International Journal of Wildland Fire International Journal of Wildland Fire Society
Journal of the International Association of Wildland Fire

Temporal and spatial structure in a daily wildfire-start data set from the western United States (1986–96)

P. J. Bartlein A F , S. W. Hostetler B , S. L. Shafer C , J. O. Holman B D and A. M. Solomon E
+ Author Affiliations
- Author Affiliations

A Department of Geography, University of Oregon, Eugene, OR 97403-1251, USA.

B US Geological Survey, Department of Geosciences, Oregon State University, Corvallis, OR 97331, USA.

C US Geological Survey, 3200 SW Jefferson Way, Corvallis, OR 97331, USA.

D TerraSeer, Inc., 516 N. State St., Ann Arbor, MI 48104, USA.

E US Department of Agriculture, Forest Service, Arlington, VA 22209, USA.

F Corresponding author. Email:

International Journal of Wildland Fire 17(1) 8-17
Submitted: 11 November 2006  Accepted: 21 September 2007   Published: 14 February 2008


The temporal and spatial structure of 332 404 daily fire-start records from the western United States for the period 1986 through 1996 is illustrated using several complimentary visualisation techniques. We supplement maps and time series plots with Hovmöller diagrams that reduce the spatial dimensionality of the daily data in order to reveal the underlying space–time structure. The mapped distributions of all lightning- and human-started fires during the 11-year interval show similar first-order patterns that reflect the broad-scale distribution of vegetation across the West and the annual cycle of climate. Lightning-started fires are concentrated in the summer half-year and occur in widespread outbreaks that last a few days and reflect coherent weather-related controls. In contrast, fires started by humans occur throughout the year and tend to be concentrated in regions surrounding large-population centres or intensive-agricultural areas. Although the primary controls of human-started fires are their location relative to burnable fuel and the level of human activity, spatially coherent, weather-related variations in their incidence can also be noted.

Additional keywords: annual cycle of fires, fire incidence, Hovmöller diagram, human-caused fires, lightning-caused fires, time–space plots, time–space variation, US National Fire Occurrence Database, wildfire outbreaks.


The present research was supported by the Joint Fire Sciences Program (BLMIA 1422RAI01–0040), NSF grants ATM-9910638 and ATM-0117160, and the US Geological Survey Water Resources Division and Earth Surface Dynamics Program. The National Fire Occurrence Database was obtained from the Fire Sciences Laboratory, Rocky Mountain Research Station, USDA Forest Service website at We thank two anonymous reviewers and R. S. Anderson for comments.

Contributions: All authors contributed to the overall conceptual design of the analysis, and to the final manuscript. Bartlein created the figures, Bartlein, Hostetler and Shafer drafted the manuscript, and Holman contributed to the data analyses.


Bartlein PJ, Hostetler SW, Shafer SL, Holman JO, Solomon AM (2003) The seasonal cycle of wildfire and climate in the western United States. In ‘5th Symposium on Fire and Forest Meteorology, 16–20 November, 2003, Orlando, FL, USA’. Paper P3.9. (American Meteorological Society: Boston, MA)

Brown TJ, Hall BL, Mohrle CR, Reinbold HJ (2002) Coarse assessment of federal wildland fire occurrence data. Desert Research Institute, Program for Climate, Ecosystem and Fire Applications, Report CEFA 02–04. Available at [Verified 4 January 2008]

Cleveland WS (1993) ‘Visualizing data.’ (AT&T Bell Laboratories: Murray Hill, NJ)

Hardy CC, Schmidt KM, Menakis JP , Sampson RN (2001) Spatial data for national fire planning and fuel management. International Journal of Wildland Fire  10, 353–372.
CrossRef |

Hostetler SW, Bartlein PJ, Holman JO, Solomon AM, Shafer SL (2003) Using a regional climate model to diagnose climatological and meteorological controls of wildfire in the western United States. In ‘5th Symposium on Fire and Forest Meteorology, 16–20 November, 2003, Orlando, FL, USA’. Paper P1.3. (American Meteorological Society: Boston, MA)

Hostetler SW, Bartlein PJ, Holman JO (2006) Atlas of climatic controls of wildfire in the western United States. US Geological Survey Scientific Investigations Report 2006–5139. Available at [Verified 4 January 2008]

Hovmöller E (1949) The trough and ridge diagram. Tellus  1, 62–66.

Nash CH , Johnson EA (1996) Synoptic climatology of lightning-caused forest fires in subalpine and boreal forests. Canadian Journal of Forest Research  26, 1859–1874.

Rorig ML , Ferguson SA (1999) Characteristics of lightning and wildland fire ignition in the Pacific Northwest. Journal of Applied Meteorology  38, 1565–1575.
CrossRef |

Schmidt KM, Meanakis JP, Hardy CC, Hann WJ, Bunnell DL (2002) Development of coarse-scale spatial data for wildland fire and fuel management. USDA, Forest Service, Rocky Mountain Research Station, General Technical Report RMS-GTR-87. (Fort Collins, CO) 41 pp. + CD.

Schroeder MJ, Buck CC (1970) ‘Fire Weather, Agricultural Handbook 360.’ (USDA Forest Service: Washington, DC)

Skinner WR, Stocks BJ, Martell DL, Bonsal B , Shabbar A (1999) The association between circulation anomalies in the mid-troposphere and area burned by wildland fire in Canada. Theoretical and Applied Climatology  63, 89–105.
CrossRef |

Swetnam TW , Betancourt JL (1998) Mesoscale disturbance and ecological response to decadal climatic variability in the American South-west. Journal of Climate  11, 3128–3147.
CrossRef |

Westerling AL, Gershunov A, Brown TJ, Cayan DR , Dettinger MD (2003) Climate and wildfire in the western United States. Bulletin of the American Meteorological Society  84, 595–604.
CrossRef |

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