{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,4]],"date-time":"2026-03-04T03:19:46Z","timestamp":1772594386936,"version":"3.50.1"},"reference-count":89,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2021,1,5]],"date-time":"2021-01-05T00:00:00Z","timestamp":1609804800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"the Strategic Priority Research Program of the Chinese Academy of Sciences","award":["XDA20100101"],"award-info":[{"award-number":["XDA20100101"]}]},{"name":"the National Key Research and Development Program of China","award":["2019YFC0507404"],"award-info":[{"award-number":["2019YFC0507404"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>The permafrost in the Qilian Mountains (QLMs), the northeastern margin of the Qinghai\u2013Tibet Plateau, changed dramatically in the context of climate warming and increasing anthropogenic activities, which poses significant influences on the stability of the ecosystem, water resources, and greenhouse gas cycles. Yet, the characteristics of the frozen ground in the QLMs are largely unclear regarding the spatial distribution of active layer thickness (ALT), the maximum frozen soil depth (MFSD), and the temperature at the top of the permafrost or the bottom of the MFSD (TTOP). In this study, we simulated the dynamics of the ALT, TTOP, and MFSD in the QLMs in 2004\u20132019 in the Google Earth Engine (GEE) platform. The widely-adopted Stefan Equation and TTOP model were modified to integrate with the moderate-resolution imaging spectroradiometer (MODIS) land surface temperature (LST) in GEE. The N-factors, the ratio of near-surface air to ground surface freezing and thawing indices, were assigned to the freezing and thawing indices derived with MODIS LST in considerations of the fractional vegetation cover derived from MODIS normalized difference vegetation index (NDVI). The results showed that the GEE platform and remote sensing imagery stored in Google cloud could be quickly and effectively applied to obtain the spatial and temporal variation of permafrost distribution. The area with TTOP &lt; 0 \u00b0C is 8.4 \u00d7 104 km2 (excluding glaciers and lakes) and accounts for 46.6% of the whole QLMs, the regional mean ALT is 2.43 \u00b1 0.44 m, while the regional mean MFSD is 2.54 \u00b1 0.45 m. The TTOP and ALT increase with the decrease of elevation from the sources of the sub-watersheds to middle and lower reaches. There is a strong correlation between TTOP and elevation (slope = \u22121.76 \u00b0C km\u22121, p &lt; 0.001). During 2004\u20132019, the area of permafrost decreased by 20% at an average rate of 0.074 \u00d7 104 km2\u00b7yr\u22121. The regional mean MFSD decreased by 0.1 m at a rate of 0.63 cm\u00b7yr\u22121, while the regional mean ALT showed an exception of a decreasing trend from 2.61 \u00b1 0.45 m during 2004\u20132005 to 2.49 \u00b1 0.4 m during 2011\u20132015. Permafrost loss in the QLMs in 2004\u20132019 was accelerated in comparison with that in the past several decades. Compared with published permafrost maps, this study shows better calculation results of frozen ground in the QLMs.<\/jats:p>","DOI":"10.3390\/rs13010149","type":"journal-article","created":{"date-parts":[[2021,1,5]],"date-time":"2021-01-05T10:35:12Z","timestamp":1609842912000},"page":"149","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":20,"title":["Mapping Frozen Ground in the Qilian Mountains in 2004\u20132019 Using Google Earth Engine Cloud Computing"],"prefix":"10.3390","volume":"13","author":[{"given":"Yuan","family":"Qi","sequence":"first","affiliation":[{"name":"Key Laboratory of Remote Sensing of Gansu Province, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China"}]},{"given":"Shiwei","family":"Li","sequence":"additional","affiliation":[{"name":"Piesat Information Technology Co., Ltd., Beijing 100000, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7774-4612","authenticated-orcid":false,"given":"Youhua","family":"Ran","sequence":"additional","affiliation":[{"name":"Key Laboratory of Remote Sensing of Gansu Province, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China"}]},{"given":"Hongwei","family":"Wang","sequence":"additional","affiliation":[{"name":"Key Laboratory of Remote Sensing of Gansu