Assessing flow paths in a karst aquifer based on multiple dye tracing tests using stochastic simulation and the MODFLOW-CFP code

2017 ◽  
Vol 25 (6) ◽  
pp. 1679-1702 ◽  
Author(s):  
Amin Assari ◽  
Zargham Mohammadi
Keyword(s):  
Stochastic Simulation ◽  
Karst Aquifer ◽  
Flow Paths ◽  
Dye Tracing

scholarly journals FACTORS INFLUENCING KARST AQUIFER RECHARGE AS EVIDENCED THROUGH VADOSE DYE TRACING

2018 ◽  
Author(s):  
Amaël Poulain ◽  
◽  
Arnaud Watlet ◽  
Gaëtan Rochez ◽  
Olivier Kaufmann ◽  
...  
Keyword(s):  
Karst Aquifer ◽  
Aquifer Recharge ◽  
Dye Tracing ◽  
Factors Influencing

Hydrostratigraphy of the Malmani Subgroup dolomites within the northeastern escarpment (Limpopo and Mpumalanga, South Africa)

2019 ◽  
Vol 122 (3) ◽  
pp. 283-298
Author(s):  
S.S.E. Mndaweni ◽  
S. Naicker ◽  
D. Blake
Keyword(s):  
Surface Water ◽  
Groundwater Flow ◽  
Water Discharge ◽  
Karst Aquifer ◽  
Groundwater Potential ◽  
Flow Paths ◽  
Discharge Rates ◽  
Management Area ◽  
Transvaal Supergroup ◽  
High Degree

Abstract The Late Archaean to Early Proterozoic Malmani Subgroup comprises of dolomites and limestones forming part of the Chuniespoort Group within the Transvaal Supergroup, outcropping as an arc structure east of the Pretoria Group along the Limpopo and Mpumalanga escarpment. These rocks form a fractured karst aquifer in the area and have a high degree of heterogeneity and anisotropy. The aquifers are unconfined to semi-confined, with compartmentalisation by dolerite dykes being a possible effect (if the dykes are large and extensive enough) due to the dykes acting as aquitards or barriers to groundwater flow. The contact zones between the dolomite formations and dolerite dykes are usually fractured however, and along with any other faults and fractures result in preferential dolomite dissolution and the development of groundwater flow paths in the area. Borehole yields ranges between 2 to 5 l/s and potentially >10 l/s per borehole in the vicinity of large regional fractures or dolerite intrusions. Groundwater from the Malmani Subgroup generally meets the drinking water quality standards for major constituents and it is of Mg-Ca-HCO3 nature. Groundwater development within this particular hydrostratigraphy is linked to potential well field target zones that take cognisance of various surface water-groundwater interaction affecting surface water discharge rates as well as groundwater over-abstraction concerns. Preliminary results have indicated that given a groundwater potential of 44 hm3/a, the aquifer will be able to support abstractions of up to 29 hm3/a if systematically developed adaptively and could be used and managed conjunctively with surface water to alleviate the pressure on the already stressed Olifants Water Management Area.

scholarly journals Spatially resolved information on karst conduit flow from in-cave dye tracing

2014 ◽  
Vol 18 (2) ◽  
pp. 435-445 ◽  
Author(s):  
U. Lauber ◽  
W. Ufrecht ◽  
N. Goldscheider
Keyword(s):  
Land Surface ◽  
Karst Aquifer ◽  
Tracer Tests ◽  
Breakthrough Curves ◽  
Transport Parameters ◽  
Mean Flow ◽  
Dye Tracing ◽  
Flow And Transport ◽  
Spatially Resolved ◽  
Order Of Magnitude

Abstract. Artificial tracers are powerful tools for investigating karst systems. Tracers are commonly injected into sinking streams or dolines, while springs serve as monitoring sites. The obtained flow and transport parameters represent mixed information from the vadose, epiphreatic and phreatic zones (that is, the aquifer remains a black box). Accessible active caves constitute valuable but underexploited natural laboratories to gain detailed insights into the hydrologic functioning of the aquifer. Two multi-tracer tests in the catchment of a major karst spring (Blautopf, Germany) with injections and monitoring in two associated water caves aimed at obtaining spatially and temporally resolved information on groundwater flow in different compartments of the system. Two tracers were injected into the caves to characterize the hydraulic connections between them and with the spring. Two injections at the land surface, far from the spring, aimed at resolving the aquifer's internal drainage structure. Tracer breakthrough curves were monitored by field fluorimeters in caves and at the spring. Results demonstrate the dendritic drainage structure of the aquifer. It was possible to obtain relevant flow and transport parameters for different sections of this system. The highest mean flow velocities (275 m h−1) were observed in the near-spring epiphreatic section (open-channel flow), while velocities in the phreatic zone (pressurized flow) were one order of magnitude lower. Determined conduit water volumes confirm results of water balances and hydrograph analyses. In conclusion, experiments and monitoring in caves can deliver spatially resolved information on karst aquifer heterogeneity and dynamics that cannot be obtained by traditional investigative methods.

