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Water resources, especially riverine ecosystems, are globally under qualitative and quantitative degradation due to human-imposed pressures. High-temporal-resolution data obtained from automatic stations can provide insights into the processes that link catchment hydrology and streamwater chemistry. The scope of this paper was to investigate the statistical behavior of high-frequency measurements at sites with known hydromorphological and pollution pressures. For this purpose, hourly time series of water levels and key water quality indicators (temperature, electric conductivity, and dissolved oxygen concentrations) collected from four automatic monitoring stations under different hydromorphological conditions and pollution pressures were statistically elaborated. Based on the results, the hydromorphological conditions and pollution pressures of each station were confirmed to be reflected in the results of the statistical analysis performed. It was proven that the comparative use of the statistics and patterns of the water level and quality high-frequency time series could be used in the interpretation of the current site status as well as allowing the detection of possible changes. This approach can be used as a tool for the definition of thresholds, and will contribute to the design of management and restoration measures for the most impacted areas.
Angeliki Mentzafou; George Varlas; Anastasios Papadopoulos; Georgios Poulis; Elias Dimitriou. Assessment of Automatically Monitored Water Levels and Water Quality Indicators in Rivers with Different Hydromorphological Conditions and Pollution Levels in Greece. Hydrology 2021, 8, 86 .
AMA StyleAngeliki Mentzafou, George Varlas, Anastasios Papadopoulos, Georgios Poulis, Elias Dimitriou. Assessment of Automatically Monitored Water Levels and Water Quality Indicators in Rivers with Different Hydromorphological Conditions and Pollution Levels in Greece. Hydrology. 2021; 8 (2):86.
Chicago/Turabian StyleAngeliki Mentzafou; George Varlas; Anastasios Papadopoulos; Georgios Poulis; Elias Dimitriou. 2021. "Assessment of Automatically Monitored Water Levels and Water Quality Indicators in Rivers with Different Hydromorphological Conditions and Pollution Levels in Greece." Hydrology 8, no. 2: 86.
The adoption of Nature-Based Solutions (NBSs) represents a novel means to mitigate natural hazards. In the framework of the OPERANDUM project, this study introduces a methodology to assess the efficiency of the NBSs and a series of Open-Air Laboratories (OALs) regarded as a proof-of-concept for the wider uptake of NBSs. The OALs are located in Finland, Greece, UK, Italy, and Ireland. The methodology is based on a wide modeling activity, incorporated in the context of future climate scenarios. Herein, we present a series of models’ chains able to estimate the efficiency of the NBSs. While the presented models are mainly well-established, their coupling represents a first fundamental step in the study of the long-term efficacy and impact of the NBSs. In the selected sites, NBSs are utilized to cope with distinct natural hazards: floods, droughts, landslides, salt intrusion, and nutrient and sediment loading. The study of the efficacy of NBSs to mitigate these hazards belongs to a series of works devoted to the implementation of NBSs for environmental purposes. Our findings prove that land management plays a crucial role in the process. Specifically, the selected NBSs include intensive forestry; the conversion of urban areas to grassland; dunes; marine seagrass; water retention ponds; live cribwalls; and high-density plantations of woody vegetation and deep-rooted herbaceous vegetation. The management of natural resources should eventually consider the effect of NBSs on urban and rural areas, as their employment is becoming widespread.
Glauco Gallotti; Marco Santo; Ilektra Apostolidou; Jacopo Alessandri; Alberto Armigliato; Bidroha Basu; Sisay Debele; Alessio Domeneghetti; Alejandro Gonzalez-Ollauri; Prashant Kumar; Angeliki Mentzafou; Francesco Pilla; Beatrice Pulvirenti; Paolo Ruggieri; Jeetendra Sahani; Aura Salmivaara; Arunima Basu; Christos Spyrou; Nadia Pinardi; Elena Toth; Silvia Unguendoli; Umesh Pillai; Andrea Valentini; George Varlas; Giorgia Verri; Filippo Zaniboni; Silvana Di Sabatino. On the Management of Nature-Based Solutions in Open-Air Laboratories: New Insights and Future Perspectives. Resources 2021, 10, 36 .
AMA StyleGlauco Gallotti, Marco Santo, Ilektra Apostolidou, Jacopo Alessandri, Alberto Armigliato, Bidroha Basu, Sisay Debele, Alessio Domeneghetti, Alejandro Gonzalez-Ollauri, Prashant Kumar, Angeliki Mentzafou, Francesco Pilla, Beatrice Pulvirenti, Paolo Ruggieri, Jeetendra Sahani, Aura Salmivaara, Arunima Basu, Christos Spyrou, Nadia Pinardi, Elena Toth, Silvia Unguendoli, Umesh Pillai, Andrea Valentini, George Varlas, Giorgia Verri, Filippo Zaniboni, Silvana Di Sabatino. On the Management of Nature-Based Solutions in Open-Air Laboratories: New Insights and Future Perspectives. Resources. 2021; 10 (4):36.
Chicago/Turabian StyleGlauco Gallotti; Marco Santo; Ilektra Apostolidou; Jacopo Alessandri; Alberto Armigliato; Bidroha Basu; Sisay Debele; Alessio Domeneghetti; Alejandro Gonzalez-Ollauri; Prashant Kumar; Angeliki Mentzafou; Francesco Pilla; Beatrice Pulvirenti; Paolo Ruggieri; Jeetendra Sahani; Aura Salmivaara; Arunima Basu; Christos Spyrou; Nadia Pinardi; Elena Toth; Silvia Unguendoli; Umesh Pillai; Andrea Valentini; George Varlas; Giorgia Verri; Filippo Zaniboni; Silvana Di Sabatino. 2021. "On the Management of Nature-Based Solutions in Open-Air Laboratories: New Insights and Future Perspectives." Resources 10, no. 4: 36.
