一、制尺依据大兴安岭地区从一九六五年至一九七九年其发生八百多起林火,根据发生林火时的风速、温度和雨后天数发火率的统计材料和实地测定林火发生时地被物含水率,确定出影响林火发生发展的主要因子及其所占比例。二、制尺方法把影响林火发生的四个主要因子〈风 Based on the statistics of more than 800 forest fires in the Greater Hinggan Mountains from 1965 to 1979, based on the statistical data on the wind speed, temperature and number of days after the rain, as well as field measurements of forest fires When the fire occurred, the moisture content of the object was determined to determine the main factors that affect the occurrence and development of forest fires and their proportion. Second, the method of measuring the four main factors that affect the occurrence of forest fire