Les images satellites Spot multi-dates et la métrique spatiale dans l’étude du changement urbain et suburbain – Le cas de la basse vallée de la Bruche (Bas-Rhin, France)

The study of urban and peri-urban change represents a major challenge for local authorities, especially in areas at risk (ex. flood) and representing an ecological potential. The Bruche lower valley (Bas-Rhin, France) is increasingly urbanized under pressure from Strasbourg. The monitoring of the settlement process was achieved over a period of 20 years to identify the phases of urbanization and their consequences. The multi-temporal remote sensing images of Spot acquired in 1986, 1996 and 2005 and "spatial metric" were jointly used to identify the main forms of evolution of land-cover during this period and to characterize the landscape changes. The results highlight a trend of increasing density and sprawl process in the valley accompanied by a significant change of the landscape structure. The paper is structured in four sections. First, related works on monitoring of land-use/cover are exposed. Second, image processing are presented and the application of various landscape metrics. Third, the description of results is detailed. Finally, conclusion and perspective approaches are discussed.