资源科学 ›› 2017, Vol. 39 ›› Issue (2): 263-275.doi: 10.18402/resci.2017.02.09

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青海湖流域不同海拔高度土壤水分时空变化特征

刘磊1(), 李小雁1,2(), 蒋志云1, 魏俊奇1, 南木甲3   

  1. 1. 北京师范大学资源学院,北京 100875
    2. 北京师范大学地表过程与资源生态国家重点实验室,北京 100875
    3. 刚察县青海省三角城种羊场,刚察 812300
  • 收稿日期:2016-04-27 修回日期:2016-09-18 出版日期:2017-02-25 发布日期:2017-02-20
  • 作者简介:

    作者简介:刘磊,男,河南信阳人,硕士生,主要从事生态水文研究。E-mail:lliu526@mail.bnu.edu.cn

  • 基金资助:
    国家自然科学基金重点项目(41130640);教育部“创新团队发展计划”项目(IRT_15R06)

Variation in soil water content along different altitude gradients in the Qinghai Lake Watershed

Lei LIU1(), Xiaoyan LI1,2(), Zhiyun JIANG1, Junqi WEI1, Mujia NAN3   

  1. 1. College of Resources Science and Technology,Beijing Normal University,Beijing 100875,China
    2. State Key Laboratory of Earth Surface Processes and Resource Ecology,Beijing Normal University,Beijing 100875,China
    3. Sanjiaocheng Sheep Breeding Farm,Gangcha 812300,China
  • Received:2016-04-27 Revised:2016-09-18 Online:2017-02-25 Published:2017-02-20

摘要:

在气候变化背景下探讨流域不同海拔高度的土壤水分状况,对于深入认识变化环境下流域水资源特征具有十分重要的意义。本文通过对青海湖流域不同海拔高度的土壤水分采样,探讨了流域土壤水分的时空变化规律,并对生长季流域不同海拔的水分盈亏状况进行了初步分析,结果表明:①流域平均土壤含水量在生长季旺期达到峰值(28.79%),生长季初期(22.81%)和生长季末期(22.91%)相对较低;随海拔的升高,流域土壤含水量不断增加,且在生长季旺期增加最为显著(P<0.01);②经过一个生长季,湖滨3200~3300m海拔范围内土壤水分收支略有亏缺,减少1.24%,3300~3400m和3400~3600m海拔范围内,水分收支基本平衡,分别增加0.54%和-0.57%,3600~3800m海拔范围内,水分收支有所盈余,增加3.69%;流域海拔3800m以上地区为水分盈余区,且该区域对气候变化较为敏感,气温升高一旦导致流域水分收支平衡区向高海拔推进,将会使青海湖流域水分盈余区大面积减小,进而对流域水资源造成严重影响。

关键词: 土壤水分, 海拔梯度, 时空变化, 气候变化, 青海湖流域

Abstract:

Understanding soil water content variation at different altitudes is fundamental to identifying spatial variation in water resources across a watershed,especially under a changing climate. Here,we evaluated spatial and temporal variation in soil water content along different altitude gradients in the Qinghai Lake watershed. With the integrative consideration of temperature,precipitation,evapotranspiration and the normalized difference vegetation index(NDVI)during the growth season,water deficits of areas at different altitudes were explored. We found that the average soil water content(ASWC)during the middle of the growing season was the maximum(28.79%),higher than the beginning and end of the growing season in 2015,22.81% and 22.91,respectively. ASWC increased with altitude during the growing season,and there was a positive correlation between them,particularly in the middle of the growing season(P < 0.01). The analysis of water budget indicated that regions with altitudes of 3200~3300m were water deficit regions in the watershed,with a decrease of 1.24% in soil water after a growing season. Water budgets in regions with altitudes of 3300~3400m and 3400~3600m were almost balanced,which increases of 0.54% and -0.57%,respectively; an increase of 3.69% was identified in regions with altitudes of 3600~3800m. Regions with altitudes higher than 3800m were considered as water supply regions in the Qinghai Lake watershed. However,the water supply regions have been highly vulnerable to climate change and will decrease sharply if climate warming continues. This will influence water resources deeply in the watershed and have critical effects on the basin and its society and ecosystems.

Key words: Soil moisture, elevation gradient, temporal and spatial variation, climate change, Qinghai Lake basin