基于MODIS数据的亚马逊热带雨林火灾时空变化规律研究

频繁发生的森林大火对亚马逊热带雨林造成了大面积破坏，获取不同年份的火灾影响范围以及植被破坏情况，有助于了解该地区火灾时空演变规律以及火灾与植被的相互作用关系，进而探究火灾发展机理，为防灾减灾提供科学依据。为此，利用2015~2019年MODIS植被指数产品与地表温度产品，构建MODIS全球扰动指数模型（MGDI），结合火点数据 （以下统称MOD14A1）、植被连续场数据（Vegetation Continuous Field，VCF）提取1 000 m分辨率下的燃烧范围和燃烧强度，并分析研究区域5年内的火灾分布时空规律。实验结果表明：①火灾主要分布在巴西中部以及巴西与玻利维亚的交界处，占燃烧区总面积的67%左右；②燃烧范围以及燃烧强度的综合信息显示火灾整体呈现出“升—降—升”的趋势；③火灾多发生于灌木草地（50%以上）以及阔叶林（30%），且火灾多发在旱季；在全球变暖大背景下，火灾发生频率呈上升趋势；（4）人类活动范围扩张、不合理农业开垦、森林砍伐导致研究区内草地退化严重，农业用地以及建筑用地逐年上升，在一定程度上为火灾的发生、传导提供了良好的条件。

Spatial-temporal Variability of Amazon Tropical Rainforest Fire based on MODIS Data

Frequent forest fires have caused extensive vegetation destruction in the Amazon tropical rain forest. It’s of great importance to obtain the fire influence range and vegetation destruction in different years to understand the spatio-temporal evolution of fire in this area， study the interaction between fire and vegetation， and then explore the fire development mechanism， so as to provide a scientific basis for disaster forest and reduction. To this end， the MODIS vegetation index products and surface temperature products range from 2015 to 2019 were used in this paper to construct the MODIS Global Disturbance Model （MGDI）， combined with fire point data （hereinafter collectively referred to as MOD14A1） and Vegetation Continuous Field （VCF）to extract combustion scope and intensity at 1 000 m resolution， and the spatial and temporal law of burned area within 5 years of the study area was analyzed. The results revealed that ：（1） Burned area are mainly distributed in the central part of Brazil and the border between Brazil and Bolivia， accounting for about 67% of the total burning area；（2） The information of burned area and burned intensity comprehensively `indicated that the fire showing a “rise-drop-rise” trend；（3） The fire mainly occurred in shrub grassland（more than 50%） and broad-leaved forest（30%）， and most of them took place during the dry season； under the global warming circumstance， the fire frequency increased a lot；（4） The expansion of human activities， unreasonable agricultural reclamation and deforestation lead to serious grassland degradation in the study area， and agricultural land and construction land are increasing year by year， which provides good conditions for the occurrence and conduction of fire to a certain extent.