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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. ...

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That pathogenic bacteria is disease inducing bacteria [16].?

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Featured articles from Cave & Karst Science Journals
Chemistry and Karst, White, William B.
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Your search for pipe-flow (Keyword) returned 13 results for the whole karstbase:
Geophysical applications of heat and mass transfer in turbulent pipe flow, 1971, Wigley T. , Brown C. ,

HYDROLOGIC RESPONSE OF A KARST WATERSHED, 1994, Felton Gk,
A ground water catchment was instrumented as a karst hydrology and water quality laboratory to develop long-term flow and water quality data. This catchment located in Woodford and Jessamine Counties in the Inner Bluegrass, Central Kentucky encompasses approximately 1620 ha, 40 water wells, over 400 sinkholes, 2 karst windows, and 1 sinking stream. The land uses consist of approximately 59% beef pasture, horse farm, and golf course; 16% row crops; 6% orchard; 13%forest; and 6% residential. The instrumentation consisted of a recording rain gage, an H-flume, a water stage recorder, and an automated water sampler. Flow data for 312 days were analyzed, and a peak flow rate prediction equation, specific to this catchment, was developed Recession curves were analyzed and found to be of two distinct mathematical forms, log curves and exponential curves. Prediction equations were good for the log-type recession curve and fair for the exponential-type recession curve. For the exponential recessions, the peak flow rate was found to be bimodally distributed The recession events were classified as either high flow or low flow, with the point of separation at 113 L/s. It was hypothesized that the flow system was controlled by pipe flow above 113 L/s and by open channel flow below 113 L/s. Subsequent analysis resulted in adequate prediction for the low flow events. Explained variation associated with the high flow events was low and attributed to storage in the karst system that was not incorporated into the predictor equation

Determination of transmissivity from specific capacity tests in a karst aquifer, 1997, Mace R. E. ,
Specific capacity tests are useful for estimating transmissivity in aquifers that have few good-quality pump tests, In karst aquifers, this has been done by (1) correcting specific capacity for turbulent well loss and using analytical relationships between transmissivity and specific capacity, and (2) correcting specific capacity for well loss and deriving an empirical relationship between transmissivity and specific capacity. This study focuses on the uncertainties of estimating well loss and presents an empirical relationship between transmissivity and uncorrected specific capacity for a karst aquifer. Well loss is difficult to estimate without good-quality step-drawdown tests. Pipe-flow theory tends to underestimate well loss, and an empirical relationship between specific capacity and well-loss constant has a large prediction interval that leads to well loss exceeding measured drawdown, To overcome uncertainties of estimating web loss, transmissivity and uncorrected specific capacity were related for aquifer tests from the Edwards aquifer in Texas, The resulting best-fit line is T = 0.76(S-c)(1.08) for T and S-c in m(2) d(-1), with a coefficient of determination, R-2, Of 0.89 and a 95-percent prediction interval spanning approximately 1.4 log cycles, Though the prediction interval is large, approximate but useful estimates of transmissivity can be determined because the relationship extends over five orders of magnitude from 1 to 100,000 m(2) d(-1). The relationship is applicable in at least one other karst aquifer and therefore may be useful for others

A strategy for modeling ground water rebound in abandoned deep mine systems, 2001, Adams R, Younger Pl,
Discharges of polluted water from abandoned mines are a major cause of degradation of water resources worldwide, Pollution arises after abandoned workings flood up to surface level, by the process termed ground water rebound, As flow in large, open mine voids is often turbulent, standard techniques for modeling ground water flow (which assume laminar flow) are inappropriate for predicting ground water rebound. More physically realistic models are therefore desirable, yet these are often expensive to apply to all but the smallest of systems. An overall strategy for ground water rebound modeling is proposed, with models of decreasing complexity applied as the temporal and spatial scales of the systems under analysis increase. For relatively modest systems (area < 200 km(2)), a physically based modeling approach has been developed, in which 3-D pipe networks (representing major mine roadways, etc.) are routed through a variably saturated, 3-D porous medium (representing the country rock). For systems extending more than 100 to 3000 km(2), a semidistributed model (GRAM) has been developed, which conceptualizes extensively interconnected volumes of workings as ponds, which are connected to other ponds only at discrete overflow points, such as major inter-mine roadways, through which flow can be efficiently modeled using the Prandtl-Nikuradse pipe-flow formulation. At the very largest scales, simple water-balance calculations are Probably as useful as any other approach, and a variety of proprietary codes may be used for the purpose

