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Speleology in Kazakhstan

Shakalov on 04 Jul, 2018
Hello everyone!   I pleased to invite you to the official site of Central Asian Karstic-Speleological commission ("Kaspeko")   There, we regularly publish reports about our expeditions, articles and reports on speleotopics, lecture course for instructors, photos etc. ...

New publications on hypogene speleogenesis

Klimchouk on 26 Mar, 2012
Dear Colleagues, This is to draw your attention to several recent publications added to KarstBase, relevant to hypogenic karst/speleogenesis: Corrosion of limestone tablets in sulfidic ground-water: measurements and speleogenetic implications Galdenzi,

The deepest terrestrial animal

Klimchouk on 23 Feb, 2012
A recent publication of Spanish researchers describes the biology of Krubera Cave, including the deepest terrestrial animal ever found: Jordana, Rafael; Baquero, Enrique; Reboleira, Sofía and Sendra, Alberto. ...

Caves - landscapes without light

akop on 05 Feb, 2012
Exhibition dedicated to caves is taking place in the Vienna Natural History Museum   The exhibition at the Natural History Museum presents the surprising variety of caves and cave formations such as stalactites and various crystals. ...

Did you know?

That ground-water pumping is 1. directed or oscillatory ground-water movement, along incipient fissures in the rock, that occurs due to very small but significant relative movements of the rocks themselves, maybe as a diurnal, tidal process. it may be one of the driving mechanisms of earliest, inception, phase of speleogenesis [9]. the pumping of a water well to provide water for drinking, irrigation, and manufacturing. but may also be conducted for dewatering purposes.?

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Featured articles from Cave & Karst Science Journals
Chemistry and Karst, White, William B.
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Featured articles from other Geoscience Journals
Karst environment, Culver D.C.
Mushroom Speleothems: Stromatolites That Formed in the Absence of Phototrophs, Bontognali, Tomaso R.R.; D’Angeli Ilenia M.; Tisato, Nicola; Vasconcelos, Crisogono; Bernasconi, Stefano M.; Gonzales, Esteban R. G.; De Waele, Jo
Calculating flux to predict future cave radon concentrations, Rowberry, Matt; Marti, Xavi; Frontera, Carlos; Van De Wiel, Marco; Briestensky, Milos
Microbial mediation of complex subterranean mineral structures, Tirato, Nicola; Torriano, Stefano F.F;, Monteux, Sylvain; Sauro, Francesco; De Waele, Jo; Lavagna, Maria Luisa; D’Angeli, Ilenia Maria; Chailloux, Daniel; Renda, Michel; Eglinton, Timothy I.; Bontognali, Tomaso Renzo Rezio
Evidence of a plate-wide tectonic pressure pulse provided by extensometric monitoring in the Balkan Mountains (Bulgaria), Briestensky, Milos; Rowberry, Matt; Stemberk, Josef; Stefanov, Petar; Vozar, Jozef; Sebela, Stanka; Petro, Lubomir; Bella, Pavel; Gaal, Ludovit; Ormukov, Cholponbek;
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Your search for breakthrough curves (Keyword) returned 24 results for the whole karstbase:
Showing 1 to 15 of 24
Predicting travel times and transport characterization in karst conduits by analyzing tracer-breakthrough curves, , Morales Tomas, De Valderrama Inigo, Uriarte Jesus A. , Antiguedad Inaki, Olazar Martin,
SummaryThis paper analyzes data obtained in 26 tracer tests carried out in 11 karstic connections following solutional conduits in karst aquifers in the Basque Country. These conduits are preferential drainage pathways in these aquifers and so they confer a marked anisotropy and high vulnerability to them. Consequently, their consideration in protection and management studies and projects is a priority.The connections studied cover a wide hydrogeological spectrum (a wide range of sizes, slopes, geomorphic and hydrologic types) and the tests have been carried out at different hydrodynamic states. It is noteworthy that they all follow a similar trend, which has allowed for the development of a statistical approximation for the treatment of the whole information.Relationships have been established involving velocity, solute time of arrival, attenuation of peak concentration and time of passage of tracer cloud. These relationships are a valuable tool for management and supporting decision-making and allow for making estimates in connections in which the information available was scarce. This information is especially useful, given that the complexity of transport in karst conduits gives way to important deviations between real data (empirical observations) and the data obtained by simple approaches based on the Fickian-type diffusion equation

