Quantitative assessment of hydrological alteration over multiple periods caused by human activities at the Jingjiang Three Outlets, China

Abstract The Jingjang Three Outlets (JTO) play a major role in the water-sediment transport from the Yangtze River to Dongting Lake. The hydrological regimes at the JTO (Songzi, Taiping, and Ouchi) had been changed due to the Jingjiang Cutoffs (JC), the Gezhou Dam (GD), and the Three Gorges Dam (TGD). Based on hydrological data from 1955 to 2019, the variation trend in annual streamflow was detected using three techniques, and the hydrological alteration was assessed with the Range of Variability Approach. Conclusions are as follows: (1) the inflection points consistent with human activities and the time series were divided into periods of P1 (1955–1971), P2 (1972–1985), P3 (1986–2002), and P4 (2003–2019); (2) human activities made a greater contribution to streamflow change than climate change; (3) the hydrological alteration degree caused by the JC, GD, and TGD projects were 56%, 47%, and 52% at the Songzi outlet; 57%, 41%, and 57% at the Taiping outlet; and 57%, 41%, and 57% at the Ouchi outlet; and (4) the ability of division from the Yangtze River to Dongting Lake is weakening and the hydrological regimes at the JTO are deteriorating due to the JC, GD, and TGD, resulting in negative impacts on the biotic composition, structure, and function of riparian ecosystems. This study provides useful insight for ecosystem protection under hydrological alteration. HIGHLIGHT Quantitative assessment of hydrological alteration over multiple periods. Differentiated the influence of cutoffs projects and dam construction on hydrological alteration. Discussed the negative impacts of hydrological alteration on ecosystems and the countermeasures for future.

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Ecological water demand in the typical polder of Dongting Lake

10.5194/egusphere-egu2020-7057 ◽

2020 ◽

Author(s):

Yi Cai ◽

Lihua Tang ◽

Dazuo Tian ◽

Xiaoyi Xu

Keyword(s):

Water Demand ◽

Human Activities ◽

Yangtze River ◽

Human Impacts ◽

Dongting Lake ◽

The Yangtze River ◽

Ecological Water Demand ◽

Lake Region ◽

The Relationship ◽

Water Ecology

<p>Dongting Lake is the largest lake in the middle reaches of the Yangtze River in China. After the completion of the Three Gorges Project, the relationship between the Yangtze River and Dongting Lake has a significant change&#160;with the decreased diversion ratio. Besides, due to the overexploitation of local human activities, some dry-up reaches appeared in the Dongting Lake&#160;region, especially in the polders&#160;with high strength &#160;human activities. In order to scientifically understand the evolution law of water resources in those protective embankments in lakeside areas, and understand the relationship between human activities and ecosystem stability, the study works&#160;on the ecological water demand that coupled with the ecological capacity of the environment. As a typical polder,&#160;the Yule polder is selected as a case study in the Dongting Lake region. The objective is&#160;to obtain the ecological water demand process which can maintain the requirements of water quantity and quality of water to maintain water ecological needs under the condition of significant human impacts.&#160;Based on the actual situation of vegetation coverage, aquatic organism&#160;growth status and protection goals, and water demand of the industrial and agricultural population, taking the satisfaction degree of ecological water demand as an indicator, healthy of local water ecology is to be evaluated. Combining the hydrological situation of entire Yangtze River basin, the temporal distribution characteristics of ecological water demand in the Yule polder&#160;is analyzed, and also the feasibility of measures such as diverting Yangtze River water to alleviate the fragility of water ecology in the Dongting Lake region&#160;is discussed. These results could&#160;provide experience for solving similar problems in other regions.</p>

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Accelerated human activities affecting the spatial pattern of temperature in the Yangtze River Delta

Quaternary International ◽

10.1016/j.quaint.2010.04.027 ◽

2010 ◽

Vol 226 (1-2) ◽

pp. 112-121 ◽

Cited By ~ 16

Author(s):

Z.Q. Xie ◽

Y. Du ◽

Y. Zeng ◽

M.L. Yan ◽

C.Y. Zhu

Keyword(s):

Spatial Pattern ◽

Human Activities ◽

Yangtze River ◽

Yangtze River Delta ◽

River Delta ◽

The Yangtze River ◽

The Yangtze River Delta

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Lateral migration of fish between China’s second largest freshwater lake (Dongting Lake) and the mainstem of the Yangtze River

