北京地区近两年春季森林火险对比研究

火险等级预报系统已经成为现代林火管理的一个重要工具。本文根据北京地区的森林火险天气，采用加拿大火天气指数系统（FWI）评估北京地区的森林火险。根据北京地区12个气象站2004年和2005年3-5月的气温、相对湿度、降水、风速，利用SAS计算程序，计算各气象站每日的FWI各组分值。分析FWI系统各组分的数值分布特征，确定了北京地区FWI各指数的等级划分及其指示意义。利用内插方法建立可燃物湿度码与火天气指数的空间分布图，分析2004年和2005年春季实际发生的森林火灾与相关的火险指数，结果表明FWI系统能很好地反映森林火险的变化，可以用于评估和预测火险。火险期危险度表明2005年春季森林火险高于2004年春季。文章最后讨论了不同内插方法对研究结果的影响。

Study on Assessment of Beijing Forest Fire Danger

Fire danger rating system has already been a significant tool for modem forest fire management. This paper uses Canadian fire weather index system to assess the forest fire danger of Beijing based on the local fire weather. Using air temperature, relative humidity precipitation and wind speed on noon, we calculate the daily component indexes of FWI with a SAS program. The definition of FWI components is given for Beijing forest fire danger rating on the basic of analysis of the indexes distribution. We make maps of fuel humidity codes and fire weather index by using interpolation method. The relationship between forest fire and relative fire danger indexes in 2004 and 2005 spring indicates that the FWI system can reflect the fire danger rating and can be used to assess and forecast the forest fire danger rating. The season severity rating shows that the fire danger in 2005 is higher than that in 2004. Finally, the influence of different interpolation on the results is discussed.