Nikolaos Depountis

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• Doctor of Philosophy
• Professor (Associate) at University of Patras

Climate change and extreme events such as droughts, heavy rainfall and flooding can influence the water column stratification in reservoir dams, decrease storage capacity, increase sediment and pollutant loads and, as a result, affect water quality. The seasonal variation in the water column stratification of reservoirs is an important parameter fo...

The integration of new technologies across scientific disciplines, including rock slope engineering, is increasingly essential. The use of drones and advanced software tools for mapping and analyzing large rocky slopes in detail has become indispensable and highly beneficial. In this context, this paper examines the process and key parameters invol...

Slope failures in overconsolidated hard clays present significant geotechnical challenges, particularly in stratified formations prone to pre-existing discontinuities. Despite extensive research on residual shear strength and fissuring in stiff clays, the role of undetected tension cracks and their interaction with hydrogeological conditions in tem...

This study aims to construct a coastal vulnerability assessment conceptual framework to improve the outcomes of Coastal Vulnerability Index (CVI) for local scale areas. Consequently, a new CVI was created adapted to the specific conditions of the area using seven variables. The new index was named Geotechnical Coastal Vulnerability Index (GCVI) due...

On the outskirts of the Pinios dam reservoir (Ilia Regional Unit, Greece), a water treatment plant serves the water supply needs of the surrounding municipalities, in which high concentrations of Fe and Mn, before treatment, have been observed. The main purpose of this research was to investigate the mechanism of increased iron (Fe) and manganese (...

The current study presents the results of a landslide susceptibility model applied in the Region of Epirus, Greece. For this purpose, a detailed record of 286 active landslides was created and the assessment of landslide susceptibility was based on the analysis of four predisposing factors (geology, slope angle, elevation, land use) and the applica...

In the outskirts of the Pinios dam reservoir (Ilia Regional Unit, Greece) a freshwater refinery serves the water supply needs of the surrounding Municipalities, in which high concentrations of Fe and Mn, before treatment, have been observed. The main purpose of this research is to investigate the mechanism of increased iron (Fe) and manganese (Mn)...

Sediment grain size and its spatial distribution is a very important aspect for many applications and processes that occur in the coastal zone. One of these is coastal erosion which is strongly dependent on sediment distribution and transportation. To highlight this fact, surficial coastal sediments were collected from a densely populated coastal z...

The primary objective of this research is to demonstrate advanced surveying methods and techniques for coastal erosion identification and monitoring in a densely human-populated coastline, the southern coastline of the Gulf of Patras (Greece), which diachronically suffers erosion problems expected to become worse in the forthcoming years due to cli...

Rockfall analysis is a multiparametric procedure with many uncertainties and the outputs are largely dependent on some critical engineering geological parameters involved in the used simulation model. In this paper, three completely different limestone rock sequences, named Pantokratoras, Vigla, and Paxos limestones along the western coastal slopes...

The Special Issue "New Perspectives for the Monitoring and Early Detection of Geohazards" published in the Land Journal is a collection of research articles, case studies, and reviews associated with recent developments on the monitoring and early detection of geohazards, and is now open for manuscript submission using the following link: https://w...

Greece is a country particularly covered by limestone formations that offer natural beauty due to the karstic phenomena. However, depending on the slopes' geological and geometrical characteristics they could pose in danger to infrastructures and human activities. In the framework of this study, the three prevailing limestone rock masses (Pantokrat...

This research aims to investigate the rockfall kinetics and particularly the individual parameters affecting rockfall's kinetic energy, with a more meticulous analysis of the restitution coefficients (vertical R N and tangential R T). For this purpose, a mathematical model was developed using Matlab software, based on the kinematic analysis of rock...

This study focuses on the role of topography in soil erosion modelling by examining the impact of topographic data from various sources on the calculation of the slope length and slope steepness factor (LS). For this purpose, the Pinios dam drainage basin in the Ilia Regional Unit, Western Greece, was selected as a pilot area of this study. Specifi...

Many significant landslide movements are often observed in the upper weathering zone of flysch, which constitutes the most critical landslide-prone geological formation in Western Greece. In this article, a laboratory approach is adopted to investigate the behavior of highly weathered and tectonically decomposed flysch for slope stability analyses...

