近42年内蒙古暴雨时空分布特征

Temporal and Spatial Characteristics of Torrential Rain over Inner Mongolia in the Last 42 Years

基于1971-2012年内蒙古地区116站逐日降水资料,利用线性倾向估计、Mann-Kendall突变检验等方法,分析了内蒙古地区暴雨时空分布特征。结果表明,时间变化看,21世纪以来暴雨日减少显著,但暴雨强度却呈现增强趋势;暴雨日存在明显的年代际变化特征,90年代是暴雨多发年代。空间分布看,暴雨发生频率自西向东迅速递增,东部地区是内蒙古暴雨发生频率最高的地区,暴雨最少发生的地区是内蒙古西部地区;大兴安岭山脉东南麓中雨贡献率最大,其余地区小雨贡献率最大,总体上看暴雨贡献率最小。

Based on the daily precipitation of 116 stations from 1971 to 2012 over Inner Mongolia , bymeans of linear trend estimate, Mann- Kendall test method, temporal and spatial characteristics oftorrential rain are analyzed over the whole region . The results suggest that： on the timescale change, thedays of the torrential rain has an obvious decreasing trend especially since the 21th centuries, but theintensity of the torrential rain days has increased to some extent. Characteristics of interdecadal variationof torrential rain days is obvious, the torrential rain occurs frequently in the 1990s. On the spatialdistribution, the occurrence frequency of torrential rain is increasing tendency from the west to the east,the occurrence frequency of torrential rain is the most in the east area and the least in the west area. Thecontribution rate of torrential rain is the most on the southeast of Daxing’an Mountains, the contributionrate of light rain is the most on the other regions, on the whole , the contribution rate of torrential rain isthe least.