Fire risk assessment on the french mediterranean coast.
Reaching regional scale using high resolution remote sensing and combining spatial indexes.

Laurent Borgniet, Marielle Jappiot, Corinne Lampin, Marlène Long

UR Ecology and Risks in the Mediterranean, Cemagref, (F)

Abstract

Our study takes place in the special context of the recent summer events (2003-04) with extrem heat periods and larges fires in Provence Alpes-Côtes d'Azur region, and especially on touristic and suburban coastal zones .
We consider it as the result of two basical phenomena conjunction. On one hand, urban sprawl takes place from the french mediterranean coastline towards the natural landscape in the back country where, on the other hand, forest and garrigue densify and biomass increases.
On the coast between the metropolitan area of Marseille and the riviera (Ste Maxime) we detect and localize new urban or artificial zones, becoming sources of fire eclosion and developping higher vulnerability.
Then we develop a method to recognize the boundaries of homogenous spaces (fine and middle scales) on the contacts between urban extension and natural landscapes. The aim is to qualify these complex interface zones in the more objective and automatical way. Based on high resolution images (Spot5) treatments and accurate topographical mapping, we create spatial indexes taking in account parameters of texture, topological caracteristics and urban planning GI attributes.
The final objective is to link this high resolution information on fire eclosion with vegetation combustibility and fire propagation.
Achievement of this knowledge integration in a 3D GIS represent an urgent challenge and still a extense domain of investigation.