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Highway Roadway Stability Influenced by Warm Permafrost and Seasonal Frost Action:A Case Study from Glennallen,Alaska,USA 被引量:6
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作者 Max C.Brewer 《Research in Cold and Arid Regions》 2008年第1期26-41,共16页
Ground temperatures from four of the seven extensively studied highway cross-sections near Gulkana/Glennallen,Alaska during 1954;962,were chosen to better understand the impacts of highway construction on warm permafr... Ground temperatures from four of the seven extensively studied highway cross-sections near Gulkana/Glennallen,Alaska during 1954;962,were chosen to better understand the impacts of highway construction on warm permafrost.Both the thawing of permafrost and seasonal frost action impacted on road surface stability for about 6 years until the maximum summer thaw reached about 3 m in depth.Seasonal frost action caused most of the ensuing stability problems.Unusually warm summers and the lengths of time required to re-freeze the active layer were far more important than the average annual air temperatures in determining the temperatures of the underlying shallow permafrost,or the development of taliks.The hypothesized climate warming would slightly and gradually deepen the active layer and the developed under-lying talik,but its effect would be obscured by unusually warm summers,by warmer than usual winters,and by the vari-able lengths of time of the zero curtains.At least one period of climate mini-cooling in the deeper permafrost during the early 20th century was noted. 展开更多
关键词 warm permafrost active layer seasonal frost action zero curtain talik ROADWAY climate warming
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Dynamic response of wind turbine towers in warm permafrost
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作者 Benjamin Still ZhaoHui (Joey) Yang +1 位作者 Simon Evans FuJun Niu 《Research in Cold and Arid Regions》 CSCD 2014年第5期423-427,共5页
Wind is a great source of renewable energy in western Alaska.Consistent winds blow across the barren tundra underlain by warm permafrost in the winter season,when the energy demand is the highest.Foundation engineerin... Wind is a great source of renewable energy in western Alaska.Consistent winds blow across the barren tundra underlain by warm permafrost in the winter season,when the energy demand is the highest.Foundation engineering in warm permafrost has always been a challenge in wind energy development.Degrading warm permafrost poses engineering issues to design,construction,and operation of wind turbines.This paper describes the foundation design of a wind turbine built in western Alaska.It presents a system for response monitoring and load assessment,and data collected from September 2013 to March 2014.The dynamic properties are assessed based on the monitoring data,and seasonal changes in the dynamic properties of the turbine tower-foundation system and likely resonance between the spinning blades and the tower structure are discussed.These analyses of a wind turbine in warm permafrost are valuable for designing or retrofitting of foundations in warm permafrost. 展开更多
关键词 wind turbine vibration field monitoring warm permafrost
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Degradation of warm permafrost and talik formation on the Qinghai-Tibet Plateau in 2006-2021 被引量:1
