7th Workshop on Forest Fire Management - EARSeL, European ...

First steps towards a long term forest fire risk of Europe 81
Martinez et al. (2009) applied the historical values of the cumulative number
of fires divided by the forest area of municipalities. Alternatively,
records of fire events with coordinates can be used to analyse point location
patterns (Catry et al., 2007) and apply a weighted probability to the
distribution of the points for which there are no coordinates.
For the purpose of this study, the distribution of ignition points with coordinates
in Portugal, the country with the longest series of fire data, was
analysed in view of the land cover. Between 2001 and 2007, Portugal
recorded 133411 IP. The land cover of each IP was retrieved based on
Corine Land Cover (CLC) 2000 (25 m). Additionally, it was also obtained the
correspondent category of the Pan-European Forest/Non-Forest Map 2000
(25 m) (Pekkarinen et al., 2009).
Considering Corine Land Cover data, it was found the following:
• The number of ignition points in each CLC category does not correspond
to the surface area occupied by each land cover in the country. Chisquare
test was applied in order to verify if there was any difference
between the observed and the expected number of ignition points per
land cover class (χ2 = 895.006, df=40, p90% than
expected) and Agricultural Areas (heterogeneous agricultural areas -
>74% than expected).
• CLC classes were assembled into larger groups based on the fire domain
defined in EFFIS. IP density was calculated based on the number of
points per km2 in each fire domain group. Artificial surfaces show the
higher density, followed by agriculture (Fig. 1).
Figure 1 - Density of ignition points per land use group.