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Thermal regimes and degradation modes of permafrost along the Qinghai-Tibet Highway

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Science China Earth Sciences 2006年第11期49卷 1170-1183页

作者： jin huijun ZHAO Lin WANG Shaoling jin Rui State Key Laboratory of Frozen Soils Engineering and Cryosphere Station of the Qinghai-Tibet Plateau Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of SciencesLanzhou 730000 China

Permafrost on the Qinghai-Tibet Plateau (QTP) is widespread, thin, and thermally unstable. Under a warming climate during the past few decades, it has been degrading extensively with generally rising ground temperatures, the deepening of the maximum summer thaw, and with lessening of the winter frost penetration. The permafrost has degraded downward, upward and laterally. Permafrost has thinned or, in some areas, has totally disappeared. The modes of permafrost degradation have great significance in geocryology, in cold regions engineering and in cold regions environmental management. Permafrost in the interior of the QTP is well represented along the Qing-hai-Tibet Highway (QTH), which crosses the Plateau through north to south and traverses 560 km of permafrost-impacted ground. Horizontally, the degradation of permafrost occurs more visibly in the sporadic permafrost zone in the vicinity of the lower limit of permafrost (LLP), along the margins of taliks, and around permafrost islands. Downward degradation develops when the maximum depth of seasonal thaw exceeds the maximum depth of seasonal frost, and it generally results in the formation of a layered talik disconnecting the permafrost from the seasonal frost layer. The downward degrada- tion is divided into four stages: 1) initial degradation, 2) accelerated degradation, 3) layered talik and 4) finally the conversion of permafrost to seasonally frozen ground (SFG). The upward degradation occurs when the geothermal gradient in permafrost drops to less than the geothermal gradients in the underlying thawed soil layers. Three types of permafrost temperature curves (stable, degrading, and phase-changing transitory permafrost) illustrate these modes. Although strong differentiations in local conditions and permafrost types exist, the various combinations of the three degradation modes will ultimately transform permafrost into SFG. Along the QTH, the downward degradation has been proceeding at annual rates of 6 to 25

关键词： QTP QTH permafrost ground temperatures degradation modes geothermal gradients.

Spatiotemporal characteristics of freezing and thawing of the active layer in the source areas of the Yellow River(SAYR)

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Chinese Science Bulletin 2014年第14期59卷 3034-3045页

作者： Dongliang Luo huijun jin Lanzhi Lü Qingbai Wu State Key Laboratory of Frozen Soils Engineering Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of Sciences

Based on the analysis of data on temperatures and moisture of soils in the active layer at four different permafrost sites in the source areas of the Yellow River(SAYR)in 2010–2012,the freeze–thaw processes of soils in the active layer were compared and contrasted for understanding the spatiotemporal *** the four studied sites,the thickness and mean annual temperature of permafrost are *** temperatures at the top of permafrost(TTOP),i.e.,the maximum depth(s)of seasonal frost and/or thaw penetration,are-1.9°C at the Chalaping site(CLP),-0.9°C at the site on the southern bank of the Zhaling Lake(ZLH),-0.4°C at the Maduo Town site(MDX),and 1.1°C at the site on the northern bank of the Eling Lake(ELH).Differences in the mean annual ground temperature of permafrost and TTOPs may be responsible for the differentiations in the freeze–thaw processes of soils in the active *** rising TTOPs,the ground thawing started earlier:CLP in early June,ZLH in late May,MDX in early May,and ELH in mid-April,while the freezing began later:CLP in early October,ZLH in early to midOctober,MDX in mid-October,and ELH in the mid-to late *** increasing TTOPs,the freeze-up periods for permafrost sites were shortened:202 days at CLP,130 days at ZLH,100 days at MDX,and the period of complete thaw was 89 days at *** the CLP and ZLH sites,the two-directional ground freezing(downwards from ground surfaces and upwards from the permafrost table)and thawing finished in the same year,but the ground freezing at the MDX continued to the end of the nextJanuary,with very slow freezing rates in the *** the ELH site,ground freezing kept on until early May when thawing began on the surface,and upward and downward thawing became increasingly stable in late June to early *** each site,with rising TTOPs,the downward freezing accelerated in comparison with the upward freezing,and with an increasing proportion of downward frozen depth,and with the larger ratios of freezin

关键词：冷冻速率黄河源区解冻期活性层时空特性多年冻土冻融过程冻结深度

Synergetic variations of active layer soil water and salt in a permafrost-affected meadow in the headwater area of the Yellow River,northeastern Qinghai-Tibet plateau

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International Soil and Water Conservation Research 2022年第2期10卷 284-292页

