Data-driven mapping of the spatial distribution and potential changes of frozen ground over the Tibetan Plateau

2019 ◽  
Vol 649 ◽  
pp. 515-525 ◽  
Author(s):  
Taihua Wang ◽  
Dawen Yang ◽  
Beijing Fang ◽  
Wencong Yang ◽  
Yue Qin ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Tibetan Plateau ◽  
Data Driven ◽  
The Tibetan Plateau ◽  
Frozen Ground

scholarly journals A new map of permafrost distribution on the Tibetan Plateau

2017 ◽  
Vol 11 (6) ◽  
pp. 2527-2542 ◽  
Author(s):  
Defu Zou ◽  
Lin Zhao ◽  
Yu Sheng ◽  
Ji Chen ◽  
Guojie Hu ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Spatial Data ◽  
Land Surface ◽  
Future Research ◽  
Data Sets ◽  
The Tibetan Plateau ◽  
Freezing And Thawing ◽  
Frozen Ground ◽  
Distribution Maps ◽  
Spatial Data Sets

Abstract. The Tibetan Plateau (TP) has the largest areas of permafrost terrain in the mid- and low-latitude regions of the world. Some permafrost distribution maps have been compiled but, due to limited data sources, ambiguous criteria, inadequate validation, and deficiency of high-quality spatial data sets, there is high uncertainty in the mapping of the permafrost distribution on the TP. We generated a new permafrost map based on freezing and thawing indices from modified Moderate Resolution Imaging Spectroradiometer (MODIS) land surface temperatures (LSTs) and validated this map using various ground-based data sets. The soil thermal properties of five soil types across the TP were estimated according to an empirical equation and soil properties (moisture content and bulk density). The temperature at the top of permafrost (TTOP) model was applied to simulate the permafrost distribution. Permafrost, seasonally frozen ground, and unfrozen ground covered areas of 1.06  ×  106 km2 (0.97–1.15  ×  106 km2, 90 % confidence interval) (40 %), 1.46  ×  106 (56 %), and 0.03  ×  106 km2 (1 %), respectively, excluding glaciers and lakes. Ground-based observations of the permafrost distribution across the five investigated regions (IRs, located in the transition zones of the permafrost and seasonally frozen ground) and three highway transects (across the entire permafrost regions from north to south) were used to validate the model. Validation results showed that the kappa coefficient varied from 0.38 to 0.78 with a mean of 0.57 for the five IRs and 0.62 to 0.74 with a mean of 0.68 within the three transects. Compared with earlier studies, the TTOP modelling results show greater accuracy. The results provide more detailed information on the permafrost distribution and basic data for use in future research on the Tibetan Plateau permafrost.

scholarly journals The Precipitation Variations in the Qinghai-Xizang (Tibetan) Plateau during 1961-2015

2017 ◽  
Author(s):  
Guoning Wan ◽  
Meixue Yang ◽  
Zhaochen Liu ◽  
Xuejia Wang ◽  
Xiaowen Liang
Keyword(s):  
Spatial Distribution ◽  
Tibetan Plateau ◽  
Precipitation Variability ◽  
Annual Precipitation ◽  
The Tibetan Plateau ◽  
Four Seasons ◽  
Winter Half ◽  
Summer Half ◽  
Surrounding Areas ◽  
Autumn And Winter

The Tibetan Plateau(TP) is known as ‘the water tower of Asian’, its precipitation variation play an important role in the eco-hydrological processes and water resources regimes. based on the monthly mean precipitation data of 65 meteorological stations over the Tibetan Plateau and the surrounding areas from 1961-2015,variations, trends and temporal-spatial distribution were analyzed, furthermore, the possible reasons were also discussed preliminarily. The main results are summarized as follows: the annual mean precipitation in the TP is 465.54mm during 1961-2015, among four seasons, the precipitation in summer accounts for 60.1% of the annual precipitation, the precipitation in summer half year (May.- Oct.) accounts for 91.0% while that in winter half year (Nov.- Apr.) only accounts for 9.0%; During 1961-2015, the annual precipitation variability is 0.45mm/a and the seasonal precipitation variability is 0.31mm/a, 0.13mm/a, -0.04mm/a and 0.04mm/a in spring, summer, autumn and winter respectively on the TP; The spatial distribution of precipitation can be summarized as decreasing from southeast to northwest in the TP, the trend of precipitation is decreasing with the increase of altitude, but the correlation is not significant. The rising of air temperature and land cover changes may cause the precipitation by changing the hydrologic cycle and energy budget, furthermore, different pattern of atmospheric circulation can also influence on precipitation variability in different regions.

