青藏公路沿线多年冻土区活动层起始冻融时间的时空变化特征和影响因素

doi:10.7522/j.issn.1000-0240.2018.0413

摘要/Abstract

摘要： 多年冻土区活动层冻融格局对气候系统、能量平衡、水文过程和生态系统有重要的影响，地表冻融时间是反映冻融格局时空变化的重要指标。为了探明多年冻土区活动层起始冻融时间的影响因素和机制，通过对青藏公路沿线8个典型活动层观测场地表起始融化时间（OOT）和起始冻结时间（OOF）进行研究，分析了不同观测场起始冻融时间的时空差异及其影响因素。结果表明：（1）青藏高原多年冻土区活动层起始融化主要发生在4月中下旬，起始冻结主要发生在10月中下旬。OOT的年际变化幅度远大于OOF，每年起始冻结的发生较起始融化更为准时。（2）起始融化发生时的气温普遍比起始冻结发生时高1~4℃。气温对OOT的影响要比对OOF大，其中OOT的变化主要与春季气温有关，冬季气温对其影响不大。（3）植被和土壤水分对OOT和OOF有重要调节作用，土壤含水率越高，植被状况越好，起始融化和冻结的发生时间往往越迟。（4）在起始融化和冻结阶段，厚度较大和持续时间较长的积雪对地温变化有明显的抑制作用，对OOT和OOF有延迟作用。

关键词: 多年冻土, 活动层, 冻融, 青藏高原, 青藏公路

Abstract: The situation of freezing and thawing within the active layer has a vital influence on the climate system, energy balance, hydrological processes and ecological system, and the onset date of freezing and thawing is an important index to describe the spatial and temporal variations of freezing and thawing condition. In order to find out the influence factors and process on onset of freezing and thawing within the active layer, eight typical observation sites in permafrost regions along the Qinghai-Tibet Highway were selected, and their onset date of freezing (OOF) and the onset date of thawing (OOT) at each site are analyzed. The analyses showed that:(1) Within the active layer in permafrost on the Tibetan Plateau, the initial thawing occurs mainly in the middle to late April, and the initial freezing occurs mainly in the middle to late October; the annual variation of OOT is greater than that of OOF, and the freezing of the active layer occurs more regular than thawing. (2) The air temperature when the initial thawing of the active layer occurs is generally 1-4℃ higher than that when the initial freezing occurs; the effect of air temperature at OOT is greater than that at OOF; the variation of OOT is mainly related to the mean air temperature in spring, and barely influenced by the mean air temperature in winter. (3) Vegetation and soil moisture play an important role to OOT and OOF; high soil moisture, as well as nice vegetation, generally delays the onset of freezing and thawing. (4) When the freezing or thawing is about to start, snow cover with great depth or rather long duration obviously inhibits the rising of ground temperature and then delays the OOT and OOF, however, this is an occasional event.

Key words: permafrost, active layer, freezing and thawing, Tibetan Plateau, Qinghai-Tibet Highway

中图分类号:

P642.14

刘广岳, 谢昌卫, 杨淑华. 青藏公路沿线多年冻土区活动层起始冻融时间的时空变化特征和影响因素[J]. 冰川冻土, 2018, 40(6): 1067-1078.

LIU Guangyue, XIE Changwei, YANG Shuhua. Spatial and temporal variation characteristics on the onset dates of freezing and thawing of active layer and its influence factors in permafrost regions along the Qinghai-Tibet Highway[J]. Journal of Glaciology and Geocryology, 2018, 40(6): 1067-1078.

