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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 basin is 1. a general term used to define a ground-water flow system that has defined boundaries and may include permeable materials that are capable of storing or furnishing a significant water supply; the basin includes both the surface area and the permeable materials beneath it [22]. 2. the area throughout which ground water drains towards the same point; it can be larger than the accompanying surface water drainage basin if permeable layers extend outside of the topographic divide [16]. see also drainage basin.?

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Chemistry and Karst, White, William B.
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Your search for travel times (Keyword) returned 12 results for the whole karstbase:
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

FLOW PARAMETERS IN A SHALLOW CONDUIT-FLOW CARBONATE AQUIFER, INNER BLUEGRASS KARST REGION, KENTUCKY, USA, 1991, Thrailkill J. , Sullivan S. B. , Gouzie D. R. ,
In the carbonate aquifers which underlie most karst terrains, groundwater flow is through a dendritic system of solution conduits. In such aquifers, termed shallow conduit-flow aquifers. the methods used to mode) granular and fracture aquifers are not generally applicable. Investigations were conducted in the Inner Bluegrass Karst Region of central Kentucky with the objective of developing methods of modeling shallow conduit-flow aquifers as well as obtaining quantitative information on a specific portion of the aquifer to assist in its management for water supply purposes. In the Inner Bluegrass Karst Region, groundwater basins are developed. in each of which there is an integrated system of solution conduits which conducts recharge to a major spring. One of the largest of these groundwater basins feeds Royal Spring, which serves as the principal water supply for the town of Georgetown. The basin extends over 15 km to the southeast and most of its flow is furnished by underground diversions of Cane Run, a surface stream with headwaters near the center of the City of Lexington. The principal objectives of the field investigation were to determine discharges at the spring and travel times to the spring from discrete recharge points within the basin, termed swallets. The spring is ungaged. and an attempt was made to obtain a continuous discharge record by the dilution of dye introduced at a swallet. Comparison of the dye-dilution discharge record with stage discharges at the spring revealed substantial discrepancies which are believed to be caused by as much as five-sixths of the low-flow discharge from the upper portion of the basin bypassing the spring. The dye-dilution method, therefore, provided significant insights into the geometry of the conduit system of the groundwater basin although it proved unsatisfactory as a method of determining discharges at the spring. Analysis of the travel times and stage discharges provided information on the conduit geometry by modeling the flow as open-channel flow in a rectangular channel. Flow in the system is rapid, ranging from 140 to 590 m h-1. Although the flow rate increases with discharge, the relationship is not simple owing to substantial increases in conduit cross-sectional area at higher discharges. Flow is turbulent and subcritical under all conditions. The most surprising result was the very low depth of flow calculated; less than 17 cm at even the highest discharge. Although this must be considered an 'equivalent' depth, it is believed to indicate that active flow in shallow conduit-flow aquifers is generally in a thin zone just beneath the water table

Radiocarbon concentration and origin of thermal Karst waters in the region of the Bukk Mountains, northeastern Hungary, 1995, Hertelendi E. , Veres M. , Futo I. , Svingor E. , Miko L. , Lenart L. , Deak J. , Suveges M. ,
Karst springs are abundant in Hungary, and many are thermal (temperatures >30 degrees C). As thermal springs are a significant part of Hungary's water resources, it is important to quantify their travel times in the karst systems. Thus, we chose to measure T and delta(18)O in the water and delta(13)C and C-14 in dissolved inorganic carbon (DIC) in water from 50 thermal and nonthermal springs and wells in the Bukk Mountains, northeastern Hungary, Environmental isotope data confirm the karst waterflow pattern implied by earlier studies. We found the water in warm springs and boreholes to be mixtures of cold young and old thermal water. We also determined short mean-residence times for some large cold springs. The C-14 activities measured in these springs indicate that the recharge area of the karst aquifer is open to the atmosphere, and atmospheric CO2 contributes to the C-14 activity of these groundwaters. We observed good correlation between C-14 and H-3 activities and we determined negative correlations between C-14 concentration and delta(13)C values and temperature. From the delta(18)O values of the oldest thermal waters, we attribute their origin to precipitation during colder temperatures than at present

