Publications by Year: 2016

Arianoutsou M, Christopoulou A, Vassilakis E, Papanikolaou I, Farangitakis GP. Investigating the Role of Bedrock Geology on the Process of Post-Fire Vegetation Recovery: A Case Study from the Taygetos Mountain. In: 8th Panhellenic Conference of Ecology (HELECOS). Thessaloniki; 2016.Abstract
Fires of 2007 have consumed large areas of Black pine and Greek fir forests in Peloponnese, Euboea and Attica. Most studies that followed, focused on the natural regeneration potential or the need for reforestation. The current research aims at examining the role of geomorphology and lithology that govern the soil properties upon the post-fire vegetation recovery at the landscape level. A case study from Taygetos Mt, a large part of which was burned in 2007, is presented. Based on the interpretation of a high spatial and spectral resolution satellite image (WorldView-3, 4/2015), several GIS thematic layers have been created showing unburned and regenerated patches over various lithological types. A network of sites was selected for field sampling representing various combinations of the above. Data on vegetation cover and recovery of the main tree species were collected. Results prove the interrelationship between regeneration and species traits as well as the existence of unburned patches near the burned ones. Recovery seems to be controlled by the geology of the plots as it was found weaker in plots overlying carbonate, permeable, not easily erodible formations as compared to that observed over clastic, impermeable, erodible formations of schists, even for the same species. In conclusion, post-fire vegetation recovery at the landscape level seems to be a complex process controlled not only from species biology but also from the landscape features and its fire history.
Vallatou Μ, Mitsopoulos Ι, Mallinis G, Vassilakis Ε, Arianoutsou Μ. Modeling Spatial Fire Risk and Exposure to Important Habitats in Cephalonia Island. In: 8th Panhellenic Conference of Ecology (HELECOS). Thessaloniki; 2016.Abstract
Within this study we introducea framework for assessing spatial fire risk and exposure to three important habitat types in Cephalonia island, Greece.Existing maps were used for plot allocation in orderto measure several fuel parameters in representative natural fuel complexes for site-specific fuel models development, as well as for collecting training and validation points for satellite data classification. The spatial extent of the fuel types and the canopy cover were delineated using a Landsat 8 OLI image acquired on 23-7-2015and the Support Vector Machines-(SVMs) machine learning algorithm. Subsequently, The Minimum Travel Time (MTT) algorithm, as it is embedded in FlamMap spatial fire simulation software, was applied in order to assess critical fire behavior parameters and exposure of Cephalonia's habitats under three different meteorological and fuel moisture scenarios. The outputs of this study may be used as an application of quantitative and probabilistic risk assessment for habitats conservation planning, prioritization and management of high value natural and cultural resources.
Lekkas E, Filis C, Andreadakis E, Skourtsos E, Diakakis M, Mavroulis S, Papaspyropoulos K, Alexoudi V, Kommatas M, Karalemas N, et al. Post-Fire Hazard and Risk Assessment in Fire-Affected Areas with GIS and Satellite Imagery: The Case of 2015 Laconia Forest Fire (Southeastern Peloponnese, Greece). In: Safe Greece - Safe Evros 2016. Alexandroupoli; 2016. pdfAbstract
On July 17, 2015 a forest fire that broke out in the southern part of Epidavros Limira peninsula (Laconia, southeastern Peloponnese), expanded rapidly due to strong winds blowing in the area and raged out of control for two days, inducing substantial damage to agriculture, livestock farming, buildings and infrastructure and causing one fatality. Innovative GIS-based methods were developed and implemented for the first time in a fire-affected area in Greece for mapping the post-fire erosion, flood and landslide hazards and risks. Geomorphological, geological, tectonic, hydrological, meteorological and land-use data along with a WorldView-2 satellite image and post-fire field observations were evaluated and used. A newly developed method was applied for assessing the erosion hazard. Analytic Hierarchy Process and Weighted Linear Combination methods were used for assessing the post-fire landslide susceptibility. The HEC-RAS model was used for hydraulic simulation and assessment of flood risk under post-fire conditions. Post-fire erosion, flood and landslide hazard and risk maps were constructed for the affected area delineating locations with very low, low, moderate, high or very high hazard and risk of erosion, flood and landslide respectively. The developed methodology is a useful post-fire hazard and risk assessment tool and can be applied by state authorities to assess the geo-environmental impact of fire disasters in areas with similar environmental conditions.
