Home Table of Contents

01 October 2021, Volume 38 Issue 10
    

  • Select all
    |
    RIVER-LAKE PROTECTION AND REGULATION
  • LU Jin-you, CHAI Zhao-hui, LIU Xiao-guang
    Journal of Changjiang River Scientific Research Institute. 2021, 38(10): 1-6. https://doi.org/10.11988/ckyyb.20210727
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The evolution of rivers and lakes of the Yangtze River and the change of human-water relation since the geological period were reviewed based on historical data, literature and measured data. The human-water relation in the Yangtze River basin has experienced a development process from harmonious coexistence to tension, and to deterioration and then relaxation. Both the Song Dynasty and the founding of P.R.C. characterized by industrialization and urbanization and the period after 2016 featured by the implementation of “great protection rather than great development” saw the turning points of the changes in human-water relation. The target of protecting the Yangtze River is to attain a harmonious coexistence between human and water, and to ensure the free movement in five channels, namely, water and sediment channel, flood discharge channel, navigation channel, ecological channel, and cultural channel. Three criteria for assessing the protection target were expounded as the health aquatic ecosystem of the Yangtze River, the good supporting function of the Yangtze River for human development, and a necessary and sufficient protection to the Yangtze River; the corresponding specific indicators were also given. In addition, the protection target for the current stage is to improve the human-water relation and reduce the negative impacts caused by the imbalance between human and water. Efforts in four aspects should be carried out: solving the problem of flood control safety, improving water environment, accelerating the restoration of water ecology, and ameliorating water culture construction.
  • DONG Yao-hua
    Journal of Changjiang River Scientific Research Institute. 2021, 38(10): 7-15. https://doi.org/10.11988/ckyyb.20210571
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Researches and practices on river & sediment and river regulation & flood control of the Yangtze River are comprehensively reviewed in terms of three aspects: theoretical researches on river & sediment, researches of river modeling and special study on flow & sediment, and practical application of river regulation & flood control. First, theoretical researches on river & sediment includes: river classification and morphology research such as stream-order gradation, river segmentation and river-regime-fitted grid, as well as sediment characteristics and movement while of demarcating grain size of river sediment, changes in runoff and sediment load, and methodological contrast between sediment budget and morphological change. Second, researches of river modeling and special study on flow & sediment consists of modeling on river flow and sediment transport and special studies on river and sediment, in which the modeling researches include development, applications and key technologies of river models, while the special studies give examples of essential features and numerical modeling of bend flow, features of cavity flow and sediment transportation and influence of physical model distortion, and impact of shoreline and island utilization on river-lake functions. Third, practical applications of river regulation & flood control comprises researches on large hydro-engineerings (e.g. Three Gorges Project, Gezhouba Project, and South-to-North Water Diversion Project), researches on major issues of river regulation, and practical application of flood control of the Yangtze River. Last but not the least, issues such as river research based on sediment, sediment research unlimited to river, and interaction between river and sediment should be enhanced, while interactive connection and achievement transformation between theoretical researches on river and sediment and practical application for river regulation and flood control should be also strengthened.
  • YAO Shi-ming, HU Cheng-wei, QU Geng
    Journal of Changjiang River Scientific Research Institute. 2021, 38(10): 16-26. https://doi.org/10.11988/ckyyb.20210586
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Under the influences of natural conditions and human activities, the downstream rivers of the Three Gorges Reservior have been experiencing changes in flow and sediment conditions and river evolution, which in the meantime pose new demands for flood risk management, navigation, electricity generation, water supply and ecology. It is urgent to investigate the mechanisms underlying the water and sediment transport and river evolution in the downstream of the Three Gorges Reservior, and develop novel ecological regulation technologies, by which to promote the fusions of river regulation and ecology protection. In this paper we make a review on previous studies of water and sediment transport, river evolution, and ecological regulation in the downstream of Three Gorges Reservior. In view of the deficiencies of current studies, we put forward the direction and contents of future research: the spatio-temporal variation trend of water and sediment in the downstream channel of the Three Gorges Reservior, the interaction between the reconstruction of different river types and water-sediment transport, the habitat restoration technology for damaged river bank, the ecological reconstruction technology for embankment, and the eco-friendly methods and technologies for river regulation.
  • WATER RESOURCES
  • XU Ji-jun, ZENG Zi-yue
    Journal of Changjiang River Scientific Research Institute. 2021, 38(10): 27-32. https://doi.org/10.11988/ckyyb.20210700
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    As the most important water resources allocation project in China, the South-to-North Water Diversion Project has been bringing great economic, social and ecological benefits to China via the First Phase of its Middle and East Routes. In the new era, the national development strategy, high-quality development and ecological civilization construction have posed higher requirements for the construction and development of the South-to-North Water Diversion Project. We analyzed and summarized the major achievements of and challenges as faced with the project, and discussed the ideas of water resources allocation which adapt to high-quality development and ecological civilization construction. Last but not the least, we put forward measures to boost the ecological benefits of the Middle and East Routes and suggestions of scheme comparison for the West Route.
