A Study on the Hydrothermal Regime of Aeolian Sand and the Underlying Soil in the Frozen Soil Zone on the Qinghai-Tibetan Plateau

2021 ◽  
Vol 298-299 ◽  
pp. 108294
Author(s):  
Luyang Wang ◽  
Guanli Jiang ◽  
Ziteng Fu ◽  
Yali Liu ◽  
Siru Gao ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Frozen Soil ◽  
Aeolian Sand ◽  
Hydrothermal Regime ◽  
Soil Zone ◽  
Underlying Soil

Aeolian-fluvial sediments as palaeoenvironmental records in the eastern Qaidam Basin, NE Tibetan Plateau, since MIS6

2020 ◽  
Author(s):  
Lupeng Yu ◽  
Noam Greenbaum ◽  
Joel Roskin
Keyword(s):  
Tibetan Plateau ◽  
Large Scale ◽  
Asian Summer Monsoon ◽  
Qaidam Basin ◽  
Sedimentary Facies ◽  
Fluvial Sediments ◽  
Last Deglaciation ◽  
Aeolian Sand ◽  
The Holocene ◽  
New Interpretation

<p>Aeolian sediments sensitively respond to climatic changes. Continuous Quaternary loess deposits plays important roles in palaeoclimatic reconstructions. However, application of aeolian sand for such reconstructions is limited by its discontinuous depositional nature. Aeolian-fluvial sediments are widely distributed in arid and semi-arid regions where dunefields interact with watercourses. These palaeoenvironmental archives have been sparsely studied mainly due to their mixed character that requires new interpretation approaches.</p><p>We have found that climate fluctuations lead good preservation of aeolian sand deposits that underlay fluvial sediments, making the sedimentary records more continuous. In this study, aeolian and fluvial sediments (elevation of 3400-3500 m a.s.l.) were studied in the eastern margin of Qaidam Basin (QB), northeastern Tibetan Plateau to reconstruct palaeoenvironmental and palaeoclimatic changes since the MIS6, based on sedimentary facies, 120 OSL ages (with age range of 143-1 ka), grain size distribution, MS, TOC, and carbonates.</p><p>Within a deeply (10-65 m) incised 1.5-km-long valley, aeolian-fluvial cycles displayed frequent dune-damming of a stream since MIS6. Dune sands were dated to MIS's 6, 5d, 4, 3c, 3a, and the last deglaciation, while fluvial and dune-dammed lake sediments were dated to MIS's 5c, 3c, 3a, and deglaciation.</p><p>Large-scale A-F interactions mainly occurred during MIS3 and deglaciation, when the QB dunefields were still mobile after LGM and MIS4 and precipitation started to increase. No ages fall within LGM, suggesting an extremely arid and windy environment in which the dune sand kept reworking and cannot record OSL ages. This further confirms that only with the covering of fluvial sediments, aeolian sand can be well preserved. On the other hand, OSL ages of aeolian sand might only present periods when aeolian activities were not too strong.</p><p>During the Holocene, loess-paleosol accumulated in the QB margins, with loess accumulation since 10 ka and development of paleosols during ca. 8.5-3 ka, the Holocene optimum. These results demonstrate that aeolian-fluvial sediments are important palaeoenvironmental records in arid region and indicate that the climate of the eastern QB was mainly controlled by the temperature (solar insolation) and precipitation (Asian Summer Monsoon) changes since MIS6. <strong> </strong></p>

Unraveling the groundwater transit time control of permafrost derived dissolved organic carbon processing in a hillslope headwater watershed of Qinghai-Tibetan Plateau

2021 ◽  
Author(s):  
Yuqin Sun ◽  
Kale Clauson ◽  
Min Zhou ◽  
Ziyong Sun ◽  
Chunmiao Zheng ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Transit Time ◽  
Mean Transit Time ◽  
Frozen Soil ◽  
Permafrost Region ◽  
Transport Pathways ◽  
Microbial Utilization ◽  
Time Control

