Crecimiento urbano (1956-2005) y sellado antropogénico del suelo en el municipio de Alacant

Zusammenfassung

In the Comunitat Valenciana, land use changes caused by urban growth have affected especially the metropolitan cities of the coastal plains. In these areas the soils often are highly productive and can support an intensive and profitable agricultural system. Most the population, infrastructures, economic activities of the region are concentrated in these urban centres. This paper analyses the spatial and temporal dynamics of the urban use during the second half of the 20th century in the municipality of Alacant, which is located in the Mediterranean metropolitan area of Alacant-Elx, Spain. Urban growth was analyzed in a GIS framework. Photo interpretation of aerial photographs dated from 1956, 1985, 1998 and 2005 was performed to establish the urban use changes at a detailed scale (1:10,000). The land use/cover classes were high-density urban use - UAD- (when built-up area was higher than 80% of the digitized unit) and low-density urban use -UBD- (built-up area lower than 80%). The difference between the two urban classes depends of more or less presence of vegetation or bare soil on the built-up matrix. Results show a very large transformation to urban use mainly since 1998. These changes are linked with the regional economical and demographical dynamics. The population of Alacant is currently 3 times higher than 50 years ago and the built-up area is 5 times higher than in 1956. Whereas in 1956 only 995 ha (4.95 % of the total area) were occupied by urban use, in 2005 this land use covered 4,977 ha (24.75 %).