Abstract:

The description of coastal recession is a difficult asset that is characterized by high
uncertainty. This uncertainty stems from the nature of the different factors that constitute the coastal systems. Physical features such as the different geological formations, the tectonic state of the coastal area and the sea level are all factors that complicate the efforts to describe the situation. In addition, any GIS software is lacking the tools to explain or map the uncertainty factors. Therefore, it is necessary to introduce a tool that may handle the natural factors in a GIS interface. In this paper we present an algorithm that works on a GIS interface and uses grid modeling
techniques. Taking into account factors such as the geology of the areas that are examined, the drainage system, the coastal type etc., the system applies a set of user defined empirical rules, to estimate the evolution of the recession process in the affected areas. For this paper we have tested the algorithm at the island of Samos (Eastern Aegean, Greece). In the last 20 years, huge problems of coastal erosion have been observed at the northeastern part of the island near the town of Karlovassi and at the southwestern part near the Castle of Pythagorion.
The algorithm may prove to be of great assistance as a decision support tool for the municipalities in these areas, since the measures that have been taken so far are temporary and do not envision the future development of the coastline.