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作者 Qi-Hang MEI Ji CHEN +5 位作者 You-Qian LIU Shou-Hong ZHANG Jing-Yi ZHAO Tian-Chun DONG Jun-Cheng WANG Yao-Jun ZHAO 《Advances in Climate Change Research》 SCIE CSCD 2024年第2期275-284,共10页
Permafrost is degrading globally,particularly those with low thermal stability on the Qinghai-Tibet Plateau,owing to climate change.However,the inadequacy of direct research on permafrost degradation based on in-situ ... Permafrost is degrading globally,particularly those with low thermal stability on the Qinghai-Tibet Plateau,owing to climate change.However,the inadequacy of direct research on permafrost degradation based on in-situ monitoring limits the prediction of permafrost degradation and engineering practices.This study explored the processes and modes of permafrost degradation into talik by analyzing ground temperature data from five points in the hinterland of the Qinghai-Tibet Plateau from 2006 to 2021.The results showed that the degradation of the warm permafrost layer with a geothermal gradient of zero occurred simultaneously in the top and bottom directions.The rate of permafrost degradation from the top down and bottom up increase during the degradation process,but the increase of the former is more drastic after the formation of thawed interlayer.Additionally,the construction of the Qinghai-Tibet Railway changed the degradation modes of the permafrost in adjacent natural sites through horizontal heat transfer,particularly after through talik formation under the embankment.The findings suggest that taking countermeasures before or immediately after forming thawed interlayer is more effective.When evaluating the thermal impact of projects in warm permafrost regions,special attention should be given to the horizontal heat transfer process that may result from the formation of a through talik. 展开更多
关键词 warm permafrost DEGRADATION Talik Qinghai-Tibet Plateau Climate change
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Full-scale site evaluation of ventilation expressway embankments underlain by warm permafrost along the Gonghe−Yushu Expressway
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作者 Shuangjie WANG Qi ZHANG +4 位作者 Yuanhong DONG Kun YUAN Binhua HU Huilong ZHAO Nanlu ZHAO 《Frontiers of Structural and Civil Engineering》 SCIE EI CSCD 2023年第7期1047-1059,共13页
Ventilation embankments,including those with forced ventilation,natural ventilation,and combination of these,were adopted for the construction of the Gonghe−Yushu Expressway in warm permafrost areas.To evaluate the ac... Ventilation embankments,including those with forced ventilation,natural ventilation,and combination of these,were adopted for the construction of the Gonghe−Yushu Expressway in warm permafrost areas.To evaluate the actual thermal performance of ventilation embankment in the Qinghai−Tibet Plateau,four types of ventilation embankments were selected as objects,and their long-term thermal characteristics were analyzed based on monitoring data.It was found that:1)under the strong scale effect of a wide embankment,the crushed-rock embankment(CRE)was warming up and the permafrost table was declining year by year.Meanwhile,the combined ventilated slab and CRE and ventilated ducts embankment can effectively decrease the ground temperature and raise permafrost table in the year with a colder winter;2)transverse