大连地区近40年风的变化趋势分析

Trend of Mean Wind Speed in Dalian Area in Recent 40 Years

基于大连地区7个气象站点1977—2016年月平均风速和最大风速日值资料,将风速变化趋势的性质和幅度分别用趋势系数和变化速率来表示,并利用时间与变量之间的相关系数对变化趋势进行显著性检验,分析1977—2016年近40年的风速的变化特征。结果表明,大连地区大风天气有明显的季节变化特点,冬春季最多,秋季次之,夏季最少;大于8级偏北大风主要出现在9月至翌年3月;秋冬季以北风及偏北风为主,夏春季以南风及偏南风为主;近40年来,大连地区年平均风速呈明显下降趋势,其递减速率为0.16 m/(s·5年),该地区四季平均风速均呈减少趋势且减少速率相同;年平均气温与年平均风速具有较好的线性关系,呈显著反相关,相关系数为-0.235 41,显然气温的升高是风速减少的主要原因。

Based on the monthly everage wind and the daily maximum wind data in Dalian area from 1977 to 2016,the variation characteristics of wind from 1977 to 2016 nearly 40 years were analyzed by using the method of through the correlation coefficients between time and variables to test the trend by significance test.The results showed that the wind in Dalian area appeared to have an obvious seasonal characterisitic,winter and spring>autumn>summer.8 grade wind or more of North-wind mostly appeared from September to the next March.In autumn and winter,controlled by partial-north wind direction,and in Summer and Spring,controlled by partial-south wind direction.In recent 40 years,the wind speed generally showed a significant decreasing trend in Dalian area,the decreasing rate was 0.16 m/(s·5 a),the seasonal average wind speed showed a decreasing trend as the same rate in this area.The annual mean temperature and annual mean wind speed presented a well linear relationship,which showed a significant inverse correlation with the a-0.235 41 correlation coefficient.Obviously the main affecting factor of wind speed decreased was temperature rising.