1960—2013年白洋淀湿地气候变化特征分析

Characteristics of climate change from 1960 to 2013 in Baiyangdian wetland

利用白洋淀湿地及周边地区的11个气象站观测资料,采用一元线性方程、皮尔逊系数(Person)、变率分析和Morlet小波分析等方法,对1960—2013年白洋淀湿地气温和降水的年变化、四季变化进行了统计分析。结果表明:近54 a白洋淀湿地年及冬季、春季平均气温呈上升的趋势,夏季和秋季平均气温呈下降的趋势,上升和下降的趋势均不明显,且白洋淀湿地气温变化幅度明显低于周边地区,说明湿地气候对气温变化具有一定的减缓作用。春季和秋季降水量呈增加的趋势,年及冬季、夏季降水量呈减少的趋势,变化趋势均不明显,但白洋淀湿地年平均降水量低于周边地区。此外,白洋淀湿地年和四季平均气温在20世纪60年代至2000年左右均存在3 a左右的振荡周期,且年、春季及秋季平均气温还存在5 a左右的振荡周期;年和四季降水在20世纪60年代存在3 a左右的振荡周期,在20世纪80—90年代还存在4 a左右的振荡周期。

Based on observed data at 11 weather stations around the Baiyangdian wetland from 1960 to 2013,variation of annual and seasonal temperature and precipitation was analyzed by methods of a linear equation,a Person coefficient,a rate analysis and a Morlet wavelet analysis.The results showthat annual mean air temperature is in an increasing trend,so is winter and spring temperature.Mean air temperature in summer and autumn is in a decreasing trend.However,increasing and decreasing trends of air temperature are not significant.The amplitudes of air temperature fluctuation are obviously weaker in Baiyangdian than in the surrounding areas.It suggests that microclimate in the wetland significantly modulates climate change.On the other hand,precipitation is in an increasing trend in spring and autumn,while it is in a decreasing trend in winter and summer,so is annual precipitation.All trends are not significant,while annual precipitation is lower in Baiyangdian wetland than in the surrounding areas.Furthermore,there is a 3-year cycle for annual and seasonal air temperature from 1960 s to 2000 in Baiyangdian wetland and a 5-year cycle for annual,spring and autumn air temperature.The cycle is 3 years for annual and seasonal precipitation in 1960 s,and it is 4 years during 1980 s to 1990 s.