scholarly journals Hydrological connectivity from glaciers to rivers in the Qinghai-Tibet Plateau: roles of suprapermafrost and subpermafrost groundwater

2017 ◽  
Author(s):  
Rui Ma ◽  
Ziyong Sun ◽  
Yalu Hu ◽  
Qixing Chang ◽  
Shuo Wang ◽  
...  
Keyword(s):  
Groundwater Flow ◽  
Stream Flow ◽  
Cold Season ◽  
Tibet Plateau ◽  
High Mountain ◽  
High Mountains ◽  
Piedmont Plain ◽  
Quaternary Aquifer ◽  
Water Conduction ◽  
Qinghai Tibet Plateau

Abstract. The roles of subsurface groundwater flow in the hydrological cycle within the alpine area characterized by permafrost and/or seasonal frost are poorly known. We studied the role of permafrost in controlling groundwater flow and the hydrological connections between glaciers in high mountain and river in the low plain with hydraulic head, temperature, geochemical, and isotopic data. The study area was a catchment in the headwater region of the Heihe River in the northeastern Qinghai-Tibet Plateau. The groundwater in the high mountains mainly occurs as suprapermafrost groundwater, and in the moraine and fluvio-glacial deposits on the planation surfaces of higher hills suprapermafrost, intrapermafrost, and subpermafrost groundwater co-occur. Glacier and snow-meltwater are transported from the high mountains to the plain through stream channels, slope surfaces, and supra- and subpermafrost aquifers. Groundwater in the Quaternary aquifer under the piedmont plain is recharged by the lateral inflow from permafrost groundwaters and the infiltration of streams, and is discharged as baseflow to the stream in the north. Groundwater maintained stream flow over the cold season and significantly contributed to the stream flow during the rainy season. 3H and 14C data indicated that the age of supra- and sub-permafrost groundwater, and groundwater in Quaternary aquifer of seasonal frost zone, ranges from 30–60 years. Two proposed mechanisms contribute to seasonal variation of the aquifer water-conduction capacity: (1) surface drainage through the stream channel during the high-flow period, and (2) subsurface drainage to an artesian aquifer confined by stream icing and seasonal frost during the cold season.

scholarly journals Hydrological connectivity from glaciers to rivers in the Qinghai–Tibet Plateau: roles of suprapermafrost and subpermafrost groundwater

2017 ◽  
Vol 21 (9) ◽  
pp. 4803-4823 ◽  
Author(s):  
Rui Ma ◽  
Ziyong Sun ◽  
Yalu Hu ◽  
Qixin Chang ◽  
Shuo Wang ◽  
...  
Keyword(s):  
Groundwater Flow ◽  
Hydrological Cycle ◽  
Cold Season ◽  
Tibet Plateau ◽  
Heihe River ◽  
High Mountains ◽  
Stream Channels ◽  
Piedmont Plain ◽  
Water Conduction ◽  
Qinghai Tibet Plateau

Abstract. The roles of groundwater flow in the hydrological cycle within the alpine area characterized by permafrost and/or seasonal frost are poorly known. This study explored the role of permafrost in controlling groundwater flow and the hydrological connections between glaciers in high mountains and rivers in the low piedmont plain with respect to hydraulic head, temperature, geochemical and isotopic data, at a representative catchment in the headwater region of the Heihe River, northeastern Qinghai–Tibet Plateau. The results show that the groundwater in the high mountains mainly occurred as suprapermafrost groundwater, while in the moraine and fluvioglacial deposits on the planation surfaces of higher hills, suprapermafrost, intrapermafrost and subpermafrost groundwater cooccurred. Glacier and snow meltwaters were transported from the high mountains to the plain through stream channels, slope surfaces, and supra- and subpermafrost aquifers. Groundwater in the Quaternary aquifer in the piedmont plain was recharged by the lateral inflow from permafrost areas and the stream infiltration and was discharged as baseflow to the stream in the north. Groundwater maintained streamflow over the cold season and significantly contributed to the streamflow during the warm season. Two mechanisms were proposed to contribute to the seasonal variation of aquifer water-conduction capacity: (1) surface drainage through the stream channel during the warm period and (2) subsurface drainage to an artesian aquifer confined by stream icing and seasonal frost during the cold season.

