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Enviroscan Ukrainian Institute of Speleology and Karstology

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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 pan coefficient is coefficient to correlate a high rate of evaporation in a pan to an evaporation rate from larger water bodies [16].?

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Featured articles from Cave & Karst Science Journals
Chemistry and Karst, White, William B.
See all featured articles
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 dual-porosity (Keyword) returned 8 results for the whole karstbase:
Tracer tests and contaminant transport rates in dual-porosity formations with application to the WIPP., 1998, Ostensen Raymond W.

Controls on bacterial sulphate reduction in a dual porosity aquifer system: the Lincolnshire Limestone aquifer, England, 2000, Bottrell Sh, Moncaster Sj, Tellam Jh, Lloyd Jw, Fisher Qj, Newton Rj,
Chemical and sulphur isotopic analyses are presented of fissure-waters and pore-waters in the deep confined zone of a dual porosity carbonate aquifer. Some of the fissure-waters show good evidence for bacterial sulphate reduction, with low concentrations of sulphide present which is strongly to moderately depleted in 34S relative to sulphate. The sulphur geochemistry is best interpreted as mixing between: (i) a reduced water with sulphide ~60[per mille sign] depleted in 34S relative to sulphate; and (ii) a sulphate-rich water from up-dip in the aquifer. In addition, sulphide oxidation occurs where sufficiently oxidizing water is drawn in by abstractions. The large isotope fractionation factor associated with the sulphidic waters is probably the result of redox cycling of sulphur with little net reduction, rather than a true kinetic fractionation factor. By contrast, pore-waters in the 'sulphate reducing zone' show little or no evidence for the effects of sulphate reduction, despite the fact that the pore-waters represent a significant reservoir of sulphate for reduction. Some pore-waters have been modified recognizably by diffusional exchange with the fissure-waters, but the aquifer matrix has not been colonized by sulphate reducing bacteria, probably because porethroats in the limestone are too small for bacteria to pass. Physical exclusion of bacteria from the aquifer matrix and limited diffusional exchange are likely to exert fundamental controls on bacterial redox processes in dual porosity aquifer systems and other systems with low permeability due to small pore interconnections

Eogenetic karst from the perspective of an equivalent porous medium, 2002, Vacher H. L. , Mylroie J. E. ,
The porosity of young limestones experiencing meteoric diagenesis in the vicinity of their deposition (eogenetic karst) is mainly a double porosity consisting of touching-vug channels and preferred passageways lacing through a matrix of interparticle porosity. In contrast, the porosity of limestones experiencing subaerial erosion following burial diagenesis and uplift (telogenetic karst) is mainly a double porosity consisting of conduits within a network of fractures. The stark contrast between these two kinds of karst is illustrated by their position on a graph showing the hydraulic characteristics of an equivalent porous medium consisting of straight, cylindrical tubes (n-D space, where n is porosity, D is the diameter of the tubes, and log n is plotted against log D). Studies of the hydrology of small carbonate islands show that large-scale, horizontal hydraulic conductivity (K) increases by orders of magnitude during the evolution of eogenetic karst. Earlier petrologic studies have shown there is little if any change in the total porosity of the limestone during eogenetic diagenesis. The limestone of eogenetic karst, therefore, tracks horizontally in n-D space. In contrast, the path from initial sedimentary material to telogenetic karst comprises a descent on the graph with reduction of n during burial diagenesis, then a sideways shift with increasing D due to opening of fractures during uplift and exposure, and finally an increase in D and n during development of the conduits along the fractures. Eogenetic caves are mainly limited to boundaries between geologic units and hydrologic zones: stream caves at the contact between carbonates and underlying impermeable rocks (and collapse-origin caves derived therefrom); vertical caves along platform-margin fractures; epikarst; phreatic pockets (banana holes) along the water table; and flank margin caves that form as mixing chambers at the coastal freshwater-saltwater 'interface'. In contrast, the caverns of telogenetic karst are part of a system of interconnected conduits that drain an entire region. The eogenetic caves of small carbonate islands are, for the most part, not significantly involved in the drainage of the island

Analytical 1D dual-porosity equivalent solutions to 3D discrete single-continuum models. Application to karstic spring hydrograph modeling., 2002, Cornaton F. , Perrochet P.