Many mountainous villages have been struck by landslides in Western Greece due to growing urbanization and uncontrolled land use in landslide prone areas, without considering the engineering geological environment. The presence of the tectonically highly sheared and weathered geological formations of the alpine basement (such as flysch) and the int...

A new methodology for shallow landslide forecasting in wildfire burned areas is proposed by estimating the annual probability of rainfall threshold exceedance. For this purpose, extensive geological fieldwork was carried out in 122 landslides, which have been periodically activated in Western Greece, after the devastating wildfires that occurred in...

This research aims to calculate the potential of soil liquefaction due to earthquakes in the coastal area of the gulf of Patras in Greece. For this purpose, the coastal area of the gulf of Patras and its sub-regions, where liquefaction had occurred after an earthquake of Mw = 6.4 that struck Greece in 2008, has been selected as the study area. Liqu...

The current work describes a laboratory method for classifying soils according to their contamination susceptibility by using the permeameter apparatus. This methodology is applied in a laboratory environment by performing several tests on saturated soil samples derived from several sites located in the surrounding area of the city of Patras in Gre...

The aim of this specific study is to present a new weighted Coastal Vulnerability Index (CVIWF), with an emphasis given to the geotechnical evaluation and shoreline evolution rate measured through high-resolution remote sensing, which seem to be the most interfering variables in CVI calculations. As a pilot area for the application of the new CVIWF...

This textbook introduces geology for civil engineering students. It covers aspects like the planet Earth, minerals and rocks, and structures of rocks. Special attention is given to the active faults and elements of seismology. The book contains elementary data of landscapes in topographic and geological maps. It then looks at special attention to t...

In this work a complete permanent system of timely landslide warning and monitoring in Greece is presented. This system is the first that is designed for a densely residential and mountainous environment. Since 1960’s several instability phenomena have been recorded in one of the most traditional settlements in Greece, Metsovo, Region of Epirus. Th...

In recent decades, wildfires have become a serious threat worldwide, producing disasters in the natural and anthropogenic environment as well as serious economic losses. One of wildfire’s major impacts is soil erosion, as it may cause major problems in both the physical and anthropogenic environment and seriously affect the landscape. This study in...

It is well known that in order to study the shoreline evolution in an accurate way, successive time series of high-resolution images are needed. However, the availability of historical high-resolution data is limited to analogue air photos while the more recent high-resolution satellite images are quite expensive. Thus, many researchers have based...

Three of the most well-known historical landslide areas in Western Greece were examined, concerning their temporal and kinematic evolution. Long-term ground displacements based on inclinometer data were analyzed. The aim of this study is to estimate the velocity trend type of movement through the years. The total time frame of kinematic evolution r...

This research focuses on accessing the suitability of specific igneous rocks for their potential use as aggregates in road pavement layers. During the current research, several quality control tests were carried out on andesite and dacite rocks, obtained from the areas of Methana and Agioi Theodoroi, approximately 60 Km West of Athens, Greece. The...

Η συμπεριφορά του έντονα αποδομημένου και αποσαθρωμένου φλύσχη διερευνάται μέσω εργαστηριακής προσέγγισης στη συσκευή διάτμησης μεγάλων διαστάσεων σε εδαφικά δείγματα, προερχόμενα είτε από δειγματοληπτικές γεωτρήσεις, είτε από επιφανειακές εμφανίσεις του φλύσχη σε χαρακτηριστικές περιοχές-ζώνες εκτεταμένων κατολισθήσεων. Οι συνθήκες εκτέλεσης των δ...

In Western Greece, rockfalls occur every year in residential areas and on public roads, causing considerable societal and economic damage. As a result, rockfall hazard assessment is a necessity and can be a very important tool for scientists, planners, decision makers, and local authorities. In the current study, a GIS-based rockfall hazard assessm...

It's widely known that the procedures of soil erosion are affected by a number of physical and human factors and are appeared with different intensities in different places. However, the spatial and temporal scales of these procedures are still poorly understood. Therefore, the control and prediction of soil erosion and deposition are a complex and...

