黔东南州近10年凝冻特征及灾害风险区划分析

Analysis of Freezing Characteristics and Disaster Risk Zoning in Qiandongnan Prefecture in Recent 10 Years

文章选用2011~2020年黔东南州16个国家气象站和500个区域自动站12月~次年2月的气温、降水、相对湿度、雨凇等逐日观测资料,运用模糊信息分配法找出黔东南地区发生凝冻时的气象要素阈值,结合地理信息系统技术GIS,利用实际观测发生雨凇日数、过程发生频次、过程平均最低气温、最长持续天数4个指标来界定实际发生凝冻的等级并进行风险区划。结果表明:判断黔东南地区形成凝冻天气的标准为日平均气温≤1.0℃、日最高气温≤4.0℃、日最低气温≤0℃、相对湿度≥80%,利用该阈值去寻找满足上述条件区域站发生凝冻的日数,建立凝冻时间序列,最后将凝冻划分为高、较高、中、低4个风险等级。According to the daily observation data of temperature, precipitation, relative humidity, rime, etc., from December to February of the following year at 16 national weather stations and 500 regional automatic stations in Qiandongnan Prefecture from 2011 to 2020, this paper uses fuzzy information distribution method to find threshold values of meteorological elements when freezing occurs in Qiandongnan Prefecture, combined with GIS, four indicators are used to define the actual freezing level and carry out risk zoning, including actual observation days of rime, frequency of process occurrence, average minimum temperature of the process, and maximum duration of the process. The results show that the criteria for judging the formation of freezing weather in Qiandongnan Prefecture are daily average temperature ≤ 1.0˚C, daily maximum temperature ≤ 4.0˚C, daily minimum temperature ≤ 0˚C, and relative humidity ≥ 80%. This paper uses this threshold to find the number of days when freezing occurs in the regional station that meets the above conditions, establishes the freezing time sequence, and finally divides the freezing into four risk levels: high, relatively high, medium, and low.