Papers by Georgios Stamatis
Water
A novel index-based method (RIVA) for assessing intrinsic groundwater vulnerability was applied t... more A novel index-based method (RIVA) for assessing intrinsic groundwater vulnerability was applied to Tirnavos basin (central Greece) to assess the susceptibility to surface-released contamination. Data from field surveys, previous studies, and literature were used to calculate the factors that compile the RIVA method. The aggregated results delineated the spatial distribution of groundwater vulnerability from very low to very high. The modelled results were successfully validated with ground-truth values of nitrates obtained from 43 boreholes. Overall, the modelled and the monitored values match more than 80%, indicating the successful application of the RIVA method. Few deviations were observed in areas dominantly affected by lateral crossflows and contamination from adjacent areas. RIVA proved an efficient method in terms of accuracy, data intensity, and investment to reach highly accurate results. Overall, RIVA proved to be a robust tool for reliable groundwater vulnerability asses...
ECWS-7 2023
The goal of our investigation is the hydrological 2D modelling of Lithaios River's (Central Greec... more The goal of our investigation is the hydrological 2D modelling of Lithaios River's (Central Greece) streamflow, using GIS and geostatistics for studying water velocity and discharge, stage elevation, and hydraulic features (streamflow depth, water flow area, wettable circumference, hydraulic radius and depth, n Manning's coefficient, Chow's composite n, Froude number, etc.). Moreover, compilations and validations of rating curves (RC) were performed from a series of stage h(t)-discharge Q(t) couples metrics, aiming to use these as a river toolkit to aid environmental and agriculture surface water resources management and help environmental flows calculation, streamflow tracking, and irrigation programming in the regional basin range. The statistical results showed that the Froude number during the study period was Fr < 1 showing that Lithaios River's streamflow is classified as subcritical. The models' validation outcomes by using various statistics and geostatistical alternative methods, model simulations and statistics errors criterions, were correlated with the retrieved power models' streamflow data matching for the RC curves and 2D GIS modelling and mapping of river velocity and discharge relationships and were highly satisfying since the stabilities of the deployed relationships were solid. The outcomes of the study results are recommended to provide a hydrological serving toolkit for environmental water resources administration and irrigation programming. This toolkit could assist water supply principalities to rapidly and precisely calculate streamflow volumes and features with a minimal cost rate and workload, and it could be engaged in water supply and agricultural watering administration, the calculation of environmental flows, flood protection, groundwater recharge, and other objectives.
Water
A combined hydrogeochemical and hydrodynamic characterization for the assessment of key aspects r... more A combined hydrogeochemical and hydrodynamic characterization for the assessment of key aspects related to groundwater resources management was performed in a highly productive agricultural basin of the Thessaly region in central Greece. A complementary suite of tools and methods—including graphical processing, hydrogeochemical modeling, multivariate statistics and environmental isotopes—have been applied to a comprehensive dataset of physicochemical analyses and water level measurements. Results revealed that the initial hydrogeochemistry of groundwater was progressively impacted by secondary phenomena (e.g., ion exchange and redox reactions) which were clearly delineated into distinct zones according to data processing. The progressive evolution of groundwater was further verified by the variation of the saturation indices of critical minerals. In addition, the combined use of water level measurements delineated the major pathways of groundwater flow. Interestingly, the additional...
The recent years’ groundwater degradation is mainly related to the intensification of agriculture... more The recent years’ groundwater degradation is mainly related to the intensification of agriculture, the unreasonable use of chemical fertilizers, the overexploitation of the aquifers for irrigation purposes and the intense urbanization which lacks the necessary infrastructure. In Erasinos Basin located at the Eastern Attica, which is heavily influenced by the consequences of intense agriculture and urbanization, a hydrogeological study took place including sampling, chemical analysis of the groundwater from springs, wells and boreholes, which exploit the aquifers of the Neogene formations and the karstified carbonates of the bedrock for irrigation purposes. The aim of this study is the investigation of the characteristics and the differentiation of groundwater quality, the degradation rate, the spatial distribution of the contaminants and finally, the suitability of groundwater for a number of purposes. Samples from 55 points were collected and used for the determination of main elem...