Analytical 1D dual-porosity equivalent solutions to 3D discrete single-continuum models. Application to karstic spring hydrograph modelling, 2002, Cornaton F, Perrochet P,
One-dimensional analytical porosity-weighted solutions of the dual-porosity model are derived, providing insights on how to relate exchange and storage coefficients to the volumetric density of the high-permeability medium. It is shown that porosity-weighted storage and exchange coefficients are needed when handling highly heterogeneous systems-such as karstic aquifers-using equivalent dual-porosity models. The sensitivity of these coefficients is illustrated by means of numerical experiments with theoretical karst systems. The presented ID dual-porosity analytical model is used to reproduce the hydraulic responses of reference 3D karst aquifers, modelled by a discrete single-continuum approach. Under various stress conditions, simulation results show the relations between the dual-porosity model coefficients and the structural features of the discrete single-continuum model. The calibration of the equivalent 1D analytical dual-porosity model on reference hydraulic responses confirms the dependence of the exchange coefficient with the karstic network density. The use of the analytical model could also point out some fundamental structural properties of the karstic network that rule the shape of the hydraulic responses, such as density and connectivity. (C) 2002 Elsevier Science B.V. All rights reserved

Can we simulate regional groundwater flow in a karst system using equivalent porous media models? Case study, Barton Springs Edwards aquifer, USA, 2003, Scanlon B. R. , Mace R. E. , Barrett M. E. , Smith B. ,
Various approaches can be used to simulate groundwater flow in karst systems, including equivalent porous media distributed parameter, lumped parameter, and dual porosity approaches, as well as discrete fracture or conduit approaches. The purpose of this study was to evaluate two different equivalent porous media approaches: lumped and distributed parameter, for simulating regional groundwater flow in a karst aquifer and to evaluate the adequacy of these approaches. The models were applied to the Barton Springs Edwards aquifer, Texas. Unique aspects of this study include availability of detailed information on recharge from stream-loss studies and on synoptic water levels, long-term continuous water level monitoring in wells throughout the aquifer, and spring discharge data to compare with simulation results. The MODFLOW code was used for the distributed parameter model. Estimation of hydraulic conductivity distribution was optimized by using a combination of trial and error and automated inverse methods. The lumped parameter model consists of five cells representing each of the watersheds contributing recharge to the aquifer. Transient simulations were conducted using both distributed and lumped parameter models for a 10-yr period (1989-1998). Both distributed and lumped parameter models fairly accurately simulated the temporal variability in spring discharge; therefore, if the objective of the model is to simulate spring discharge, either distributed or lumped parameter approaches can be used. The distributed parameter model generally reproduced the potentiometric surface at different times. The impact of the amount of pumping on a regional scale on spring discharge can be evaluated using a lumped parameter model; however, more detailed evaluation of the effect of pumping on groundwater levels and spring discharge requires a distributed parameter modeling approach. Sensitivity analyses indicated that spring discharge was much more sensitive to variations in recharge than pumpage, indicating that aquifer management should consider enhanced recharge, in addition to conservation measures, to maintain spring flow. This study shows the ability of equivalent porous media models to simulate regional groundwater flow in a highly karstified aquifer, which is important for water resources and groundwater management. (C) 2003 Elsevier Science B.V. All rights reserved

Application of spectral analysis of daily water level and spring discharge hydrographs data for comparing physical characteristics of karstic aquifers, 2005, Rahnemaei M. , Zare M. , Nematollahi A. R. , Sedghi H. ,
Bivariate time series techniques (in spectral domain) of daily rainfall and water level of piezometers or discharge of springs in karstic aquifers are employed to evaluate the lag times (delay) of aquifers response to rainfall events. The evaluation results show that the physical characteristics of karstic aquifers can be compared with each other by using the outcomes of these analyses. With attention to dual porosity idea of karstic aquifers, two lag times (t(1), t(2)) can be computed, which, are related to flow of water through larger fractures (conduit flow) and matrix of the rock (diffuse flow), respectively. Results obtained from these functions, correspond to the findings of physical characteristics, compiled from field investigations. Comparable to dual porosity idea in regard to recharge through the larger fractures (in the first step) and finer porosity of the rock (in the second step), the idea of 'Dual Recharge' in karstic aquifers is presented. Application of these techniques is verified using daily rainfall and water level of Qara, Sabzpooshan and Kaftarak piezometers and daily discharge of Qasreqhomsheh karst spring in Maharlu basin in Iran (52 degrees 20 '-52 degrees 40 ' E and 29 degrees 20 '-29 degrees 40 ' N) having different degree of karstification in their surroundings. (c) 2005 Elsevier B.V. All rights reserved

Multiple technologies applied to characterization of the porosity and permeability of the Biscayne aquifer, Florida, 2011, Cunningham K. J. , Sukop M. C.

Research is needed to determine how seepage-control actions planned by the Comprehensive Everglades Restoration Plan (CERP) will affect recharge, groundwater flow, and discharge within the dual-porosity karstic Biscayne aquifer where it extends eastward from the Everglades to Biscayne Bay. A key issue is whether the plan can be accomplished without causing urban flooding in adjacent populated areas and diminishing coastal freshwater flow needed in the restoration of the ecologic systems. Predictive simulation of groundwater flow is a prudent approach to understanding hydrologic change and potential ecologic impacts. A fundamental problem to simulation of karst groundwater flow is how best to represent aquifer heterogeneity. Currently, U.S. Geological Survey (USGS) researchers and academic partners are applying multiple innovative technologies to characterize the spatial distribution of porosity and permeability within the Biscayne aquifer.


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