scholarly journals High Riverine CO<sub>2</sub> Outgassing affected by Land Cover Types in the Yellow River Source Region

2018 ◽  
Author(s):  
Mingyang Tian ◽  
Xiankun Yang ◽  
Lishan Ran ◽  
Yuanrong Su ◽  
Lingyu Li ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Co2 Emissions ◽  
Yellow River ◽  
Source Region ◽  
Environmental Parameters ◽  
Terrestrial Ecosystems ◽  
Temporal Variations ◽  
The Yellow River ◽  
Co2 Efflux ◽  
Yellow River Source

Abstract. Rivers connect the land and the oceans, acting as both active pipes and containers transporting carbon and other substances from terrestrial ecosystems to aquatic ecosystems. Meanwhile, rivers can release huge amounts of CO2 to the atmosphere. However, estimates of global riverine CO2 emissions remain greatly uncertain owing to the absence of a comprehensive spatially and temporally CO2 emissions measurement, especially in river source regions. In this study, riverine partial pressure of CO2 (pCO2) and CO2 efflux (FCO2) in the Yellow River source region under different landcover types, including glaciers, permafrost, wetlands, and grasslands, were investigated in April, June, August, and October 2016. The relevant chemical parameters and environmental parameters, including pH, dissolved oxygen (DO), and dissolved organic carbon (DOC), were analyzed to explore the main control factors of riverine pCO2 and FCO2. The results showed that the rivers in the Yellow River source region were a net CO2 source, with the pCO2 ranging from 181 to 2441 μatm and the FCO2 from −221 to 6892 g C m−2 yr−1. Both the pCO2 and FCO2 showed strong spatial and temporal variations. The average FCO2 in August was higher than that in other months, with the lowest in October. In alpine climates, low temperature conditions played a crucial role in limiting biological activity and reducing CO2 emissions. The lowest FCO2 values (−221 g C m−2 yr−1) were observed in the glacier and permafrost regions. By integrating seasonal changes of water surface area, the total CO2 efflux was estimated at 0.37 ± 0.49 Tg C yr−1, which is significantly higher than previous studies. Although it is still a small proportion of CO2 emissions compared with the whole Yellow River Basin, but there is a huge carbon emissions potential. Since the permafrost in the source region of the Yellow River is rich in large amounts of ice and organic carbon, the continuously increasing temperature due to global warming will accelerate not only the mobilization of organic carbon in permafrost, but also the degradation of organic carbon by soil microorganisms. As a consequence, huge amounts of CO2 release from soils and rivers is anticipated.

scholarly journals Impact of Land Cover Types on Riverine CO2 Outgassing in the Yellow River Source Region

Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2243
Author(s):  
Mingyang Tian ◽  
Xiankun Yang ◽  
Lishan Ran ◽  
Yuanrong Su ◽  
Lingyu Li ◽  
...  
Keyword(s):  
Climate Change ◽  
Land Cover ◽  
Yellow River ◽  
Stream Water ◽  
Source Region ◽  
The Yellow River ◽  
Co2 Efflux ◽  
Land Cover Types ◽  
Yellow River Source ◽  
Alpine Rivers

Under the context of climate change, studying CO2 emissions in alpine rivers is important because of the large carbon storage in these terrestrial ecosystems. In this study, riverine partial pressure of CO2 (pCO2) and CO2 emission flux (FCO2) in the Yellow River source region (YRSR) under different landcover types, including glaciers, permafrost, peatlands, and grasslands, were systematically investigated in April, June, August, and October 2016. Relevant chemical and environmental parameters were analyzed to explore the primary controlling factors. The results showed that most of the rivers in the YRSR were net CO2 source, with the pCO2 ranging from 181 to 2441 μatm and the FCO2 ranging from −50 to 1574 mmol m−2 d−1. Both pCO2 and FCO2 showed strong spatial and temporal variations. The highest average FCO2 was observed in August, while the lowest average was observed in June. Spatially, the lowest FCO2 were observed in the permafrost regions while the highest FCO2 were observed in peatland. By integrating seasonal changes of the water surface area, total CO2 efflux was estimated to be 0.30 Tg C year−1. This indicates that the YRSR was a net carbon source for the atmosphere, which contradicts previous studies that conclude the YRSR as a carbon sink. More frequent measurements of CO2 fluxes, particularly through several diel cycles, are necessary to confirm this conclusion. Furthermore, our study suggested that the riverine dissolved organic carbon (DOC) in permafrost (5.0 ± 2.4 mg L−1) is possibly derived from old carbon released from permafrost melting, which is equivalent to that in peatland regions (5.1 ± 3.7 mg L−1). The degradation of DOC may have played an important role in supporting riverine CO2, especially in permafrost and glacier-covered regions. The percent coverage of corresponding land cover types is a good indicator for estimating riverine pCO2 in the YRSR. In view of the extensive distribution of alpine rivers in the world and their sensitivity to climate change, future studies on dynamics of stream water pCO2 and CO2 outgassing are strongly needed to better understand the global carbon cycle.

scholarly journals Research on valuation of water system in source region of the yellow river based on emergy theory

2018 ◽  
Vol 246 ◽  
pp. 01089
Author(s):  
Yongqiang Wang ◽  
Zhiming Liu ◽  
Zhe Yuan ◽  
Jijun Xu ◽  
Jin Chen
Keyword(s):  
Surface Water ◽  
Water Resources ◽  
Yellow River ◽  
Source Region ◽  
Source Area ◽  
The Yellow River ◽  
Energy Value ◽  
Surface Water Resources ◽  
Yellow River Source ◽  
Value Of Water

