中文摘要：

根据西藏林芝地区的DEM数据和植被分布数据分析了该地区可燃物的水平分布和垂直分布规律，并根据火发生纪录分别计算了火发生周期和发生概率，根据火灾高发期的降水和气温数据分析降水和气温的变化趋势，本地区易发生火灾的可燃物主要有高山松云南松林，草甸灌丛，云冷杉林等。该地区的火灾轮回期为17178a，火发生概率为0．00006，远远低于东北林区，但由于该地区处于高海拔地区，生态系统脆弱，林木蓄积量大，积累能量高，潜在的火强度高。林芝地区夏季降水减少，火灾高发期（2～5月）降水有所增加，但增温明显，气温升高对高海拔地区的影响比低海拔地区更大，时于森林可燃物而言，气温增高使高海拔地区的森林火险增大，森林防火面临的形势更加严峻。

英文摘要：

The distribution of forest fuel is very important to the occurrence of forest fires. This paper used DEM data and vegetation distribution map to analysis the horizontal and vertical distribution of forest fuel, and calculated the fire circle and fire probability based on the fire history data as well. The tendency of fire occurrence was analyzed from the precipitation and air temperature records. This region locates in high altitude area, the ecosystem is fragile, the forest volume is large, and the potential fire intensity is very high. The growing tendency of temperature in recent years impel fire danger rating to rise quickly, the impact of temperature rising is more severe on high altitude area than on low altitude area, and the fire danger rating situation of high altitude area is more severe.