1-km Wildland Urban Interface projections based on Shared Socioeconomic Pathways over the contiguous United States

Time-series maps of Wildland Urban Interface (WUI) categories and total wildland vegetation fraction at 1-km spatial resolution. 

WUI categories:

1 = intermix WUI (any gridcell with wildland vegetation fraction ≥ 0.5, population ≥ 11, and built (urban) land > 0)

2 = interface WUI (any gridcell with wildland vegetation fraction ≤ 0.5, population ≥ 11, built (urban) land > 0, and dense wildland vegetation (5+ connected gridcells with wildland vegetation fraction ≥ 0.75) within a 2-gridcell radius)

3 = populated areas not in proximity to wildland vegetation

4 = unpopulated dense wildland vegetation (population = 0, 5+ connected gridcells with wildland vegetation fraction ≥ 0.75)

5 = other

6 = rural (any gridcell with 0 < population < 11 which exist in proximity to wildland vegetation and do not qualify as intermix or interface WUI)

The time-series include the base year (2000) and projections (2001-2100), consistent with Shared Socioeconomic Pathways (SSPs) SSP3 and SSP5. NetCDF file format.

Any population and built land within a gridcell should be classified as the designated WUI category for that gridcell. WUI definitions are based off of Radeloff et al. (2018) and USDA (2001). The population and urban land use projections are from Gao (2020) and Gao (2021) respectively. Population and land cover are linearly interpolated to annual data from decadal projections, with population being rounded to the nearest whole number for use in the parameters of WUI categories.  

Wildland vegetation is derived from the U.S. Geologic Survey National Land Cover Database (NLCD) Land Cover. Total wildland vegetation fraction is a variable defined as the sum of NLCD categories 41, 42, 43, 52, 71, 90, and 95.

References:

Gao,  J. (2020). Global 1-km Downscaled Population Grids, SSP-Consistent Projections and Base Year, v1.01 (2000 - 2100) [Dataset]. Harvard Dataverse, V1. https://doi.org/10.7910/DVN/TLJ99B 

Gao, J. (2021). Global 1-km Downscaled Urban Land Fraction Grids, SSP-Consistent Projections and Base Year, v1 (2000 - 2100) [Dataset]. Harvard Dataverse, V1. https://doi.org/10.7910/DVN/0EGDOK

Radeloff, V. C., Helmers, D. P., Kramer, H. A., Mockrin, M. H., Alexandre, P. M., Bar-Massada, A., Butsic, V., Hawbaker, T. J., Martinuzzi, S., Syphard, A. D., & Stewart, S. I. (2018). Rapid growth of the US wildland-urban interface raises wildfire risk. Proceedings of the National Academy of Sciences, 115(13), 3314–3319. https://doi.org/10.1073/pnas.1718850115 

U.S. Geological Survey. (2024). National Land Cover Database (NLCD) 2006 Land Cover Conterminous United States (ver. 2. 0, July 2024) [Dataset]. U.S. Geological Survey data release. https://doi.org/10.5066/P9HBR9V3 

USDA, & USDI. (2001). Urban Wildland Interface Communities Within the Vicinity of Federal Lands That Are at High Risk From Wildfire. Federal Register, 66, 751–777.