The Hydrology of a Glacierised Alpine Karst Castlegaurd Mountain, Alberta, PhD Thesis, 1983, Smart, Charles Christopher

Alpine karst throughout the world has been affected by past glaciation, and yet little is known of the interactions between glacier ice and karst. This dissertation attempts to gain some understanding of the problem through the study of the Castleguard Area, Alberta, where a karst aquifer is presently overlain by temperate glacier ice.
Quantitative fluorometric tracing and hydrometric measurements generated a broad data base on aquifer behaviour. Tracer breakthrough curves were interpreted using a new systematic approach which considers an explicit set of processes likely to affect the particular tracer under the given experimental conditions. Non-linearity in aquifer behaviour and rapid groundwater velocities demonstrated the aquifer to be an extreme conduit type Conduit springs are elements in a vertical hierarchy in which the topmost springs are "overflows" and exhibit greater flow variability than their associated "underflows". A numerical model was developed to simulate a conduit aquifer. It demonstrated that pulse train and recession analysis widely accepted methods of karst aquifer investigation, could be rather misleading when applied to conduit aquifers.
Interactions between ice and groundwater were observed at two scales: regulation water appeared to feed a diffuse percolation system and supraglacial melt passed into subglacial conduits which entered open vadose shafts. Karst is unlikely to be entirely subglacial in origin because of the limited aggressiveness of subglacial waters.
The Castlegaurd karst appeared to have originated preglacially in response to the breaching of impermeable caprock. Glaciation re-ordered the landscape and produced abundant clastic debris which subsequently blocked or obstructed karst conduits. Much of the resulting karst is paragenetic and comparatively immature due to glacial disruption and slow growth rates. Geomorphic and hydrologic interactions between ice and karst depend intimately upon the relationship between the geographic zones of the glacier and the aquifer.


Structure et comportement hydraulique des aquifers karstiques, DSc thesis, 1996, Jeannin, P. Y.