作者： Qingfeng Wang huijun jin Ziqiang Yuan Chengsong Yang State Key Laboratory of Frozen Soil Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of Sciences(CAS)320 Donggang West RoadLanzhouGansu Province730000China School of Civil Engineering Northeast-China Observatory and Research-Station of Permafrost Geo-Environment(Ministry of Education)Institute of Cold-Regions Engineering and EnvironmentNortheast Forestry University26 Hexing RoadHarbinHeilongjiang Province150040China State Key Laboratory of Grassland Agro-Ecosystem Institute of Arid Agro-EcologySchool of Life SciencesLanzhou UniversityLanzhouGansu730000China

The coupling effects and mechanisms of water,heat,and salt in frozen soils are considered to be one of the core scientific issues in frozen soil *** study was based on in situ observation data of active layer soil volumetric water content(VWC),temperature,and bulk electrical conductivity(EC)obtained at an alpine meadow site from October 2016 to November *** site is located in the headwater area of the Yellow River(HAYR).We analyzed the synergetic variations of active layer soil VWC,temperature,and bulk EC during the freeze and thaw processes and discussed the underlying *** the thaw process occurred from 10 to 80 cm depths,the VWC and bulk EC at a 10 cm depth showed syn-chronous high-frequency fluctuations and both increased *** linear decreasing rate of the VWC(bulk EC)at an 80 cm depth in the freeze depths between 0 and 40 cm was 2(1.6e2.3)times that of the VWC(bulk EC)at an 80 cm depth in the freeze depths occurring 0e10 *** soil temperature decreased in the frozen layer,unfrozen water content(bulk EC)decreased nonlinearly along with the absolute value of soil temperature(|T|),following a power(logarithmic)*** study provided data that partly elucidate the interactions among permafrost,meadow,and ecohydrological processes in the ***,our results can be used as a scientific basis for decision making on the protection and restoration of alpine grasslands,as well as for soil salinization studies.

关键词： Freeze and thaw process Active layer Soil water Bulk electrical conductivity Yellow river

Symbiosis of Marshes and Permafrost in Da and Xiao Hinggan Mountains in Northeastern China

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Chinese Geographical Science 2008年第1期18卷 62-69页

作者： jin huijun SUN Guangyou YU Shaopeng jin Rui HE Ruixia State Key Laboratory of Frozen Soils Engineering Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China Northeast Institute of Geography and Agroecology Chinese Academy of Sciences Changchun 130012 China Department of Geography Harbin College Harbin 150086 China

Recently, the degradation of permafrost and marsh environments in the Da and Xiao Hinggan Mountains has become a great concern as more human activities and pronounced climate warming were observed during the past 30 years and projected for the near future. The distr/bution patterns and development mechanisms of the permafrost and marshes have been examined both in theories and in field observations, in order to better understand the symbiosis of permafrost and marshes. The permafrost and marshes in the Da and Xiao Hinggan Mountains display discernible zonations in latitude and elevation. The marsh vegetation canopy, litter and peat soil have good thermal insulation properties for the underlying permafrost, resulting in a thermal offset of 3 ℃ to 4℃ and subsequently suppressing soil temperature. In addition, the much higher thermal conductivity of frozen and ice-rich peat in the active layer is conducive to the development or in favor of the protection of permafrost due to the semi-conductor properties of the soils overlying the permafrost. On the other hand, because permafrost is almost impervious, the osmosis of water in marsh soils can be effectively reduced, timely providing water supplies for helophytes growth or germination in spring. In the Da and Xiao Hinggan Mountains, the permafrost degradation has been accelerating due to the marked climate warming, ever increasing human activities, and the resultant eco-environmental changes. Since the permafrost and marsh environments are symbiotic and interdependent, they need to be managed or protected in a well-coordinated and integrated way.

关键词： marsh permafrost symbiosis thermal offset active layer Da and Xiao Hinggan Mountains

Distribution and changes of active layer thickness(ALT) and soil temperature(TTOP) in the source area of the Yellow River using the GIPL model

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Science China Earth Sciences 2014年第8期57卷 1834-1845页

作者： LUO DongLiang jin huijun Sergei MARCHENKO Vladimir ROMANOVSKY State Key Laboratory of Frozen Soils Engineering Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of Sciences Geophysical Institute University of Alaska FairbanksFairbanks Alaska 99775 USA

