根据病害调查的结果、选择与病害密切相关的９项气象因子为指标；通过对东北地区５２个市县进行聚类分析．将东北地区杨树冰核细菌溃疡病的危险等级划分为重发区、常发区、偶发区和不发区４级．与病害调查的实际情况基本一致。 According to the results of the disease survey, nine meteorological factors closely related to the disease were selected as indexes; 52 cluster cities and counties in Northeast China were clustered. The risk grade of poplar ice nucleation ulcer disease in northeastern China was divided into four levels: recurrence zone, frequent zone, sporadic zone and non-zone zone. The actual situation with the disease survey is basically the same.