<p>Climate warming leads to massive thaws of the northern permafrost that has increased the release of soil organic carbon (SOC) to streams and rivers partly as dissolved organic carbon (DOC). The transport pathways of SOC releasing into porewater and entering into stream are undergoing profound hydrological changes triggered by permafrost thawing, yet the role that the groundwater plays in processing the permafrost derived DOC is ambiguous. Unravelling how subsurface flow affects permafrost sourced DOC processing is important especially in alpine watersheds of high-altitude permafrost region with extensive surface – groundwater interaction. Here, eight types of water were sampled from a small (25 km<sup>2</sup>), alpine (elevation 2960 to 4820 m a.s.l) watershed named Hulugou watershed (HLGW) with variably degraded permafrost in the Qinghai-Tibetan Plateau (QTP) in July and September of 2012, 2013 and 2018. The three end-members (glacier-snow meltwater, precipitation, and frozen soil meltwater) analysis suggested contribution of frozen soil meltwater to all types of water with variable DOC levels (0.4 to 22.6 mg L<sup>-1</sup>, n = 113), as constrained by <em>δ</em><sup>18</sup>O and electrical conductivity (EC). Spatial patterns of DOC quantity and quality between stream and subsurface waters (groundwater, spring, and seepage-II) point to differences in surface – groundwater exchanges in the upper-, mid- and lower stretch of the watershed. To evaluate the extent of DOC loss (ΔDOC), ΔDOC is calculated using an initial DOC (DOC<sub>0</sub>) estimated from mixing of three endmembers, minus the measured DOC concentration. The significant correlations between ΔDOC with proportion of protein-like fluorophores (<em>r</em> = -0.69, <em>p</em> < 0.01) and relatively aromatic C levels (<em>r</em> = -0.62, <em>p</em> = 0.02) indicate ΔDOC corresponding to the extent of microbial utilization of DOC in subsurface environment. Using previously established DOC biodegradation kinetics of 0.25 d<sup>-1</sup> in headwaters of QTP, the mean transit time of groundwater is estimated to be 6 and 20 days based on changes in subsurface ΔDOC of 32% and 74% from the outlet of HLGW for July and September, respectively. The more rapid groundwater transit time corresponds to the higher concentration and more boilable DOC in July (3.5 mg L<sup>-1</sup>, protein-like: 98%) than in September (1.0 mg L<sup>-1</sup>, protein-like: 53±26%). Together with the mass balance of DOC input and export fluxes showing half loss of C in HLGW, our results indicate that rapid groundwater transit time is associated with permafrost derived DOC processing in alpine hillslope subject to warming.</p>

scholarly journals Applied Research on the Eco-Bags Structure for the Riverside collapse Slope in Seasonal Frozen Soil Zone

2012 ◽  
Vol 28 ◽  
pp. 855-859 ◽  
Author(s):  
Zheng Duo ◽  
Zhou Jiyuan ◽  
Yang Jinliang ◽  
Zhu Zhenxue
Keyword(s):  
Applied Research ◽  
Frozen Soil ◽  
Soil Zone ◽  
Seasonal Frozen Soil

scholarly journals Simulation Analysis of the Long-Term Stability for Frozen Soil Roadbed

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Xiaohui Liu ◽  
Jianqing Jia ◽  
Yibo Zhang
Keyword(s):  
Numerical Simulation ◽  
Global Warming ◽  
Tibetan Plateau ◽  
Simulation Analysis ◽  
Frozen Soil ◽  
Temperature Fields ◽  
Term Stability ◽  
Long Term Stability ◽  
Horizontal Displacements

The global warming will lead to rising temperature in Tibetan plateau which will cause some trouble to the long-term stability of frozen soil roadbed. Of course, the temperature is the most important to stability analysis and study of frozen soil roadbed. In this paper, taking the frozen soil roadbed in Tibetan plateau as an example, the numerical simulation model is established. Firstly, the characteristics of temperature fields of frozen soil roadbed in the future 50 years are analyzed, and then the vertical and horizontal displacements without load and under dynamic load are analyzed.