Hydrogeologic controls on the groundwater interactions with an acidic lake in karst terrain, Lake Barco, Florida, 1996, Lee T. M. ,
Transient groundwater interactions and lake stage were simulated for Lake Barco, an acidic seepage lake in the mantled karst of north central Florida. Karst subsidence features affected groundwater flow patterns in the basin and groundwater fluxes to and from the lake. Subsidence features peripheral to the lake intercepted potential groundwater inflow and increased leakage from the shallow perimeter of the lake bed. Simulated groundwater fluxes were checked against net groundwater flow derived from a detailed lake hydrologic budget with short-term lake evaporation computed by the energy budget method. Discrepancies between modeled and budget-derived net groundwater flows indicated that the model underestimated groundwater inflow, possibly contributed to by transient water table mounding near the lake. Recharge from rainfall reduced lake leakage by 10 to 15 times more than it increased groundwater inflow. As a result of the karst setting, the contributing groundwater basin to the lake was 2.4 ha for simulated average rainfall conditions, compared to the topographically derived drainage basin area of 81 ha. Short groundwater inflow path lines and rapid travel times limit the contribution of acid-neutralizing solutes from the basin, making Lake Barco susceptible to increased acidification by acid rain

Contribution of correlation and spectral analyses to the regional study of a large karst aquifer (Charente, France), 1998, Larocque M. , Mangin A. , Razack M. , Banton O. ,
The purpose of the study is to demonstrate that correlation and spectral analyses can contribute to the regional study of a large karst aquifer. An example is presented for the La Rochefoucauld karst aquifer (Charente, France). Different types of spatially distributed time series provide valuable spatio-temporal information for the karat aquifer. The available time series consist of the spring flow rates, the flow rates at different locations in sinking streams, the piezometric levels, the electrical conductivity and temperature of the water, the atmospheric pressure and the precipitation The analysis of the flow rates at the springs shows that the aquifer empties very slowly and has a large storage capacity. Hydrodynamic links were established between three of the four rivers flowing on the aquifer and the springs. The results also demonstrate the important spatial heterogeneity of the aquifer and indicate that the most rapid flow occurs in the northern part of the aquifer. Hourly piezometric and electrical conductivity time series indicate that the transmissivity of the aquifer varies when some conductive channels become desaturated during the low water period. The delays between the distributed recharge and the piezometric level, between the localized river input and the how rates at the springs and between the electrical conductivities in rivers and the main spring provide information on the travel times in the aquifer, The observation of earth tides and barometric effects indicate that this apparently unconfined aquifer has a confined behaviour. (C) 1998 Elsevier Science B.V. All rights reserved

Travel Times Along Selected Flow Paths of the Edwards Aquifer, Central Texas, 2001, Kuniansky E. L. , Fahlquist L. , Ardis A. F.

Flow path travel times in the structurally controlled, karstic Edwards aquifer were estimated using simulated ground-water levels obtained from a finite-element model. For this analysis, simulated monthly ground-water levels were averaged over an 11-year calibration period to minimize the transient effect of short-term recharge and discharge events. The 1978-89 calibration period was characterized by average to wetter-than-average climatic conditions; simulated water-level and spring-flow compared favorably with measured data. Flow paths for which travel times were estimated range from 1,250 to 10,000 feet wide and from about 8 to 180 miles long. Effective aquifer thickness and effective porosity can be highly variable and is poorly defined throughout most of the aquifer. Accordingly, travel-time estimates were computed within known or inferred thicknesses and porosities within known or inferred ranges of 350 to 850 feet and 15 to 35 percent, respectively. The minimum rock matrix porosity for each element was divided by 10 to estimate a minimum time of travel (a worst case time of travel). Travel times range from 14 to 160 years for a flow path from the Blanco River Basin to San Marcos Springs and from 350 to 4,300 years for a flow path from the West Nueces River Basin to Comal Springs. Travel times near the minimum of the ranges are similar in magnitude to those determined from tritium isotopes in spring water, thus supporting the hypothesis that effective porosity and effective thickness of the aquifer is less than the respective ranges. 