temperature difference caused by the shady–sunny slope effect existed in all the four embankments.However,it was weakened by the combined ventilated slab and CRE and the ventilated ducts embankment due to their stronger cooling effect;and 3)the pre-existing embankment had a remarkable thermal disturbance to the adjacent newly-built embankment,so a reasonable embankment spacing should be considered in practical engineering.These findings would provide a reference for construction of expressway embankments in permafrost regions. 展开更多
关键词 warm permafrost EXPRESSWAY ventilation embankments temperature field
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Field observations of the thermal stability of permafrost under buildings with an underfloor open ventilation space and pile foundations in warm permafrost at high altitudes
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作者 Xin HOU Ji CHEN +5 位作者 Yu SHENG Peng-Fei RUI You-Qian LIU Shou-Hong ZHANG Tian-Chun DONG Jia-Wei GAO 《Advances in Climate Change Research》 SCIE CSCD 2023年第2期267-275,共9页
Pile foundations combined with ventilation spaces under floors are the most common method in buildings over permafrost.The safety and stability of buildings are closely related to the temperature of permafrost.However... Pile foundations combined with ventilation spaces under floors are the most common method in buildings over permafrost.The safety and stability of buildings are closely related to the temperature of permafrost.However,there are limitations of understanding on this method in the high-altitude,warm(>−1℃)permafrost areas on the Qinghai–Tibet Plateau.In this study,the thermal stability of permafrost foundation soils under buildings with an underfloor open ventilation space and pile foundations in warm permafrost at high altitudes was studied through field observations of ground and air temperatures,wind speed,net radiation from 2017 to 2021.The results indicated that the open ventilation space exerted an effective cooling effect on the underlying permafrost and pile foundations from March to October,while a thermal insulation effect was observed from November to February of the following year,but overall,the cooling effect dominated;the cooling effect of open ventilation spaces differed spatially.The permafrost temperature on the south-facing side was higher than that on the north-facing side,and those on the east and west sides were higher than that directly under the open ventilation space of the building.This study also demonstrated that radiation shielded by the building was a main factor of the cooling effect of open ventilation spaces,and the cooling effect of open ventilation spaces could accelerate the back-freezing of the cast-in-place(CIP)pile foundations.This structure could effectively maintain the frozen state of the underlying warm permafrost at high elevations on the interior Qinghai–Tibet Plateau. 展开更多
关键词 warm permafrost INFRASTRUCTURE Open ventilation space Pile foundation Cooling effect
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Permafrost warming along the Mo'he-Jiagedaqi section of the China-Russia crude oil pipeline 被引量:8
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作者 WANG Fei LI Guo-yu +4 位作者 MA Wei MAO Yun-cheng MU Yan-hu SERBAN Mihaela CAI Yong-jun 《Journal of Mountain Science》 SCIE CSCD 2019年第2期285-295,共11页
