This study aimed to investigate the statistical correlation between the static and dynamic Young's modulus of prasinites, a metabasic rock type that outcrops at various localities in the southern part of the Attica peninsula. A total of 39 cylindrical specimens was prepared and an extensive experimental program was carried out to determine the static and dynamic deformational properties for each specimen. Using ordinary least squares regression techniques, a new empirical linear equation was established between the aforementioned properties that can be used in the study region, or elsewhere where metabasic rocks with similar characteristics are investigated.

The objective of this study is the determination of the various stages of deformation of brecciated marbles, under uniaxial compression, and the application of regression techniques, to investigate the relations of these stages, with physical, dynamical, and mechanical properties. Therefore, a total number of fifteen specimens, prepared from samples obtained from various locations from the southern part of the East Attica Prefecture, Greece. The laboratory program involved the determination of the uniaxial compressive strength (UCS), the crack initiation (Cci) and crack damage stress (Ccd) levels, the static elastic modulus (Es), as well as the basic physical and dynamical properties, such as the dry density (γd), the effective porosity (neff) and the ultrasonic velocities of both primary (VP) and secondary (VS) waves. Results obtained from the mechanical tests reveal that the onset of stable (Cci) and unstable (Ccd) crack growth varies between 0.19–0.38 and 0.66–0.92 of the UCS values, respectively. Applying simple nonlinear regression models, it was found that crack initiation and crack damage stresses, decrease exponentially with the increase of effective porosity, while increase exponentially with the increase of static elastic modulus, dynamic elastic modulus (Ed), and the primary wave velocity.

The purpose of this study is to present a Bayesian approach (weight-of-evidence method) that utilizes GIS and employs statistical analysis in defining the main factors contributing to the occurrence of landslides in Kimi, Euboea, Greece and to calculate the probability for future landslide manifestation. Landslide locations were identified from field surveys and interpretation of aerial photographs. Additional data were collected from various sources (topographic, geological, land cover maps etc.) and introduced into a spatial database using GIS technology. The above data sources have been used to generate various thematic data layers that have been resample to 20x20 m grid size. Applying the developed methodology it was possible to generate appropriate susceptibility map and thus to predict areas of instability. The results of the analysis were verified using the landslide location data, showing a satisfactory agreement between expected and existing data on landslide location. The outcomes could be used to reduce associated hazards, and to plan land use construction.

The geological, geomorphic conditions of a mountainous environment along with precipitation and human activities influence landslide occurrences. In many cases, their relation to landslide events is not well defined. The scope of the present study is to identify the influence of physical and anthropogenic factors in landslide activity. The study area is a mountainous part of the northern Peloponnesus in southern Greece. The existing landslides, lithology, slope angle, rainfall, two types of road network (highway-provincial roads and rural roads) along with land use of the study area are taken into consideration. Each physical and anthropogenic factor is further divided into sub-categories. Statistical analysis of landslide frequency and density, as well as frequency and density ratios, are applied and combined with a geographic information system (GIS) to evaluate the collected data and determine the relationship between physical and anthropogenic factors and landslide activity. The results prove that Plio-Pleistocene fine-grained sediments and flysch, relatively steep slopes (15°–30°) and a rise in the amount of rainfall increase landslide frequency and density. Additionally, Plio-Pleistocene fine-grained sediments and flysch, as well as schist chert formations, moderate (5°–15°) and relatively steep slopes (15°–30°), along with the amount of rainfall of >700 mm are strongly associated with landslide occurrences. The frequency and magnitude of landslides increase in close proximity to roads. Their maximum values are observed within the 50 m buffer zone. This corresponds to a 100 m wide zone along with any type of road corridors, increasing landslide occurrences. In addition, a buffer zone of 75 m or 150 m wide zone along highway and provincial roads, as well as a buffer zone of 100 m or 200 m wide zones along rural roads, are strongly correlated with landslide events. The extensive cultivated land of the study area is strongly related to landslide activity. By contrast, urban areas are poorly related to landslides, because most of them are located in the northern coastal part of the study area where landslides are limited. The results provide information on physical and anthropogenic factors characterizing landslide events in the study area. The applied methodology rapidly estimates areas prone to landslides and it may be utilized for landslide hazard assessment mapping as well as for new and existing land use planning projects.

