Ecological water requirements for the source region of China's Yangtze River under a range of ecological management objectives

2012 ◽  
Vol 37 (3) ◽  
pp. 236-252 ◽  
Author(s):  
Tao Sun ◽  
Zhifeng Yang ◽  
Zhenyao Shen ◽  
Rui Zhao
Keyword(s):  
Yangtze River ◽  
Source Region ◽  
Ecological Management ◽  
Water Requirements ◽  
Management Objectives ◽  
Ecological Water Requirements

Impact of the Three Gorges reservoir operation on downstream ecological water requirements

2012 ◽  
Vol 43 (1-2) ◽  
pp. 48-53 ◽  
Author(s):  
Qiongfang Li ◽  
Meixiu Yu ◽  
Jianhua Zhao ◽  
Tao Cai ◽  
Guobin Lu ◽  
...  
Keyword(s):  
Flow Regime ◽  
Reservoir Operation ◽  
Yangtze River ◽  
Three Gorges Reservoir ◽  
Three Gorges ◽  
The Yangtze River ◽  
Water Requirements ◽  
The Three Gorges Reservoir ◽  
The Three Gorges ◽  
Ecological Water Requirements

With population increase and economic growth, the flow regime of the Yangtze River has been altered to some extent by human activities, particularly dam construction. Dam-induced alterations in the flow regime of the Yangtze River will unavoidably influence water allocation among different water users and instream ecological water requirements may not be guaranteed during some months, particularly during phases of reservoir storing water. To assess the impacts of the Three Gorges reservoir operation on the downstream minimum instream ecological water requirements, this paper selected the Three Gorges reservoir and Yichang hydrological station below the reservoir as case study sites. On the basis of long-term time series of daily discharge data, the reservoir outflow was simulated under two water storing schemes and the degree to which the downstream minimum ecological flow was satisfied was computed. The results of this paper could provide references for the integrated management of the Yangtze River water resources and the assessment of dam-induced impacts on the Yangtze River ecosystem health.

scholarly journals Effects of climatic factors on the net primary productivity in the source region of Yangtze River, China

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhe Yuan ◽  
Yongqiang Wang ◽  
Jijun Xu ◽  
Zhiguang Wu
Keyword(s):  
Climate Change ◽  
Primary Productivity ◽  
Yangtze River ◽  
Net Primary Productivity ◽  
Climatic Factors ◽  
Source Region ◽  
Primary Reason ◽  
Vegetation Types ◽  
Temperature And Precipitation ◽  
Increasing Trend

AbstractThe ecosystem of the Source Region of Yangtze River (SRYR) is highly susceptible to climate change. In this study, the spatial–temporal variation of NPP from 2000 to 2014 was analyzed, using outputs of Carnegie–Ames–Stanford Approach model. Then the correlation characteristics of NPP and climatic factors were evaluated. The results indicate that: (1) The average NPP in the SRYR is 100.0 gC/m2 from 2000 to 2014, and it shows an increasing trend from northwest to southeast. The responses of NPP to altitude varied among the regions with the altitude below 3500 m, between 3500 to 4500 m and above 4500 m, which could be attributed to the altitude associated variations of climatic factors and vegetation types; (2) The total NPP of SRYR increased by 0.18 TgC per year in the context of the warmer and wetter climate during 2000–2014. The NPP was significantly and positively correlated with annual temperature and precipitation at interannual time scales. Temperature in February, March, May and September make greater contribution to NPP than that in other months. And precipitation in July played a more crucial role in influencing NPP than that in other months; (3) Climatic factors caused the NPP to increase in most of the SRYR. Impacts of human activities were concentrated mainly in downstream region and is the primary reason for declines in NPP.

scholarly journals Temperature Change and Its Elevation Dependency in the Source Region of the Yangtze River and Yellow River

2014 ◽  
Vol 6 (2) ◽  
pp. 124 ◽  
Author(s):  
Chongyi E ◽  
Hongchang Hu ◽  
Hong Xie ◽  
Yongjuan Sun
Keyword(s):  
Temperature Change ◽  
Minimum Temperature ◽  
Yangtze River ◽  
Yellow River ◽  
Source Region ◽  
Maximum Temperature ◽  
Climatic Data ◽  
The Yangtze River ◽  
Extreme Minimum Temperature ◽  
The Mean