Province, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China"}]},{"given":"Jichun","family":"Wu","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Frozen Soil Engineering, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6854-9898","authenticated-orcid":false,"given":"Xihong","family":"Lian","sequence":"additional","affiliation":[{"name":"Key Laboratory of Remote Sensing of Gansu Province, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China"},{"name":"University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing 100049, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5844-3638","authenticated-orcid":false,"given":"Dongliang","family":"Luo","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Frozen Soil Engineering, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China"}]}],"member":"1968","published-online":{"date-parts":[[2021,1,5]]},"reference":[{"key":"ref_1","unstructured":"Everdingen, V. (2005). Multi-Language Glossary of Permafrost and Related Ground-Ice Terms, National Snow and Ice Data Center."},{"key":"ref_2","first-page":"185","article-title":"Problems on Zonation of High-Altitude Permafrost","volume":"39","author":"Cheng","year":"1984","journal-title":"Acta Geogr. Sin."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"595","DOI":"10.5194\/tc-12-595-2018","article-title":"Climate warming over the past half century has led to thermal degradation of permafrost on the Qinghai\u2013Tibet Plateau","volume":"12","author":"Ran","year":"2018","journal-title":"Cryosphere"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"607","DOI":"10.5194\/tc-6-607-2012","article-title":"Thermal state of the active layer and permafrost along the Qinghai-Xizang (Tibet) Railway from 2006 to 2010","volume":"6","author":"Wu","year":"2012","journal-title":"Cryosphere"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"257","DOI":"10.1002\/ppp.1988","article-title":"Elevation-dependent thermal regime and dynamics of frozen ground in the Bayan Har Mountains, northeastern Qinghai-Tibet Plateau, SW China","volume":"29","author":"Luo","year":"2018","journal-title":"Permafr. Periglac. Process."},{"key":"ref_6","first-page":"418","article-title":"Permafrost in the middle-east section of Qilian Mountains (I): Distribution of permafrost","volume":"29","author":"Wu","year":"2007","journal-title":"J. Glaciol. Geocryol."},{"key":"ref_7","first-page":"426","article-title":"Permafrost in the middle-east section of Qilian Mountains (II): Characters of permafrost","volume":"29","author":"Wu","year":"2007","journal-title":"J. Glaciol. Geocryol."},{"key":"ref_8","first-page":"571","article-title":"Permafrost in Source Areas of Shule River in Qilian Mountains","volume":"64","author":"Wu","year":"2009","journal-title":"Acta Geogr. Sin."},{"key":"ref_9","first-page":"27","article-title":"The characteristics and changing tendency of permafrost in the source regions of the Datong River, Qilian Mountains","volume":"37","author":"Wang","year":"2015","journal-title":"J. Glaciol. Geocryol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"2783","DOI":"10.1360\/TB-2019-0191","article-title":"Characteristic, changes and impacts of permafrost on Qinghai-Tibet Plateau","volume":"64","author":"Cheng","year":"2019","journal-title":"Chinese Sci. Bull."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"264","DOI":"10.1038\/s41467-018-08240-4","article-title":"Permafrost is warming at a global scale","volume":"10","author":"Biskaborn","year":"2019","journal-title":"Nat. Commun."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"149","DOI":"10.1016\/j.gloplacha.2014.09.002","article-title":"Changes in active-layer thickness and near-surface permafrost between 2002 and 2012 in alpine ecosystems, Qinghai\u2013Xizang (Tibet) Plateau, China","volume":"124","author":"Wu","year":"2015","journal-title":"Glob. Planet. Chang."