This dataset was developed for the 2015 Assessment of Forest and Rangelands. It is derived from

several data sources, including housing density (input_lsn_HousingDensity12_2), Fire Hazard

Severity Zones (FHSZ_Assessment11_1), Unimproved Parcels (input_UnimprovedParcels16_1),

and Vegetation Cover (input_FVEG15_2). The current dataset is appropriate for displaying the overall

pattern of WUI development at the county level, and comparing counties in terms of development patterns.

Until the dataset is refined through a field review process, it is not suited for WUI designations for individual

houses or neighborhoods.

Housing Density Classes used in the WUI definitions:

1 - Less than one house per 20 acres

2 - One house per 20 acres to one house per 5 acres

3 - More than one house per 5 acres to 1 house per acre

4 - More than 1 house per acre

Wildland Urban Interface is dense housing adjacent to vegetation that can burn in a wildfire and must meet

these criteria:

•Housing density class 2, 3 or 4

•In moderate, high, or very high Fire Hazard Severity Zone

•Not dominated by wildland vegetation (i.e., lifeform not herbaceous, hardwood, conifer or shrub)

•Spatially contiguous groups of 30m cells that are10 acres and larger

Wildland Urban Intermix is housing development interspersed in an area dominated by wildland

vegetation subject to wildfire and must meet these criteria:

•Not Interface

•Housing density class 2

•Housing density class 3, 4 dominated by wildland vegetation

•In Moderate, High or Very High Fire Hazard Severity Zone

•Improved parcels only

•Spatially contiguous groups of 30m cells 25 acres and larger

Wildfire Influence Zone is wildfire susceptible vegetation up to 1.5 miles from Wildland Urban Interface or

Wildland Urban Intermix and must meet these criteria:

•Wildland vegetation up to 1.5 miles from Interface or Intermix