2025
Diakakis M, Sarantopoulou A, Gogou M, Filis C, Nastos P, Kapris I, Vassilakis E, Konsolaki A, Lekkas E.
Cascade Effects Induced by Extreme Storms and Floods: The Case of Storm Daniel (2023) in Greece. Water [Internet]. 2025;17(7):912.
https://doi.org/10.3390/w17070912AbstractThe anticipated rise in extreme flood events in the Eastern Mediterranean region indicates an increase in significant societal impacts that have the potential to extend beyond the flooded areas and affect multiple sectors. Despite the criticality of understanding storm and flood risk and how they propagate in modern interconnected societies, the scope and complexity of storm- and flood-triggered cascading effects are still poorly comprehended. This study explores the effects created by the extreme Storm Daniel, occurring in Thessaly, Greece in 2023, aiming to gather new evidence on the types and scale of these cascading effects by analyzing its impacts in the region through fieldwork and official data collection. The results, as a contribution to existing knowledge on cascade effects, provide insights into the nature, the extent, the propagation mechanisms, and the consequences of these triggering events leading to diverse cascade effects. The study identifies the interactions between different phenomena following this extreme storm event to offer a better understanding of how impacts propagate, and therefore a better understanding of future challenges connected with this type of cascading hazards framework, ultimately contributing to predicting and mitigating associated risks.
Misseyanni A, Christopoulou A, Kougkoulos I, Vassilakis E, Arianoutsou M.
The Impact of Forest Fires on Ecosystem Services: The Case of Greece. Forests [Internet]. 2025;16(3):533.
https://doi.org/10.3390/f16030533Abstract(1) Background: The present study examines the effects of fire on the ecosystem services of forest ecosystems in Greece. Being a Mediterranean country, Greece has been affected by fires of increasing intensity and frequency in recent years; (2) Methods: Information was extracted from 56 articles published in the period January 1997–March 2024 that were selected after an extensive literature review; (3) Results: An increasing trend in the number of published articles over time was observed. Studies on regulating and maintenance services prevailed. The majority of studies reported on thermo-Mediterranean ecosystems, with Pinus halepensis Mill forests being the most common ecosystems affected by fires. The effects of fire were primarily negative on provisioning and cultural services, as well as on the control of erosion rates, regulation of the hydrologic cycle, atmospheric composition, and climate regulation. Most effects on plant diversity were found to be positive, while positive and neutral effects were also recorded for pollination. The most pronounced negative or positive effects were noted for the first two years after the fire. The spatial mapping of the results showed that the areas most affected by the fires in Greece are Eastern Attica, Euboea, Western Attica, and most regional units of the Peloponnese; (4) Conclusions: In the era of climate change and changing fire regimes in the Mediterranean, there is a need to further research the impact of fire on ecosystem services, as this will help in the better protection and management of the most vulnerable forest ecosystems.
Spyrou N, Diakakis, Μ., Mavroulis, S., Deligiannakis, G., Andreadakis, Εmm., Filis, C., Kotsi, E., Antoniadis, A., Melaki, M., Gogou, A., et al. Ground observations and UAV mapping to support a GIS-based implementation of the Flash Flood Impact Severity Scale (FFISS) for the 2009 and 2020 flash floods in Evia, Greece. EGU General Assembly [Internet]. 2025:13306.
