Susan Smith has worked as an editor and writer in the technology industry for over 16 years. As an editor she has been responsible for the launch of a number of technology trade publications, both in print and online. Currently, Susan is the Editor of GISCafe and AECCafe, as well as those sites’ … More »
2019 Wildfire Risk Report from CoreLogic Analyzes Western U.S. Damage and Risk
October 16th, 2019 by Susan Smith
In September, CoreLogic released their 2019 Wildfire Risk Report that analyzes the top regions, states and metro areas at risk for wildfire damage, including number of at-risk homes and their estimated reconstruction costs. The report also includes a breakdown of 2017 and 2018’s major wildfires, which were quite extensive through the western United States. The report focuses on homes in the western states including Arizona, California, Colorado, Idaho, Montana, New Mexico, Nevada, Oklahoma, Oregon, Texas, Utah, Washington and Wyoming.
Some important facts from the report include (from company materials):
Tom Jeffery, Senior Hazard Scientist, CoreLogic Spatial Solutions, spoke with GISCafe Voice about the results of the report and how they evaluate the risk of wildfires.
What determines what are ranked high-risk for wildfires?
Higher wildfire risk is closely associated with fuels that are likely to generate intense, high-heat fires. All vegetation will burn, but not all at the same level of heat energy. It is important to distinguish which fuels, based on species, density, and fuel load, are most likely to result in a high level of heat release. In addition, terrain plays a role as well, as it can affect how a fire moves through an area and how fuels are affected.
How did the risk factor for 2018 and 2017 compare with the risk factor for 2019?
We didn’t put out a wildfire risk report in 2017 or 2018, but in general, we don’t compare year-over-year risk factors because changes between the number of homes at risk and the reconstruction cost value (RCV) can be the result of several variables, including new home construction, improved public records, enhanced modeling techniques, fluctuation in labor and equipment and material costs. For that reason, direct year-over-year comparisons should be warily considered. With that said, we do know that some new construction continues to put homes in areas of higher wildfire risk. Due to the fact that new residential construction often occurs at the edge of current development (the Wildland-Urban Interface), it is likely that there will be an increase in the number of homes at risk from wildfires as the number of single family residential properties increases every year.
How do you assess the risk score?
The wildfire risk is based on combining fuels (vegetation) with terrain factors and also fire history. Then we use the CoreLogic ParcelPoint database to pinpoint properties located in or near areas exposed to potential damage or destruction from a wildfire event.
This enables us to interpret the risk posed by either direct flame contact or the radiant heat generated by a fire in very close proximity to a structure. The evaluation is also based on distance measurements to nearby patches of fuel (vegetation) and wildland that could be the source of airborne embers. Embers are an especially important consideration since they often originate within the body of the main burn that may be relatively distant from the structure, but the embers can land on or near the structure and cause a direct ignition.
To determine residential exposure value, CoreLogic parcel-level data is paired with the proprietary CoreLogic Wildfire Risk Analysis to identify every property contained within each separate wildfire risk category. After matching each residential property to a structure valuation, the values are totaled by risk category within individual geographic areas. The final results illustrate the total number of residential properties at risk (Low, Moderate, High, Extreme), as well as the total current reconstruction cost value of those properties.
What are insurance companies concerned with when they consult with you?
Insurance companies are often concerned with aggregation of risk. Understanding how many homes they are insuring in areas of high risk, enables them to spread their policies throughout various locations without concentrating all of their potential losses in one area.
In looking at the properties, is one of the factors that you taking into account in terms reconstruction costs, the cost of the area in terms of real estate?
To estimate the value of property exposure of single-family residences, CoreLogic uses its RCV methodology, which estimates the cost to rebuild the home in the event of a total loss and is not to be confused with property market values or new construction cost estimation. In addition, the RCV does not take into account the value of the land on which the home resides. The figures used as “values” in the tables and graphs throughout this report reflect the current reconstruction cost value, which is based on the cost of materials and labor and also factors in the pricing variations for both that occur due to different geographic locations in these wildfire states. The values in this report are based on 100% percent destruction of the residential structure.
Do you have your own geographic information system?
CoreLogic utilizes current state of the art GIS systems as part of the analysis of wildfire risk. While we do not create our own GIS software, we do use 3rd party GIS software and develop our own custom applications and coding that enable us to produce our proprietary risk solutions.
Do you think people will stop building homes in areas with high to extreme wildfire risk or that they will continue to take their chances to lose millions of dollars in property?
It’s certainly people’s prerogative to live where they want to within the law. It’s hard to say whether or not people will continue to assume the risk of living in areas with high wildfire exposure, but we hope our Wildfire Risk Report helps educate homeowners and insurers on what they’re facing so they can make decisions that make the most financial sense for them. An equally important consideration is that wildfire risk can be dramatically reduced if homeowners implement mitigation strategies to minimize the likelihood that a fire will ignite their home. In areas of high wildfire risk, mitigation has been proven to reduce structure ignitions and can be effective at reducing the overall impact of wildfires on residential properties. While there is no guarantee the mitigation will eliminate wildfire risk, for homeowners who desire to live in higher risk areas, mitigation offers them the option of taking steps to reduce the potential for wildfire damage.
With your methodology, how accurate were you in your risk assessment on the 2018 fires and others?
One of our standard procedures is to evaluate our risk assessment in areas that have recently burned. By correlating the wildfire risk for properties (pre-fire) with the homes/structures that were damaged or destroyed by a particular fire, we are able to gain a more precise evaluation of the accuracy of our data. For example, in the aftermath of the Camp Fire in California in 2018, we determined that 99.1% of the properties that were damaged or destroyed were identified as either Moderate, High or Extreme wildfire risk by our data, with 98% falling into the top 2 categories of High and Extreme. California’s Carr Fire, also in 2018 indicated that 97.3% of the damaged/destroyed structures fell into the Moderate, High or Extreme categories. Just as wildfires are all quite unique in how and where they burn, we do see the aftermath analysis vary, but is often well above 95% in terms of correlating High and Extreme risk with structures that are damaged or destroyed. We have not yet evaluated any fires in 2019, but will be doing so for the Saddle Ridge and Sandalwood Fires in California.
Congratulations to Marcin Pinkosz, a student of the 2nd year of engineering studies in Spatial Management at the Warsaw University of Technology. Marcin won the GISCafe Sweepstakes at Intergeo in Germany.
Marcin is a board member of the Warsaw University of Technology Scientific Association of Spatial Management and the president of the Orczyk Ski Association. For many years he has been interested in the subject of transport, skiing, geography and cartography and as a student I actively use GIS tools.