参考文献

[1] Skogland T, Lomeland S, Goks Y J. Respiratory burst after freezing and thawing of soil:experiments with soil bacteria[J]. Soil Biology and Biochemistry, 1988, 20(6):851-856.
[2] Cherkauer K A, Lettenmaier D P. Hydrologic effects of frozen soils in the upper Mississippi River basin[J]. Journal of Geophysical Research:Atmospheres, 1999, 104(D16):19599-19610.
[3] Zhang T, Armstrong R L. Soil freeze/thaw cycles over snow-free land detected by passive microwave remote sensing[J]. Geophysical Research Letters, 2001, 28(5):763-766.
[4] Smith N V, Saatchi S S, Randerson J T. Trends in high northern latitude soil freeze and thaw cycles from 1988 to 2002[J/OL]. Journal of Geophysical Research:Atmospheres, 2004, 109(D12)[2018-05-11]. https://doi.org/10.1029/2003JD004472.
[5] Matzner E, Borken W. Do freeze-thaw events enhance C and N losses from soils of different ecosystems?:a review[J]. European Journal of Soil Science, 2008, 59(2):274-284.
[6] Han L J, Tsunekawa A, Tsubo M. Monitoring near-surface soil freeze-thaw cycles in northern China and Mongolia from 1998 to 2007[J]. International Journal of Applied Earth Observation and Geoinformation, 2010, 12(5):375-384.
[7] Shen Yongping, Wang Guoya. Key findings and assessment results of IPCC WGI fifth assessment report[J]. Journal of Glaciology and Geocryology, 2013, 35(5):1068-1076.[沈永平, 王国亚. IPCC第一工作组第五次评估报告对全球气候变化认知的最新科学要点[J]. 冰川冻土, 2013, 35(5):1068-1076.]
[8] Oechel W C, Vourlitis G L, Hastings S J, et al. Acclimation of ecosystem CO₂ exchange in the Alaskan Arctic in response to decadal climate warming[J]. Nature, 2000, 406(6799):978-981.
[9] Zhang Tingjun, Jin Rui, Gao Feng. Overview of the satellite remote sensing of frozen ground:passive microwave sensors[J]. Advances in Earth Science, 2009, 24(10):1073-1083.[张廷军, 晋锐, 高峰. 冻土遥感研究进展:被动微波遥感[J]. 地球科学进展, 2009, 24(10):1073-1083.]
[10] Frolking S, Goulden M L, Wofsy S C, et al. Modelling temporal variability in the carbon balance of a spruce/moss boreal forest[J]. Global Change Biology, 1996, 2(4):343-366.
[11] Keeling C D, Chin J F S, Whorf T P. Increased activity of northern vegetation inferred from atmospheric CO₂ measurements[J]. Nature, 1996, 382(6587):146-149.
[12] Li X, Cheng G. A GIS-aided response model of high-altitude permafrost to global change[J]. Science in China:Series DEarth Sciences, 1999, 42(1):72-79.
[13] Wang Chenghai, Dong Wenjie, Wei Zhigang. Study on relationship between the frozen-thaw process in Qinghai-Xizang Plateau and circulation in East-Asia[J]. Chinese Journal of Geophysics, 2004, 46(3):309-316.[王澄海, 董文杰, 韦志刚. 青藏高原季节冻融过程与东亚大气环流关系的研究[J]. 地球物理学报, 2003, 46(3):309-316.]
[14] Liu X, Chen B. Climatic warming in the Tibetan Plateau during recent decades[J]. International Journal of Climatology, 2000, 20(14):1729-1742.
[15] Gao Rong, Wei Zhigang, Dong Wenjie, et al. Variation of the snow and frozen soil over Qinghai-Xizang Plateau in the late twentieth century and their relations to climatic change[J]. Plateau Meteorology, 2003, 22(2):191-196.[高荣, 韦志刚, 董文杰, 等. 20世纪后期青藏高原积雪和冻土变化及其与气候变化的关系[J]. 高原气象, 2003, 22(2):191-196.]
[16] Li Xin, Jin Rui, Pan Xiaoduo, et al. Changes in the near-surface soil freeze-thaw cycle on the Qinghai-Tibetan Plateau[J]. International Journal of Applied Earth Observations and Geoinformation, 2012, 17(1):33-42.