scholarly journals A regional model to predict the distribution patterns of alpine permafrost in the western part of the Qilianshan Mountains, on the northeastern edge of the Qinghai-Tibetan Plateau

2009 ◽  
Vol 6 (4) ◽  
pp. 5243-5278
Author(s):  
Y. Sheng ◽  
J. Li ◽  
J. Wu ◽  
B. Ye ◽  
J. Wang
Keyword(s):  
Spatial Distribution ◽  
Tibetan Plateau ◽  
Solar Radiation ◽  
Distribution Patterns ◽  
Field Investigation ◽  
Regional Model ◽  
Distribution Map ◽  
Frozen Ground ◽  
Ground Temperatures ◽  
Incoming Solar Radiation

Abstract. A field investigation and measurement of ground temperatures in boreholes was carried out in the upper area of Shule River in the western part of the Qilianshan Mountains, in the northeast of the Qinghai-Tibetan Plateau in 2008. On the basis of this a sketchy distribution pattern of permafrost in this area was established. A regional permafrost model considering the effects of latitude, altitude, slope and aspect on distribution of permafrost was developed. The effect of latitude was calculated by the Gauss curve as proposed by Cheng, and then added to the effect of altitude. A linear relationship was found between altitude and the measured ground temperatures. For the effects of slope and aspect which mainly affected the amount and spatial distribution of the incoming solar radiation, a linear equation based on increments of the incoming solar radiation and the changes in ground temperature was used to evaluate their influence on the development of permafrost. A distribution map of the frozen ground, as well as a classification map of permafrost based on ground temperatures was produced using the ARCGIS software. In addition, the spatial distribution patterns of frozen ground and each permafrost type in this region were also analyzed.

Spatial-Temporal Distribution and Change of Seasonally Frozen Ground on the Tibetan Plateau from 1960 to 2014

2020 ◽  
Author(s):  
Siqiong Luo
Keyword(s):  
Tibetan Plateau ◽  
Regional Scale ◽  
Temporal Distribution ◽  
Thermal Conditions ◽  
The Tibetan Plateau ◽  
Frozen Ground ◽  
Important Indicator ◽  
Freeze Thaw ◽  
Start Date ◽  
Geographical Factors

<p>The change in spatial-temporal distribution of seasonally frozen ground (SFG) is an important indicator of climate change. Based on observed daily freeze depth of SFG from meteorological stations on the Tibetan Plateau (TP) from 1960 to 2014, the spatial-temporal characteristics and  trends in SFG were analyzed, and the relationships between them and climatic and geographical factors were explored. Spatial-temporal distribution of SFG on a regional scale was assessed by multiple regression functions. Results showed multi-year mean maximum freeze depth, freeze-thaw duration, freeze start date, and thaw end date demonstrate obvious distribution characteristics of climatic zones. A decreasing trend in maximum freeze depth and freeze-thaw duration occurred on the TP from 1960 to 2014. The freeze start date has been later and the thaw end date has been significantly earlier. Warming and wetting conditions of the soil resulted in a decrease in the maximum freeze depth and freeze-thaw duration, both spatially and temporally. The spatial distribution of SFG has been altered significantly by soil thermal conditions on the TP and could be assessed by elevation and latitude or by air temperature and precipitation, due to their high correlations. The regional average of maximum freeze depth and freeze-thaw duration caused by climatic and geographical factors was larger than those averaged using meteorological station data because most stations are located at lower altitudes. Maximum freeze depth and freeze-thaw duration has decreased sharply since 2000 on the entire TP.</p>

Sign in / Sign up

Export Citation Format

Share Document