我国北方森林草原地区火险等级遥感评估及时空特征分析

Fire Danger Rating Assessment and Spatial-temporal Characteristic Analysis of Forest and Grassland in North China Using Remote Sensing

我国是森林草原资源大国,但频发的森林草原火灾给我国生态环境建设和经济发展带来极大的损失。火险等级评估作为一项科学防火的重要方法手段,可以为森林草原防火提供科学有效的决策支持信息。相对气象台站获取的数据,遥感数据在大区域尺度地表信息反演上不受空间复杂性和插值的影响。因此,利用遥感进行森林草原火险等级评估,具有重大的理论意义和应用价值。本文以我国北方4省为主要研究区,根据其森林草原生态环境特点,结合资源环境领域遥感研究的已有成果,选取了5个基于遥感数据反演的火险评估指标,利用层次分析法构建了火险指数模型,确定火险分级原则,进行火险等级评估研究。依据火险等级评估的时间序列结果,分析了我国北方地区森林草原火险季节变化与区域分布特征。

The resource of forest and grassland is abundant in China with a vast territory.Furthermore,forest and grassland are important to socio-economic development and environmental protection in China.But frequent fire occurring in forest and grassland caused a lot of economic and environmental damages.The study on fire danger rating is a meaningful way in forest and grassland fire management and can provide useful information to support the fire management decisions.Based on the characteristic of remote sensing data,five fire danger indicators were selected：Degree of vegetation curing,Fuel weight,Land surface temperature,Vegetation continuity degree and Equivalent water thickness.The method of Analytical Hierarchy Process（AHP） was used to integrate the five indicators and calculate the Remote Sensing Fire Danger Index（RSFDI）.RSFDI was validated by analyzing the statistic relation between RSFDI and meteorological data from observation station.Using the constituted criterion referring to Forestry Industrial Standard,fire danger rating distribution can be mapped and analyzed at the temporal and spatial scale.The analyzing result showed that the temporal change and spatial distribution of fire danger rating in consistency with the fire and hazard occurrence in the study area.