Runoff generation in karst catchments: multifractal analysis, 2004, Majone B. , Bellin A. , Borsato A. ,
Time series of hydrological and geochemical signals at two karst springs, located in the Dolomiti del Brenta region, near Trento, Italy, are used to infer how karst catchments work internally to generate runoff. The data analyzed include precipitation, spring flow and electric conductivity of the spring water. All the signals show the signature of multifractality but with different intermittency and non-stationarity. In particular, precipitation and spring flow are shown to have nearly the same degree of nonstationarity and intermittency, while electric conductivity, which mimics the travel time distribution of water in the karst system, is less intermittent and smoother than both spring flow and precipitations. We found that spring flow can be obtained from precipitation through fractional convolution with a power law transfer function. An important result of our study is that the probability distribution of travel times is inconsistent with the advection dispersion equation, while it supports the anomalous transport model. This result is in line with what was observed by Painter et al. [Geophys. Res. Lett. 29 (2002) 21.1] for transport in fractured rocks. (C) 2004 Elsevier B.V. All rights reserved

Ground-water residence times in unconfined carbonate aquifers, 2007, Worthington, Stephen R. H.
Tracers have been widely used in unconfined carbonate aquifers to measure groundwater velocities and travel times. Injected tracers have largely been used to measure travel times from sinking streams to springs. Environmental tracers have largely been used to estimate overall residence times in an aquifer, and give times that are typically one hundred times longer than estimates from injected tracers. Use of both environmental and injected tracers has enabled residence times and storage volumes to be calculated for both diffuse and conduit components in a number of aquifers. With the addition of permeability data it is possible to calculate storage and flow components for the matrix, fracture and channel components. Results show that the matrix of the rock provides almost all storage, but has very long residence times, especially in older carbonates. Channels provide little storage, account for most of the flow, and have very short residence times. Fractures play an intermediate role between the matrix and channels and have low storage and moderate residence times. These same contrasts are found in many different aquifers and are likely to be found in all unconfined carbonate aquifers. Thus these aquifers are marked not so much by ranging from conduit flow to diffuse flow types, but rather in having triple porosity with contrasting flow and storage properties in the matrix, fractures and channels. The combination of environmental and injected tracers provides a powerful tool for elucidating these contrasting properties.

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

Characterization of Spatial Heterogeneity in Groundwater Applications , 2009, Trinchero, Paolo

Heterogeneity is a salient feature of every natural geological formation. In the past decades a large body of literature has focused on the effects of heterogeneity on flow and transport problems. These works have substantially improved the understanding of flow and transport phenomena but still fail to characterize many of the important features of an aquifer. Among them, preferential flows and solute paths, connectivity between two points of an aquifer, and interpretation of hydraulic and tracer tests in heterogeneous media are crucial points that need to be properly assessed to obtain accurate model predictions. In this context, the aim of this thesis is twofold:

· to improve the understanding of the effects of heterogeneity on flow and transport phenomena
· to provide new tools for characterizing aquifer heterogeneity

First, we start by theoretically and numerically examine the relationship between two indicators of flow and transport connectivity. The flow connectivity indicator used here is based on the time elapsed for hydraulic response in a pumping test (e.g., the storage coefficient estimated by the Cooper-Jacob method, Sest). Regarding transport, we select the estimated porosity from the observed breakthrough curve (Φ est) in a forced-gradient tracer test. Our results allow explaining the poor correlation between these two indicators, already observed numerically by Knudby and Carrera (2005).

Second, a geostatistical framework has been developed to delineate connectivity patterns using a limited and sparse number of measurements. The methodology allows conditioning the results to three types of data measured over different scales, namely: (a) travel times of convergent tracer tests, ta, (b) estimates of the storage coefficient from pumping tests interpreted using the Cooper-a Jacob method, S est, and (c) measurements of transmissivity point values, T. The ability of the methodology to properly delineate capture zones is assessed through estimations (i.e. ordinary cokriging) and sequential gaussian simulations based on different sets of measurements.