This thesis aims to provide a better knowledge of karst flow systems, from a functional point of view (behaviour with time), as well as from a structural one (behaviour in space). The first part of the thesis deals with the hydrodynamic behaviour of karst systems, and the second part with the geometry of karstic networks, which is a strong conditioning factor for the hydrodynamic behaviour.
Many models have been developed in the past for describing the hydrodynamic behaviour of karst hydrogeological systems. They usually aim to provide a tool to extrapolate, in time and/or space, some characteristics of the flow fields, which can only be measured at a few points. Such models often provide a new understanding of the systems, beyond what can be observed directly in the field. Only special field measurements can verify such hypotheses based on numerical models. This is an significant part of this work. For this purpose, two experimental sites have been equipped and measured: Bure site or Milandrine, Ajoie, Switzerland, and Holloch site, Muotathal, Schwyz, Switzerland. These sites gave us this opportunity of simultaneously observe hydrodynamic parameters within the conduit network and, in drillholes, the "low permeability volumes" (LPV) surrounding the conduits.
These observations clearly show the existence of a flow circulation across the low permeability volumes. This flow may represent about 50% of the infiltrated water in the Bure test-field. The epikarst appears to play an important role into the allotment of the infiltrated waters: Part of the infiltrated water is stored at the bottom of the epikarst and slowly flows through the low permeability volumes (LPV) contributing to base flow. When infiltration is significant enough the other part of the water exceeds the storage capacity and flows quickly into the conduit network (quick flow).
For the phreatic zone, observations and models show that the following scheme is adequate to describe the flow behaviour: a network of high permeability conduits, of tow volume, leading to the spring, is surrounded by a large volume of low permeability fissured rock (LPV), which is hydraulically connected to the conduits. Due to the strong difference in hydraulic conductivity between conduits and LPV, hydraulic heads and their variations in time and space are strongly heterogeneous. This makes the use of piezometric maps in karst very questionable.
Flow in LPV can be considered as similar to flow in fractured rocks (laminar flow within joints and joints intersections). At a catchment scale, they can be effectively considered as an equivalent porous media with a hydraulic conductivity of about 10-6 to 10-7 m/s.
Flow in conduits is turbulent and loss of head has to be calculated with appropriate formulas, if wanting any quantitative results. Our observations permitted us to determine the turbulent hydraulic conductivity of some simple karst conduits (k', turbulent flow), which ranges from 0.2 to 11 m/s. Examples also show that the structure of the conduit network plays a significant role on the spatial distribution of hydraulic heads. Particularity hydraulic transmissivity of the aquifer varies with respect to hydrological conditions, because of the presence of overflow conduits located within the epiphreatic zone. This makes the relation between head and discharge not quadratic as would be expected from a (too) simple model (with only one single conduit). The model applied to the downstream part of Holloch is a good illustration of this phenomena.
The flow velocity strongly varies along the length of karst conduits, as shown by tracer experiments. Also, changes in the conduit cross-section produce changes in the (tow velocity profile. Such heterogeneous flow-field plays a significant role in the shape of the breakthrough curves of tracer experiments. It is empirically demonstrated that conduit enlargements induce retardation of the breakthrough curve. If there are several enlargements one after the other, an increase of the apparent dispersivity will result, although no diffusion with the rock matrix or immobile water is present. This produces a scale effect (increase of the apparent dispersivity with observation scale). Such observations can easily be simulated by deterministic and/or black box models.
The structure of karst conduit networks, especially within the phreatic zone, plays an important role not only on the spatial distribution of the hydraulic heads in the conduits themselves, but in the LPV as well. Study of the network geometry is therefore useful for assessing the shape of the flow systems. We further suggest that any hydrogeological study aiming to assess the major characteristics of a flow system should start with a preliminary estimation of the conduit network geometry. Theories and examples presented show that the geometry of karst conduits mainly depends on boundary conditions and the permeability field at the initial stage of the karst genesis. The most significant boundary conditions are: the geometry of the impervious boundaries, infiltration and exfiltration conditions (spring). The initial permeability field is mainly determined by discontinuities (fractures and bedding planes). Today's knowledge allows us to approximate the geometry of a karst network by studying these parameters (impervious boundaries, infiltration, exfiltration, discontinuity field). Analogs and recently developed numerical models help to qualitatively evaluate the sensitivity of the geometry to these parameters. Within the near future, new numerical tools will be developed and will help more closely to address this difficult problem. This development will only be possible if speleological networks can be sufficiently explored and used to calibrate models. Images provided by speleologists to date are and will for a long time be the only data which can adequately portray the conduit networks in karst systems. This is helpful to hydrogeologists. The reason that we present the example of the Lake Thun karst system is that it illustrates the geometry of such conduits networks. Unfortunately, these networks are three-dimensional and their visualisation on paper (2 dimensions) is very restrictive, when compared to more effective 3-D views we can create with computers. As an alternative to deterministic models of speleogenesis, fractal and/or random walk models could be employed.


