Kalliopi Gaki-Papanastassiou

Potential suitability for urban planning and industry development using natural hazard maps and geological–geomorphological parameters

During the planning of an urban environment, usually only economic and social parameters are taken into account. As a result, urban areas are susceptible to natural disasters, which cause extensive damages in them, because the cities or towns have been repeatedly located in vulnerable areas. In this study, for the protection of human environment, is proposed a unique approach of urban planning and sustainable development. The study area is Trikala Prefecture (Western Thessaly, Central Greece). An integrated evaluation of the suitable areas for urban growth and light industry development is proposed by using mainly natural hazards as well as geological–geomorphological–geographical characteristics of the study area. The used parameters were correlated by using the analytical hierarchical process (AHP) method and incorporated into a geographic information system (GIS) in order to produce the corresponding suitability maps. The study area is classified in five categories of very high, high, moderate, low, and very low suitability for urban growth and industrial development. Moreover, the spatio-temporal changes of the urban limits are studied since 1885 for the three major towns (Trikala, Kalambaka and Pyli) of the study area. These changes sketch out the urban growth trend. The comparison between the urban growth trend with the potential suitability for urban growth and industrial development of these towns lead to discrepancies. These can be attributed mainly to the fact that in the majority of cases, only geographical, social, and economical factors were used for urban development, whereas in our study, natural hazards, geomorphological, and geographical parameters were quantified and taken into account.

Assessment of rural community and agricultural development using geomorphological–geological factors and GIS in the Trikala prefecture (Central Greece)

In this study, the potential land use planning for rural communities and agricultural development is examined with a multi-criteria analysis and Geographical Information System. For this purpose, geological, geomorphological and socio-economic data and natural hazard maps were chosen as major factors affecting both land uses. The Analytical Hierarchical Process method was applied to evaluate these factors and the uncertainty of their weight alterations estimated. Three scenarios were developed for each land use to examine the effect of uncertainty to the suitability assessment results, leading to the corresponding potential suitability maps. The areas of very high suitability are distributed mainly at the plain part of the study area. The proposed methodology comprises a case application concerning physical factors in conjunction with natural hazard maps in the land use planning procedure.

Scent of a myth: tectonics, geochemistry and geomythology at Delphi (Greece)

Extensive geochemical investigation (of water, travertine, soil and diffuse gas), coupled with geo-structural analysis, provides new insights into local fault–fluid interaction and allows us to pinpoint basic elements in the geological origin (or geomythology) of the Delphic Oracle, still debated by geologists. Delphi hosted the most famous oracle of antiquity, supposed to prophesy under the effects of intoxicating gas exhaling from a chasm in the ground. CO2–H2S-rich, ethylene-rich or CH4-rich gases have been invoked to explain the mantic vapours. Although previous interpretations dismissed the results achieved by classical scholars, this study fits together history, archaeology, mythology and geology in a single coherent frame. We highlight that no hydrocarbon gas discharges are released at present to the surface in the area. The lack of any geochemical ‘anomaly’ indicates that the Delphi active fault does not at present constitute a preferential route for the circulation of thermogenic deep fluids. The mythological gas-exhaling chasm can plausibly be related to episodic seismic ruptures in the ancient past, which affected for a limited time gas pockets fed by a relatively deep confined hydrothermal system. The Delphi fault has produced shocks up to Ms=6.7 (1 August 1870), and similar seismic faulting events in the past could have episodically triggered CO2–H2S-rich emissions.

Geomorphological study of Cephalonia Island, Ionian Sea, Western Greece

In this paper a geomorphological map, at a scale of 1:50,000, of the Cephalonia Island located in the Ionian Sea (western Greece) is presented and discussed. The geology of the island is represented in an individual smaller inset map. The map was produced from field surveys based upon 1:50,000 scale topographic maps and 1:5000 topographic diagrams, differential global positioning system surveys, aerial photos and visual inspection and interpretation of Google Earth images, and analysis of a digital elevation model of the island derived from 1:50,000 scale topographic maps. Landforms were grouped on the basis of the main morphogenetic processes and include fluvial landforms, erosional landforms, gravitational landforms, karst landforms, and coastal features. The objective of this map is to provide information about the landscape evolution of the island during the Quaternary. The study of the landforms depicted on the geomorphological map showed that the recent evolution of the landscape is dependent mostly on neotectonic processes and eustatism.

Geomorphology of the Pinios River delta, Central Greece

ABSTRACT This paper presents the results of geomorphological investigations carried out on the Pinios River delta, which is a Late Holocene arcuate type delta, located in the southern Thermaikos Gulf (Central Greece). Digital elevation model (DEM) analysis and the study of maps of the last two centuries, accompanied by field survey and aerial photo interpretation have led to the production of a geomorphological map at 1:15,000 scale which outlines the features of the deltaic plain and coastal zone. The evolution and the associated morphology of the delta are the result of the complex interplay of fluvial sedimentation, wave activity and prevailing longshore currents. The dominant landforms of the delta are the numerous abandoned meandering channels, as the river has changed its course several times, and a series of sub-parallel linear sandy beach ridges (cheniers) occupy the lower delta plain. The shoreline of the delta is generally retreating due to marine processes, especially where former river mouths occur whereas the presently active mouth of the river and its immediate surrounds are prograding.