  • HUO Jun-jun, YI Ming-qi, WANG Jing, JIANG Yu-ji
    Journal of Changjiang River Scientific Research Institute. 2021, 38(10): 33-39. https://doi.org/10.11988/ckyyb.20210584
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Located in the south-central part of the Tibetan Plateau, the Lhasa River Basin is one of the most sensitive areas to climate change due to its unique geographical location, and is also a densely populated and cultivated area on the Tibetan Plateau. The impact of climate factors and land use on runoff is quantified and analyzed in this paper by simulating runoff in the Lhasa river basin using different climate scenarios and land use conditions based on a SWAT model. Climate change and land use exerted an influence on runoff by approximately 82.95% and 17.05%, respectively. The main reason is that land use in the Lhasa River Basin has changed little over the last three decades, while temperature and precipitation have increased significantly. For every 10% increment in precipitation, basin runoff grew by about 11.8%, and the sensitivity of runoff to precipitation is of low spatial variability. For every 1 ℃ increase in temperature, basin total runoff increased by about 2.5% with significant spatial variability in runoff changes: runoff in the middle and upper reaches fell by 0.7%, while runoff in the lower reaches rose by approximately 3.6%.
  • YAO Li-qiang, SUN Ke-ke, XU Ji-jun, YUAN Zhe, QU Yan-ping
    Journal of Changjiang River Scientific Research Institute. 2021, 38(10): 40-47. https://doi.org/10.11988/ckyyb.20210569
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To reveal the regional overall drought degree and its change characteristics, a regional drought comprehensive index (MIDI) was constructed by using the dynamic weight coefficient method based on the calculation results of standardized precipitation index (SPI), standardized runoff index (SZI) and standardized regional water shortage index (SSDI). The applicability of MIDI was analyzed and verified according to historical drought statistics such as drought-affected area rate and reduced water supply due to drought. With the measured data of eleven meteorological stations and twelve hydrological stations of Changsha-Zhuzhou-Xiangtan region in recent decades as input, the drought events were identified by using run length theory and Copula function method, and their occurrence frequency was calculated. Furthermore, the evolution characteristics of regional comprehensive drought were analyzed by using trend analysis method. Results manifested that SPI, SZI and MIDI index have their own advantages in drought evaluation for different water sources and industry types. The annual cumulative drought intensity of SPI and SSDI is highly correlated with the rate of drought-affected crop area; while the annual cumulative drought intensity of SZI is highly correlated with urban water supply reduction due to drought, hence is more suitable for assessing the drought of urban area which is relied on surface runoff as the major water supply source. The dynamic weight coefficient method proposed in this study reflects the leading role of single drought index in different stages by taking the interannual change of regional industrial structure and the seasonal change of industrial water demand regularities into consideration. It is suitable for the comprehensive regional drought evaluation of various water sources and industrial types. Last but not the least, the MIDI of Changsha-Zhuzhou-Xiangtan region was examined from monthly, seasonal and yearly scales, and results unveiled that the frequency of extreme drought in Changsha-Zhuzhou-Xiangtan region has been increasing fluctuatingly in the recent two decades.
  • WATER ENVIRONMENT AND WATER ECOLOGY
  • LI Qing-yun, TANG Xian-qiang, LIN Li
    Journal of Changjiang River Scientific Research Institute. 2021, 38(10): 48-53. https://doi.org/10.11988/ckyyb.20210603
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In this paper we briefly introduce the development of the Basin Water Environmental Research Department (BWERD) of Changjiang(Yangtze) River Scientific Research Institute in the past decade since its inception, and systematically summarize its major achievements and innovations in science and technology. (i) A laboratory of water environment and ecology with complete functions has been established, based on which over 130 items related to water quality can be measured, including 109 items specified by Environmental Quality Standards for Surface Water (GB 3838—2002), and their measurement has passed China Inspection Body and Laboratory Mandatory Approval. Moreover, an advanced numerical simulation platform for basin water environment has been established and a pilot site for river and lake ecological restoration technologies has been set up. (ii) Characteristic achievements in scientific research include: multi-nonpoint source nutrients transport mechanism and ecological prevention practices based on water and sediment processes, impacts of rural hydropower on environment and ecology and corresponding measurements, eco-hydrological processes simulation and risk assessment of river-lake system connectivity, phosphorus transport patterns under water and sediment regulation in large reservoirs, occurrence characteristics and ecological risks of specific pollutants in typical regions of the Yangtze River Basin, habitat formation mechanism of fishes in the source region of the Yangtze River, changing patterns of river and lake environment in Plateaus, and monitoring, analysis, management, and protection of water quality in drinking water sources, etc. (iii) Main achievements in technology include: mobile water purification system for eutrophic water bodies in lakes and reservoirs, algae growth suppression technology based on micro-electric electrolysis, eco-hydrological remediation technology for cadmium contaminated soil, sterilization technology for rural decentralized water supply based on micro-electric electrolysis, and modification and resource utilization technology for copperflotation tailings, etc.. Last but not the least, we examine the shortages that have arisen in the development of the BWERD, and expect the focus of future research in the light of the current situation.
