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

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≤U2.0m/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.