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Influence of cascade reservoirs on spatiotemporal variations of hydrogeochemistry in Jinsha River

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Water Science and Engineering 2021年第2期14卷 97-108页

作者： Qiu-sheng Yuan Pei-fang Wang Juan Chen Chao Wang Sheng Liu Xun Wang Key Laboratory of Integrated Regulation and Resources Development of Shallow Lakes Ministry of EducationHohai UniversityNanjing 210098China

River hydrogeochemistry offers necessary guidance for effective water environmental ***,the influence of cascade reservoirs on river hydrogeochemistry remains *** this study,the Jinsha River,the headwaters of the Yangtze River of China,was selected to investigate the spatiotemporal variations of hydrogeochemistry after the construction of six cascade *** ions,total dissolved solids,electrical conductivity,and pH values of sampled water in the upper natural reaches and lower reservoir-regulated reaches were analyzed in both flood and dry *** results of Piper diagram and Gibbs plots showed that the hydrogeochemistry of the Jinsha River was naturally controlled by both evaporation-crystallization and carbonate weathering processes,but it was also artificially affected by *** impoundment of cascade reservoirs affected the hydrodynamic condition of the *** river flow in the flood season was reduced by approximately 24.5%,altering the proportions of water sources and leading to notable hydrogeochemical alterations in reservoir-regulated ***,river hydrogeochemistry generally remained unchanged in the dry season,owing to the insignificant effect of cascade reservoirs on river *** contrast to what has been observed in previous studies of individual reservoirs,the cumulative influence of cascade reservoirs on the Jinsha River flow regime did not cause abrupt hydrogeochemical changes between the upstream and downstream areas of each ***,the water quality assessments revealed that the impoundment of cascade reservoirs improved downstream irrigational water quality,with lower Naþratio values in the flood *** study provides the earliest evaluation of cascade reservoir influence on the hydrogeochemistry of the Jinsha *** findings of this study can be used as a reference for scientific guidelines for future environmental management of cascade reservoirs in large rivers.

关键词： River hydrogeochemistry Spatiotemporal variations Controlling factors cascade reservoirs Jinsha River

Identification of terrigenous and autochthonous organic carbon in sediment cores from cascade reservoirs in the upper stream of Pearl River and Wujiang River,southwest China:lignin phenol as a tracer

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Acta Geochimica 2022年第5期41卷 753-764页

作者： Li Gao Xin Lin Jun Fan Ming Yang Xueping Chen FushunWang Jing Ma School of Environmental and Chemical Engineering Shanghai UniversityShanghai 200444China Shimadzu(Shanghai) Global Laboratory Consumables Co.LtdShanghai 200233China

Organic carbon(OC)source attribution for cascade reservoir sediments has been identified as a critical gap in understanding the effective carbon sink of inland *** this study,nine sediment cores were collected from cascade reservoirs in the Wujiang and Pearl *** analyzed lignin phenol(Λ8),total organic carbon(TOC)content,and stable carbon isotopic composition(δC)of the sediments,focusing on the changes of terrigenous OC,and the variation of OC source in cascade reservoir sediments after *** results showed that theΣ8 and TOC contents decreased from upstream to downstream reservoirs,indicating the significant interception of terrigenous OC by cascade ***,theΛ8 content in the Pearl River reservoir sediments was much higher than that in the Wujiang *** the three-end-member mixing model,we estimated that OC in reservoir sediments mainly comes from soil and *** damming,the proportion of plankton OC in TOC slightly increased in seasonal and annual regulation reservoirs due to the limnetic evolution of the *** findings suggest that the cascade damming increases the interception capacity of the river to terrigenous OC and nutrients,and that slowing of water velocity caused by damming affected primary productivity and fluvial carbon cycling.

关键词： cascade reservoirs Terrigenous OC Lignin Autochthonous OC Three-end-member mixing model

Exploration and Practice on Joint Regulation of cascade reservoirs for Xiluodu-Xiangjiaba-Three Gorges

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Exploration and Practice on Joint Regulation of Cascade Rese...