scholarly journals Temporal Variations in the Quantity of Groundwater Flow in Nam Co Lake

Water ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 941 ◽  
Author(s):  
Yan Du ◽  
Zhide Huang ◽  
Mowen Xie ◽  
Asim Farooq ◽  
Chen Chen
Keyword(s):  
Groundwater Flow ◽  
Large Scale ◽  
Temporal Variations ◽  
Water Levels ◽  
Tibet Plateau ◽  
The Tibetan Plateau ◽  
Nam Co ◽  
Lake Water Level ◽  
Qinghai Tibet Plateau ◽  
Nam Co Lake

This paper aims to calculate and analyze the spatial and temporal variations in the groundwater flow quantity in Nam Co Lake based on the water balance principle. The results show that a large amount of groundwater was gradually lost and that, groundwater loss decreased from 1.9 billion m3 to 1.5 billion m3 from the period of 1980–1984 to 1995–2009. The comparative analysis in the current study indicates that the decrease in the groundwater index has a strong linear relationship with the temperature of the ground surface on the Tibetan Plateau, with a correlation coefficient as high as 0.92. Moreover, environmental variations such as large-scale engineering construction projects and increases in water storage may have played dominant roles in the sudden changes in the water quantities of plateau lakes (e.g., Nam Co Lake) during the periods of 1990–1995 and 2000–2009. The increased water levels resulted in reduced groundwater losses, which may lead to the substantial expansion or gradual shrinkage of the Qinghai–Tibet Plateau lakes over short periods of time. The results of this study provide an important reference for studying the mechanisms of lake water level changes on the Qinghai–Tibet Plateau.

scholarly journals Supplementary feeding of cattle-yak in the cold season alters rumen microbes, volatile fatty acids, and expression of SGLT1 in the rumen epithelium

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11048
Author(s):  
Yuzhu Sha ◽  
Jiang Hu ◽  
Bingang Shi ◽  
Renqing Dingkao ◽  
Jiqing Wang ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Community Structure ◽  
Microbial Community ◽  
Microbial Community Structure ◽  
Volatile Fatty Acids ◽  
Cold Season ◽  
Supplementary Feeding ◽  
Production Performance ◽  
Tibet Plateau ◽  
Qinghai Tibet Plateau

Cattle-yak, a hybrid offspring of yak (Bos grunniens) and cattle (Bos taurus), inhabit the Qinghai-Tibet Plateau at an altitude of more than 3,000 m and obtain nutrients predominantly through grazing on natural pastures. Severe shortages of pasture in the cold season leads to reductions in the weight and disease resistance of grazing cattle-yak, which then affects their production performance. This study aimed to investigate the effect of supplementary feeding during the cold season on the rumen microbial community of cattle-yak. Six cattle-yak (bulls) were randomly divided into two groups—“grazing + supplementary feeding” (G+S) (n = 3) and grazing (G) (n = 3)—and rumen microbial community structure (based on 16S rRNA sequencing), volatile fatty acids (VFAs), and ruminal epithelial sodium ion-dependent glucose transporter 1 (SGLT1) expression were assessed. There were significant differences in the flora of the two groups at various taxonomic classification levels. For example, Bacteroidetes, Rikenellaceae, and Rikenellaceae_RC9_gut_group were significantly higher in the G+S group than in the G group (P < 0.05), while Firmicutes and Christensenellaceae_R-7_group were significantly lower in the G+S group than in the G group (P < 0.05). Kyoto Encyclopedia of Genes and Genomes (KEGG) and Clusters of Orthologous Groups (COG) analyses revealed that functions related to carbohydrate metabolism and energy production were significantly enriched in the G+S group (P < 0.05). In addition, the concentration of total VFAs, along with concentrations of acetate, propionate, and butyrate, were significantly higher in the G+S group than in the G group (P < 0.05). Furthermore, SGLT1 expression in ruminal epithelial tissue was significantly lower in the G+S group (P < 0.01). Supplementary feeding of cattle-yak after grazing in the cold season altered the microbial community structure and VFA contents in the rumen of the animals, and decreased ruminal epithelial SGLT1 expression. This indicated that supplementary feeding after grazing aids rumen function, improves adaptability of cattle-yak to the harsh environment of the Qinghai-Tibet Plateau, and enhances ability of the animals to overwinter.

