用拉格朗日反演模型模拟长白山森林蒸散  

Simulation of evapotranspiration in broad_leaved and Korean pine mixed forest in Northeast China's Changbaishan Mountain using inverse Lagrangian dispersion analysis

作　　者：刁一伟[1] 王安志[1] 金昌杰[1] 关德新[1] 裴铁璠[1] 

机构地区：[1]中国科学院沈阳应用生态研究所

出　　处：《北京林业大学学报》2005年第6期29-35,共7页Journal of Beijing Forestry University

基　　金：中国科学院知识创新工程项目(YCXZY0203);国家自然科学基金项目(30370293);国家重点基础发展计划研究项目(2002CB111503)

摘　　要：该文以长白山阔叶红松林为研究对象,以Raupach提出的Localized Near Field(LNF)理论为依据,耦合垂直速度标准差σw(z)和拉格朗日时间尺度TL(z),建立林冠内水汽源/汇强度和平均浓度廓线之间的关系;利用拉格朗日反演模型提出了通过林冠水汽浓度梯度计算林冠内的水汽源/汇强度进而推算森林蒸散的方法.模拟结果与开路涡动相关系统的观测数据比较显示:白天水汽累积通量的模拟精度达到81%,模拟值高出实测值约15%～25%;夜间模拟值比实测值高出2～4倍,其原因尚不清楚.观测期内全天水汽总量模拟值298.91 mm,观测值为240.33 mm.最后,讨论了水汽源/汇强度及其通量随时间和高度的演变过程.Quantifying the exchange of water vapor between biosphere and atmosphere requires a detailed understanding of the interaction between canopy structure and local canopy. An inverse Lagrangian dispersion analysis to infer water sources, sinks, and fluxes from measured mean concentration profiles was applied and field-tested in a broad-leaved and Korean pine mixed forest using eddy covariance measurements. The method was based on Localized Near Field（LNF）, which coupled with a standard deviation in vertical velocity σw （z） and a Lagrangian times cale TL （z）. The results showed that the model had good agreement between modeled and measured daily daytime evapotranspiration, with an average precision of 81%, i. e. the modeled results were 15% - 25% higher than that of the measured. Nocturnally, the modeled results were 2-4 times as high as those of the measured, but the reason remained unclear yet. The total calculated evapotranspiration, 298.91 mm, was much higher than the measured result, 240.33 mm. Finally, the variation of the source/sink with time and depth was also discussed.

关 键 词：拉格朗日反演分析 源汇分布 蒸散 

分 类 号：S715.5[农业科学—林学]