Risk assessment methodology for karst aquifers .1. Estimating karst conduit-flow parameters, 1997, Field Ms, Nash Sg,
Quantitative ground-water tracing of conduit-dominated karst aquifers allows for reliable and practical interpretation of karst ground-water flow. Insights into the hydraulic geometry of the karst aquifer may be acquired that otherwise could not be obtained by such conventional methods as potentiometric-surface mapping and aquifer testing. Contamination of karst aquifers requires that a comprehensive tracer budget be performed so that karst conduit hydraulic-flow and geometric parameters be obtained. Acquisition of these parameters is necessary for estimating contaminant fate-and-transport. A FORTRAN computer program for estimating total tracer recovery from tracer-breakthrough curves is proposed as a standard method. Estimated hydraulic-flow parameters include mean residence time, mean flow velocity, longitudinal dispersivity, Peclet number, Reynolds number, and Froude number. Estimated geometric parameters include karst conduit sinuous distance, conduit volume, cross-sectional area, diameter, and hydraulic depth. These parameters may be used to (1) develop structural models of the aquifer, (2) improve aquifer resource management, (3) improve ground-water monitoring systems design, (4) improve aquifer remediation, and (5) assess contaminant fate-and-transport. A companion paper demonstrates the use of these hydraulic-flow and geometric parameters in a surface-water model for estimating contaminant fate-and-transport in a karst conduit. Two ground-water tracing studies demonstrate the utility of this program for reliable estimation of necessary karst conduit hydraulic-flow and geometric parameters

Dispersion and tailing of tracer plumes in a karstic system (Milandre, JU, Switzerland), 1997, Jeannin Py. , Marechal Jc.
A large number of tracing experiments have been carried out in a karstic aquifer in the Swiss Jura. These allow to observe the evolution of a tracer plume along the length of a karst conduit. The method of Sauty was used to make possible the comparison between all the observed breakthrough curves. The flow velocities and the dispersivities obtained are extremely variable. The dispersivities measured at different points along the length of an underground stream in the course of the same tracing experiment increase with distance (scale effect). If the fit of theoretical Sauty curves on the experimental curves works well for rising limbs, this is not always the case for falling limbs: a tailing effect or lag of the experimental curves compared to the theoretical ones is often observed. Micro-tracings have shown that the lag effect is linked more to the karst conduit geometry than to the types of flows (turbulent or laminar). Measurable tailing effect is induced by the presence of a single conduit enlargement (also called pool). Further, the experiments have shown that a succession of enlargements along the length of the underground stream causes a clear increase in the dispersivity and a "homogenisation" of the recovery curve which shows up by the apparent disappearance of the lag effect. These observations show clearly the influence of the heterogeneity of the karst conduit geometry on the breakthrough curves. This effect might be considered when one interprets the shape of the breakthrough curves especially for dispersivity estimation.

