A Geospatial Framework to Assess Fireline Effectiveness for Large Wildfires in the Western USA

Benjamin M Gannon,Matthew P Thompson,Kira Z Deming,Yu Wei,Jude Bayham,Christopher D O’Connor

doi:10.3390/fire3030043

Abstract

Quantifying fireline effectiveness (FLE) is essential to evaluate the efficiency of large wildfire management strategies to foster institutional learning and improvement in fire management organizations. FLE performance metrics for incident-level evaluation have been developed and applied to a small set of wildfires, but there is a need to understand how widely they vary across incidents to progress towards targets or standards for performance evaluation. Recent efforts to archive spatially explicit fireline records from large wildfires facilitate the application of these metrics to a broad sample of wildfires in different environments. We evaluated fireline outcomes (burned over, held, not engaged) and analyzed incident-scale FLE for 33 large wildfires in the western USA from the 2017 and 2018 fire seasons. FLE performance metrics varied widely across wildfires and often aligned with factors that influence suppression strategy. We propose a performance evaluation framework based on both the held to engaged fireline ratio and the total fireline to perimeter ratio. These two metrics capture whether fireline was placed in locations with high probability of engaging with the wildfire and holding and the relative level of investment in containment compared to wildfire growth. We also identify future research directions to improve understanding of decision quality in a risk-based framework.

Highlights

Progress is being made in the USA towards risk informed, safe, and efficient fire management, but limited suppression effectiveness data collection and analysis inhibits efforts to evaluate the quality of wildfire management decisions and the subsequent adaptive management of suppression practices [1,2,3,4,5]
As a coarse proxy for protection concerns, we divided the fires into frontcountry and backcountry groups based on having less than or greater than 50% area burned in USDA Forest
We present a summary of each performance metric using example fires at the low and high ends of the distribution to provide context for how each metric relates to incident characteristics

Summary

Introduction

Progress is being made in the USA towards risk informed, safe, and efficient fire management, but limited suppression effectiveness data collection and analysis inhibits efforts to evaluate the quality of wildfire management decisions and the subsequent adaptive management of suppression practices [1,2,3,4,5]. Many fine-scale fire processes and management interventions are best studied with controlled experiments, containment strategy evaluation necessarily relies on observational data from actual incidents. Fire 2020, 3, 43 suppression resource actions, fire behavior, and values threatened in space and time—that are lacking in quantity and quality within many fire organizations [6,7,8,9] Despite these challenges, the increasing availability of spatially explicit fireline records provides the means to evaluate certain aspects of containment strategy performance using fireline effectiveness (FLE) metrics based on quantified measures of the length of final wildfire perimeter and how much fireline burned over, held, or did not engage with the wildfire [9,10]. FLE performance metrics are attractive because of their modest data and analysis requirements, but there is a need to expand their application beyond a small set of case studies to understand how they can be utilized to evaluate the effectiveness of incident-level strategies

Methods

Results

Conclusion