内蒙古森林气象火险等级数值模拟个例研究

A case study on numerical simulation of forest weather fire risk grade in Inner Mongolia

按照中尺度模式与统计方法相结合的思路,对缺少观测资料的森林地区进行气象火险等级模拟,可以达到森林火险预警的目的。采用这一方法可以大大提高森林气象火险服务的能力,提供具有高时空分辨率的森林火险预警信息。以1997年5月2日内蒙古绰尔发生的特大森林火灾为例,利用一个三维M-γ尺度大气-土壤耦合模式,对该地火灾发生前、中、后期的气象要素场进行了模拟,并根据森林气象火险等级综合指数,最后得到了研究区域的气象火险等级时空分布状况。结果表明,该中尺度模式模拟能力强,气象要素场的模拟结果基本符合山区气候变化规律,分析的森林气象火险等级分布与实际情况符合得较好。由此可见,采用中尺度模式进行火险预警的方法,可以为森林防火提供较为可靠的指导。

Based on the method of combining meso-scale model with a statistical way, simulation of the weather fire warning grade for forest area where lacks observation data were performed. Service capability of weather fire warning of forest are increased greatly through this method compared to traditional method. It shows that the fire warning information with higher spatiotemporal resolution for forest area could be provided. Taking a serious fire occurred near the Aunier forestry center of Chuoer in Inner Mongolia on May 2,1997 for example, a simulation of meteorological element fields for the pre-period, the mid-period and the post-period of the forest fire were performed by means of a three dimensional M-γ scale air-soil coupling model. The spatiotemporal distributions of weather fire warning grade were obtained according to the weather fire grade comprehensive index. The result further shows that the model has a strong simulating capability and the analyzed weather fire grades coincide with the facts. From these, a conclusion can be drawn that the method using meso-scale climate model to forest-fire forecast may provide reliable information for forest-fire monitoring and prevention.