Climatic and Anthropogenic Impacts on Water and Sediment Discharges from the Yangtze River (Changjiang), 1950–2005

<p>Bacterial communities are essential to the biogeochemical cycle in riverine ecosystems. However, the integrated biogeography and assembly process of planktonic and sedimentary bacterial communities in large rivers is still poorly understood. Here, the study provided the spatiotemporal pattern of bacterial communities in the Yangtze River of 4300 km continuum, which is the largest river in Asia. We found that the taxa in sediments are the main contributors to the bacterial diversity of the river ecosystem since sediments sub-group took 98.8% of the total 38, 904 Operational Taxonomic Units (OTUs) observed in 280 samples. Seasonal differences in bacterial communities were statistically significant in water, whereas bacterial communities in both water and sediment were geographically clustered according to five types of landforms: mountain, foothill, basin, foothill-mountain, and plain. Interestingly, the presence of two huge dams resulted in a drastic fall of bacterial taxa in sediment immediately downstream due to severe riverbed scouring. The integrity of the biogeography was satisfactorily interpreted by the combination of neutral and species sorting perspectives in meta-community theory for bacterial communities in flowing water and sediment. Although deterministic process had dominant influence on assembly processes in water and sediment communities, homogeneous selection was the main contributor in water, while combination of homogeneous selection and variable selection contributed selection process in sediment. In addition, homogenizing dispersal played more important role in community assembly process in sediment than water. Our study fills a gap in understanding of biogeography and assembly process of bacterial communities in one of the world&#8217;s largest river and highlights the importance of both planktonic and sedimentary communities to the integrity of bacterial biogeographic patterns in a river subject to varying natural and anthropogenic impacts.</p>

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Research on Characteristics of New Water and Sediment of Yichang Station after Impoundment of the Three Gorges

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.779-780.1613 ◽

2013 ◽

Vol 779-780 ◽

pp. 1613-1618 ◽

Cited By ~ 1

Author(s):

Yan Hua Yang ◽

Xiao Qiang Liu ◽

Hong Qian Zhang

Keyword(s):

Yangtze River ◽

Three Gorges Reservoir ◽

Test Method ◽

Rank Test ◽

Sediment Runoff ◽

Three Gorges ◽

The Yangtze River ◽

The Three Gorges Reservoir ◽

The Three Gorges ◽

Water And Sediment

Reservoir regulation and reservoir sedimentation make conditions of flow and sediment under the dam change greatly after impoundment of the Three Gorges Project. This paper analyzes change trend and abrupt change situation of incoming water and sediment and studies characteristics of new flow and sediment of Yichang Station after impoundment of the Three Gorges with Mann-Kendall nonparametric rank test method. The result indicates that operation of the Three Gorges Reservoir has leveled runoff process and shortened dry season and extended median water period. After operation of the Three Gorges Reservoir, annual sediment runoff and monthly sediment runoff of some months changed suddenly and sediment runoff reduced sharply in Yichang Station. Sediment entering the middle and the lower reaches of the Yangtze River decreases substantially and it almost can be regarded as clean water discharge. Intorduction After operation of 175m normal water level of the Three Gorges Reservoir, total storage capacity of the reservoir is about 43 billion m3. Most of incoming sediment in the upstream is intercepted and deposited inside the reservoir and clean water and muddy water containing non-bed sand discharges. Change of water and sediment conditions destroys balance of downstream river and causes bed-rebuilding of downstream channels. And this results in a serious of long-term and long distance changes, such as on-way recovery of sand content, undercutting of bed scour, expansion of bank erosion and decline of water table, etc.[1-. Yichang Station controls a drainage area of 1005501km2 in upstream of the Yangtze River and is a major flood source for the middle and the lower reach of the Yangtze River. Thus, water regime information of Yichang Station is significant to flood control of the middle and the lower reach of the Yangtze River, regulation of the Three Gorges Reservoir, construction of water conservancy project all across the Yangtze River, industrial and agricultural production and shipping, etc. On account of this, this article analyzes data about coming water and sediment of Yichang Station to support characteristics of new flow and sediment of Yichang Station after impoundment of the Three Gorges with Mann-Kendall nonparametric rank test method.

