Aerodynamic parameters and their affecting factors over Panjin reed wetland.
应用盘锦芦苇生态系统观测场的涡动相关通量和小气候梯度系统的观测资料,采用涡动相关与小气候梯度观测相结合的方法估算了研究区芦苇下垫面空气动力学参数,并分析了其影响因素.结果表明:该方法可较好地估算芦苇湿地的空气动力学参数;芦苇湿地零平面位移(d)和粗糙度(z0)的季节变化均呈先增后减的单峰曲线变化. z0和d均在9月达到最大,分别为0.24和1.85 m; 12月达最小,分别为0.03和0.02 m.芦苇湿地z0和d的季节变化主要受株高(h)和叶面积指数(LAI)的影响. d随h的增加而线性增加,z0与h呈二次曲线关系.d/h和z0/h均与LAI呈幂函数关系,复相关系数分别为0.99和0.78.
Based on the observation data from eddy covariance tower and meteorological gradient tower in Panjin reed wetland observation plot, and by the method combined eddy covariance with microclimate gradient observation, two fundamental aerodynamic parameters, i.e., zero-plane displacement (d) and roughness length (z0 ), were evaluated, with their affecting factors analyzed. The results showed that the method adopted was suitable for estimating the aerodynamic parameters. There existed obvious seasonal variations in d and z0, with the maximum (1.85 and 0.24 m) in September and the minimum (0.02 and 0.03 m) in December, respectively. The seasonal variations were closely related to vegetation characteristics, plant height (h) and leaf area index (LAI). There was a close linear relationship between d and h, and a conic relationship between z0 and h. Both d/h and d/z0 had power relationships with LAI, and the R2 values were 0.99 and 0.78, respectively.