Non-Uniform Sediment Input of the Middle Yangtze River, China

2014 ◽  
Vol 641-642 ◽  
pp. 70-74
Author(s):  
Hua Ge ◽  
Ling Ling Zhu ◽  
Ren Yong Huang
Keyword(s):  
Human Activities ◽  
Yangtze River ◽  
Three Gorges Reservoir ◽  
Normal Operation ◽  
Main Stream ◽  
Three Gorges ◽  
Upper Yangtze River ◽  
Sediment Input ◽  
Lower Yangtze ◽  
The Upper Yangtze River

The non-uniform sediment input has played a significant role in the bed evolution in the middle and lower Yangtze River, which indirectly influences the amount of the sediment transported into the East China Sea every year. However, it has been dramatically changed by the climate change, especially the human activities in the upper Yangtze River, not only the amount, but also the grading. The average annual sediment load has reached to 402.6 million tons since 1960s, while showing a decreasing and refining trend mostly influenced by the human activities, such as soil and water conservation, and large hydropower projects. The most direct consequence of these changes was to cause severe erosion in the middle and lower Yangtze River, further to bring about fluvial regime adjustment. In this article, a series of daily and annual averaged sediment transport data since 1960’ were collected and analyzed to find the impacts of the significant human activities on the non-sediment input of the middle Yangtze River, and then its variation tendency was predicted, affected by the existed large hydropower projects and to be build ones in the upper Yangtze river. The result shows that the non-uniform sediment input of the middle Yangtze River was slightly reduced by the operation of Gezhouba Project and the up and middle Yangtze River water and soil conservation prevention and control projects, and further less after the impoundment of Three Gorges Reservoir, meanwhile its grading has been getting finer and finer. In future, along with the normal operation of the Three Gorges Reservoir and the built of the cascade reservoirs in the upper main stream and tributaries of the Yangtze River, it will be continuously reduced and refined.

scholarly journals Spatiotemporal Distribution and Species Composition of Fish Assemblages in the Transitional Zone of the Three Gorges Reservoir, China

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3514
Author(s):  
Pengcheng Lin ◽  
Lin Chen ◽  
Xingchen Gao ◽  
Chunling Wang ◽  
Xin Gao ◽  
...  
Keyword(s):  
Fish Species ◽  
Yangtze River ◽  
Three Gorges Reservoir ◽  
Spatiotemporal Distribution ◽  
Three Gorges ◽  
Flood Season ◽  
The Three Gorges ◽  
Upper Yangtze River ◽  
River Reservoir ◽  
The Upper Yangtze River

The river–reservoir transitional zones play an important role in maintaining riverine fish biodiversity and abundance in highly regulated rivers. The Upper Yangtze River, which contains 286 fish species, is experiencing intense hydropower development. However, few studies have been conducted on the spatial distribution of fish in the river–reservoir transitional zones in the Upper Yangtze River, and it is therefore difficult to predict how this development will impact the region. In this study, a 200-kHz split-beam acoustic system in combination with biological samplings was used to investigate the composition and spatiotemporal distribution of the fish in the transition zone of the Three Gorges Reservoir (TGR) in 2017. The biological samplings comprised 7434 individuals from 61 species, 38 genera, 15 families, and 5 orders. The dominant fish species were Rhinogobio cylindricus, Coreius guichenoti, Hemiculter bleekeri, and Pelteobagrus vachelli. Acoustic detection identified the mean target strength (TS) to be −55.6 in May, −57.8 in August, and −55.8 dB in December. Accordingly, the average fish density was 4.96, 6.96, and 4.42 ind/1000 m3. Significant differences were found in the TS and fish density between flood season (August) and non-flood season (May and December). Spatially, fish preferred the meandering sections at 10–20 m deep. A size-dependent vertical distribution pattern was observed, with larger fish in the deeper layers and smaller fish in shallower waters. Lastly, our results suggest that meandering deep channels should be assigned high priority with respect to fish conservation in the Upper Yangtze River.

Fishery Resources, Environment, and Conservation in the Mississippi and Yangtze (Changjiang) River Basins

2016 ◽  
Keyword(s):  
Fish Species ◽  
Yangtze River ◽  
Three Gorges Reservoir ◽  
Management Strategies ◽  
Commercial Fishing ◽  
Three Gorges ◽  
The Three Gorges Reservoir ◽  
The Three Gorges ◽  
Upper Yangtze River ◽  
Sampling Locations

