西南林区森林火灾火行为模拟模型评价

林火火行为特征是进行及时有效的林火预防和扑救的重要技术参考,国外普遍做法是借助火行为模拟模型进行获取.本文选用美国和加拿大行业普遍使用的Farsite和Prometheus火行为模拟模型对发生在中国西南林区的安宁“3·29”森林大火进行模拟,通过对比模拟结果和相关林火资料,定量评价模型的模拟精度.结果表明: 在蔓延范围模拟方面,Farsite在Scott可燃物模型下的模拟精度最高,Prometheus最差,但差距不大,Farsite与Prometheus火场范围的差异区主要集中在云南松分布区;在蔓延速度(ROS)模拟方面,Farsite在2种可燃物模型下的平均ROS模拟输出最接近实际情况,Prometheus则偏离实际情况较远,Farsite与Prometheus的ROS差异区主要集中在云南松分布区;在火线强度(FLI)模拟方面,Farsite在2种可燃物模型下的平均FLI模拟输出结果类似,Farsite与Prometheus的输出差异较大,差异区主要集中在栎类灌木分布区.

Evaluating fire behavior simulators in southwestern China forest area.

As an important technical reference for efficient prevention and fighting against forest fire, forest fire behavior parameters are mainly obtained from fire behavior simulators in some deve-loped countries. This study selected two simulators, the Farsite from USA and the Prometheus from Canada, which were both widely used in local area. Through comparing simulated results and relative data of the ‘3·29 Fire’ occurred in Anning City, Southwestern China, we tried to evaluate accuracy of the simulators in a quantitative way. The results indicated that, in the simulation of peri-meter, the precision of Farsite under Scott fuel model was the highest, while Prometheus was the lowest, but the difference was not significant. The difference in simulative perimeter between Farsite and Prometheus mainly concentrated in the distribution area of Pinus yunnanensis. In the simulation of rate of spread (ROS), the mean ROS results of Farsite under both fuel models were close to the actual situation, while the results of Prometheus were far away from the actual situation. The diffe-rent simulative area of ROS between Farsite and Prometheus mainly concentrated in the distribution area of P. yunnanensis. In the simulation of fireline intensity (FLI), the mean FLI results of Farsite under both fuel models were similar, and Prometheus obtained significantly different FLI results from Farsite, while the different simulative area of FLI between Farsite and Prometheus mainly concentrated in the distribution area of Quercus.