scholarly journals Field Investigation on River Hydrochemical Characteristics and Larval and Juvenile Fish in the Source Region of the Yangtze River

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1342 ◽  
Author(s):  
Zhao ◽  
Li ◽  
Lin ◽  
Guo ◽  
Zhao ◽  
...  
Keyword(s):  
Metal Ions ◽  
Water Temperature ◽  
Yangtze River ◽  
Positive Response ◽  
Juvenile Fish ◽  
Source Region ◽  
Class I ◽  
Tibet Plateau ◽  
The Yangtze River ◽  
Hydrochemical Characteristics

The source region of the Yangtze River (SRYR) is located in the Qinghai-Tibet Plateau, where the climatic conditions and alpine-cold natural conditions are harsh. Field investigations of the hydrochemical characteristics and larva and juvenile fish in rivers of the SRYR were carried out in July 2018 with the aim of obtaining further information on the unique ecological environment status of this plateau area. The results of the present research indicated that majority of the river water quality parameters in the SRYR were in the range of class I to class II, according to the classification of the environmental quality standard for surface water (GB3838-2002) in China. Among 12 kinds of metal ions, the concentrations of four major ions occurred in the following order: Ca > Na > Mg > K. The concentrations of eight heavy metal ions (Fe, Mn, Cu, Zn, Pb, Cd, Cr and As) were all within the class I water range based on GB3838-2002. A total of three species of larval and juvenile fish, i.e., Triplophysa stenura (T. stenura), Schizopygopsis microcephalus Herzenstein (S. microcephalus) and Triplophysa bleekeri (T. bleekeri), were collected from 11 sampling sites. It was found that T. stenura covered the widest distribution range and was the most abundant. The results of principal component analysis and canonical correspondence analysis demonstrated that the distribution of S. microcephalus exhibited a positive response to water temperature, a positive response to K and a negative correlation with water temperature were demonstrated in the distribution of T. stenura. T. bleekeri distribution had a positive response to Cu, but negative responses to total phosphorus and total dissolved solid.

Monitoring permafrost changes in the Yangtze River source region of the Qinghai-Tibetan Plateau using differential SAR interferometry

2020 ◽  
Author(s):  
Lingxiao Wang ◽  
Lin Zhao ◽  
Huayun Zhou ◽  
Shibo Liu ◽  
Xiaodong Huang ◽  
...  
Keyword(s):  
Active Layer ◽  
Yangtze River ◽  
Ground Deformation ◽  
Source Region ◽  
Deformation Monitoring ◽  
Tibet Plateau ◽  
Permafrost Degradation ◽  
The Yangtze River ◽  
Ground Ice

<p>Qinghai-Tibet Plateau (QTP) has the largest high-altitude permafrost zone in the middle and low latitudes. Substantial hydrologic changes have been observed in the Yangtze River source region and adjacent areas in the early 21st century. Permafrost on the QTP has undergone degradation under global warming. The ground leveling observation site near Tangula (33°04′N, 91°56′E) located in the degraded alpine meadow indicates that the ground has subsided 50mm since 2011. The contribution of permafrost degradation and loss of ground ice to the hydrologic changes is however still lacking. This study monitors the permafrost changes by applying the Small BAseline Subset InSAR (SBAS-InSAR) technique using C-band Sentinel-1 datasets during 2014-2019. The ground deformation over permafrost terrain is derived in spatial and temporal scale, which reflects the seasonal freeze-thaw cycle in the active layer and long-term thawing of ground ice beneath the active layer. Results show the seasonal thaw displacement exhibits a strong correlation with surficial geology contacts. The ground leveling data is used to validate the ground deformation monitoring results. Then, the ground deformation characteristics are analyzed against the landscape units. Last, the long-term inter-annual displacement value is used to estimate the water equivalent of ground ice melting.</p>

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 The larvae and juvenile fish resources of the four major Chinese carps at Anqing section in the lower reaches of the Yangtze River from 2016 to 2018

2020 ◽  
Vol 32 (4) ◽  
pp. 1116-1125
Author(s):  
DING Longqiang ◽  
◽  
HE Xiaohui ◽  
LI Xinfeng ◽  
FANG Di'an ◽  
...  
Keyword(s):  
Yangtze River ◽  
Juvenile Fish ◽  
The Yangtze River ◽  
Fish Resources ◽  
Chinese Carps

scholarly journals Timing and causes of the distribution pattern of Oncomelania hupensis estimated by molecular and geologic data

2018 ◽  
Author(s):  
Wen-bin Ji ◽  
Shu-xin Xu ◽  
Jun Bai ◽  
Ying-yi Cui ◽  
Xian-min Zhou ◽  
...  
Keyword(s):  
Distribution Pattern ◽  
Schistosoma Japonicum ◽  
Yangtze River ◽  
Molecular Data ◽  
The Philippines ◽  
Tibet Plateau ◽  
Snail Species ◽  
The Yangtze River ◽  
Oncomelania Hupensis ◽  
Distribution Ranges

Abstract:As the only intermediate host of Schistosoma japonicum, Oncomelania hupensis plays an irreplaceable role in the prevalence of schistosomiasis japonica. Several living subspecies of Oncomelania hupensis are found in Asia, especially in China, Japan,the Philippines, and Sulawesi of Indonesia. The existing geographical distribution pattern of O. hupensis has been influenced by geological events. This study used existing mitochondrial gene data for O. hupensis in the GenBank database and the molecular clock method to estimate the divergence time of each subspecies of O. hupensis. For the first time, the timing and causes of the distribution pattern of the different O. hupensis subspecies were studied by combining molecular data with data on geologic events. The results showed that the uplift and isolation of the Qinghai-Tibet Plateau caused Oncomelania hupensis robertsoni to differentiate 4.76 Ma(Million anniversary), while Oncomelania hupensis guangxiensis was affected by the third Himalayan orogenic movement, differentiating 1.10 Ma. Oncomelania hupensis nosophora was influenced by the formation of the Yonaguni Strait and diverged 1.43 Ma. Influenced by ice ages and interglacial periods, Oncomelania hupensis tangi and Oncomelania hupensis formosana diverged 0.57 Ma. The link of the ancient Yangtze River promoted the spread of O. hupensis to the middle and lower reaches of the Yangtze River, and the developed water network facilitated gene exchange among Oncomelania hupensis hupensis in the area. Eventually, 0.62 Ma, O. h. hupensis differentiated.Author summaryPhylogenetic analysis of Pomatiopsidae species showed that Oncomelania was isolated from other genera and clustered independently in phylogenetic trees. Further analysis of the species Oncomelania hupensis and its subspecies was performed. The snail species O. hupensis has multiple subspecies that exhibit certain differences. These subspecies are distributed across Asia, from China’s Yunnan Province in the west to Japan in the east and south to the Philippines and Indonesia. In addition, the subspecies are widespread in the middle and lower reaches of the Yangtze River in China, and the distribution ranges of the different subspecies do not overlap. The formation of this distribution pattern of each subspecies of O. hupensis has a profound impact on the prevalence of Schistosoma japonicum. Therefore, the authors analyzed molecular data and geological historical events to investigate the timing and causes of the distribution pattern of each subspecies of O. hupensis.

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.

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