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"7935","DOI":"10.1029\/2018JD028442","article-title":"Thermal Characteristics and Recent Changes of Permafrost in the Upper Reaches of the Heihe River Basin, Western China","volume":"123","author":"Cao","year":"2018","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"125","DOI":"10.1029\/2019JG005086","article-title":"Northern Hemisphere greening in association with warming permafrost","volume":"125","author":"Peng","year":"2020","journal-title":"J. Geophys. Res. Biogeosciences"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"2667","DOI":"10.5194\/tc-12-2667-2018","article-title":"Characteristics and fate of isolated permafrost patches in coastal Labrador, Canada","volume":"12","author":"Way","year":"2018","journal-title":"Cryosphere"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"73","DOI":"10.1002\/ppp.1972","article-title":"Environmental controls on ground temperature and permafrost in Labrador, northeast Canada","volume":"29","author":"Way","year":"2018","journal-title":"Permafr. Periglac. Process."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"2201","DOI":"10.1038\/s41467-020-15725-8","article-title":"Fast response of cold ice-rich permafrost in northeast Siberia to a warming climate","volume":"11","author":"Nitzbon","year":"2020","journal-title":"Nat. Commun."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"eaaz3513","DOI":"10.1126\/sciadv.aaz3513","article-title":"Permafrost thawing puts the frozen carbon at risk over the Tibetan Plateau","volume":"6","author":"Wang","year":"2020","journal-title":"Sci. Adv."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"135127","DOI":"10.1016\/j.scitotenv.2019.135127","article-title":"Permafrost degradation enhances the risk of mercury release on Qinghai-Tibetan Plateau","volume":"708","author":"Mu","year":"2020","journal-title":"Sci. Total. Environ."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Zhang, Z., Wang, M., Wu, Z., and Liu, X. (2019). Permafrost Deformation Monitoring Along the Qinghai-Tibet Plateau Engineering Corridor Using InSAR Observations with Multi-Sensor SAR Datasets from 1997\u20132018. Sensors, 19.","DOI":"10.3390\/s19235306"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"2531","DOI":"10.1002\/hyp.8025","article-title":"Characteristics of land surface heat and water exchange under different soil freeze\/thaw conditions over the central Tibetan Plateau","volume":"25","author":"Guo","year":"2011","journal-title":"Hydrol. Process."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1","DOI":"10.3402\/tellusb.v68.30467","article-title":"Tundra permafrost thaw causes significant shifts in energy partitioning","volume":"68","author":"Stiegler","year":"2016","journal-title":"Tellus B Chem. Phys. Meteorol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"663","DOI":"10.1038\/nclimate1580","article-title":"Different glacier status with atmospheric circulations in Tibetan Plateau and surroundings","volume":"2","author":"Yao","year":"2012","journal-title":"Nat. Clim. Chang."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1382","DOI":"10.1126\/science.1183188","article-title":"Climate change will affect the Asian water towers","volume":"328","author":"Immerzeel","year":"2010","journal-title":"Science"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"20815","DOI":"10.1029\/2008GL035867","article-title":"World water tower: An atmospheric perspective","volume":"35","author":"Xu","year":"2008","journal-title":"Geophys. Res. Lett."},{"key":"ref_26","first-page":"1203","article-title":"Asian Water Tower Change and Its Impacts","volume":"34","author":"Yao","year":"2019","journal-title":"Bull. Chin. Acad. Sci."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"32","DOI":"10.1016\/j.coldregions.2011.12.006","article-title":"Simulation of decadal alpine permafrost distributions in the Qilian Mountains over past 50 years by using Logistic Regression Model","volume":"73","author":"Zhao","year":"2012","journal-title":"Cold Reg. Sci. Technol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"322","DOI":"10.1002\/ppp.1756","article-title":"Distribution of Permafrost in China: An Overview of Existing Permafrost Maps","volume":"23","author":"Ran","year":"2012","journal-title":"Permafr. Periglac. Process."},{"key":"ref_29","unstructured":"Li, S., and Cheng, G. (1996). Map of Permafrost on Qinghai-Tibetan Plateau (1:3,000,000), Gansu Culture Press."},{"key":"ref_30","unstructured":"Zhou, Y., Qiu, G., Guo, D., Cheng, G., and Li, S. (2000). Geocryology in China, Science Press."