摘要
基于2011—2012年黄土高原农牧交错带稀疏自然植被生态系统的地表能量通量以及气象数据,对该地区能量平衡各分量(净辐射、感热、潜热和土壤热通量)以及波文比进行日、季节动态的特征分析,研究了潜热通量和感热通量对不同强度降雨事件响应程度的差异,并分析了潜热通量和感热通量的主控因子.结果表明:该地区净辐射、感热、潜热和土壤热通量的日、季节动态曲线均为单峰型曲线,净辐射、感热通量、潜热通量和土壤热通量的年平均值分别为78.19、33.32、24.91和2.65 W·m-2.在全年能量收支平衡中,感热通量占净辐射的43%,潜热通量占32%,土壤热通量占3%,表明对于黄土高原农牧交错带自然稀疏灌木生态系统,全年能量主要以感热的形式交换.生长季感热和潜热占净辐射的比例相同(36%);而在非生长季,感热占主导,占净辐射的比例高达54%.潜热通量在强、弱降雨事件发生后明显升高,感热通量则明显下降.潜热通量与净辐射、水汽压差及植被参数均显著相关,感热通量与净辐射及空气温度梯度显著相关.
Based on the energy flux and meteorological data during 2011-2012 over a sparse shrub- land ecosystem in the farming-pastoral zone of the Loess Plateau, this study investigated the diurnal and seasonal variations of the energy balance components, and discussed the responses of the latent and sensible heat fluxes to different intensities of rainfall events. In addition, we identified the major environmental controlling factors on latent and sensible heat fluxes via correlation analysis. The re- sults showed that the diurnal and seasonal variations of net radiation （ R, ） , sensible heat flux （ H）, latent heat flux （LE） and soil heat flux （G） all showed single-peak curves. The annual mean values of Rn, H, LE and G were 78.19, 33.32, 24.91 and 2.65 W · m-2, respectively. The ratios of ener- gy budget components to net radiation were 43% （ H/R, ）, 32% （ LE/Rn ）, and 3% （ G/R, ）, which indicated that sensible heat flux was the major form of energy loss at this site. In the growing season, the ratios of sensible heat flux and latent heat flux to net radiation were nearly the same （36%） ; while in the non-growing season, sensible heat flux accounted for 54% of net radiation. Latent heat flux increased sharply after heavy and weak rainfall events, while sensible heat flux de- creased sharply at the same time. Continuous rainfall events would lead to fluctuations in latent and sensible heat fluxes. There were significant correlations between latent heat flux and net radiation, vapor pressure deficit and vegetation parameter, while remarkable correlations were found between sensible heat flux and net radiation, and air temperature gradient.
出处
《应用生态学报》
CAS
CSCD
北大核心
2015年第6期1625-1633,共9页
Chinese Journal of Applied Ecology
基金
国家自然科学基金项目(51209117
51139002)
水沙科学与水利水电工程国家重点实验室自主研究课题(2014-KY-04)资助
关键词
能量平衡
潜热通量
感热通量
稀疏灌木
黄土高原
energy balance
sensible heat flux
latent heat flux
sparse shrubland
Loess Plateau.
