scholarly journals APPLICATION OF TRECER METHODS AND HYDROCHEMICAL ANALYSIS ON THE KARST SYSTEM OF Ν . OSSA MOUNTAIN/NE -THESSALY

2004 ◽  
Vol 36 (4) ◽  
pp. 2067
Author(s):  
Γ. Σταμάτης ◽  
E. Ζαγγανά
Keyword(s):  
Groundwater Flow ◽  
Anthropogenic Impacts ◽  
Karst Aquifer ◽  
Tracer Tests ◽  
Organic Contamination ◽  
Surface Loading ◽  
The North ◽  
North Part ◽  
Tracer Methods ◽  
Inorganic Chemical

In this paper the hydrogeological conditions of the north part of Ossa mountain are described. The research is focused on the karstic aquifer and the springs of its organic contamination are checked. Hydrochemical methods and tracer methods with NaCI and Uranine as tracers were applied. Regarding the inorganic chemical load, karstic waters show high quality status without any surface loading due to its dilution. Tracer tests reveal high groundwater flow velocity Va values ranging from 82 m/h to 146 m/h due to the intense karst and the existence of caves. Groundwater flow present NE direction and the discharge of karst aquifer take place in the Tempi value. The recorded contamination within the recharge area of the karstic springs is directly connected to anthropogenic impacts and incomplete water collection infrastructure. Actions for the aquifer protection must be taken the soonest possible.

scholarly journals Review: Advances in the methodology and application of tracing in karst aquifers

2021 ◽  
Vol 29 (1) ◽  
pp. 67-88
Author(s):  
Ralf Benischke
Keyword(s):  
Fluorescent Dyes ◽  
Anthropogenic Impacts ◽  
Karst Aquifer ◽  
Tracer Tests ◽  
Analytical Techniques ◽  
Transport Processes ◽  
Karst Hydrogeology ◽  
Flow Paths ◽  
Tracer Methods ◽  
Underground Flow

AbstractTracer methods have been widely used in many fields of environmental and natural sciences, and also in human health sciences. In particular, tracers are used in the study of karst hydrogeology, typically focusing on phenomena such as sinkholes, sinking rivers and large karst springs. It is known that tracers have been used since antiquity. The aim of tracer tests has been to investigate underground flow paths, transport processes and water–rock interactions, and to get an insight into the functioning of a karst aquifer. In karst hydrogeology, tracer methods are the most important investigation tools beside conventional hydrological methods. In early times, tracer methods were applied only to investigate underground flow-paths. Later they were also used to elucidate transport processes associated with water flow, and today they are often the basis, together with detailed hydrological information, of groundwater protection investigations and aquifer modelling. Many substances (spores, microspheres, bacteriophages, salt tracers, fluorescent dyes, radioactive substances) have been investigated for their properties and potential usage in environmental investigations, in particular the often unknown and inaccessible underground systems of karst areas. A great number of analytical techniques is available. This includes instrumentation for laboratory applications and direct online, on-site or in-situ field measurements. Modern instruments have a high capability for data acquisition, storage and transmission in short intervals, as a basis for quantitative evaluation and modelling. This enables research on the hydrological and hydrochemical dynamics of aquifers and their response to different natural or anthropogenic impacts.

scholarly journals Combining implicit geological modeling, field surveys, and hydrogeological modeling to describe groundwater flow in a karst aquifer

2020 ◽  
Vol 28 (8) ◽  
pp. 2779-2802 ◽  
Author(s):  
Fernando M. D’Affonseca ◽  
Michael Finkel ◽  
Olaf A. Cirpka
Keyword(s):  
Groundwater Flow ◽  
Karst Aquifer ◽  
Three Dimensional ◽  
Tracer Tests ◽  
Spring Discharge ◽  
Geological Modeling ◽  
Hydrogeological Model ◽  
Geological Interpretation ◽  
Elevation Data ◽  
Contact Data

AbstractIn three-dimensional (3-D) implicit geological modeling, the bounding surfaces between geological units are automatically constructed from lithological contact data (position and orientation) and the location and orientation of potential faults. This approach was applied to conceptualize a karst aquifer in the Middle Triassic Muschelkalk Formation in southwest Germany, using digital elevation data, geological maps, borehole logs, and geological interpretation. Dip and strike measurements as well as soil-gas surveys of mantel-borne CO2 were conducted to verify the existence of an unmapped fault. Implicit geological modeling allowed the straightforward assessment of the geological framework and rapid updates with incoming data. Simultaneous 3-D visualizations of the sedimentary units, tectonic features, hydraulic heads, and tracer tests provided insights into the karst-system hydraulics and helped guide the formulation of the conceptual hydrogeological model. The 3-D geological model was automatically translated into a numerical single-continuum steady-state groundwater model that was calibrated to match measured hydraulic heads, spring discharge rates, and flow directions observed in tracer tests. This was possible only by introducing discrete karst conduits, which were implemented as high-conductivity features in the numerical model. The numerical groundwater flow model was applied to initially assess the risk from limestone quarrying to local water supply wells with the help of particle tracking.

