2012—2015年内蒙古短时强降水分布特征

Distribution Characteristics of Short-time Heavy Rainfall in Inner Mongolia from 2012 to 2015 Years

利用内蒙古119个国家气象站逐小时降水量及常规的日降水量资料对2012—2015年内蒙古出现的短时强降水及大雨以上天气情况从时空分布、出现概率、降水比率等多方面进行了比较全面的统计。分析了内蒙古短时强降水的时空分布特征,特别是得出了内蒙古短时强降水发生时段,以及短时强降水在整个大到暴雨过程中所占比例等方面的特点,为预报员认识内蒙古短时强降水活动情况提供有利的参考。分析得出:短时强降水在时间、空间以及降水量级上的分布极不均匀,主要发生在6—8月,7月最多;短时强降水主要出现在午后到傍晚时段,集中在15—17时,尤其17时最多;短时强降水多出现在日降水在6h之内(含6h),占短时强降水发生总数的57%;短时强降水的降水比率相当高,有84%的短时强降水过程中短时强降水雨量占当日降水总量的50%以上,39%的占当日降水总量的80%以上;短时强降水受地形增幅影响极大,内蒙古东部偏东的大兴安岭东侧和西中部阴山山脉南侧均为短时强降水多发区。

By using rainfall dataset from 119 observation stations in Inner Mongolia during the period of 2012 to 2015,we have conducted a comprehensive analysis from time and space distribution,occurrence probability,precipitation ratio compares.We have analysised the temporal and spatial distribution of short-time heavy rain of Inner Mongolia,precipitation periods and the short-time strong rainfall proportion in the whole process of heavy rain which provide the beneficial reference for forecasters to know shorttime strong rainfall in Inner Mongolia.The results show that short-time strong rainfall in time,space,and the distributions of the precipitation were highly unhomogeneous.Short-time strong rainfall occurs mainly in June to August,most of in July,and short-time strong rainfall mainly appear in the afternoon to the evening time,concentrated in the 15 pm to 17 pm,most especially 17 pm.The precipitation of short-time strong rainfall occurs in 6 hours(including 6 hours),accounting for 57%of the total precipitation period.There are 84%short-time heavy rainfalls in the process of precipitation of the total amount of precipitation more than 50%of the day,accounting for 39%of the total amount of precipitation more than 80%of the day.Inner Mongolia Eastern Greater Khingan Range East and West Central South of Yinshan Mountains are the main locations of short rainfall,which are affected greatly by the increase in the terrain.