浙江降水量场时空分布变化的特征

应用EOF方法对浙江省38个气象观测站43年（1961．1～2003．12）的月、季降水量距平场的时空分布变化进行统计分析，结果表明：浙江省降水量场的空间分布主要有南北分布型和东西分布型，春、冬季节以南北分布为主，夏、秋季节以东西分布为主。冬季降水场的空间分布尺度比夏季大；夏季降水场空间分布的年际变化比冬季大。秋季降水场空间分布变化的显著周期为9～14年，冬季降水场空间分布变化的显著周期为3．5～4．7年，而春季和夏季降水场空间分布则无显著周期存在。

On the Characteristics of Time and Spatial Distribution of Precipitation Fields in Zhejiang Province

By means of EOF method the data of monthly and seasonal precipitation collected from the total of 38 meteorological stations in Zhejiang province from Jan 1960 to Dec 2003 are analyzed,It's found that there are two spatial distribution types of precipitation fields,i.e.south-north distribution type whose isohyets almost run parallel with latitudes and east-west distribution type whose isohyets almost parallel with longitudes.The former is dominant in spring and winter,and the latter is prevalent in summer and autumn.Moreover,the spatial distribution scale in winter is larger than that in summer,while the inter-annual variation of spatial distribution in winter is smaller than that in summer.Finally,it's also obtained that the distinct variation period of the precipitation field in autumn is 9 to 14 years and 3.5 to 4.7 years in winter,but there is no remarkable variation periods in spring and summer.