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"292","DOI":"10.1002\/ppp.1758","article-title":"Simulation of the Decadal Permafrost Distribution on the Qinghai-Tibet Plateau (China) over the Past 50 Years","volume":"23","author":"Cheng","year":"2012","journal-title":"Permafr. Periglac. Process."},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Zhao, S., Zhang, S., Cheng, W., and Zhou, C. (2019). Model Simulation and Prediction of Decadal Mountain Permafrost Distribution Based on Remote Sensing Data in the Qilian Mountains from the 1990s to the 2040s. Remote Sens., 11.","DOI":"10.3390\/rs11020183"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"5216","DOI":"10.1002\/jgrd.50457","article-title":"Simulation of permafrost and seasonally frozen ground conditions on the Tibetan Plateau, 1981-2010","volume":"118","author":"Guo","year":"2013","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"10","DOI":"10.1016\/j.quaint.2019.06.006","article-title":"Response of frozen ground under climate change in the Qilian Mountains, China","volume":"523","author":"Wang","year":"2019","journal-title":"Quat. Int."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"2928","DOI":"10.1360\/TB-2019-0209","article-title":"Tightening ecological management facilitates green development in the Qilian Mountains","volume":"64","author":"Li","year":"2019","journal-title":"Chin. Sci. Bull."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"102904","DOI":"10.1016\/j.coldregions.2019.102904","article-title":"Changes in the permafrost temperatures from 2003 to 2015 in the Qinghai-Tibet Plateau","volume":"169","author":"Zhongqiong","year":"2020","journal-title":"Cold Reg. Sci. Technol."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1007\/s00704-020-03291-4","article-title":"Variability of soil freeze depth in association with climate change from 1901 to 2016 in the upper Brahmaputra River Basin, Tibetan Plateau","volume":"142","author":"Liu","year":"2020","journal-title":"Theor. Appl. Clim."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"1294","DOI":"10.1016\/j.scitotenv.2019.01.121","article-title":"Freezing\/thawing index variations over the circum-Arctic from 1901 to 2015 and the permafrost extent","volume":"660","author":"Shi","year":"2019","journal-title":"Sci. Total. Environ."},{"key":"ref_39","first-page":"1","article-title":"Mapping the permafrost stability on the Tibetan Plateau for 2005\u20132015","volume":"63","author":"Ran","year":"2020","journal-title":"Sci. China Earth Sci."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"515","DOI":"10.1016\/j.scitotenv.2018.08.369","article-title":"Data-driven mapping of the spatial distribution and potential changes of frozen ground over the Tibetan Plateau","volume":"649","author":"Wang","year":"2019","journal-title":"Sci. Total. Environ."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1016\/j.rse.2017.06.031","article-title":"Google Earth Engine: Planetary-scale geospatial analysis for everyone","volume":"202","author":"Gorelick","year":"2017","journal-title":"Remote Sens. Environ."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"17","DOI":"10.3389\/feart.2017.00017","article-title":"Exploring Google Earth Engine Platform for Big Data Processing: Classification of Multi-Temporal Satellite Imagery for Crop Mapping","volume":"5","author":"Shelestov","year":"2017","journal-title":"Front. Earth Sci."},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Xiong, J., Thenkabail, P., Tilton, J., Gumma, M., Teluguntla, P., Oliphant, A., Congalton, R., Yadav, K., and Gorelick, N. (2017). Nominal 30-m Cropland Extent Map of Continental Africa by Integrating Pixel-Based and Object-Based Algorithms Using Sentinel-2 and Landsat-8 Data on Google Earth Engine. Remote Sens., 9.","DOI":"10.3390\/rs9101065"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"104","DOI":"10.1016\/j.isprsjprs.2017.07.011","article-title":"A mangrove forest map of China in 2015: Analysis of time series Landsat 7\/8 and Sentinel-1A imagery in Google Earth Engine cloud computing platform","volume":"131","author":"Chen","year":"2017","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"360","DOI":"10.1080\/07038992.2020.1802584","article-title":"The Second Generation Canadian Wetland Inventory Map at 10 Meters Resolution Using Google Earth Engine","volume":"46","author":"Mahdianpari","year":"2020","journal-title":"Can. J. Remote Sens."