Abstract (EN):
Alqueva dam was projected for the gorge of Guadiana River (Portugal) and resulted in the creation of the Europe's largest artificial lake with a flooding surface of 25,000 ha. Landsat imagery can be used for detecting terrestrial land cover conditions. In this work, 18 years of Landsat data, covering the period between 1992-2009 were used. The land use/land cover rates and flooding surface estimation were based on image classification algorithms (pixel-based and object-oriented approaches). The Landsat images are all from April and were already geometrically corrected. The selection of land-use classes is based on the Corine land cover nomenclature. In the pixel-based classification three supervised classification algorithms were applied to the dataset. The pixel-based classification algorithms presents a very good performance, demonstrated by the results of the overall accuracy (>91.55%) and Kappa statistics (>0.90). In the object-oriented approach, the region growing segmentation method was applied followed by the unsupervised Mahalanobis classification algorithm. Lastly, an estimation of the flooding surface was performed and land cover/land use maps were produced. GIS techniques were also used to quantify the land/use change rates and to compute the flooding surface increase (14,000 ha in 1992 and 23,000 ha in 2009).
Language:
English
Type (Professor's evaluation):
Scientific
Contact:
amteodor@fc.up.pt
No. of pages:
12