巢湖流域典型站点的风场特征分析

研究巢湖流域流场特征对于认识该地区热量、水汽交换和水流运动规律具有重要意义。利用2006年合肥、肥东、巢湖、庐江站以及姥山岛自动气象站的风场资料,分析了巢湖流域典型站点的风速和风向变化特征。结果表明,陆面站点年平均风速为2.17m/s,湖面站点风速为2.41m/s。所有站点春夏季风速大于秋冬季,陆上风速具有明显的日变化,白天风速大于夜间,而湖面风速日变化较不显著。陆面站点风向季节变化明显,春夏季以偏南风为主,秋冬季以偏北风为主,春夏季的风向日变化特征较秋冬季明显,湖面站风向没有明显的季节变化。陆面站点不同程度地受到湖陆风的影响,距离湖面较近的站点受到的影响较大。湖面和陆面站点风向差距平与气温差距平的日变化保持一致,表明湖陆温差是影响巢湖流域湖陆风的关键因子。

Analysis on wind characteristics at typical sites over Chaohu Lake basin

To understand the regional heat and water vapor exchange and the flow motion law in Chaohu Lake basin,it is important to study the wind characteristics.The wind and temperature characteristics are analyzed based on the data from automatic weather stations at Hefei,Feidong,Chaohu,Lujiang and Laoshan Island in 2006.Results show that the annual average wind speed of Chaohu Lake basin is 2.17 m/s on land and 2.41 m/s over the lake.Wind speed in spring and summer is larger than that in autumn and winter both on land and over the lake.Wind speed in the daytime is larger than that at night on land,but the diurnal variation of wind speed over the lake is less noticeable.The wind direction on land is from the south in spring and summer,and from the north in autumn and winter,showing a significant seasonal variation.Diurnal variation of wind direction on land in spring and summer is more noticeable than that in autumn and winter.Seasonal variation over the lake was not pronounced.The longer the distance between the lake and the station is,the less the lake-land breeze affects the station.Anomaly of wind direction differences between stations on land and Laoshan Island station and anomaly of temperature differences have consistent diurnal variation,which indicates that the temperature difference is the key factor to influence the lake-land breeze over Chaohu Lake basin.