Look for complete geospatial metadata in this layer's associated xml document available from the download link

* Metric Name: Structure Exposure Score   

* Tier: 1  

* Data Vintage: 08/2023. Includes disturbances through the end of 2022  

* Unit Of Measure: Relative index, 10 classes, low to high exposure  

* Represent element and pillar: No  

* Type and distribution of data: Asymmetric distribution representing index values. The raw data range from 3 and 30.  

* Translation: Where is structure exposure to fire low?  

* Translation method and outcome: Raw data values translated to range from +1 to -1 representing more favorable to less favorable conditions, respectively. **** The proposition of more favorable is based on the objective of lower structure exposure (negative linear slope). More favorable (translated to +1) set at 1.0, less favorable (translated to -1) set at > 30\. Alternative approaches could be to set -1 at the top value, but that would result in a more favorable interpretation of structure exposures. 

Figure 61. Histogram and scoring criterion of structure exposure score across
Southern California

Figure 62. Histogram of translated structure exposure score across Southern
California

Figure 63. Maps displaying raw metric and translated metric structure exposure
score across Southern California

  

* Metric Definition and Relevance: This metric combines two data layers; one is the Wildland Urban Interface (WUI) as defined by Carlson et al. 2022, and a second data layer, Structure Exposure Score (SES), developed by Pyrologix LLC. The WUI includes the intermix and interface zones which collectively identify areas where structures occur. The distance selected for the interface definition is based on research from the California Fire Alliance indicating the average distance firebrands can travel from an active wildfire front. Structure Exposure Score is an integrated rating of wildfire hazard that includes the likelihood of a wildfire reaching a given location along with the potential intensity and ember load when that occurs. SES varies considerably across the landscape. The data are current through 2021. Not included in the element representation because it is included in the calculation of damage potential.

Pyrologix uses a standard geometric-interval classification to define the ten
classes of SES, where each class break is 1.5 times larger than the previous
break. So, homes located within Class X are 1.5 times more exposed than those
in Class IX, and so on. This metric represents SES for WUI areas only.

  

* Credits: Pyrologix, LLC, WUI (USGS)