多源时序国产卫星影像的森林火灾动态监测

四川省木里县及周边林区是全国林火最为高发和易发区之一，近两年连续发生了扑火人员重大伤亡的事件。利用时序国产卫星影像、无人机影像和现场勘查数据等，从监测火灾蔓延时空过程的角度，对该区林火热点进行了动态监测，并分析了重点火场火灾发展过程，结果表明：以国产GF-4卫星影像为主，辅助以2 m/8 m光学卫星星座影像，可较好地监测林火热点；研究提出林火热点判定阈值为白天亮温值T≥360 K或夜间亮温值T≥330 K；监测发现了该区3月30日至4月6日间共6处火场的25次林火事件，并重点反演了①号木里和②号西昌火灾发展的时空过程。通过将卫星监测热点与现场勘查热点、无人机影像解译热点对比，表明在火灾早期和中期卫星林火热点监测精度可达89%。建议利用时序国产多源卫星影像对该区林火进行持续监测，并结合权威部门现场勘查数据适时发布预警信息，避免造成重大生命财产损失。

Forest Fire Dynamic Monitoring based on Time Series and Multi-source Satellite Images: A Case Study of the Muli County Forest Areas in Sichuan Province

Muli County and its surrounding areas in Sichuan Province are one of the most frequent and vulnerable forest fire areas in the China. In the past two years， there have been serious casualties of firefighters in forest fire fighting. In this paper， time-series and multi-source satellites images， UAV images and disaster site survey data are used to monitor the forest fire hot spot dynamically， and the process of fire spread in Muli County were analyzed. The results show that： The GF-4 Satellite images and 2 m/8 m optical satellite constellation images， which can be used for forest fire hotspots monitoring effetely. We believe that the grid can be determined as the forest fire hotspot， while the grid temperature value T≥360 K in the daytime or temperature value T≥330 K in the nighttime. 25 forest fire incidents in 6 fire sites were found and monitor from March 30 to April 6 in the area， and the progress of the fire in Muli and Xichang County were also investigated with the hot spot. Compared with the high-resolution unmanned aerial vehicle images and the collecting hot spot data of fire site， it shows that the accuracy of satellite forest fire hotspot monitoring can reach 89%. It is recommended to use time-series and multi-source satellite images to monitor the forest fires in this area continuously， and combine the fire site survey data of authoritative departments for timely fire warning. It is also suggesting that combine meteorological， topographic， vegetation and human factors to carry out fire cause analysis and risk assessment studies， to avoid causing loss of life and property again.