Human impact on coastal landscape: a diachronic analysis of wildland-urban interface in a Mediterranean area

During the last decades, Mediterranean areas have been affected by relevant modifications in the economic and social systems that have often produced transformations of the original landscape due to anthropization processes and land use changes. Large variations in residential expansion often occurred in coastal areas because of intensive tourism development. This is evident also in Sardinia, Italy, in particular in areas with high tourism potentials. In this areas and during the last fifty years, a large number of housing estates have been built near the coast, within and surrounded by natural vegetation, determining an important increase of wildland-urban interfaces (WUIs). From a geographical point of view, WUI indicates a variety of situations ranging from the expansion of urban areas towards the surrounding natural areas (classical WUIs) to the dissemination of buildings within natural areas. It is well known that Mediterranean shrubland is really prone to wildfire events. In addition, potential fire risk for villages, tourist resorts, other human activities and people increases during summer season, when human presence is larger, extreme weather conditions occur, and Mediterranean vegetation is more flammable. Recently, several authors showed that the analysis of trends in expansion of WUI and its impacts on fire risk is crucial for reducing and preventing fire risk and making decisions on future land use planning. Temporal pattern and recent rate of expansion of WUI have been rarely documented in European Mediterranean countries. This study, based on data and information over the period 1954-2008 focuses on evaluating the temporal evolution of presence and properties of WUI areas in three coastal areas located in North Sardinia, Italy, and characterised by large tourism development during the last fifty years. In particular, differences in WUI properties and dynamics among sites were examined and some implications of WUI expansion for fire risk were analysed.