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Monitoring wetlands along the ‘Western-Greek Bird Migration Route’. Spatio-temporal change detection using remote sensing and GIS in Logarou Lagoon, Western Greece: a pilot study Host Publication: 6th European Conference on Ecological Restoration, 8-12 September 2008, Ghent, Begium Authors: R. Lagring, F. Mpazigou, N. Koedam and J. C-W Chan Publication Year: 2008
Abstract: The population of long-distance migratory birds is declining worldwide mainly because of loss of suitable stopover-sites. Wetlands are important stopover-sites for birds offering them energy along their journey. The geographical position of Greece makes it an important transit zone for migratory birds. Along the western coast of Greece there numerous wetlands supporting the defined in this research 'Western-Greek Migration Route'. During the 20th century, the majority of the Greek wetlands were degraded and lost by drainage and development. Further loss and/or deterioration of wetlands along the 'Western-Greek Migration Route' can result in a critical lack of suitable stopover sites for migrating birds.
In this research, a monitoring method was designed to perform a post-classification change detection in wetland area, using remote sensing and GIS, with surface area of habitat types as an indicator. A monitoring and a classification schedule were created using MedWet guidelines. Logarou lagoon was selected as a study area to perform a pilot study. The cost- and labor-effectiveness, the reliability and the feasibility of the method was of interest. Two types of imagery material were used: aerial and satellite images. Habitat maps were created for the study area based on aerial photographs of 1945 and 1985. Afterwards, the areas of each habitat type were compared. From 1945 to 1985, changes had occurred in all classes (expansion of agriculture, road building and construction of an aquaculture plant). Three Landsat images (1977, MSS 1989, TM and 2000, ETM+) were selected from 'NASA's Global Orthorectified Landsat Data Set'. Each image was classified separately using a Hybrid unsupervised-supervised method. Finally, a post-classification comparison was performed using raster GIS-based matrix analyses for the paired maps: 1977, 1989 and 1977. The results of the change detection show that Logarou lagoon is a very dynamic system, where habitats easily convert from one class into another. The most important human induced change between 1977 and 2000, was the construction of an aquaculture plant (about 420 ha) in a marsh area (about 800 ha) that probably affected the fauna and flora.
The pilot study proves that the methodology developed to monitor wetlands is cost- and labor-effective, reliable and feasible for detecting changes in wetland area. Therefore, it could be used to investigate all wetlands along the 'Western-Greek Migration Route' In a next phase, the biological relevance of these changes needs to be examined with the main question 'What changes in wetland habitats are important for migrating water birds?'
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