scholarly journals Impacts of Groundwater Flow on Evolution of a Thermokarst Lake in the Permafrost Region on the Qinghai-Tibet Plateau

2021 ◽  
Author(s):  
Wei Wang ◽  
Jinlong Li ◽  
Xianmin Ke ◽  
Kai Chen ◽  
Zeyong Gao ◽  
...  
Keyword(s):  
Groundwater Flow ◽  
Tibet Plateau ◽  
Permafrost Region ◽  
Permafrost Degradation ◽  
Ecological Changes ◽  
Lake Bottom ◽  
Explicit Consideration ◽  
Thawing Process ◽  
Qinghai Tibet Plateau ◽  
Permafrost Regions

Thermokarst lakes and permafrost degradation in the Qinghai-Tibet Plateau (QTP) resulting from global warming have been considerably affected the local hydrological and ecological process in recent decades. Simulation with coupled moisture-heat models that follows talik formation in the Beiluhe Basin (BLB) in the hinterland of permafrost regions on the QTP provides insight into the interaction between groundwater flow and freezing-thawing process. A total of 30 modified SUTRA schemes have been established to examine the effect of hydrodynamic forces, permeability and climate. The simulated results show that the hydrodynamic conditions impact the permafrost degradation surrounding the lake, thereby further affecting groundwater flow and late-stage freezing-thawing process. The thickness of the active layer varies with time and location under different permeability conditions, which significantly influences the occurrence of a breakthrough of the lake bottom. Warmer climate accelerates thawing and decreases the required time of formation of the breakthrough zone. Overall, these results indicate that explicit consideration of hydrologic process is critical to improve the understanding of environmental and ecological changes in cold regions.

scholarly journals Mapping High Mountain Lakes Using Space-Borne Near-Nadir SAR Observations

2018 ◽  
Vol 10 (9) ◽  
pp. 1418 ◽  
Author(s):  
Shengyang Li ◽  
Hong Tan ◽  
Zhiwen Liu ◽  
Zhuang Zhou ◽  
Yunfei Liu ◽  
...  
Keyword(s):  
Mountain Lakes ◽  
Tibet Plateau ◽  
High Mountain ◽  
Interferometric Imaging ◽  
Threshold Method ◽  
Ancillary Data ◽  
High Mountain Lakes ◽  
Observation Geometry ◽  
Qinghai Tibet Plateau ◽  
Theoretical Simulations

Near-nadir interferometric imaging SAR (Synthetic Aperture Radar) techniques are promising in measuring global water extent and surface height at fine spatial and temporal resolutions. The concept of near-nadir interferometric measurements was implemented in the experimental Interferometric Imaging Radar Altimeters (InIRA) mounted on Chinese Tian Gong 2 (TG-2) space laboratory. This study is focused on mapping the extent of high mountain lakes in the remote Qinghai–Tibet Plateau (QTP) areas using the InIRA observations. Theoretical simulations were first conducted to understand the scattering mechanisms under near-nadir observation geometry. It was found that water and surrounding land pixels are generally distinguishable depending on the degree of their difference in dielectric properties and surface roughness. The observed radar backscatter is also greatly influenced by incidence angles. A dynamic threshold method was then developed to detect water pixels based on the theoretical analysis and ancillary data. As assessed by the LandSat results, the overall classification accuracy is higher than 90%, though the classifications are affected by low backscatter possibly from very smooth water surface. The algorithms developed from this study can be extended to all InIRA land measurements and provide support for the similar space missions in the future.

scholarly journals Assessing the simulated soil thermal regime from Noah-MPLSM v1.1 for near-surface permafrost modeling on the Qinghai-Tibet Plateau

