Temporal and spatial pattern analysis of escaped prescribed fires in California from 1991 to 2020

Prescribed fires play a critical role in reducing the intensity and
severity of future wildfires by systematically and widely consuming
accumulated vegetation fuel. While the current probability of prescribed
fire escape in the United States stands very low, its consequential
impact, particularly the large wildfires it causes, raises substantial
concerns. The most direct way of understanding this trade-off between
wildfire risk reduction and prescribed fire escapes is to explore patterns
in the historical prescribed fire records. This study investigates the
spatiotemporal patterns of escaped prescribed fires in California from
1991 to 2020, offering insights for resource managers in developing
effective forest management and fuel treatment strategies. The results
reveal that the months close to the beginning and end of the wildfire
season, namely May, June, September, and November, have the highest
frequency of escaped fires. Under similar environmental conditions, areas
with more records of prescribed fire implementation tend to experience
fewer escapes. The findings revealed the vegetation types most susceptible
to escaped prescribed fires. Areas with tree cover ranging from 20 to 60%
exhibited the highest incidence of escapes compared to shrubs and
grasslands. Among all the environmental conditions analyzed, wind speed
stands out as the predominant factor that affects the risk of prescribed
fire escaping. These findings mark an initial step in identifying
high-risk areas and periods for prescribed fire escapes. Understanding
these patterns and the challenges of quantifying escape rates can inform
more effective landscape management practices.