This study presents the synergy of multidisciplinary surveys for the monitoring of an active landslide in Western Greece. The aim of this paper is to highlight and validate a methodology based on multiple sensors data integration which can successfully be used to manage natural disasters or to improve the knowledge of a specific phenomenon in order...

Two of the most well known historical landslide occurrences are analyzed and their temporal evolution is presented. The sites of Panagopoula and Karya are often referred as the most representative cases of long term ground displacements based on inclinometer monitoring data. Regarding these cases, the heavy rainfalls constitute the main controlling...

The current paper presents the combined use of geological-geotechnical in situ data, remote sensing data and GIS techniques for the evaluation of a subsurface geological model. High-accuracy Digital Surface Model (DSM), air photos mosaic and satellite data, with a spatial resolution of 0.5m were used for an orthophoto base map compilation of the st...

An active landslide can be monitored using many different methods: Classical geotechnical measurements like inclinometer, topographical survey measurements with total stations or GPS and photogrammetric techniques using airphotos or high resolution satellite images. As the cost of the aerial photo campaign and the acquisition of very high resolutio...

In this paper a specific example of the synergistic use of geotechnical survey, remote sensing data and GIS for rockfall risk evaluation is presented. The study area is located in Western Greece. Extensive rockfalls have been recorded along Patras - Ioannina highway just after the cable-stayed bridge of Rio-Antirrio, at Klokova site. The rockfalls...

Some typical landslide phenomena in western Greece, in terms of the geological composition and structure of the affected materials, induced by heavy rainfalls are thoroughly studied and analyzed. The studied cases involved composite landslides on flysch and Neogene weak rock materials that constitute the most critical landslide prone geological for...

In this paper, restitution coefficients for various slope surfaces are proposed as obtained from back-analyses calculations that have been carried out in several sites in Western Greece affected by extensive rockfalls. These occurrences have been thoroughly studied in order to investigate the extent of the events, assess the hazard and propose prot...

Ο ολοκληρωμένος πολεοδομικός σχεδιασμός απαιτεί την πολύ καλή γνώση των χαρακτηριστικών του χώρου και τη διατύπωση λύσεων για την εξασφάλιση ανθρώπινων συνθηκών διαβίωσης. Στα πλαίσια αυτά απαιτούνται προτάσεις για την προστασία του δομημένου περιβάλλοντος από φυσικά καταστροφικά φαινόμενα και χρειάζεται ολοκληρωμένη γνώση των εδαφικών συνθηκών θεμ...

During August of 2007 several areas of Western Greece suffered one of the most devastating wildfires that have ever happened on European level. About 870 thousands of hectares, mainly forest and agricultural land, were lost, 63 people lost their lives, hundreds were injured and many towns and villages suffered extensive damage. Heavy and prolonged...

On the 8th of June 2008 an earthquake of magnitude Ms=6.5 occurred in Western Greece, affecting Achaia and Ilia Prefectures. According to state reports 2 casualties occurred, 214 people were injured and more than 15 villages and towns suffered extensive damages in properties and infrastructures. Among the secondary phenomena that were reported were...

In August 2007 Ilia Prefecture suffered one of the most devastating wildfires that have ever happened on European level. Approximately 870km2 , mainly forest and agricultural land, were lost, more than 60 people were killed, hundreds were injured and many villages suffered extensive damage. Heavy rainfall and human activities, favoured by the loss...

The present work demonstrates the environmental problems associated with the development and operation of a lined and unlined landfill site, both used for municipal solid waste landfilling, that are situated next to the city of Patra, Greece. Findings from a detailed site investigation as well calculations on hydrologic evaluation of landfill’s per...

Η αστυφιλία και η άναρχη ανάπτυξη των πόλεων και των χωριών είχαν ως αποτέλεσμα την τελευταία 30ετία του 20ου αιώνα στην Ελλάδα να παρουσιάζονται με αυξανόμενο ρυθμό προβλήματα στις πόλεις που είχαν σχέση με καταστροφές οι οποίες προκαλούνταν από φυσικά φαινόμενα, όπως είναι οι σεισμοί, οι κατολισθήσεις, οι πλημμύρες κ.α.. Οι γεωλογικές έρευνες άρχ...