[17] Li Ren, Zhao Lin, Ding Yongjian, et al. Temporal and spatial variations of the active layer along the Qinghai-Tibet Highway in a permafrost region[J]. Chinese Science Bulletin, 2012, 57(35):4609-4616.
[18] Chen Boli, Luo Siqiong, Lü Shihua, et al. Land surface characteristics in soil freezing and thawing process on the Tibetan Plateau based on community land model[J]. Journal of Glaciology and Geocryology, 2017, 39(4):760-770.[陈渤黎, 罗斯琼, 吕世华, 等. 基于CLM模式的青藏高原土壤冻融过程陆面特征研究[J]. 冰川冻土, 2017, 39(4):760-770.]
[19] Zhang Yu, Li Dongqing, Ming Feng. Experimental study of the freezing front movement owing to freezing-thawing cycles[J]. Journal of Glaciology and Geocryology, 2016, 38(3):679-684.[张宇, 李东庆, 明锋. 冻融循环作用下土体冻结锋面移动规律试验研究[J]. 冰川冻土, 2016, 38(3):679-684.]
[20] Zhang Hai'ou, Han Jichang, Zhang Yang, et al. Effects of freezing-thawing on soil aggregates of Pisha sandstone and sand compound soil[J]. Journal of Glaciology and Geocryology, 2016, 38(1):186-191.[张海欧, 韩霁昌, 张扬, 等. 冻融交替对砒砂岩与沙复配土壤团粒结构的影响[J]. 冰川冻土, 2016, 38(1):186-191.]
[21] Henry H A L. Soil freeze-thaw cycle experiments:trends, methodological weaknesses and suggested improvements[J]. Soil Biology and Biochemistry, 2007, 39(5):977-986.
[22] Chen H, Zhu Q, Wu N, et al. Delayed spring phenology on the Tibetan Plateau may also be attributable to other factors than winter and spring warming[J/OL]. Proceedings of the National Academy of Sciences of the United States of America, 2011, 108(19)[2018-05-11]. https://doi.org/10.1073/pnas.1100091108.
[23] Guo Dongnan, Zang Shuying, Zhao Guangying. Effect of freezing and thawing cycles on soil microbial activity and organic carbon density in forest swamp wetland with various drainage afforestation years[J]. Journal of Glaciology and Geocryology, 2017, 39(1):175-184.[郭冬楠, 臧淑英, 赵光影. 冻融交替对不同年代排水造林湿地土壤微生物活性及有机碳密度的影响[J]. 冰川冻土, 2017, 39(1):175-184.]
[24] Ding Yongjian, Ye Baisheng, Liu Shiyin, et al. Monitoring and study of large scale permafrost hydrological process in Tibetan Plateau[J]. Chinese Science Bulletin, 2000, 45(2):208-214.[丁永建, 叶佰生, 刘时银, 等. 青藏高原大尺度冻土水文监测研究[J]. 科学通报, 2000, 45(2):208-214.]
[25] Cheng Huiyan, Wang Genxu, Wang Yibo, et al. Variations of soil temperature and water moisture of seasonal frozen soil with different vegetation coverages in the source region of the Yellow River, China[J]. Journal of Lanzhou University (Natural Sciences), 2008, 44(2):15-21.[程慧艳, 王根绪, 王一博, 等. 黄河源区不同植被类型覆盖下季节冻土冻融过程中的土壤温湿空间变化[J]. 兰州大学学报(自然科学版), 2008, 44(2):15-21.]
[26] Liu Guangsheng, Wang Genxu, Hu Hongchang, et al. Influence of vegetation coverage on water and heat processes of the active layer in permafrost region of the Tibet Plateau[J]. Journal of Glaciology and Geocryology, 2009, 31(1):89-95.[刘光生, 王根绪, 胡宏昌, 等. 青藏高原多年冻土区植被盖度变化对活动层水热过程的影响[J]. 冰川冻土, 2009, 31(1):89-95.]
[27] Shen M, Sun Z, Wang S, et al. No evidence of continuously advanced green-up dates in the Tibetan Plateau over the last decade[J/OL]. Proceedings of the National Academy of Sciences of the United States of America, 2013, 110(26)[2018-05-11]. https://doi.org/10.1073/pnas.1304625110.
[28] Yu H Y, Luedeling E, Xu J C. Winter and spring warming result in delayed spring phenology on the Tibetan Plateau[J]. Proceedings of the National Academy of Sciences of the United States of America, 2010, 107(51):22151-22156.
