Glossary of wildfire hazard and risk (2019)
This glossary of wildfire hazard and risk terminology is maintained by Pyrologix. Initial development of an earlier version was assisted by Matthew P. Thompson at the Rocky Mountain Research Station.

Understanding stochastic wildfire simulation results (2014)
This document provides awareness-level information about stochastic wildfire simulation systems by describing their inputs and outputs, along with a simplified description of how they work. This report was prepared by Joe Scott of Pyrologix for the USDA Forest Service Washington Office.

Summarizing contemporary large-fire occurrence for land and resource management planning (2014)
When it comes to wildfire management planning, the recent past may be a guide to the near future. This whitepaper describes an analysis process for summarizing contemporary historical wildfire occurrence for a designated portion of the landscape. This document was prepared by Joe Scott of Pyrologix for the USDA Forest Service Washington Office.

Introduction to Fire Behavior Modeling (2012)
This report provides a foundation upon which to build fire behavior modeling experience gained during an apprenticeship under a master or journey-level fire behavior modeler.

Fuel model help file
This document is a compiled help file (.chm). Save it to your computer and then simply double-click on the NewFuelModels.chm file to open it. Modern versions of Windows may require an extra step to properly view the help file. If you are having trouble opening the file once it’s been downloaded, refer to this Microsoft Help page.

The help file describes characteristics of the new fuel model set, its development, and its relationship to the original set of 13 fire behavior fuel models. To assist with transition to using the new fuel models, a fuel model selection guide, fuel model crosswalk, and set of fuel model photos are provided. The content of the help file mirrors the related General Technical Report.

Original Spreadsheet for comparing fuel models 
This spreadsheet is the “original” spreadsheet produced so that you can make quick, simple comparisons of the new fuel models with each other and with the original 13 fuel models. Guidance for using the spreadsheet is included in the helpfile, described below.

Updated spreadsheet for comparing fuel models (2023.1) 
Although the original CompareModelsFour.xls spreadsheet continues to serve its purpose of simply comparing the fire behavior predicted for different fuel models, our public and private sector colleagues asked for a few additional features, which are now incorporated into this “S495” version. These added features include: the inclusion of fuel model numbers in addition to fuel model codes, the addition of a simple model of wind adjustment factor for each fuel model or for different canopy cover values, conversion of the X-axis to the 20-ft wind speed from the midflame height, and the inclusion of Rothermel’s crown fire rate of spread as a “fuel model” on the chart. An intrepid user will also be able to add custom fuel models to the list.

In 2022 an update to Microsoft Excel caused the drop-down lists to behave poorly. The _2023.1 version linked above works around that issue by moving the graph to a regular worksheet rather than a dedicated graph page.

Montana Wildfire Risk Assessment Webinar

Pyrologix completed a wildfire risk assessment for the State of Montana in April 2020. The final presentation was completed as a webinar for the Northern Rockies Fire Science Network. The first half-hour of the presentation is a general background on concepts, terminology, and methods for assessing wildfire risk. The next hour details the Montana Wildfire Risk Assessment, which serves as an interpreted example of the risk assessment framework.

Geospatial fire modeling for landscape-scale fire management planning
In the Spring of 2012, Joe Scott presented an hour-long seminar at the Missoula Fire Science Lab’s Seminar Series. The presentation covered state-of-the-art geospatial modeling techniques to support fire management planning, including comprehensive, integrated wildfire risk assessment.

TIARA—Tetons Interagency Wildfire Risk Assessment
In March of 2014, Joe gave a webinar as part of the Northern & Southern Rockies Fire Science Networks Series sponsored by LANDFIRE and the Nature Conservancy. In this presentation, Joe outlined the quantitative risk assessment framework described in this publication, using the results of the Tetons Interagency wildfire risk assessment to illustrate the concepts.

Does one percent of the land area account for 99% of the wildfire threat?
The Pareto Principle—also called the 80-20 rule—states that a small number of things often accounts for a large majority of effects. With wildfire, this principle has been demonstrated for the relationship between the number of fires and their sizes. In this presentation, which was offered at the December 2012 5^th International Fire Ecology and Management Congress in Portland, Oregon, Joe used results of a wildfire risk assessment on the Lewis and Clark National Forest in Montana to answer the title question—does the Pareto Principle apply spatially, to land area. The short answer: oh, yes, yes it does.

A comprehensive set of standard fire behavior fuel models for use with Rothermel’s spread model
In 2006, shortly after publication of the “new” set of fire behavior fuel models, Joe Scott prepared this self-study presentation for the frames.gov website. This presentation will be useful primarily for those who have had no introduction to the comprehensive set of 40 fuel models at all, or anyone needing a quick refresher on how they relate to other fuel model sets.

Nexus 2.1

NEXUS 2.1 is crown fire hazard assessment software that links separate models of surface and crown fire behavior to calculate indices of relative crown fire potential. Use NEXUS to compare crown fire potential for different forest stands, and to compare the effects of alternative fuel treatments on crown fire potential. NEXUS includes several visual tools useful in understanding how the operational surface and crown fire models used in the United States interact.

Crown fire hazard assessment and behavior prediction is an emerging science. In NEXUS we have linked existing models of surface and crown fire behavior to produce a system to assess the potential for crown fires at the stand level. In 1998 the modeling system was initially implemented in a Microsoft Excel spreadsheet. At the time the authors envisioned a short life-span for NEXUS as other more established programs incorporated similar modeling capabilities. In 2001 we updated the spreadsheet and produced an online user’s guide, but still did not envision a long life. In 2003, we obtained funding to re-code NEXUS as a stand-alone computer program, finally shedding the Excel spreadsheet interface. In 2014 the National Park Service funded the update of Nexus to version 2.1, enabling the software to work on computers running Windows 7 and 8 operating systems.

Installation file
The NEXUS2 installation file is nexus2.1.exe. Save this file to your machine and install from there; admin rights required. Alternatively, you may download the NEXUS21.zip archive which contains the installation program plus the associated readme.txt and releasenotes.txt files.

No Warranty
Because NEXUS 2.1 is licensed free of charge, there is no warranty for the program, to the extent permitted by applicable law. Except when otherwise stated in writing, the copyright holders and/or other parties provide the program “as is” without warranty of any kind, either expressed or implied, including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose. The entire risk as to the quality and performance of the program is with you. Should the program prove defective, you assume the cost of all necessary servicing, repair, or correction.