用光合-蒸散耦合模型模拟冬小麦水热通量的日变化

从SPAC理论出发，建立了一个冬小麦光合和蒸散的耦合模型．感热通量和潜热通量采用Shuttleworth-Wallace的双层模型计算，并通过冠层阻力的参数化，将光合作用与蒸腾作用耦合起来．用涡度相关方法，观测了感热通量和潜热通量，对模型进行了验证．结果表明，模拟值与观测值比较一致，模型可以很好地模拟感热通量和潜热通量的日变化过程．对模型的敏感性分析发现，冬小麦蒸腾比较敏感的参数有凋萎点、气孔导度参数、叶对红外辐射的反射率和光响应曲线凸度；土壤蒸发只对土壤阻力参数的敏感性较强．本模型对水热通量与环境因子作用过程的理论研究和指导农田的灌溉制度等有一定的意义．

Diurnal variation of winter wheat water and heat fluxes of a simulation with photosynthesis-evapotranspiration coupled model

A coupled model of winter wheat photosynthesis-evapotranspiration was established based on SPAC theory.Sensible heat and latent heat fluxes were calculated by two-layer model proposed by Shuttle worth and Wallace,and photosynthesis and evapotranspiration were coupled by the parameterization of canopy resistance.The model was validated with the data measured by eddy covariance method.The results showed that the simulated and observed values were accordant,and the model could simulate the diurnal variation of sensible heat and latent heat fluxes very well.Sensitivity analysis indicated that the sensitive parameters of canopy transpiration were wilting point,stomata conductance,reflectivity of leaves to infrared radiation,and convexity of photosynthesis response to light,while the sensitive parameter of soil evaporation was soil resistance.The model could be used to study the interactions between water and heat fluxes and environmental factors,and to instruct the irrigation scheme in the field.