Volcano Tourism in Greece: Two Case Studies of Volcanic Islands

The Greek volcanoes are part of the Aegean Volcanic Arc, which is caused by the subduction of the African tectonic plate under the Eurasian plate. Santorini is the most famous volcano in Greece, and was the site of the most recent volcanic eruption in Greece in 1950; the others are Methana, Milos, Nisyros, Yali and Kos (Table 5.1).

Investigation of flash flood natural causes of Xirolaki Torrent, Northern Greece based on GIS modeling and geomorphological analysis

This paper presents an attempt to evaluate the flood discharge for a severe flood event, which took place on October 25th, 2009. Based on spatial and meteorological data, a simulation of the flood event was established, through hydrological modeling, in a GIS environment. Furthermore, the geomorphological characteristics of the drainage basin and the drainage network were analysed. The results of the modeling such as the peak discharge, hydrograph, and volume, derived from the analysis of measured hydrographs in a number of non-flood causing rainfall events with operating stage gauge, were used for calibration and verification of the simulated stage-discharge hydrographs. Drainage basin characteristics such as steepness of the relief combined with a relatively short main channel of the drainage network as well as abnormalities in the hierarchical drainage by stream order are the main natural flood causes amplified of course by the intense human interference at the lower part of the drainage network with a series of constructions such as roads inside the main channel. Geomorphological analysis combined with GIS techniques are fundamental components of flood risk management as they provide the basis for a broad understanding of the relationship between river processes and flood causes in a fast and effective way in the context of policy makers.

Late Quaternary rates of stream incision in Northeast Peloponnese, Greece

This study focuses on defining rates of fluvial incision for the last 580±5 kyr along valley systems of eight streams that drain the eastern part of the northern Peloponnese. The streams are developed on the uplifted block of the offshore-running Xylokastro normal fault, one of the main faults bounding the southern edge of the Gulf of Corinth half-graben, and have incised a set of ten uplifted marine terraces having an amphitheatric shape. These terraces range in age from 60±5 kyr to 580±5 kyr and have been mapped in detail and correlated with late Pleistocene oxygen-isotope stages of high sea-level stands by previous studies. The terraces were used in this paper as reference surfaces in order to define fluvial incision rates at the lower reaches of the studied streams. To evaluate incision rates, thirty-three topographic valley cross-sections were drawn using fieldwork measurements as well as using a highly accurate (2×2 cell size) Digital Elevation Model (DEM) at specific locations where streams cut down the inner edges of the marine terraces. For each cross-section the ratio of valley floor width to valley height (Vf) and long-term mean stream incision rates were estimated for the last 580±5 kyr, while rock uplift rates were estimated for the last 330±5 kyr. The geomorphic evolution of the valleys on the uplifted block of the Xylokastro fault has been mainly driven by the lithology of the bedrock, sea level fluctuations during the late Quaternary, and incision of the channels due to the tectonic uplift. Stream incision rates range from 0.10±0.1 mm/yr for the last 123±7 kyr to 1.14±0.1 mm/yr for the last 310±5 kyr and are gradually greater from east to west depending on the distance from the trace of the fault. Downcutting rates are comparable with the rock uplift rates, which range from 0.4±0.02 mm/yr to 1.49±0.12 mm/yr, over the last 330±5 kyr.

The Uplifted Terraces of the Arkitsa Region, NW Evoikos Gulf, Greece: A Result of Combined Tectonic and Volcanic Processes?

The Arkitsa-Kamena Vourla area of central Greece occupies a zone of accommodation between the two tectonic provinces of the North Aegean Trough (the extension of the North Anatolian fault system) and the Gulf of Corinth and is characterized by a series of very prominent tectonic landforms, notably the large (ca. 1000 m elevation) footwall ridge of the Arkitsa-Kamena Vourla fault system. Despite the highly prominent nature of this footwall ridge and the presence of very fresh tectonic landforms, this fault system is not known to have hosted any major historical earthquakes, and the tectonic and geomorphic evolution of the Arkitsa-Kamena Vourla area remains poorly constrained. This article utilizes a combined geomorphological, sedimentological, and macro-/microfossil approach to evaluate the Late Quaternary evolution of the Arkitsa area, in the eastern part of the fault system, focusing on prominent uplifted terraces present in the hanging wall of the Arkitsa fault. Three distinct raised glaciolacustrine terraces and previously reported uplifted marginal marine deposits suggest sustained uplift of the coastline at a rate of 1–1.5 mm/yr over the past at least 40,000 yr, possibly dating to 75,000 BP. While movement on an offshore normal fault strand may explain more recent coastal uplift, purely fault-driven, longer-term uplift at this rate requires anomalously high fault-slip and extension rates. Consequently, the development of the terraces and other geomorphic indicators of uplift may be at least partly due to nonfaulting processes, such as Quaternary (intrusive and/or extrusive) volcanic activity associated with evolution of the nearby Lichades volcanic center.