Among the Sustainable Development Goals (SDGs) established in the 2030 Agenda, goals 6.3, regarding clean water and improve of water quality, and 6.5, regarding integrated water resources management, highlight the need for the implementation of successful environmental water quality monitoring programs of transboundary river waterbodies. In the present study, the designation of high priority areas for water quality monitoring of Drin transboundary watershed is performed using a suitability model, a GIS-based multicriteria decision analysis (GIS-MCDA) approach that takes into consideration the most important conditioning factors that impose pressures on rivers. Based on the results, the methodological approach used manages to sufficiently delimit the areas with increased need for water quality monitoring in the Drin watershed, and the validation procedure produces a correlation coefficient of 0.454 (statistically significant at a 0.01 level). Limitations arise in the case of a lack of detailed information or inaccurate input data and due to the inconsistency among the input data and the different methodological approaches regarding the information collection of each country involved. These restrictions foreground the need for cooperation between the countries involved regarding the exchange of scientific knowledge and common legislation, so as to achieve integrated, effective, and sustainable management of water resources of the area.
Angeliki Mentzafou; Momčilo Blagojević; Elias Dimitriou. A GIS-MCDA-Based Suitability Analysis for Meeting Targets 6.3 and 6.5 of the Sustainable Development Goals. Sustainability 2021, 13, 4153 .
AMA StyleAngeliki Mentzafou, Momčilo Blagojević, Elias Dimitriou. A GIS-MCDA-Based Suitability Analysis for Meeting Targets 6.3 and 6.5 of the Sustainable Development Goals. Sustainability. 2021; 13 (8):4153.
Chicago/Turabian StyleAngeliki Mentzafou; Momčilo Blagojević; Elias Dimitriou. 2021. "A GIS-MCDA-Based Suitability Analysis for Meeting Targets 6.3 and 6.5 of the Sustainable Development Goals." Sustainability 13, no. 8: 4153.
Nature-based solutions (NBS) are being deployed around the world in order to address hydrometeorological hazards, including flooding, droughts, landslides and many others. The term refers to techniques inspired, supported and copied from nature, avoiding large constructions and other harmful interventions. In this work the development and evaluation of an NBS applied to the Spercheios river basin in Central Greece is presented. The river is susceptible to heavy rainfall and bank overflow, therefore the intervention selected is a natural water retention measure that aims to moderate the impact of flooding and drought in the area. After the deployment of the NBS, we examine the benefits under current and future climate conditions, using various climate change scenarios. Even though the NBS deployed is small compared to the rest of the river, its presence leads to a decrease in the maximum depth of flooding, maximum velocity and smaller flooded areas. Regarding the subsurface/groundwater storage under current and future climate change and weather conditions, the NBS construction seems to favor long-term groundwater recharge.
Christos Spyrou; Michael Loupis; Νikos Charizopoulos; Ilektra Apostolidou; Angeliki Mentzafou; George Varlas; Anastasios Papadopoulos; Elias Dimitriou; Depy Panga; Lamprini Gkeka; Paul Bowyer; Susanne Pfeifer; Sisay Debele; Prashant Kumar. Evaluating Nature-Based Solution for Flood Reduction in Spercheios River Basin under Current and Future Climate Conditions. Sustainability 2021, 13, 3885 .
AMA StyleChristos Spyrou, Michael Loupis, Νikos Charizopoulos, Ilektra Apostolidou, Angeliki Mentzafou, George Varlas, Anastasios Papadopoulos, Elias Dimitriou, Depy Panga, Lamprini Gkeka, Paul Bowyer, Susanne Pfeifer, Sisay Debele, Prashant Kumar. Evaluating Nature-Based Solution for Flood Reduction in Spercheios River Basin under Current and Future Climate Conditions. Sustainability. 2021; 13 (7):3885.
Chicago/Turabian StyleChristos Spyrou; Michael Loupis; Νikos Charizopoulos; Ilektra Apostolidou; Angeliki Mentzafou; George Varlas; Anastasios Papadopoulos; Elias Dimitriou; Depy Panga; Lamprini Gkeka; Paul Bowyer; Susanne Pfeifer; Sisay Debele; Prashant Kumar. 2021. "Evaluating Nature-Based Solution for Flood Reduction in Spercheios River Basin under Current and Future Climate Conditions." Sustainability 13, no. 7: 3885.
Heavy metal contamination of the aquatic environment is of worldwide concern, due to the toxicity of metals and their lethal effects on aquatic organisms. The detection of heavy metal concentrations in freshwater bodies has increased over the last decades in Greece; however, most studies have been sporadic and spatially limited. An overall assessment of the heavy metal contamination status in Greek surface water bodies is lacking. In this review, all available published data from 1999 to 2019 were collected and analysed to assess the heavy metal contamination status of the surface water bodies of Greece. Data were available for 68 water bodies and several pollution indices (e.g. Heavy Metal Pollution index, Geoaccumulation index, Moderated Pollution Index) were calculated to evaluate their surface water quality. Overall, heavy metal concentrations in water samples were below the Environmental Quality Standards (EQS) and the vast majority of water bodies were classified as good quality based on surface water pollution indices. Sediment heavy metal concentrations exceeding the Sediment Quality Guidelines (SQGs) were detected in most water bodies. Rivers Axios, Evros, Louros, Gallikos, Greveniotikos, Palea Kavala, Kompsatos, Alfeios and Evrotas, and lakes Pamvotis, Doirani and Koumoundourou were either moderately or highly contaminated. Up to date, heavy metal pollution indices used worldwide for surface waters refer to potable water. Thus, pollution indices must be developed for assessing primarily the ecological consequences of heavy metal pollution and surface water pollution status. Finally, sediment pollution guidelines must be suggested at a European or regional level.