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1016\/j.jag.2014.09.005","article-title":"Multitemporal settlement and population mapping from Landsat using Google Earth Engine","volume":"35","author":"Patel","year":"2015","journal-title":"Int. J. Appl. Earth Obs. Geoinformation"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"11","DOI":"10.1016\/j.accre.2020.05.007","article-title":"Variation of alpine lakes from 1986 to 2019 in the Headwater Area of the Yellow River, Tibetan Plateau using Google Earth Engine","volume":"11","author":"Luo","year":"2020","journal-title":"Adv. Clim. Chang. Res."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"810","DOI":"10.1038\/nclimate3111","article-title":"Earth\u2019s surface water change over the past 30 years","volume":"6","author":"Donchyts","year":"2016","journal-title":"Nat. Clim. Chang."},{"key":"ref_49","doi-asserted-by":"crossref","unstructured":"Wang, C., Jia, M., Chen, N., and Wang, W. (2018). Long-Term Surface Water Dynamics Analysis Based on Landsat Imagery and the Google Earth Engine Platform: A Case Study in the Middle Yangtze River Basin. Remote Sens., 10.","DOI":"10.3390\/rs10101635"},{"key":"ref_50","unstructured":"Lunardini, V.J. (1978, January 10\u201313). Theory of n-factors and correlation of data. Proceedings of the Third International Conference on Permafrost, Edmonton, AB, Canada."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"301","DOI":"10.1002\/(SICI)1099-1530(199610)7:4<301::AID-PPP231>3.0.CO;2-R","article-title":"Permafrost monitoring and detection of climate change","volume":"7","author":"Smith","year":"1996","journal-title":"Permafr. Periglac. Process."},{"key":"ref_52","unstructured":"Lunardini, V.J. (1981). Heat Transfer in Cold Climates, Van Nostrand Reinhold Company."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"252","DOI":"10.1002\/2016GL072033","article-title":"Extensive and drastically different alpine lake changes on Asia\u2019s high plateaus during the past four decades","volume":"44","author":"Zhang","year":"2017","journal-title":"Geophys. Res. Lett."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"574","DOI":"10.1002\/2016JF004018","article-title":"Spatial variability of active layer thickness detected by ground-penetrating radar in the Qilian Mountains, Western China","volume":"122","author":"Cao","year":"2017","journal-title":"J. Geophys. Res. Earth Surf."},{"key":"ref_55","first-page":"19","article-title":"Investigation on permafrost distribution over the upper reaches of the Heihe River in the Qilian Mountains","volume":"35","author":"Wang","year":"2013","journal-title":"J. Glaciol. Geocryol."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.gloplacha.2017.07.011","article-title":"Hydro-thermal processes and thermal offsets of peat soils in the active layer in an alpine permafrost region, NE Qinghai-Tibet plateau","volume":"156","author":"Wang","year":"2017","journal-title":"Glob. Planet. Chang."},{"key":"ref_57","first-page":"63","article-title":"Vegetation characteristics and its distribution of Qilian Mountain region","volume":"36","author":"Chen","year":"1994","journal-title":"Acta Bot. Sin."},{"key":"ref_58","first-page":"827","article-title":"Characteristics of ground temperatures and influencing factors of permafrost development and distribution in the Source Region of Datong River","volume":"30","author":"Li","year":"2011","journal-title":"Prog. Geogr."},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"204","DOI":"10.1016\/j.jhydrol.2016.09.008","article-title":"Long-term change in the depth of seasonally frozen ground and its ecohydrological impacts in the Qilian Mountains, northeastern Tibetan Plateau","volume":"542","author":"Qin","year":"2016","journal-title":"J. Hydrol."},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"396","DOI":"10.1002\/ppp.2056","article-title":"Changing climate and the permafrost environment on the Qinghai\u2013Tibet (Xizang) plateau","volume":"31","author":"Zhao","year":"2020","journal-title":"Permafr. Periglac. Process."