This paper presents the statistical processing of data obtained from multistage triaxial tests of selected rock types from East Attica Prefecture of Greece. Two strength models for the peak and residual strength were fitted to the experimental data, i.e., the Mohr - Coulomb criterion and the Hoek - Brown criterion. The derived strength parameters for these distinct states of stress are compared with findings of other researchers and their dramatic change during the residual state of the rock samples is discussed.

This paper presents an application of the rock engineering system (RES) in an attempt to assess the proper landslide parameters and estimate the instability index, using two disastrous landslides in Greece which took place in Panagopoula (1971) and Malakasa (1995). RES has been developed by Hudson (Rock engineering systems: theory and practice. Ellis Horwood Limited, 1992 ) to determine interaction of a number of parameters in rock engineering design and calculate instability index for rock slopes. In this paper, an attempt is made to prove, how RES can be implemented in large-scale instability areas where natural slopes are associated with a variety of geomaterials (soils, rocks, weathering mantle, etc.), by selecting each time the most appropriate parameters that are relevant to the ad hoc potential slope failure and which can be quantified easiest than those of time and money consuming ones. RES approach allows the utilization of those parameters which are particularly active at the site, evaluates the importance of their interactions, taking into account the particular problems at any investigated site. The instability index for both study areas were calculated and found 89.47 for Panagopoula site and 81.59 for Malakasa (out of 100). According to the classification for landslide susceptibility by Brabb et al. (Landslide susceptibility in San Mateo County, California, 1972 ), both the examined case studies are classified as landslides, approving their existence as two serious slope failures. Thus, RES could be a simple and efficient tool in calculating the instability index and consequently in getting the prognosis of a potential slope failure in landslide susceptible areas, for land use and development planning processes.

The fine grained Plio-Pleistocene sediments encountered along the Patras Ring Road project (PRR) were distinguished into two lithological units, the Upper Geotechnical and the Lower Geotechnical Unit, based on the detailed engineering geological – geotechnical mapping, at a scale of 1:5000, on fieldwork, as well as on data gained from the boreholes drilled during the design and construction of the project. These units are distinguishable, stratigraphically successive and present basic differences in lithological composition, consistency and permeability and therefore different mechanical behaviour during construction.

The aim of this study is to investigate the statistical correlations between the point load strength index and certain physical properties, e.g. the dry density and the dry longitudinal ultrasonic wave velocity of prasinites (metabasites). Statistically significant correlations established between the physical properties as well as between each physical quantity and the point load strength index. According to bibliography, this is one of the first efforts to develop relations between physical and mechanical properties for this particular petrological type, and therefore the derived equations can be a useful tool to the investigation of these petrological types, either in the study area or in other sites, where prasinites of similar structural characteristics, are examined for the foundation of various constructions.

Land subsidence induced by the overexploitation of the aquifers in Kalochori village has been occurring since 1965. The excessive water pumping led to the development of surface subsidence reaching, in several areas, the maximum values of 3 to 4m. The evaluation of the geological, geotechnical and hydrogeological setting of the wider Kalochori region as well as the historical background of the subsidence phenomena provided variable data, which were finally used for the study of the phenomenon by means of a finite element method simulation. The availability of the various geodetic records allowed the cross-checking of the results and the conduction of all necessary back analyses. Also, the knowledge of the land use distribution and the activities taking place in the wider Kalochori region helped the rational interpretation of the phenomenon and the detection of its causal factors.

