scholarly journals Thermal Regime and Variations in the Island Permafrost Near the Northern Permafrost Boundary in Xidatan, Qinghai–Tibet Plateau

2021 ◽  
Vol 9 ◽  
Author(s):  
Guoan Yin ◽  
Jing Luo ◽  
Fujun Niu ◽  
Zhanju Lin ◽  
Minghao Liu
Keyword(s):  
Thermal Regime ◽  
Degradation Process ◽  
Tibet Plateau ◽  
Deep Soil ◽  
Ground Temperatures ◽  
Air Temperatures ◽  
Degradation Pattern ◽  
Permafrost Table ◽  
Increasing Trend ◽  
Qinghai Tibet Plateau

Although the thermal regime and degradation of permafrost on the Qinghai-Tibet Plateau (QTP) have been widely documented, little information exists regarding the island permafrost in the area. Ground temperatures were therefore measured for 8 years (2013–2020) at a permafrost island and at two contrasting sites in the Xidatan region to elucidate the permafrost in this area. Results indicate that the ground temperatures in the island permafrost were markedly higher than those at the same depth in the nearby marginal permafrost and the interior continuous permafrost. In addition, a distinct increasing trend was observed in the ground temperature of the island permafrost over the past 8 years, and warming was signficanty faster in the deep soil than in the topsoil, indicating a bottom–up degradation pattern in the island permafrost. Moreover, due to the persistent increase in the thickness of the active-layer and the decrease in the depth of permafrost table, the permafrost island abruptly disappeared in 2018, which may be attributed to the anomalously high air temperatures that occurred in 2016 and 2017. The results of this study may provide references for understanding of the thermal regime and degradation process of island permafrost on the QTP.

Heat Effect Analysis of Buried Oil Pipeline in the Qinghai-Tibet Plateau

2014 ◽  
Vol 501-504 ◽  
pp. 211-217
Author(s):  
Wei Bo Liu ◽  
Wen Bing Yu ◽  
Xin Yi ◽  
Lin Chen
Keyword(s):  
Temperature Field ◽  
Frozen Soil ◽  
Operating Conditions ◽  
Tibet Plateau ◽  
Soil Mechanic ◽  
Insulation Layer ◽  
Effect Analysis ◽  
Oil Pipeline ◽  
Permafrost Table ◽  
Qinghai Tibet Plateau

The Geermu-Lasa oil pipeline was located in the Qinghai-Tibet Plateau permafrost regions. The building and operating of pipeline will change the temperature field of soil around it, which can lead to changes of frozen soil mechanic properties, and this will induces deformation or even fracture of pipeline. These phenomena will affect the normal transportation of oil. In this paper, temperature field around the pipelines were analyzed due to different pipe diameters and different insulation layer thicknesses in the way of finite element method. The rule of thawing and freezing of soil around the pipeline in an annual cycle was obtained. Artificial permafrost table variations under the pipeline were also obtained due to different operating conditions. For 30cm diameter pipeline with 7cm insulation layer, its artificial permafrost table depth change value is just 0.48m after 30-year running. These analysis results can provide references to the construction of the new Geermu-Lasa oil pipeline.

scholarly journals Active layer thermal regime in two climatically contrasted sites of the Antarctic Peninsula region

2016 ◽  
Vol 42 (2) ◽  
pp. 457 ◽  
Author(s):  
F. Hrbáček ◽  
M. Oliva ◽  
K. Laska ◽  
J. Ruiz-Fernández ◽  
M. A. De Pablo ◽  
...  
Keyword(s):  
Active Layer ◽  
Antarctic Peninsula ◽  
Thermal Regime ◽  
Active Layer Thickness ◽  
Mean Annual Temperature ◽  
Climate Trends ◽  
Ground Temperatures ◽  
Air Temperatures ◽  
Discontinuous Permafrost ◽  
The Antarctic

Permafrost controls geomorphic processes in ice-free areas of the Antarctic Peninsula (AP) region. Future climate trends will promote significant changes of the active layer regime and permafrost distribution, and therefore a better characterization of present-day state is needed. With this purpose, this research focuses on Ulu Peninsula (James Ross Island) and Byers Peninsula (Livingston Island), located in the area of continuous and discontinuous permafrost in the eastern and western sides of the AP, respectively. Air and ground temperatures in as low as 80 cm below surface of the ground were monitored between January and December 2014. There is a high correlation between air temperatures on both sites (r=0.74). The mean annual temperature in Ulu Peninsula was -7.9 ºC, while in Byers Peninsula was -2.6 ºC. The lower air temperatures in Ulu Peninsula are also reflected in ground temperatures, which were between 4.9 (5 cm) and 5.9 ºC (75/80 cm) lower. The maximum active layer thickness observed during the study period was 52 cm in Ulu Peninsula and 85 cm in Byers Peninsula. Besides climate, soil characteristics, topography and snow cover are the main factors controlling the ground thermal regime in both areas.