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Seasonal variation in water and sediment fluxes of the Yangtze River under precipitation change and human interference

10.5194/egusphere-egu21-1880 ◽

2021 ◽

Author(s):

Yao Yue ◽

Yuanfang Chai ◽

Shitian Xu ◽

Xiaofeng Zhang

Keyword(s):

Yangtze River ◽

Sediment Load ◽

Water Discharge ◽

Water Flux ◽

Precipitation Change ◽

The Yangtze River ◽

Human Interference ◽

Sediment Fluxes ◽

Water And Sediment ◽

Sediment Reduction

<p>Seasonal change of water and sediment fluxes is an important issue in flood/drought control and ecosystem protection. Based on trend analysis in dry and flood seasons during 1960&#8211;2014 at six major gauging stations on the Yangtze River, the largest river in China, significant homogenization of intra-year water discharge was found, while sharp decrease of sediment load in both seasons was tested. By reconstructing water and sediment series without the human interference, contributions of precipitation change, large dam constructions on the mainstream, and other human activities in each of the sub-basins of the Yangtze River were separated and quantified. It shows that precipitation change attributed for 9.5&#8211;23.6% to discharge homogenization in the middle and lower reaches of the Yangtze River, and increased sediment yield by 1.9&#8211;25.5% in both dry and flood seasons. Being the largest hydraulic project in the world, the Three Gorges Dam only explains 17.5&#8211;27.2% of the downstream homogenization in water flux, and 3.2&#8211;23.9% of sediment reduction in both seasons. Relatively small but massive human interference in the sub-basins was recognized as the primary factor, contributing over 60% to discharge homogenization and over 70% to seasonal sediment reduction, most notably in the Hanjiang sub-basin for water flux and in the Jianglingjiang sub-basin for sediment load.</p>

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Water and Sediment Quality in Lakes along the Middle and Lower Reaches of the Yangtze River, China

Water Resources Management ◽

10.1007/s11269-012-0093-2 ◽

2012 ◽

Vol 26 (12) ◽

pp. 3601-3618 ◽

Cited By ~ 38

Author(s):

Jinglu Wu ◽

Haiao Zeng ◽

Hong Yu ◽

Long Ma ◽

Longsheng Xu ◽

...

Keyword(s):

Yangtze River ◽

Sediment Quality ◽

The Yangtze River ◽

Water And Sediment ◽

Water And Sediment Quality

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Recent Evolution and Future Prediction of the Delta at the Yangtze River Mouth

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.353-356.2699 ◽

2013 ◽

Vol 353-356 ◽

pp. 2699-2704 ◽

Cited By ~ 1

Author(s):

Ming Li ◽

Yun Ping Yang ◽

Yi Tian Li

Keyword(s):

Mathematical Model ◽

Yangtze River ◽

River Mouth ◽

Sediment Discharge ◽

The Yangtze River ◽

Discharge Data ◽

One Dimensional ◽

Water And Sediment ◽

The Future ◽

The One

In this study, an empirical curve describing the relation between erosion and deposition rate and water/sediment discharge was developed based on the recent evolution trend of the submerged delta at the Yangtze River Mouth, and the one-dimensional mathematical model for unsteady water-and sediment-transport was calibrated using the water and sediment discharge data after water impounding to predict the water and sediment discharge for the future 10 years and the future evolution of the submerged delta at the Yangtze River Mouth. The results showed that the 10 m and 20 m isobaths areas of the submerged delta changed with the water and sediment discharge from siltation to siltation slowing down to erosion. Siltation increased with large amount of rain received by the watershed during 1997-2000, while continuous retreat of erosion happened during 2000-2009. Using the one-dimensional mathematical model for river water and sediment calibrated and tested with data collected after impounding, the water and sediment discharges were calculated for Series 60 and 90, and its evolution in 2013-2022 was predicted for the delta. For Series 60, its 10 cm and 20 cm isobaths areas showed alternative scour and siltation, while the delta showed trends of erosion. For Series 90, its 10 m and 20 m isobaths showed substantial siltation in flood years. The water and sediment discharges since the Three Gorges Reservoirs was filled were lower than the calculated results for both Series 60 and 90. If the water and sediment discharges continue to decease, the delta will take an erosion trend.

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Anammox response to natural and anthropogenic impacts over the Yangtze River

The Science of The Total Environment ◽

10.1016/j.scitotenv.2019.02.096 ◽

2019 ◽

Vol 665 ◽

pp. 171-180 ◽

Cited By ~ 12

Author(s):

Liming Chen ◽

Sitong Liu ◽

Qian Chen ◽

Guibing Zhu ◽

Xuan Wu ◽

...

