• Energy Research

Climate change is an issue of concern and is expected to cause various adverse impacts on human societies in the near and long-term future. Sea-level rise, which is caused by global warming and melting continental ice sheets, in combination with the rising global population and evolution of human activities in coastal areas, tends to make coastal societies more prone to coastal hazards. The Gulf of Corinth in Greece with its diverse coastal landforms and tectonic complexity makes the region unique when considering an assessment of coastal vulnerability. In this study we apply an Integrated Coastal Vulnerability Index (ICVI) to a potential sea-level rise for the southern coastline of the Gulf of Corinth (Greece) consisting of physical and socio-economic parameters. Among multiple different methodologies that have been developed over the recent years, we decided to apply two of the mathematical approaches we believe are best suited for the protection of human activities in our study area. The first one, ICVI_1, is based on the Coastal Vulnerability Index (CVI) by Thieler and Hammar-Klose (1999) with variables of equal relative importance, whereas the second one, ICVI_2, uses the Analytic Hierarchic Process (AHP) with the assignment of relative weight values to each parameter. The parameters were identified and ranked into a vulnerability index with a scale from 1 to 5. The results reveal that both approaches depict more or less the same coastal sections of high or very high vulnerability, but differ in the distribution of extreme values. ICVI_1 shows that 18.3% of the total coastline features very high vulnerability (score 5), while ICVI_2 shows 9.1%. The coastal sections with the highest scores of vulnerability are mostly represented in the eastern part of the studied coastline with low-lying regions of gentle slope and concentrated human activity.

This study deals with the flood-hazard assessment and mapping in the catchment of Megalo Rema (East Attica, Greece). Flood-hazard zones were identified utilizing Multi-Criteria Decision Analysis (MCDA) integrated with Geographic Information System (GIS). Five factors were considered as the most influential parameters for the water course when high storm-water runoff exceeds drainage system capacity and were taken into account. These factors include slope, elevation, distance from stream channels, geological formations in terms of their hydro-lithological behavior and land cover. To obtain the final weights for each factor, rules of the Analytic Hierarchy Process (AHP) were applied. The final flood-hazard assessment and mapping of the study area were produced through Weighted Linear Combination (WLC) procedures. The final map showed that approximately 26.3 km2, which corresponds to 22.7% of the total area of the catchment, belongs to the high flood risk zone, while approximately 25 km2, corresponding to ~15% of the catchment, is of very high flood risk. The highly and very highly prone to flooding areas are located mostly at the southern and western parts of the catchment. Furthermore, the areas on both sides of the channel along the lower reaches of the main stream are of high and very high risk. The highly and very highly prone to flooding areas are relatively low-lying, gently sloping and extensively urbanized, and host the densely populated settlements of Rafina-Pikermi, Penteli, Pallini, Peania, Spata, Glika Nera, Gerakas and Anthousa. The accuracy of the flood-hazard map was verified by correlating flood events of the last 30 years, the Hydrologic Engineering Center’s River Analysis System (HEC–RAS) simulation and quantitative geomorphological analysis with the flood-hazard level. The results of our approach provide decision makers with important information for land-use planning at a regional scale, determining safe and unsafe areas for urban development.