李黎黎

摘要利用1953～2014年安康市逐日降水量资料，采用数理统计方法，对年降水量、暴雨日数的年代际和季节变化进行分析，研究近62年来安康市暴雨变化特征。结果表明，1953～2014年安康市年降水量总体上呈波动变化，降水量的年际、年内变化差异较大；安康市年降水量与暴雨日数之间存在明显的正相关；62年间共发生暴雨97 d，其中以夏季为主，其次为秋季、春季，冬季没有暴雨发生；大暴雨均发生在夏季；安康市发生暴雨日数最多的是7月，其次为8、9、6、10、5月；降水对汉江流域安康段有明显的影响，该段汛期发生在5～10月，主汛期为7～9月。

关键词降水量；暴雨日数；变化规律；安康市

中图分类号S161.6文献标识码A文章编号0517-6611（2016）04-245-02

Rainstorm Occurrence Regularity in Ankang City in Recent 62 Years

LI Lili（Ankang University，Ankang，Shaanxi 725000）

AbstractAccording to the daily precipitation of Ankang City in 1953-2014，the interdecade and seasonal change of precipitation and rainstorm days were analyzed.Rainstorm change characteristics in Ankang City were researched in recent 62 years.Results showed that the precipitation in Ankang City showed fluctuation changes in 1953-2014.There were relatively great changes in the interannual and annual changes of precipitation.There was significant positive correlation between precipitation and rainstorm days in Ankang City.The total rainstorm was 97 d in the 62 years.Among them，rainstorm happened more in summer，followed with summer and spring.There were no rainstorms in winter.The big rainstorm all happened in summer.And July had the maximum rainstorm days in Ankang City，followed with August，September，June，October and May.Precipitation showed no significant impacts on Ankang in Hanjiang river valley.Its flood season appeared from May to October； and the major flood period was from July to September.

Key wordsPrecipitation； Rainstorm days； Change regularity； Ankang City

在全球气候变化的影响下，全球以及局部地區极端降水事件频发，降水时空分布呈现出明显不均衡。有研究指出，我国年降水量呈减少趋势[1-3]；西部降水量增长趋势较为明显，相对于多年平均值，西部降水量仍然偏低；西北地区降水呈现出非周期性振荡；西北地区东部暴雨发生频率最高，6～9月暴雨发生的概率最大[4-6]。南水北调是解决我国水资源分布不均的跨流域调水工程。汉江上游是南水北调中线工程的水源区，该区暴雨特征、年降水量变化均将会影响到该工程的正常供水。因此，汉江流域研究备受关注。不少学者对陕西省及汉江上游气候、水文演变以及暴雨洪水发生规律进行研究，结果发现，汉江流域汛期径流减少[7-10]；汉江流域洪涝灾害明显增多，安康气候有明显的暖干化现象[10-13]。……