1970—2019年内蒙古大兴安岭林区降雪特征分析

基于1970—2019年内蒙古大兴安岭林区11个气象站逐日降水量和温度资料, 提取降雪数据, 采用趋势分析法、距平法、M-K突变法、滑动t检验法等, 分析了大兴安岭林区降雪的时空变化特征。结果表明: 大兴安岭林区总降雪量和各等级降雪量均呈增加趋势, 其中小雪和暴雪的降雪量增加趋势较小; 小雪和中雪量在21世纪00年代达到最大值, 大雪和暴雪量在21世纪10年代达到最大值; 各等级降雪量对总降水量的贡献率为小雪>中雪>大雪>暴雪; 各等级降雪量年内月变化均呈M型分布, 总降雪量高峰出现在11月; 总降雪量在1995年有显著突变, 小雪、中雪、大雪、暴雪降雪量无显著突变年份。空间上总降雪量和各等级降雪量(除暴雪外)大体呈北多南少、西多东少的变化趋势。大兴安岭林区降雪初始日呈延后趋势, 终止日呈提前趋势, 雪季长度呈每10 a缩短2.3 d的趋势。

Characteristics of snowfall events in Daxing'anling forest region from 1970 to 2019 in Inner Mongolia Autonomous Region

Based on the daily precipitation and temperature data of eleven meteorological stations in Daxing'anling forest region in Inner Mongolia Autonomous Region from 1970 to 2019, the spatial and temporal variation characteristics of snowfall in this region were analyzed using trend analysis method, anomaly method, M-K mutation method and sliding t-test method after extracting the snowfall data.The results show that the total snowfall and all grades of snowfall indicate an increasing trend in the Daxing 'anling forest region, and the increasing trends of light snow and heavy snow were small.The amounts of light and moderate snow reach the maximum in the 2000s, and the amounts of heavy snow and snowstorm reach the maximum in the 2010s.The contribution rate of snowfall in each grade to the total precipitation is as follows: light snow>moderate snow>heavy snow>snowstorm.The monthly variation of snowfall in all grades shows an "M" shape, and the peak value of total snowfall occurs in November.In terms of mutation, the total snowfall has a significant mutation in 1995, while the snowfall of light snow, moderate snow, heavy snow, and heavy snow has no significant mutation.In space, the total snowfall and the snowfall of each grade (except snowstorms) generally show a trend, with more in the north and less in the south, more in the west, and less in the east.In the forest area, the beginning day of snowfall is delayed, and the end day is advanced.The length of the snow season is shortened by 2.3 days every 10 years.