黄淮海冬小麦冠层消光系数农业气象数值模拟

Simulation study on the extinction coefficient of winter wheat in Huang-Huai-Hai Plain of China

利用美国Licor-188B辐射量子照度仪测定了黄淮海冬小麦冠层消光系数,建立了冠层消光系数模型,验证表明模型具有较高准确度。数值分析表明,直接辐射消光系数日变化非常明显,散射辐射消光系数日变化幅度较小,总辐射日平均消光系数随纬度增加而增大;当LAI=5时,黄淮海地区冬小麦抽穗期消光系数理论值变化范围为0.6865～0.6969。

Based on the data measured with Licor-188B radiation-quantum-illumination analyzer, a numerical model to simulate the extinction coefficient of winter wheat canopy was established. Validation of the model showed that the model could simulate extinction coefficient fairly well with higher significant levels. Numerical analysis with the model suggest that the extinction coefficient of direct solar radiation is much higher than that of scattered radiation. The daily extinction coefficients of winter wheat canopy are enhanced with latitude increasing with a variation from 0. 6865 to 0. 6969 in Huang-Huai-Hai Plain of China in heading stage.