scholarly journals Groundwater Nitrate Pollution Sources Assessment for Contaminated Wellfield

Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 255
Author(s):  
Marko Šrajbek ◽  
Lado Kranjčević ◽  
Ivan Kovač ◽  
Ranko Biondić
Keyword(s):  
Groundwater Flow ◽  
Flow Model ◽  
Nitrate Concentration ◽  
Nitrate Pollution ◽  
Point Sources ◽  
Groundwater Flow Model ◽  
The North ◽  
Influence Area ◽  
North Part ◽  
Narrow Area

Nitrates are one of the most common groundwater contaminants and they come from different sources. The paper presents a study of groundwater quality at Varaždin wellfield in the north part of Croatia. The nitrate concentration at this location has been above the maximum allowed concentration for several decades, which has made the opening of new wellfields costly. Based on the previously developed groundwater flow model, a model that covers the narrow area of the wellfield is developed. The influential zone of the observed wellfield in working conditions is determined. Based on the developed model, the sources of nitrate pollution are located, which can be generally divided into non-point and point sources. Considering the time of groundwater retention in the horizontal flow, it is concluded that the water protection zones are marked following the applicable ordinance. Based on the developed groundwater flow model at the observed wellfield, a simulation of nitrate pollution propagation by advection and dispersion processes is performed. The simulation results point out the location of the poultry landfill as the largest source of nitrate pollution. However, poultry farms, which are located in the influence area of the wellfield, also contribute significantly to the nitrate concentration at the wellfield.

scholarly journals Vulnerability mapping of karst springs and its application for the delineation of protection zones (Mecsek Karst, Hungary)

2021 ◽  
Vol 50 (2-3) ◽  
Author(s):  
Éva Farics ◽  
Amadé Halász ◽  
Szabolcs Czigány ◽  
Ervin Pirkhoffer
Keyword(s):  
Human Activities ◽  
Anthropogenic Impacts ◽  
Karst Aquifer ◽  
Tracer Tests ◽  
Vulnerability Mapping ◽  
Anthropogenic Factors ◽  
Protection Zones ◽  
Risk Zonation ◽  
Vulnerability Maps ◽  
Risk Maps

Over the past decade or two, vulnerability mapping become a useful tool to determine the sensitivity of karst aquifers and allows the analysis of karstic aquifers affected by human activities. The Tettye Catchment, one of the eight catchments of the Mecsek Karst aquifer (SW Hungary), supplies drinking water for Pécs, the fifth most populous city in Hungary. However, due to its partly urbanized character and heterogeneous karstic features, this catchment is highly sensitive to anthropogenic impacts. In this study we aimed to generate resource vulnerability maps and risk maps to assess the role of physical and anthropogenic factors on groundwater vulnerability in the Mecsek Karst. Two formerly validated methods were used, the COP (Concentration, Overlaying layers and Precipitation) and SA (Slovene Approach) methods. The resource vulnerability maps, validated by former tracer tests, were combined with the hazard map obtained from the COST action 620 and EU Water Directive to generate risk maps. Tracer-based transit times were commonly less than 20 days in the majority of the areas of extreme vulnerability. During the current study, a new protocol has been elaborated for the delineation of the protection zones of karstic aquifers. Comparing the two methods, the SA performed better in terms of intrinsic vulnerability mapping, as it had a higher spatial resolution and was more detailed than the COP map and had a more sophisticated vulnerability indexing. In addition, high spatial correlation was revealed between the transit time maps and the SA map. Reassessed risk zonation, with appropriate legal consequences, likely minimizes undesired human activities within the zone of protection, hence maintaining water quality that complies with the protection acts

scholarly journals Transboundary geophysical mapping of geological elements and salinity distribution critical for the assessment of future sea water intrusion in response to sea level rise

2012 ◽  
Vol 16 (7) ◽  
pp. 1845-1862 ◽  
Author(s):  
F. Jørgensen ◽  
W. Scheer ◽  
S. Thomsen ◽  
T. O. Sonnenborg ◽  
K. Hinsby ◽  
...  
Keyword(s):  
Groundwater Flow ◽  
Sea Level Rise ◽  
Sea Level ◽  
Preferential Flow ◽  
Sea Water ◽  
Saline Water ◽  
Seismic Survey ◽  
Salinity Distribution ◽  
Geological Structures ◽  
The North