Geohazards and thermal regime analysis of oil pipeline along the Qinghai–Tibet Plateau Engineering Corridor

2016 ◽  
Vol 83 (1) ◽  
pp. 193-209 ◽  
Author(s):  
Wenbing Yu ◽  
Fenglei Han ◽  
Weibo Liu ◽  
Stuart A. Harris
Keyword(s):  
Thermal Regime ◽  
Tibet Plateau ◽  
Oil Pipeline ◽  
Qinghai Tibet Plateau ◽  
Regime Analysis

scholarly journals Analysis on the Temporal and Spatial Characteristics of the Shallow Soil Temperature of the Qinghai-Tibet Plateau

2021 ◽  
Author(s):  
Yujie Li ◽  
Cunjie Zhang ◽  
Zhenchao Li ◽  
Liwei Yang ◽  
Xiao Jin ◽  
...  
Keyword(s):  
Soil Temperature ◽  
Observational Data ◽  
Temperature Increase ◽  
Soil Layer ◽  
Tibet Plateau ◽  
Shallow Soil ◽  
Increasing Trend ◽  
Temporal And Spatial ◽  
Region 10 ◽  
Qinghai Tibet Plateau

Abstract Shallow soil refers to the soil layer within 50 cm underground. Shallow soil temperature (ST) affects many processes that occur in the soil. Therefore, the study of shallow ST is of great significance in understanding energy, hydrological cycles and climate change. This work collected the observational data from 141 meteorological stations on the Qinghai-Tibet Plateau from 1981 to 2020, analyzed the ST as well as its temporal and spatial change characteristics at different levels. The results show that: 1) The shallow ST has a gradually increasing trend from north to south, from west to east. From the perspective of time characteristics, the increasing trend is obvious. The temperature increase of 0–20 cm (the surface layer of the shallow soil) is roughly the same. The average annual is 9.15–9.57 ℃, the interdecadal variabilities are 0.49–0.53 K/10a. The average annual of 40 cm (the bottom layer) is 8.69 ℃, the interdecadal variability reaches by 0.98 K/10a; 2) Judging from the 12 regions of 20 cm, the temperature increase trend is obvious, but there are certain regional differences. The average value ranges from 4.3 ℃ (region 4, Qaidam Plateau) to 18.1 ℃ (region 10, Southeast Qinghai-Tibet Plateau), the difference is nearly 14 K. The standard deviation ranges from 0.38 K (region 10) to 0.82 K (region 11, Northern Qiangtang Plateau); 3) The results of the reanalysis data are lower than the observational data. This work is significant for understanding the characteristics of the ST evolution and the land-atmosphere interaction on the Qinghai-Tibet Plateau.

scholarly journals Dynamics of lake area on the Qinghai-Tibet plateau from 2000 to 2015

2019 ◽  
Vol 2 ◽  
pp. 1-7 ◽  
Author(s):  
Xianghong Che ◽  
Min Feng ◽  
Jiping Liu ◽  
Yong Wang ◽  
Qing Sun
Keyword(s):  
Yellow River ◽  
Global Scale ◽  
Water Bodies ◽  
Tibet Plateau ◽  
Medium Size ◽  
Power Exponent ◽  
Lake Area ◽  
Water Detection ◽  
Increasing Trend ◽  
Qinghai Tibet Plateau

<p><strong>Abstract.</strong> The distribution of lakes in space and its change over time are closely related to many environmental and ecological issues, and are important factors that must be considered in human socio-economic development. In this paper, the water detection method is utilized to derive monthly water bodies, and then a seed set expansion approach was explored to extract lakes larger than 0.1&amp;thinsp;km<sup>2</sup>. Since lakes number and size can effectively reflect the distribution characteristics of water bodies, their change of the number, area and distribution are analyzed. The results shows there is a prominent power exponent relation between lake size and lake number for the Qinghai-Tibet plateau (QTP), which is similar to existing analysis of global scale. The number density of medium size of lakes on the QTP is higher than other types of lakes. The number of lakes displayed a decreasing trend from 2000 to 2015 with the <i>R</i><sup>2</sup> of 0.41. There was an increasing trend with an increasing rate of 356.86&amp;thinsp;km<sup>2</sup>/year (0.72%). Specifically, 46.54% of lakes area are increasing, and mostly distributed in Alpine grassland and shrub woodlands zone of the central Tibetan plateau. Shrinking lakes mostly with the area less than 10&amp;thinsp;km<sup>2</sup> are situated on the woodland and shrub and grass areas in south-eastern Tibet. Finally, the analysis of monthly lake area of four lakes at the source of the Yellow River demonstrates the lakes area of each month from June to September witness an increasing trend, and the largest increasing rate is on June, which has a strong seasonality.</p>

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