Spatial and temporal variability of forest fires in the Republic of Korea over 1991-2020

Forest fires have increased over the last several decades in many regions. Quantifying the general patterns of frequency, areal extent, and seasonality is crucial for understanding fire dynamics. This study aimed to investigate whether the spatial and temporal trends in forest fires have changed across South Korea. The Mann-Kendall test and Sen's slope estimation were used to analyze the temporal trends in forest fire statistics from 1991 to 2020. The spatial dispersion of fire activity was detected using a standard deviation ellipse and hotspot analysis. An average of 451 fires have occurred annually over the last 30 years, with a yearly increase of 5.82 fires. The burned area in April and May accounted for 80.7% of the annual burned area. The length of the fire season in 2006-2020 was 25 days longer than that in 1991-2005. The risk of large fires is increasing and becoming more concentrated in the northeastern region, such as the Gwangwon and Gyeongsangbuk Provinces of South Korea. Both climate change and forest recovery have led to South Korea becoming more prone to fires. However, forest fires are not burning more intensely nor charring more areas than they did previously. This is probably due to the implementation of surveillance and initial attack systems. Targeted forest fire suppression policies can help to effectively reduce the risk of forest fires in South Korea.