Ioannis Karaouzas; Natalia Kapetanaki; Angeliki Mentzafou; Theodore D. Kanellopoulos; Nikolaos Skoulikidis. Heavy metal contamination status in Greek surface waters: A review with application and evaluation of pollution indices. Chemosphere 2020, 263, 128192 .
AMA StyleIoannis Karaouzas, Natalia Kapetanaki, Angeliki Mentzafou, Theodore D. Kanellopoulos, Nikolaos Skoulikidis. Heavy metal contamination status in Greek surface waters: A review with application and evaluation of pollution indices. Chemosphere. 2020; 263 ():128192.
Chicago/Turabian StyleIoannis Karaouzas; Natalia Kapetanaki; Angeliki Mentzafou; Theodore D. Kanellopoulos; Nikolaos Skoulikidis. 2020. "Heavy metal contamination status in Greek surface waters: A review with application and evaluation of pollution indices." Chemosphere 263, no. : 128192.
Severe hydrometeorological hazards such as floods, droughts, and thunderstorms are expected to increase in the future due to climate change. Due to the significant impacts of these phenomena, it is essential to develop new and advanced early warning systems for advance preparation of the population and local authorities (civil protection, government agencies, etc.). Therefore, reliable forecasts of extreme events, with high spatial and temporal resolution and a very short time horizon are needed, due to the very fast development and localized nature of these events. In very short time-periods (up to 6 h), small-scale phenomena can be described accurately by adopting a “nowcasting” approach, providing reliable short-term forecasts and warnings. To this end, a novel nowcasting system was developed and presented in this study, combining a data assimilation system (LAPS), a large amount of observed data, including XPOL radar precipitation measurements, the Chemical Hydrological Atmospheric Ocean wave System (CHAOS), and the WRF-Hydro model. The system was evaluated on the catastrophic flash flood event that occurred in the sub-urban area of Mandra in Western Attica, Greece, on 15 November 2017. The event was one of the most catastrophic flash floods with human fatalities (24 people died) and extensive infrastructure damage. The update of the simulations with assimilated radar data improved the initial precipitation description and led to an improved simulation of the evolution of the phenomenon. Statistical evaluation and comparison with flood data from the FloodHub showed that the nowcasting system could have provided reliable early warning of the flood event 1, 2, and even to 3 h in advance, giving vital time to the local authorities to mobilize and even prevent fatalities and injuries to the local population.
Christos Spyrou; George Varlas; Aikaterini Pappa; Angeliki Mentzafou; Petros Katsafados; Anastasios Papadopoulos; Marios Anagnostou; John Kalogiros. Implementation of a Nowcasting Hydrometeorological System for Studying Flash Flood Events: The Case of Mandra, Greece. Remote Sensing 2020, 12, 2784 .
AMA StyleChristos Spyrou, George Varlas, Aikaterini Pappa, Angeliki Mentzafou, Petros Katsafados, Anastasios Papadopoulos, Marios Anagnostou, John Kalogiros. Implementation of a Nowcasting Hydrometeorological System for Studying Flash Flood Events: The Case of Mandra, Greece. Remote Sensing. 2020; 12 (17):2784.
Chicago/Turabian StyleChristos Spyrou; George Varlas; Aikaterini Pappa; Angeliki Mentzafou; Petros Katsafados; Anastasios Papadopoulos; Marios Anagnostou; John Kalogiros. 2020. "Implementation of a Nowcasting Hydrometeorological System for Studying Flash Flood Events: The Case of Mandra, Greece." Remote Sensing 12, no. 17: 2784.
Spercheios River Basin and the adjacent Maliakos Gulf system (the Aegean Sea) in Central Greece is being examined under a holistic approach that perceives river basins and coastal marine areas as an integrated unit. The main scope is the better understanding of the impacts of the anthropogenic interventions and climate change to the ecological features and hydrochemical and biogeochemical processes taking place in the area. Based on the present study, the interlinkage between Spercheios River’s outflow and Maliakos Gulf is evident in all aspects of the physical environment. Spercheios River is the determining factor of Maliakos Gulf biodiversity and ecological status, due to the high rate of sedimentation that is affecting the geomorphological characteristics of the sea bottom. Moreover, the river’s discharge to the sea is affecting the physicochemical characteristics of the sea water, mainly salinity, especially near the estuaries. Additionally, the impact of anthropogenic activities and interventions are evident on the ecological status of water and sediments of both Spercheios Rivers and Maliakos Gulf samples. Possible climate change will lead to the decrease of precipitation rate and the increase of actual evapotranspiration that will negatively influence the water availability in the Spercheios River Basin. This will directly impact the aquatic ecosystems and Maliakos Gulf hydrodynamics, will affect the spatiotemporal distribution of temperature and salinity, and will inevitably affect the inflows and distribution of nutrients in the sea and the fish fauna composition and populations. An integrated water resource management and adaptive management framework that incorporates the human dimensions into water resource governance is proposed.
Angeliki Mentzafou; Vassiliki Markogianni; Anastasios Papadopoulos; Alexandra Pavlidou; Christos Tziavos; Elias Dimitriou. The Impacts of Anthropogenic and Climatic Factors on the Interaction of Spercheios River and Maliakos Gulf, the Aegean Sea. The Handbook of Environmental Chemistry 2020, 1 -33.