The permafrost along the China-Russia Crude Oil Pipeline(CRCOP) is degrading since the pipeline operation in 2011. Heat dissipated from the pipeline, climate warming and anthropogenic activities leads to permafrost wa... The permafrost along the China-Russia Crude Oil Pipeline(CRCOP) is degrading since the pipeline operation in 2011. Heat dissipated from the pipeline, climate warming and anthropogenic activities leads to permafrost warming. The processes of permafrost warming along the CRCOP were studied based on the monitoring of air and soil temperatures, and electrical resistivity tomography(ERT) surveys. Results show that:(1) the mean annual air temperature(MAAT) in permafrost regions along the CRCOP increased with a rate of 0.21°C/10a–0.40°C/10 a during the past five decades;(2) the mean annual ground temperature(MAGT, at-15 m depth) of undisturbed permafrost increased by 0.2°C and the natural permafrost table remained unchanged due to the zero-curtain effect;(3) permafrost surrounding the uninsulated pipeline right-of-way warmed significantly compared with that in a natural site. During 2012–2017, the MAGT and the artificial permafrost table, 2 m away from the pipeline centerline, increased at rates of 0.063°C/a and 1.0 m/a. The thaw bulb developed around the pipe and exhibits a faster lateral expansion;(4) 80-mm-thick insulation could reduce the heat exchange between the pipeline and underlying permafrost and then keep the permafrost and pipe stable. The MAGT and the artificial permafrost table, 4.8 m away from the center line of the pipeline, increased by 0.3°C/a and 0.43 m/a, respectively. Due to the heat disturbance caused by warm oil, the degradation of wetland, controlled burn each autumn and climate warming, the permafrost extent reduced and warmed significantly along the CRCOP route. Field observations provide basic data to clarify the interactions between CRCOP and permafrost degradation and environmental effects in the context of climate change. 展开更多
关键词 permafrost warmING China-Russia CRUDE Oil Pipeline Air TEMPERATURE Soil TEMPERATURE Climate warmING
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Discussion on possibilities of taking ground ice in permafrost as water sources on the Qinghai-Tibet Plateau during climate warming 被引量:1
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作者 JiChun Wu,Yu Sheng,QingBai Wu,Jing Li,XiuMin Zhang State Key Laboratory of Frozen Soil Engineering,Cold and Arid Regions Environmental Engineering Research Institute,Chinese Academy of Sciences,Lanzhou,Gansu 730000,China. 《Research in Cold and Arid Regions》 2009年第4期322-328,共7页
Large amounts of ground ice are born with permafrost on the Qinghai-Tibet Plateau.Degradation of permafrost resulted from the climate warming will inevitably lead to melting of ground ice.The water released from the m... Large amounts of ground ice are born with permafrost on the Qinghai-Tibet Plateau.Degradation of permafrost resulted from the climate warming will inevitably lead to melting of ground ice.The water released from the melting ground ice enters hydrologic cycles at various levels,and changes regional hydrologic regimes to various degrees.Due to difficulties in monitoring the perma-frost-degradation-release-water process,direct and reliable evidence is few.The accumulative effect of releasing water,however,is remarkable in the macro-scale hydrologic process.On the basis of the monitoring results of water-levels changes in some lakes on the Qinghai-Tibet Plateau,and combined with the previous results of the hydrologic changing trends at the regional scale,the authors preliminarily discussed the possibilities of the degrading permafrost on the Qinghai-Tibet Plateau as a potential water source during climate warming. 展开更多
