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Assessing the risk of forest fires in wildland urban interfaces (WUIs) is crucial for wildfire prevention and land management. With the goal of developing an efficient management of fire risk in wildland urban interfaces in European Mediterranean countries, this chapter recommends methods and advices for the identification, characterization and mapping of WUIs as well as for the assessment of the fire hazard, the vulnerability and the damage potential of these areas. These tools are the result of scientific researches and fruit of past experiences analysis. More over this chapter insists on the interest of providing wildland urban interface maps in the purpose to know the real extent of theses areas and to manage their development. It briefly presents the steps of a method to identify, to characterize and to map WUI in European Mediterranean countries combining relevant criteria which are connected to the spatial organization of inhabitant dwellings and the structure of the vegetation. A WUI' typology is established. The method can be easily applied by land agencies or managers easily and is suitable both in large areas or landscape level (small scales) and in local conditions (large scale). Because of their high vulnerability, ignition probability and combustibility, it is important and efficient to focus risk assessment in the WUIs. The chapter brings a method to assess and to map fire hazard levels and vulnerability levels according to WUIs and their environment. Introducing the risk of fire and particularly the vulnerability of the territory with such maps is a way to make the inhabitants becoming aware of fire risk in WUI. This will globally decrease the risk of fire either by reducing fire propagation with biomass removal and or by reducing fire ignition probability together with less carelessness. Accomplishing this goal is strictly related to the designation of suitable prevention messages and preventive actions which can be different according to WUI types.

The paper presents the major outcomes of the produced guide. It particularly describes the method developed for mapping WUIs on large areas and at large scale in the European Mediterranean context. The method used remote sensing and spatial analysis tools. Particularly adapted to the French context, it can be easily adapted according specific contexts observed in different European countries. After specifying accurate definition of wildland-Urban Interface (WUI), a WUI typology was based on the combination of four housing configuration types and three natures of horizontal structure of vegetation determined through objective and quantitative criteria. Housing configuration reveals spatial organization of residential dwellings: isolated, scattered, dense clustered and very dense clustered housing. Horizontal structure of vegetation points out the continuous vegetation, the sparse vegetation or the no existing vegetation in contact with houses. Twelve wildland-urban interface types were produced.In parallel a software tool was developed and briefly presented in the paper in order to map WUIs as automatically as possible. The production of WUI maps presents high interest for quantification of the extension of WUIs on the territory, main characteristics of WUIs, assessment and mapping of fire risk levels in WUIs. The main objective of the guide is to help end-users such as land managers, foresters and fire-fighters to locate WUIs on the ground with a view to develop specific actions for wildfires prevention according to WUI types, to create public awareness programs for inhabitants faced with wildfire risk, and to assess fire fighting difficulties due to urbanization.

Presentation of main results of Fire paradox concerning wildland-urban interfaces., Présentation des travaux de Fire paradox relatifs aux interfaces habitat-forêt.

