基于长时序影像的大兴安岭山脉林火扰动识别与时空分布格局OA

[Objective]This study aims to investigate the spatiotemporal distribution patterns of wildfire disturbances and identify trends in forest fire dynamics,providing a scientific basis for preventing fires in high-risk areas and optimizing the allocation of fire prevention resources.[Method]We applied the LandTrendr temporal segmentation algorithm to extract forest change characteristics,combined with a random forest model for identifying forest fire disturbance areas.On this basis,spatial statistical methods are utilized to analyze the interannual variation trends and spatial distribution patterns of forest fire disturbances.Furthermore,topographic factors are integrated to investigate the distribution patterns of different fire severities and secondary fires.[Result](1)From 1987 to 2022,the total wildfire disturbance area in the Greater Khingan Mountains exhibited a significant overall decline,without distinct stage characteristics.(2)Wildfire disturbances displayed a clustered pattern at spatial scales of 0-180 km.The high-density core region was located at the intersection of Oroqen Autonomous Banner,Genhe City,and Huma County in the central-eastern area,while low-density zones were found in the western and southern regions.The disturbance extent initially expanded outward,then gradually contracted,with the fire center shifting southward before partially returning northward.(3)Wildfire disturbances were concentrated on gentle and sloping terrains,with high-severity fires more likely to occur on sunlit(south-facing)slopes.Elevations between 400 and 800 m represented a fire-prone belt,and low-elevation areas showed significantly higher recurrence rates of secondary fires.Although steep slopes accounted for a small area,they exhibited a high proportion of severe fires.[Conclusion]Wildfire patterns in the Greater Khingan Mountains are characterized by eastern clustering,western dispersion,and central concentration,and fire occurrence is dominated by gentle and south-facing slopes,with risk concentration at mid-elevations.We recommend prioritizing the deployment of fire prevention infrastructure in high-risk areas,particularly in Oroqen Autonomous Banner,Genhe City,and Huma County at the border of Inner Mongolia Autonomous Region and Heilongjiang Province,and enhancing fuel management strategies on sunlit slopes to improve the precision of wildfire prevention and control.