Characterizing configurations of fire ignition points through spatiotemporal point processes
C. Comas1, S. Costafreda-Aumedes2, and C. Vega-Garcia21Department of Mathematics, University of Lleida, Agrotecnio Centre, Spain 2Department of Agriculture and Forest Engineering, University of Lleida, Spain
Received: 14 Mar 2014 – Accepted for review: 22 Mar 2014 – Discussion started: 28 Apr 2014
Abstract. Human-caused forest fires are usually regarded as unpredictable but often exhibit trends towards clustering in certain locations and periods. Characterizing such configurations is crucial for understanding spatiotemporal fire dynamics and implementing preventive actions. Our objectives were to analyse the spatiotemporal point configuration and to test for spatiotemporal interaction. We characterized the spatiotemporal structure of 984 fire ignition points in a study area of Galicia, Spain, during 2007–2011 by the K-Ripley's function. Our results suggest the presence of spatiotemporal structures for time lags of less than two years and ignition point distances in the range 0–12 km. Ignition centre points at time lags of less than 100 days are aggregated for any inter-event distance. This cluster structure loses strength as the time lag increases, and at time lags of more than 365 days this cluster structure is not significant for any lag distance. Our results also suggest spatiotemporal interdependencies at time lags of less than 100 days and inter-event distances of less than 10 km. At time lags of up to 365 days spatiotemporal components are independent for any point distance. These results suggest that risk conditions occur locally and are short-lived in this study area.
Comas, C., Costafreda-Aumedes, S., and Vega-Garcia, C.: Characterizing configurations of fire ignition points through spatiotemporal point processes, Nat. Hazards Earth Syst. Sci. Discuss., 2, 2891-2911, doi:10.5194/nhessd-2-2891-2014, 2014.