南通地区1960-2016年降水集中度和集中期变化讨论

Preliminary Analysis of Concentration and Concentration Period of Precipitation in Nantong Region from 1960 to 2016

选取浙江省1960~2009年50年3~9月50个雨量站的逐日降水资料,运用小波分析方法对研究区的降水集中度(PCD)和集中期(PCP)变化特征进行分析。研究结果表明,南通地区PCD值变化在0.17~0.63之间,PCP值变化于147.2~236.4,说明整个南通地区降水集中度有明显震荡性;降水集中期主要分布在6~8月,最大降水日平均日为7月6日左右,不同年份有较不均匀的偏早或偏晚情况出现;降水集中期的提前或推迟的趋势对应该年降水总量的减少或增加,两者有较好的线性拟合度。南通地区PCD和PCP的主周期都是30年左右,说名南通地区的降水在30年左右会经历一个由较为集中到较为均匀的过程,且最大降水出现的时间在30年左右会经历一个由较晚到较早的过程。进一步检验PCD和PCP值在南通8个站点间的差异性发现,南通各站点的降水集中度和降水集中期主周期较为统一。

Based on the daily precipitation data of 50 rainfall stations in Zhejiang Province from1960 to 2009,the variation characteristics of precipitation concentration(PCD)and concentration period(PCP)were analyzed by wavelet analysis method.The results show that the PCD of Nantong area is higher than that of PCD The change of PCP value is between 0.170.63 and 147.2236.4,which indicates that the precipitation concentration degree in Nantong is obviously oscillatory;the precipitation concentration period mainly distributes from June to August,and the average day of the maximum precipitation is about July 6,and there are uneven early or late situations in different years;the trend of advance or postponement of precipitation concentration period corresponds to the decrease of total annual precipitation Both of them have good linear fitting degree.The main periods of PCD and PCP in Nantong are about 30 years.It is said that the precipitation in Nantong will experience a process from more concentrated to more uniform in about 30 years,and the maximum precipitation will experience a process from later to earlier in about 30 years.Further testing the difference of PCD and PCP values among the eight stations in Nantong,it is found that the precipitation concentration degree and the main period of precipitation concentration period are relatively uniform.