1981—2020年贵州省降雪时空分布特征

利用1981—2020年贵州省降雪日数、初始日期、终止日期资料，分析了贵州降雪的气候特征，以及降雪日数与海拔高度、纬度的关系。结果表明：1） 贵州降雪日数西北多、南少，大值中心位于贵州西北部；降雪日数整体偏少，呈逐渐减小的趋势，2012年为突变点，整体上降雪日数每10 a减少1.6 d。降雪从11月开始出现，持续到次年3月，主要集中在冬季；开始时间集中在08—10时和20—21时；降雪具有明显的间歇性特征，降雪天气过程中仅发生1次降雪的占全部降雪过程的48.1%，主要在贵州南部，持续3 d及以上的过程集中在贵州中北部。2） 降雪初始日期集中在12、1月，最早11月；终止日期集中在2、3月，最晚4月。贵州中北部开始降雪多为12月，终止降雪多为2月；南部初始多为1月，终止降雪多为1—2月。贵州中北部降雪期更长，开始到结束间隔约为60—129 d，而南部大部为40 d以下，全省平均54 d。3） 降雪日数随着海拔高度每升高100 m增加2.3 d，纬度每增加1°增加11.4 d。

Temporal and Spatial Variation Characteristics of Snowfall in Guizhou Province from 1981 to 2020

Based on the data of snowfall days, initial date and end date, the climatic characteristics of snowfall in Guizhou from 1981 to 2020 were analyzed, and the relationships between altitude, latitude and snowfall days were discussed. The results showed that: 1) The snowfall days in Guizhou were more in the northwest and less in the south, and the high values concentrated in the northwest of Guizhou. The number of snowfall days decreased by 1.6 d every 10 years. Snowfall began in November and lasted until March of the next year, mainly occurred in winter. The initial time was concentrated around 08:00 BT -09:00 BT and 20:00 BT-21:00 BT. Snowfall presented obvious intermittent characteristics: the probability of only one snowfall event occurred in a snowfall process accounted for 48.1%, and the high value area mainly appeared in the south of Guizhou, and the snowfall that lasting for more than 3 days were concentrated in the central and north of Guizhou. The number of snowfall days was relatively small as a whole, and the mutation point occurred in 2012. 2) The initial date of snowfall was concentrated in December and January, and the earliest snowfall appeared in November. The termination date was mainly in February and March, and the latest snowfall appeared in April. In the central and northern areas of Guizhou, the snowfall initiated in December and terminated in February. In the southern areas, the snowfall initiated in January and terminated in January to February. The snow period was longer in the middle and north of Guizhou, and the interval from the beginning to the end was about 60-129 d, which was less than 40 d in most southern regions, with an average of 54 d in the whole province. 3) The number of snowfall days increased with the increase of altitude and latitude, which increased by 2.3 d per 100 m and 11.4 d per 1°, respectively.