中文摘要：

根据南京气象站及其周边3个乡村自动气象站2005年逐时风速资料,拟合了风速的概率分布函数,分析表明：南京城、乡地面风速的概率分布均与3参数的韦伯分布吻合度很高,风速概率密度函数（PDF）曲线形状存在明显的城乡差别,城市风速PDF曲线更加陡峻,即风速分布更为集中;在0.75～3.75 m/s,城市风速PDF值明显高于周边乡村,而在〉3.75 m/s和〈0.75 m/s范围,城市风速概率密度值则低于乡村;城市下垫面的摩擦效应削弱风速而热力效应起增强风速作用,对风速的城乡差值序列的分析发现：多数时间城市风速是小于乡村风速的,但风速小于1.90 m/s条件下,城市风速会出现大于乡村的现象;总体上摩擦效应的作用远大于热力效应;城市效应使全年平均风速下降0.43 m/s。

英文摘要：

Based on hourly observations of wind speed at Nanjing station and three automatic weather stations in the surrounding rural area in 2005, the probability distribution function of wind speed is fitted in this study. Analysis indicates that the 3-parameters Weibull distribution well fits the urban-rural surface wind speed distribution, while significant differences can be found in curves of wind speed probability density function（PDF） between urban and rural areas. The curve of wind speed PDF is more precipitous in urban than in rural area, suggesting that the wind speed distribution is more concentrated in urban area. PDF values are significantly higher in urban area than in the surrounding rural area for wind speeds within the range of 0.75-3.75 m/s, but lower for wind speeds beyond this range. Frictional effect generated by urban underlying surface can weaken the wind speed while the urban thermal effect can intensify the wind speed. Analysis of time series of urban-rural wind speed difference indicates that most of the time urban wind speed is smaller than rural wind speed, but larger while the wind speed is lower than 1.9 m/s. The impact of urban surface frictional effect is much greater than that of its thermal effects in general, and urbanization leads to a decrease of 0.43 m/s in annual mean wind speed.