  • WATER-SOIL CONSERVATION AND ECOLOGICAL RESTORATION
  • LIU Ji-gen, DING Wen-feng, HUANG Jin-quan
    Journal of Changjiang River Scientific Research Institute. 2021, 38(10): 54-59. https://doi.org/10.11988/ckyyb.20210678
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Since the 1980s, notable progress has been made in scientific research of water and soil conservation in the Yangtze River Basin, providing scientific evidence to understanding the current situation of soil erosion in the basin, formulating soil and water conservation policy and planning, and implementing soil and water conservation. At present, China is in the crucial period of promoting the construction of ecological civilization. In view of this, we sum up the development process of soil and water conservation research, the key points and highlights of basic theory and key technology, as well as the construction of scientific research platform in the Yangtze River Basin. But overall, the scientific research foundation of soil and water conservation in the Yangtze River Basin is still relatively weak, the theoretical research still lags behind the practice of soil and water conservation. By clarifying future research priorities, that is, the dynamic mechanism and process of soil erosion, erosion prevention mechanism and applicability of soil and water conservation measures, restoration mechanism and technology research and development of degraded ecosystem, ecological process and effectiveness evaluation of major ecological treatment projects, our research would be of great significance to strengthening science and technology innovation and promoting the development of soil and water conservation in the Yangtze River Basin.
  • LI Jian-ming, ZHANG Chang-wei, WANG Zhi-gang, WANG Yi-feng, XU Wen-sheng, ZHANG Guan-hua, PU Jian, LIU Ji-gen
    Journal of Changjiang River Scientific Research Institute. 2021, 38(10): 60-68. https://doi.org/10.11988/ckyyb.20210582
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To obtain the erosion dynamic mechanism of spoil heaps, we examined the effects of taproot system (Artemisia gmelinii) and fibrous root system (Medicago sativa and Cynodon dactylon) vegetation on the runoff velocity, hydraulic parameters, and hydrodynamic parameters of the spoil heaps through artificial rainfall simulation experiment. Results demonstrated that vegetation reduced the average soil loss rate of spoil heaps by 88.34%-92.88%, as compared with bare spoil heaps. Average runoff velocity decreased by 50.51% under taproot system vegetation, and 21.32%-35.61% under fibrous root system vegetation. Both the runoff patterns of bare and vegetated spoil heaps were laminar (Reynolds Number <40). Runoff flow of bare spoil heaps was rapid when rainfall intensity was not greater than 1.2 mm/min; however, under the protection of taproot system vegetation, the runoff flow was slow, while under fibrous root system vegetation, the runoff flow pattern varied between rapid and slow regimes. Taproot system vegetation had a greater retardation effect on runoff resistance coefficient than fibrous root system. The flow shear stress and stream power could better describe the dynamic process of erosion on the spoil heaps under vegetation protection, showing a significant linear relationship (R2 was 0.63-0.96). Our findings offer scientific basis for revising the vegetation factors in the establishment of soil and water prediction model suitable for production and construction projects.
  • HU Yue, LU Yang, JIN Ke, ZHOU Huo-ming, WAN Dan, ZHANG Qian-zhu, YAN Jian-mei
    Journal of Changjiang River Scientific Research Institute. 2021, 38(10): 69-75. https://doi.org/10.11988/ckyyb.20210242
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Dry-hot valley is a special natural landscape in southwest China with extremely fragile ecological environment. The wide range, complex and diverse, as well as slow self-repairing of water-fluctuation zone add to the difficulty of ecological management of dry-hot valley. To clarify the development direction of ecological management of dry-hot valley, we introduce the basic situation of dry-hot valley, and systematically review the research progress of dry-hot valley in terms of soil types, physical and chemical properties, water distribution and vegetation restoration techniques, species selection, as well as water-fluctuation zone management. At present, the ecological management of dry-hot valley is in lack of long-term dynamic monitoring and has insufficient microscopic research as well as simple evaluation indicators for ecological restoration benefits. It is an urgent task to apply advanced technical approaches, rationally select good local plant species, and establish long-term dynamic monitoring and evaluation of the ecological environment system, strengthen the self-repair function of the ecosystem to achieve a more scientific and effective management.
