三江源区退化高寒草甸蒸散的变化特征

发布时间：2018-02-13 15:36

本文关键词： 蒸散降水涡度相关净辐射青藏高原　出处：《草地学报》2017年02期 　论文类型：期刊论文

【摘要】：为揭示三江源区退化高寒草甸水分收支变化特征,利用涡度相关和微气象方法对青海省果洛州大武镇退化高寒草甸生态系统的年蒸散变化进行了定量研究,并探讨了环境和生物因子对其影响。结果表明:年总蒸散量为481.9mm,年蒸散量约占年降水量的97%。生长季中日均蒸散量为2.3mm·d-1,而非生长季日均蒸散量仅为0.6mm·d-1。温度与蒸散量呈明显的指数关系;该区接收的太阳辐射较强,但净辐射占太阳辐射的比例相对较低(46%),在非冻土时期,蒸散量与净辐射呈线性关系;研究区降水量相对丰沛,与温度和净辐射相比,土壤含水量对蒸散的影响相对较小。本研究说明高寒草甸的退化加剧了生态系统的蒸散量,从而降低了生态系统涵养水分的能力,净辐射和温度是驱动三江源区退化高寒草甸生态系统蒸散最主要的环境因子。
[Abstract]:In order to reveal the variation characteristics of water budget of degraded alpine meadow in the source area of three rivers, the annual evapotranspiration of degraded alpine meadow ecosystem in Dawu Town, Guoluozhou, Qinghai Province was studied quantitatively by using vorticity correlation and micrometeorological method. The effects of environment and biological factors on the evapotranspiration were discussed. The results showed that the total annual evapotranspiration was 481.9 mm, and the annual evapotranspiration accounted for 97% of the annual precipitation. The average daily evapotranspiration in growing season was 2.3 mm 路d ~ (-1), while that in non-growing season was only 0.6 mm 路d ~ (-1). The temperature and evapotranspiration were only 0.6 mm 路d ~ (-1). There is an obvious exponential relationship; The solar radiation received in this area is stronger, but the ratio of net radiation to solar radiation is relatively low. In the non-frozen soil period, the evapotranspiration is linearly related to the net radiation, and the precipitation in the study area is relatively abundant, compared with temperature and net radiation. The effect of soil water content on evapotranspiration is relatively small. This study shows that the degradation of alpine meadow exacerbates the evapotranspiration of ecosystem and reduces the ability of ecosystem to conserve water. Net radiation and temperature are the main environmental factors driving the evapotranspiration of degraded alpine meadow ecosystem.
【作者单位】：南开大学生命科学学院;水利部水资源管理中心;中国科学院西北高原生物研究所;
【基金】：国家自然科学基金委项目(31570478) 国家重点研发计划(2016YFC0501905)资助
【分类号】：S812

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