In this paper we are studying the erosional procedures on the basis of Geographical InformationSystems (GIS) and Artificial Intelligence (AI) methods. More precisely we use fuzzy logic rules toestimate the erosion risk index for the surface rocks and a model of neural networks to spatially categorisethe erosion risk index. The described procedure is applied at Zakynthos island, where acomplete spatial database already exists.

The main purpose of this paper, is to study the coastal morphology of the five largest islands in the Ionian Sea (Zante, Kefallinia, Ithaki, Leukas, Corfu) located in Western Greece, in relation to lithology, tectonic characteristics, general seismotectonic regime and marine processes of the area, and finally to locate sites of possible future coastal retreat. The predominant lithological formation of the coasts of Zante, Kefallinia, Ithaki and Leukas, is the carbonate rocks. The shores of Corfu island are composed mainly of Neogene and Quaternary formations. The morphology of the steep coastline is determined in general by offshore normal faults having NW-SE and N-S directions and the relief steepness is intensified by the high resistivity of the calcareous formations. The low relief coasts are common in areas where Quaternary deposits are dominant. Data derived from aerial and satellite images, large scale maps and detailed fieldwork mapping were treated by GIS. The upper coastal zone limit was extended up to the 20m contour line. A coastal hazard map was developed focusing on erosion prone areas. The most vulnerable were found to be the western coasts of Leukas, south Kefallinia, north Ithaki and north Corfu. Landslides and rockfalls are especially risky in western Leukas, northern Corfu and southernKefallinia.

In this paper the area of the lakes Iliki and Paralimni are examined (Viotia). The research focuses on the influence of the tectonic on the morphological structure of the area and on the formation of the lakes, with fieldwork and the use of GIS (Geographic Information Systems). For this purpose the azimuth directions ofthe rupture zones were calculated with the use of ‘geoline orientation’ algorithm. The analysis of the morphological slopes and of the aspect was performed with the use of the algorithm ‘Triangulation with smoothing’. The outcome of the fault direction concurs with the Pliocene faults direction, as well as the tectonic Fokiko - Viotiko trough direction. The Quaternary faults direction concurs with the recent rupturezone. In general, the dominating morphological slopes are of 0-10%, while the higher slopes are found at the north and east. The aspect that concerns the direction of the morphological slope concurs with the main rupture zone of the tectonic Fokiko - Viotiko trough direction, and the recent rupture zone. The orientation of Iliki lake corresponds to the former rupture zone; the orientation of Paralimni lake corresponds to the later one.

The erosional processes depend on various variables such as lithology, topography,drainage system, rock structure and climatic conditions. The quantitative evaluation on some of the above geological and geomorphological parameters is of primaryimportance for the purpose of developing erosion risk maps. These maps can become useful tools for developing appropriate strategies on environmental protection, hazard assessment and regional planning. The island of Sifnos, in Cyclades, was chosen as a case study, where in the final map of the sub-basins of this island, erosion risk distribution is presented.