2020 ◽  
Author(s):  
Xiangfei Li ◽  
Tonghua Wu ◽  
Xiaodong Wu ◽  
Xiaofan Zhu ◽  
Guojie Hu ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Soil Temperature ◽  
Land Surface ◽  
Stomatal Resistance ◽  
Cold Season ◽  
Canopy Gap ◽  
Tibet Plateau ◽  
Surface Model ◽  
Near Surface ◽  
Qinghai Tibet Plateau

Abstract. Land surface models (LSMs) are effective tools for near-surface permafrost modeling. Extensive and rigorous model inter-comparison is of great importance before application due to the uncertainties in current LSMs. This study designed an ensemble of 6912 experiments to evaluate the Noah land surface model with multi-parameterization (Noah-MP) for soil temperature (ST) simulation, and investigate the sensitivity of parameterization schemes at a typical permafrost site on the Qinghai-Tibet Plateau. The results showed that Noah-MP generally underestimates ST, especially that during the cold season. In addition, the simulation uncertainty is greater in the cold season (October-April) and for the deep soil layers. ST is most sensitive to surface layer drag coefficient (SFC) while largely influenced by runoff and groundwater (RUN). By contrast, the influence of canopy stomatal resistance (CRS) and soil moisture factor for stomatal resistance (BTR) on ST is negligible. With limited impacts on ST simulation, vegetation model (VEG), canopy gap for radiation transfer (RAD) and snow/soil temperature time scheme (STC) are more influential on shallow ST, while super-cooled liquid water (FRZ), frozen soil permeability (INF) and lower boundary of soil temperature (TBOT) have greater impacts on deep ST. Furthermore, an optimal configuration of Noah-MP for permafrost modeling were extracted based on the connectivity between schemes, and they are: table leaf area index with calculated vegetation fraction, Jarvis scheme for CRS, Noah scheme for BTR, BATS model for RUN, Chen97 for SFC, zero canopy gap for RAD, variant freezing-point depression for FRZ, hydraulic parameters defined by soil moisture for INF, ST at 8 m for TBOT, and semi-implicit method for STC. The analysis of the model structural uncertainties and characteristics of each scheme would be constructive to a better understanding of the land surface processes on the QTP and further model improvements towards near-surface permafrost modeling using the LSMs.

scholarly journals Patterns and trends of high-impact weathers in China during 1959–2014

2015 ◽  
Vol 3 (10) ◽  
pp. 6149-6184
Author(s):  
J. Shi ◽  
K. Wen ◽  
L. Cui
Keyword(s):  
Eastern China ◽  
High Impact ◽  
Central China ◽  
Western China ◽  
Tibet Plateau ◽  
High Mountain ◽  
Weather Phenomenon ◽  
The Government ◽  
Social Vulnerabilities ◽  
Qinghai Tibet Plateau

Abstract. The spatial and temporal characteristics in the frequencies of four types of high-impact weathers (HIWs), i.e. snowfall, thunderstorm, foggy and hailstorm weathers were analyzed in China by using daily weather phenomenon data from 604 stations. Results indicate that snowfall, thunderstorm, foggy and hailstorm days showed significant decreasing trends with rates of 2.5, 2.6, 0.8 and 0.5 days per decade respectively, and snowfall, thunderstorm, foggy and hailstorm weather processes decreased significantly at rates of 0.3, 0.4, 0.1 and 0.1 times per decade during 1959–2014. Spatially, snowfall weathers were more in northeastern and western China, and thunderstorm weathers were more in southern and southwestern China. Foggy weathers were more in some high mountain stations, eastern China and central China, and hailstorm weathers were concentrated on Qinghai–Tibet Plateau. Over the past 56 years, snowfall days, thunderstorm days and thunderstorm weather processes decreased in most parts of China, with decreasing rates of 1.0–6.0 days, 1.5–8.0 days and 0.2–1.0 times per decade respectively. Hailstorm days decreased in northeastern China and most parts of northern and western China at a rate of 0.2–4.5 days per decade. The spatial trends of foggy days, foggy weather processes and snowfall weather processes were not significant in most parts of China. With climate change and rapidly economic development, more policies and strategies of reducing social vulnerabilities and/or exposures to HIWs are essential for the government and social publics.

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