Active layer thickness（ALT） is critical to the understanding of the surface energy balance, hydrological cycles, plant growth, and cold region engineering projects in permafrost regions. The temperature at the bottom of the active layer, a boundary layer between the equilibrium thermal state（in permafrost below） and transient thermal state（in the atmosphere and surface canopies above）, is an important parameter to reflect the existence and thermal stability of permafrost. In this study, the Geophysical Institute Permafrost Model（GIPL） was used to model the spatial distribution of and changes in ALT and soil temperature in the Source Area of the Yellow River（SAYR）, where continuous, discontinuous, and sporadic permafrost coexists with seasonally frozen ground. Monthly air temperatures downscaled from the CRU TS3.0 datasets, monthly snow depth derived from the passive microwave remote-sensing data SMMR and SSM/I, and vegetation patterns and soil properties at scale of 1：1000000 were used as input data after modified with GIS techniques. The model validation was carried out carefully with in-situ ALT in the SAYR interpolated from the field-measured soil temperature data. The results of the model indicate that the average ALT in the SAYR has significantly increased from 1.8 m in 1980 to 2.4 m in 2006 at an average rate of 2.2 cm yr–1. The mean annual temperature at the bottom of the active layer, or temperature at the top of permafrost（TTOP） rose substantially from –1.1°C in 1980 to –0.6°C in 2006 at an average rate of 0.018°C yr–1. The increasing rate of the ALT and TTOP has accelerated since 2000. Regional warming and degradation of permafrost has also occurred, and the changes in the areal extent of regions with a sub-zero TTOP shrank from 2.4×104 to 2.2×104 km2 at an average rate of 74 km2 yr–1. Changes of ALT and temperature have adversely affected the environmental stability in the SAYR.

关键词： GIPL model active layer thickness TTOP degradation of permafrost

Dissolved organic carbon in permafrost regions: A review

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Science China Earth Sciences 2019年第2期62卷 349-364页

作者： Qiang MA huijun jin Congrong YU Victor F.BENSE State Key Laboratory of Frozen Soils Engineering Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences College of Resources and Environment University of Chinese Academy of Sciences School of Civil Engineering Harbin Institute of Technology State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University Hydrology and Quantitative Water Management Group Department of Environmental Sciences Wageningen University

A large quantity of organic carbon(C) is stored in northern and elevational permafrost regions. A portion of this large terrestrial organic C pool will be transferred by water into soil solution(～0.4 Pg C yr^(-1))(1 Pg=10^(15) g), rivers (～0.06 Pg C yr^(-1)),wetlands, lakes, and oceans. The lateral transport of dissolved organic carbon(DOC) is the primary pathway, impacting river biogeochemistry and ecosystems. However, climate warming will substantially alter the lateral C shifts in permafrost ***, permafrost, precipitation, soil humidity and temperature, and microbial activities, among many other environmental factors, will shift substantially under a warming climate. It remains uncertain as to what extent the lateral C cycle is responding,and will respond, to climate change. This paper reviews recent studies on terrestrial origins of DOC, biodegradability, transfer pathways, and modelling, and on how to forecast of DOC fluxes in permafrost regions under a warming climate, as well as the potential anthropogenic impacts on DOC in permafrost regions. It is concluded that:(1) surface organic layer, permafrost soils,and vegetation leachates are the main DOC sources, with about 4.72 Pg C DOC stored in the topsoil at depths of 0–1 m in permafrost regions;(2) in-stream DOC concentrations vary spatially and temporally to a relatively small extent (1–60 mg C L^(-1)) and annual export varies from 0.1–10 g C m^(-2) yr^(-1);(3) biodegradability of DOC from the thawing permafrost can be as high as 71%, with a median at 52%;(4) DOC flux is controlled by multiple factors, mainly including vegetation, soil properties,permafrost occurrence, river discharge and other related environmental factors, and(5) many statistical and process-based models have been developed, but model predictions are inconsistent with observational results largely dependent on the individual watershed characteristics and future discharge trends. Thus, it is still difficult to predict how futu

关键词： Dissolved organic carbon (DOC) Aquatic ecosystem Carbon biodegradability DOC export Permafrost degradation

Climate warming over 1961–2019 and impacts on permafrost zonation in Northeast China

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Journal of Forestry Research 2022年第3期33卷 767-788页

作者： Xiaoying Li huijun jin Long Sun Hongwei Wang Ruixia He Yadong Huang Xiaoli Chang Key Laboratory of Sustainable Forest Ecosystem Management Ministry of EducationSchool of ForestryNortheast Forestry UniversityHarbin150040People’s Republic of China School of Civil Engineering Northeast China Observatory and Research Station of Permafrost Geo-Environment-Ministry of EducationInstitute of Cold-Regions Engineering Science and TechnologyNortheast Forestry UniversityHarbin150040People’s Republic of China Da-Xing’anling Observatory and Research Station of Permafrost Engineering and Environment and State Key Laboratory of Frozen Soils Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou730000People’s Republic of China School of Resource and Environmental and Safety Engineering Hunan University of Science and TechnologyXiangtanHunan411202People’s Republic of China

