Spatial and temporal land use change and occupation over the last half century in a peri-urban area

Understanding the reorganisation of land in order to adapt its use and spatial structure to social demands has become crucial to management and represents a major challenge to land use planning and public policies. This study explores the temporal and spatial land use change transitions in a peri-urban area of a medium-sized city located in the central Portugal and characterised by profound changes in the last half century. The study is supported by a collection of seven years/moments of image analysis (the 1958, 1973, 1979, 1995, 2002 and 2007 maps). Cross-referencing the successive sets of images defines the percentage of land transition and provides the stability grade (SG), which expresses the total proportion of the landscape that has not experienced any transition to a different category of land use. In order to evaluate the intensity of urban expansion, an annual rate of artificialisation of surfaces (AS) indicator was used. The seven cartographic outputs highlight a decrease in the area occupied by permanent crops, an increase in urban areas, especially the continuous urban fabric, a large forest occupation involving different typologies and paths, and an increase in base soil areas. The data also shows a general increase in the number of patches recognised and in pattern complexity. The results show that land use changes are created by systematic transitions, with or without gross variations, and also by casuistic processes associated with an increase in artificialised areas and the growth of the continuous urban fabric. Land use transition reflects the internal and external inputs associated with the approval of Municipal Master Plans and the land regulatory regime, and also the consolidation of the road infrastructure network. The analysis indicates that the transfer takes place in a set of small sequential steps marking the evolution from rural characteristics to a process of peri-urbanisation, ending in urban consolidation.

► Land use transitions in a peri-urban area of a medium-sized city.
► Transition evaluation with stability grade and rate of artificialisation indicators.
► Land use systematic and casuistic processes of transition, overall gains and losses.
► Classes analysis isolate sequential steps and an increasing pattern complexity.
► Land use transitions reflect Municipal Master Plans and the land regulatory regime.