基于EOF和小波分析的山东省年降水时空变化特征

为了探究山东省年降水量的时空变化特征,根据山东省29个国家基本、基准地面气象观测站1980—2019年逐月降水资料,通过经验正交分解(EOF)、小波分析等方法对山东省年降水量变化特征进行了分析探讨。结果表明:山东省年降水量介于507.0～1 047.4 mm,大体上由东南向西北递减; 山东省年降水场主要具有2种模态,4种表现类型,分别为全省多雨型,全省少雨型,东南部降水偏多、西北部降水偏少型以及东南部降水偏少、西北部降水偏多型,山东省40 a来降水场表现出4种类型的年份数分别为12,12,2,4 a,4种降水类型分布年份实况验证的准确率达到96.7%; 山东省年降水量存在3～9 a的年际变化周期,以及15～32 a的年代际变化周期,其中主周期为28,18,4,7 a,分别经历了大约2,3,15,8.5个丰—枯转换期。综上,山东省年降水量由东南逐渐向西北递减。年降水场具有2种模态,4种表现类型,且具备多时间尺度周期特征。

Characteristics of Spatiotemporal Variation of Annual Precipitation in Shandong Province Based on EOF and Wavelet Analysis

To explore the temporal and spatial variation characteristics of annual precipitation in Shandong Province,based on the monthly precipitation data of 29 national basic and benchmark surface meteorological stations in Shandong Province from 1980 to 2019,the variation characteristics of annual precipitation in Shandong Province were analyzed and discussed by means of empirical orthogonal decomposition(EOF)and wavelet analysis.The results showed that:the annual precipitation in Shandong Province ranged from 507.0 mm to 1047.4 mm,and decreased from southeast to northwest in general;the annual precipitation field in Shandong Province mainly had 2 modes,there were 4 types of precipitation in Shandong Province,which were rainy in the whole province,less rainy in the whole province,more precipitation in the southeast,less precipitation in the northwest,and less precipitation in the southeast and more precipitation in the northwest;the number of years of 4 types of precipitation fields in Shandong Province in the past 40 years was 12 years,12 years,2 years and 4 years,respectively;the accuracy of the actual verification of the 4 types of precipitation distribution years was 96.7%;there were 3~9 years of annual variation period of annual precipitation in Shandong Province,and the interval of 15~32 years;the main periods were 28 years,18 years,4 years and 7 years,which had experienced about 2,3,15 and 8.5 wet-dry transition periods,respectively.The annual precipitation in Shandong Province gradually decreased from southeast to northwest.The annual precipitation field had 2 modes and 4 performance types,and had the characteristics of multi time scale cycle.