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冰川冻土 ›› 2019, Vol. 41 ›› Issue (4): 926-936.doi: 10.7522/j.issn.1000-0240.2018.1107

• 寒旱区水文水资源 • 上一篇    下一篇

渭河流域西部季节冻融对浅层非饱和土壤水热变化的影响

丑亚玲1,2, 李永娥1,2, 王莉杰1,2, 曹伟3, 盛煜3   

  1. 1. 兰州理工大学 甘肃省土木工程防灾减灾重点实验室, 甘肃 兰州 730050;
    2. 兰州理工大学 西部土木工程防灾减灾教育部工程研究中心, 甘肃 兰州 730050;
    3. 中国科学院 西北生态环境资源研究院 冻土工程国家重点实验室, 甘肃 兰州 730000
  • 收稿日期:2018-07-27 修回日期:2018-09-26 出版日期:2019-08-25 发布日期:2019-11-28
  • 作者简介:丑亚玲(1976-),女,甘肃合水人,教授,2008年在中国科学院寒区旱区环境与工程研究所获博士学位,从事岩土工程教学与研究工作.E-mail:chouyaling@lzb.ac.cn.
  • 基金资助:
    国家自然科学基金项目(51769013)资助

Effects of seasonal freezing and thawing on the hydrothermal changes of the shallow unsaturated soil in the western Weihe River basin

CHOU Yaling1,2, LI Yong'e1,2, WANG Lijie1,2, CAO Wei3, SHENG Yu3   

  1. 1. Key Laboratory of Disaster Prevention and Mitigation in Civil Engineering of Gansu Province, Lanzhou University of Technology, Lanzhou 730050, China;
    2. Western Center for Disaster Mitigation in Civil Engineering of Ministry of Education, Lanzhou University of Technology, Lanzhou 730050, China;
    3. State Key Laboratory of Frozen Soil Engineering, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
  • Received:2018-07-27 Revised:2018-09-26 Online:2019-08-25 Published:2019-11-28

摘要: 以黄土高原渭河流域西部黄土丘陵沟壑区为研究区域,建立了野外观测场地,对该区域浅层非饱和土体冻融过程及水热运移规律对气候作用的响应过程进行了研究与分析。结果表明:气温对地温及地温变幅的影响随深度增加而迅速衰减,地温振幅随深度增加按指数规律衰减且温度波的相位随深度的增加而滞后,地表下200 cm深度以内地温振幅受气温影响较大。该区域裸露地表土壤的最大冻结深度在20~50 cm之间。在土壤冻结过程中,深层土壤未冻水逐渐向冻结层运移,导致深层含水量逐渐减少。不同深度土壤冻结系数随土壤深度的增加而减小,融化系数则相反。地表下50 cm深度以内的土体含水量受降水影响波动显著。土壤含水量与温度呈相似变化,地温峰值出现的时间总滞后于土壤水分,其变异程度均随土壤深度的增加而减小。

关键词: 渭河流域, 黄土高原, 季节冻土, 浅层土体, 冻融过程, 水热运移, 气象因子

Abstract: Taking the hilly and gully regions of the western Weihe River basin in the Loess Plateau as the research area,a field observation site was established. The response of freeze-thaw process and water-heat transfers of the shallow unsaturated soil in this area to climate change was studied and analyzed. The results show that the influence of air temperature on the ground temperature and its variation amplitude decrease rapidly with depth,the amplitude of ground temperature decreases exponentially with depth,and the phase of temperature wave lags with the depth. Furthermore,the influence of air temperature on the amplitude of soil temperature within 200 cm below the surface is more obvious. The maximum frozen depth of the bare surface soil in this area is about 20-50 cm. During the freezing period,the unfrozen water in the deep soil gradually migrates to the frozen layer,resulting in gradual decrease in the deep moisture content. The freezing coefficient of soil at different depth decreases with depth,while the thawing coefficient is the opposite. The soil moisture content within 50 cm below the surface fluctuates obviously under the influence of rainfall,and the soil moisture content and its temperature show similar tendency. The occurrence time of soil temperature peak is always lagged behind that of the soil moisture peak,and the degree of variation decreases with soil depth.

Key words: Weihe River basin, Loess Plateau, seasonally frozen soil, shallow soil, freeze-thaw process, water and heat transfers, meteorological factors

中图分类号: 

  • S152