Auteurs :
ERNOUL L., SANDOZ A. & FELLAGUE A.
Résumé :
Land cover and land cover change, both in time and space, were analyzed in the Gediz Delta (Turkey) and the Rhone Delta (Camargue, France) to determine the evolution of two great deltas in the Mediterranean basin. Geographical Information Systems and remote sensing were used to estimate the impact of land use changes on habitats over a 35 year period from 1975 to 2010. The first images used MSS captures from 1975 with a spatial resolution of 80 m; precision was gained from 1980 with the use of LandSat satellite images (spatial resolution of 30 m in multi-band modes) and then with satellite images from Spot 4, Spot 5 and Google Earth Pro. The images were classified using GEO Image and then analyzed and laid out with the aid of ArcGis and Quantum GIS 1.7.0 software programs. The data was verified using a confusion matrix, which provided between 85 and 95% global precision rates. This qualitative data on the evolution reveals that despite important conservation measures (including Ramsar site, National Park, and Natural Park status) both deltas have been subject to substantial changes over this time period. Important declines in natural habitats such as sansouires, beaches, dunes and reed beds have been replaced by increased areas of urbanization and annual agricultural crops. This analysis demonstrates the important pressures that continue to impact the delicate natural Mediterranean habitats and puts in evidence the need to enforce current legislation in order to conserve the deltas in the future.