AMA StyleAngeliki Mentzafou, Vassiliki Markogianni, Anastasios Papadopoulos, Alexandra Pavlidou, Christos Tziavos, Elias Dimitriou. The Impacts of Anthropogenic and Climatic Factors on the Interaction of Spercheios River and Maliakos Gulf, the Aegean Sea. The Handbook of Environmental Chemistry. 2020; ():1-33.
Chicago/Turabian StyleAngeliki Mentzafou; Vassiliki Markogianni; Anastasios Papadopoulos; Alexandra Pavlidou; Christos Tziavos; Elias Dimitriou. 2020. "The Impacts of Anthropogenic and Climatic Factors on the Interaction of Spercheios River and Maliakos Gulf, the Aegean Sea." The Handbook of Environmental Chemistry , no. : 1-33.
In this study, the physically-based hydrological model MIKE SHE was employed to investigate the effects of anthropogenic land cover changes to the hydrological cycle components of a regional watershed in Central Greece. Three case studies based on the land cover of the years 1960, 1990, and 2018 were examined. Copernicus Climate Change Service E-OBS gridded meteorological data for 45 hydrological years were used as forcing for the model. Evaluation against observational data yielded sufficient quality for daily air temperature and precipitation. Simulation results demonstrated that the climatic variabilities primarily in precipitation and secondarily in air temperature affected basin-averaged annual actual evapotranspiration and average annual river discharge. Nevertheless, land cover effects can locally outflank the impact of climatic variability as indicated by the low interannual variabilities of differences in annual actual evapotranspiration among case studies. The transition from forest to pastures or agricultural land reduced annual actual evapotranspiration and increased average annual river discharge while intensifying the vulnerability to hydrometeorological-related hazards such as droughts or floods. Hence, the quantitative assessment of land cover effects presented in this study can contribute to the design and implementation of successful land cover and climate change mitigation and adaptation policies.
Angeliki Mentzafou; George Varlas; Elias Dimitriou; Anastasios Papadopoulos; Ioannis Pytharoulis; Petros Katsafados. Modeling the Effects of Anthropogenic Land Cover Changes to the Main Hydrometeorological Factors in a Regional Watershed, Central Greece. Climate 2019, 7, 129 .
AMA StyleAngeliki Mentzafou, George Varlas, Elias Dimitriou, Anastasios Papadopoulos, Ioannis Pytharoulis, Petros Katsafados. Modeling the Effects of Anthropogenic Land Cover Changes to the Main Hydrometeorological Factors in a Regional Watershed, Central Greece. Climate. 2019; 7 (11):129.
Chicago/Turabian StyleAngeliki Mentzafou; George Varlas; Elias Dimitriou; Anastasios Papadopoulos; Ioannis Pytharoulis; Petros Katsafados. 2019. "Modeling the Effects of Anthropogenic Land Cover Changes to the Main Hydrometeorological Factors in a Regional Watershed, Central Greece." Climate 7, no. 11: 129.
Water quality indices that describe the status of water are commonly used in freshwater vulnerability assessment. The design of river water quality monitoring programs has always been a complex process and despite the numerous methodologies employed by experts, there is still no generally accepted, holistic and practical approach to support all the phases and elements related. Here, a Geographical Information System (GIS)-based multicriteria decision analysis approach was adopted so as to contribute to the design of the national network for monitoring of water quality parameters in Greece that will additionally fulfill the urgent needs for an operational, real-time monitoring of the water resources. During this cost-effective and easily applied procedure the high priority areas were defined by taking into consideration the most important conditioning factors that impose pressures on rivers and the special conditions that increase the need for monitoring locally. The areas of increased need for automatic monitoring of water quality parameters are highlighted and the output map is validated. The sites in high priority areas are proposed for the installation of automatic monitoring stations and the installation and maintenance budget is presented. Finally, the proposed network is contrasted with the current automatic monitoring network in Greece.
Angeliki Mentzafou; Yiannis Panagopoulos; Elias Dimitriou. Designing the National Network for Automatic Monitoring of Water Quality Parameters in Greece. Water 2019, 11, 1310 .
AMA StyleAngeliki Mentzafou, Yiannis Panagopoulos, Elias Dimitriou. Designing the National Network for Automatic Monitoring of Water Quality Parameters in Greece. Water. 2019; 11 (6):1310.
Chicago/Turabian StyleAngeliki Mentzafou; Yiannis Panagopoulos; Elias Dimitriou. 2019. "Designing the National Network for Automatic Monitoring of Water Quality Parameters in Greece." Water 11, no. 6: 1310.
Global water resources are currently under increasing pressures that lead to their quantitative and qualitative degradation. Humanly imposed modifications of the environment lead to the deterioration of the quality and availability of the water resources, especially of vulnerable coastal, karstic systems. Towards the better understanding of the karst operational mechanisms, time series analysis is often employed, especially in lack of other resources. Under this scope, daily and hourly time-series of physicochemical characteristics (temperature, dissolved oxygen and electrical conductivity) for the period 2011–2015 at an especially vulnerable coastal wetland (Koumoundourou Lake, Athens, Greece) were statistically processed and analysed, so as to investigate the response of the lagoon to the underwater recharging karst system and the driving biological processes. Based on the results, the physicochemical variables are largely controlled by the groundwater inflows or sea water intrusion and macrophytes affect dissolved oxygen fluctuations. Precipitation affects the system after 72–79 days, while meteorological variables affect significantly the water temperature and electrical conductivity of the lagoon. Biological processes and freshwater inflows rather than climate factors seems to affect dissolved oxygen concentrations.