Η παρούσα εργασία περιγράφει μία τεχνική για την ταξινόμηση των εδαφών σύμφωνα με τη ρυπαντική επιδεκτικότητα που εμφανίζουν, χρησιμοποιώντας τη συσκευή της υδραυλικής διαπερατότητας. Η τεχνική αυτή εφαρμόζεται στο εργαστήριο, εκτελώντας εργαστηριακές δοκιμές σε κορεσμένα εδαφικά διαταραγμένα δείγματα και διερευνώντας ταυτόχρονα τους μηχανισμούς δι...

Η παρούσα εργασία παρουσιάζει το νομικό πλαίσιο των γεωλογικών ερευνών που εφαρμόζεται στη χώρα μας κατά το χωροταξικό και πολεοδομικό σχεδιασμό και αναλύει τις περιπτώσεις που η οικιστική ανάπτυξη επηρεάζει ή επηρεάζεται από τα επιφανειακά και υπόγεια νερά. Σκοπός της εργασίας αυτής είναι η παρουσίαση όλων των γεωλογικών εργασιών, με ιδιαίτερη επι...

Electrical imaging (resistivity tomography) is increasingly used as a geophysical exploration technique in contaminated land research. The present work demonstrates the efficiency of electrical imaging in monitoring pollution plume evolution under both in-situ and model conditions. The in-situ campaign was done at an unlined landfill site situated...

In order to be able to track the movement of pollutant plumes during geotechnical centrifuge and other geo-environmental experiments, a number of techniques have been investigated: fibre-optic photometric sensors, resistivity probes, resistivity tomography, and copper ion-selective electrodes. Methods of image analysis, signal processing techniques...

This paper demonstrates the capabilities and limitations of a miniaturised electrical imaging technique (resistivity tomography) developed at Cardiff University to image contaminant plumes in scaled centrifuge models of the vadose zone. For this purpose a generic model of contaminant infiltration into unsaturated sand was designed. The imaging tech...

This paper reports results from centrifuge tests designed to investigate capillary rise in soils subjected to different gravitational fields. The experimental programme is part of the EU-funded NECER project (Network of European Centrifuges for Environmental Geotechnic Research), whose objective is to investigate the appropriateness of geotechnical...

The paper describes a fundamental study of capillary phenomena at elevated gravity, which was conducted as part of the research programme for the Network of European Centrifuges for Environmental Geotechnic Research (NECER) European Union co-operation programme. The aim of the study was to investigate the centrifuge scaling laws for a capillary ris...

The purpose of this work was to study the capabilities and limitations of a miniaturised electrical imaging (resistivity tomography) technique developed at Cardiff University to image contaminant plumes in scaled models of the vadose zone at different g-levels. For this purpose, a generic model of contaminant infiltration into partially-saturated s...

Thesis (Ph. D.)--University of Wales. Cardiff, 2000.

Contaminant plume evolution in the unsaturated zone depends strongly on capillary forces existing at the water-air interface. For this reason, the basic understanding of capillary phenomena is essential in any attempt to model contaminant behaviour in the unsaturated zone. This paper reports the experimental results from tests investigating capill...

This paper demonstrates the capabilities and limitations of a miniaturised electrical imaging technique (resistivity tomography) developed at Cardiff University to image contaminant plumes in scaled models of the vadose zone. For this purpose a generic model of contaminant infiltration into partially-saturated sand was designed to explore the poten...

This paper reviews geophysical exploration of the Riganokampos landfill site situated in the city of Patras, Achaia county, Greece and assesses hydrogeological conditions. Leachate derived from the deposited waste percolates towards the base of the landfill and then moves downward towards the aquifer at a rate defined by the hydrogeology of the sit...

This paper reviews the engineering geological conditions and the hydrogeological setting of the Riganokampos landfill. The site is underlain by a partially-saturated zone of alluvial fan deposits which retards leachate percolating to the underlying water table. However, leachate may still eventually migrate down gradient from the landfill site to p...