The geomorphology of Greece is the result of multiphase tectonic movements of compressional and extensional nature plus exogenous processes. In this complex relief a Mediterranean-type ecosystem has been developed reflecting the prevailing climatic conditions. The frequent occurrence, especially during summer, of strong winds and high temperatures are the main reasons for extensive fires. The aim of this paper is to develop a methodology to face with this increasing danger using fuzzy set theory in a Web-GIS platform. As a case study of this work the two of the Ionian islands, Zakynthos and Kefallinia have been chosen, which are characterized by a relatively well developed vegetative cover and frequently recurring fires. It is widely accepted that the fire management is of primary importance for the environmental protection and planning.

This study is dealing with the natural environment of the coastal zone of Paros island chosen as a representative ‘sample’ of the Cyclades complex of islands and amongst the most touristic ones. More than 75% of the coastal zone consists of high and lower cliffs, whilst relatively flat (slopes <2,5%) coastal plains do not exceed the 17% of the coastline. The island receives a considerable amount of wave energy; this has its highest values (>1500 W/m) at the NE part of the island and its lowest at the SE “protected” and shallower shelf area. Touristic (sandy/pebble) beaches have been developed along those parts of the coastline characterized by Quaternary (erodible) lithology associated with moderate wave activity. Sea level rise during the Holocene has played also an important role in coastal geomorphology; for example, Paros was connected to Naxos and Antiparos islands 10.000 yr BP and to Antiparos 6000 yr BP. A further rise of sea level (some 0,5 m at the year 2100) due to climatic changes will obviously deteriorate the terrestrial part of the coastal environment and especially all the touristic beaches and related establishments along its coastline.

In this paper we are examining Salamina island from a physical-geographical anda geomorphological aspect. For the purposes of this study, we used all existed official maps, recent aerial photographs and satellite image as well as data deriving from extensive fieldwork at the study area. The results of the photo-interpretence are combined and correlated with the outcome of the primary data (physical, geological, geomorphological) that were collected through fieldwork, which took place with the use of GPS, to ensure the accuracy of the measurements. This study resulted to the creation of a geomorphological map of the study area in a GIS environment, along with several thematic maps presenting all collected data (primary and secondary). Finally, a geomorphological and environmental evolution of the study area has taken place, in order to map the genesis of the nowadays morphology.

Coastal areas are the result of a complex interaction of many factors such as rock properties, geomorphological processes and wave action. We approach these dynamic landscapes using fuzzy set theory. As input variables we use rock’s erodibility, slope gradient, (drainage density,) vegetation and land use and wave characteristics. Next we formulate fuzzy logical rules to transform input variables to output ones. The output of the system represents the coastal depositional and erosional processes. As a case study we choose the island of Corfu (Greece) which presents lithologies very vulnerable to erosion and receives very high amount of rainfalls, in relation to the rest of the Greek territory. All this procedure has been developed using a loose coupling system of a flexible GIS platform and the proper environment to process fuzzy variables.

The main purpose of this paper, is to study the geomorphological evolution of Meganisi island’s coastal zone and to detect areas vulnerable to coastal erosion.The geomorphology of the island is effected by the lithological configuration, the tectonic characteristics, the wider seismotectonic status and the sea activity of the area. The wider area is characterized by intense seismicity: strong earthquakes are very frequent (M>6) and from the seismotectonic point of view is very complex. Limestone is the main lithological formation of Meganisi coastal zone. Coastline is steep and straight with morphological slopes ranging from 0%-66%. A big part of the area (40,87%) is of high slope (>20%). A GIS was developed using data deriving from detailed inland and sea fieldwork, aerial photos, satellite images and pre existing maps. Data were analysed statistically and geographically and variousthematic maps were created such as the morphological map, map of vulnerability, etc. Data deriving from this analysis as well as from fieldwork were processed through logical rules in order to locate zones of high erosion risk. Finally, an erosion risk map was developed in order to locate those areas that are vulnerable to futureerosion and to keep attention to them.

In this paper the area of Iliki and Paralimni karstic lakes is studied throughfieldwork and GIS. The study area is situated east of the Fokida – Beotia tectonicdepression focusing on the relation of the tectonic activity to the formation of thesurrounding slopes. As a result of this study, slope formation is related to the two main tectonic phases of the wider area.

Geographical Information Systems are important tools for various scientificaspects. Especially sciences related to cartography and geographical analysis should definitely employ GIS technology. In this study we present an Internet – based GIS that our team developed under MapXtreme platform. This application gives access to numerous web-users through a server that controls both analysis and data retrieval requests. It is a practical and economical method in order to introduce GIS to educational institutions. This Web GIS may operate through a local or wide area network and, apart from educational purposes, offers a low cost information exchange solution between vast numbers of users.

We consider a large set of data comprising N=3422 data vectors, each containing observations on p=3 variables. We find for these data representative data vectors. We do it by employing the methodology of Kohonen's self-organizing maps. The found representative data vectors are called codebook vectors. In particular we analyze two collections (assemblages) of codebook vectors counting m=275 and m=120 elements. The quantity of the representation is measured by evaluating two errors: the quantization error q1 and the topological error q2. We show for our data that the magnitude of these errors depends on the way the original data werestandardized. After a thorough graphical analysis of the results we came to the conclusion that codebook vectors obtained from data standardized by range yield a little better representation as those do which were obtained from data standardized by variance. None of the representations is satisfactory from our point of view.

We compare space quantization obtained by codebook vectors yielded by Kohonen’s self-organizing maps and the neural gas methods. The average approximation error (called also the quantization error) is smaller when applying the neural gas method. The results are visualized graphically by scatterplot matrices. For the special case of 3-dimensional data the results, i.e. location of the representative codebook vectors among the original data points – are also visualized by a rotatable 3-D plot. The analysis was carried out for the Kefallinia data counting n D 3420 data vectors, each with p D 3 components. We stated that the results depend on the way of standardization of the data.

In this paper we examine methods of digital image processing, in order to extract drainage system branches and import them into a GIS layer. Moreover, we have developed special algorithms on GIS environment in order to analyse drainage system parameters. In order to get the optimum detection of the drainage system characteristics, we applied on the Landsat image and on aerial photos several filters. Using the aerial photos of the area, we created the orthophotomosaic, which came out of the ortho-rectified aerial photos. Via stereoscopic observation on the computer screen, we detected and digitized the drainage system branches. Using special algorithms, developed under the MapBasic programming language, we evaluated the drainage system and the faults directions, in order to analyse them quantitatively and geographically.