关键词 climate warming thawing permafrost melting ground ice potential water source
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Application of a concrete thermal pile in cooling the warming permafrost under climate change 被引量:1
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作者 Yun-Hu SHANG Fu-Jun NIU +2 位作者 Guo-Yu LI Jian-Hong FANG Ze-Yong GAO 《Advances in Climate Change Research》 SCIE CSCD 2024年第1期170-183,共14页
Permafrost degradation caused by climate warming is posing a serious threat to the stability of cast-in-place pile foundations in warm permafrost regions.Ambient cold energy can be effectively utilized by two-phase cl... Permafrost degradation caused by climate warming is posing a serious threat to the stability of cast-in-place pile foundations in warm permafrost regions.Ambient cold energy can be effectively utilized by two-phase closed thermosyphons(TPCTs)to cool the permafrost.Therefore,we installed TPCTs in a cast-in-place pile foundation to create a unique structure called a thermal pile,which effectively utilizes the TPCTs to regulate ground temperature.And we conducted a case study and numerical simulation to exhibit the cooling performance,and optimize the structure of the thermal pile.The purpose of this study is to promote the application of thermal piles in unstable permafrost regions.Based on the findings,the thermal pile operated for approximately 53%of the entire year and effectively reduced the deep ground temperature at a rate of at least-0.1℃per year.Additionally,it successfully raised the permafrost table that is 0.35 m shallower than the natural ground level.These characteristics prove highly beneficial in mitigating the adverse effects of permafrost degradation and enhancing infrastructure safety.Expanding the length of the condenser section and the diameter of the TPCT in a suitable manner can effectively enhance the cooling capability of the thermal pile and ensure the long-term mechanical stability of the pile foundation even under climate warming. 展开更多
关键词 Heat transfer Cold energy warm permafrost Two-phase closed thermosyphons Cast-in-place pile foundation
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青藏高原降雨增加和气温升高对多年冻土水热动态贡献研究
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作者 张明礼 雷兵兵 +3 位作者 周凤玺 侯彦东 冯微 周志雄 《岩土力学》 EI CAS CSCD 北大核心 2024年第7期2140-2152,共13页
在人类活动和全球气候变化驱动下,青藏高原气候整体呈现暖湿化变化趋势,由此引发的多年冻土活动层水热变化对寒区生态环境和寒区工程稳定性产生显著影响。目前,温度升高对多年冻土的影响机制较为明确,但降雨增加、降雨增加与气温升高共... 在人类活动和全球气候变化驱动下,青藏高原气候整体呈现暖湿化变化趋势,由此引发的多年冻土活动层水热变化对寒区生态环境和寒区工程稳定性产生显著影响。目前,温度升高对多年冻土的影响机制较为明确,但降雨增加、降雨增加与气温升高共同作用下的多年冻土水热响应过程和机制尚不明确。在考虑雨水感热作用的地表能水平衡-冻土水热耦合模型的基础上,对比研究气温升高、降雨增加单一作用及其共同作用对活动层水热影响机制。结果表明:相比气温升高和降雨增加单一作用,暖湿化复合作用导致地表净辐射通量和蒸发潜热通量增长显著,地表感热降低更加明显,雨水感热影响较小,地表土壤热通量呈增加趋势;暖湿化复合作用下温度梯度液态水通量增长显著,基质势梯度液态水通量在浅层增幅也大于单独升温作用,但小于单一降雨增加作用,暖湿化导致暖季土壤含水率增幅小于单独降雨作用;暖湿化作用下活动层热传导通量在冷季增加显著且增幅小于单独升温作用,而液态水对流传热在暖季增加明显且增幅小于单独湿化作用;降雨增加促使土体暖季降温显著,暖湿化与单一气温升高均导致土体在冷季升温效果高于暖季;气温升高1.0℃引起多年冻土上限下移10cm,降雨增加100 mm促使上限抬升8 cm,暖湿化共同作用导致冻土上限下移6 cm;在暖湿化作用下,降雨增加对冻土降温作用较小,气温升高对冻土的升温效应仍占据主导。 展开更多
关键词 多年冻土 暖湿化 地表能量平衡 水热变化 青藏高原