A. Mentzafou; E. Dimitriou. Time Series Analysis of the Physicochemical Parameters and Meteorological Factors in a Mediterranean Lagoon. Environmental Processes 2019, 6, 119 -134.
AMA StyleA. Mentzafou, E. Dimitriou. Time Series Analysis of the Physicochemical Parameters and Meteorological Factors in a Mediterranean Lagoon. Environmental Processes. 2019; 6 (1):119-134.
Chicago/Turabian StyleA. Mentzafou; E. Dimitriou. 2019. "Time Series Analysis of the Physicochemical Parameters and Meteorological Factors in a Mediterranean Lagoon." Environmental Processes 6, no. 1: 119-134.
Urban areas often experience high precipitation rates and heights associated with flash flood events. Atmospheric and hydrological models in combination with remote-sensing and surface observations are used to analyze these phenomena. This study aims to conduct a hydrometeorological analysis of a flash flood event that took place in the sub-urban area of Mandra, western Attica, Greece, using remote-sensing observations and the Chemical Hydrological Atmospheric Ocean Wave System (CHAOS) modeling system that includes the Advanced Weather Research Forecasting (WRF-ARW) model and the hydrological model (WRF-Hydro). The flash flood was caused by a severe storm during the morning of 15 November 2017 around Mandra area resulting in extensive damages and 24 fatalities. The X-band dual-polarization (XPOL) weather radar of the National Observatory of Athens (NOA) observed precipitation rates reaching 140 mm/h in the core of the storm. CHAOS simulation unveils the persistent orographic convergence of humid southeasterly airflow over Pateras mountain as the dominant parameter for the evolution of the storm. WRF-Hydro simulated the flood using three different precipitation estimations as forcing data, obtained from the CHAOS simulation (CHAOS-hydro), the XPOL weather radar (XPOL-hydro) and the Global Precipitation Measurement (GMP)/Integrated Multi-satellitE Retrievals for GPM (IMERG) satellite dataset (GPM/IMERG-hydro). The findings indicate that GPM/IMERG-hydro underestimated the flood magnitude. On the other hand, XPOL-hydro simulation resulted to discharge about 115 m3/s and water level exceeding 3 m in Soures and Agia Aikaterini streams, which finally inundated. CHAOS-hydro estimated approximately the half water level and even lower discharge compared to XPOL-hydro simulation. Comparing site-detailed post-surveys of flood extent, XPOL-hydro is characterized by overestimation while CHAOS-hydro and GPM/IMERG-hydro present underestimation. However, CHAOS-hydro shows enough skill to simulate the flooded areas despite the forecast inaccuracies of numerical weather prediction. Overall, the simulation results demonstrate the potential benefit of using high-resolution observations from a X-band dual-polarization radar as an additional forcing component in model precipitation simulations.
George Varlas; Marios N. Anagnostou; Christos Spyrou; Anastasios Papadopoulos; John Kalogiros; Angeliki Mentzafou; Silas Michaelides; Evangelos Baltas; Efthimios Karymbalis; Petros Katsafados. A Multi-Platform Hydrometeorological Analysis of the Flash Flood Event of 15 November 2017 in Attica, Greece. Remote Sensing 2018, 11, 45 .
AMA StyleGeorge Varlas, Marios N. Anagnostou, Christos Spyrou, Anastasios Papadopoulos, John Kalogiros, Angeliki Mentzafou, Silas Michaelides, Evangelos Baltas, Efthimios Karymbalis, Petros Katsafados. A Multi-Platform Hydrometeorological Analysis of the Flash Flood Event of 15 November 2017 in Attica, Greece. Remote Sensing. 2018; 11 (1):45.
Chicago/Turabian StyleGeorge Varlas; Marios N. Anagnostou; Christos Spyrou; Anastasios Papadopoulos; John Kalogiros; Angeliki Mentzafou; Silas Michaelides; Evangelos Baltas; Efthimios Karymbalis; Petros Katsafados. 2018. "A Multi-Platform Hydrometeorological Analysis of the Flash Flood Event of 15 November 2017 in Attica, Greece." Remote Sensing 11, no. 1: 45.
The water quality of Koumoundourou Lake, a heavily modified, peri-urban, brackish and shallow lake near Athens, Greece, is under multiple stressors due to the industrial activities in the catchment area and natural pollution pressures. Although the broader area has undergone significant land use changes since the beginning of the 20th century converting it from rural to heavily industrialized, Koumoundourou Lake remained as one of the few habitats in Attica Region, for large numbers of aquatic birds. The water quality of the lake has been recently improved, which contributed to the increase of aquatic birds' population in the area and to the higher, in relation to the past, nitrogen inputs from natural sources. Therefore, a monitoring program has been implemented to assess the pollution pressure factors in the lake. A water quality model has been also used to simulate the lake's processes and estimate the nutrient mass budget focusing on the various nitrogen loading mechanisms (natural and anthropogenic). Based on the model output, the main polluting factor of the lake is the groundwater inflows. Aquatic birds affect slightly the lake's water quality, while the dry and wet atmospheric deposition contributes insignificantly to the total nitrogen loading.
Angeliki Mentzafou; E. Dimitriou. Nitrogen loading and natural pressures on the water quality of a shallow Mediterranean lake. Science of The Total Environment 2018, 646, 134 -143.
AMA StyleAngeliki Mentzafou, E. Dimitriou. Nitrogen loading and natural pressures on the water quality of a shallow Mediterranean lake. Science of The Total Environment. 2018; 646 ():134-143.
