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冰川冻土 ›› 2017, Vol. 39 ›› Issue (6): 1316-1325.doi: 10.7522/j.issn.1000-0240.2017.0324

• 寒旱区水文与水资源 • 上一篇    下一篇

青藏高原多年冻土区高寒草甸土壤水分入渗变化研究

朱美壮1,2, 王根绪1, 肖瑶1,2, 胡兆永1,2, 宋春林1,2, 黄克威1,2   

  1. 1. 中国科学院 水利部 成都山地灾害与环境研究所, 四川 成都 610041;
    2. 中国科学院大学, 北京 100049
  • 收稿日期:2017-06-07 修回日期:2017-10-10 出版日期:2017-12-25 发布日期:2018-04-03
  • 通讯作者: 王根绪,E-mail:wanggx@imde.ac.cn. E-mail:wanggx@imde.ac.cn
  • 作者简介:朱美壮(1992-),男,甘肃临洮人,2015年在兰州大学获学士学位,现为中国科学院成都山地灾害与环境研究所在读研究生,从事山地水文与生态研究.E-mail:zhumeiz@hotmail.com
  • 基金资助:
    重大研究计划重点支持项目“三江源区径流形成与变化机制及其冻土生态水文过程模拟”(91547203);国家重大科学研究计划“冰冻圈变化及其影响研究”第七课题“冰冻圈变化的生态过程及其对碳循环的影响”(No.2013CBA01807)资助

A study on the changes of soil water infiltration in alpine meadow of permafrost regions in the Tibetan Plateau

ZHU Meizhuang1,2, WANG Genxu1, XIAO Yao1,2, HU Zhaoyong1,2, SONG Chunlin1,2, HUANG Kewei1,2   

  1. 1. Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China;
    2. University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2017-06-07 Revised:2017-10-10 Online:2017-12-25 Published:2018-04-03

摘要: 在多年冻土区典型坡面上,将坡面划分为坡下(L)、坡中(M)和坡顶(H)三个坡位,每个坡位上各选取92%、60%和30%植被盖度为研究对象,用双环入渗仪测定土壤水分入渗过程,对影响土壤入渗过程的环境因子进行了分析,并基于土壤物理特性及土壤水分的测定进行模型模拟。结果表明:研究区不同植被盖度下土壤水分入渗性能在活动层冻融过程中差异明显,初始含水量和初始入渗率具有较好的负相关关系;稳定入渗率大小为:活动层融化期,92%(0.61 mm·min-1) > 60%(0.50 mm·min-1) > 30%(0.29 mm·min-1);活动层开始冻结期,60%(0.56 mm·min-1) > 30%(0.39 mm·min-1) > 92%(0.26 mm·min-1)。土壤水分入渗速率具有显著的坡位差异并与冻土的冻融循环过程关系紧密。主要表现为,稳定入渗速率随坡位高度的降低依次递减;同一坡位下,开始冻结期入渗速率小于融化期。在整个入渗阶段,坡顶的累积入渗量是最大的,体现了较好的入渗性能。影响高寒草甸土壤水分入渗的环境因子主要有容重,有机质含量及粒径<0.1 mm微粒。通过比较研究得出,在长江源地区,活动层融化期通用经验模型ft)=a+bt-n更适用于该研究区域高寒草甸土壤水分入渗过程的研究,而在开始冻结期Horton模型ft)=ic+(i0-ice-kt则具有更好的适用性。

关键词: 青藏高原, 多年冻土区, 土壤入渗, 冻融过程

Abstract: A typical slope of the permafrost regions was divided into three slope positions:the low (L), middle (M) and high (H) parts. The vegetation coverage of 92%, 60% and 30% for each slope position were selected as study objects to determine the soil water infiltration process by double ring infiltration apparatus. The environmental factors,which impact the process of soil infiltration, were analyzed and model simulation had done based on soil physical properties and soil water. The results showed that the soil water infiltration of different vegetation coverage in the study area had obvious difference during the freezing and thawing process of the active layer, and the initial soil water content had a good negative correlation with the initial infiltration rate. The stable infiltration rate was:vegetation coverage of 92% (0.61 mm·min-1) > vegetation coverage of 60% (0.50 mm·min-1) > vegetation coverage of 30% (0.29 mm·min-1) during the period of active layer thawing, and vegetation coverage of 60% (0.56 mm·min -1) > vegetation coverage of 30% (0.39 mm·min-1) > vegetation coverage of 92% (0.26 mm·min-1) during the beginning period of active layer freezing. The soil water infiltration rate had a significant difference among slope positions and was closely related to the freezing-thaw cycle, mainly reflected in that the infiltration rate decreased with the slope position downwards; the infiltration rate during the beginning period of freezing was less than that during the thawing period on the same slope position. During the whole infiltration stage, the cumulative infiltration at the slope top was the maximum, showing a better infiltration performance. The environmental factors influencing the infiltration of alpine meadow soil were bulk density, organic matter content and particle size. It was concluded that in the source regions of the Yangtze River the general empirical model f(t)=a+bt-n is more suitable for the period of active layer thawing to study soil water infiltration in alpine meadow in the study area, while the Horton model f(t)=ic+(i0-ic)e-kt is more suitable for the beginning period of active layer freezing.

Key words: Tibetan Plateau, permafrost regions, soil infiltration, freezing-thawing process

中图分类号: 

  • S152.7