The study of temperature change and its elevation dependency in the source region of the Yangtze River and Yellow River have been insufficient owing to the lack of adequate observation stations and long-term climatic data. In this study five temperature indices of 32 stations from 1961 to 2007 in and near the source region are used. The 32 stations all have experienced significant warming; the warming amplitudes are higher than the mean warming amplitude of the Qinghai-Tibetan plateau. The warming amplitudes and the numbers of stations showing significant warming trends in mean minimum temperature and extreme minimum temperature are higher than that of the mean maximum temperature and extreme maximum temperature. The elevation dependency of climatic warming and the amount of significant warming stations are not obvious; the influence of human activity and urbanization may be higher. The warming amplitudes of 26 stations above 3000 m tend to be uniform, and there is no significant law at 6 stations below 3000 m. On the contrary, the ratio of stations showing significant warming in minimum temperature above 4000 m is far less than that of the stations below 4000 m.

scholarly journals Impact of the Westerly Jet on Rainfall/Runoff in the Source Region of the Yangtze River during the Flood Season

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Xin Lai ◽  
Yuanfa Gong ◽  
Sixian Cen ◽  
Hui Tian ◽  
Heng Zhang
Keyword(s):  
Water Vapor ◽  
Coastal Zone ◽  
Yangtze River ◽  
Source Region ◽  
Observation Data ◽  
The Yangtze River ◽  
Antecedent Rainfall ◽  
Flood Season ◽  
Westerly Jet ◽  
The Impact

Based on runoff data collected at the Zhimenda station, reanalysis data from the National Centers of Environmental Prediction/National Centers of Atmospheric Research (NCEP/NCAR), and observation data from ground stations in China, this study analyzes the characteristics of changes in runoff in the source region of the Yangtze River (SRYR) during the flood season (from July to September), the relationship between runoff and antecedent rainfall, and the impact of the westerly jet (WJ) on rainfall in the coastal zone of the SRYR. The results show the following. The runoff in the SRYR displays a significant interannual and interdecadal variability. The runoff in the SRYR during the flood season is most closely related to 15-day (June 16 to September 15) antecedent rainfall in the coastal zone of the SRYR. In turn, the antecedent rainfall in the coastal zone of the SRYR is mainly affected by the intensity of the simultaneous WJ over a key region (55–85°E, 45–55°N). When the intensity of the WJ over the key region is greater (less) than normal, the jet position moves northward (southward), and the easterly (westerly) wind anomalies over the region to the west of the SRYR become unfavorable (favorable) to the transport of water vapor from high-latitude regions to the SRYR. In addition, the southerly wind over the equatorial region cannot (can) easily advance northward, which is unfavorable (favorable) to the northward transport of water vapor from the low-latitude ocean. Hence, these conditions result in a decrease (increase) in the water vapor content in the SRYR. Furthermore, the convergence (divergence) anomalies in the upper level and the divergence (convergence) anomalies in the lower level result in the descending (ascending) motion over the SRYR. These factors decrease (increase) the rainfall, thereby decreasing (increasing) the runoff in the SRYR during the flood season.

scholarly journals Contribution of glacial melt to river runoff as determined by stable isotopes at the source region of the Yangtze River, China

2015 ◽  
Vol 47 (2) ◽  
pp. 442-453 ◽  
Author(s):  
Zhaofei Liu ◽  
Zhijun Yao ◽  
Rui Wang
Keyword(s):  
Yangtze River ◽  
Meteoric Water ◽  
Stream Water ◽  
Source Region ◽  
Upstream Region ◽  
The Yangtze River ◽  
Hydrograph Separation ◽  
Water Line ◽  
Total Runoff ◽  
Meteoric Water Line

The primary objective of this study was to quantify the contribution of glacial melt to total runoff in the Gaerqu River catchment, which is located in the source region of the Yangtze River, China. The isotope hydrograph separation method was used to separate glacier melt runoff from total runoff in the catchment. The degree-day method was used to investigate temporal variations in glacial melt runoff. The results showed that the contribution of glacial melt runoff to total runoff was 15.0%. The uncertainty of the separation was ± 3.7% at the confidence level of 95%. Glacial melt runoff was mainly generated in June, July, and August. The runoff coefficient was 0.23 for the catchment. Precipitation-induced runoff constituted 19.9% of the total precipitation, meaning that precipitation loss was >80% across the study period (a hydrological year). The Local Meteoric Water Line (LMWL) of the catchment was fitted as δ2H = 7.75 δ18O + 5.93. This line has a smaller slope and intercept than the Global Meteoric Water Line. The regression-lines for the δ18O and δ2H values of stream water indicated that evaporation was greater over the entire catchment than it was for the upstream region alone.

Runoff dominated by supra-permafrost water in the source region of the Yangtze river using environmental isotopes

2020 ◽  
Vol 582 ◽  
pp. 124506 ◽  
Author(s):  
Zongxing Li ◽  
Zongjie Li ◽  
Qi Feng ◽  
Baijuan Zhang ◽  
Juan Gui ◽  
...  
Keyword(s):  
Yangtze River ◽  
Source Region ◽  
Environmental Isotopes ◽  
The Yangtze River
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