21世纪以来四川强对流天气特征分析

Analysis on Severe Convective Weather Since the 2000s in Sichuan

针对近年来各种强对流天气频发的特点，本文利用气象整编资料、加密自动站资料和灾情直报信息等资料，统计分析了21世纪以来四川的大风、冰雹和强降水等强对流天气的逐月分布和区域分布特征，分析表明：（I）四川强降水年平均分布特征是盆地多于高原，夜间多于白天，夜间主要存在以雅安为中心的四川盆地西南部、以平昌为中心的四川盆地东北部、以北川为中心的盆地西部、以会理为中心的川西高原南部和以雅江为中心的川西高原中部5个高频中心，白天强降水只存在以万源为中心的四川盆地东北部1个高频区。强降水天气主要发生5～9月；（2）四川大风的区域分布呈现出川西高原多四川盆地少的特征，川西高原地区存在着以甘孜为中心的川西高原北部大风高频区和以德昌为中心的川西高原南部大风高频区，四川盆地内存在着以盐亭和广元为中心的四川盆地北部和以井研为中心的盆地南部大风高频区。盆地大风主要出现在4～8月，川西高原大风主要出现在1—6月；（3）四川冰雹的区域分布同样呈现出川西高原多于四川盆地的特征，在川西高原地区存在着以石渠为中心的川西高原北部和以昭觉为中心的川西高原南部冰雹高频区。在四川盆地内存在着以南江为中心的四川盆地北部和以古蔺为中心的盆地东南部冰雹高频区。盆地冰雹主要发生在4～8月，川西高原冰雹主要出现在4～9月。

Statistical analysis was conducted on the monthly features and regional features of heavy precipitation, gale and hail since the 2000s in Sichuan using meteorological information, automatic weather station data encryption and disaster information. The result shows that：i） The average distribution of heavy precipitation in Sichuan is characterized by more precipitation in the basin than in the plateau, more at night than during the day. There are five high frequncy centers at night in the province, which are Ya＇an in the southwestern Sichuan Basin, Pingchang in the northeastern Sichuan Basin, Beichuan in the western Sichuan Basin, Huili in the southern Plateau and Yajiang in the central plateau. While during the days, there is only one high frequency area in Wanyuan in the north - east of Sichuan Basin. The heavy precipitation weather usually occurred from May to September;ii） Gale in Sichuan occurred more frequently in the plateau than in the basin, there existed high frenquncy centres in Ganzi in the western Plateau , Dechang in the southern Plateau,Yanting and Guangyuan in the western Sichuan Basin and Jingyan in the southern Sichuan Basin. Gale usually occurred from April to August in the basin, from January to June in the plateau;iii） Hail distribution also has a similar characteristic with more hails occurred in the Plateau than in the Basin, high frequency centers mainly appear in Shiqu in the western Plateau , Zhaojue in the southern Plateau, Nanjiang in the northern Sichuan Basin and Gulan in the south - eastern Sichuan Basin. Hail usually occurs from April to August in the basin, from April to September in the Plateau respectively.