  • FIELD INVESTIGATION AND OBSERVATION
  • XU Ping, HONG Xiao-feng
    Journal of Changjiang River Scientific Research Institute. 2021, 38(10): 76-81. https://doi.org/10.11988/ckyyb.20210572
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Field scientific observation and investigation is a fundamental scientific and technological work, and also a breakthrough point for independent innovation. In recent years, a field observation center has been established in the Changjiang (Yangtze) River Scientific Research Institute (CRSRI). A network system covering the Yangtze River Basin has been formed by setting up field scientific observation and research stations involving ecology, environment, resources, and disaster prevention. This paper presents a review on the continuous field scientific observations and multi-disciplinary comprehensive scientific investigations in the Yangtze River Basin by CRSRI. The achievements attained by CRSRI are also expounded in terms of basic conditions, observation results, scientific and technological support, backbone teams, and social influence. In future, CRSRI will focus on infrastructure construction, long-term observation and investigation, scientific research and demonstration, cooperation and exchange, and talent team construction, in order to provide support for the high-quality development of the Yangtze River Basin.
  • ENGINEERING SAFETY AND DISASTER PREVENTION
  • RAO Xi-bao, DING Jin-hua, YANG Xu-hui
    Journal of Changjiang River Scientific Research Institute. 2021, 38(10): 82-87. https://doi.org/10.11988/ckyyb.20210661
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Water works in China has entered an era of maintenance and management of hazards. Graded evaluation and repair for sick and hazardous water works conforms to the green and sustainable development concept and is conducive to improve the management level. In consideration of influential factors in five aspects as hazard degree, maintenance level, reparation technology feasibility, reparation cost, and hazard occurrence time, we analyzed the weights of each influential factor via expert judgment and order relation analysis method. The weight coefficient of hazard degree is the largest, followed by that of reparation technology feasibility and maintenance level in sequence. The occurrence time of hazard has the smallest weight. On this basis, we obtained the reparation necessity index (RNI), by which the necessity of maintenance and reparation can be evaluated.
  • HYDRAULICS
  • HUANG Guo-bing, YANG Wei, HOU Dong-mei, HU Han, LI Hui-ping, ZHANG Lu-chen, WU Shuang
    Journal of Changjiang River Scientific Research Institute. 2021, 38(10): 88-92. https://doi.org/10.11988/ckyyb.20210588
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In the upper and middle reaches of the Yangtze River, undesirable hydraulic characteristics and structural damage caused by flood discharge have emerged in some large-scale hydraulic projects. Characteristics of response to safety regulation are studied for flood discharge structures and other structures at the damsite. The disaster-causing mechanism of flood discharge damage is revealed, and the precise regulation technology is developed to reduce the threat of flood discharge. An intelligent and fast evaluation method is proposed, and a flood discharge safety monitoring and real-time operation system is established. The above evaluation method and monitoring system can be used for real-time monitoring, prediction, evaluation and optimization scheduling of flood discharge and energy dissipation protection, cavitation erosion, structural and field vibration, atomization and other response characteristics. The findings and corresponding technologies proposed in this study provide a well guidance for similar projects.
  • DUAN Wen-gang, HU Han, HOU Dong-mei
    Journal of Changjiang River Scientific Research Institute. 2021, 38(10): 93-98. https://doi.org/10.11988/ckyyb.20210549
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The flood discharge of high dam is accompanied by the transmission and release of energy. Up to now, examples of damage to discharge structures are still common. The flood discharge and energy dissipation of high dam is one of the key technologies for dam construction and operation. Eleven newly-built super-high arch dams with heights larger than 200 m in China since 2000 are taken as the main research objects. The layout of flood discharge and energy dissipation and hydraulic indexes of these super-high dams are among the top in the world. We systematically summarized their energy dissipation evaluation indexes, orifice shapes, flood discharge and energy dissipation layouts and hydraulic characteristics of plunge pool. On this basis, we further expounded three typical innovative modes of energy dissipation of dam body: Ertan mode with jets collided, Jinping mode with jets not collided, and Xulong mode with a combination of jets both collided and not collided. The research priority route and engineering application gradually changed from flood discharge and energy dissipation safety to the safety of flood discharge and the reduction of the atomization of bank slope, with the dynamic pressure in plunge pool smaller than 15×9.81 kPa(standard limit). The rapid development of super-high arch dam construction in the recent two decades has greatly promoted the technological progress and the innovation of flood discharge and energy dissipation mode in this field. We suggest further strengthen the research and development on numerical simulation of complex boundary and the research on the generation and release process of TDG for high dam flood discharge.
