基于MODIS数据的森林火险时空分异规律研究

Forest Fire Division by Using MODIS Data Based on the Temporal-Spatial Variation Law

森林火灾严重危害生态环境,引起了全球的高度重视。将从MODIS(MODerate-resolution imagingspectroradiometer)中提取的活动火点与历史火烧痕迹进行比较研究,发现MOD14A1(火掩膜数据产品a dai-ly Level 3 1-km fire hot spot product)中提取的8+9波段适合消防监测,与现场勘察数据相比较吻合度高达0.83。使用MOD14A1中8+9波段结合相关数据对这个区域的长达11年(2000—2010年)的森林火灾发生的时间和空间分析,结果表明:火灾发生频率最多的是春季,秋季次之,夏天概率最低,除非干旱。通过对研究区域黑龙江省分析,针叶林和温带针阔混交林过火面积所占比例分别为53.68%,44%,草原区过火面积较小为2.32%。大兴安岭是主要的燃烧区域,面积达到64.74%,小兴安岭约为23.49%,而其他区域面积不超过5%。且火灾发生的较大部分森林有个平缓的斜坡(≤5°),大部分处于中海拔(200m≤H≤500m)。因此,通过卫星遥感对森林火区区域的时间序列分析,阐明火灾活动规律和气候、地形、植被类型的相互关系,有助于预测火灾区域危险性等级。

Forest fires are harmful to the ecological environment,which have induced global attention.In the present paper fire activities extracted from MODIS and burned areas were compared,and it was found that the wave band of 8～9extracted from MOD14A1was useful for fire monitoring,and the data accorded with field investigation with goodness of fit reaching up to 0.83.Through combining this wave band and the relative data to make the time and space analysis of the forest fires for 11 years,from 2000to 2010,the study showed that the fire occurred most frequently in the spring,the autumn took the second place,and in the summer there was almost no fire occurrence unless drought.Through the analysis of the research area,the burned areas of the coniferous forest and temperate mixed forest were 53.68%and 44%,respectively,while the grassland was only 2.32%.Da Hinggan Ling region was the main combustion area,the burned areas were 64.7%and that for Xiao Hinggan Ling was about 23.49%,while those for other areas were less than 5%.The majority of forest land of burned areas has a gentle slope（≤5°）,and is in the middle altitude between 200and 500m.So,using satellite remote sensing to analyze the time series of burned areas in forests would make the relationship between the fire activities,climate change,topography and vegetation type clear and it is also helpful to predicting the risk level of the fire areas.