Structure et comportement hydraulique des aquifers karstiques, DSc. Thesis, faculte des Sciences de l'Universite de Neuchatel., 1998, Jeannin Py.
This thesis aims to provide a better knowledge of karst flow systems, from a functional point of view (behaviour with time), as well as from a structural one (behaviour in space). The first part of the thesis deals with the hydrodynamic behaviour of karst systems, and the second part with the geometry of karstic networks, which is a strong conditioning factor for the hydrodynamic behaviour. Many models have been developed in the past for describing the hydrodynamic behaviour of karst hydrogeological systems. They usually aim to provide a tool to extrapolate, in time and/or space, some characteristics of the flow fields, which can only be measured at a few points. Such models often provide a new understanding of the systems, beyond what can be observed directly in the field. Only special field measurements can verify such hypotheses based on numerical models. This is an significant part of this work. For this purpose, two experimental sites have been equipped and measured: Bure site or Milandrine, Ajoie, Switzerland, and Holloch site, Muotathal, Schwyz, Switzerland. These sites gave us this opportunity of simultaneously observe hydrodynamic parameters within the conduit network and, in drillholes, the "low permeability volumes" (LPV) surrounding the conduits. These observations clearly show the existence of a flow circulation across the low permeability volumes. This flow may represent about 50% of the infiltrated water in the Bure test-field. The epikarst appears to play an important role into the allotment of the infiltrated waters: Part of the infiltrated water is stored at the bottom of the epikarst and slowly flows through the low permeability volumes (LPV) contributing to base flow. When infiltration is significant enough the other part of the water exceeds the storage capacity and flows quickly into the conduit network (quick flow). For the phreatic zone, observations and models show that the following scheme is adequate to describe the flow behaviour: a network of high permeability conduits, of tow volume, leading to the spring, is surrounded by a large volume of low permeability fissured rock (LPV), which is hydraulically connected to the conduits. Due to the strong difference in hydraulic conductivity between conduits and LPV, hydraulic heads and their variations in time and space are strongly heterogeneous. This makes the use of piezometric maps in karst very questionable. Flow in LPV can be considered as similar to flow in fractured rocks (laminar flow within joints and joints intersections). At a catchment scale, they can be effectively considered as an equivalent porous media with a hydraulic conductivity of about 10-6 to 10-7 m/s. Flow in conduits is turbulent and loss of head has to be calculated with appropriate formulas, if wanting any quantitative results. Our observations permitted us to determine the turbulent hydraulic conductivity of some simple karst conduits (k',turbulent flow), which ranges from 0.2 to 11 m/s. Examples also show that the structure of the conduit network plays a significant role on the spatial distribution of hydraulic heads. Particularity hydraulic transmissivity of the aquifer varies with respect to hydrological conditions, because of the presence of overflow conduits located within the epiphreatic zone. This makes the relation between head and discharge not quadratic as would be expected from a (too) simple model (with only one single conduit). The model applied to the downstream part of Holloch is a good illustration of this phenomena. The flow velocity strongly varies along the length of karst conduits, as shown by tracer experiments. Also, changes in the conduit cross-section produce changes in the (tow velocity profile. Such heterogeneous flow-field plays a significant role in the shape of the breakthrough curves of tracer experiments. It is empirically demonstrated that conduit enlargements induce retardation of the breakthrough curve. If there are several enlargements one after the other, an increase of the apparent dispersivity will result, although no diffusion with the rock matrix or immobile water is present. This produces a scale effect (increase of the apparent dispersivity with observation scale). Such observations can easily be simulated by deterministic and/or black box models. The structure of karst conduit networks, especially within the phreatic zone, plays an important role not only on the spatial distribution of the hydraulic heads in the conduits themselves, but in the LPV as well. Study of the network geometry is therefore useful for assessing the shape of the flow systems. We further suggest that any hydrogeological study aiming to assess the major characteristics of a flow system should start with a preliminary estimation of the conduit network geometry. Theories and examples presented show that the geometry of karst conduits mainly depends on boundary conditions and the permeability field at the initial stage of the karst genesis. The most significant boundary conditions are: the geometry of the impervious boundaries, infiltration and exfiltration conditions (spring). The initial permeability field is mainly determined by discontinuities (fractures and bedding planes). Today's knowledge allows us to approximate the geometry of a karst network by studying these parameters (impervious boundaries, infiltration, exfiltration, discontinuity field). Analogs and recently developed numerical models help to qualitatively evaluate the sensitivity of the geometry to these parameters. Within the near future, new numerical tools will be developed and will help more closely to address this difficult problem. This development will only be possible if speleological networks can be sufficiently explored and used to calibrate models. Images provided by speleologists to date are and will for a long time be the only data which can adequately portray the conduit networks in karst systems. This is helpful to hydrogeologists. The reason that we present the example of the Lake Thun karst system is that it illustrates the geometry of such conduits networks. Unfortunately, these networks are three-dimensional and their visualisation on paper (2 dimensions) is very restrictive, when compared to more effective 3-D views we can create with computers. As an alternative to deterministic models of speleogenesis, fractal and/or random walk models could be employed.

Quantitative analysis of tracer breakthrough curves from tracing tests in karst aquifers, 1999, Field M. S.
Numerical analysis of tracer-breakthrough curves allow quick reliable estimates for many of the basic hydraulic and geometric parametersTracer-breakthrough curve analysis relies on the application of a continuous mass balance model for transport parameter estimationReadily obtained hydraulic parameters required for modeling include peak arrival time and peak velocity, longitudinal dispersion, and Peclet numberGeometric parameters include volume, cross-sectional area, and diameterSome boundary-layer effects can also be roughly estimated

Dispersion, retardation and scale effect in tracer breakthrough curves in karst conduits., 2001, Hauns M. , Jeannin P. Y. , Atteia O.