Taking the source region of the Yellow River as an example, this paper first introduces the theory of energy value and its basic steps. Then combined with the Yellow River source area, the variation characteristics of precipitation and surface water resources from 1961 to 2011 in the Yellow River source area were analyzed, and both of them showed a trend of decreasing year by year. On this basis, using the theory of energy value, combined with relevant parameters, taking 2011 year as an example, further analyses the chemical energy and solar energy of water resources in the Yellow River source area, and gives the value of surface water resources. The value of water resources per unit is 1.59 yuan/m3. For the Yellow River source area, the overall value of water resources for the whole basin in 2011 is 33.55 billion yuan. It can provide a reference for the analysis of the value of surface water resources in the Yellow River Basin.

Impacts of snow disaster on meat production and adaptation: an empirical analysis in the yellow river source region

2015 ◽  
Vol 11 (2) ◽  
pp. 249-260 ◽  
Author(s):  
Yi-ping Fang ◽  
Chen Zhao ◽  
Yong-jian Ding ◽  
Da-he Qin ◽  
Jia-li Huang
Keyword(s):  
Empirical Analysis ◽  
Yellow River ◽  
Source Region ◽  
The Yellow River ◽  
Meat Production ◽  
Yellow River Source

scholarly journals Impacts of climate warming on the frozen ground and eco-hydrology in the Yellow River source region, China

2017 ◽  
Vol 605-606 ◽  
pp. 830-841 ◽  
Author(s):  
Yue Qin ◽  
Dawen Yang ◽  
Bing Gao ◽  
Taihua Wang ◽  
Jinsong Chen ◽  
...  
Keyword(s):  
Climate Warming ◽  
Yellow River ◽  
Source Region ◽  
The Yellow River ◽  
Frozen Ground ◽  
Yellow River Source

scholarly journals Seasonal Variations in Dissolved Organic Carbon in the Source Region of the Yellow River on the Tibetan Plateau

Water ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 2901
Author(s):  
Xiaoni You ◽  
Xiangying Li
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Yellow River ◽  
Source Region ◽  
Precipitation Amount ◽  
Transport Processes ◽  
The Yellow River ◽  
Deposition Flux ◽  
The Tibetan Plateau ◽  
Permafrost Degradation

Rivers as the link between terrestrial ecosystems and oceans have been demonstrated to transport a large amount of dissolved organic carbon (DOC) to downstream ecosystems. In the source region of the Yellow River (SRYR), climate warming has resulted in the rapid retreat of glaciers and permafrost, which has raised discussion on whether DOC production will increase significantly. Here, we present three-year data of DOC concentrations in river water and precipitation, explore the deposition and transport processes of DOC from SRYR. Results show that annual mean concentrations of riverine DOC ranged from 2.03 to 2.34 mg/L, with an average of 2.21 mg/L. Its seasonal variation is characterized by the highest concentration in spring and summer (2.65 mg/L and 2.62 mg/L, respectively), followed by autumn (1.95 mg/L), and the lowest in winter (1.44 mg/L), which is closely related to changes in river runoff under the influence of precipitation and temperature. The average concentration of DOC in precipitation (2.18 mg/L) is comparable with riverine DOC, while the value is inversely related to precipitation amount and is considered to be the result of precipitation dilution. DOC deposition flux in precipitation that is affected by both precipitation amount and DOC concentration roughly was 86,080, 105,804, and 73,072 tons/yr from 2013 to 2015, respectively. DOC flux delivered by the river ranged from 24,629 to 37,539 tons/yr and was dominated by river discharge. Although permafrost degradation in SRYR is increasing, DOC yield is not as significant as previously assumed and is much less than other large rivers in the world.

scholarly journals Expected changes in future temperature extremes and their elevation dependency over the Yellow River source region

2013 ◽  
Vol 17 (7) ◽  
pp. 2501-2514 ◽  
Author(s):  
Y. Hu ◽  
S. Maskey ◽  
S. Uhlenbrook
Keyword(s):  
Interannual Variability ◽  
21St Century ◽  
Yellow River ◽  
Source Region ◽  
Extreme Temperature ◽  
The Yellow River ◽  
Hot Days ◽  
Yellow River Source ◽  
Temperature Indices ◽  
Ipcc Sres

Abstract. Using the Statistical DownScaling Model (SDSM) and the outputs from two global climate models, we investigate possible changes in mean and extreme temperature indices and their elevation dependency over the Yellow River source region for the two future periods 2046–2065 and 2081–2100 under the IPCC SRES A2, A1B and B1 emission scenarios. Changes in interannual variability of mean and extreme temperature indices are also analyzed. The validation results show that SDSM performs better in reproducing the maximum temperature-related indices than the minimum temperature-related indices. The projections show that by the middle and end of the 21st century all parts of the study region may experience increases in both mean and extreme temperature in all seasons, along with an increase in the frequency of hot days and warm nights and with a decrease in frost days. By the end of the 21st century, interannual variability increases in all seasons for the frequency of hot days and warm nights and in spring for frost days while it decreases for frost days in summer. Autumn demonstrates pronounced elevation-dependent changes in which around six out of eight indices show significant increasing changes with elevation.

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