Environmental Biology of Fishes ◽

10.1007/s10641-019-00851-0 ◽

2019 ◽

Vol 102 (4) ◽

pp. 527-539

Author(s):

Xiangchao Qin ◽

Zheng Gong ◽

Huanzhang Liu

Keyword(s):

Yangtze River ◽

Dongting Lake ◽

Freshwater Lake ◽

The Yangtze River ◽

Lateral Migration

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Ecological Environment of Wetland Nature Reserve along the Yangtze River in Anqing and Economic Development Policies

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.71-78.2727 ◽

2011 ◽

Vol 71-78 ◽

pp. 2727-2730

Author(s):

Min Yi Huang ◽

Ren Yan Duan ◽

Li Feng Wu ◽

Shan Shan Zhu ◽

Xue Li

Keyword(s):

Yangtze River ◽

Nature Reserve ◽

Academic Community ◽

Ecological Environment ◽

The Yangtze River ◽

Ecological Benefits ◽

Development Policies ◽

Water Conservancy ◽

And Function ◽

Wetland Resources

The wetland possesses very important environmental function and ecological benefits. Study on the Wetland Nature Reserve along the Yangtze River in Anqing has become a focus of academic community for its well nature. The resources and function of wetland along the Yangtze River in Anqing were analyzed and the dangers faced by the wetland from agricultural pollution, water conservancy, unreasonable fishery production, invasive species were discussed. In order to promote sustainable development of wetland resources and environment, the suggestions and policies about the protection for Anqing wetland resources and environment were proposed.

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Dating recent lake sediments from lakes in middle reach of the Yangtze River considering disturbance of human activities

Quaternary International ◽

10.1016/j.quaint.2012.08.1906 ◽

2012 ◽

Vol 279-280 ◽

pp. 543

Author(s):

Weilan Xia

Keyword(s):

Lake Sediments ◽

Human Activities ◽

Yangtze River ◽

The Yangtze River ◽

Middle Reach

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Vegetation history and dynamics in the middle reach of the Yangtze River during the last 1500 years revealed by sedimentary records from Taibai Lake, China

The Holocene ◽

10.1177/0959683612450195 ◽

2012 ◽

Vol 23 (1) ◽

pp. 57-67 ◽

Cited By ~ 9

Author(s):

Xiayun Xiao ◽

Xiangdong Yang ◽

Ji Shen ◽

Sumin Wang ◽

Bin Xue ◽

...

Keyword(s):

Human Activities ◽

Yangtze River ◽

Detrended Correspondence Analysis ◽

Transitional Period ◽

Vegetation Changes ◽

The Yangtze River ◽

Mixed Conifer ◽

Middle Reach ◽

Evergreen Broadleaved Forest ◽

Pollen Types

Pollen and charcoal records of a 150 cm long lake sediment core from Taibai Lake in the middle reach of the Yangtze River reveal seven major changes in regional vegetation over the last 1500 years. During the period c. ad 480–710, evergreen broadleaved forest dominated by Castanopsis/Lithocarpus and evergreen oaks occurred in the Taibai Lake catchment. From c. ad 710 to 1050, the vegetation shifted to a mixed conifer and broadleaved forest, with Pinus expanding at the expense of Castanopsis/Lithocarpus. Between c. ad 1050 and 1320, evergreen broadleaved forest reoccupied the studied area. From c. ad 1320 to 1650, the area of primary forest decreased markedly with synchronous reduction in broadleaved trees and Pinus. Between c. ad 1650 and 1740, the biomass declined rapidly, while secondary Pinus forest began to expand. During c. ad 1740–1950, forest extent increased slightly compared with the previous stage, but the landscape was still secondary forest with the minimum proportion of broadleaved trees. After c. ad 1950, the biomass in the surrounding area was very low, with vegetation types similar to that at present (secondary Pinus forest and mixed conifer and broadleaved forest). A detrended correspondence analysis (DCA) with 125 samples and 34 main pollen types is used to separate human and climatic impacts on vegetation. Then, the pollen assemblage, DCA, charcoal record, and magnetic susceptibility are combined to discuss the key factors inducing these vegetation changes. The vegetation changes were mainly controlled by the climatic changes, with the weak impacts of human activities before c. ad 1320. Since then, the intensity of human influences on vegetation increased gradually, entering a transitional period of main controlling factors of vegetation changes from nature to human activities. After c. ad 1740, the vegetation changes were chiefly controlled by human activities, and the climatic signal was weak.

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