Electrical resistivity tomography mapping of beachrocks: application to the island of Thassos (N. Greece)   总被引：1，自引：0，他引：1  

Psomiadis David  Tsourlos Panagiotis  Albanakis Konstantinos 《Environmental Earth Sciences》2009,59(1):233-240

Electrical resistivity tomography (ERT) technique is widely used in mapping subsurface electrical properties. In this study, ERT was used to map a beachrock outcrop, extended both inland, under beach sediments, and seawards, on and under seafloor sediments. Mapping of beachrock is considered important because it can help evaluate the lateral and vertical extend of the formation. Fast and reliable mapping of beachrocks may contribute in several applications like engineering and construction, coastal management, recreational reformation as well as scientific approaches like coastal evolution research, and palaeo-environmental studies. The outcome of the survey was the mapping of the formation with centimeter precision, especially towards the sea. Special processing was applied to the data in order to constrain the inversion procedure to include the known sea water layer.  相似文献   

Identifying key environmental variables structuring benthic fauna for establishing a biotic typology for Greek running waters     

Nikolaos Th. Skoulikidis  Konstantinos C. Gritzalis 《Limnologica》2009,39(1):56-66

A central aspect of the Water Framework Directive 2000/60/EC addressed to Member Countries is to proceed to type-specific ecological assessment and classification by establishing typology systems. Sixty-four permanent stream sites distributed throughout mainland Greece and islands were assessed with macroinvertebrate indicators to evaluate their ecological quality. Local and catchment scale parameters were determined and recorded to obtain an integrated assessment of the main factors affecting stream integrity and macroinvertebrate communities. Twenty-three sites were classified as reference or good status in terms of biological, chemical and hydromorphological quality with the use of various metrics. Multivariate statistical techniques were performed (MDS, BIOENV, correlation analysis and PCA) to investigate the main environmental factors structuring benthic macroinvertebrate communities and to select candidate environmental variables for establishing a biotic typology for Hellenic rivers. The results revealed relatively distinct macroinvertebrate communities within defined abiotic zones of the country. Assemblages of macroinvertebrate fauna were most strongly associated to differences in geographical position, altitude, slope, catchment area, current velocity, conductivity and water temperature. In view of the lack of sufficient data at the country level on the three last variables and after considering cause-effect relationships between large scale variables and the latter, it has been demonstrated that a number of catchment scale variables could be used as robust surrogates.  相似文献   

Experimental investigation of inertial flow processes in porous media   总被引：3，自引：0，他引：3  

Konstantinos N. Moutsopoulos  Ioannis N.E. Papaspyros  Vassilios A. Tsihrintzis   《Journal of Hydrology》2009,374(3-4):242-254

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Modeling level selection for seismic analysis of concrete‐filled steel tube/moment‐resisting frames by using fragility curves          下载免费PDF全文

Konstantinos A. Skalomenos  George D. Hatzigeorgiou  Dimitri E. Beskos 《地震工程与结构动力学》2015,44(2):199-220

The seismic behavior of plane moment‐resisting frames (MRFs) consisting of I steel beams and concrete‐filled steel tube (CFT) columns is investigated in this study. More specifically, the effect of modeling details of each individual component of CFT‐MRFs, such as the composite CFT columns, the beam‐column connections, the panel zones, and the steel I beams on their seismic behavior, is studied through comparisons against available experimental results. Then, fragility curves are constructed for three typical CFT‐MRFs, designed according to European codes, for various levels of modeling sophistication through nonlinear time‐history analyses. On the basis of these fragility curves, one can select the appropriate modeling level of sophistication that can lead to the desired seismic behavior for a given seismic intensity. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

Analysing the topology of seismicity in the Hellenic arc using complex networks     

Eleni Daskalaki  Gerassimos A. Papadopoulos  Konstantinos Spiliotis  Constantinos Siettos 《Journal of Seismology》2014,18(1):37-46

