江淮及苏南地区梅雨特征分析与比较

Analysis and comparison on plum rain characteristics within Yangtze-Huaihe Region and South Jiangsu Area

基于江苏省68个雨量站61年（1954 ～2014年）梅雨期和梅雨量资料进行统计分析,探讨了江淮之间和苏南地区梅雨特征规律.结果表明：（1）江淮之间和苏南地区的多年平均梅雨期为23 d,最长45 d,最短3d,总体均呈延长趋势.（2）入梅时间南部地区早北部地区迟,总体相差不大.（3）入、出梅日期存在明显的年际变化,近似不规则的正弦波变化,近60年入梅总体有先提前又推迟的趋势;出梅总体呈推迟趋势且1970年代中期以前出梅时间显著早于近30年.（4）两区多年平均梅雨量相当,5年和10年一遇重现期梅雨量基本一致,20年及以上重现期江淮之间梅雨量显著高于苏南.

Based on the statistical analysis made on the data of the periods of plum rain and the amount of plum rain obtained from 68 rain-gauge stations in Jiangsu Province within a period of 61 years（ 1954 -2014）, the characteristics of the plum rains within the area among theYangtze-Huaihe Region and the South Jiangsu Area are discussed herein The result shows that ： （ 1 ） the annual average plum rain period within the area among angtze-Huaihe Region and the South Jiangsu Area is 23d with the longest of 45d and the shortest os 3d, which shows a prolonged tendency in general. （2）for the date of the set-in of plum rain period, the southern area is earlyer than that of the northern area and no large difference is there generally. （3） obvious inter-annual variations are there for both the dates of the set-in of plum rain period and the ending of plum rain season with the approximately irregular variations of sinusoidal wave, while the date of the set-in of plum rain shows a trend of shifting to an earlier date and then postponing later in the recent 60 years. The date of ending of plum rain season presents a gerneral postponing tendency, for which the ending date before the mid 1970s is obviously earler than the recent 30 years. （g）the annum averge amounts of plum rain in both the regions are almost the same, while the amounts of the plum rains of 5-year and 10-year return periods are basically identical and the amount of the plum rain with the return period of 20 years or more in the area among the Yangtze-Huaihe Region is obviously larger than that in the South Jiangsu Area.