梯级水库蓄水对三峡水库泥沙淤积滞后响应规律的影响

中国水利学会2016学术年会

作者： Wang Yuhua Three Gorges cascade Dispatch and Communication Center

As the core projects of West Power to East,Xiluodu and Xiangjiaba reservoirs were built and operated *** two reservoirs can enhance regulation and storage capacity of water resources in Yangtze River and also have an important significance for promoting flood resources utilization and optimal allocation of water ***,the dispatching and operating of these two reservoirs could change the hydrological situations of the lower *** variation appears more obvious in the farther downstream,which brings a new opportunity for improving comprehensive benefits of Three *** the construction of water and rainfall telemetric network stations and reservoirs information sharing platform,China Three Gorges Corporation carries out active exploration and practice in the field of joint operation of the cascade hydropower stations in Yangtze River in recent *** these measures which include joint operation of flood control,impounding water in advance and drawdown not only ensure the safety of the Yangtze River flood control,but also enhance the water use efficiency and clean energy production,play an important role in Yangtze River Golden Waterway,improve the ecological environment,promote the regional economic and social development as well as realize the harmony and unity of the economic benefits,social benefit and ecological benefits.

关键词： cascade reservoirs Joint Regulation Three Gorges

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Journal of Geographical Sciences 2023年第3期33卷 576-598页

作者：李昕任金秋许全喜袁晶张为 State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan 430072China Changjiang Survey PlanningDesign and Research Co.Ltd.Wuhan 430010China Hubei Key Laboratory of Basin Water Security Wuhan 430010China Bureau of Hydrology Changjiang Water Resources CommissionWuhan 430010China

Delayed response behaviour commonly occurs in conjunction with changes in riverbed scouring and sediment deposition and is a key component in understanding the intrinsic behaviour of reservoir *** to the complexity of the riverbed siltation process,the variability in the factors that influence siltation and the limitations of available research methods,the understanding of the delayed response behaviour of the sedimentation process in the Three Gorges Reservoir(TGR)is currently merely qualitative,and there is a lack of quantitative in-depth *** addition,the effects of changes in water and sediment conditions on sedimentation in the TGR before and after cascade reservoir impoundment have not been quantified,so further studies are needed to provide a reference for better understanding the intrinsic behaviour of sedimentation in the TGR and the implications for the long-term use of the *** on measured water and sediment data from 2003 to 2020 and topographic data from 2003 to 2018,a delayed response model for sedimentation in the TGR is constructed and combined with theoretical derivation to analyse the changes in the delayed response behaviour of the TGR before and after the impoundment of the cascade reservoirs and the associated ***,the influence of changes in water and sediment conditions in previous years on sedimentation in the reservoir area is *** results show that(1)the improved delayed response model of sedimentation,which considers variations in external water and sediment conditions,reservoir scheduling,and riverbed adjustment rates,can effectively reflect the sedimentation process in the TGR,especially after the impoundment of the cascade ***,the typical section elevation delayed response model can simulate the section elevation adjustment process.(2)After the impoundment of the cascade reservoirs,the decreased variation in incoming water and sediment and more concentrated incoming s

关键词： delayed response model sediment deposition Three Gorges Dam cascade reservoirs

Hydropower reservoirs on the upper Mekong River modify nutrient bioavailability downstream

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National Science Review 2020年第9期7卷 1449-1457页

作者： Qiuwen Chen Wenqing Shi Jef Huisman Stephen C.Maberly Jianyun Zhang Juhua Yu Yuchen Chen Daniele Tonina Qitao Yi State Key Laboratory of Hydrology-Water Resources & Hydraulic Engineering Nanjing Hydraulic Research Institute Center for Eco-Environment Research Nanjing Hydraulic Research Institute Department of Freshwater and Marine Ecology Institute for Biodiversity and Ecosystem DynamicsUniversity of Amsterdam Lake Ecosystems Group UK Centre for Ecology & Hydrology 5. Department of Eco-Environment Conservation Yangtze Institute for Conservation and Development 6. Center for Ecohydraulics Research University of Idaho

Hydropower development is the key strategy in many developing countries for energy supply,climate-change mitigation and economic development. However, it is commonly assumed that river dams retain nutrients and therefore reduce downstream primary productivity and fishery catches, compromising food security and causing trans-boundary disputes. Contrary to expectation, here we found that a cascade of reservoirs along the upper Mekong River increased downstream bioavailability of nitrogen and *** dams caused phytoplankton density to increase with hydraulic residence time and stratification of the stagnant reservoirs caused hypoxia at depth. This allowed the release of bioavailable phosphorus from the sediment and an increase in dissolved inorganic nitrogen as well as a shift in nitrogen species from nitrate to ammonium, which were transported downstream by the discharge of water from the base of the dam. Our findings provide a new perspective on the environmental impacts of river dams on nutrient cycling and ecosystem functioning, with potential implications for sustainable development of hydropower worldwide.

