The impact of UAS aerial ignition on prescribed fire: a case study in multiple ecoregions of Texas and Louisiana

Abstract

BackgroundSmall Unmanned Aerial System (UAS) technologies and their applications have expanded in recent years, to include aerial ignition support in prescribed fire and wildland fire settings. In 2019, we incorporated the use of UAS aerial ignition into our existing prescribed fire program of over 20 years. To assess its impact, comparisons of UAS and non-UAS burns were performed on burn data from 2012 to 2021, with 58 total UAS burns conducted from 2019 to 2021. A subset of these burns conducted at Cook’s Branch Conservancy in Montgomery County, TX, included post-burn assessment data, which we used to compare UAS and non-UAS fire effects.ResultsNon-parametric significance tests were used to analyze and compare non-UAS burning before (2012–2018) and after (2019–2021) the incorporation of the UAS, and UAS burning from 2019 to 2021. Response variables included ha day−1 burned and six different post-burn assessment metrics. Principal findings were that from 2019 to 2021, UAS burns were 61 ha day−1 or 129% more efficient than non-UAS burning and required one extra staff member to pilot the UAS on average. This increase enabled a previously unachievable efficiency in terms of hectares burned each year vs days burned each year when using the UAS. While fire effects were less severe for most post-burn assessment metrics during UAS burning, burn results still met fuel management goals when compared to non-UAS burning.ConclusionsA large increase in ha day−1 was previously unachievable, making the UAS a viable tool for accomplishing safer and more effective prescribed burn operations in the limited number of suitable days available. When managed responsibly, UAS aerial ignition is poised to have a positive impact on the safe and effective application of prescribed fire, resulting in more achievable conservation and fuel management goals.