地理科学 ›› 2016, Vol. 36 ›› Issue (4): 588-596.doi: 10.13249/j.cnki.sgs.2016.04.013

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黄河源区冻土分布制图及其热稳定性特征模拟

李静1, 盛煜1(), 吴吉春1, 冯子亮1, 宁作君1,2, 胡晓莹1, 张秀敏3   

  1. 1.中国科学院寒区旱区环境与工程研究所冻土工程国家重点实验室,甘肃 兰州 730000
    2.甘肃土木工程科学研究院,甘肃 兰州730000
    3.陕西省地方电力(集团)有限公司,陕西 西安710000
  • 收稿日期:2015-03-18 修回日期:2015-07-28 出版日期:2016-07-21 发布日期:2016-07-21
  • 作者简介:

    作者简介:李静(1979-),女,山西长治人,副研究员,主要从事多年冻土环境与分布研究。E-mail: li_jing9797@lzb. ac. cn

Mapping Frozen Soil Distribution and Modeling Permafrost Stability in the Source Area of the Yellow River

Jing Li1, Yu Sheng1(), Jichun Wu1, Ziliang Feng1, Zuojun Ning1,2, Xiaoying Hu1, Xiumin Zhang3   

  1. 1. State Key Laboratory of Frozen Soil Engineering, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, Gansu, China
    2. Gansu Institute of Civil Engineering, Lanzhou 730000, Gansu , China
    3.Shaanxi Regional Electric PowerGroup Company Limited, Xi’an 710000, Shaanxi, China
  • Received:2015-03-18 Revised:2015-07-28 Online:2016-07-21 Published:2016-07-21
  • Supported by:
    中科院重点部署项目(KZZD-EW-13)、国家重点基础研究发展计划(973 计划)项目(2013CBA01803)和冻土工程国家重点实验室自主课题(SKLFSE-ZT-10)资助;Chinese Academy of Sciences Key Research Program (KZZD-EW-13)Major State Basic Research Development Program of China (2013CBA01803), Research Program of State Key Laboratory of Frozen Soil Engineering of Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences ( SKLFSE-ZT-10)

摘要:

以黄河源区多年冻土分布现状和热力特征为研究目标,通过野外调查及实测数据,分析了黄河源区不同地形地貌、不同地表覆盖条件下的冻土形成、分布特征和以地温为基础的热学特征,探讨了不同尺度因素对多年冻土分布的影响。结果表明,在高程低于4 300 m的平原区,多年冻土多不发育;在高于4 350 m的山区,局地地形对多年冻土的形成与分布作用显著。除阳坡地形外,多年冻土均比较发育;介于4 300~4 350 m的低山丘陵和平原区,局地地形、地表植被、土壤湿度等因素共同决定着多年冻土的形成和分布格局。以年均地温指标为基础,构建了以纬度、经度和高程为自变量的回归模型,并对阳坡地形进行微调和校正。结果表明,以0oC作为划分季节冻土和多年冻土的标准和界限,多年冻土面积2.5×104km2,约占整个源区面积的85.1%;季节冻土面积0.3×104km2,约占整个源区面积的9.7%。进一步以0.5oC或1.0oC为分类间隔绘制了黄河源区多年冻土热稳定性空间分布图。

关键词: 冻土分布, 多年冻土热稳定性, 年均地温, 黄河源

Abstract:

The source area of the Yellow River (SAYR) is located in the eastern-to-medium part of the Qinghai-Tibet Plateau. Permafrost in the SAYR experienced remarkable degradation in the past. Taking distribution patterns of frozen soil and permafrost stability as research object, the characteristics of permafrost development and distribution patterns at various terrains and land covers were analyzed based on a large amount of field investigations and the measurements. In addition, thermal features of permafrost were analyzed based on the measured ground temperatures at various depths. The effects of the geological and geographic factors on permafrost distribution and thermal stability were discussed. It was indicated that: 1) Permafrost was occasionally developed in the various fluvial and proluvial plains with elevation generally lower than 4 300 m; 2) Permafrost was widely distributed in the mountains higher than 4 350 m except for the sunny slope terrain, where local terrain played an important role in permafrost development and distribution; 3) The combinations of local terrain, surficial vegetation, soil wetness and moisture conditions all contributed to the formation and distribution of permafrost in the low hills and mountains where elevation ranged in 4 300-4 350 m.Taking the annual mean ground temperature (MAGT) as the basis, an experiential-statistical MAGT-based model was constructed, of which latitude, longitude and elevation were set up as independent variables. Together with DEM data, permafrost MAGTs were primarily modeled using the statistically regression model. And then, the modeled results in the south-facing areas were slightly adjusted, and a secondly model was constructed to model permafrost distribution in the shady areas. Thirdly, the combined modeling results were locally adjusted using the measurements. The frozen soil map in the SAYR was thus compiled. Taking 0oC as the boundary between permafrost and seasonally frozen soil, it was indicated that permafrost was distributed in an area of 2.5×104km2, which occupied approximately 85.1% in the SAYR, and that seasonally frozen soil was distributed in an area of 0.3×104km2 with an areal percentage of 9.7%. Permafrost was further divided into seven stability taking 0.5oC or 1.0oC of MAGTs as intervals.They were the first zone with permafrost MAGT smaller than -4.0oC, the second zone with permafrost MAGT varying between -4.0oC and -3.0oC, the third zone with permafrost MAGT varying between -3.0oC and -2.0oC, the fourth zone with permafrost MAGT varying between -2.0oC and -1.0oC, the fifth zone with permafrost MAGT varying between -1.0oC and -0.5oC, the sixth zone with permafrost MAGT varying between -0.5oC and 0oC, and the seventh zone with permafrost MAGT higher than 0oC.

Key words: permafrost distribution, permafrost thermal stability, mean annual ground temperature, the source area of the Yellow River

中图分类号: 

  • P461.4