关键词： Mekong River cascade reservoirs downstream nutrient bioavailability nitrogen phosphorus

The different responses of planktonic bacteria and archaea to water temperature maintain the stability of their community diversity in dammed rivers

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Ecological Processes 2023年第1期12卷 365-378页

作者： Na Liu Baoli Wang Meiling Yang Wanzhu Li Xinjie Shi Cong-Qiang Liu Institute of Surface-Earth System Science School of Earth System ScienceTianjin UniversityTianjin 300072China Tianjin Bohai Rim Coastal Earth Critical Zone National Observation and Research Station Tianjin 300072China

Background Planktonic bacteria and archaea play a key role in river nutrient biogeochemical cycling;however,their respective community assembly and how to maintain their diversity are not well known in dammed ***,a seasonal survey of planktonic bacterial and archaeal community compositions and related environmental factors was conducted in 16 cascade reservoirs and corresponding river waters on the Wujiang River and the Pearl River in southwest China to understand the above *** Deterministic processes dominated bacterial and archaeal community *** structural equation models showed that water temperature can directly or indirectly affect the microbial ***,planktonic bacterial diversity increased with increasing water temperature,while archaea showed the opposite trend;the overall diversity of bacteria and archaea was no significant changes with changeable water *** microbes had a stronger distance–decay relationship than middle and rare ones,and the relationship was stronger in winter and spring than in summer and *** Planktonic bacteria and archaea in dammed rivers had different biogeographic distributions,and water temperature was a key controlling *** different responses of planktonic bacterial and archaeal diversity to water temperature could be due to their different phylogenetic *** ultimately maintained the stability of total microbial community *** study reveals the different responses of planktonic bacteria and archaea to water temperature and perfects the theoretical framework for planktonic microbial biogeography in dammed rivers.

关键词： Planktonic bacteria and archaea Community assembly Diversity Water temperature cascade reservoirs

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Dramatic sediment load changes and sedimentation characteristics upstream of the Three Gorges Dam due to the large reservoirs construction

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Frontiers of Earth Science 2024年第3期18卷 565-578页

作者： Jie LIU Wenwu ZHANG Ying SHEN Xin WANG National Inland Waterway Regulation Engineering Research Center Chongqing Jiaotong UniversityChongqing 400074China State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China School of River&Ocean Engineering Chongqing Jiaotong UniversityChongqing 400074China Tianjin Research Institute for Water Transport Engineering Tianjin 300456China

After the construction of cascade reservoirs in the upper reaches of the Three Gorges Reservoir(TGR),the sediment load outflow of the upper Yangtze River Basin(YRB)has been significantly altered,decreasing from 491.8 Mt/yr(1956–2002)to 36.1 Mt/yr(2003–2017)at Yichang *** has widely affected river hydrology,suspended sediment grain size distribution,and channel *** study analyzed hydrological variations in water discharge and sediment load of the upper YRB over the past 62 years(1956–2017)by employing a double mass *** variations in the source areas of sediment yielding for the upper YRB were quantified,and field measurement data of the cross-channel profile were collected to investigate the sedimentation process in the TGR from 2003 to *** than 90%of the sediment load reduction in the upper YRB may be explained by human *** Jinshajiang River was no longer the largest sediment source area for the Zhutuo station(accounting for 5.23%)in the 2013–2017 time span,and the sediment rating rates for the inflow and outflow of the TGR shifted to negatively correlated.A longitudinal fining trend was revealed in the suspended sediment ***,the mean median grain size of suspended sediment in the TGR had an increasing trend in the 2013–2017 *** result may be closely related to sediment regulation in reservoirs and incoming sediment load *** in the TGR decreased sharply from 299.8 Mt/yr in 2003–2012 to 47.2 Mt/yr in 2013–2017,but the sedimentation rate of the TGR remained at>80%***,some cross sections in the fluctuating backwater zone experienced scouring.

关键词： cascade reservoirs sediment load sedimentation characteristics suspended sediment grain size Three Gorges Reservoir

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乌江干流梯级水库运行对径流的影响