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作 者 ：张杰,黄建平,张强

期 刊 ：生态学报 2010年 30卷 11期 页码：2819~2827

关键词：稀疏植被；空气动力学粗糙度；风速；LAI；植株密度；空气动力学模型；

Keywords:sparse vegetation, aerodynamic roughness length, wind speed, LAI, vegetation density, aerodynamic model,

摘 要 ：应用中国西北半干旱区定西试验站2005年观测资料，估算了典型的稀疏农作物区空气动力学粗糙度，结合空气动力学模型分析了稀疏植被区空气动力学粗糙度的时间变化及其与风速、植株密度的关系，并得出空气动力学粗糙度的参数化方案；结合卫星遥感得到的植被叶面积指数资料，模拟了区域空气动力学粗糙度，得出：（1）空气动力学粗糙度的时间变化与风速变化规律有相反的特点；在稀疏植被区，粗糙单元分布密度对流场有一定影响，随粗糙单元密度的增加,空气动力学粗糙度将逐渐增大。（2）植株高度超过0.2m时，植被高度和植株密度、叶面积指数对空气动力学粗糙度的影响较大，当植株高度低于0.2m时，风速的影响较大。（3）结合遥感反演的叶面积指数，采用空气动力学粗糙度和叶面积指数及风速的关系，反演了空气动力学粗糙度，反演结果空间分布和误差都反映了实际空气动力学粗糙度的特征，证明空气动力学粗糙度遥感参数化比较成功。

Abstract:Based on observed dada in 2005 over Dingxi station in semi-arid region of Northwest China, aerodynamic roughness length is estimated, the temporal variable and the relations with wind speed and vegetation density are also analyzed. Combined with LAI from remote sensing, aerodynamic roughness length is simulated by using aerodynamic model. The results show that:（1）Aerodynamic roughness length is on the contrary to wind speed trend. With vegetation density increasing, roughness length will be increased.（2）The effect of vegetation density and LAI on aerodynamic roughness length is large with individual plant height more than 0.2m, and wind speed effect on aerodynamic roughness length is large when individual plant height is less than 0.2m. (3)The relation and the model of aerodynamic roughness length with LAI, vegetation density and wind speed is put forward by combining with LAI from remote sensing, the model can reflect real status, and equivalent vegetation density is presented by using LAI in the model, which is an available means to parameterize aerodynamic roughness length from remote sensing.

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