  • CAI Ying, LI Shu-you, HUANG Ming-hai
    Journal of Changjiang River Scientific Research Institute. 2021, 38(10): 99-103. https://doi.org/10.11988/ckyyb.20210115
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Hanjiang River Basin is subject to frequent floating aquatic plants which affect the ecological environment, power generation, shipping, and water supply. At present, the treatment of floating objects for hydropower projects mostly relies on human labor or mechanical action, which has safety problems and low efficiency. According to the characteristics of floating debris in Hanjiang River and the operation of Nianpanshan hydropower project, we adopt a hydraulic integrated floating raft at the approach channel to guide and discharge the floating debris to the sluice gate based on analyzing and comparing the load and structural safety and stability in the design schemes. The floating debris is discharged to the downstream through the sluice gate in due course. This developed technical equipment and the test results are conducive to the generation benefits of the power station and in the meantime ensure the safe operation of the project. The integrated hydraulic treatment adapts to the needs of various engineering and overcomes the difficulties in treating floating debris.
  • ROCK-SOIL ENGINEERING
  • WU Ai-qing
    Journal of Changjiang River Scientific Research Institute. 2021, 38(10): 104-111. https://doi.org/10.11988/ckyyb.20210677
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Based on the achievements of the rock mechanics major by professionals in Changjiang (Yangtze) River Scientific Research Institute in the past decade, this paper presents a review on the new developments of rock mechanics in hydraulic engineering and their applications. The contents include: fundamental theories and numerical methods, testing methods and technologies for rock mechanics, geo-stress measurement technique and methods for stress field simulations,geophysical and advanced detection technologies for rock masses,anchor support and reinforcement technologies for rock masses and structures, and their applications and practices in rock engineering. The forthcoming challenges in terms of understanding, utilizing and reinforcing rock masses in the profession of rock mechanics in hydraulic engineering are also expounded. The core issues of future research include: nonlinear properties of rock mechanics, continuous-discontinuous media mechanics, evaluation of cross-scale mechanical properties,multi-field coupling,and rock mechanics under dynamic conditions of high seismic intensity, etc.
  • WU Xin-xia, HU Ying-guo, LIU Mei-shan, ZHAO Gen, YANG Zhao-wei
    Journal of Changjiang River Scientific Research Institute. 2021, 38(10): 112-120. https://doi.org/10.11988/ckyyb.20210688
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The past two decades has seen the peak of hydropower construction in China. As the major approach of excavation and construction of water conservancy projects, blasting technology has achieved considerable development after the construction of many major hydropower projects. According to literature and documents in association with practical experiences and research results of large-scale projects in China, we made a review on blasting technologies in various hydropower engineering fields including the precise blasting control for foundation excavation of super-high arch dam, the key technology of excavation blasting control for hydraulic underground cavern, the key technology of blasting control for mining hydraulic graded material, and the intelligent blasting technology for hydropower engineering. With some engineering cases as examples, we emphasized the latest research progresses in the above-mentioned technical fields covering precise blasting and intelligent blasting for hydropower projects, and blasting and demolition of special hydraulic structures. The researches offer reference for the excavation and blasting control of similar projects in the fields of civil engineering, mining engineering, traffic engineering, and nuclear power engineering.
  • CUI Hao-dong, ZHANG Wei, SHENG Xiao-tao, RAO Xi-bao, WU De-xu
    Journal of Changjiang River Scientific Research Institute. 2021, 38(10): 121-125. https://doi.org/10.11988/ckyyb.20210548
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Having produced tremendous social benefits since its operation, the middle route project of the South-to-North Water Transfer has attracted increasing demands from areas along the route and in the Beijing-Tianjin-Hebei region. Maintenance of the channel with water cutoff would bring about risks; hence repairing the channel lining board and in the meantime maintaining water delivery poses a difficulty for engineers. Complicated seepage control measures were arranged under the lining board in some excavated channels with high-level groundwater. In emergency maintenance of the lining board at bottom or at deep by constructing cofferdam in the presence of water conveyance, engineers are faced with anti-floating problems and seepage failure possibly caused by the water level difference inside and outside the cofferdam foundation pit. In view of this, in line with the design of seepage control and cofferdam layout, we propose a seepage control plan for the cofferdam foundation pit: to block the permeable pipe of the canal foundation outside the cofferdam foundation pit, and to install water pump around the pit for drainage. Simulation results of the three-dimensional seepage field demonstrate that the horizontal permeability gradient and the water inflow of the foundation pit can be reduced remarkably by using the plan, hence ensuring the safety of foundation pit. The research finding offers theoretical basis and technical support for the emergency maintenance in the presence of water delivery.