Simulating time-varying cave flow and water levels using the Storm Water Management Model, 2002, Campbell Cw, Sullivan Sm,
The Storm Water Management Model (SWMM) is an Environmental Protection Agency code used to estimate runoff through storm water drainage systems that include channels, pipes, and manholes with storage. SWMM was applied to simulate flow and water level changes with time for a part of Stephens Gap Cave in Jackson County, Alabama. The goal of the simulation was to estimate losses from a surface stream to the cave. The cave has three entrances that can remove water from the surface stream. These entrances connect through several passages to an 8-m (27-ft) high waterfall in a dome room. After a storm, the walls of this dome room had leaves on the wall as high as 4.6 m (15 ft) above the floor. The model showed that the height of the leaves did not represent a water level that could have occurred following any recent storm.Campbell, Livingston and Garza in 1997 developed the CLG model to estimate losses from karst surface streams. This model treats losses as pipe flow from a reservoir and gives the loss flow rate as ~h0.5 where h is the depth of flow in the surface stream. Losses to Stephens Gap Cave calculated with SWMM varied as h1.8. This depth dependence is more characteristic of flow over a weir than of pipe flow.The SWMM-calculated losses to Stephens Gap Cave showed no hysteresis, that is, the rising and falling limbs of the stage-discharge plot followed the same curve. Loss curves with significant hysteresis are difficult to simulate with simple models such as CLG or a weir flow model. However, an SWMM model of a simple hypothetical cave demonstrated that storage in Stephens Gap Cave is far below that required to cause hysteresis. Losses from many karst surface streams can probably be adequately estimated with a calibrated weir flow model. The utility of SWMM for analyzing cave flows was established. SWMM produced stable solutions with very low continuity errors for this cave

Modeling of karst aquifer genesis: Influence of exchange flow, 2003, Bauer S, Liedl R, Sauter M,
[1] This paper presents a numerical model study simulating the early karstification of a single conduit embedded in a fissured system. A hybrid continuum-discrete pipe flow model (CAVE) is used for the modeling. The effects of coupling of the two flow systems on type and duration of early karstification are studied for different boundary conditions. Assuming fixed head boundaries at both ends of the conduit, coupling of the two flow systems via exchange flow between the conduit and the fissured system leads to an enhanced evolution of the conduit. This effect is valid over a wide range of initial conduit diameters, and karstification is accelerated by a factor of about 100 as compared to the case of no exchange flow. Parameter studies reveal the influence of the exchange coefficient and of the hydraulic conductivity of the fissured system on the development time for the conduit. In a second scenario the upstream fixed head boundary is switched to a fixed flow boundary at a specified flow rate during the evolution, limiting the amount of water draining toward the evolving conduit. Depending on the flow rate specified, conduit evolution may be slowed down or greatly impaired if exchange flow is considered

Simulation of the development of karst aquifers using a coupled continuum pipe flow model - art. no. 1057, 2003, Liedl R. , Sauter M. , Huckinghaus D. , Clemens T. , Teutsch G. ,
[1] This paper is intended to provide insight into the controlling mechanisms of karst genesis based on an advanced modeling approach covering the characteristic hydraulics in karst systems, the dissolution kinetics, and the associated temporal decrease in flow resistance. Karst water hydraulics is strongly governed by the interaction between a highly conductive low storage conduit network and a low-conductive high-storage rock matrix under variable boundary conditions. Only if this coupling of flow mechanisms is considered can an appropriate representation of other relevant processes be achieved, e.g., carbonate dissolution, transport of dissolved solids, and limited groundwater recharge. Here a parameter study performed with the numerical model Carbonate Aquifer Void Evolution (CAVE) is presented, which allows the simulation of the genesis of karst aquifers during geologic time periods. CAVE integrates several important features relevant for different scenarios of karst evolution: (1) the complex hydraulic interplay between flow in the karst conduits and in the small fissures of the rock matrix, (2) laminar as well as turbulent flow conditions, (3) time-dependent and nonuniform recharge to both flow systems, (4) the widening of the conduits accounting for appropriate physicochemical relationships governing calcite dissolution kinetics. This is achieved by predefining an initial network of karst conduits ('protoconduits'') which are allowed to grow according to the amount of aggressive water available due to hydraulic boundary conditions. The increase in conduit transmissivity is associated with an increase in conduit diameters while the conductivity of the fissured system is assumed to be constant in time. The importance of various parameters controlling karst genesis is demonstrated in a parameter study covering the recharge distribution, the upgradient boundary conditions for the conduit system, and the hydraulic coupling between the conduit network and the rock matrix. In particular, it is shown that conduit diameters increase in downgradient or upgradient direction depending on the spatial distribution (local versus uniform) of the recharge component which directly enters the conduit system