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Characteristics of permafrost degradation in Northeast China and its ecological effects: A review 被引量:1
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作者 ShanShan Chen ShuYing Zang Li Sun 《Research in Cold and Arid Regions》 CSCD 2020年第1期1-11,共11页
Latitudinal permafrost in Northern Northeast(NNE)China is located in the southern margin of the Eurasian continent,and is very sensitive to climatic and environmental change.Numerical simulations indicate that air tem... Latitudinal permafrost in Northern Northeast(NNE)China is located in the southern margin of the Eurasian continent,and is very sensitive to climatic and environmental change.Numerical simulations indicate that air temperature in the permafrost regions of Northeast China has been on the rise since the 1950s,and will keep rising in the 21st century,leading to extensive degradation of permafrost.Permafrost degradation in NNE China has its own characteristics,such as northward shifts in the shape of a"W"for the permafrost southern boundary(SLP),discontinuous permafrost degradation into islandlike frozen soil,and gradually disappearing island permafrost.Permafrost degradation leads to deterioration of the ecological environment in cold regions.As a result,the belt of larch forests dominated by Larix gmelinii has shifted northwards and wetland areas with symbiotic relationships with permafrost have decreased significantly.With rapid retreat and thinning of permafrost and vegetation change,the CO2 and CH4 flux increases with mean air temperature from continuous to sporadic permafrost areas as a result of activity of methanogen enhancement,positively feeding back to climate warming.This paper reviews the features of permafrost degradation,the effects of permafrost degradation on wetland and forest ecosystem structure and function,and greenhouse gas emissions on latitudinal permafrost in NNE China.We also put forward critical questions about the aforementioned effects,including:(1)establish long-term permafrost observation systems to evaluate the distribution of permafrost and SLP change,in order to study the feedback of permafrost to climate change;(2)carry out research about the effects of permafrost degradation on the wetland ecosystem and the response of Xing'an larch to global change,and predict ecosystem dynamics in permafrost degradation based on long-term field observation;(3)focus intensively on the dynamics of greenhouse gas flux in permafrost degradation of Northeast China and the feedback of greenhouse gas emissions to climate change;(4)quantitative studies on the permafrost carbon feedback and vegetation carbon feedback due to permafrost change to climate multi-impact and estimate the balance of C in permafrost regions in the future. 展开更多
关键词 climate warming permafrost degradation greenhouse gas emissions ecosystem impact
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模拟增温对寒温带兴安落叶松林土壤及空气温湿度的影响 被引量:2
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作者 吴天龙 马秀枝 +3 位作者 梁芝 高伟 刘洋 张晓璞 《东北林业大学学报》 CAS CSCD 北大核心 2023年第1期74-81,共8页