Based on the theory of complex networks, we quantify for the first time correlations between seismic events occurring in the Hellenic arc and Trench system, which is the most seismogenic structure in the European–Mediterranean region. We examine how relatively strong events with their aftershock sequences trigger phase transitions of the underlying network topology of seismic activity from random to scale-free structures. In particular, we show that the network is characterized by a highly clustered spatial structure giving rise to heterogeneous networks exhibiting enhanced small-world attributes.  相似文献   

Seismic response analysis of adjacent liquid‐storage tanks          下载免费PDF全文

Konstantinos Mykoniou  Christoph Butenweg  Britta Holtschoppen  Sven Klinkel 《地震工程与结构动力学》2016,45(11):1779-1796

A refined substructure technique in the frequency domain is developed, which permits consideration of the interaction effects among adjacent containers through the supporting deformable soil medium. The tank‐liquid systems are represented by means of mechanical models, whereas discrete springs and dashpots stand for the soil beneath the foundations. The proposed model is employed to assess the responses of adjacent circular, cylindrical tanks for harmonic and seismic excitations over wide range of tank proportions and soil conditions. The influence of the number, spatial arrangement of the containers and their distance on the overall system's behavior is addressed. The results indicate that the cross‐interaction effects can substantially alter the impulsive components of response of each individual element in a tank farm. The degree of this impact is primarily controlled by the tank proportions and the proximity of the predominant natural frequencies of the shell‐liquid‐soil systems and the input seismic motion. The group effects should be not a priori disregarded, unless the tanks are founded on shallow soil deposit overlying very stiff material or bedrock. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

Site selection for drinking-water pumping boreholes using a fuzzy spatial decision support system in the Korinthia prefecture,SE Greece     

Andreas K. Antonakos  Konstantinos S. Voudouris  Nikolaos I. Lambrakis 《Hydrogeology Journal》2014,22(8):1763-1776

The implementation of a geographic information system (GIS)/fuzzy spatial decision support system in the selection of sites for drinking-water pumping boreholes is described. Groundwater is the main source of domestic supply and irrigation in Korinthia prefecture, south-eastern Greece. Water demand has increased considerably over the last 30 years and is mainly met by groundwater abstracted via numerous wells and boreholes. The definition of the most “suitable” site for the drilling of new boreholes is a major issue in this area. A method of allocating suitable locations has been developed based on multicriteria analysis and fuzzy logic. Twelve parameters were finally involved in the model, prearranged into three categories: borehole yield, groundwater quality, and economic and technical constraints. GIS was used to create a classification map of the research area, based on the suitability of each point for the placement of new borehole fields. The coastal part of the study area is completely unsuitable, whereas high values of suitability are recorded in the south-western part. The study demonstrated that the method of multicriteria analysis in combination with fuzzy logic is a useful tool for selecting the best sites for new borehole drilling on a regional scale. The results could be used by local authorities and decision-makers for integrated groundwater resources management.  相似文献   

Using Network Analysis for Emergency Planning in Case of an Earthquake   总被引：1，自引：0，他引：1  

Konstantinos Tarabanis  & Ioannis Tsionis 《Transactions in GIS》1999,3(2):187-197

Populations in several countries including Greece face a continuous earthquake hazard. Planning to explore how the authorities will conduct their actions when such incidents occur is very important. People have to move to safe areas called refuge areas. GIS network analysis tools can help predict how many and which people these refuge areas can host depending on the location of their residence. A network allocation model is used.  相似文献   

The importance of wind forcing in fjord wave modelling     

Christakos  Konstantinos  Furevik  Birgitte R.  Aarnes  Ole Johan  Breivik  Øyvind  Tuomi  Laura  Byrkjedal  Øyvind 《Ocean Dynamics》2020,70(1):57-75

Ocean Dynamics - Accurate predictions of surface ocean waves in coastal areas are important for a number of marine activities. In complex coastlines with islands and fjords, the quality of wind...  相似文献   

Predictive model for site specific simulation of ground motions based on earthquake scenarios          下载免费PDF全文

Christos Vlachos  Konstantinos G. Papakonstantinou  George Deodatis 《地震工程与结构动力学》2018,47(1):195-218

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