Dispersion, retardation and scale effect in tracer breakthrough curves in karst conduits, 2001, Hauns M. , Jeannin P. Y. , Atteia O. ,
Characteristics of tracer breakthrough curves in karst conduits are examined and compared to results generated using well known equations applied to porous media. The equations of the turbulent dispersion lead to a transport equation similar to the classical advection-dispersion equation for porous media with a slightly different meaning for the dispersion and advection terms. For investigations at the meter length scale, we used a three-dimensional (3-D) computational fluid dynamics (CFD) code to simulate tracer transport in several conduit geometries. The simulations show that turbulent dispersion can be considered as Fickian at a meter length scale of observation and that turbulent dispersivity depends linearly on the average flow velocity in the range of observed velocities. The simulations show that pools induce retardation (tailing of the breakthrough curve) due to flow reversal in eddies. Retardation has a complex relationship with the pool dimensions. Irregularity of the conduit cross-section along the investigated section clearly produces retardation. This is obvious at the meter length scale but may still be visible 10(3) m downstream from the injection point. A transfer function ('black box') approach is used for upscaling from a meter to a 10(3) m length scale. Before applying it to natural examples, the transfer function approach is tested by using the 3-D CFD code and appears to perform well. Several tests, based on numerical, laboratory and held experiments, of conduit segments which includes various dispersive features indicate that retardation tends to be transformed to symmetrical dispersion with distance. At large scale it appears that the dominant dispersion factor is the irregularity of the conduit geometry, which produces an increase in dispersivity with distance ('scale effect'), similar to that observed in porous media. In conclusion this suggests that retardation and high dispersion provide evidence of an irregular conduit, including either numerous dispersive features or large-scale ones (pools for example). Conversely no retardation and moderate dispersion (close to 0.012 m) must result from turbulent Row through a smooth conduit. (C) 2001 Elsevier Science B.V. All rights reserved

Microbiological decay of Naphthionate in water samples as a source of misinterpretation of tracer tests, 2001, Goldscheider N. , Hö, Tzl H. , Kottke K.

The UV fluorescent dye Naphthionate is often used for groundwater tracing due to its favourable properties. As it is invisible in the water, it was selected as a tracer for an experiment in the karstic catchment of the mineral springs of Stuttgart (Germany) where any risk of colouring had to be avoided. Irregular breakthrough curves indicated the decay of Naphthionate. It was possible to demonstrate that the decay does not occur in the aquifer but in the sampling bottles. Laboratory experiments proved that the decay is due to microbiological activity and favoured by room temperature while the light has no significant influence.


Efficient hydrologic tracer-test design for tracer-mass estimation and sample-collection frequency, 2. Experimental results, 2002, Field Ms,
Effective tracer-test design requires that the likely results be predicted in advance of test initiation to ensure tracer-test success. EHTD-predicted breakthrough curves (BTCs) for various hydrological conditions were compared with measured BTCs obtained from actual tracer tests. The hydrological conditions for the tracer tests ranged from flowing streams to porous-media systems. Tracer tests evaluated included flowing streams tracer tests conducted in small and large surface-water streams, a karst solution conduit, and a glacial-meltwater stream and porous-media systems conducted as natural-gradient, forced-gradient, injection-withdrawal, and recirculation tracer tests. Comparisons between the actual tracer tests and the predicted results showed that tracer breakthrough, hydraulic characteristics, and sample-collection frequency may be forecasted sufficiently well in most instances as to facilitate good tracer-test design. Comparisons were generally improved by including tracer decay and/or retardation in the simulations. Inclusion of tracer decay in the simulations also tended to require an increase in set average tracer concentration to facilitate matching peak concentrations in the measured BTCs, however. Both nonreactive tracer and reactive tracer predictions produced recommended sample-collection frequencies that would adequately define the actual BTCs, but estimated tracer-mass estimates were less precise

Forecasting Versus Predicting Solute Transport in Solution Conduits for Estimating Drinking-Water Risks, 2004, Field, Malcolm S.