  • ZOU Zhi-ke, LI Ya-long, YU Lei, LI Wei, LUO Wen-bing, SUN Jian-dong
    Journal of Changjiang River Scientific Research Institute. 2021, 38(10): 126-132. https://doi.org/10.11988/ckyyb.20210597
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The blockage caused by polydisperse particles in the process of stormwater recharge is in essence the transport and deposition of particles in porous media. To find deposition feature of polydisperse particles, a one-dimensional sand column test for artificial recharge is carried out to observe the outflow and inflow concentration of polydisperse particles ranging from 0.375 to 55.82 μm at five injection concentrations. A modified model in consideration of the particle polydispersity is theoretically derived based on the colloid filtration theory (CFT). Both the experimental and simulation results show the retention profiles of five concentrations compile with the hyper-exponential law, rather than the exponential retention predicted by the conventional model. The highly hyper-exponential retention profiles are caused by non-uniform deposition of polydisperse particles; and, the conventional model is found to homogenize the spatial distribution of retention of polydisperse particles. Local and overall permeability reductions are assessed by the Kozeny-Carman model. The blockage degree of media is directly relevant to particle size. The permeability of the medium is reduced to 52%, and the deposition of particles larger than 2.26 μm in the stormwater is the main cause of blockage.
  • WANG Zai-qin, LIAO Ling-min, LI Zhen, WEI Tao
    Journal of Changjiang River Scientific Research Institute. 2021, 38(10): 133-139. https://doi.org/10.11988/ckyyb.20210624
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Dam leakage treatment is a crucial work in the reinforcement of reservoir dam. The leakage problems caused by complex unfavorable geological bodies and concrete’s deep micro-cracks in water conservancy and hydropower projects are detrimental to the mechanical and seepage stability of reservoir dams. How to effectively deal with them still remains a huge problem in hydraulic engineering. Ordinary cement or ultra-fine cement grouting is often difficult to achieve the desired treatment effect, whereas chemical grouting appears a more effective technical approach. Under the background of some major national water conservancy and hydropower projects, Changjiang (Yangtze) River Scientific Research Institute has developed CW series high-performance chemical grouting materials and corresponding grouting equipment as well as fine control techniques over years of innovation, hence forming a complete set of novel chemical grouting technology for reservoir dam reinforcement. The technology has been applied to over 100 water conservancy and hydropower projects in China and abroad, which effectively ensures the safe operation and comprehensive benefits of projects, and produces huge social, economic and ecological benefits.
  • HYDRAULIC STRUCTURE AND MATERIAL
  • LI Zhen, FENG Jing, HAN Wei, SHAO Xiao-mei
    Journal of Changjiang River Scientific Research Institute. 2021, 38(10): 140-147. https://doi.org/10.11988/ckyyb.20210622
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Subjected to water pressure, water erosion, freeze-thaw or dry-wet cycles, hydraulic structures are prone to suffer from leakage, aging, dissolution damage and corrosion, which shorten the service life of the buildings. We present some new protective materials for the concrete in hydraulic structures: anti-seepage and anti-cracking coating materials containing fluorinated polyurethane and fluorinated modified polyaspartic acid ester polyurea developed by means of polymerization reaction or physical addition with polyurethane and polyurea as the matrix; environmental-friendly water-based fluorocarbon resin coating prepared by copolymerizing trifluorovinyl chloride with different vinyl ethers and vinyl esters; and abrasion-resistant materials developed by using polyurea and vinyl ester resin as the matrix composite with nano-sized or micron inorganic particles. The above series of seepage control, crack resistance, anti-aging, and abrasion-resistant materials have been applied to the concrete’s surface protection of Danjiangkou dam heightening project, the concrete’s impact-resistance of Three Gorges ship lock gate wall and other projects. Field test and long service have proved good effect. The achievements offer basis for the development of hydraulic protective materials and the optimization of material performance.
  • SHI Yan, LI Jia-zheng, DONG Yun, ZHOU Shi-hua, LIN Yu-qiang, CHEN Xia
    Journal of Changjiang River Scientific Research Institute. 2021, 38(10): 148-155. https://doi.org/10.11988/ckyyb.20210540
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    For over six decades, the material and structure department of Changjiang (Yangtze) River Scientific Research Institute has carried out systematic research on the development and application of mineral admixtures for hydraulic concrete, and applied high-quality fly ash to the construction of Three Gorges Project at large scale for the first time. We studied the impacts of new mineral admixtures such as phosphorous slag powder, limestone powder, natural pozzolan, etc. on the performance of hydraulic concrete. Our laboratory established a series of technical standards as well as a corresponding application technology system. Parts of the research achievements have been successfully applied in large and medium-sized water conservancy and hydropower projects, and are regarded as major basis for the selection of hydraulic concrete mineral admixture. In this paper we briefly introduce the research contents including the classification of hydraulic concrete mineral admixtures, the hydration mechanism of different cementing systems, the impact on the performance of hydraulic concrete, the design of mix proportion, and the construction techniques. We further sort related research results in the aim of promoting the development and application of new mineral admixtures in water conservancy and hydropower projects, providing important theoretical support for the design of hydraulic concrete, and improving the dam construction technology and development of hydraulic materials in China.
