赤峰市暴雨时空特征分析

Analysis on the Spatial-Temporal Feature of Rainstorm in Chifeng

利用赤峰市14个国家级观测站自建站至2015年的逐日降水量资料,共统计暴雨过程142次,其中区域暴雨天气过程77次,对其进行时空特征分析.结果表明,暴雨主要出现在4月下旬至10月上旬,集中在6月中旬至8月中旬,7月下旬最多、中旬次之,7月远多于8月,夏季的6~8月最多,秋季略多于春季;65a趋势不明显,1960-1981年为震荡趋势,但基本平直,1982-2011年震荡更加明显,为暴雨多发时段,最大值出现在1986年的12次过程,2012年后震荡减弱,暴雨进入少发阶段;20世纪60-90年代为波动上升趋势,90年代达到峰值,到21世纪的2000年代为下降趋势.空间分布为南部、中部多暴雨,西、西北部和东、东北部少暴雨,在巴林左旗、八里罕站维持两个多暴雨中心,西北部的克什克腾站为少暴雨中心,这种空间分布与地形特征密切相关.

Spatial-temporal feature of rainstorms were analyzed based on the daily precipitation data of 14 national weather stations in Chifeng China since their establishment until 2015. These included 142 rainstorm processes which had 77 regional rainstorms. Rainstorms mainly occurred from late April to early October,concentrated in mid- June to mid-August,and appeared mostly in late July. Slightly more rainstorms occurred in autumn than in the spring. The trend was not obvious for 65a,there was a turbulent trend from 1960 to 1981,but it was basically flat. The volatility was more obvious from 1982 to 2011.The most rainstorms appeared in 1986 and,the volatility weakened and the stage of low incidence occurred after 2012. This demonstrates an increasing tendency from 1960s to 1990s and an descending trend after the 21st century,peaking in the 1990s. As viewed from spatial distribution, heavy rainstorms were distributed in the south and central areas;less rain was distributed in the west,northwest, east and northeast. Two heavy rainstorm centers occurred at Bahrain Left County and Balikun Station,with fewer rainstorms at Kashkent station in the northwest closely relating to the terrain.