Chicago/Turabian StyleAngeliki Mentzafou; E. Dimitriou. 2018. "Nitrogen loading and natural pressures on the water quality of a shallow Mediterranean lake." Science of The Total Environment 646, no. : 134-143.
Identifying the historical hydrometeorological trends in a river basin is necessary for understanding the dominant interactions between climate, human activities and local hydromorphological conditions. Estimating the hydrological reference conditions in a river is also crucial for estimating accurately the impacts from human water related activities and design appropriate water management schemes. In this effort, the output of a regional past climate model was used, covering the period from 1660 to 1990, in combination with a dynamic, spatially distributed, hydrologic model to estimate the past and recent trends in the main hydrologic parameters such as overland flow, water storages and evapotranspiration, in a Mediterranean river basin. The simulated past hydrologic conditions (1660–1960) were compared with the current hydrologic regime (1960–1990), to assess the magnitude of human and natural impacts on the identified hydrologic trends. The hydrological components of the recent period of 2008–2016 were also examined in relation to the impact of human activities. The estimated long-term trends of the hydrologic parameters were partially assigned to varying atmospheric forcing due to volcanic activity combined with spontaneous meteorological fluctuations.
A. Mentzafou; S. Wagner; E. Dimitriou. Historical trends and the long-term changes of the hydrological cycle components in a Mediterranean river basin. Science of The Total Environment 2018, 636, 558 -568.
AMA StyleA. Mentzafou, S. Wagner, E. Dimitriou. Historical trends and the long-term changes of the hydrological cycle components in a Mediterranean river basin. Science of The Total Environment. 2018; 636 ():558-568.
Chicago/Turabian StyleA. Mentzafou; S. Wagner; E. Dimitriou. 2018. "Historical trends and the long-term changes of the hydrological cycle components in a Mediterranean river basin." Science of The Total Environment 636, no. : 558-568.
Temporary rivers are dynamic and complex ecosystems that are widespread in arid and semi-arid regions, such as the Mediterranean. Biotic communities adapted in their intermittent nature could withstand recurrent drought events. However, anthropogenic disturbances in the form of water stress and chemical pollution challenge biota with unpredictable outcomes, especially in view of climate change. In this study we assess the response of the biotic community of a temporary river to environmental stressors, focusing on water stress and pollution. Towards this aim, several metrics of four biotic groups (diatoms, macrophytes, macroinvertebrates and fish) were applied. All biotic groups responded to a pollution gradient mainly driven by land use, distinct functional groups of all biota responded to water stress (a response related to the rheophilic nature of the species and their resistance to shear stress), while the combined effects of water stress and pollution were apparent in fish. Biotic groups presented a differential temporal response to water stress, where diatom temporal assemblage patterns were explained by water stress variables of short-time response (15days), while the responses of the other biota were associated to longer time periods. There were two time periods of fish response, a short (15days) and a long-time response (60-75days). When considering management decisions, our results indicate that, given the known response of river biota to pollution, biomonitoring of temporary rivers should also involve metrics that can be utilized as early warnings of water stress.
Ioannis Karaouzas; Evangelia Smeti; Aikaterini Vourka; Leonidas Vardakas; Aggeliki Mentzafou; Elisabet Tornés; Sergi Sabater; Isabel Muñoz; Nikolaos Th. Skoulikidis; Eleni Kalogianni. Assessing the ecological effects of water stress and pollution in a temporary river - Implications for water management. Science of The Total Environment 2018, 618, 1591 -1604.
AMA StyleIoannis Karaouzas, Evangelia Smeti, Aikaterini Vourka, Leonidas Vardakas, Aggeliki Mentzafou, Elisabet Tornés, Sergi Sabater, Isabel Muñoz, Nikolaos Th. Skoulikidis, Eleni Kalogianni. Assessing the ecological effects of water stress and pollution in a temporary river - Implications for water management. Science of The Total Environment. 2018; 618 ():1591-1604.
Chicago/Turabian StyleIoannis Karaouzas; Evangelia Smeti; Aikaterini Vourka; Leonidas Vardakas; Aggeliki Mentzafou; Elisabet Tornés; Sergi Sabater; Isabel Muñoz; Nikolaos Th. Skoulikidis; Eleni Kalogianni. 2018. "Assessing the ecological effects of water stress and pollution in a temporary river - Implications for water management." Science of The Total Environment 618, no. : 1591-1604.
Sustainable water basin management requires characterization of flow regime in river networks impacted by anthropogenic pressures. Flow regime in ungauged catchments under current, future, or natural conditions can be assessed with hydrological models. Developing hydrological models is, however, resource demanding such that decision makers might revert to models that have been developed for other purposes and are made available to them ('off-the-shelf' models). In this study, the impact of epistemic uncertainty of flow regime indicators on flow-ecological assessment was assessed at selected stations with drainage areas ranging from about 400 to almost 90,000km in four South European basins (Adige, Ebro, Evrotas and Sava). For each basin, at least two models were employed. Models differed in structure, data input, spatio-temporal resolution, and calibration strategy, reflecting the variety of conditions and purposes for which they were initially developed. The uncertainty of modelled flow regime was assessed by comparing the modelled hydrologic indicators of magnitude, timing, duration, frequency and rate of change to those obtained from observed flow. The results showed that modelled flow magnitude indicators at medium and high flows were generally reliable, whereas indicators for flow timing, duration, and rate of change were affected by large uncertainties, with correlation coefficients mostly below 0.50. These findings mirror uncertainty in flow regime indicators assessed with other methods, including from measured streamflow. The large indicator uncertainty may significantly affect assessment of ecological status in freshwater systems, particularly in ungauged catchments. Finally, flow-ecological assessments proved very sensitive to reference flow regime (i.e., without anthropogenic pressures). Model simulations could not adequately capture flow regime in the reference sites comprised in this study. The lack of reliable reference conditions may seriously hamper flow-ecological assessments. This study shows the pressing need for improving assessment of natural flow regime at pan-European scale.
