scholarly journals Enhanced Characterization of the Krania–Elassona Structure and Functioning Allogenic Karst Aquifer in Central Greece

Geosciences ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 15 ◽  
Author(s):  
Antonios Manakos ◽  
Maria Ntona ◽  
Nerantzis Kazakis ◽  
Konstantinos Chalikakis

The present study highlights the importance of geological, hydrogeological, and hydrogeochemical characterization of a karst aquifer in building a conceptual model of the system. The karst system of Krania–Elassona in central Greece was chosen for this application. Hydrogeological research included geological mapping and hydrogeological analysis. Additionally, hydrochemical analysis of water samples was performed in boreholes, rivers, and the system’s main spring. The Krania–Elassona aquifer consists of three horizons of marbles and is characterized by mature karstification. The karst aquifer is characterized by allogenic recharge mainly from the River Deskatis that accounts for up to 92% of the total flow. Groundwater and spring water are generally characterized as good quality and are suitable for irrigation and domestic use. The water type of the spring water is classified as Mg-HCO3. The application of a SARIMA (Seasonal Autoregressive Integrated Moving Average Model) model verified the conceptual model and successfully simulated spring discharge for a two-year period. The results of this study highlight the importance of basic hydrogeological research and the initial conceptualization of karst systems in reliably assessing groundwater vulnerability and modeling.

2022 ◽  
Author(s):  
Fatemeh Geravand ◽  
Seiyed Mossa Hosseini ◽  
Mehran Maghsoudi ◽  
Mojtaba Yamani

Abstract Karst groundwater resources in the Zagros Mountains are vital for supplying of different demands in the region which need to sustainable management and protection. Quantitative and qualitative characterization of karst aquifers in this region were understudied due to lack of site-specific logging-data and speleological investigations. In this study, a state-of-the-art of the statistical methods developed to characterize karst aquifer based on analyses of the spring recession hydrograph and spring water quality are presented. These methods including Manging’s method for classification of karst aquifers, relationships of precipitation and discharge data, groundwater quality index (GQI), hydrochemical diagrams (Piper, Durov and Gibbs), and Saturation index (SI), Chloro-Alkaline indices (CAI). 42 major karst springs mainly located in folded part of Zagros region (western Iran) are selected for application of the reviewed methods. Results indicated that the saturated zone exerts almost main control over the discharge of 76% of the studied springs. The base-flow contributes as between 80.0% to 100% of total water storage in the study aquifers. 78.5% of the studied aquifers have a high karstification degree. An insignificant lag-time is observed between the precipitation on the karst basin and spring discharge. The hydrochemical diagrams show that the waters are dominated by HCO3 and Ca and the majority of the waters are alkaline, with originate from silicate minerals weathering. Such repeatable methods adopted in this study can provide crucial information of the karst aquifers, especially those suffer scarcity of aquifer hydrodynamic data.


Author(s):  
Giuseppe Sappa ◽  
Flavia Ferranti ◽  
Francesco Maria De Filippi

The Upper Aniene River basin is part of a large karst aquifer, which interacts with the river, and represents the most important water resource in the southeast part of Latium Region, Central Italy, used for drinking, agriculture and hydroelectric supplies. This work provides hydrogeochemical data and their interpretations for 1 spring and 2 cross section of Aniene River, monitored from July 2014 to December 2015, in the Upper Valley of Aniene River, to identify flow paths and hydrogeochemical processes governing groundwater-surface water interactions in this region. These activities deal with the Environmental Monitoring Plan made for the catchment work project of the Pertuso Spring, in the Upper Valley of Aniene River, which is going to be exploited to supply an important drinking water network in the South part of Rome district. Discharge measurements and hydrogeochemical data were analyzed to develop a conceptual model of aquifer-river interaction, with the aim of achieving proper management and protection of this important hydrogeological system. All groundwater samples are characterized as Ca-HCO3 type. Geochemical modeling and saturation index computation of the water samples show that groundwater and surface water chemistry in the study area was evolved through the interaction with carbonate minerals. All groundwater samples were undersaturated with respect to calcite and dolomite, however some of the Aniene River samples were saturated with respect to dolomite. The analysis of Mg2+/Ca2+ ratios indicates that the dissolution of carbonate minerals is important for groundwater and surface water chemistry, depending on the hydrological processes, which control the groundwater residence time and chemical equilibria in the aquifer.


2020 ◽  
Vol 28 (7) ◽  
pp. 2613-2629 ◽  
Author(s):  
Isabel Paiva ◽  
Lúcio Cunha

Abstract A study on the complex processes of hydrogeological transformation of recharge into discharge within a karst system is described. Given the absence of boreholes or points of direct observation, the applied methodology is based on study of the natural response of the main outlet of the karst aquifer, considered here as a black-box. Time series analysis and recession curve analysis are applied to daily time series of rainfall as input, and spring discharge as the output of the aquifer. Daily variations of temperature and electrical conductivity of spring water are considered as well. The present study, an integrated research endeavor, is the first quantitative approach toward understanding the hydrogeological functioning of a large and not-well-known karst aquifer and improving existing knowledge about its internal physical characteristics. The case study is the Degracias-Sicó karst aquifer, in Portugal’s central-western region, which is relatively unknown from the hydrogeological perspective. The response of the karst aquifer’s main spring shows an important component of quick flow after heavy rainfall events and then a very slow recession. This bimodal behavior is proof of the significant spatial complexity and heterogeneity of the karst aquifer, marked by the presence of a conduit-dominated flow throughout a connected conduit network system and the dominance of base flow that confirms the aquifer’s large storage capacity. The results also demonstrate a significant component of delayed flow.


