scholarly journals Changes in Tundra Swan Cygnus columbianus bewickii distribution and abundance in the Yangtze River floodplain

2011 ◽  
Vol 21 (3) ◽  
pp. 260-265 ◽  
Author(s):  
PEIHAO CONG ◽  
LEI CAO ◽  
ANTHONY D. FOX ◽  
MARK BARTER ◽  
EILEEN C. REES ◽  
...  
Keyword(s):  
Water Quality ◽  
Yangtze River ◽  
Poyang Lake ◽  
Submerged Vegetation ◽  
Three Gorges ◽  
The Yangtze River ◽  
Vegetation Productivity ◽  
River Floodplain ◽  
Cygnus Columbianus ◽  
Tundra Swan

Approximately 75% of the East Asian Flyway Tundra Swan Cygnus columbianus bewickii population winters in the Yangtze River floodplain, China. Historically the species was more widely distributed throughout the floodplain but now most of the population is confined to five wetlands in Anhui Province and to Poyang Lake in Jiangxi Province, where the majority (up to 113,000 birds) occur. Within-winter counts suggest that swans congregate at Poyang Lake before dispersing to other sites later in the winter. Counts show large between-year fluctuations, but suggest declines at Shengjin and Fengsha Lakes (both in Anhui) during the last five years. Declines at Shengjin Lake are likely due to decreases in submerged vegetation (particularly tuber-producing Vallisneria, a major food item) perhaps linked to eutrophication. Range contractions throughout the floodplain may also be linked to reductions in submerged vegetation coverage elsewhere. Changes in water quality and lake hydrology post-Three Gorges Dam may have adversely affected submerged vegetation productivity. Key information needs for the effective implementation of conservation measures for Tundra Swans include: (1) annual surveys of all major wintering sites throughout each winter to establish the importance of different sites during the non-breeding period; (2) more information on swan diets at important sites; and (3) an assessment of adverse effects of water quality and lake water levels post-Three Gorges Dam on submerged vegetation productivity at Poyang Lake and other important sites.

scholarly journals Long-Term Impacts of Reservoir Operation on the Spatiotemporal Variation in Nitrogen Forms in the Post-Three Gorges Dam Period (2004–2016)

2021 ◽  
Author(s):  
Bei Nie ◽  
Yuhong Zeng ◽  
Lanhua Niu ◽  
Xiaofeng Zhang
Keyword(s):  
Water Quality ◽  
Reservoir Operation ◽  
Yangtze River ◽  
Ammonia Nitrogen ◽  
Three Gorges ◽  
The Yangtze River ◽  
Engineering Construction ◽  
Nitrogen Concentrations ◽  
Essential Nutrient

Abstract Nitrogen (N) is an essential nutrient limiting life, and its biochemical cycling and distribution in rivers have been markedly affected by river engineering construction and operation. Here, we comprehensively analyzed the spatiotemporal variations and driving environmental factors of N distributions based on the long-term observations (from 2004 to 2016) of seven stations in the Three Gorges Reservoir (TGR). In the study period, the overall water quality status of the river reach improved, whereas N pollution was severe and tended to be aggravated after the TGR impoundment. The anti-seasonal reservoir operation strongly affected the variations in N forms. The total nitrogen (TN) concentration in the mainstream of the Yangtze River continuously increased, although it was still lower than that in the incoming tributaries (Wu and Jialing rivers). Further analysis showed that this increase occurred probably because of external inputs, including the upstream (76%), non-point (22%), and point source pollution inputs (2%). Besides, different N forms showed significant seasonal variations; among them, the TN and nitrate nitrogen concentrations were the lowest in the impoundment season (October–February), and the ammonia nitrogen concentrations were the highest in the sluicing season (March–May). These parameters varied likely because of internal N transformation. Redundancy analysis revealed that the water level regulated by the anti-seasonal operation was the largest contributor. Our findings could provide a basis for managing and predicting the water quality in the Yangtze River.

scholarly journals Quantitative Assessment of the Influences of Three Gorges Dam on the Water Level of Poyang Lake, China

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1519 ◽  
Author(s):  
Dan Wang ◽  
Shuanghu Zhang ◽  
Guoli Wang ◽  
Qiaoqian Han ◽  
Guoxian Huang ◽  
...  
Keyword(s):  
Water Level ◽  
Yangtze River ◽  
Poyang Lake ◽  
Model Simulation ◽  
Water Storage ◽  
Three Gorges Dam ◽  
Three Gorges ◽  
The Yangtze River ◽  
Middle Reach ◽  
Significant Downward Trend