Late Quaternary aeolian activity in Gonghe Basin, northeastern Qinghai-Tibetan Plateau, China

2013 ◽  
Vol 79 (3) ◽  
pp. 403-412 ◽  
Author(s):  
Mingrui Qiang ◽  
Fahu Chen ◽  
Lei Song ◽  
Xingxing Liu ◽  
Mingzhi Li ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Late Quaternary ◽  
Optically Stimulated Luminescence ◽  
Aeolian Sand ◽  
Aeolian Deposits ◽  
Effective Moisture ◽  
Aeolian Activity ◽  
History Of ◽  
Gonghe Basin ◽  
Semi Arid

AbstractAeolian deposits at four sites in the Gonghe Basin were used to reconstruct the history of aeolian activity over the late Quaternary. These deposits include well-sorted aeolian sand, paleosols and/or loess. Aeolian sand represents dune-field expansion and/or dune buildup, whereas paleosols indicate stabilization of dunes, accompanying ameliorated vegetation cover. On the basis of 25 dates by optically stimulated luminescence (OSL), it appears that aeolian activities occurred episodically at 33.5, 20.3, 13.9, 11.8–11.0, 9.4, 7.8, and 5.7 (5.5) ka, which is largely consistent with the recent findings from the adjacent semi-arid areas. Aeolian sand mobility occurring during the early to mid Holocene conflicts with a climatic optimum inferred from lacustrine records in the northeastern Qinghai-Tibetan Plateau. This inconsistency may be resolved by interpreting aeolian activity as a response to decreased effective moisture due to enhanced evaporation, induced by higher summer insolation at that time, together with local terrain and its effects on moisture. Our results suggest that aeolian sand and paleosol cannot be simply ascribed to regional dry and wet climates, respectively, and they most likely reflect changes in effective moisture.

Remote sensing spatiotemporal patterns of frozen soil and the environmental controls over the Tibetan Plateau during 2002–2016

2020 ◽  
Vol 247 ◽  
pp. 111927 ◽  
Author(s):  
Guanheng Zheng ◽  
Yuting Yang ◽  
Dawen Yang ◽  
Baptiste Dafflon ◽  
Yonghong Yi ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Tibetan Plateau ◽  
Frozen Soil ◽  
Spatiotemporal Patterns ◽  
The Tibetan Plateau ◽  
Environmental Controls

scholarly journals Impact of frozen soil processes on soil thermal characteristics at seasonal to decadal scales over the Tibetan Plateau and North China

2020 ◽  
Author(s):  
Qian Li ◽  
Yongkang Xue ◽  
Ye Liu
Keyword(s):  
Tibetan Plateau ◽  
Soil Temperature ◽  
Temperature Profile ◽  
Land Surface ◽  
North China ◽  
Thermal Characteristics ◽  
Frozen Soil ◽  
The Tibetan Plateau ◽  
Soil Processes ◽  
Freeze Thaw

Abstract. Frozen soil processes are of great importance in controlling surface water and energy balances during the cold season and in cold regions. Over recent decades, considerable frozen soil degradation and surface soil warming have been reported over the Tibetan Plateau and North China, but most land surface models have difficulty in capturing the freeze-thaw cycle and few validations focus on the effects of frozen soil processes on soil thermal characteristics in these regions. This paper addresses these issues by introducing a physically more realistic and computationally more stable and efficient frozen soil module (FSM) into a land surface model—the third-generation Simplified Simple Biosphere model (SSiB3-FSM). To overcome the difficulties in achieving stable numerical solutions for frozen soil, a new semi-implicit scheme and a physics-based freezing-thawing scheme were applied to solve the governing equations. The performance of this model, as well as the effects of frozen soil process on the soil temperature profile and soil thermal characteristics, were investigated over the Tibetan Plateau and North China using observation and models. Results show that the SSiB3 model with the FSM produces more realistic soil temperature profile and its seasonal variation than that without FSM during the freezing and thawing periods. The freezing process in soil delays the winter cooling, while the thawing process delays the summer warming. The time lag and amplitude damping of temperature become more pronounced with increasing depth. These processes are well simulated in SSiB3-FSM. The freeze-thaw processes could increase the simulated phase lag days and land memory at different soil depths, as well as the soil memory change with the soil thickness. Furthermore, compared with observations, SSiB3-FSM produces a realistic change of maximum frozen soil depth at decadal scales. This study shows the soil thermal characteristics at seasonal to decadal scales over frozen ground can be greatly improved in SSiB3-FSM and SSiB3-FSM can be used as an effective model for TP and NC simulation during cold reasons.

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