卫星遥感数据在林火排放模型中的应用

火对大气中的温室气体和气溶胶的增加有显著影响,也是植被的一个主要干扰因子.利用精确卫星火产品对中国林火排放量进行量化计算,对于制定正确的减排战略具有参考意义.采用GBA2000的研究结果,分析了不同植被区的过火区分布情况.2000年中国林地上共有8 587个过火斑块,总面积为10 773 212 hm2,其中阔叶落叶林过火面积最大,为3 674 404 hm2;其次为阔叶常绿林,过火面积为1 141 402 hm2.林火排放计算模型采用各植被带平均生物量和燃烧系数估计火烧消耗的生物量和计算森林燃烧释放的温室气体量.我国2000年林火释放CO2 688 Tg,CO和CH4分别为57 Tg和4 Tg.计算精度取决于森林火灾面积、土地类型图、燃烧效率和排放因子.由于采用的卫星火产品没有对中国区域进行精度评估,据此统计的森林过火区有误差.如果采用更精确的卫星遥感数据,将提高林火释放模型的计算精度.

An emission model for the use of satellite data to the forest fire evaluation

This paper is aimed at introducing the authors' Emission Model for the use of satellite data to the forest fire estimation based on the results of our study of the Global Burnt Area project in 2000.As is known,forest balefire yields an important contribution to the green gases and aerosol in the troposphere,which is also a dominant disturbing factor in most ecosystems.Needless to say,it is of the same significance in China as in other countries of the world to use satellite fire products to analyze and calculate the fire emissions,particularly,to establish a suitable emission mitigation strategy.For this purpose,the paper analyzed the burnt areas in different vegetation zones in the world in 2000 based on the results of the Global Burnt Area project.According to the state statistics,8,587 fire scars took place in that year with the burnt area being 10 773 212 hm~2 all over the country.The biggest hit took place with the deciduous broadleaf forest with the burnt area of 3 674 404 hm~2.Next is with the evergreen broadleaf forest,which covered an area of 1 141 402 hm~2.The average biomass and combustion factor values are used in fire emission model to calculate the available fuel and fire emissions.With the fire emission model we have calculated the forest fire emissions in 2000 of CO_2 688 Tg,CO 57 Tg and CH_4 4 Tg.Since there was lack of sufficient valid assessment in China for the satellite data,there might exist some errors in estimating the burnt areas.However,the paper has just focused on the method of using the satellite fire products on the fire emission model,which is likely to be used as the main sources for the future balefire emission practice.