1951—2018年南京地区分级降水特征分析

Analysis of graded precipitation characteristics in Nanjing area from 1951 to 2018

为了研究掌握不同等级降水的演变规律,合理利用降水资源,更好地服务于社会生产实践,利用南京站1951—2018年逐日降水资料,分析了南京地区不同级别的雨量、雨日的变化特征。结果表明:各级降水的雨量多年平均占比相对均衡,雨日占比变幅较大,随降雨等级增大雨日占比减小;各级降水雨量在年内各月占比不同,且年内各月主导降水因素各不相同;小雨雨日在各月占比均较高,为年内各月雨日变化的主导因素;除小雨表现为显著性减小(99%显著性水平)的变化趋势,其他量级降水均表现为增加的变化趋势,且暴雨增加趋势通过90%显著性检验;暴雨的雨量、雨日年代际变化存在明显的阶梯式增长;小雨、暴雨雨量分别在1952年、2005年附近发生突变,中雨、大雨在1951—2018年无突变发生。

In order to study and master the evolution law of different levels of precipitation,rationally use precipitation resources,and better serve social production practice,based on the daily precipitation data of Nanjing Station from 1951 to 2018,the variation characteristics of rainfall and rainy days at different levels in Nanjing area were analyzed.The results show that:the annual average proportion of precipitation at all levels is relatively balanced,the proportion of rain days varies greatly,and the proportion of heavy rain days decreases with the increase of rainfall levels;the proportion of precipitation at all levels are different in each month of the year,and the dominant precipitation factors are different in each month of the year;the proportion of light rain days in each month is higher,which is the dominant factor of the variation of monthly rain days in the year;except for light rain,which showed a significant decrease(99% significance level),precipitation of other magnitudes showed an increasing trend,and the increasing trend of heavy rain passed the 90% significance test;the decadal variation of rainfall volume and rain days of heavy rainfall has obvious stepped growth;the rainfall of light rain and heavy rain had abrupt changes around 1952 and 2005,respectively,while moderate rain and heavy rain had no abrupt changes from 1951 to 2018.