[29] Zhang G, Zhang Y, Dong J, et al. Green-up dates in the Tibetan Plateau have continuously advanced from 1982 to 2011[J]. Proceedings of the National Academy of Sciences of the United States of America, 2013, 110(11):4309-4314.
[30] Shen M. Spring phenology was not consistently related to winter warming on the Tibetan Plateau[J/OL]. Proceedings of the National Academy of Sciences of the United States of America, 2011, 108(19)[2018-05-11]. https://doi.org/10.1073/pnas.1018390108.
[31] Wu Qingbai, Zhang Tingjun. Changes in active layer thickness over the Qinghai-Tibetan Plateau from 1995 to 2007[J/OL]. Journal of Geophysical Research:Atmospheres, 2010, 115(D9)[2018-05-11]. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2009JD012974.
[32] Myneni R B, Keeling C D, Tucker C J, et al. Increased plant growth in the northern high latitudes from 1981 to 1991[J]. Nature, 1997, 386(6626):698-702.
[33] Ding Mingjun, Zhang Yili, Sun Xiaomin, et al. Spatiotemporal variation in alpine grassland phenology in the Qinghai-Tibetan Plateau from 1999 to 2009[J]. Chinese Science Bulletin, 2013, 58(3):396-405.
[34] Kreyling J, Beierkuhnlein C, Pritsch K, et al. Recurrent soil freeze-thaw cycles enhance grassland productivity[J]. New Phytologist, 2008, 177(4):938-945.
[35] Xu Xingkui, Chen Hong, Levy J K. Spatiotemporal vegetation cover variations in the Qinghai-Tibet Plateau under global climate change[J]. Chinese Science Bulletin, 2008, 53(6):915-922.
[36] Liu Junhui, Gao Jixi, Wang Wenjie. Variations of vegetation coverage and its relations to global climate changes on the Tibetan Plateau during 1981-2005[J]. Journal of Mountain Science, 2013, 31(2):234-242.[刘军会, 高吉喜, 王文杰. 青藏高原植被覆盖变化及其与气候变化的关系[J]. 山地学报, 2013, 31(2):234-242.]
[37] Qi Ruying, Wang Qilan. Responses of beginning freeze and thaw phase of soil surface to climate change in Qinghai[J]. Chinese Journal of Agrometeorology, 2006, 27(2):134-138.[祁如英, 王启兰. 青海地表始冻期和解冻期对气候变化的响应[J]. 中国农业气象, 2006, 27(2):134-138.]
[38] Yu Haiying, Xu Jianchu. Effects of climate change on vegetations on Qinghai-Tibet Plateau:a review[J]. Chinese Journal of Ecology, 2009, 28(4):747-754.[于海英, 许建初. 气候变化对青藏高原植被影响研究综述[J]. 生态学杂志, 2009, 28(4):747-754.]
[39] Zhang Tingjun. Influence of the seasonal snow cover on the ground thermal regime:an overview[J/OL]. Reviews of Geophysics, 2005, 43(4)[2018-05-11]. https://doi.org/10.1029/2004RG000157.
[40] Yang M, Yao T, Nelson F, et al. Snow cover and depth of freeze-thaw on the Tibetan Plateau:a case study from 1997 to 1998[J]. Physical Geography, 2008, 29(3):208-221.
[41] Sun Linchan, Zhao Lin, Li Ren, et al. The influence of snow cover on the surface albedo and ground temperature[J]. Journal of Mountain Science, 2010, 28(3):266-273.[孙琳婵, 赵林, 李韧, 等. 西大滩地区积雪对地表反照率及浅层地温的影响[J]. 山地学报, 2010, 28(3):266-273.]
[42] Goodrich L E. The influence of snow cover on the ground thermal regime[J]. Cangeotechj, 1982, 19(4):421-432.
[43] Jin Huijun, Sun Liping, Wang Shaoling, et al. Dual influences of local environmental variables on ground temperatures on the interior-eastern Qinghai-Tibet Plateau (I):vegetation and snow cover[J]. Journal of Glaciology and Geocryology, 2008, 30(4):535-545.[金会军, 孙立平, 王绍令, 等. 青藏高原中、东部局地因素对地温的双重影响(I):植被和雪盖[J]. 冰川冻土, 2008, 30(4):535-545.]