larger the spacing, the better the uniformity of flow and velocity behind the upstream permeable spur dike, and the lower the value of water level and shear stress in the riverbed. When the spacing is 5 times the effective dam length, the flow velocity, water level and riverbed shear stress behind the upstream permeable spur dike tend to be stable. The results of the study can improve the theory of flow mitigation effect in the action area of inserted permeable spur dike.

Pumped storage power station is the most mature large-scale energy storage tool in power systems. Because of its flexible peak and frequency modulation performance, it plays an important role in the novel power systems with new energy as the main body. The selection of upper and lower reservoirs is the key factor to determine its energy storage capacity and investment benefit in the process of site selection of pumped storage power station. However, the traditional site selection method of manual site investigation has the problems of heavy workload, low efficiency and easy leakage. In this paper, a method for site selection of upper and lower reservoirs of pumped storage power station based on satellite remote sensing terrain data was proposed, and experimental verification was carried out by Jinyun pumped storage power station in Zhejiang Province. The results show that the possible upper and lower reservoir construction areas within the target area can be efficiently screened out by using satellite remote sensing terrain data and computational intelligence techniques, which greatly improves the efficiency of site selection and shows the great application potential of satellite remote sensing in site selection of pumped storage power station.