溪洛渡水电站坝区地面风场与大气稳定度特征分析

Analysis on the surface wind field and atmospheric stability characteristics in the dam area of Xiluodu hydropower station

利用永善县气象站2004～2008年逐时观测资料,对溪洛渡水电站坝区的地面风场、污染系数以及大气稳定度进行了初步研究.结果表明:①坝区地面风场静小风出现频率高,属于比较典型的小风区域;有风时以E风和NE风为主导风向,以1.0≤U【2.0 m/s风速段出现的频率最高,全年平均风速以东(E)风为最大;②溪洛渡坝区四季及全年受污染最严重的区域均为东北(NE)风的下风向,即坝区SW方位象限区域;③坝区全年及四季中,中性类(D)稳定度占据了主导地位;在有风条件下,不稳定类(A～C)和中性类(D)稳定度条件下主导风向均为东(E)风,而稳定类(E～F)条件下主导风向为东风和南风;三类稳定度条件下都以平均风速为1～2 m/s风速段出现的频率最大.

According to the hourly observation data from 2004 to 2008 of Yongshan weather station,the surface wind field,contamination coefficient and atmospheric stability characteristics in the dam area of Xiluodu hydropower station are analyzed.The results show that ①the wind speed is small in dam area,the prevailing wind directions are East and Northeast when wind speed is equal to or greater than 1.1m/s,the frequency of 1.0≤U<2.0m/s is highest,the annual average wind speed of east wind is maximum;②the area of NE wind's downwind direction is the severity air pollution area in the Xiluodu hydropower station dam area all the year round;③neutral stability play a dominant role all the year round,the prevailing wind directions of unstable and neutral stability are all east wind when wind speed is equal to or greater than 1.1 m/s,while the prevailing wind directions are ease an south wind in the stable type,the frequency of 1～2 m/s wind speed is maximum at three type stability.