Over the last two decades, many studies of landslide susceptibility assessment have been made. It is believed that the accuracy of landslide susceptibility mapping increases when all determining parameters are included in the analytical process. Rock Engineering System (RES), which is a semi-quantitative rock engineering approach and the basic tool for representing the parameters and their interaction mechanisms, can thus be useful in decision making regarding land use and development planning processes in landslide susceptible areas by providing a The purpose of this study is to prepare a susceptibility map in a landslide-prone area in Greece using Rock Engineering System (RES) and a geoprocessing tool called Model Builder. The implementation of RES is achieved through an interaction matrix, where ten parameters were selected as controlling factors for the landslide occurence. The validation of the developed model was achieved by using field-verified data, showing excellent correlation between the expected and existing landslide susceptibility level. In conjunction with Model Builder, which can overlay different layers and produce landslide susceptibility maps, RES can act as a tool for calculating the instability index and getting a prognosis of a potential slope failure in relation to sustainable development planning processes in landslide susceptible areas. L'objet de cette étude est la réalisation d'une carte de prédisposition au risque, dans un secteur sujet aux éboulements, en Grèce, en utilisant le système RES (Rock Engineering System) et un outil de traitement géologique nommé Model Builder. La mise en œuvre du RES est réalisée grâce à une matrice interactive avec sélection de dix paramètres en tant qu'éléments de contrôle d'une occurrence d'éboulement. La création de ce modèle a été validée en utilisant des données de vérification terrain qui ont montré une excellente corrélation entre les niveaux de prédisposition aux éboulements, attendus et constatés. En conjonction avec le Model Builder qui peut concerner différentes couches de terrain et produire autant de cartes de prédisposition aux éboulements, RES peut agir comme un outil de calcul de l'indice d'instabilité et de pronostic de rupture potentielle de pente en relation avec les processus de planification de développement durable dans les secteurs propices aux éboulements. El propósito de este estudio es preparar un mapa de susceptibilidad en un área propensa a deslizamientos en Grecia utilizando Rock Engineering System (RES) y una herramienta de geoprocesado llamada Model Builder. La implementación de RES se logra a través de una matriz de interacción, donde se seleccionaron diez parámetros como factores de control para la probabilidad de deslizamiento. La validación del modelo desarrollado se logró mediante el uso de datos verificados en el campo, que muestran una excelente correlación entre el nivel de susceptibilidad al deslizamiento esperado y existente. En conjunto con Model Builder, se pueden superponer diferentes capas y producir mapas de susceptibilidad a deslizamientos, RES puede actuar como una herramienta para calcular el índice de inestabilidad y obtener un pronóstico de un posible derrumbe de taludes en relación con procesos de planificación sostenibles en áreas susceptibles a deslizamientos.

The purpose of this study is to present a Bayesian approach (weight-of-evidence method) that utilizes GIS and employs statistical analysis in defining the main factors contributing to the occurrence of landslides in Kimi, Euboea, Greece and to calculate the probability for future landslide manifestation. Landslide locations were identified from field surveys and interpretation of aerial photographs. Additional data were collected from various sources (topographic, geological, land cover maps etc.) and introduced into a spatial database using GIS technology. The above data sources have been used to generate various thematic data layers that have been resample to 20x20 m2 grid size. Applying the developed methodology it was possible to generate appropriate susceptibility map and thus to predict areas of instability. The results of the analysis were verified using the landslide location data, showing a satisfactory agreement between expected and existing data on landslide location. The outcomes could be used to reduce associated hazards, and to plan land use construction.

Land subsidence manifestation due to ground-water overexploitation in the Stavros – Farsala site (eastern part of Western Thessaly Basin) has been noticed since 1990. Because of this overexploitation, an excessive drawdown of the ground water level (20 to 40m) was noticed in the various successive aquifers the last decades. The subsidence phenomena resulted to the formation of tensile surface ruptures, which occurred since 2002, affecting roads and buildings. The geological environment of the study area consists of terrestrial Pleistocene deposits containing sands and gravels interbedded with clayey silt to silty clay horizons. These alternations of aquifers (permeable coarse-grained deposits) with aquitards (impermeable to low permeability strata) create a number of successive semi-confined to confined aquifer, initially artesian. This study examines the geological and the hydrogeological conditions of the wider study area, aiming to clarify their relationship with subsidence phenomena and to provide solutions for their suspension. Note that those phenomena are expected to be more incensed during the next few years.

