贵州年最大小时雨强时空分布变化特征

应用贵州现有自记降水、自动降水观测资料,统计分析了贵州1954—2017年国家气象站累年最大小时雨强、年最大小时雨强的时空分布特征,1968—2017年50年年最大小时雨强变化。结果表明,贵州年最大小时雨强分布于13.6～117.4mm·h~(-1)之间,累年最大小时雨强在53.0～117.4mm·h~(-1)之间。贵州西南部、中西部、东北部,东南部都出现了小时最大雨强100mm·h~(-1)以上的区域,西南部为小时雨强最强区域。贵州强降雨3—11月均有发生,集中出现在5—8月,6月强降雨最多,贵州强降雨具有明显的夜发性特征,出现时间集中于午夜前后2h左右,前半夜多于后半夜,午间时间是出现最少时段。贵州小时雨强增大与减小趋势都不明显,在东南面、南部、西部有弱增大趋势,东北和西北面呈弱减小趋势。

Spatiotemporal Characteristics and Variation Trends of Annual Maximum Rainfall Intensity in Guizhou

Based on the existing data of self recorded and automatic precipitation in Guizhou, the temporal and spatial distribution characteristics of the annual maximum rainfall intensity, the maximum rainfall intensity during 1954-2017 in national meteorological stations in Guizhou, and the variation trends of rain intensity from 1968 to 2017 are statistically analyzed. The results show that the annual rain intensity in Guizhou was between 13.6 mm to 117.4 mm per hour, and the maximum of the years in Guizhou was between 53.0 mm to 117.4 mm per hour. The hourly maximum rainfall intensity in the southwest, midwest, northeast, and southeast areas were all over 100 mm per hour. The southwest had the strongest rainfall intensity. The heavy rainfall in Guizhou occurred from March to November, mainly between May and August, while the heaviest rainfall happened in June. The heavy rainfall in Guizhou was characterized by obvious night occurrence, usually around 02:00 at midnight, more in the first half of the night than in the second half. The occurrence frequency at noontime was the least. The increase/decrease trend of rain intensity in Guizhou was not obvious, with the slight increases in southeast, south and west, and the slight decreases in northeast and northwest.