摘要
内蒙古干旱区是我国高原生态屏障的重要组成部分,其生态环境直接关系我国北方生态安全。为了解研究区生态系统蒸散发分割对于干旱的响应,本研究利用涡度相关数据构建SiB2模型,对植被蒸腾(T)、地表蒸散发(ET)等变量进行模拟,同时分别基于通量站涡度相关数据和SiB2模型模拟计算蒸腾与蒸散发比值(蒸腾比,T/ET)。结合标准化降水蒸散发指数(SPEI),分析研究区不同干湿条件下蒸散发及蒸腾比的变化。结果表明:研究区蒸散发受干旱影响显著,蒸散发量与干旱程度呈负相关,在严重干旱或极端干旱时,干旱对蒸散发的影响滞后时间增长;根据SiB2模型计算的研究区2003—2012年蒸腾比与干旱程度相关性较强,在较为湿润的年份(2003),T/ET达到最高值0.64,表明此时植被蒸腾在陆地蒸散发中占据主导地位;在较为干旱的年份(2005),T/ET值为0.39,表明在干旱胁迫下植被蒸腾减少,土壤蒸发占蒸散发量的主导地位;在持续干旱情况下,T/ET和ET的波动范围均较小,表明植被在干旱情况下能根据外界环境进行自我调节,对维持生态系统稳定有一定的作用。研究结果对于推动区域水资源合理配置、提高干旱区水分利用效率具有一定意义。
The arid zone of Inner Mongolia is an important part of the ecological barriers of plateaus in China,whose ecological environment is directly related to ecological security of northern China.To understand the respon⁃ses of ecosystem evapotranspiration partitioning to drought,a SiB2 model was constructed using eddy covariance data to simulate vegetation transpiration(T)and surface evapotranspiration(ET).The ratio of T/ET was calculat⁃ed based on eddy⁃related data from the flux station and the SiB2 model,respectively.Combined with the drought degree assessment index(SPEI),the changes of ET and T/ET ratio under different dry and wet conditions in the study area were analyzed.The results showed that the ET in the study area was significantly affected by drought,and that there was a negative correlation between ET and drought degree.The lag time of drought effect on ET increased when drought was severe or extremely severe.The T/ET ratios calculated by SiB2 model from 2003 to 2012 was strongly correlated with drought degree.In the humid year(2003),the T/ET ratio reached the highest value of 0.64,indicating that vegetation transpiration played a dominant role in evapotranspiration.In the relatively dry year(2005),T/ET value was 0.39,indicating that vegetation transpiration decreased under drought stress and that soil evaporation played a dominant role in evapotranspiration.In the case of continuous drought,the fluctuation range of T/ET and ET was weak,indicating that vegetation could self⁃regulate under drought,which plays a certain role in maintaining ecosystem stability.The results have significance for promoting rational allocation of regional water resources and improving water use efficiency in arid areas.
作者
李欣悦
薛宝林
王国强
刘俊芳
王立波
刘廷玺
段利民
包玉凤
LI Xinyue;XUE Baolin;WANG Guoqiang;LIU Junfang;WANG Libo;LIU Tingxi;DUAN Limin;BAO Yufeng(College of Water Sciences,Beijing Normal University,Beijing 100875,China;Water Conservancy and Civil Engineering College,Inner Mongolia Agricultural University,Hohhot 010018,China;Tongliao Hydrology Bureau of Inner Mongolia Autonomous Region,Alxa League 750306,Inner Mongolia,China)
出处
《生态学杂志》
CAS
CSCD
北大核心
2023年第11期2806-2816,共11页
Chinese Journal of Ecology
基金
内蒙古自治区科技重大专项(2020ZD0009)资助。
关键词
蒸散发分割
涡度相关
SiB2模型
干旱
evapotranspiration partitioning
eddy covariance technique
SiB2 model
drought