Geosciences ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 36
Author(s):  
Vayia Xanthopoulou ◽  
Ioannis Iliopoulos ◽  
Ioannis Liritzis

The present study deals with the characterization of a ceramic assemblage from the Late Mycenaean (Late Helladic III) settlement of Kastrouli, at Desfina near Delphi, Central Greece using various analytical techniques. Kastrouli is located in a strategic position supervising the Mesokampos plateau and the entire peninsula and is related to other nearby coeval settlements. In total 40 ceramic sherds and 8 clay raw materials were analyzed through mineralogical, petrographic and microstructural techniques. Experimental briquettes (DS) made from clayey raw materials collected in the vicinity of Kastrouli, were fired under temperatures (900 and 1050 °C) in oxidizing conditions for comparison with the ancient ceramics. The petrographic analysis performed on thin sections prepared from the sherds has permitted the identification of six main fabric groups and a couple of loners. The aplastic inclusions recognized in all fabric groups but one confirmed the local provenance since they are related to the local geology. Fresh fractures of representative sherds were further examined under a scanning electron microscope (SEM/EDS) helping us to classify them into calcareous (CaO > 6%) and non-calcareous (CaO < 6%) samples (low and high calcium was noted in earlier pXRF data). Here, the ceramic sherds with broad calcium separation are explored on a one-to-one comparison on the basis of detailed mineralogical microstructure. Moreover, their microstructure was studied, aiming to estimate their vitrification stage. The mineralogy of all studied samples was determined by means of X-ray powder diffraction (XRPD), permitting us to test the validity of the firing temperatures revealed by the SEM analysis. The results obtained through the various analytical techniques employed are jointly assessed in order to reveal potters’ technological choices.


2002 ◽  
Vol 45 (3) ◽  
pp. 25-34 ◽  
Author(s):  
J. Vollertsen ◽  
T. Hvitved-Jacobsen

Characterization of wastewater for simulation of in-sewer transformations can be carried out by interpretation of oxygen uptake rate measurements in combination with a conceptual model of the microbial transformations involved. This interpretation can be done by iterative procedures by solving the differential equations constituting the model or by the application of a more “manual” method – the latter being the topic of this paper. Examples where different wastewaters are characterized illustrate the method.


2021 ◽  
Author(s):  
Miguel Moreno-Gómez ◽  
Carolina Martínez-Salvador ◽  
Rudolf Lied ◽  
Catalin Stefan ◽  
Julia Pacheco

Abstract. Groundwater vulnerability maps are important decision support tools for water resources protection against pollution and helpful to minimize environmental damage. However, these tools carry a high subjectivity along the multiple steps taken for the development of such maps. Additionally, the theoretical models on which they are based do not consider important parameters such as pollutant concentration or pollutant residence time in a given section of the aquifer, solely focusing the analysis on a theoretical travel time from a release point towards a target. In this work, an integrated methodology for the evaluation of potential (intrinsic) and actual vulnerability is presented. This integrated method, named IKAV, was developed after the analysis of several study cases and the application of multiple intrinsic groundwater vulnerability methods in a selected study area. Also, a solute transport model served as the basis to define additional parameters for vulnerability analysis for areas severely affected by anthropogenic practices. A defined workflow and several criteria for parameters and attributes selection, rating and weighting assignment, and vulnerability classification are presented. The first application of the IKAV method was carried out in the Yucatan karst, demonstrating to be a reliable method for vulnerability estimation. Results demonstrated the scope of the IKAV method to highlight important regional conditions, minimizing the subjectivity, and expanding the analysis of vulnerability.


Author(s):  
Anna Caroline Andrade Pinto ◽  
Tiago Felipe Arruda Maia

Many of the studies about mineral deposits are bringing great information to the scientific community, providing, for example, general characteristics of these deposits, possible source areas and its used in some cases as prospective tools to help in geological mapping. In this way, this study aimed to characterize the alluvial secondary deposits of columbite-tantalite that were found near vicinal 12, about 50km north/northeast of Rorainópolis city, between the BR-174 and BR-210 roads, in the state of Roraima (Brazil), bases on 4 samples that were brought by a resident of the region. To fulfill these objectives, some chemical and mineralogical methods were performed, like: magnetic separation, X-ray diffraction, X-ray fluorescence and petrographic description. The deposits of the region end up being characterized by having a large amount of Fe and Ti (mostly), containing in some places also a large concentration of Niobium and Tantalum. Not all samples have columbite-tantalite, showing that their concentration in some areas of the deposit is quite low. There are samples with less than 1% Nb and Ta and also samples with more than 20% Nb and 6% Ta concentration. These minerals were poorly transported, being identified by the degree of roundness and granulometry of the samples. A weathering cap on some minerals could also be verified. This research work turned out to be relevant, as it provides new data that add to the knowledge of the mineral potential, which has not been fully explored yet.


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