scholarly journals Climate-induced hydrologic change in the source region of the Yellow River: a new assessment including varying permafrost

2018 ◽  
Author(s):  
Pan Wu ◽  
Sihai Liang ◽  
Xu-Sheng Wang ◽  
Yuqing Feng ◽  
Jeffrey M. McKenzie
Keyword(s):  
Climate Change ◽  
Human Activities ◽  
Yellow River ◽  
Source Region ◽  
The Yellow River ◽  
Observation Data ◽  
Total Change ◽  
Hydrologic Change ◽  
Long Term Observation ◽  
The Impact

Abstract. The source region of the Yellow River (SRYR) provides 35 % of the rivers annual discharge but is very sensitive to the climate change. The change in discharge from the SRYR has been attributed to both climatic and anthropogenic forces, and previous estimates of the impact of human activities on the change in discharge have been higher than 50 % of the total change. Considering the very low population density and limited land use change, this result is potentially inconsistent. Our study modifies the traditional Budyko separating approach to identify and quantify the climatic causes in discharge changes. Application of this new approach to the SRYR now highlights the role of the degrading permafrost, based on long-term observation data of the maximum frozen depth (MFD). Our results show that over the past half-century, the change in discharge in the SRYR was primarily controlled by climate change rather than local human activities. Increasing air temperature is generally a negative force on discharge whereas it also causes permafrost to degrade – a positive factor on discharge generation. Such conflicting effects enhance the uncertainty in assessments of the hydrological response to climate change in the SRYR.

scholarly journals Quantitative analysis on sensitive factors of runoff change in Fenhe watershed based on integration approach

2018 ◽  
Vol 379 ◽  
pp. 371-380 ◽  
Author(s):  
Deng Wang ◽  
Shengqi Jian ◽  
Zening Wu ◽  
Zhaoxi Zhang ◽  
Caihong Hu
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
Human Activities ◽  
Yellow River ◽  
Shanxi Province ◽  
The Yellow River ◽  
Groundwater Exploitation ◽  
Total Reduction ◽  
Runoff Change ◽  
The Impact

Abstract. The runoff of the Fenhe River flowed into the Yellow River (RRY) is reducing significantly due to the influence of climate change and human activities. It is generating bad situation of shortage of water resources and led to the deterioration of ecological environment of Shanxi Province. At the same time, the reduction in RRY causes the runoff reduction in Yellow River and exacerbated the water resources shortage of the middle area of the Yellow River. Therefore, it is important to alleviate water shortage and develop the soil and water conservation measurements and regional water policy by analyzing the influence of human activities and climate change on the RRY. The existing study quantified the reduction in amount of RRY which caused by human activities and climate change using statistical methods and watershed hydrological model. The main results of the study were as follow: Using hydrological variation diagnosis system, the variation characteristics of long time series of measured annual runoff were analyzed in Hejin station that is the Fenhe River control station. The results showed that the runoff of Fenhe River run into Yellow River declined year by year, in 1971, fell the most obviously. The impact of LUCC on runoff was calculated using the method of area ratio in the Fenhe River basin. Human activities were major factor in the reduction of RRY than the climate change, contributed 83.09 % of the total reduction in RRY, Groundwater exploitation gave the greatest contribution to the decrease in RRY in the scope of several kinds of human activity (30.09 %), followed by coal mining (26.03 %), climate changed contributed 19.17 % of the total reduction of RRY, and the decrease of precipitation contributed 20.81 %. But the variation of air temperature and wind speed would result in the increase of the amount of RRY.

scholarly journals SWAT-Based Runoff Simulation and Runoff Responses to Climate Change in the Headwaters of the Yellow River, China

Atmosphere ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 509
Author(s):  
Jingwen Wu ◽  
Haiyan Zheng ◽  
Yang Xi
Keyword(s):  
Climate Change ◽  
Assessment Tool ◽  
Water Cycle ◽  
Yellow River ◽  
Annual Runoff ◽  
The Yellow River ◽  
Runoff Simulation ◽  
Alpine Regions ◽  
Slight Upward Trend ◽  
The Impact

Runoff in snowy alpine regions is sensitive to climate change in the context of global warming. Exploring the impact of climate change on the runoff in these regions is critical to understand the dynamics of the water cycle and for the improvement of water resources management. In this study, we analyzed the long-term variations in annual runoff in the headwaters region of the Yellow River (HRYR) (a typical snowy mountain region) during the period of 1956–2012. The Soil and Water Assessment Tool (SWAT) with different elevation bands was employed to assess the performance of monthly runoff simulations, and then to evaluate the impacts of climate change on runoff. The results show that the observed runoff for the hydrological stations at lower relative elevations (i.e., Maqu and Tangnaihai stations) had a downward trend, with rates of 1.91 and 1.55 mm/10 years, while a slight upward trend with a rate of 0.26 mm/10 years was observed for the hydrological station at higher elevation (i.e., Huangheyan station). We also found that the inclusion of five elevation bands could lead to more accurate runoff estimates as compared to simulation without elevation bands at monthly time steps. In addition, the dominant cause of the runoff decline across the whole HRYR was precipitation (which explained 64.2% of the decrease), rather than temperature (25.93%).

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.

Hydrological Cycles Change in the Yellow River Basin during the Last Half of the Twentieth Century

2008 ◽  
Vol 21 (8) ◽  
pp. 1790-1806 ◽  
Author(s):  
Qiuhong Tang ◽  
Taikan Oki ◽  
Shinjiro Kanae ◽  
Heping Hu
Keyword(s):  
Climate Change ◽  
River Basin ◽  
Human Activities ◽  
River Discharge ◽  
Yellow River ◽  
Yellow River Basin ◽  
The Yellow River ◽  
Linear Component ◽  
Annual Streamflow ◽  
The Yellow River Basin

Abstract A distributed biosphere hydrological (DBH) model system was used to explore the internal relations among the climate system, human society, and the hydrological system in the Yellow River basin, and to interpret possible mechanisms for observed changes in Yellow River streamflow from 1960 to 2000. Several scenarios were evaluated to elucidate the hydrological response to climate system, land cover, and irrigation. The results show that climate change is the dominant cause of annual streamflow changes in the upper and middle reaches, but human activities dominate annual streamflow changes in the lower reaches of the Yellow River basin. The annual river discharge at the mouth is affected by climate change and by human activities in nearly equal proportion. The linear component of climate change contributes to the observed annual streamflow decrease, but changes in the climate temporal pattern have a larger impact on annual river discharge than does the linear component of climate change. Low flow is more significantly affected by irrigation withdrawals than by climate change. Reservoirs induce more diversions for irrigation, while at the same time the results demonstrate that the reservoirs may help to maintain environmental flows and counter what otherwise would be more serious reductions in low flows.

Sign in / Sign up

Export Citation Format

Share Document