Third, a novel methodology for the interpretation of pumping tests in leaky aquifer systems, referred to as the double inflection point (DIP) method, is presented. The real advantage of the DIP method comes when it is applied with all the existing methods independently to a test in a heterogeneous aquifer. In this case each method yields parameter values that are weighted differently, and thus each method provides different information about the heterogeneity distribution. In particular, the combination of the DIP method and Hantush method is shown to lead to the identification of contrasts between the local transmissivity in the vicinity of the well and the equivalent transmissivity of the perturbed aquifer volume.

Fourth, the meaning of the hydraulic parameters estimated from pumping test performed in leaky aquifers is assessed numerically within a Monte Carlo framework. A synthetic pumping test is interpreted using three existing methods. The resulting estimated parameters are shown to be space dependent and vary with the interpretation method, since each method gives different emphasis to different parts of the timedrawdown data. Finally, we show that by combining the parameter estimates obtained from the different analysis procedures, information about the heterogeneity of the leaky aquifer system may be inferred.
Fifth, an unsaturated highly heterogeneous waste rock pile is modeled using a simple linear transfer function (TF) model. The calibration of the parametric model provides information on the characteristic time of the flow through the matrix and on the fraction of the water that, within each section, is channeled through the macropores. An analysis of the influence of the scale on the results is also provided showing that at large scales the behavior of the system tends to that of an equivalent matrix reservoir masking the effects of preferential flow.


Effective porosity of a carbonate aquifer with bacterial contamination: Walkerton, Ontario, Canada, 2012, Worthington S. R. H. , Smart C. C. , Ruland W.

Preferential flow through solutionally enlarged fractures can be a significant influence on travel times and source area definition in carbonate aquifers. However, it has proven challenging to step beyond a conceptual model to implementing, parameterizing and testing an appropriate numerical model of preferential flow. Here both porous medium and preferential flow models are developed with respect to a deadly contamination of the municipal groundwater supply at Walkerton, Ontario, Canada. The preferential flow model is based on simple orthogonal fracture aperture and spacing. The models are parameterized from bore hole, gamma, flow and video logs resulting in a two order of magnitude lower effective porosity for the preferential flow model. The observed hydraulic conductivity and effective porosity are used to predict groundwater travel times using a porous medium model. These model predictions are compared to a number of independent estimates of effective porosity, including three forced gradient tracer tests. The results show that the effective porosity and hydraulic conductivity values closely match the preferential flow predictions for an equivalent fracture network of _10 m spacing of 1 mm fractures. Three tracer tests resulted in groundwater velocities of hundreds of meters per day, as predicted when an effective porosity of 0.05% was used in the groundwater model. These velocities are consistent with a compilation of 185 tracer test velocities from regional Paleozoic carbonate aquifers. The implication is that carbonate aquifers in southern Ontario are characterized by relatively low-volume dissolutionally enlarged fracture networks that dominate flow and transport. The porous matrix has large storage capacity, but contributes little to transport. Numerical models based on much higher porosities risk significantly underestimating capture zones in such aquifers. The hydraulic conductivity – effective porosity prediction framework provides a general analytical frame work for a preferential flow carbonate aquifer. Not only is the framework readily parameterized from borehole observations, but also it can be implemented in a conventional porous medium model, and critically tested using simple tracer tests.


Influence of conduit network geometry on solute transport in karst aquifers with a permeable matrix, 2013, Ronayne, M. J.

In karst aquifers with significant matrix permeability, water and solutes are exchanged between the conduits and carbonate matrix. Transport through the matrix increases thes pread of solutes and increases travel times. This study numerically evaluates advective solute transport in synthetic karst systems that contain 3D branching conduit networks. Particle tracking is performed to analyze the spatial and temporal transport history of solute that arrives at the conduit outlet. Three measures of transport connectivity are used to quantify the solute migration behavior: the skew ness of the particle arrival time distribution, the normalized fifth percentile of arrival times, and the fraction of the total travel time that occurs within conduits. All three of these metrics capture the influence of conduit network geometry on solute transport. A more tortuous network leads to enhanced conduit-matrix mixing, which reduces the transport connectivity and yields a broader distribution of solute arrival times. These results demonstrate that the conduit network geometry is an important control on solute transport in karst systems with a permeable matrix.


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