Contaminant releases in karstic terranes can cause rapid and devastating affects on drinking-water supplies. Because future contaminant releases are likely it is necessary that local water managers develop release scenarios so as to be prepared prior to an actual contaminant release occurring. Release scenarios may be forecasted using appropriate historical data or they may be predicted using selected measured parameters. Forecasting contaminant releases to drinking-water supplies in karstic terranes is best accomplished by conducting numerous tracer tests from each potential source location to each exposure point so that acceptable solute-transport parameters for each solution conduit may be estimated from analyses of the breakthrough curves. Compositing the numerous breakthrough curves and fitting a quintic spline allows development of a single representative breakthrough curve that may then be used to forecast the effects of a release. Predicting contaminant releases is accomplished by combining basic measured field parameters for selected solution conduits in functional relationships for application in solute-transport models. The resulting breakthrough curve and solute-transport parameters can be used to predict the effects of a release. The forecasting and prediction methodologies were tested using a hypothetical release into a solution conduit developed in a karstic aquifer. Both methods were shown to produce reasonably acceptable results. The prediction methodology produced better time-of-travel results and better mass recovery and exposure concentration results than did the forecasting methodology.


Flow system dynamics and water storage of a fissured-porous karst aquifer characterized by artificial and environmental tracers, 2005, Einsiedl F,
Concentration breakthrough curves obtained from a tracer test and time series of environmental tracers were analyzed to characterize slow and preferential water flow in a karst aquifer of the Franconian Alb, Germany. Tritium (H-3) and chemical tracers (uranine, bromide, strontium) were measured during low flow conditions and a storm runoff event. The mean transit time of water along the conduits was determined using bromide. Environmental tracer data collected between 1969 and 2003 were modeled to estimate the mean transit time of H-3 in the fissured-porous karst system (diffuse flow). The modelling approach was also used to estimate the water volume of the karst system and the conduits. The results suggest that the total water volume in the fissured-porous karst aquifer is in the range of 57 X 10(6) m(3) and approximately 6% of the total water volume is stored in the soil zone and the epikarst. The water storage capacity of the conduits seems to be of minor importance. A mean transit time of bromide in the range of 14 h was calculated for the conduit flow. The fissures and the porous rock matrix have a calculated water saturated porosity of 5.5% and a mean transit time of approximately 62 years was calculated. Thus the porous rock matrix represents the major dilution and storage zone for pollutants in the karst system. (c) 2005 Elsevier B.V. All rights reserved

