近63年陕西宝鸡极端强降水事件变化特征诊断

为明确宝鸡市极端强降水事件变化特征,掌握极端降水事件发生规律,以1952-2014年宝鸡气象站点逐日降水量实测值为基础,综合运用气候倾向率、Morlet小波函数、R/S分析法、Mann-Kendall非参数检验法对极端降水变化特征进行诊断分析。结果表明:宝鸡市近63 a来,除年降水总量、强降水量、中雨日数、大雨日数呈波动下降趋势外,其余指数呈现上升趋势,其中以极强降水量变化表现最为剧烈,变率超过1 mm/10a。强降水量和极强降水量呈现大小尺度相互嵌套的周期变化趋势,二者仅存在弱突变;未来宝鸡强降水变化与过去变化趋势一致将呈减少态势,极强降水变化以反向趋势呈减少态势发展。此外,各极端强降水指数与年降水总量、降水强度呈现正相关,年降水的变化可以很好的反映极端降水指数的变化。

Diagnosis of variation characteristics of extreme precipitation event in Baoji for 63 years

In order to reveal the variation characteristics of extreme precipitation event in baoji and master the occurance rule of extreme precipitation event,the paper based on meteorological observation data sets in Baoji from1952 to 2014,and comprehensively applied general linear regression analysis, Morlet wavelet analysis, R/S analysis and Mann Kendall tests to analyze the variation characteristics of extreme precipitation event.The results show that except the annual rainfall,strong rainfall,days of medium precipitation,and days of great precipitation presented the trend of decrease,the other indexes possessed the trend of increase in study area from 1952 to 2014.The change of extreme precipitation is the strongest, the change rate is more than 1mm/10a. The strong precipitation and the extreme precipitation present the trend of nesting periodicity of large and small scales.The both There were only weak mutations between the both.The future trend of strong rainfall in Baoji will be consistent with the trend of the past showed a reduced trend. The trend of extreme precipitation change and past trend is decreasing trend with reverse trend.In addition, all extreme precipitation indice has positive correlation with annual rainfall and rainfall intensity.The change of annual precipitation may best reflect the change of extreme precipitation index.