Lakes are important for global ecological balance and provide rich biological and social resources. However, lake systems are sensitive to climate change and anthropogenic activities. Poyang Lake is an important wetland in the middle reach of the Yangtze River, China and has a complicated interaction with the Yangtze River. In recent years, the water level of Poyang Lake was altered dramatically, in particular showing a significant downward trend after the operation of the Three Gorges Dam (TGD) in 2003, thus seriously affecting the lake wetland ecosystem. The operation of the TGD changed both the hydrological regime and the deeper channel in the middle reach of the Yangtze River, and affected the river–lake system between the Yangtze River and Poyang Lake. This study analyzed the change in the water level of Poyang Lake and quantified the contributions of the TGD operation, from the perspectives of water storage and erosion of the deeper channel in the middle reach of the Yangtze River, through hydrodynamic model simulation. The erosion of the deeper channel indicated a significant decrease in annual water level. However, due to the water storage of the TGD in September and October, the discharge in the Yangtze River sharply decreased and the water level of Poyang Lake was largely affected. Especially in late September, early October, and mid-October, the contributions of water storage of the TGD to the decline in the water level of Poyang Lake respectively reached 68.85%, 59.04%, and 54.88%, indicating that the water storage of the TGD was the main factor in the decrease in water level. The erosion of the deeper channel accelerated the decline of the water level of Poyang Lake and led to about 10% to 20% of the decline of water level in September and October. Due to the combined operation of the TGD and more reservoirs under construction in the upper TGD, the long-term and irreversible influence of the TGD on Poyang Lake should be further explored in the future.

How polluted is the Yangtze river? Water quality downstream from the Three Gorges Dam

2008 ◽  
Vol 402 (2-3) ◽  
pp. 232-247 ◽  
Author(s):  
Beat Müller ◽  
Michael Berg ◽  
Zhi Ping Yao ◽  
Xian Feng Zhang ◽  
Ding Wang ◽  
...  
Keyword(s):  
Water Quality ◽  
River Water ◽  
Yangtze River ◽  
River Water Quality ◽  
Three Gorges Dam ◽  
Three Gorges ◽  
The Yangtze River ◽  
The Three Gorges ◽  
The Three Gorges Dam

Experimental investigation on water quality standard of Yangtze River water source heat pump

2012 ◽  
Vol 66 (5) ◽  
pp. 1103-1109 ◽  
Author(s):  
Zenghu Qin ◽  
Mingwei Tong ◽  
Lin Kun
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
River Water ◽  
Heat Pump ◽  
Yangtze River ◽  
Water Source ◽  
Quality Standard ◽  
Heat Pumps ◽  
The Yangtze River ◽  
Water Conditions

Due to the surface water in the upper reaches of Yangtze River in China containing large amounts of silt and algae, high content of microorganisms and suspended solids, the water in Yangtze River cannot be used for cooling a heat pump directly. In this paper, the possibility of using Yangtze River, which goes through Chongqing, a city in southwest China, as a heat source–sink was investigated. Water temperature and quality of the Yangtze River in the Chongqing area were analyzed and the performance of water source heat pump units in different sediment concentrations, turbidity and algae material conditions were tested experimentally, and the water quality standards, in particular surface water conditions, in the Yangtze River region that adapt to energy-efficient heat pumps were also proposed. The experimental results show that the coefficient of performance heat pump falls by 3.73% to the greatest extent, and the fouling resistance of cooling water in the heat exchanger increases up to 25.6% in different water conditions. When the sediment concentration and the turbidity in the river water are no more than 100 g/m3 and 50 NTU respectively, the performance of the heat pump is better, which can be used as a suitable river water quality standard for river water source heat pumps.

scholarly journals Priority sites and conservation gaps of wintering waterbirds in the Yangtze River floodplain

2020 ◽  
Vol 30 (10) ◽  
pp. 1617-1632
Author(s):  
Shaoxia Xia ◽  
Xiubo Yu ◽  
Jinyu Lei ◽  
Richard Hearn ◽  
Bena Smith ◽  
...  
Keyword(s):  
Yangtze River ◽  
The Yangtze River ◽  
River Floodplain

Regulation of Laijiapu Waterway in Jingjiang Reach

2014 ◽  
Vol 501-504 ◽  
pp. 2001-2006
Author(s):  
Ya Liu ◽  
Li Zheng ◽  
Cheng Tao Huang ◽  
Zhao Biao Huang ◽  
Lin Liu
Keyword(s):  
Yangtze River ◽  
Three Gorges Reservoir ◽  
Three Gorges ◽  
The Yangtze River ◽  
Point Bar ◽  
The Three Gorges Reservoir ◽  
The Three Gorges ◽  
Before And After ◽  
The Stability ◽  
Channel Bar

After impoundment of the Three Gorges Reservoir, Jingjiang reach, in the middle of the Yangtze River, has gradually shown a series of atypical fluvial features, adversely affecting the maintenance of waterways. Citing the Laijiapu Waterway, a meandering segment in the lower Jingjiang for example, this paper compared the fluvial features of the channel before and after the impoundment, summed up its navigation-obstructing features, and proposed guarding the point bar on the convex bank and channel bar in the widening section as a key to maintaining the stability of the navigation channels.

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