盘锦芦苇湿地空气动力学参数动态特征及其影响因素分析

应用盘锦芦苇生态系统观测场的涡度相关通量观测系统和小气候梯度系统的观测资料,估算了芦苇下垫面的空气动力学参数,并分析了其影响因素。结果表明:芦苇湿地零平面位移d和粗糙度Z0的季节变化总体呈现先增加后减少的单峰曲线变化规律。Z0和d均在9月达到最大,分别为0.24 m和1.85 m;12月达到最小,分别为0.03 m和0.02 m。芦苇湿地的Z0和d的季节变化主要受叶面积指数(LAI)、株高(h)及风速的影响。d随h的增加而单调增加,Z0随着h的变化遵循二次曲线,d/h、Z0/h与LAI之间的复相关系数分别为0.99和0.78。研究亦表明,大气稳定度和风向也对d和Z0有一定的影响。

Dynamic characteristics of aerodynamic parameters in Panjin reed wetland and their controlling factors

Based on the data of eddy covariance tower and micrometeorological gradient observation from January to December in 2005,the fundamental aerodynamic parameters including zero-plane displacement(d) and roughness length(Z0) were estimated,and their controlling factors were analyzed in Panjin reed wetland.The results showed that d and Z0 had obvious seasonal variations.The highest values of Z0 and d appeared in September with 0.24 m and 1.85 m,and their lowest values in December with 0.03 m and 0.02 m,respectively.Their seasonal variations were related with vegetation characteristics such as leaf area index(LAI) and canopy height(h) as well as wind speed.d had a close linear relationship with h,and the variations of Z0 with h could be expressed by quadric curves.d/h and Z0/h were nearly correlated with LAI,and multiple correlation coefficient could be 0.99 and 0.78,respectively.Moreover,the atmospheric stability and wind direction would also affect the aerodynamic parameters.