Periurban landscapes in metropolitan areas: exploring land cover dynamics across typologies

Peri-urban areas have been conceptually framed as encompassing both characteristics of the urban and rural world and to be located somewhere in-between the urban core and the rural landscape. From a spatial perspective an urban–rural gradient is pointed out generally grounded on the urbanization process and the patterns of urban cover. In an attempt to characterise the key features of peri-urban areas surrounding Lisbon (Portugal), a multidisciplinary panel identified the main dimensions setting the character of peri-urban landscapes which, together with the input of local and regional stakeholders, led to the mapping of a typology for the 211 parishes (LAU 2 Level) in Metropolitan Area of Lisbon (MAL). Here, based on CORINE Land Cover data for 1990 and 2006, a cluster analysis was applied to identify major land cover patterns and dynamics in the multidisciplinary typologies of parishes within the MAL, using both a static view of the 2006 land cover map and a dynamic view based on the changes occurring during the 1990-2006 period. Seven different types of parishes could be identified in 2006, which vary foremost according to the composition and diversity of land cover categories and landscape fragmentation. It stands out that for 4 types, even though with similar urban presence, significant differences can be found due to varying combinations of the agriculture mosaic, annual and permanent crops, wild land and other artificial land cover classes. Those types are mostly formed by the interaction between the different classes and fragmentation of the landscape, demonstrating that that there is no clear-cut urban-centric model that forms the urban-rural gradient, singularly explained by the quantitative increase of urbanized area. This argument becomes even stronger when observing the 1990-2006 dynamics. In spite of a general increase in urbanized area, land cover changes are not fully explained by a transition of agriculture or wild lands to urban. Furthermore, urbanization processes (consolidation, expansion or spot spreading) are not the sole drive of change, but there are simultaneously other processes taking place that suggest an intensification and specialization of agriculture, or the settlement of other artificial areas (e.g., major infrastructures and facilities) on former agricultural land.