Fire-Environment Analysis: An Example of Army Garrison Camp Williams, Utah

Scott M Frost,R Justin Derose,Michael J Jenkins,Martin E Alexander

doi:10.3390/fire3010006

Abstract

The planning of fuel treatments for ecological or societal purposes requires an in-depth understanding of the conditions associated with the occurrence of free-burning fire behavior for the area of concern. Detailed fire-environment analysis for Army Garrison Camp Williams (AGCW) in north-central Utah was completed as a prerequisite for fuel treatment planning, using a procedure that could be generally applied. Vegetation and fuels data, topographic and terrain features, and weather and climate data, were assessed and integrated into predictive fuel models to aid planning. A fire behavior fuel model map was developed from biophysical variables, vegetation type, and plot survey data using random forests, and resulted in an overall classification rate of 72%. The predominate vegetation type-fuel complex was grass, followed by lesser amounts of Gambel oak, Wyoming big sagebrush and Utah juniper. The majority of AGCW is mountainous in nature, characterized by slopes less than 40% in steepness with slightly more northerly and easterly aspects than south and west, and elevations that ranged from 1650 to 1950 m above mean sea level. Local fire weather data compiled from the three nearest remote automated weather stations indicated that average temperature maxima (32 °C) and relative humidity minima (12%) usually occurred between 1400 to 1500 h daily, and from July to August, seasonally. The semi-arid climate at AGCW, coupled with the corresponding preponderance of flashy fuel types and sloping terrain, constitutes a formidable fire environment in which to plan for mitigating against adverse fire behavior.

Highlights

Large fires (400 ha +) occur about every seven to ten years in the vegetation types located at the U.S Army Garrison Camp Williams (AGCW) practice range, located in north-central Utah (Figure S1)
We identify the characteristics of potential fire behavior, and, in turn, fire impacts and effects, that can be estimated as functions of fuel, terrain, and weather [25]
Fifteen percent of total vegetation was classified as Gambel oak

Summary

Introduction

Large fires (400 ha +) occur about every seven to ten years in the vegetation types located at the U.S Army Garrison Camp Williams (AGCW) practice range, located in north-central Utah (Figure S1). In 2010 and 2012, for example, wildfires burned beyond the boundaries of AGCW into the adjacent wildland-urban-interface (WUI). In the context of WUI fire protection, the configuration of topography and local weather patterns in AGCW is extremely problematic. Prevailing winds and the steepest slopes tend to align along the northern ridge of the AGCW, immediately south of the burgeoning WUI. This same area is dominated by shrubby Gambel oak (Quercus gambellii Nutt.) on southern exposures—which was precisely the location where a fuelbreak was breached in 2010 by the Machine Gun Fire that subsequently burned multiple structures in the community of Herriman, Utah

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