Keyword(s):

Yangtze River ◽

Anthropogenic Impacts ◽

The Yangtze River

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Water and Sediment Exchange between the Yangtze River and the Poyang Lake, the Largest Freshwater Lake in China

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.675-677.865 ◽

2014 ◽

Vol 675-677 ◽

pp. 865-870

Author(s):

Hua Wang ◽

De Peng Song ◽

Ting Xu ◽

Rui Yang

Keyword(s):

Yangtze River ◽

Water Exchange ◽

Poyang Lake ◽

Water Current ◽

Water Volume ◽

The Yangtze River ◽

Water And Sediment ◽

The Common ◽

External Water ◽

Annual Water

In view of the complicated water and sediment exchange between Poyang lake and external Yangtze River, a 2-D unsteady numerical model with water current and sediment coupled was established. The hydrological condition in the common-water year (2010) was used for a yearly numerical simulation to investigate the water and sediment exchange mechanisms. The results showed that: The annual water volume flowing to the Yangtze River from Poyang Lake was about 2.17×1011 m3. Due to the periodical jacking influence of the external water level, about 1.06×1010 m3 water quantity flowed back into the Lake from the Yangtze River. The water exchange between Poyang Lake and the Yangtze River varied evidently with seasons, which was mainly concentrated in March and September. The annual sediment exported from Poyang Lake to the Yangtze River was about 1.53×107 t ,and the amount of sediment flowing back to the lake was about 1.89×106 t.

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Natural and anthropogenic forcing on the dynamics of virioplankton in the Yangtze river estuary

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315406013452 ◽

2006 ◽

Vol 86 (3) ◽

pp. 543-550 ◽

Cited By ~ 30

Author(s):

Nianzhi Jiao ◽

Yanlin Zhao ◽

Tingwei Luo ◽

Xiulin Wang

Keyword(s):

Yangtze River ◽

Anthropogenic Impacts ◽

River Estuary ◽

Distribution Patterns ◽

Yangtze River Estuary ◽

The Yangtze River ◽

Viral Abundance ◽

Estuarine Area ◽

Algal Virus ◽

River Estuarine

Seasonal investigation of virus dynamics by flow cytometry was conducted in the Yangtze river estuarine area in April, August, November 2002 and February 2003, and a supplemental investigation in the inner estuary and downstream of the river was conducted in October 2005. The majority of the total viral abundance was bacteriophage and only 5.4% of the total was algal virus. Total viral abundance varied with season and location, ranging from 6.75×105–1.68×107 particles/ml, and the virus:bacterium ratio (VBR) ranged from 1.52 to 72.02 with a mean of 8.7. In the present study, viral abundance peaked in both the summer and the winter, unlike the typical seasonal pattern reported in the literature, in which viral abundance peaks in the summer when bacterial hosts are also at their most abundant. However, the driving forces for the two peaks reported here were totally different, the summer viral abundance peak coupled with the development of bacterial hosts which were controlled largely by temperature year-round and by trophic state occasionally, while the winter one seemed to be multi-factor controlled. The host-phage interaction was no longer predominant in control of the winter viral abundance as bacterial abundance was lowest in this season. The winter low temperature would help maintain a high viral abundance as high temperatures might increase viral inactivation and viral decay; the VBR peak values actually occurred in the winter. More importantly, the high virus-containing freshwater discharge in winter due to a higher proportion of anthropogenic sewage relative to low natural flooding in winter run-off, turned out to be the first factor contributing to the high winter viral abundance and VBR values. In addition, the variation of intrusion of warm and relatively oligotrophic water from oceanic currents played a role alternating the distribution patterns of temperature, salinity and trophic conditions and consequently the distribution patterns of virus and bacteria seasonally and spatially. Dynamics of virus in the Yangtze river estuarine area is thus characterized by distinct seasonal and spatial variations due to natural forcing and by pronounced alternation of the regular patterns due to anthropogenic impacts.

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Polychlorinated Biphenyls in the Drinking Water Source of the Yangtze River: Characteristics and Risk Assessment

10.21203/rs.2.19713/v1 ◽

2019 ◽

Author(s):

Xiaoai Cui ◽

Jing Dong ◽

Zhifeng Huang ◽

Chengyou Liu ◽

Xiaocui Qiao ◽

...