  • ZHOU Shi-hua
    Journal of Changjiang River Scientific Research Institute. 2021, 38(10): 156-160. https://doi.org/10.11988/ckyyb.20210237
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Wudongde Dam is the world’s first ultra-high arch dam to adopt low-heat cement in the whole dam. The cementitious material for dam concrete comprises low heat cement plus 35% grade-I fly ash. The performance of the dam concrete is of crucial importance to the safety of the project. We looked into the properties and developments of five-year age low-heat cement concrete of Wudongde Dam by examining the hydration performance of cementitious material, the mechanical performance, deformation performance, as well as adiabatic temperature rise of concrte. Our findings unveil that the hydration degree of the cementitious system amounts to 90.4% after three-year age, indicating the hydration process reaches a quasi-stable state. The ultimate compressive strength of dam concrete is 70.5 MPa, according to the development law, and the modulus of elasticity is about 42 GPa, the drying shrinkage around 380×10-6, and the autogenous volume deformation about 20×10-6. The low-heat cement concrete has higher long-term strength, equivalent elastic modulus and better long-term volume stability than medium-heat cement concrete under the same conditions. The final convergence value of adiabatic temperature rise is 27.9 ℃. The annual growth of adiabatic temperature rise is only 0.1 ℃ after three-year age, with no further abrupt rise in the later stage. In conclusion, the properties of Wudongde dam concrete gradually enter a slow convergence period after about one year, and basically reach stable after three-year age.
  • JIANG Ke, PANG Chao-ming, ZHANG Hui, LI Yang, CHEN Wei
    Journal of Changjiang River Scientific Research Institute. 2021, 38(10): 161-166. https://doi.org/10.11988/ckyyb.20210590
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Transport of moisture is the main cause of the durability problems of concrete. In the light of the similarity between concrete bulk and slice in terms of moisture transmission, we investigated into the law of moisture transport in the wetting process of concrete in pure water environment and salt solutions of different concentrations on the basis of parallel-tube adsorption theory and Washburn equation. Moreover, we also simulated the law of moisture transmission in the boundary layer of concrete taking concrete slices as the object. Our findings suggest that the wetting process of concrete’s boundary layer is dominated by capillary adsorption, and the existence of ions does not change the basic law, but only affects the transmission rate of moisture. The mass transmission model is fitted and verified through experimental data, and on this basis, the saturation change model of the concrete boundary layer is deduced, which appropriately describes the law of saturation change of the concrete boundary layer in one-dimensional transmission direction.
  • INFORMATION TECHNOLOGY APPLICATION
  • ZHENG Xue-dong
    Journal of Changjiang River Scientific Research Institute. 2021, 38(10): 167-173. https://doi.org/10.11988/ckyyb.20210623
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The water conservancy industry tends to be increasingly refined and intelligent since the rapid development of spatial information technology has driven the modernization of water conservancy. In this paper we made a comprehensive review on the application scenarios and development status of spatial information technology in the water conservancy industry, and analyzed the development trends and prospects of traditional 3S technology and a new generation of information technology in the water conservancy industry. Furthermore, we summarized the findings and typical cases of applying spatial information technology to many fields made by the Spatial Information Technology Application Department of the Changjiang (Yangtze) River Scientific Research Institute over the past two decades. Such application fields include: flood control, drought relief, disaster reduction, full-life cycle management of water conservancy projects, monitoring and assessment of the influence of water conservancy projects on ecological environment, river and lake management, dynamic monitoring of water and soil erosion. We also dissected future research topics, especially those regarding three-dimensional perception of water conservancy elements, comprehensive use of water conservancy-related big data, and the profound integration of artificial intelligence and water conservancy business.
  • CHEN Zhe, WEI Si-qi, WU Yi-bang, WEN Xiong-fei, XIANG Da-xiang, LI Jing-wei
    Journal of Changjiang River Scientific Research Institute. 2021, 38(10): 174-179. https://doi.org/10.11988/ckyyb.20210425
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    As the current mainstream Internet social media, Weibo allows its users to post information about events involved with the “River Chief System” anytime and anywhere on it. Extracting and classifying events improves the efficiency of discovering and solving problematic events in the management of river chief system, and also helps monitor and analyze the evaluation of the management status of river and lake shorelines for the people. The “Internet +” technology has been playing a tremendous role in the management of river chief system. In the present paper, the application of Weibo’s big data in the management of river chief system is discussed at first. A framework of text information mining system for Weibo is proposed based on the large amount of text description contained in social media. News and public information about events involved with river chief system can be captured by using Internet crawling technology and semantic recognition analysis technology via this framework. Tags of the events such as time, location, and type are identified and extracted, and finally people’s emotional tendencies are analyzed through data mining. With the data of Pearl River network from June 2018 to December 2020 on Weibo as a case study, the correctness of the model in training set reaches 88.6%, implying the feasibility of the model. The public opinion analysis system can help improve the management efficiency of the river chief system.