<em>Abstract</em>.—In this paper, we report fish resources in the upper reach of the Yangtze River from 2011 to 2012. The five sampling locations were Yibin, Hejiang, Mudong, Wanzhou, and Zigui. Yibin and Hejiang are the most upstream locations; Mudong is at the upper end of the Three Gorges Reservoir while Wanzhou and Zigui are in the inundated areas of the Three Gorges Reservoir. During our investigations, we collected 56, 94, 93, 67, and 64 fish species, respectively, from these five locations. Among them, 13, 21, 17, 4, and 4 are endemic to the upper Yangtze River. Catch per unit effort calculated with pooled data were 1,221.6–6,433.9 g/(d• boat). Because Yibin and Hejiang are still in the riverine state, endemic species remain. These areas are also in the national protected areas range. We suggest that commercial fishing should be banned in these areas to protect endemic fish species. However, for Wanzhou and Zigui, because they are in the inundated reservoir area, dominance has shifted from riverine to lacustrine species. Fisheries strategies should also be changed to target on different species, employ different fishing gears, and apply different management strategies.

The Eco-Hydrological Demand Research on Coreiusheterodon Reproduction in the Upper Yangtze River Reserve

2014 ◽  
Vol 641-642 ◽  
pp. 226-231 ◽  
Author(s):  
Bing Yu Chen ◽  
Hui Huang Luo ◽  
Qing Rui Yang ◽  
Wei Huang ◽  
Hui Ling Han
Keyword(s):  
Yangtze River ◽  
Nature Reserve ◽  
Fish Habitat ◽  
Main Stream ◽  
Jinsha River ◽  
National Nature Reserve ◽  
Upper Yangtze River ◽  
Downstream Reach ◽  
Set Up ◽  
The Upper Yangtze River

The upper Yangtze river rare and endemic national nature reserve was set up to protect the rare and endemic fish. Affected by the cascade development of the downstream reach of the jinsha river, fish habitat in the national nature reserve have been changed significantly, which will affect the reproduction and growth of the fishes.The Coreius heterodon spawning grounds were located in the Main stream of the natural reserve, andits spawning season needs certain overflowing process to lay eggs. This article used the water level and flow data from 1956 to 2012 in the Zhu Tuo stationto analysis the eco-hydrologicaldemand for Coreiusheterodon breeding. and this result can provide the reference for the ecological operation of cascade reservoirs in the downstreamof jinsha river.

The Influence of Hydrodynamic Conditions on Algal Bloom in the Three Gorges Reservoir Tributaries

2013 ◽  
Vol 295-298 ◽  
pp. 1981-1990 ◽  
Author(s):  
Chao Jun Xiong ◽  
De Fu Liu ◽  
Bing Hui Zheng ◽  
Jia Lei Zhang ◽  
Nian San Hu ◽  
...  
Keyword(s):  
Flow Velocity ◽  
Yangtze River ◽  
Three Gorges Reservoir ◽  
Algal Bloom ◽  
General Situation ◽  
Main Stream ◽  
Three Gorges ◽  
Hydrodynamic Conditions ◽  
The Three Gorges Reservoir ◽  
The Three Gorges

Water level has risen considerably since the impounding of Three-Gorges Reservoir in year 2003 and that might broaden and deepen the Yangtze River and the tributary of Three Gorge, will greatly slowdown the flow velocity to change hydrodynamic conditions. This changes Influence the Water Environment of Yangtze River and the tributary of Three Gorges Reservoir, especially eutrophication and algal bloom of the tributaries in Three Gorges Reservoir in recent years. For studying the course of algal bloom in the tributaries of Three Gorges Reservoir and the comprehensive prevention countermeasures, about the hydrodynamics of Yangtze River main stream and tributary in Three Gorges Reservoir must be carefully researched. In this article, general situation of the algal bloom of the tributaries in Three Gorges Reservoir were presented, and analysed on characteristics and influencing factors of breakout of algal bloom from certain self-conditions changes before and after impoundment of the Three Gorges reservoir, knowing that lower the nutrient input and improve water flow regime and flow velocity behaviors are the main measures of comprehensive prevention countermeasures of algal bloom in the tributaries of Three Gorges Reservoir; This research status of influence mechanism of hydrodynamic conditions on algal bloom and the research tendency of the tributaries’ hydrodynamic conditions on algal bloom in Three Gorges Reservoir were reviewed, which provided certain theory reference for study and prevention countermeasures of algal bloom in the Three Gorges Reservoir tributaries.

Rate and Distribution of Sedimentation in the Three Gorges Reservoir, Upper Yangtze River

2018 ◽  
Vol 144 (8) ◽  
pp. 05018006 ◽  
Author(s):  
Wenjie Li ◽  
Shengfa Yang ◽  
Yi Xiao ◽  
Xuhui Fu ◽  
Jiang Hu ◽  
...  
Keyword(s):  
Yangtze River ◽  
Three Gorges Reservoir ◽  
Three Gorges ◽  
The Three Gorges Reservoir ◽  
The Three Gorges ◽  
Upper Yangtze River
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