清远市冬季气温和寒害的变化特征

Variation Characteristics of the Winter Temperature and Cold Damage in Qingyuan

据清远国家气象观测站1957～2010年逐日的气温观测资料,采用趋势分析、Mann-Kendall突变检验和多项式拟合等方法,对清远市的气温和寒害变化特征进行了研究。结果表明,清远市年平均气温升温速率为0.018℃/年,在1998～1999年发生了向暖的突变。冬季气温的升温速率为0.023℃/年,冬季气温变化不稳定性加剧,可能是引发寒害的原因之一。寒害频次和强度在总体变化(线性趋势)上均呈明显减少趋势,主要集中在20世纪60和80年代,寒害强度以中度型为主。

Based on the daily temperature observation from the national meteorological observing station of Qingyuan,trend analysis,Mann-Kendall testing and the polynomial fitting are carried out to investigate the variations of the temperatue and damging cold weaather.Result shows that the annual averaged tempeature of Qingyuan increases at a rate of 0.018℃/year,and a sudden change to the warming trend during the year of 1998～1999;winter temperature increases at 0.023℃/year,and the variation of it is becoming more and mor unstable,which may be one of the reasons for the cold damge.Over all,the frequency and the intensity of the cold damage change on a decreasing trend with an intensively occurring period in the 60 s and 80 s of 20 centuary with medium intensity.