Olga Vigiak; Stefanie Lutz; Angeliki Mentzafou; Gabriele Chiogna; Ye Tuo; Bruno Majone; Hylke Beck; Ad de Roo; Anna Malagó; Fayçal Bouraoui; Rohini Kumar; Luis Samaniego; Ralf Merz; Christos Gamvroudis; Nikolaos Skoulikidis; Nikolaos Nikolaidis; Alberto Bellin; Vicenç Acuňa; Nataša Mori; Ralf Ludwig; Alberto Pistocchi. Uncertainty of modelled flow regime for flow-ecological assessment in Southern Europe. Science of The Total Environment 2018, 615, 1028 -1047.
AMA StyleOlga Vigiak, Stefanie Lutz, Angeliki Mentzafou, Gabriele Chiogna, Ye Tuo, Bruno Majone, Hylke Beck, Ad de Roo, Anna Malagó, Fayçal Bouraoui, Rohini Kumar, Luis Samaniego, Ralf Merz, Christos Gamvroudis, Nikolaos Skoulikidis, Nikolaos Nikolaidis, Alberto Bellin, Vicenç Acuňa, Nataša Mori, Ralf Ludwig, Alberto Pistocchi. Uncertainty of modelled flow regime for flow-ecological assessment in Southern Europe. Science of The Total Environment. 2018; 615 ():1028-1047.
Chicago/Turabian StyleOlga Vigiak; Stefanie Lutz; Angeliki Mentzafou; Gabriele Chiogna; Ye Tuo; Bruno Majone; Hylke Beck; Ad de Roo; Anna Malagó; Fayçal Bouraoui; Rohini Kumar; Luis Samaniego; Ralf Merz; Christos Gamvroudis; Nikolaos Skoulikidis; Nikolaos Nikolaidis; Alberto Bellin; Vicenç Acuňa; Nataša Mori; Ralf Ludwig; Alberto Pistocchi. 2018. "Uncertainty of modelled flow regime for flow-ecological assessment in Southern Europe." Science of The Total Environment 615, no. : 1028-1047.
Elias Dimitriou; Ioannis Panagiotopoulos; Angeliki Mentzafou; Christos Anagnostou. ASSESSING THE ANTHROPOGENIC IMPACTS ON THE FLUVIAL WATER AND SEDIMENT FLUXES INTO THE THERMAIKOS GULF, NORTHERN GREECE. Environmental Engineering and Management Journal 2018, 17, 1053 -1068.
AMA StyleElias Dimitriou, Ioannis Panagiotopoulos, Angeliki Mentzafou, Christos Anagnostou. ASSESSING THE ANTHROPOGENIC IMPACTS ON THE FLUVIAL WATER AND SEDIMENT FLUXES INTO THE THERMAIKOS GULF, NORTHERN GREECE. Environmental Engineering and Management Journal. 2018; 17 (5):1053-1068.
Chicago/Turabian StyleElias Dimitriou; Ioannis Panagiotopoulos; Angeliki Mentzafou; Christos Anagnostou. 2018. "ASSESSING THE ANTHROPOGENIC IMPACTS ON THE FLUVIAL WATER AND SEDIMENT FLUXES INTO THE THERMAIKOS GULF, NORTHERN GREECE." Environmental Engineering and Management Journal 17, no. 5: 1053-1068.
Many scientists link climate change to the increase of the extreme weather phenomena frequency, which combined with land use changes often lead to disasters with severe social and economic effects. Especially floods as a consequence of heavy rainfall can put vulnerable human and natural systems such as transboundary wetlands at risk. In order to meet the European Directive 2007/60/EC requirements for the development of flood risk management plans, the flood hazard map of Evros transboundary watershed was produced after a grid-based GIS modelling method that aggregates the main factors related to the development of floods: topography, land use, geology, slope, flow accumulation and rainfall intensity. The verification of this tool was achieved through the comparison between the produced hazard map and the inundation maps derived from the supervised classification of Landsat 5 and 7 satellite imageries of four flood events that took place at Evros delta proximity, a wetland of international importance. The comparison of the modelled output (high and very high flood hazard areas) with the extent of the inundated areas as mapped from the satellite data indicated the satisfactory performance of the model. Furthermore, the vulnerability of each land use against the flood events was examined. Geographically Weighted Regression has also been applied between the final flood hazard map and the major factors in order to ascertain their contribution to flood events. The results accredited the existence of a strong relationship between land uses and flood hazard indicating the flood susceptibility of the lowlands and agricultural land. A dynamic transboundary flood hazard management plan should be developed in order to meet the Flood Directive requirements for adequate and coordinated mitigation practices to reduce flood risk.
Angeliki Mentzafou; Vasiliki Markogianni; Elias Dimitriou. The Use of Geospatial Technologies in Flood Hazard Mapping and Assessment: Case Study from River Evros. Geoinformatics and Atmospheric Science 2017, 221 -242.
AMA StyleAngeliki Mentzafou, Vasiliki Markogianni, Elias Dimitriou. The Use of Geospatial Technologies in Flood Hazard Mapping and Assessment: Case Study from River Evros. Geoinformatics and Atmospheric Science. 2017; ():221-242.