Bulletin of the Geological Society of Greece, 2020
This article deals with the hydrochemistry of coastal aquifers of the Oropos plain, Attica, Greec... more This article deals with the hydrochemistry of coastal aquifers of the Oropos plain, Attica, Greece. It is the first study which presents hydrochemical data of the Oropos plain groundwater. Groundwater samples from 34 wells were collected and analyzed for major and heavy metal constituents. Groundwater was differentiated between the Pleistocene confined aquifer and the group of the Holocene, the Miocene and the Mesozoic aquifers based on the electrical conductivity (EC) values and the chlorides content. Groundwater in the Pleistocene sediments presented EC values ranging between 766 and 971 μ S/cm and chlorides between 95-163mg/l. The group of the rest aquifers presented EC values up to 3770 μ S/cm and chlorides up to 993mg/l. The Pleistocene aquifer seems to be protected from seawater intrusion, although, it is located adjacent to the shoreline. In addition, most of the heavy metal concentration exceeded the EU limits. Cd, Fe, Pb, Ni have been determined at 82, 2500, 817, 217 μ g/li...
Bulletin of the Geological Society of Greece, 2020
The coastal karst system of Evia Island is developed due to the extended presence of carbonate fo... more The coastal karst system of Evia Island is developed due to the extended presence of carbonate formations, discharges into the sea either at the coastal zone or via submarine springs, having a direct relation to the tectonic system of the area. Thermal infrared remote sensing has been proved its capability in monitoring thermal differentiations of coastal water plumes. This work aims to locate the freshwater outflows through remote sensing and specific with the use of Landsat’s 8 thermal images and to reveal how the lineaments of the area control this karstification process. L8 contains two thermal bands (Band 10, high gain and Band 11, low gain) with resolution 30m which record the scattering of infrared radiation from the sea surface. Spectral Band 10 was selected due to the high gain characteristics which provide more suitable radiometric resolution (sensitivity). Finally, combing thermal images with geological maps, sea surface temperature (SST) maps have been created.
Bulletin of the Geological Society of Greece, 2007
Farsala Basin presents a remarkable geothermal interest. Areas exhibiting geothermal potential ar... more Farsala Basin presents a remarkable geothermal interest. Areas exhibiting geothermal potential are directly related to faulted zones, represented mainly by cross-faulted systems of E-W, NW-SE and NNE-SSW direction. Thermal waters occur in the areas of Ampelia and Krini in boreholes of 420 m depth. Their temperature ranges between 20,5° and 39,1° C. Thermal waters originate from meteoric waters, which have been infiltrated and heated in great depths, moved towards the surface through faults and hosted in the aquifers of coarse - grained formations find in the area. Their chemical composition is controlled by their contact with the volcanic parts (pillow lavas) of the ophiolithic series. They show alkaline character and low salts concentration. Waters of Ampelia region, which belong to Na-HCO^ type, exhibit temperatures from 27,9° to 39,1° C and low salt concentrations (405- 607 mg/l TDS). On the contrary, waters of Krini area present lower temperatures (20,5° -26,2° C) and higher sal...
Bulletin of the Geological Society of Greece, 2017
The study of the Kato Olympos karst system, based on the implementation of tracer tests and hydro... more The study of the Kato Olympos karst system, based on the implementation of tracer tests and hydrochemical analyses, is aimed at the investigation of surface-groundwater interaction, the delineation of the catchment area and the detection of the surface microbial source contamination of the Tempi karst springs. The study area is formed by intensively karstified carbonate rocks, metamorphic formations, Neogene sediments and Quaternary deposits. The significant karst aquifer discharges through karst springs in Tempi valley and in Pinios riverbed. The karst springs present important seasonal fluctuations in discharge rate, moderate mineralization with TDS between 562 to 630 mg/l and they belong to Ca-HCO3 water type. The inorganic pollution indicators, such as Na+, K+, Cl- , NO3 - , NH4 +, PO4 3 , show low concentrations and do not reveal any surface influences. On the other hand, the presence of microbial parameters in karst springs proclaims the high rate of microbial contamination of...
Bulletin of the Geological Society of Greece, 2017
The geological structure of Thriassion Plain is generally complex and has been affected at differ... more The geological structure of Thriassion Plain is generally complex and has been affected at different times by many tectonic activities. The last ones are the neotectonic, which caused horsts and grabens structures. Geologic and tectonic structures have influenced the hydrogeological conditions and the groundwater flow. Hydraulic characteristics of Plio-Pleistocene deposits differ throughout their extent. In this study, pumping tests in Plio-Pleistocene deposits are represented and the hydraulic characteristics transmissivity T, storativity S and hydraulic conductivity K are assigned. Pumping tests, in 8 totally wells, were conducted in the dry period. Methods as Cooper-Jacob’s, Theis’s, Papadopoulos Cooper’s and Neuman’s and last the Recovery method, are used to assign the hydraulic characteristics. These tests highlighted the Recovery method as the most reliable. Transmissivity T: 18-279.1 m2/d, storativity S: 2.5*10-3 3*10-2and hydraulic conductivity K: 0.4-25.1 m/d. Specific capa...