Malandri C, Soukis K, Maffione M, Özkaptan M, Vassilakis E, Lozios S, van Hinsbergen D. Vertical axis rotations accommodated along the ‘Mid-Cycladic Lineament’ on Paros Island in the extensional heart of the Aegean orocline (Greece). Lithosphere [Internet]. 2016;L575.1(doi:10.1130). pdfAbstract
The Aegean-west Anatolian orocline formed due to mainly post-15 Ma opposite rotations of its western and eastern limbs, which contributed to the opening of the Aegean back-arc basin. Stretching lineations in exhumed metamorphic complexes in this back-arc basin mimic the regional vertical axis rotation patterns and suggests that the oppositely rotating domains are bounded by the ‘Mid-Cycladic Lineament’, the tectonic nature of which is enigmatic. Some authors have proposed this lineament to be extensional fault accommodating orogen-parallel extension, while others considered it a transform fault. The island of Paros hosts the only exposure of the Mid-Cycladic Lineament: the northwest of the island contains E-trending and the southeast contains N trending stretching lineations. Here, we show new paleomagnetic results from isotropic, ~16 Ma granitoids that intruded both domains. These demonstrate that the trend difference resulted from post-16 Ma ~90° clockwise and 10° counterclockwise rotation of the northwest and southeast blocks, respectively. We show that a greenschist facies, semi-ductile to brittle, low-angle, southeast dipping normal fault zone, here identified as the Elitas Shear Zone that we interpret as the Mid-Cycladic Lineament accommodates this rotation difference on Paros. We conclude a two-stage exhumation history for Paros that is consistent with regional Aegean reconstructions. Between ~23 and 16 Ma, the metamorphic rocks of Paros exhumed from amphibolite-facies to greenschist facies conditions along a top-to-the-north detachment. The Elitas shear zone then started to exhume the northwestern clockwise rotating domain from below the southeastern, counterclockwise rotating domain since 16 Ma. We demonstrate at the only location at which a structure coinciding with Mid-Cycladic Lineament is exposed, it is extensional in nature, consistent with geometrical predictions that Aegean oroclinal bending must have been accommodated by combined orogen-normal and orogen-parallel extension.
Vassilakis E, Tsokos Α, Kotsi Ε. Shoreline change detection and coastal erosion monitoring using digital processing of a time series of high spatial resolution remote sensing data. 14th Intern. Conf. of the Geological Society of Greece [Internet]. 2016. pdfAbstract
The long term change of the shoreline is a phenomenon, which is factored in the design of construction projects along the coastal zone. This study presents a meth-odology that aims to quantify the shoreline displacement rate. The described meth-odology involves the interpretation of different remote sensing data types, which make up a quite dense time series of representations for the coastline spanning from 1987 to 2012. The representation of the shoreline is based on geometrically corrected (ortho-rectified), historical, analogue, panchromatic, high resolution aerial photos of the area (1987, 1996) and latest generation, digital, multispectral, high resolution satellite images (2000, 2008, 2012). In all cases the images were digitally processed and optically optimized in order to produce a highly accurate representation of the shoreline in each time period. All the data were imported in a Geographic Information System platform, where they were subjected to comparison and geo-statistical analysis. A large number of sections perpendicular to the coast (every 100 meters) was drawn and the relative motion of the coastline was calcu-lated for each of them. The average rate of the calculated erosion is in the order of 24mm/year whilst extreme rates of 1m/year were also observed in specific posi-tions.
Hloupis G, Leoussis C, Pagounis V, Tsakiri M, Vassilakis E, Zacharis V. Development of a Wireless Sensor Network System as basis for Early Warning in Slope Monitoring of the Corinth Canal. In: 3rd Joint International Symposium on Deformation Monitoring (JISDM). Vienna; 2016. pdfAbstract
Corinth Canal is an important technical construction with a significant role in marine and land transportation for Greece. Whilst the main highway of the Corinth bridge is well monitored there is no similar monitoring scheme for landslide failures of the canal walls. This work presents an in-house developed real-time early warning landslide triggering system using wireless sensor network (WSN) nodes. Specifically, for the detection of different types of landslide processes (drift, slide and fall) a set of corresponding MEMS (Micro-Electro-Mechanical Systems) sensors (accelerometer, inclinometer, magnetometer) will be used. These sensors along with radio transmission unit and microprocessor comprise a WSN node. The option for in-situ processing (i.e transmitting only alerts) is possible in order to decrease the communication costs. In conjunction with the proposed WSN system, high accuracy geodetic techniques are used with terrestrial laser scanning (TLS) measurements. TLS is augmenting the point-based system to a spatial -based monitoring system. The paper describes the use of WSN node as triggering device in order to alert the users to begin TLS measurements. A description of the network topology is given along with the implementation of the system in selected control points on the canal walls. Real results are shown and the performance of the system is discussed.