Western Wildlands Environmental Threat Assessment Center Wildfire Risk Analysis and Fuel Treatment Planning Alan Ager, Western Wildlands Environmental Threat Assessment Center, Prineville Oregon, OR USA Mark Finney, Rocky Mountain Research Station, Missoula MT John Anderson, BalanceTech Inc., Missoula, MT Helen Maffei, Deschutes National Forest, Bend, OR

Western Wildlands Environmental Threat Assessment Center The Problem Landscape fuel treatment planning is a complex process –Multiple scales –Multiple models –Data and model integration is weak –Wildfire occurrence is highly stochastic – we cannot predict future wildfire likelihood with any certainty –We don’t have a well established analysis process and performance metrics

Western Wildlands Environmental Threat Assessment Center Risk analysis as a framework for fuel treatment planning Simple case, only consider losses: Expected Loss = probability of event * loss For multiple loss events of different intensities and probabilities Expected loss = Σ (probability j * loss j ) Consider both benefits and losses of multiple events (also present and future) Expected Net Value Change = (probability j * net value change j ) Definition of Risk:

Western Wildlands Environmental Threat Assessment Center Umatilla National Forest Fire History The majority of acres burned are from a few large fires that escape initial attack and spread over long distances Wildfire probability is largely a function of wildfire spread

Western Wildlands Environmental Threat Assessment Center Loss Functions are required to link fire intensity with loss

Western Wildlands Environmental Threat Assessment Center Mitigate Risk by: Reducing wildfire probability Reducing fire intensity Change the loss function

Western Wildlands Environmental Threat Assessment Center Wildfire Risk Analysis Process for Fuels Planning Design stand fuel treatments (FVS, FFE, SVS) Design landscape treatment package (ArcGIS) Simulate treatments (PPE) and generate FlamMap landscape files Calculate Burn probabilities by simulating lots of wildfires (FlamMap) Calculate loss functions (FVS-FFE) Calculate expected loss (Access queries) Compare treatment alternatives

Western Wildlands Environmental Threat Assessment Center Emily Ager Five Buttes Oregon Case Studies

Western Wildlands Environmental Threat Assessment Center Five Buttes Study Area, Deschutes National Forest

Western Wildlands Environmental Threat Assessment Center Burn Probability - No treatments, 2000 wildfires, 24 hour burn periods > 0.045

Western Wildlands Environmental Threat Assessment Center 17,000 acre fires Size of fires generated from random ignitions 2500 acre fires

Western Wildlands Environmental Threat Assessment Center Stands selected for fuel treatment, 20% of landscape treated Owl habitat stands treatments

Western Wildlands Environmental Threat Assessment Center 0% treatment 10% treatment 20% treatment 50% treatment

Western Wildlands Environmental Threat Assessment Center Burn probability does not indicate loss Need to calculate expected loss, the probability of a fire and loss of habitat

Western Wildlands Environmental Threat Assessment Center Out of 1000 simulated fires on pixel X,Y, how many eliminate owl habitat? Lethal flame length ~100 fires have flame lengths that exceed the lethal flame length Expected loss = 100/10000 = 0.01

Western Wildlands Environmental Threat Assessment Center Calculate the lethal flame length for owl habitat stands Simulated fire in each stand with flame lengths ranging from meters, 0.5 meter increments [ FLAMEADJ ] Determine the flame length when the stand at no longer meets habitat requirements Query these results against the FlamMap output table

Western Wildlands Environmental Threat Assessment Center

Expected Loss of Spotted Owl Habitat for 6 Treatment Intensities

Western Wildlands Environmental Threat Assessment Center Summary: Risk Analysis in Fuel Treatment Planning Provides a quantitative measure of fuel treatment performance Accounts for fire spread, intensity, and loss Can incorporate multiple future and present losses and benefits

Western Wildlands Environmental Threat Assessment Center The WO-SPOT and R5 Fireshed Assessment Process Quantitative Framework for Wildfire Risk WWETAC, JFSP (Miller, Ager, Finney, Parisien) ArcFuels FVS, FFE, PPE FlamMap, Behave, FOFEM, Nexus,

Western Wildlands Environmental Threat Assessment Center ArcFuels VBA macros in ArcMap Implemented on 2 toolbars ArcObjects library allows full GIS functionality Distributed in an.MXD project file Macro errors do not crash ArcMap Hooks to Excell, Access, FVS, FlamMap, Farsite, Nexus, SVS, Behave Interface