Bulletin of the Geological Society of Greece, 2017
This study refers to hydrogeological conditions that dominate in the closed basin of Vagia of Vio... more This study refers to hydrogeological conditions that dominate in the closed basin of Vagia of Viotia with emphasis on groundwater quality. It highlights the environmental problem of the region, associated with floods, phenomenon which occurs every year and lasts throughout the wet season. This, results in flushing undesirable substances from the territories of intensely cultivated area and the penetration into the groundwater of Neogene- Quaternary and carbonates aquifers. Qualitative charge of groundwater is reflected in the high concentrations of the ions Na+:22,2-133,4 mg/l, K+:0,3-12,0mg/l, SO4 2-:2,1-68,9mg/l, Cl-:24,8-241,1mg/l, NO3-:13,6-67,0mg/l, NH4 +:0,01-1,75mg/l, PO43-:0,03-0,94mg/l as well as the strong presence of heavy metals (Fe, Mn, Zn, Ni, Co, Cu and Cr). Qualitative charge of groundwater is attributed to natural (geogenic) and anthropogenic factors.
Bulletin of the Geological Society of Greece, 2017
In this study the hydrogeological and hydrochemical characteristics of Thriasion Plain are presen... more In this study the hydrogeological and hydrochemical characteristics of Thriasion Plain are presented focusing mainly on the presence of heavy metals in the alluvial aquifer. Two main aquifer systems exist in the study area: a) the karst aquifer hosted in the karstified carbonate formations, which structure the bedrock and the margins of the alluvial basin and b) the phreatic aquifer within the Quaternary deposits of the Thriasion Plain. Coastal and submarine groundwater discharges show the direct connection of the aquifers with the sea causing intense salinization in both aquifers. The phreatic aquifer is characterized by high levels of TDS (483 – 13,067 mg/l) and correspondingly high degree of hardness (15.7 to 165.7 odH). High concentrations of Na+, Cl-, SO4 2-, NO3 -, NH4 + and PO4 3- reflect the diverse anthropogenic influences on the aquifer. The strong presence of heavy metals, Cd, Cu, Fe, Mn, Ni, Pb, Sr and Zn has been determined in the most of the samples. Their origin is as...
Environmental Monitoring and Assessment, 2016
Groundwater has been considered as an important source of water supply due to its relatively low ... more Groundwater has been considered as an important source of water supply due to its relatively low susceptibility to pollution in comparison to surface water, and its large storage capacity. For most people in the European Union (EU), access to clean water in abundant quantities is taken for granted. It is not realized, however, that many human activities (diffuse pollution from agricultural sources) put a burden on water quality and quantity. The objectives of this paper are to document and evaluate regional trends and occurrences of nitrate in the groundwater of agricultural watersheds in Central Greece. A land use survey and water quality survey was performed in 2004 and ground water samples from various wells were collected in the time interval April - June and analysed in laboratory. The pH of the samples was measured by a pH electronic meter with a sensor probe. For the analyses in the laboratory in nitrate (NO3 - ) and in NO3-N, was used method 8039 (Procedure Code N5) or Cadmi...
I. Papanikolaou (1,2), G. Migiros (1), G. Stamatis (1), and G. Yoxas (3) (1) Laboratory of Minera... more I. Papanikolaou (1,2), G. Migiros (1), G. Stamatis (1), and G. Yoxas (3) (1) Laboratory of Mineralogy & Geology, Department of Geological Sciences and Atmospheric Environment, Agricultural University of Athens, 75 Iera Odos Str., 118 55 Athens - GR (bagm@aua.gr) , (2) Benfield-UCL ...
Zeitschrift für Geomorphologie, Supplementary Issues, 2010
Fissured Rocks and Water Reservoirs in Eastern Thessaly Mountain Range, Greece (Olympus, Ossa, Maurovouni and Pelion): The Role of Tectonic …
I. Papanikolaou (1,2), G. Migiros (1), G. Stamatis (1), and G. Yoxas (3) (1) Laboratory of Minera... more I. Papanikolaou (1,2), G. Migiros (1), G. Stamatis (1), and G. Yoxas (3) (1) Laboratory of Mineralogy & Geology, Department of Geological Sciences and Atmospheric Environment, Agricultural University of Athens, 75 Iera Odos Str., 118 55 Athens - GR (bagm@aua.gr) , (2) Benfield-UCL ...
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Papers by Georgios Stamatis