Effect of prescribed burning on the mitigation of fire risk was discussed in fire prone ecosystems of three European countries (Greece, France and Portugal). Two study cases were presented using two different fire modelling approaches, the spatial fire growth model FARSITE and FIRETEC a physically based fire propagation model. This study showed that fuel management with prescribed burning had a significant effect on fire propagation hazard. It needs to be completed with further studies on prescribed burning effects on the other fire risk components such as ignition likelihood or vulnerability (fire effects on trees). First results also showed the need of optimizing the spatial pattern of fire application both when applied extensively on the landscape, and when located on a fuel break network. The first study case concerned a conifer forest located in Kassandra peninsula in northern Greece, which has been affected by a 7120 ha wildfire in August 2006. Prescribed burning effectiveness was assessed by using the FARSITE simulator for comparing fire spread over the landscape before and after prescribed burning application on a network of stripe-shaped fuel-breaks. Analysis showed a significant reduction of fire potential (fireline intensity, flame length and total burned area) as a result of fuel treatments. The second study case concerned a shrubland and woodland mosaic in limestone Provence, France, where prescribed burning has been used as a fuel reduction tool for more than 15 years The effectiveness of prescribed burning was assessed by comparing fire potential (rate of spread, fireline intensity) before and in the years following prescribed burning treatments. Analysis carried out at the stand scale gave valuable information on the immediate potential fire hazard reduction after prescribed burning. In order to estimate the appropriate prescribed burning return interval, two management scenarios were used (i) a fire intensity threshold compatible with efficient and safe fire fighting or (ii) a shrub encroachment threshold easy to assess by forest managers. In both cases, the prescribed burning return interval varied from 2 to 3 years, depending on fuel types. When applying prescribed burning on a 15 years period, fire risk mapping on the whole State forest showed a higher fire risk reduction when using the fire intensity threshold than a fuel encroachment threshold. A third study case in the Portuguese mainland tested an important assumption of the fire paradox: does fuel age have an influence on burn probability and wildfire size? Fire frequency analysis of mapped fire perimeters ≥10 ha (1998-2008) indicated that fire occurrence was weakly to moderately dependent of fuel age. However, contrarily to the usual expectation, age-dependency did not decrease for larger fire size classes (i.e with increasingly extreme fire weather). Finally, we explored the variation in fire size statistics with fuel age. Older fuels (roughly >8 years after burning) were associated to more variable fire sizes, allowing much larger wildfires. From the results we infer that landscapes submitted to a mean prescribed fire return interval of 4 years will not support wildfires larger than 500 ha. However, adequate spatial planning of the treatments is expected to reduce the annual treatment rate. This deliverable contributes to solving the Fire Paradox because it clearly shows how fuel modification can decrease wildfire hazard and severity which is the first specific objective to be addressed in Integrated Wildland Fire Management. The state of the art chapter has shown that several fuel modification techniques, such as mechanical treatments, are available and used in Europe, but it has also demonstrated that prescribed burning although being increasingly used in some countries, still has to be strongly supported with the objective of the wisest complementarities between fuel treatments. Also, prescribed burning is the approach based on the paradox of fire, reducing fuels strategically before they can be used by wildfires, thus decreasing wildfire risk and severity

Large areas initially consisted of contiguous forests, particularly in Europe, have been influenced by human activities to a large extent. This influence contributed to the fragmentation of the rural landscape and forested areas were found surrounded by or intermixed with urban development. Urban and economic development in or near wildland vegetation poses a major threat to the environment (Johnson 2001, Radeloff et al. 2005). They are areas of humanenvironment conflicts, such as the destruction of homes by wildfires, natural habitat fragmentation, introduction of exotic species, and biodiversity decline (Radeloff et al. 2005). These areas that characterized of increased human activities and land use conversion make up the Wildland/Urban Interfaces. The significance of Wildland/Urban Interfaces (WUIs) has grown in recent years mainly because WUI, as a landscape unit, has grown worldwide (Steward et al. 2003). Essentially in USA, Canada and Australia interest for WUI study appeared after the huge fires of 1985 in the WUI (Davis, 1990) and in Europe this interest appeared ten years ago with increasing of damages on goods and people due to WUI fire. Large efforts aiming at the identification and mapping of existing or potential wildland urban interface areas have already been recorded in North America but they have to be developed in Europe. In the European project Fireparadox, several research and engineering teams are working together with a view to develop a methodology to characterize and to map WUI through spatial analysis of the territory according to regional and local approach. The objective at term is to be able to assess and to map vulnerability level or index according to each WUI types and also damages in case of fire. Theses results will allow to develop appropriated prevention actions, to help firefighters adapting their fighting strategy (concentration or dispersal of crews and facilities according to the stakes, positioning on the most vulnerable zones of interface ). The presentation presents an application of the method of WUI characterization and mapping on a case study area in Sardinia.