采用开顶室(OTC)模拟增温的方法,设置增温组(OTC,模拟增温)和对照组(CK,无处理),通过连续1 a(2019年11月—2020年10月)的野外原位观测试验,探讨了模拟增温对兴安落叶松(Larix gmelinii)林内各层土壤(5、10、15、20 cm)以及地上1.5 m处... 采用开顶室(OTC)模拟增温的方法,设置增温组(OTC,模拟增温)和对照组(CK,无处理),通过连续1 a(2019年11月—2020年10月)的野外原位观测试验,探讨了模拟增温对兴安落叶松(Larix gmelinii)林内各层土壤(5、10、15、20 cm)以及地上1.5 m处空气温湿度的影响。结果表明:(1)与对照相比,OTC内地下5~20 cm土壤年均温度依次增幅1.18、1.83、1.69、1.29℃,地上空气温度增幅1.18℃;土壤年均湿度较CK依次降低2.31%、1.85%、1.14%、5.07%,空气湿度降低2.15%。土壤年均温度在各层次间无显著差异。20 cm的土壤湿度最高,且显著高于其他土层。(2)土壤和空气月均温度在模拟增温和对照处理下均呈“先下降后上升”的趋势;增温处理下的空气温度高于对照。土壤湿度月变化呈现出生长季(6—9月)变化波动大,非生长季(10月—翌年5月)变化波动小的趋势。(3)模拟增温处理下,5、10 cm土壤温度在秋季具有显著差异。(4)模拟增温和对照处理下,夏季夜间的15、20 cm土壤湿度与5、10 cm间的差异具有显著性。综上,开顶室能够有效改变微气候环境,对地上1.5 m、地下5、10、15、20 cm土壤有一定的增温降湿效应。 展开更多
关键词 多年冻土 模拟增温 土壤温度 土壤湿度
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保护多年冻土,助力双碳目标的实现 被引量:1
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作者 罗栋梁 金会军 +5 位作者 吴青柏 何瑞霞 张林 王金牛 李晓英 李世珍 《西藏科技》 2023年第11期82-87,F0002,共7页
多年冻土是冰冻圈系统的重要组成成分,因具有特殊的水热物理和力学性质,其生态系统服务功能如固碳增汇、净化水质、调节水文气候、水源涵养和贮存等也较为特殊。近几十年来,随着气候变化和人类活动干扰增强,多年冻土正在发生快速、广泛... 多年冻土是冰冻圈系统的重要组成成分,因具有特殊的水热物理和力学性质,其生态系统服务功能如固碳增汇、净化水质、调节水文气候、水源涵养和贮存等也较为特殊。近几十年来,随着气候变化和人类活动干扰增强,多年冻土正在发生快速、广泛而深刻的退化,突出表现为地温升高、活动层加深、季节冻深变浅、岛状多年冻土消失、多年冻土分布下界抬升、融区扩展等。当前,我国正努力推动实现碳达峰碳中和目标,多年冻土作为陆地生态系统最大土壤有机碳库,是实现双碳目标的关键环节。我们认为,通过植被建植技术、繁育固碳能力强的苔藓草丛、微生物技术改变浅表层传热过程和水文条件等,构建接近自然状态的冻土保护技术体系是减少温室气体排放的关键路径之一,相关技术的研发将助力我国双碳目标的实现。 展开更多
关键词 多年冻土 气候变暖 冻土退化 接近自然状态的冻土保护技术
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典型冰冻圈区域河流黑碳研究进展 被引量:1
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作者 赵玉娇 高坛光 +1 位作者 张玉兰 康世昌 《冰川冻土》 CSCD 北大核心 2023年第2期327-340,共14页
冰冻圈区域河流是连接冰冻圈及河流中下游,乃至海洋碳库的重要通道。气候变暖导致冰冻圈快速萎缩,致使储存在冰川和冻土中的黑碳暴露并迁移,深刻影响冰冻圈区域河流黑碳的来源及输移过程,对海陆碳循环具有重要意义。本文重点综述了青藏... 冰冻圈区域河流是连接冰冻圈及河流中下游,乃至海洋碳库的重要通道。气候变暖导致冰冻圈快速萎缩,致使储存在冰川和冻土中的黑碳暴露并迁移,深刻影响冰冻圈区域河流黑碳的来源及输移过程,对海陆碳循环具有重要意义。本文重点综述了青藏高原、北极、阿尔卑斯山脉、落基山脉以及安第斯山脉等典型冰冻圈区域河流黑碳的通量、来源以及传输运移途径。结果表明:典型冰冻圈区域河流黑碳的传输通量约为2.29 Tg·a^(-1),约占全球河流黑碳通量的5.33%。除大气干湿沉降和径流侵蚀外,冰川消融和冻土退化对冰冻圈区域河流黑碳浓度及通量变化具有显著影响,其中青藏高原和阿拉斯加冰川消融每年释放进入河流的黑碳通量分别为10.00 Gg(7.74~12.30 Gg)和0.60 Gg(0.47~0.73 Gg)。然而,冻土退化对冰冻圈区域河流黑碳的影响程度尚不清楚。总体而言,冰冻圈区域河流黑碳的研究不足将严重限制区域乃至全球碳循环的系统认识,未来亟需加强冰冻圈区域河流黑碳的系统监测与研究,为量化全球变暖背景下冰冻圈区域河流黑碳变化及其影响提供科学数据。 展开更多
关键词 冰冻圈 河流黑碳 全球变暖 冰川 多年冻土
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高温冻土区块石护坡路基长期热状况观测与预测研究 被引量:3
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作者 王佳 赵静宜 +4 位作者 陈领 穆彦虎 张坤 毛云程 李国玉 《中国铁道科学》 EI CAS CSCD 北大核心 2023年第6期34-45,共12页
块石护坡在多年冻土区路基工程建设和维护中已得到广泛应用。近年来,有关块石护坡的降温效能存在一些争议,尤其是在高温冻土区其能否抵御气候变暖的不利影响这一问题引起了学者的关注。基于青藏铁路近20年现场观测数据和数值模拟预测,... 块石护坡在多年冻土区路基工程建设和维护中已得到广泛应用。近年来,有关块石护坡的降温效能存在一些争议,尤其是在高温冻土区其能否抵御气候变暖的不利影响这一问题引起了学者的关注。基于青藏铁路近20年现场观测数据和数值模拟预测,探讨气候变暖背景下高温冻土区块石护坡路基50年内的热状况演化规律以及天然场地高温冻土退化过程。结果表明:块石护坡路基能够有效抬升人为冻土上限,路基运营20年后人为冻土上限较原天然上限仍有近2 m的抬升;路基运营20年内,浅层冻土地基存在明显升温过程,导致人为上限以下形成厚度达6~8 m的高温冻土层,其压缩和蠕变变形可引发量值可观的路基沉降变形;在50年气温升高2.6℃情景下,路基运营30年后人为冻土上限下降至同期天然场地冻土上限水平,此后路基人为上限与天然冻土上限同步下降,会进一步引发显著的路基沉降变形。对于高温冻土区块石护坡路基而言,依据路基热状况和变形发展过程,适时采用如热管类的补强措施是必要的。 展开更多
关键词 青藏铁路 块石护坡 高温冻土 气候变暖 路基热状况
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不同边界条件对多年冻土上限影响的模型试验研究 被引量:27
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作者 冯文杰 李东庆 +1 位作者 马巍 张鲁新 《冰川冻土》 CSCD 北大核心 2001年第4期353-359,共7页
在全球气候转暖对多年冻土影响的情景下 ,开展了在多模式下气温升高对冻土上限的影响试验研究 .针对不加抛石遮阳棚、加抛石、加抛石遮阳棚 3种情况 ,地表温度均采取基本温度加 2次不同升温冻融循环 ,每次温控指标逐级提高 0 .5℃ ,即... 在全球气候转暖对多年冻土影响的情景下 ,开展了在多模式下气温升高对冻土上限的影响试验研究 .针对不加抛石遮阳棚、加抛石、加抛石遮阳棚 3种情况 ,地表温度均采取基本温度加 2次不同升温冻融循环 ,每次温控指标逐级提高 0 .5℃ ,即地表温度 3次变化依次按照 - 16 .1~ 5 .8~ - 13.3℃、 - 15 .6~ 6 .3~ - 12 .8℃、 - 15 .1~ 6 .8~ - 12 .3℃进行 .结果表明 ,加抛石及遮阳棚对多年冻土上限有着明显的影响 ,冻土上限的变化与气温基本上呈正相关 。 展开更多
关键词 抛石 遮阳棚 气候转暖 多年冻土上限 地表温度 气温
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气候变暖背景下青藏高原多年冻土层中地下冰作为水“源”的可能性探讨 被引量:21