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"1051","DOI":"10.1007\/s10346-020-01344-3","article-title":"Acceleration of thaw slump during 1997\u20132017 in the Qilian Mountains of the northern Qinghai-Tibetan plateau","volume":"17","author":"Mu","year":"2020","journal-title":"Landslides"},{"key":"ref_62","first-page":"145","article-title":"Modeling permafrost temperature distribution and analyzing zoning characteristics of permafrost in the source region of the Datong River","volume":"41","author":"Li","year":"2012","journal-title":"J. China Univ. Min. Technol."},{"key":"ref_63","first-page":"357","article-title":"Application of the equivalent-elevation approach to alpine permafrost distribution models in the upper reaches of the Shule River, Qilian Mountains","volume":"33","author":"Li","year":"2011","journal-title":"J. Glaciol. Geocryol."},{"key":"ref_64","unstructured":"Xu, X., Wang, J., and Zhang, L. (2010). Physics of Frozen Soil, Science Publish House."},{"key":"ref_65","doi-asserted-by":"crossref","first-page":"129","DOI":"10.2136\/sh2004.4.0129","article-title":"Soil database of 1:1,000,000 digital soil survey and reference system of the Chinese genetic soil classification system","volume":"45","author":"Shi","year":"2004","journal-title":"Soil Horizons"},{"key":"ref_66","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1002\/ppp.410","article-title":"Climate and the limits of permafrost: A zonal analysis","volume":"13","author":"Smith","year":"2002","journal-title":"Permafr. Periglac. Process."},{"key":"ref_67","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1002\/ppp.615","article-title":"Recent advances in permafrost modelling","volume":"19","author":"Riseborough","year":"2008","journal-title":"Permafr. Periglac. Process."},{"key":"ref_68","doi-asserted-by":"crossref","first-page":"313","DOI":"10.1002\/ppp.3430060404","article-title":"Interannual variations of the thermal regime of the active layer and near-surface permafrost in northern Alaska","volume":"6","author":"Romanovsky","year":"1995","journal-title":"Permafr. Periglac. Process."},{"key":"ref_69","doi-asserted-by":"crossref","first-page":"255","DOI":"10.1657\/AAAR00C-13-306","article-title":"Remote Sensing of the Mean Annual Surface Temperature and Surface Frost Number for Mapping Permafrost in China","volume":"47","author":"Ran","year":"2015","journal-title":"Arctic Antarct. Alp. Res."},{"key":"ref_70","doi-asserted-by":"crossref","unstructured":"Ghafarian Malamiri, H., Rousta, I., Olafsson, H., Zare, H., and Zhang, H. (2018). Gap-Filling of MODIS Time Series Land Surface Temperature (LST) Products Using Singular Spectrum Analysis (SSA). Atmosphere, 9.","DOI":"10.3390\/atmos9090334"},{"key":"ref_71","doi-asserted-by":"crossref","first-page":"2527","DOI":"10.5194\/tc-11-2527-2017","article-title":"A new map of permafrost distribution on the Tibetan Plateau","volume":"11","author":"Zou","year":"2017","journal-title":"Cryosphere"},{"key":"ref_72","doi-asserted-by":"crossref","first-page":"107819","DOI":"10.1016\/j.agrformet.2019.107819","article-title":"Characteristics of ground surface temperature at Chalaping in the Source Area of the Yellow River, northeastern Tibetan Plateau","volume":"281","author":"Luo","year":"2020","journal-title":"Agric. For. Meteorol."},{"key":"ref_73","doi-asserted-by":"crossref","first-page":"10057","DOI":"10.1029\/2018JD028298","article-title":"Characteristics of water-heat exchanges and inconsistent surface temperature changes at an elevational permafrost site on the Qinghai-Tibet Plateau","volume":"123","author":"Luo","year":"2018","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_74","doi-asserted-by":"crossref","first-page":"74","DOI":"10.1016\/j.geoderma.2017.09.037","article-title":"Difference between near-surface air, land surface and ground surface temperatures and their influences on the frozen ground on the Qinghai-Tibet Plateau","volume":"312","author":"Luo","year":"2018","journal-title":"Geoderma"},{"key":"ref_75","doi-asserted-by":"crossref","first-page":"472","DOI":"10.1016\/j.scitotenv.2016.12.155","article-title":"Effects of local factors and climate on permafrost conditions and distribution in Beiluhe basin, Qinghai-Tibet Plateau, China","volume":"581-582","author":"Yin","year":"2017","journal-title":"Sci. Total. Environ."