1960-2008年吉林省降水量的时空演变特征

利用吉林省及其附近区域38个气象站点的年降水资料,通过离差系数、气候倾向率、REOF分析、Morlet小波分析、Mann-Kendall突变检验等方法分析了吉林省降水量的时空演变特征。结果表明,1960-2008年吉林省的年降水量为300~950mm,具有自东南部向东北部、中西部地区逐渐减少的空间变化特征;吉林省有90%以上区域的降水量呈下降趋势,而降水量增加的区域主要分布在汪清、罗子河、靖宇、桦甸等站点附近,约占全省总面积的10%;经REOF分析可以将吉林省降水量的空间结构分为4个具有较高相关性的区域,它们分别是东南部地区、西部地区、东北部地区及中部地区。通化、通榆、罗子河、蛟河4个典型站点的降水量均存在明显的周期性振荡规律,第1主周期依次是9a、23a、25a、19a;Mann-Kendall突变检验结果表明,通化、通榆站分别在1975年、1998年发生了一次减少突变,而罗子河、蛟河站没有发生突变。

Spatial-temporal Precipitation Variation over Jilin Province during 1960-2008

Based on annual precipitation data of 38 meteorological stations in Jilin province and the vicinity area,spatial-temporal characteristics of precipitation over Jilin province during 1960-2008 was analyzed by using deviation coefficient,climate inclination rate,REOF analysis,Morlet wavelet analysis and Mann-Kendall mutation test method.The results showed that multi-annual average precipitation in Jilin province was 300~950mm,with a spatial decreasing tendency from southeast to northeast and central-western.Precipitation decreased during the last 50 years more than 90% area of Jilin province,except for in Wangqing,Luozihe,Jingyu,Huadian stations.Based on REOF analysis,spatial structure of precipitation in Jilin province was divided into 4 highly correlated anomaly regions i.e.the southeast,the western,the northeast and the central region.4 typical stations such as Tonghua,Tongyu,Luozihe and Jiaohe showed obvious periodic oscillations,and the first primary periodic for each station was 9,23,25 and 19 years.Mutation analysis derived from Mann-Kendall test indicated that Tonghua and Tongyu station had significant mutation points in 1975 and 1998 respectively,and both the two mutation points were demarcation points between humid period and drought period,while Luozihe and Jiaohe showed no mutation point during last 50 years.