Quantifying human influence on fire ignitions across the western U.S.

Emily Fusco, University of Massachusetts, Amherst, efusco@cns.umass.edu (Presenter)
John Abatzoglou, University of Idaho, jabatzoglou@uidaho.edu
Jennifer Balch, University of Colorado-Boulder, jennifer.balch@colorado.edu
Bethany Bradley, University of Massachusetts, Amherst, bbradley@eco.umass.edu

Fire is a necessary disturbance in many of Earth's ecosystems, particularly in the western U.S. However, modern human societies have altered the spatial and temporal pattern of ignitions. Where fires were once started primarily by lightning, anthropogenic sources now drive many fire ignitions. Although many recent fires have been associated with humans, the spatial relationships between ignition events and human activity across landscapes and regions has not been explored in depth using the MODIS burned area record. Here, we quantify the relationship between human activity and non-lightning fire ignitions across the western United States. Using the MODIS Burned Area product to identify individual fire events, we isolated potential ignition points for all fires occurring from 2000-2012 based on the first date of burning within fire perimeters. To our knowledge, this is the first data set that utilizes remotely sensed data to determine the location of fire ignition points. We compared these points to the Vaisala National Lightning Detection Network data to determine if the ignition could be attributed to a natural lightning source. The remaining ignition points were considered to have been started anthropogenically. We modeled these non-lightning ignitions as a function of roads, powerlines, railroads, campgrounds, population density, and agriculture using the USGS SAGEMAP Human Footprint data source. Because the western U.S. varies greatly in climate and vegetation structure, we analyzed ignition data separately for seven western ecoregions. Using the derived spatial relationships, we aim to create a spatially explicit model of ignition pressure from anthropogenic and lightning sources across the western U.S. This information will be critical for predicting regional fire risk.

Presentation Type:  Poster

Session:  Theme 4: Human influence on global ecosystems   (Mon 4:30 PM)

Associated Project(s): 

• Balch, Jennifer: Understanding Climate and Land Use Drivers of Invasive-Grass Fueled Fires Across the Western U.S. ...details

Poster Location ID: 62