},{"key":"ref_76","doi-asserted-by":"crossref","first-page":"140","DOI":"10.1080\/15230430.2001.12003416","article-title":"The N-factor in Natural Landscapes: Variability of Air and Soil-Surface Temperatures, Kuparuk River Basin, Alaska, U.S.A","volume":"33","author":"Klene","year":"2001","journal-title":"Arctic Antarct. Alp. Res."},{"key":"ref_77","doi-asserted-by":"crossref","first-page":"1033","DOI":"10.1016\/j.scitotenv.2017.09.083","article-title":"Thermal regime of warm-dry permafrost in relation to ground surface temperature in the Source Areas of the Yangtze and Yellow rivers on the Qinghai-Tibet Plateau, SW China","volume":"618","author":"Luo","year":"2018","journal-title":"Sci. Total. Environ."},{"key":"ref_78","first-page":"153","article-title":"Estimation of Vegetation Fraction in the Upper Basin of Miyun Reservoir by Remote Sensing","volume":"26","author":"Li","year":"2004","journal-title":"Resour. Sci."},{"key":"ref_79","doi-asserted-by":"crossref","first-page":"79","DOI":"10.3354\/cr030079","article-title":"Advantages of the mean absolute error (MAE) over the root mean square error (RMSE) in assessing average model performance","volume":"30","author":"Willmott","year":"2005","journal-title":"Clim. Res."},{"key":"ref_80","doi-asserted-by":"crossref","first-page":"221","DOI":"10.5194\/tc-6-221-2012","article-title":"Derivation and analysis of a high-resolution estimate of global permafrost zonation","volume":"6","author":"Gruber","year":"2012","journal-title":"Cryosphere"},{"key":"ref_81","doi-asserted-by":"crossref","first-page":"299","DOI":"10.1016\/j.earscirev.2019.04.023","article-title":"Northern Hemisphere permafrost map based on TTOP modelling for 2000\u20132016 at 1km2 scale","volume":"193","author":"Obu","year":"2019","journal-title":"Earth-Sci. Rev."},{"key":"ref_82","doi-asserted-by":"crossref","first-page":"95","DOI":"10.1016\/j.quascirev.2014.04.030","article-title":"Late Quaternary water depth changes in Hala Lake, northeastern Tibetan Plateau, derived from ostracod assemblages and sediment properties in multiple sediment records","volume":"95","author":"Yan","year":"2014","journal-title":"Quat. Sci. Rev."},{"key":"ref_83","unstructured":"Karunaratne, K., and Burn, C. (2003, January 21\u201325). Freezing n-factors in discontinuous permafrost terrain, Takhini River, Yukon Territory, Canada. Proceedings of the 8th International Conference on Permafrost, Zurich, Switzerland."},{"key":"ref_84","first-page":"281","article-title":"Spatiotemporal variability of permafrsot degradation on the Qinghai-Tibet Plateau","volume":"3","author":"Jin","year":"2011","journal-title":"Sci. Cold Arid Reg."},{"key":"ref_85","unstructured":"French, H.M. (2018). The Periglacial Environment, John Wiley & Sons Ltd. [4th ed.]."},{"key":"ref_86","first-page":"817","article-title":"Permafrost changes in the northern limit of permafrost on the Qinghai-Tibet Plateau in the last 30 years","volume":"58","author":"Nan","year":"2003","journal-title":"Acta Geogr. Sin."},{"key":"ref_87","doi-asserted-by":"crossref","unstructured":"Harris, S.A., Brouchkov, A., and Guodong, C. (2018). Geocryology: An. Introduction to Frozen Ground, CRC Press. [1st ed.].","DOI":"10.4324\/9781315166988"},{"key":"ref_88","first-page":"184","article-title":"Permafrost distribution in the Dabanshan Pass Section of Ning-Zhang highway in Eastern Qilian Mountains","volume":"17","author":"Wang","year":"1995","journal-title":"J. Glaciol. Geocryol."},{"key":"ref_89","doi-asserted-by":"crossref","first-page":"83","DOI":"10.1002\/ppp.3430030205","article-title":"Distribution of mountain permafrost and climate","volume":"3","author":"Cheng","year":"1992","journal-title":"Permafr. Periglac. Process."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/13\/1\/149\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T05:07:08Z","timestamp":1760159228000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/13\/1\/149"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,1,5]]},"references-count":89,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2021,1]]}},"alternative-id":["rs13010149"],"URL":"https:\/\/doi.org\/10.3390\/rs13010149","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,1,5]]}}}