1981-2013年宝鸡市雾霾日数变化趋势及突变分析

Trend and mutation analysis of the number of fogand haze days in Baoji during 1981-2013

目的分析1981-2013年33a宝鸡市雾霾日数变化趋势及突变。方法收集宝鸡市1981-2013年气象站观测的雾霾日数数据,采用趋势系数、倾向率、一元线性回归、距平百分率、MannKendall突变检验和滑动t检验方法分析研究。结果与结论①在33a间,宝鸡市雾霾日数以16.253d/10a的趋势下降,且存在15a和24a的周期动荡;②冬季雾霾发生频率最高,春季略低,其次秋季,夏季最低;③1981-2013年7月份雾霾日数距平百分率波动范围最大,表明在33a内雾霾日数同期波动较为剧烈,且出现极端雾霾现象,9和10月略低,4、5、6和8月次之,2和3月较1月波动范围大,1月波动范围最小;④1981-2013雾霾日数在年、季都有明显的突变趋势,其突变类型表现不同。

Objective—To analyze the trend and mutation of the number of fog and haze days in Baoji during 1981-2013.Methods—Such methods as trend coefficient,tendency rate,linear regression analysis,percentage of precipitation anomalies,Mann-Kendall mutation test and sliding t-test were used to analyze the collected meteorological data of the number of fog and haze days in Baoji from1981 to 2013.Results and Conclusion—1 During the 33 years,the number of fog and haze days in Baoji declined in the trend of 16.253 d/10a,and there was a cyclical turbulence of 15 and 24years.2 The frequency of fog and haze weather was the highest in winter,slight lower in spring,then in autumn,and the lowest in summer.3 The monthly percentage variation of the fog and haze days referring to the average number has the maximum range during the Julys in 1981-2013,which shows the number of fog and haze days within the 33 years fluctuates more violently in Julys when there occurred the phenomena of extreme fog and haze.The percentage variation fluctuates less violently in September and October,and still less violently in April,May,Jun and August,and much less violently in February and March and the least violently in January,which shows the number of fog and haze days during the 33 years fluctuates a little in January.4 The number of fog and haze days from 1981 to 2013 had obvious mutation trends in a single year and a single season,whose mutation types are different.