Changes of phosphorus delivery from Yangtze River to Dongting Lake under new water and sediment conditions

<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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Migration of Neolithic settlements in the Dongting Lake area of the middle Yangtze River basin, China: Lake-level and monsoon climate responses

The Holocene ◽

10.1177/0959683611405084 ◽

2011 ◽

Vol 22 (6) ◽

pp. 649-657 ◽

Cited By ~ 14

Author(s):

Tao Liu ◽

Zhongyuan Chen ◽

Qianli Sun ◽

Brian Finlayson

Keyword(s):

River Basin ◽

Yangtze River ◽

Lake Level ◽

Yangtze River Basin ◽

Dongting Lake ◽

Lake Area ◽

Monsoon Climate ◽

Dongting Lake Area ◽

Climate Responses ◽

China Lake

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Transmission and Prevention of Wuhan Coronavirus Disease 2019 (COVID-19) under Minimum Sunspot Number

Global Journal of Medical Research ◽

10.34257/gjmrfvol20is3pg13 ◽

2020 ◽

pp. 13-33

Author(s):

Tai-Jin Kim

Keyword(s):

Sunspot Number ◽

Harmful Algal Blooms ◽

Yangtze River ◽

Algal Blooms ◽

Migratory Birds ◽

Dongting Lake ◽

Uvb Radiation ◽

The Yangtze River ◽

Wholesale Market ◽

Mmr Vaccine

Porpoises, infected by Cetacean Morbillivirus from the feces of humpback whales in the East Sea, swam along the Yangtze River to reach Dongting Lake. Infected porpoises could be stranded and moved to Huanan Seafood Wholesale Market. Wuhan is low-lying and susceptible to flooding from the Yangtze River. Agricultural water in Hubei should prevent the harmful algal blooms for clean water. Sterilization by ultraviolet is recommended in air, water and confirmed patient with dialyzer to recover the Wuhan coronavirus disaster. The vaccine can be developed by culturing blood from CeMV infected porpoises in the Yangtze River or Dongting Lake, along with Wuhan coronavirus confirmed patient blood. Existing MMR Vaccine can be applied to cure the confirmed patient. CO2 emissions increased continuously with years (R2= 0.9497) causing high levels of UVB radiation on the Earth. Due to 11 years cycle of the sunspot number, there can be another dangerous outbreak at Dongting Lake with millions of migratory birds in China in coming years between 2030 and 2032.

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