Should the Three Gorges Dam be blamed for the extremely low water levels in the middle-lower Yangtze River?

2013 ◽  
Vol 28 (1) ◽  
pp. 150-160 ◽  
Author(s):  
Xijun Lai ◽  
Jiahu Jiang ◽  
Guishan Yang ◽  
X. X. Lu
Keyword(s):  
Yangtze River ◽  
Water Levels ◽  
Three Gorges Dam ◽  
Three Gorges ◽  
The Three Gorges ◽  
Lower Yangtze ◽  
The Three Gorges Dam

scholarly journals The Time Delay of Flow and Sediment in the Middle and Lower Yangtze River and Its Response to the Three Gorges Dam

2018 ◽  
Vol 19 (3) ◽  
pp. 625-638 ◽  
Author(s):  
Yangyang Li ◽  
Yingxin Zhu ◽  
Lei Chen ◽  
Zhenyao Shen
Keyword(s):  
Time Series ◽  
Time Delay ◽  
Yangtze River ◽  
Sediment Concentration ◽  
Three Gorges Dam ◽  
Three Gorges ◽  
River Section ◽  
The Three Gorges ◽  
Lower Yangtze ◽  
The Three Gorges Dam

Abstract As the largest hydropower project in the world, the Three Gorges Dam (TGD) has drawn extensive concern in terms of its impact on downstream areas. In this study, an improved time delay estimation and wavelet analysis were used to investigate the influence of the TGD on the streamflow and sediment in the middle and lower Yangtze River, using time series of the daily discharge and sediment concentration data from three hydrological stations downstream of the dam. The results indicated that all of the time series at the three stations have prominent annual cycles, but the cycle of daily mean sediment concentration was nearly nonexistent after the impoundment of the TGD. Changes in discharge and sediment between the Yichang and the Hankou stations are larger than those between the Hankou and the Datong stations, which is mainly attributed to the streamflows of tributaries and Dongting Lake and the flood diversion area of Jingjiang. The transmission time of discharge for the whole Yichang–Datong river section is approximately 6 days. In addition, the attenuation of discharge from the Yichang station to the Datong station is 20%–30%. In contrast, the transmission of suspended sediment is slower than that of discharge, which takes 7–7.5 days to move from the Yichang station to the Datong station. The attenuation of sediment is approximately 30% in the Yichang–Datong river section and shows a clear increasing trend after 2006, mainly because a large amount of sediment was trapped by the TGD, and the dynamic balance of sediment was disturbed.

Relationship between Waterway Depth and Low-Flow Water Levels in Reaches below the Three Gorges Dam

2019 ◽  
Vol 145 (1) ◽  
pp. 04018032 ◽  
Author(s):  
Yunping Yang ◽  
Mingjin Zhang ◽  
Wanli Liu ◽  
Jianjun Wang ◽  
Xiaoxing Li
Keyword(s):  
Water Levels ◽  
Three Gorges Dam ◽  
Low Flow ◽  
Three Gorges ◽  
The Three Gorges ◽  
The Three Gorges Dam

scholarly journals Response of vegetation to submergence along Jingjiang Reach of the Yangtze River

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0251015
Author(s):  
Guoliang Zhu ◽  
Yitian Li ◽  
Zhaohua Sun ◽  
Shinjiro Kanae
Keyword(s):  
Yangtze River ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
High Elevation ◽  
Three Gorges Dam ◽  
Vegetation Coverage ◽  
Three Gorges ◽  
The Yangtze River ◽  
The Three Gorges ◽  
The Three Gorges Dam

This work explores the changes in vegetation coverage and submergence time of floodplains along the middle and lower reaches of the Yangtze River (i.e., the Jingjiang River) and the relations between them. As the Three Gorges Dam has been operating for more than 10 years, the original vegetative environment has been greatly altered in this region. The two main aspects of these changes were discovered by analyzing year-end image data from remote sensing satellites using a dimidiate pixel model, based on the normalized difference vegetation index, and by calculating water level and topographic data over a distance of 360 km from 2003–2015. Given that the channels had adjusted laterally, thus exhibiting deeper and broader geometries due to the Three Gorges Dam, 11 floodplains were classified into three groups with distinctive features. The evidence shows that, the floodplains with high elevation have formed steady vegetation areas and could hardly be affected by runoff and usually occupied by humans. The low elevation group has not met the minimal threshold of submerging time for vegetation growth, and no plants were observed so far. Based on the facts summed up from the floodplains with variable elevation, days needed to spot vegetation ranges from 70 to 120 days which happened typically near 2006 and between 2008 and 2010, respectively, and a negative correlation was detected between submergence time and vegetation coverage within a certain range. Thus, floods optimized by the Three Gorges Dam have directly influenced plant growth in the floodplains and may also affect our ability to manage certain types of large floods. Our conclusions may provide a basis for establishing flood criteria to manage the floodplain vegetation and evaluating possible increases in resistance caused by high-flow flooding when these floodplains are submerged.

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