  • INFORMATION TECHNOLOGY APPLICATION
  • HUANG Yue-wen, NIU Guang-li, LI Duan-you, HAN Xiao, ZHOU Hua-yan
    Journal of Changjiang River Scientific Research Institute. 2021, 38(10): 180-185. https://doi.org/10.11988/ckyyb.20210589
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Monitoring on reservoir and dam safety is an important guarantee for the safe operation of project. It is urgent to improve the ability of dam safety monitoring by using the new generation of information technology. In this paper we systematically summarize the researches and applications made by Changjiang (Yangtze) River Research Institute in intelligent perception and intelligent management technology of dam safety monitoring in recent years. We built a unified data resource pool for dam safety monitoring by developing a series of intelligent sensors, intelligent acquisition units and Internet of things sensing platform, and developed a generalized safety monitoring cloud service system. We also built professional data mining platform and comprehensive visualization application to realize the full link application of data perception, transmission, management, analysis and display for dam safety monitoring, forming a full life cycle intelligent solution for dam safety monitoring. The research achievements have been applied in more than 100 water conservancy and hydropower projects, such as Wudongde, Xiluodu, Xiangjiaba and Datengxia hydropower stations, playing an important supporting role in ensuring the safety of project construction and operation.
  • INSTRUMENTATION DEVELOPMENT AND TESTING TECHNIQUES
  • JIA Bao-liang, LUO Yi, ZHANG Hui, GUO Liang
    Journal of Changjiang River Scientific Research Institute. 2021, 38(10): 186-191. https://doi.org/10.11988/ckyyb.20210662
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Since cement grouting project is a hidden work, it is difficult to check and control the grouting quality directly. Automatic monitoring of the grouting parameters is thus very crucial. In this paper we made a review on the technological progresses and the process of developing automatic grouting recorder, and expounded the development of digital grouting monitoring system. Also we looked into the future of intelligent grouting recorder, intelligent monitoring cloud platform, anti-counterfeiting of online monitoring data, as well as BIM+GIS-based monitoring system integrating latest achievements of modern electronic technology, Internet of Things technology, big data technology, and blockchain technology. The intelligent monitoring systems are beneficial for the safety and quality of hydropower projects, and will reduce cost and promote the management of project construction.
  • PAN Xi-he, HUANG Ye-hua, NIE Wei, FANG Bin-chen, YAN Guo-qiang, CHENG Yuan-chu
    Journal of Changjiang River Scientific Research Institute. 2021, 38(10): 192-198. https://doi.org/10.11988/ckyyb.20210636
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    At present, China’s hydropower industry has entered a new stage of high-quality development. In this paper we made a review on the technical status in two professional fields, namely, turbine governor and synchronous motor excitation. We introduced the progresses made in control theory research and regulation mode of special turbine, and expounded the main technical characteristics of dual-core excitation regulator. Moreover, we summarized the major achievements of Changjiang (Yangtze) River Scientific Research Institute in technology innovation, product innovation and industry standard formulation for hydropower unit control equipment in the past decade, and looked into the prospect of hydroturbine governor and synchronous motor excitation technology to make greater contribution to carbon peak and carbon neutrality goals. Hydroturbine governor and synchronous motor excitation should be autonomous and controllable, and must be improved in terms of reliability and intelligence.
  • READER·AUTHOR·EDITOR
  • JIANG Xiao-lan, LAI Yue-qiang, LIU Yun-fei, HUANG Ling
    Journal of Changjiang River Scientific Research Institute. 2021, 38(10): 199-206. https://doi.org/10.11988/ckyyb.20210749
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In order to commemorate the 70th anniversary of the establishment of Changjiang (Yangtze) River Scientific Research Institute in 2021, we analyzed indicators of Journal of Yangtze River Scientific Research Institute over the past decade. Such indicators include: received and published number of papers, impact factor, structure of author group, fund ratio of paper, and etc. Moreover, we expounded the discipline of papers, role of editorial board, source of quality papers, and summarized our efforts and innovations in cracking down academic misconduct, developing new media coverage, constructing editorial team, and made a review on the achievements of the Journal. Over the past decade, the Journal has leaped forward in many aspects: the received and published number of papers surged by 191% and 41%, respectively; the composite cited frequency and impact factor boosted by 146% and 74%, respectively; other indicators of the Journal also made steady strides. The study is expected to better promote progresses in water science and technology, and serve social-economic development by enhancing the quality of the Journal.