The need to provide data management capabilities in geotechnical projects, makes data visualization in a more understanding way vital, while improvements in computer science, have created an opportunity to rethink the manner in which such data is archived and presented. Geographic Information Systems are considered nowadays as principal methods for analysis, utilizing their ability of manipulating, compiling and processing spatial data, such as geotechnical one. In this paper, the development of Borehole Analysis System (BAS) a specific Graphical User Interface (GUI) application is proposed to access geotechnical data with the aim of a relational database and an open source GIS platform, embodied in the application. The BAS, is able to integrate multiple layers of gathered information and to derive additional knowledge by applying statistical and data mining algorithms with the use of spatial query tools. These can give reasonable conclusions and better representation in 2-D and 3-D environment. The presented application is illustrated with an example from field practice, testifying its ability to be a useful tool for management and presentation of geological and geotechnical borehole data.

The morphological and geological setting of Greece, the active tectonics and the irrational human activities results to the fact that several natural sightseeing areas or even more, archaeological sites and monuments are located in areas with unfavourable geotechnical conditions. The selection of the proper support and protection measures in most of the cases appear to be very difficult because the applied measures must reassure the minimum aesthetic destruction of the sites. The natural sightseeing area of the Arvanitia walkway, in Nafplio city, is a typical example of site, with extensive human activities, manifesting serious rockfall stability problems. The applied stability analysis pointed out the geotechnical problems and allowed the suggestion of measures for the improvement of the geotechnical behaviour of the rock mass. The measures were planned with respect to the natural beauty and the historical character of the site. Further more, the stability problems located at the slopes of the Kastoria lake walkway are briefly presented. The differences between the two sites revealed the geotechnical problems arising when the landplaning engineers do not take under consideration the engineering geological conditions during the construction of infrastructures.

This paper presents an application of the Rock Engineering system (RES) in an attempt to assess the inherent instability potential of Tsakona landslide in the region of SW Arcadia, Peloponnese, Greece which happened on February 2003. The RESystem has been considered to fulfill the basic requirements to deal with landslide phenomena, as it combines objectivity and efficiency. The main scope of RES application to landslide studying is to define the important causative and triggering factors responsible for the slope failures, quantify their interactions, obtain their weighted coefficients and calculate the instability index, which refers to the potential instability of the examined natural slope. In this study, the final implementation of the RES method is achieved through an interaction matrix, where ten principal parameters were selected as controlling factors for the landslide occurrence. It is concluded that RES could be a simple and efficient tool in calculating the instability index and as a consequence getting a prognosis of a potential slope failure regarding the land use and development planning processes in landslide susceptible areas.

In August 2007, a wildfire affected an area of approximately 135.000m 2 in the Municipality of Zacharo, located in Southern Greece at the Peloponnesus peninsula, causing the loss of 41 human lives, and having a dramatic impact on both ecology and economic-social welfare. The present study applies a simplified model for the evaluation of soil erosion and the susceptibility to landslide manifestation on the hydrological basins of the Zacharo Municipality, as consequence of wildfire. The methodology was based on the evaluation and analysis of territorial parameters such as lithology, geomorphology, hydrography and land cover, which are thought to be directly or indirectly related to soil erosion. The final product was a series of hazardous maps showing pre and post-fire soil erosion. An almost double increase in the post-fire area of high vulnerability was identified, covering 48% of the total area, and affecting dramatically the nearby communities. The outcome of this study helped the local and prefectural authorities to address certain mitigating measures in order to face the disastrous consequences of post-fire soil erosion.