https://doi.org/10.5194/egusphere-egu25-13306,AbstractFlash floods have been responsible for some of the most catastrophic events globally. The extensive range of effects and the varying severity of impacts present significant challenges in accurately understanding the damage caused by a flood event, thereby hindering our capacity to predict future consequences. When evaluating flood impacts and their severity, most existing approaches rely on qualitative descriptions (e.g., major, catastrophic, etc.) or examine the impacts from a single perspective or discipline, such as economic losses. In this study, the Flash Flood Impact Severity Scale (FFISS) is employed to evaluate, map, and categorize the impacts of two flash floods that occurred in the Lilas River in Greece in 2009 and 2020. The goal of this application is to analyze the varying severity levels and how one flood event can influence the impacts of a subsequent event. The methodology involved extensive fieldwork, including the collection of ground-based and aerial observations using UAV technology to document the impacts. These observations were subsequently georeferenced, followed by applying the Flash Flood Impact Severity Scale (FFISS) and creating detailed maps to assess and evaluate the severity of impacts associated with the two flood events. The results indicate that, despite the higher water levels during the second flood, areas previously affected show lower severity values. This reduction is attributed to the community’s gradual adaptation, improvements in infrastructure, and significant local widening of the river channel. Conversely, newly flooded areas during the second event exhibit high severity levels. Overall, applying the FFISS reveals spatial patterns of impact severity, offering insights into the local nature of floods while suggesting a potential reduction in overall risk during the post-flood period.
Kotsi, E., Vassilakis, Emm., Diakakis, Μ., Mavroulis, S., Konsolaki, A., Filis, C., Lozios, S., Lekkas E.
Using UAS to Monitor and Quantify the Geomorphic Effects of extreme storms in tectonically active coastal areas: Evidence from Greece. EGU General Assembly [Internet]. 2025:20080.
https://doi.org/10.5194/egusphere-egu25-20080AbstractExtreme weather events, increasingly frequent in the Mediterranean due to climate change, pose significant risks by triggering hydrogeomorphic processes such as slope failures. These phenomena, particularly prevalent in tectonically active and steeply sloped coastal areas, present challenges for monitoring due to their spatial and temporal dynamics.Unmanned aerial systems (UAS) and advanced photogrammetric techniques, including structure-from-motion (SfM) and multi-view stereo (MVS), have emerged as transformative tools for capturing high-resolution terrain data. This study employs UAS-aided photogrammetry alongside change detection methods, such as digital elevation models of differences (DoD) and cloud-to-cloud distance (C2C), to analyze geomorphic changes induced by extreme storms in highly visited and geologically dynamic coastal areas in Greece.The findings reveal the utility of UAS in providing detailed morphometric measurements, delineating areas of erosion and deposition, and identifying high-risk zones. These capabilities facilitate a deeper understanding of geomorphic processes, enabling informed risk assessment and management strategies. The study underscores the potential of integrating UAS and photogrammetry for continuous monitoring in regions with high socioeconomic and environmental value. This approach not only supports sustainable development by minimizing disruptions but also enhances safety standards in vulnerable, high-exposure coastal areas. Through this methodological framework, the research contributes to addressing the pressing need for resilient hazard management in the context of evolving climatic conditions.
Diakakis, Μ., Kapris, I., Gogou, A., Sarantopoulou, A., Filis, C., Nastos, P., Vassilakis, Emm., Konsolaki, A., Lekkas E.
Cascading effects of extreme storms and floods: Evidence on impact propagating mechanisms. EGU General Assembly [Internet]. 2025:11513.
https://doi.org/10.5194/egusphere-egu25-11513AbstractThe increasing frequency and severity of extreme storms and floods in the Eastern Mediterranean under climate change pose significant challenges for modern societies. These events often trigger cascading effects that extend far beyond the immediate disaster zone, disrupting interconnected systems such as power, transportation, and communication networks. Despite advancements in flood risk management and growing awareness of cascading hazards, the mechanisms driving these interdependencies and their broader impacts remain poorly understood. This study investigates the cascading effects triggered by the catastrophic Storm Daniel, which struck Thessaly, Greece, in September 2023, as a case study to explore the nature, scale, and ways of impact propagation.This work also provides an analysis of cascading effects, based on evidence on historical storm and flood disaster impacts in the Mediterranean region, identifying the interactions between primary hazards (flooding, landslides, erosion) and secondary consequences as well as the diverse sectors that suffer impacts. The analysis reveals different propagation mechanisms of these effects, highlighting the vulnerability of interconnected systems as well as the vulnerability of the natural and the built environment. The cascading effects identified underscore systemic risks of modern societies posed by extreme events, particularly in urban areas with dense, interdependent, and critical infrastructure.The findings contribute to the growing body of literature on cascading disasters, addressing critical knowledge gaps in understanding how extreme weather events propagate through modern societal systems. These insights are particularly relevant in the context of climate change, which is expected to amplify the frequency and intensity of such events.
