冬小麦返青后作物腾发量的尺度效应及其转换研究  

Scaling effects and transformation of crop evapotranspiration for winter wheat after reviving

作　　者：蔡甲冰[1,2] 许迪[1,2] 刘钰[1,2] 赵娜娜[1,2] 

机构地区：[1]国家节水灌溉北京工程技术研究中心,北京100048 [2]中国水利水电科学研究院水利研究所,北京100048

出　　处：《水利学报》2010年第7期862-869,共8页Journal of Hydraulic Engineering

基　　金：973计划资助项目(2006CB403405);国家自然科学基金项目(50909098);中国水科院研究专项(节集0906)

摘　　要：本文基于不同空间尺度下观测的田间数据,分析冬小麦返青生育期后微观尺度的作物叶面蒸腾Tr、小区尺度的作物实际腾发量ETa和中尺度的潜热水分通量LE的尺度效应;基于多元线性回归方法,探讨不同空间尺度ET间的转换关系。结果表明,在充分供水条件下作物的ET尺度效应较为明显;作物叶面指数LAI和空气饱和水汽压差VPD是实现ET尺度转换的关键参量。基于Tr和LAI数值可尺度上推ETa,利用ETa和VPD能尺度上推LE,回归方程和各个参量的回归系数具有很强的显著性。但依据Tr和ETa及同时段的LAI、VPD和Rn尺度上推LE的方法却不具备可行性。Estimation of crop evapotranspiration （ET） at various scales can be used to support agricultural water management as well as water resources deployment and control, to realize the reasonable development and efficient use of water resources in agriculture fields. Based on the observed field data at various spatial scales, it was presented in this paper that the ET at various scales is transited and coupled through the multiple linear regression of the data of winter wheat in 3 years, including the crop leaf transpiration （Tr） measured by LI-6400 photosynthesis system, the actual evapotranspiration （ETa） in plot field calculated from weighting lysimeter, and the latent water flux （LE） monitored by eddy covariance system at middle scale. Comparing the results of the calculated daily ET, it shows that the scale effect would be more evident to crops without water stress, and the leaf area index （LAI） and air vapor pressure difference （VPD） are key parameters in transition of ET. The ETa can be reckoned by Tr directly, or considering LAI at the same time, using the regression equations. The LE can be obtained from the values of ETa and VPD, with obvious significance of regression equations and regression coefficients. Otherwise, the regression equations and coefficients may be not so significant to deduce the LE when Tr, ETa, LAI, Rn and VPD are involved at the same time. All regression equations are semi-experimental and should be validated with much more data later on.

关 键 词：冬小麦 叶面蒸腾 实际腾发量 潜热水分通量 尺度效应 尺度转换 

分 类 号：S274.1[农业科学—农业水土工程]