Keyword(s):

Risk Assessment ◽

Drinking Water ◽

Polychlorinated Biphenyls ◽

Yangtze River ◽

Organic Pollutant ◽

Water Source ◽

Potential Ecological Risk ◽

Drinking Water Source ◽

The Yangtze River ◽

Water And Sediment

Abstract Background As the longest river in Asia, the Yangtze River flows through the most industrialized cities in China and provides critical ecological services for agriculture, industry, and transportation. Polychlorinated biphenyls (PCBs) have been banned for many years, but trace amounts of PCBs still exist as persistent organic pollutant in drinking water and are an ecotoxicological problem. In this work, we collected water, sediment, and suspended particulate matter (SPM) samples along the Yangtze River, to study the distribution and transport of PCBs for the risk assessment of the Yangtze River as a drinking water source.Results The ΣPCBs concentrations in water, sediment, and SPM ranged in 0.044–10.98 ng/L, 0.33–69.43 ng/g, and 0.72–152.66 ng/L, respectively. The main pollutants were PCB17, 18, 28, 47 and 118 in the Yangtze River. The ff SW value of PCB18 and PCB28 all exceeded 0.5, whereas the ff SW value of PCB47 and PCB118 (except for PCB118 at Y-4) were less than 0.5. The toxic equivalent quantity (TEQ) range of PCBs in water and in sediment was 0–5.55 pg-TEQ/L and 0–2.51 pg-TEQ/g, respectively.Conclusions In both water and sediment, lower chlorinated PCBs are dominant in the middle reaches and higher chlorinated PCBs are dominant at downstream. In contrast, SPM is dominated by tetra-CBs. The ff SW values reveal a net redissolution of lower PCBs from sediments to water but a net sorption of higher PCBs from water to sediment. The PCBs in water and sediment at downstream pose potential ecological risk, but the drinking water does not have a non-carcinogenic risk for humans.

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Polychlorinated Biphenyls in the Drinking Water Source of the Yangtze River: Characteristics and Risk Assessment

10.21203/rs.2.19713/v2 ◽

2020 ◽

Author(s):

Xiaoai Cui ◽

Jing Dong ◽

Zhifeng Huang ◽

Chengyou Liu ◽

Xiaocui Qiao ◽

...

Keyword(s):

Risk Assessment ◽

Drinking Water ◽

Polychlorinated Biphenyls ◽

Yangtze River ◽

Organic Pollutant ◽

Water Source ◽

Potential Ecological Risk ◽

Drinking Water Source ◽

The Yangtze River ◽

Water And Sediment

Abstract Background As the longest river in Asia, the Yangtze River flows through the most industrialized cities in China and provides critical ecological services for agriculture, industry, and transportation. Polychlorinated biphenyls (PCBs) have been banned for many years, but trace amounts of PCBs still exist as persistent organic pollutant in drinking water and are an ecotoxicological problem. In this work, we collected water, sediment, and suspended particulate matter (SPM) samples along the Yangtze River, to study the distribution and transport of PCBs for the risk assessment of the Yangtze River as a drinking water source. Results The ΣPCBs concentrations in water, sediment, and SPM ranged in 0.044–10.98 ng/L, 0.33–69.43 ng/g, and 0.72–152.66 ng/L, respectively. The main pollutants were PCB17, 18, 28, 47 and 118 in the Yangtze River. The ff SW value of PCB18 and PCB28 all exceeded 0.5, whereas the ff SW value of PCB47 and PCB118 (except for PCB118 at Y-4) were less than 0.5. The toxic equivalent quantity (TEQ) range of PCBs in water and in sediment was 0–5.55 pg-TEQ/L and 0–2.51 pg-TEQ/g, respectively. Conclusions In both water and sediment, lower chlorinated PCBs are dominant in the middle reaches and higher chlorinated PCBs are dominant at downstream. In contrast, SPM is dominated by tetra-CBs. The ff SW values reveal a net redissolution of lower PCBs from sediments to water but a net sorption of higher PCBs from water to sediment. The PCBs in water and sediment at downstream pose potential ecological risk, but the drinking water does not have a non-carcinogenic risk for humans.

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