Burn severity and fire spread in the Purépecha region of Michoacán, Mexico, in 2024 using remote sensing

Abstract

Introduction. Fire severity refers to the magnitude of ecological change caused by fire and is influenced by fire intensity and duration, as well as by vegetation density and type. Fire severity can be assessed using satellite-derived data. Objective. To analyze the major wildfires detected by the NOAA-21 VIIRS sensor in the Purépecha region of Michoacán in 2024 to determine the burned area, affected land-cover types, severity, and fire spread. Materials and methods. Using Sentinel-2 imagery of the study area, pre- and post-fire differences in the Normalized Burn Ratio (dNBR) and Normalized Difference Vegetation Index (dNDVI) were calculated and analyzed by land-cover type. Results. A total of 18 815.43 ha were burned. Agricultural burning accounted for 19 % of the burned area, while pine forest accounted for 33 %; the latter had the largest area classified as highly affected, totaling 1 088.15 ha. The analysis identified 12 burned areas, most of them located in the municipality of Chilchota. Some fires originated from agriculture burning, whereas most fires in forested areas were attributed to negligence or to the expansion of avocado production. Conclusions. The burned areas showed varying levels of fire severity, which may facilitate post-fire recovery if seed banks remain in the less severely affected patches. In pine forests, areas experiencing low to moderate fire severity showed relatively small reductions in vegetation density, suggesting that relatively rapid recovery may be expected.