In boreal forest ecosystems, permafrost and forest types are mutually interdependent;permafrost degradation impacts forest ecosystem structure and functions. The Xing’an permafrost in Northeast China is on the southern margin of the Eastern Asia latitudinal permafrost body. Under a warming climate, permafrost undergoes rapid and extensive degradation. In this study, the frost-number (Fn) model based on air temperatures and ground surface temperatures was used to predict the distribution of the Xing’an permafrost, and, temporal and spatial changes in air and ground-surface temperatures from 1961 to 2019 are analyzed. The results show that Northeast China has experienced a rapid and substantial climate warming over the past 60 years. The rises in mean annual air and mean annual ground-surface temperatures were higher in permafrost zones than those in the seasonal frost zone. The frost numbers of air and ground-surface temperatures were calculated for determining the southern limit of latitudinal permafrost and for permafrost zonation. The southern limits of discontinuous permafrost, sporadic permafrost, and latitudinal permafrost moved northward significantly. According to the air-temperature frost-number criteria for permafrost zoning, compared with that in the 1960s, the extent of Xing’an permafrost in Northeast China had decreased by 40.6% by the 2010s. With an average rate of increase in mean annual air temperatures at 0.03 ℃ a^(−1), the extent of permafrost in Northeast China will decrease to 26.42 × 10^(4) by 2020, 14.69 × 10^(4) by 2040 and to 11.24 × 10^(4) km^(2) by 2050. According to the ground-surface temperature frost-number criteria, the southern limit of latitudinal permafrost was at the 0.463. From the 1960s to the 2010s, the extent of latitudinal permafrost declined significantly. Due to the nature of the ecosystem-protected Xing’an-Baikal permafrost, management and protection (e.g., more prudent and effective forest fire management and proper logging

关键词： Climate warming Permafrost zonation Southern limit of latitudinal permafrost Regional differentiation Mean annual air temperature Mean annual ground surface temperature

Possible controlling factors in the development of seasonal sand wedges on the Ordos Plateau,North China

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Research in Cold and Arid Regions 2021年第2期13卷 167-176页

作者： Hugh MFrenchψ Jef Vandenberghe huijun jin RuiXia He Departments of Geography and Earth Sciences University of OttawaOntarioCanadaDepartment of GeographyUniversity of VictoriaBritish ColumbiaCanada Institute of Earth Sciences Vrije Universiteit AmsterdamThe Netherlands School of Civil Engineering Institute of Cold-Regions EngineeringScience and TechnologyNortheast-China Observatory and Research-Station of Permafrost Geo-Environment-Ministry of EducationNortheast Forestry UniversityHarbinHeilongjiang150040China State Key Laboratory of Frozen Soils Engineering and Northwest Institute of Eco-Environment and Resources Chinese Academy of SciencesLanzhouGansu 730000China

Wedge-like structures filled with silty sand penetrate Quaternary fluvial and aeolian sediments and, in places, Tertiary bedrock on the Ordos Plateau, North China. The wedges reflect thermal contraction cracking of either permafrost or seasonal frost during the Late Pleistocene and early Holocene. Wedges of about 1 m in depth form polygonal nets of 2-3 m in diameter(type B). They contrast with wedges of 3-4 m in depth that form polygons of 10-15 m in diameter(type A).This review focuses upon the highly variable size of the inferred polygon nets and discusses the problem of differentiating between seasonally and perennially frozen ground, or between seasonal frost and permafrost.

关键词： frozen ground sand-wedge casts frost fissures thermal contraction cracking seasonal frost cracking desiccation cracking

Trend and Characteristics of Variation on the Runoffof the Upper Yellow River above Tangnag

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中国沙漠 2000年第3期20卷 42-46页

作者： Lan Yongchao jin huijun Kang Ersi Ma Quanjie 中科院寒区与旱区环境与工程所甘肃兰州 730000 Hydrology and Water Resources Bureau of the Upper Yellow Riv 甘肃兰州 730030

根据唐乃亥等有关台站的水文气象观测资料 ,对黄河上游唐乃亥以上流域的径流特征及演变规律进行了分析探讨 ,并在此基础上利用灰色拓扑、混合门限自回归及周期外延——逐步回归等数学模型对其未来的变化趋势进行了预测。结果表明 ,黄河... 详细信息

根据唐乃亥等有关台站的水文气象观测资料 ,对黄河上游唐乃亥以上流域的径流特征及演变规律进行了分析探讨 ,并在此基础上利用灰色拓扑、混合门限自回归及周期外延——逐步回归等数学模型对其未来的变化趋势进行了预测。结果表明 ,黄河上游唐乃亥以上流域径流目前正处于一个枯水段的底部 ,并且从现在起的今后若干年里将呈现一个波动状上升的变化趋势

关键词：径流特征演变规律周期分析变化规律趋势预测