Long-term tracing in karstic aquifer reservoir for drinking water:, 2006, Rino Semeraro, Massimiliano Baldassi, Luciano Ballarin, Clarissa Brun, Luca D?amelio, Fulvio Forti
The chain of the Musi Mt (1,869.4 m) is one of the most important karst massifs of the Western Julian Fore-Alps (Italy). It corresponds to an east-west unicline dipping north. The structural northern slope, having glaciokarst morphologies, is conditioned by karst in calcareous rocks (Raethian-Liassic); the southern dolomitic slope (Dolomia Principale, Norian-Raethian), is less karstified and is characterized by trenches. On the northern slope, the Barmàn spring is located; on the southern slope the Voidizza Springs and the Torre Springs are located. The Torre Springs, fed by both the alluvial aquifer of the upper valley of the Torre Stream and by the carbonate aquifer of the Musi, supply the waterworks of western Friuli region managed by ?CAFC Consorzio Acquedotti Friuli Orientale?. Almost the whole feeding basin of the above-mentioned springs is placed in a protected area, managed by ?Ente Parco Naturale delle Prealpi Giulie?. Therefore, the zone is an important example of an area having high vulnerability due to karst and it is strategic for the water supply for an important part of Friuli. Formerly, two tracing tests were carried out injecting Uranine into the Pahor Abyss on the northern slope. From these tests it results that the waters of the karst area drain in the Uragano Cave and in the underlying Barman Spring. Only during heavy low water, when the underground watershed of the massif lowers, is it possible to observe traces of Uranine in the Torre Springs, since the most northern underground regions of the massif are drained. In order to understand better the underground water flow, a long-term tracing was carried out injecting Uranine in the the Pahor Abyss on 11th October 2005. The tracer test was supported by a chemical-physical study of the underground waters of the massif, in the period from 28th September 2005 to 13th January 2006. In this study flow measurements (Q), physical-chemical measurements on the field (TC, pH, E.C.20C), chemical analysis (Tot. hardness, TDS180, Alk. CaHCO3-, K+, Na+, Ca2+, Mg2+, Cl-, SO42-, NO3-, NH4+, B, SiO2, Li+, Rb+, Sr2+, Cd, Co, tot. Cr, Ni, Pb, Mn, Fe, Cu, As, Zn) and the analysis of the stable isotopes (δ18O, δD) were carried out. As for the tracing test two fluorometer probes were positioned: one at the Barmàn Spring, the other in the mixer between the 21 drainages and the capture well of the Torre Springs. Moreover, the Voidizza Springs were checked and regularly sampled. Uranine was found at the Barmàn Spring after 12.26 hours with a distance of about 1,500 m. It probably flowed in large karst conduits, at a theoretical speed of 120 m/h (3.3 cm/s). The breakthrough curves are very quick: Uranine wave extinguished in only three days, thus confirming that it is a high mountain system that reacts to impulses immediately. The E.C.20C of the Barmàn Spring is almost constantly lower than that of the Torre and Voidizza Springs, whereas the temperature of the Voidizza Springs is always the highest of all the waters measured. δ18O of the Barmàn Spring (between -9.0 ? and -9.1?) is always inferior to that of the springs placed on the southern slope (between -8.0? and -8.7 ?) and δD of the Barmàn Spring ranges between -55? and -63?. E.C.20C of the Barmàn Spring (between μS/cm 128.7 and μS/cm 188.0) is almost always inferior to the E.C.20C of the springs of the southern slope (between μS/cm 139.9 and μS/cm 228.0). Ca2+ and Mg2+ are absolutely predominant in all the waters, where the Ca2+ values of the Barman Spring (around 30 mg/L) and of the springs of the southern slope (between 30 mg/L and 31.8 mg/L) are similar, whereas at the Barman Spring Mg2+ is always lower (about 4.9 mg/L) than that of the springs of the southern slope (between 9.0 mg/L and 16.2 mg/L). This confirms that the southern springs are fed by a predominantly dolomitic aquifer (in particular the Voidizza Springs) compared with that of the northern slope. Among the minor elements it is possible to observe Cu and Fe at the Torre and Voidizza Springs, whereas here Sr is remarkable (between 13.9 μg/L and 18.3 μg/L) and diffused in the whole aquifer. SO42- and NO3- are low in all the waters.

Rapid karstic bypass flow in the unsaturated zone of the Yorkshire chalk aquifer and implications for contaminant transport, 2007, Allshorn Sjl, Bottrell Sh, West Lj, Odling Ne,
Tracer tests have been performed on the unsaturated zone of the East Yorkshire chalk aquifer, UK. Rapid tracer travel times through significant thicknesses of unsaturated chalk (15-38 m) indicate that bypass flow must occur through fractures. Transport processes in the unsaturated zone of the chalk aquifer thus have similarities to those in the vadose zone of more typically karstic limestone aquifers. Modelling of tracer breakthrough curves indicates that bypass flow is sufficiently rapid to significantly inhibit diffusional loss of tracer into the porous matrix of the chalk. The presence of rapid karstic bypass flow in the unsaturated zone of the chalk will limit the potential for attenuation of groundwater contaminants in this zone

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