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 Spatially resolved information on karst conduit flow from in-cave dye-tracing

2013 ◽  
Vol 10 (9) ◽  
pp. 11311-11335 ◽  
Author(s):  
U. Lauber ◽  
W. Ufrecht ◽  
N. Goldscheider
Keyword(s):  
Land Surface ◽  
Karst Aquifer ◽  
Tracer Tests ◽  
Breakthrough Curves ◽  
Transport Parameters ◽  
Mean Flow ◽  
Dye Tracing ◽  
Flow And Transport ◽  
Spatially Resolved ◽  
Order Of Magnitude

Abstract. Artificial tracers are powerful tools to investigate karst systems. Tracers are commonly injected into sinking streams or dolines, while springs serve as monitoring sites. The obtained flow and transport parameters represent mixed information from the vadose, epiphreatic and phreatic zones, i.e., the aquifer remains a black box. Accessible active caves constitute valuable but underexploited natural laboratories to gain detailed insights into the hydrologic functioning of the aquifer. Two multi-tracer tests in the catchment of a major karst spring (Blautopf, Germany) with injections and monitoring in two associated water caves aimed at obtaining spatially and temporally resolved information on groundwater flow in different compartments of the system. Two tracers were injected in the caves to characterize the hydraulic connections between them and with the spring. Two injections at the land surface, far from the spring, aimed at resolving the aquifer's internal drainage structure. Tracer breakthrough curves were monitored by field fluorimeters in caves and at the spring. Results demonstrate the dendritic drainage structure of the aquifer. It was possible to obtain relevant flow and transport parameters for different sections of this system. The highest mean flow velocities (275 m h−1) were observed in the near-spring epiphreatic section (open-channel flow), while velocities in the phreatic zone (pressurized flow) were one order of magnitude lower. Determined conduit water volumes confirm results of water balances and hydrograph analyses. In conclusion, experiments and monitoring in caves can deliver spatially resolved information on karst aquifer heterogeneity and dynamics that cannot be obtained by traditional investigative methods.

scholarly journals Dye tracer and morphophysical properties to observe water flow in a Gleyic Luvisol

2011 ◽  
Vol 68 (2) ◽  
pp. 160-166 ◽  
Author(s):  
Monica Martins Silva Salvador ◽  
Sigrid Köhne ◽  
John Maximilian Köhne ◽  
Bernd Lennartz ◽  
Paulo Leonel Libardi
Keyword(s):  
Soil Properties ◽  
Water Flow ◽  
Arable Land ◽  
Great Depth ◽  
Colour Pattern ◽  
Blue Dye ◽  
Flow Paths ◽  
Dye Tracing ◽  
Surface Water Resources ◽  
Dye Tracer

The understanding of the preferential water flow and solute transport is important with regard to losses of nutrients and pesticides that affect the quality of the groundwater or surface water resources. Experiments using the brilliant blue dye tracer, a tension infiltrometer (TI) and a double square infiltrometer (DI) were carried out in the experimental field site located around 15 km southeast of the city of Rostock (North-Eastern Germany) on arable land in a Pleistocene lowland landscape where corn (Zea mays L.) and barley (Hordeum spp.) had been cultivated. One day after dye the infiltration, a pit was dug and vertical profiles were prepared in the TI and DI sites to assess the dye pathways in the subsoil of a Gleyic Luvisol. We wanted to examine if the mottled red and white (bleached) colour-pattern of the Gleyic Luvisol subsoil resulting from temporally stagnant water could be related to flow paths as visualized by dye tracing and if the soil colour could be related to other physical soil properties. Biogenic soil structures were the main transport routes conducting water and solutes into great depth in short time. These pathways had lower bulk density and less cone resistance than the adjacent red or white (bleached) areas of the Gleyic Luvisol subsoil. The red areas were involved in transport because their water contents increased after as compared to before infiltration. However, the measured physical soil properties did not differ between white and red areas. We assume that red areas participate in transport at least by imbibing water from the adjacent biogenic flow paths.

Identifying distributions of response times in karst aquifers

2021 ◽  
Author(s):  
Fulvio Boano ◽  
Alberto Viglione ◽  
Bartolomeo Vigna
Keyword(s):  
Response Time ◽  
Response Times ◽  
Karst Aquifer ◽  
Response Time Distribution ◽  
Spring Discharge ◽  
Aquifer Recharge ◽  
Flow Paths ◽  
Ill Posed ◽  
Response Time Distributions ◽  
Different Response

<p>In karst catchments, aquifer recharge occurs through a composite mosaic of subsurface flow paths. Precipitation infiltrates in the subsurface and flows along a complex network of fractures – that are characterized by different sizes and degrees of saturation –  before eventually reaching the catchment outlet. The discharge of a karst spring is the result of the contributions of these flow paths, that may differ widely in terms of lengths, velocities, and travel times. Monitoring the spring discharge can thus provide information about flow within the aquifer. In particular, the spring discharge signal can be interpreted as the lagged response of the aquifer to precipitation inputs over the catchment, with the aquifer being characterized by a distribution of response times that relates input (precipitation) to output (discharge). Identifying these response times is not a trivial task as the input-output problem is often mathematically ill-posed, which leads to amplification of the errors and may prevent finding a physically meaningful solution.</p><p>In this work we propose a method to evaluate the distribution of response times of a karst aquifer. The method, that was originally developed to deal with ill-posed problems in geostatistical applications, relies on a probabilistic description of precipitation inputs and discharge outputs, and it provides an estimate of the response time distribution and of its uncertainty. The method is here tested through the application to two datasets collected in two cave systems in Northern Italy (the Bossea system and the Vene/Fuse system) with different hydrogeological properties. The results demonstrate that the method successfully identifies different response time distributions that reflect the differences in aquifer characteristics of the two systems. Furthermore, differences among response time distributions relative to different precipitation events in each system provide valuable insights on seasonal variations in aquifer recharge and fracture saturation. The method can hence be applied as a tool for the indirect investigation of karst systems.</p>

Proper flow paths in vertex-weighted communication nets

1968 ◽  
Vol 115 (3) ◽  
pp. 376 ◽  
Author(s):  
B.R. Myers ◽  
B.R. Myers ◽  
E.A. Davila
Keyword(s):  
Flow Paths
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