Abstract. Geophysical techniques are increasingly being used as tools for characterising the subsurface, and they are generally required to develop subsurface models that properly delineate the distribution of aquifers and aquitards, salt/freshwater interfaces, and geological structures that affect groundwater flow. In a study area covering 730 km2 across the border between Germany and Denmark, a combination of an airborne electromagnetic survey (performed with the SkyTEM system), a high-resolution seismic survey and borehole logging has been used in an integrated mapping of important geological, physical and chemical features of the subsurface. The spacing between flight lines is 200–250 m which gives a total of about 3200 line km. About 38 km of seismic lines have been collected. Faults bordering a graben structure, buried tunnel valleys, glaciotectonic thrust complexes, marine clay units, and sand aquifers are all examples of geological structures mapped by the geophysical data that control groundwater flow and to some extent hydrochemistry. Additionally, the data provide an excellent picture of the salinity distribution in the area and thus provide important information on the salt/freshwater boundary and the chemical status of groundwater. Although the westernmost part of the study area along the North Sea coast is saturated with saline water and the TEM data therefore are strongly influenced by the increased electrical conductivity there, buried valleys and other geological elements are still revealed. The mapped salinity distribution indicates preferential flow paths through and along specific geological structures within the area. The effects of a future sea level rise on the groundwater system and groundwater chemistry are discussed with special emphasis on the importance of knowing the existence, distribution and geometry of the mapped geological elements, and their control on the groundwater salinity distribution is assessed.

Oscillations of the Black Sea sea level in the north part of the coast

1999 ◽  
Vol 10 (2) ◽  
pp. 123-130
Author(s):  
Yu. I. Goryachkin ◽  
V. A. Ivanov ◽  
Yu. A. Stepanyants
Keyword(s):  
Sea Level ◽  
Black Sea ◽  
The Black Sea ◽  
The North ◽  
North Part

Flow pattern and residence time of conduit flow and diffuse flow in calcareous sandstones (Bohemian Cretaceous Basin, Czech Republic)

2021 ◽  
Author(s):  
Iva Kůrková ◽  
Jiří Bruthans
Keyword(s):  
Czech Republic ◽  
Groundwater Flow ◽  
Residence Time ◽  
Dispersion Model ◽  
Tracer Tests ◽  
Water Levels ◽  
Northwestern Part ◽  
Residence Times ◽  
Karst Springs ◽  
Bohemian Cretaceous Basin

<p>Localities containing karst features were studied in the northwestern part of Bohemian Cretaceous Basin. Namely Turnov area in facies transition between coarse-delta sandstones and marlstones (Jizera Formation, Turonian) and Miskovice area in limestones and sandy limestones - sandstones (Peruc-Korycany Formation, Cenomanian). Evolution of karst conduits is discussed elsewhere (Kůrková et al. 2019).</p><p>In both localities, disappearing streams, caves and karst springs with maximum discharge up to 100 L/s were documented. Geology and hydrogeology of this area was studied from many points of view to describe formation of karst conduits and characterize groundwater flow. Tracer tests were performed using NaCl and Na-fluoresceine between sinkholes and springs under various flow rates to evaluate residence times of water in conduits and to describe geometry of conduits. Breatkthrough curves of tracer tests were evaluated by means of Qtracer2 program (Field 2002). Groundwater flow velocity in channels starts at 0.6 km/day during low water levels up to 15 km/day during maximum water levels, the velocity increases logarithmically as a function of discharge. Similar karst conduits probably occur in other parts of Bohemian Cretaceous Basin where lot of large springs can be found.</p><p>Mean residence time of difussed flow based on tritium, CFC and SF<sub>6</sub> sampled at karst springs is 20 years for 75% of water and 100 years for remaining 25%, based on binary mixing dispersion model. This shows that most of the water drained by karst conduits is infiltrated through the soil and fractured environment with relatively high residence time. Residence times in different types of wells and springs were also measured in whole north-western part of Bohemian Cretaceous Basin. Results indicate long residence times in semi-stagnant zones represented by monitoring wells and short residence times in preferential zones represented by springs and water-supply wells.</p><p> </p><p>Research was funded by the Czech Science Foundation (GA CR No. 19-14082S), Czech Geological Survey – internal project 310250</p><p> </p><p>Field M. (2002): The QTRACER2 program for Tracer Breakthrough Curve Analysis for Tracer Tests in Karstic Aquifers and Other hydrologic Systems. – U.S. Environmental protection agency hypertext multimedia publication in the Internet at http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=54930.</p><p>Kůrková I., Bruthans J., Balák F., Slavík M., Schweigstillová J., Bruthansová J., Mikuš P., Grundloch J. (2019): Factors controlling evolution of karst conduits in sandy limestone and calcareous sandstone (Turnov area, Czech Republic). Journal of Hydrology: 574: 1062-1073</p>

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