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作者 吴吉春 盛煜 +2 位作者 吴青柏 李静 张秀敏 《冰川冻土》 CSCD 北大核心 2009年第2期350-356,共7页
多年冻土中含有大量地下冰,全球气候变暖势必导致多年冻土退化,地下冰融化,部分水分被释放并参与到区域水循环之中,改变了区域水文状况.冻土退化-释水的过程在监测上面临较大困难,无法提供直接证据,但其长期累计的效果在宏观水文过程中... 多年冻土中含有大量地下冰,全球气候变暖势必导致多年冻土退化,地下冰融化,部分水分被释放并参与到区域水循环之中,改变了区域水文状况.冻土退化-释水的过程在监测上面临较大困难,无法提供直接证据,但其长期累计的效果在宏观水文过程中表现显著.为此,利用近年来青藏高原部分湖泊水位变化监测以及地区水文情势变化研究成果,探讨了在气候变暖背景下,多年冻土层中的地下冰作为一种潜在水"源"的可能性.结果表明:多年冻土退化较强烈地区,补给源头在多年冻土区的封闭湖泊水位上涨、地下水位上升,排除其它补给量增加的可能性后,多年冻土地下冰很可能是补给水量增加的原因之一. 展开更多
关键词 气候变暖 多年冻土退化 地下冰融化 潜在水源
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“冷却路基”方法在青藏铁路上的应用 被引量:44
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作者 程国栋 孙志忠 牛富俊 《冰川冻土》 CSCD 北大核心 2006年第6期797-808,共12页
青藏铁路穿越550 km多年冻土,其中约一半为高温多年冻土,其年平均地温为0^-1℃.青藏铁路是百年大计,必须考虑未来50~100 a的气候变化.在全球变暖的背景下,青藏铁路高温冻土段的建设必须改变单纯依靠热阻(增加路堤高度、采用保温材料等)... 青藏铁路穿越550 km多年冻土,其中约一半为高温多年冻土,其年平均地温为0^-1℃.青藏铁路是百年大计,必须考虑未来50~100 a的气候变化.在全球变暖的背景下,青藏铁路高温冻土段的建设必须改变单纯依靠热阻(增加路堤高度、采用保温材料等)的消极“保”温方法,而改用“冷却路基”的积极“降”温措施.青藏铁路的建设采用了一整套“冷却路基”的方法:通过遮阳板调控辐射;通过通风管、热管和气冷路堤调控对流;通过“热半导体”材料调控传导;通过这些调控方式的组合,加强冷却效果.这些方法均可有效地降低路基下多年冻土的地温,保证青藏铁路路基的稳定. 展开更多
关键词 青藏铁路 高温冻土 气候转暖 冷却路基
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东北多年冻土退化及环境效应研究现状与展望 被引量:24
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作者 陈珊珊 臧淑英 孙丽 《冰川冻土》 CSCD 北大核心 2018年第2期298-306,共9页
东北多年冻土属中高纬度多年冻土,对气候变化非常敏感。数据模型模拟表明,21世纪东北多年冻土区气温会持续上升,显著的变暖将导致多年冻土退化。东北多年冻土呈现自南向北的区域性退化趋势,多年冻土区南部表现为南界的北移、融区的扩大... 东北多年冻土属中高纬度多年冻土,对气候变化非常敏感。数据模型模拟表明,21世纪东北多年冻土区气温会持续上升,显著的变暖将导致多年冻土退化。东北多年冻土呈现自南向北的区域性退化趋势,多年冻土区南部表现为南界的北移、融区的扩大和多年冻土的消失,而北部表现为多年冻土下限的上移、活动层厚度增大及地温升高等。多年冻土的退化会导致寒区生态环境的恶化,如兴安落叶松占绝对优势的天然林带锐减,林带北移,沼泽湿地萎缩等。随着多年冻土的迅速退缩和变薄,原多年冻土中蕴藏的碳将释放出来,对气候变化产生积极的正反馈,加速变暖,并影响全球碳循环。多年冻土退化导致其热状态失稳而造成寒区基础设施损坏,并且影响冻土微生物、碳循环、寒区生态和水文等,而它们是区域气候变化的重要因子,也将成为未来多年冻土研究的重点。而这些研究都需要长期的基础数据作支撑,因此需要进一步完善冻土参数监测网络,用模型厘清气候变化与多年冻土退化及其环境效应之间的关系。 展开更多
关键词 气候变暖 多年冻土退化 环境效应 东北
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高温冻土区填土路基的地基融化固结变形分析 被引量:7
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作者 田亚护 张青龙 +1 位作者 穆彦虎 刘永智 《中国铁道科学》 EI CAS CSCD 北大核心 2014年第3期1-7,共7页
针对青藏铁路高温冻土区普通填土路基的融沉变形,基于拉格朗日法描述的大变形固结理论及考虑相变作用的路基传热理论,对高温冻土区不同高度填土路基的温度场和地基融化固结变形进行计算分析,并与现场监测结果进行对比。温度场分析结果表... 针对青藏铁路高温冻土区普通填土路基的融沉变形,基于拉格朗日法描述的大变形固结理论及考虑相变作用的路基传热理论,对高温冻土区不同高度填土路基的温度场和地基融化固结变形进行计算分析,并与现场监测结果进行对比。温度场分析结果表明,高温冻土区4和6m高填土路基在短期内可使冻土上限略微抬升,但下伏多年冻土存在缓慢升温过程,其升温幅度每年约为0.02℃左右;随着气候逐渐变暖,填土路基下冻土上限在后期会逐渐下降,且填土路基高度越小则上限下降量越大,最终在路基下部形成融化盘。融化固结变形分析结果表明,填土路基沉降变形表现出季节性,即暖季沉降变形发展迅速,冷季发展缓慢,发展趋势与现场监测结果吻合良好;在给定的地质条件下,2,4和6m高填土路基在竣工50年后其沉降变形量分别为255.2,470.4和689.7mm,即沉降变形量与其高度呈正比,且高填土路基沉降变形的季节性更显著;填土路基高度和多年冻土的含冰量是影响填土路基沉降变形的主要因素。 展开更多
关键词 青藏铁路 填土路基 高温冻土 融沉变形
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高温多年冻土区冻土地基预先融化技术研究现状及展望 被引量:5
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作者 郝加前 吉延峻 +4 位作者 何乃武 魏智 杨思忠 何瑞霞 金会军 《冰川冻土》 CSCD 北大核心 2007年第4期645-652,共8页
在气候变暖背景下,多年冻土退化加剧,高温冻土将会在更大范围出现,保护冻土原则的适用性将受到经济、技术、环保合理性的挑战.在条件适宜高温冻土区,根据建筑结构和基础类型,采用预先融化技术(简称预融技术)处理冻土地基可在经济合理的... 在气候变暖背景下,多年冻土退化加剧,高温冻土将会在更大范围出现,保护冻土原则的适用性将受到经济、技术、环保合理性的挑战.在条件适宜高温冻土区,根据建筑结构和基础类型,采用预先融化技术(简称预融技术)处理冻土地基可在经济合理的前提下,保证工程的安全可靠性和长期稳定性.回顾了国内外冻土区预先融化技术的经验,总结和展望了预融技术在工程设计、施工及运行中的三个基本步骤,包括施工前多年冻土的融化、已融土的密实和固结,工程运行期间保持融化和防止冻胀措施的实施.预融技术主要利用蒸汽,热、冷水的对流换热和电流热效应,以及改变地表热状况来融化下伏多年冻土.保持融化的方法主要包括改变地表反射率和地基土的结构,融土保温以及利用主动和被动升温传热装置等(如热管技术).结合中国东北的一些预融技术运用实例,如漠河机场工程等,简要评述了预融技术的应用效果. 展开更多
关键词 气候变暖 高温冻土 冻土退化 融沉破坏 预融技术
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