The Cooney Ridge Fire Experiment: An Early Operation to Relate Pre-, Active, and Post-Fire Field and Remotely Sensed Measurements

Andrew Hudak,Robert Tissell,Bret Butler,James Riddering,Patrick Freeborn,Sarah Lewis,Lee Macholz,Robert Kremens,Leigh Lentile,Lloyd Queen,Bryce Nordgren,Edward Mathews,Penelope Morgan,Casey Teske,Colin Hardy,Sharon Hood,Benjamin Bright,Helen Smith,Philip Riggan

doi:10.3390/fire1010010

Abstract

The Cooney Ridge Fire Experiment conducted by fire scientists in 2003 was a burnout operation supported by a fire suppression crew on the active Cooney Ridge wildfire incident. The fire experiment included measurements of pre-fire fuels, active fire behavior, and immediate post-fire effects. Heat flux measurements collected at multiple scales with multiple ground and remote sensors illustrate the spatial and temporal complexity of the fire progression in relation to fuels and fire effects. We demonstrate how calculating cumulative heat release can provide a physically based estimate of fuel consumption that is indicative of fire effects. A map of cumulative heat release complements estimates of ground cover constituents derived from post-fire hyperspectral imagery for mapping immediate post-fire ground cover measures of litter and mineral soil. We also present one-year and 10-year post-fire measurements of overstory, understory, and surface conditions in a longer-term assessment of site recovery. At the time, the Cooney Ridge Fire Experiment exposed several limitations of current state-of-science fire measurement methods, many of which persist in wildfire and prescribed fire studies to this day. This Case Report documents an important milestone in relating multiple spatiotemporal measurements of pre-fire, active fire, and post-fire phenomena both on the ground and remotely.

Highlights

Fire behavior is related to first-order fire effects such as fuel consumption, stem and soil heating, crown scorch, and smoke production [1,2,3]
The experimental burnout operation on 3 September 2003 began at approximately 13:00 Mountain Daylight Time (MDT), but the fire did not enter the fuel plot until approximately 15:45
From a practical standpoint these atmospheric windows permit much of the fire emitted radiance to reach the sensor unattenuated, the challenges of estimating the spectrally integrated radiant heat flux from a spectral brightness temperature measurement has inspired the development of several novel approaches, namely, the emissivity-area product [44,48], a semi-empirical approach based on simulated sub-pixel thermal distributions [27], and the middle infrared (MIR) radiance method [25]

Summary

Introduction

Fire behavior (e.g., reaction intensity, spread rate, flame height, and residence time) is related to first-order fire effects such as fuel consumption, stem and soil heating, crown scorch, and smoke production [1,2,3]. When used to develop cause–effect relationships with respect to first- and second-order fire effects, these inferences frequently become circular. The technology required to characterize the fire environment in such a way as to provide robust thermodynamic data has only recently been developed, and the deployment of these technologies has been largely limited to exploratory research. Such technology that does exist for in situ measurements of the fire environment can only provide point or, at best, spatially disconnected observations. Radiometric measurements of heat transfer currently provide the best means to link fire behavior to fire effects using currently available technologies [8]

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Results

Discussion

Conclusion