SWOT (Strengths, Weaknesses, Opportunities and Threats) analysis is a useful tool for sustainable development and decision making about environmental planning and water resources management. This analysis was applied in order to evaluate the water resources of the wider area of Sperchios River. Sperchios River basin, with an average altitude of approximately 810m, covers an area of 2116 km2. The river is recharged by many streams of permanent and periodic flow and discharges in Maliakos Gulf. The steep slopes, which are present within approximately 2/3 of the total length of the river course, form a rather mountainous topography (streamy, with crucial flooding peaks and very intense sediment yield). Only in the last downstream part of Sperchios course, the topography gradually changes into a lowland relief, with an extent at the river mouth of 1830 km2. At this part of Sperchios severe cases of flooding have been occasionally observed and reported. Regarding the SWOT applications on the wider area of Sperchios River, various data were processed (geological, meteorological, hydrological, hydrogeological, land use, socio-economic and environmental parameters) in order to suggest a water management planning in the area.

One of the most important natural processes, with significant environmental impacts, is soil erosion.The aim of this paper is to evaluate and assess the erosion vulnerability of the geological formations constituting Sperchios River basin, in Eastern Central Greece, as well as to distinguish and locate the areas of such risk and estimate it.The developed methodology in this paper is based on Multi-Criteria Evaluation (MCE), with the implementation of Weighted Cartographic Overlay (WCO) technique in Geographic Information Systems (GIS) environment.By applying this method, an attempt was made to combine a set of factors, such as geological-hydrogeological characteristics, morphological slopes and hydrographic texture (causative factors of the phenomenon) along with rainfall (triggering factor) and land cover/use (competitive factor).The weighted combination of these factors defines the vulnerability of the formations in the area of interest.The main results of the methodology are two thematic maps of erosion vulnerability of Sperchios basin's formations, one that does not include land use/cover factor and one with current existing conditions of the basin (co-evaluating land use/cover).In the first case, 36% of the basin surface undergoes high erosion vulnerability, while 53% present medium vulnerability.These percentages reduced significantly in the second case (3% is the high erosion vulnerability category and 38% the medium one), fact that proves the importance of vegetation in erosion restriction and protection of the geological formations consisting the Sperchios River basin.

Landslides are one of the most frequent and disastrous natural hazards worldwide. Thus, the need of landslide susceptibility maps is of primary importance as they are both a useful tool for the land use planning and a necessary step for future development activities. This paper presents an integrated technique of analytical hierarchical process (AHP) and geographic information system (GIS) to create a landslide susceptibility map of the NE part of Achaia prefecture. The study area mainly consists of Neogene deposits and it is a part of the Corinthian graben, which characterized by intense neotectonic activity. Therefore, it is affected by many slope movements that usually cause serious damages in inhabitant areas and road networks. Based on field survey data analysis six parameters were chosen as major parameters that influence the stability of slopes to the direction of landslide manifestation. The AHP method identifies both the rate of the individual classes, and the weight of each factor. Spatial layers with their corresponding rates and weights were linearly combined to prepare the landslide susceptibility map, which includes four zones of slope movement’s susceptibility, namely a low, a moderate a high and a very high zone. The evaluation and final confirmation of the map was based on a great number of recorded landslides in the area.

The main objective of this paper is to classify landforms in Kimi municipality area of Euboea Island, Greece using advanced spatial techniques. Landform categories were determined by conducting morphometric analysis through the use of advanced GIS functions. In particular, the process of classifying the landscape into landform categories was based on Topographic Position Index (TPI). The main topographic elements such as slope inclination, aspect, slope shape (curvature), topographic wetness index and stream power index were obtained from the DEM file of the study area. Landform classification was obtained using TPI grids and the classes were related with the geological pattern and the land cover by sophisticated spatial analysis function. The knowledge obtained from the present study could be useful in identifying areas prone to land degradation and instability problems in which landforms are identified as an essential parameter