Wildfire hazard maps are valuable tools for assessing risk to human populations and resources. While large, destructive wildfires in the United States occur more frequently in the arid West, the Northeast is also at risk from smaller (<50-acre) wildfires burning in the wildland-urban interface (WUI). However, mapping wildfire occurrence in the Northeast is challenging due to a lack of spatially accurate data documenting these small fire events. In this study, we mapped wildfire hazard on a state-by-state basis using a database of event locations aggregated from federal, state, and local incident reports. Our study area was the 20 states making up the USFS Northeast Region (Region 9). We used maximum entropy modeling (MaxEnt) to relate wildfire occurrence to land cover, vegetation type, population density, topography, distance to roads, protected areas, WUI classification, and climate. Maxent models were used to produce spatially continuous maps of relative wildfire occurrence probability. We repeated the modeling procedure to predict fire ignitions (i.e. wildfires of any size) as well as occurrence of larger wildfires (>10 acres).
Results/Conclusions
Preliminary results are for a subset of states with relatively complete fire reporting data spanning back to 2000 or earlier (New Jersey, New York, Minnesota, Wisconsin, and Michigan). While reporting records for small wildfires suffer from incompleteness, MaxEnt models were able to identify environmental drivers of wildfire using large numbers of known occurrences. Wildfire ignitions are strongly explained by presence of WUI and high human population densities, while larger wildfires are more common in protected areas with lower population densities. Temporal trends also show that annual number of wildfires and area burned are significantly correlated with drought metrics, suggesting that warming temperatures in the near future will affect wildfire risk in the Northeast. Spatially explicit hazard maps indicate where fire suppression resources are required to reduce area burned and risk to homes. Further work will focus on extrapolating hazard maps to all 20 states in the Northeast region.