Chicago/Turabian StyleAngeliki Mentzafou; Vasiliki Markogianni; Elias Dimitriou. 2017. "The Use of Geospatial Technologies in Flood Hazard Mapping and Assessment: Case Study from River Evros." Geoinformatics and Atmospheric Science , no. : 221-242.
The Spercheios river basin—coastal marine area is a complex natural and interdependent ecosystem, highly affected by human activities and interventions. Such sensitive systems are even more vulnerable to alterations of the hydrological cycle components and it is likely to be rapidly and severely affected by climate change. In order to examine the climate change impacts on water resources of the study area, the interaction between the hydrology of the river basin and the hydrodynamic of the coastal marine area was examined using two models. Based on the results, although the irrigation needs decrease for the years 2050 and 2100 due to corresponding decrease in cultivated areas, temperature increase and precipitation decrease are both expected to influence the water resources of the Spercheios river basin, which will directly affect the Maliakos Gulf hydrodynamics. The necessity to adopt a holistic approach which will treat river basins and coastal marine areas as an integrated whole, with regard to environmental, socio-economic and political framework, is evident.
Angeliki Mentzafou; Chrysa Vamvakaki; Ierotheos Zacharias; Areti Gianni; Elias Dimitriou. Climate change impacts on a Mediterranean river and the associated interactions with the adjacent coastal area. Environmental Earth Sciences 2017, 76, 259 .
AMA StyleAngeliki Mentzafou, Chrysa Vamvakaki, Ierotheos Zacharias, Areti Gianni, Elias Dimitriou. Climate change impacts on a Mediterranean river and the associated interactions with the adjacent coastal area. Environmental Earth Sciences. 2017; 76 (6):259.
Chicago/Turabian StyleAngeliki Mentzafou; Chrysa Vamvakaki; Ierotheos Zacharias; Areti Gianni; Elias Dimitriou. 2017. "Climate change impacts on a Mediterranean river and the associated interactions with the adjacent coastal area." Environmental Earth Sciences 76, no. 6: 259.
Leonidas Vardakas; Eleni Kalogianni; Christina Papadaki; Theocharis Vavalidis; Angeliki Mentzafou; Drosos Koutsoubas; Nikolaos Skoulikidis Th.. Defining critical habitat conditions for the conservation of three endemic and endangered cyprinids in a Mediterranean intermittent river before the onset of drought. Aquatic Conservation: Marine and Freshwater Ecosystems 2017, 27, 1270 -1280.
AMA StyleLeonidas Vardakas, Eleni Kalogianni, Christina Papadaki, Theocharis Vavalidis, Angeliki Mentzafou, Drosos Koutsoubas, Nikolaos Skoulikidis Th.. Defining critical habitat conditions for the conservation of three endemic and endangered cyprinids in a Mediterranean intermittent river before the onset of drought. Aquatic Conservation: Marine and Freshwater Ecosystems. 2017; 27 (6):1270-1280.
Chicago/Turabian StyleLeonidas Vardakas; Eleni Kalogianni; Christina Papadaki; Theocharis Vavalidis; Angeliki Mentzafou; Drosos Koutsoubas; Nikolaos Skoulikidis Th.. 2017. "Defining critical habitat conditions for the conservation of three endemic and endangered cyprinids in a Mediterranean intermittent river before the onset of drought." Aquatic Conservation: Marine and Freshwater Ecosystems 27, no. 6: 1270-1280.
Many scientists link climate change to the increase of the extreme weather phenomena frequency, which combined with land use changes often lead to disasters with severe social and economic effects. Especially floods as a consequence of heavy rainfall can put vulnerable human and natural systems such as transboundary wetlands at risk. In order to meet the European Directive 2007/60/EC requirements for the development of flood risk management plans, the flood hazard map of Evros transboundary watershed was produced after a grid-based GIS modelling method that aggregates the main factors related to the development of floods: topography, land use, geology, slope, flow accumulation and rainfall intensity. The verification of this tool was achieved through the comparison between the produced hazard map and the inundation maps derived from the supervised classification of Landsat 5 and 7 satellite imageries of four flood events that took place at Evros delta proximity, a wetland of international importance. The comparison of the modelled output (high and very high flood hazard areas) with the extent of the inundated areas as mapped from the satellite data indicated the satisfactory performance of the model. Furthermore, the vulnerability of each land use against the flood events was examined. Geographically Weighted Regression has also been applied between the final flood hazard map and the major factors in order to ascertain their contribution to flood events. The results accredited the existence of a strong relationship between land uses and flood hazard indicating the flood susceptibility of the lowlands and agricultural land. A dynamic transboundary flood hazard management plan should be developed in order to meet the Flood Directive requirements for adequate and coordinated mitigation practices to reduce flood risk.
Angeliki Mentzafou; Vasiliki Markogianni; Elias Dimitriou. The Use of Geospatial Technologies in Flood Hazard Mapping and Assessment: Case Study from River Evros. Pure and Applied Geophysics 2016, 174, 679 -700.
AMA StyleAngeliki Mentzafou, Vasiliki Markogianni, Elias Dimitriou. The Use of Geospatial Technologies in Flood Hazard Mapping and Assessment: Case Study from River Evros. Pure and Applied Geophysics. 2016; 174 (2):679-700.
Chicago/Turabian StyleAngeliki Mentzafou; Vasiliki Markogianni; Elias Dimitriou. 2016. "The Use of Geospatial Technologies in Flood Hazard Mapping and Assessment: Case Study from River Evros." Pure and Applied Geophysics 174, no. 2: 679-700.