Forest fire risk depends on the hazard factors, affected body, and hazard prevention and reduction ability. The integrated risk assessment is the foundation for developing scientific fire mana-gement policies and carrying out the forest fire prevention measures. A forest fire risk assessment model and index system were established based on the classic natural disaster risk model and available data, and the model was used to assess the forest fire risks in past and future. The future climate scenario data included outputs from five global climate models (GFDL-ESM2M, HadGEM2-ES, IPSL-CM5A-LR, MIROC-ESM-CHEM and NorESM1-M) for RCP 2.6, RCP 4.5, RCP 6.0 and RCP 8.5, respectively. Each component index of Fire Weather Index (FWI) system was calculated daily for each grid in 1987-2050 for the historical observations and future climate scenarios according to the maximum temperature, minimum relative humidity, wind speed and daily precipitation. The results showed that areas with high and very high fire danger ratings in 1987-2010 accounted for 21.2% and 6.2%, respectively, which were distributed in Greater Xing'an Mountains and the Changbai Mountain area, most parts of Yunnan, and many fragment areas in southern China. The areas with high and very high burn possibilities were mainly distributed in the northeast and southwest region, accounting for 13.1% and 4.0%, respectively. Compared with the observation period, the areas with high and very high fire danger ratings in 2021-2050 would increase by 0.6%, 5.5%, 2.3%, and 3.5% under RCP 2.6, RCP 4.5, RCP 6.0, and RCP 8.5 respectively, and North China would show significant increase. The regions with high-risk forest fires would also increase due to climate change, with the most significant increase under RCP 8.5 scenario (+1.6%).
森林火灾风险主要取决于致灾因子、承灾体以及防灾减灾能力,综合评估和预测森林火灾风险是制定科学的林火管理政策的基础.本文基于经典自然灾害风险模型和可获取数据构建森林火灾风险评估模型与指标体系,评估过去和未来的森林火灾风险.未来气候情景数据包括RCP 2.6、RCP 4.5、RCP 6.0和RCP 8.5下5个全球气候模式(GFDL-ESM2M、HadGEM2-ES、IPSL-CM5A-LR、 MIROC-ESM-CHEM和NorESM1-M)日值数据.根据最高温度、最小相对湿度、平均风速和每日降水量分别计算1987—2050年历史观测数据和未来气候情景下各格点每日火险天气指数系统中各个指数.结果表明: 1987—2010年,森林火灾风险高和很高的区域分别占21.2%和6.2%,主要分布在大兴安岭和长白山地区、云南大部分区域和南方零散分布的区域.森林火灾可能性高和很高的区域主要分布在东北和西南地区,分别占森林面积的13.1%和4.0%.与观测时段相比,2021—2050年RCP 2.6、RCP 4.5、RCP 6.0和RCP 8.5情景下森林火灾可能性高和很高的区域分别增加0.6%、5.5%、2.3%和3.5%,华北地区增幅明显.气候变化引起的森林火灾高风险区域有些增加,RCP 8.5情景下增幅最明显(+1.6%).
Keywords: climate change; forest fire; possibility; risk assessment; vulnerability.