摘要
使用依兰测风塔2010年5月到2011年4月期间10、50、70、100m4层测风数据对依兰风特征进行分析，结果表明：测风塔各高度风速具有一致的日变化规律，均为白天大，夜间小；垂直风速各时刻平均值均为正值，风速上升趋势较下降趋势明显，日变化规律与水平风速基本一致；风廓线指数a值夜间较大且稳定。白天较小；湍流强度随高度升高而减小，各高度日变化趋势基本一致；各高度主导风向一致，随高度增大，主导风向出现频率升高；各高度污染系数最大对应的风向一致，随高度增加，污染系数较小的风向区间增加，越有利于污染物的扩散，增加污染物的排放高度可以有效减少城市近地面的污染物浓度。
Wind gauging data at four elevations of 10, 50, 70 and 100 metres above ground in the period of May 2010 till April 2011 were observed by an anemometer tower to analyse wind characteristics in Yilan. Results have shown that there was a consistent rule of the diurnal variation in wind speed at each elevation, i.e., higher in daytime and lower at night. Average values of vertical wind velocity were all positive, and the increasing trend was more obvious than decreasing trend whilst its diurnal change was basically in accordance with that of horizontal wind velocity. Wind profile index a was greater and steady at night. Turbulence intensity declined along with elevation rising, whilst its diurnal changes at any elevations basically showed no difference in trend. Among various elevations, the prevailing wind directions were consistent, and their occurrence frequency increased along with upward elevation. Wind directions to which the maximum pollution coefficient corresponded were the same at all elevations, and the wind direction intervals with lower pollution coefficient expanded as the elevation going up so as to benefit the diffusion of pollutants. It would be an effective way to reduce pollutant concentration at ground elevation in a city by increasing the height for emission of pollutants.
出处
《上海环境科学》
CAS
2013年第5期216-220,共5页
Shanghai Environmental Sciences
关键词
风特征
风廓线指数
湍流强度
主导风向
污染系数
Wind characteristics Wind profile index Turbulence intensity Prevailing wind direction Pollution coefficient
