Spatial analysis of ignition point patterns and the probability of fire occurrence in the western area of Neuquén province

MUNDO, I.A.; WIEGAND, T.; KITZBERGER, T.

Bariloche

Congreso; VI Southern Connection Congress; 2010

Southern Connection

The spatial pattern of fires occurrence is an important feature in the fire dynamics studies helping to understand how fire can shape or modify the structure and composition of the vegetation communities at a landscape scale. Our objectives were 1) to characterize the spatial pattern of fire ignitions (855 points) in the western area of Neuquén (1992-2008), 2) to analyze the spatial association of climatic, accident-negligence and arson caused fires to towns and 3) to map fire ignition probabilities based on topographic, climatic, land cover and anthropogenic map variables. Univariate and bivariate point pattern analyses were conducted by means of the O-ring statistic. Maps of ignition probabilities were derived through stepwise logistic regression. The distribution of observed number of ignitions in each land cover type differed significantly from the expected number. The steppe, wetlands, forest plantations and urban areas presented more ignitions than expected. The spatial pattern of total ignitions showed a non homogeneous distribution. A positive interaction between total ignitions and towns was observed at distances shorter than 5 Km. The fire probability model that included all variables reached the best adjustment (AUC:0.854-overall correctness:77.7). Based on the strong relationship between human variables and fire ignitions and considering the expected demographic growth in Neuquén, an increase in the area affected by fire is highly expected during the XXI century.