scholarly journals Quantitative assessment of water level regime alterations during 1959–2016 caused by Three Gorges Reservoir in the Dongting Lake, China

2020 ◽  
Author(s):  
Hongxiang Wang ◽  
Yongwei Zhu ◽  
Hufei Zha ◽  
Wenxian Guo
Keyword(s):  
Water Level ◽  
Three Gorges Reservoir ◽  
Negative Impact ◽  
Terrestrial Ecosystems ◽  
Dongting Lake ◽  
Water Levels ◽  
Three Gorges ◽  
Hydrologic Alteration ◽  
Lake Ecosystems ◽  
Level Regime

Abstract Water level is considered as the key factor affecting the structure and function of lake ecosystems. The Mann-Kendall technique and range of variability approach were used to quantitatively evaluate the hydrologic alteration due to Three Gorges Reservoir in Dongting Lake. Results indicate the following: (1) The average annual water levels at Chenglingji station showed increasing trends (p < 0.05), while that at Nanzui station showed a decreasing trend (p < 0.05). The turning year occurred in 2003, which reflects the significant effects of the TGR on the water level regime. (2) The highly altered parameters were 1-, 3-, and 7-day minimum water levels both at Chenglingji and Yangliutan, and October both at Nanzui and Yangliutan, with the degree of hydrologic alteration being larger than 80%. However, 1-, 3-, 7-, and 30-day maximum water levels at three stations were relatively small alteration, with the degree of hydrologic alteration being smaller than 41%. (3) The hydrologic alteration degrees at Chenglingji, Nanzui and Yangliutan station were all moderate, with changes of 50, 46 and 49%, respectively. (4) Water level regimes at Dongting Lake were mainly jointly affected by reservoir operation, land utilization change and river channelization. These changes in water level regimes have a negative impact on aquatic and terrestrial ecosystems. This study provides a scientific reference for the protection of lake ecosystems under hydrologic alteration.

Analysis of the Three Gorges Reservoir Operation on the Water Level of Yangtze River during the Non-Flood Season

2013 ◽  
Vol 864-867 ◽  
pp. 2207-2212 ◽  
Author(s):  
Jing Zheng
Keyword(s):  
Water Level ◽  
Yangtze River ◽  
Three Gorges Reservoir ◽  
Water Levels ◽  
Three Gorges ◽  
The Yangtze River ◽  
The Three Gorges Reservoir ◽  
Flood Season ◽  
The Three Gorges ◽  
Downstream Area

In the middle and downstream area of the Yangtze River, low water levels had occurred at post-flood season or before the flood season in recent years, since the trial impoundment of the Three Gorges Reservoir (TGR) in 2008. Based on the analysis of the low water levels, both rating curve of main stations in the middle and lower reaches of the Yangtze River and the operation of TGR in the dry season were analyzed in study to reveal the effects of the impoundment of TGR on water level of downstream areas. The research results show that the water supplement of the TGR could raise the downstream water level, which has positive effect on water supplement and navigation in this area.

Three Gorges Reservoir Water Level Fluctuation Influents on the Stability of the Slope's Analysis

2013 ◽  
Vol 739 ◽  
pp. 283-286 ◽  
Author(s):  
Li Ming Wu ◽  
Zhen Qiang Wang
Keyword(s):  
Finite Element ◽  
Water Level ◽  
Three Gorges Reservoir ◽  
Element Model ◽  
Water Levels ◽  
Three Gorges ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Finite Element Software ◽  
Survey Report

Since the three Gorges reservoir Water storage, reservoir water level have about 30m water levels fluctuation every year, different level will lead to the bank slope infiltration lines rise and fall, and influent on the bank slopes stability. The test according to Manzo reservoir laboratory test data and geological survey report, using the finite element software of ANSYS to establish the finite element model. The model put different water level decline speed, different osmotic coefficient and the different infiltration recharge tension cases to analysis separately,the result shows:1) more greater the reductions speed, more steeper the saturation lines luffing, more adverse the slopes stability;2) more smaller the permeability coefficient, more poor the slopes drainage capacity,more steeper the infiltration line, more poor the slopes stability; 3) seepage lines position higher than no infiltration seepage lines position.

scholarly journals Assessing the Ecological Water Level: The Case of Four Mediterranean Lakes

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2977 ◽  
Author(s):  
Olga Petriki ◽  
Dimitrios Zervas ◽  
Charalampos Doulgeris ◽  
Dimitra Bobori
Keyword(s):  
Water Level ◽  
Water Regime ◽  
Fish Fauna ◽  
Ecological Factors ◽  
Water Levels ◽  
International Standards ◽  
Water Level Fluctuations ◽  
Lake Ecosystems ◽  
Level Regime ◽  
Ecological Water Level

The ecological water regime in lake water bodies refers to the water levels that enable the fulfillment of the ecosystem’s multiple functions. Therefore, assessing the ecological water regime necessitates the consideration of hydrological, economic, social, and ecological factors. The present research is focused on the assessment of the ecological water level of four Mediterranean natural lake ecosystems, considering their morphological and biological features. Initially, suggestions on the ecological water regime of the studied lakes were made based on an analysis of the lakes’ morphometry. Further, the ecological and biological requirements of the present fish fauna and aquatic macrophytic vegetation were considered. For the latter, mapping was conducted by extensive sampling according to international standards, in order to assess macrophyte composition, abundance, and chorology, as well as species sensitivity to water level fluctuations. The above guided the proposals on the optimal water level regime that should be met by each lake regarding the macrophytic and fish communities’ sustainability, also taking into account the unique hydromorphological features of each lake. The differences in the outcoming results revealed that hydromorphological and biological approaches should be combined for assessing lakes’ ecological water regimes.

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