Mavroulis S, Lekkas E, Grambas A, Mavrouli M, Mokos V, Kourou A, Thoma T, Karagiannis F, Stamati E, Kaviris G, et al. Enhancing Preparedness and Resilience for Seismic Risk Reduction: The “Minoas 2024” Full-Scale Exercise for Earthquakes and Related Geohazards in Crete (Southern Greece). Geosciences [Internet]. 2025;15(2):59.
https://doi.org/10.3390/geosciences15020059AbstractIn early 2024, the largest full-scale exercise (FSE) for earthquakes and related geohazards in Greece was implemented in Crete Island (southern Greece). Crete is characterized by intense seismicity with historical and recent destructive earthquakes with considerable impact on both the natural and built environment and subsequently on the population. The uniqueness of this FSE lies in the creation and coordination of a multi-agency, multijurisdictional, and multidisciplinary environment in which a multitude of central, regional, and local stakeholders and a large percentage of the total population of Crete actively participated. This paper constitutes a descriptive study focusing on the main steps of the exercise management cycle comprising planning, implementation, and evaluation of the FSE. Furthermore, emphasis is given on its purpose and objectives, its main events and subsequent incidents, the participants and their roles, as well as the material developed and distributed to the participants. Through this study, the implemented actions for increasing preparedness of the Civil Protection mechanism in case of earthquakes and related geohazards are highlighted aiming to inform the scientific community and operational staff and to contribute to the seismic risk reduction of regions worldwide with similar seismotectonic and demographic characteristics with Crete. Furthermore, suggestions are made for the integration of multi-hazard episodes in the FSE scenario in order that the Civil Protection authorities will be prepared to handle the synergy of hazards of different types that may arise during a post-earthquake period that create compounding challenges during the emergency response and further increase recovery time.
Spyrou NI, Diakakis M, Mavroulis S, Deligiannakis G, Andreadakis E, Filis C, Kotsi E, Antoniadis Z, Melaki M, Vassilakis E, et al. Integrating Ground and UAV Mapping for GIS-Based Application of the Flash Flood Impact Severity Scale (FFISS) for the 2009 and 2020 Evia (Greece) Flash Floods. Applied Sciences [Internet]. 2025;15(3):1100.
https://doi.org/10.3390/app15031100AbstractFlash floods have been the cause of some of the most devastating events worldwide. The wide diversity of the effects, as well as the variety in the severity of the impacts, lead to major obstacles in obtaining a realistic understanding of the damages caused by a flood event, thus hampering at the same time our ability to predict future impacts. In assessing flood impacts and their severity, most existing methods use a qualitative characterization (e.g., major, catastrophic, etc.) or view the impacts from a single viewpoint or discipline (e.g., economic losses). In this study, we apply the Flash Flood Impact Severity Scale (FFISS) to assess, map, and classify the impacts of two flash floods from the Lilas River in Greece in 2009 and 2020. This application aims to discuss the different severity levels in terms of how one flood can affect the impacts of the next event. The methodology encompasses comprehensive field research, including the collection of ground-based and aerial observations utilizing UAV technology to document the impacts. These observations are subsequently georeferenced, followed by application of the Flash Flood Impact Severity Scale (FFISS) and generation of detailed maps to assess and evaluate the severity of the impacts associated with the two flood events. The results show that despite the higher water stage of the second flood, the impacts in previously hit areas indicate lower severity values, attributed to the gradual adaptation of the community and its infrastructure, as well as significant local widening of the river channel. On the contrary, high severity remains an issue in newly flooded areas during the second event. Overall, the application of the FFISS can show the spatial patterns of severity impacts, providing insights into the nature of floods locally but also indicating a potential reduction in the overall risk in the post-flood period.