Spatiotemporal variation characteristics of snowstorm and assessment level of snowstorm process in Jilin Province from 1971 to 2020

Based on the data of daily precipitation,snow depth,extreme wind speed,maximum wind speed and minimum temperature of 55 national meteorological observation stations in Jilin Province from 1971 to 2020,then wavelet analysis,Mann-Kendall(M-K) mutation test,sliding T test and other methods were used to study and analyze the spatiotemporal variation characteristics of snowstorms in Jilin Province; the index of snowstorm process was established by grey correlation method,and divided to get the subregion’s assessment level index of snowstorm process in Jilin Province and validated.The results show that,the snowstorms in Jilin Province are mainly concentrated in November,then March,and both snowstorm stations and accumulated snowstorm amount show a significant steady upward trend,the increase rate is faster after 2006,and the most frequent is in the 2011-2020s; both snowstorm stations and accumulated snowstorm amount show a significant periodic change of 3a in 2000-2016; snowstorm stations change abruptly in 1987,and the average annual of snowstorm stations rose by 15.7 after the mutation; snowstorm stations and accumulated snowstorm amount both show a gradual increase in distribution from plain region to mountainous region; the snowstorm processes in the southeastern region are significantly more than that in the central and western regions,and the extra strong snowstorm processes are mostly distributed in the southeastern region; the subregional assessment level index of snowstorm process can reflect the comprehensive influence degree of snowstorm process in Jilin Province,which is of great significance to improve the ability of disaster prevention and mitigation in Northeast China and deal with extreme disastrous weather.