Conduit properties and karstification in the unconfined Floridan Aquifer, 2004, Screaton E. , Martin J. B. , Ginn B. , Smith L. ,
Exchange of water between conduits and matrix is an important control on regional chemical compositions, karstification, and quality of ground water resources in karst aquifers. A sinking stream (Santa Fe River Sink) and its resurgence (River Rise) in the unconfined portion of the Floridan Aquifer provide the opportunity to monitor conduit inflow and outflow. The use of temperature as a tracer allows determination of residence times and velocities through the conduit system. Based on temperature records from two high water events, flow is reasonably represented as pipe flow with a cross-sectional area of 380 m(2), although this model may be complicated by losses of water from the conduit system at higher discharge rates. Over the course of the study year, the River Rise discharged a total of 1.9 x 10(7) m(3) more water than entered the River Sink, reflecting net contribution of ground water from the matrix into the conduit system. However, as River Sink discharge rates peaked following three rainfall events during the study period, the conduit system lost water, presumably into the matrix. Surface water in high flow events is typically undersaturated with respect to calcite and thus may lead to dissolution, depending on its residence time in the matrix. A calculation of local denudation is larger than other regional estimates, perhaps reflecting return of water to conduits before calcite equilibrium is reached. The exchange of matrix and conduit water is an important variable in karst hydrology that should be considered in management of these water resources

EXAMINING A COUPLED CONTINUUM PIPE-FLOW MODEL FOR GROUNDWATER FLOW AND SOLUTE TRANSPORT IN A KARST AQUIFER, 2010, Hu B. X.
A coupled continuum pipe-flow (CCPF) model has been developed for groundwater flow and solute transport in a karst aquifer with conduits. Groundwater flow in conduits is simulated through a pipe flow model and flow in fissured matrix rock is described by Darcys law. Water mass exchange between the two domains is modeled by a firstorder exchange rate method. In this study, we investigate mathematical well-posedness (mathematical term, which means solution existence and uniqueness) of the CCPF model, develop a finite elementary method to numerically approximate the mathematical model and study the convergence of the numerical method. The study results prove the modeling approach is mathematically well posed and numerically converged. To study the accuracy of the CCPF model, a recently developed Stokes-Darcy (SD) model and CCPF model are compared with laboratory experimental results. It was found that the SD model simulations match well with experimental results, but the CCPF model overestimates the hydraulic head in the matrix, especially around the matrix and conduit interface. The model underestimates solute transport in the conduit and does not capture the plume distribution in the matrix. In comparison with the SD model, the CCPF model requires an additional parameter, the first-order mass exchange rate, and the parameter is normally obtained through inverse method curve fitting. The SD method may provide an approach to directly estimate the parameter value.

Calibrating the exchange coefficient in the modified coupled continuum pipe-flow model for flows in karst aquifers, 2011, Chen Nan, Gunzburger Max, Hu Bill, Wang Xiaoming, Woodruff Celestine

We investigate the validity of the popular coupled-continuum pipe-flow (CCPF) model for flow in a karst aquifer. The (Navier) Stokes-Darcy model is used as the “true model” for calibrating the exchange coefficient in the CCPF model by minimizing the relative differences between results from the two models or at least by having those differences being below a prescribed threshold value. We find that although the CCPF model is never in perfect agreement with the Stokes-Darcy model, there is an almost universal choice for a nearly optimal exchange coefficient such that the relative error is below one percent. Our numerics suggest that the nearly optimal choice of the exchange coefficient should be sufficiently large instead of being a small quantity that is proportional to the hydraulic conductivity, as suggested in existing literatures. We also show that this nearly optimal choice of exchange coefficient is robust under a wide range of model parameters. This result demonstrates that the CCPF model is a valid approximation for flows in karst aquifers as long as we set the fluid exchange coefficient sufficiently large and at least in the simple two-dimensional setting that we consider.


Comparison of a karst groundwater model with and without discrete conduit flow, 2013, Saller S. P. , Ronayne M. J. , Long A. J.

Karst aquifers exhibit a dual flow system characterized by interacting conduit and matrix domains. This study evaluated the coupled continuum pipe-flow framework for modeling karst groundwater flow in the Madison aquifer of western South Dakota (USA). Coupled conduit and matrix flow was simulated within a regional finite-difference model over a 10-year transient period. An existing equivalent porous medium (EPM) model was modified to include major conduit networks whose locations were constrained by dye-tracing data and environmental tracer analysis. Model calibration data included measured hydraulic heads at observation wells and estimates of discharge at four karst springs. Relative to the EPM model, the match to observation well hydraulic heads was substantially improved with the addition of conduits. The inclusion of conduit flow allowed for a simpler hydraulic conductivity distribution in the matrix continuum. Two of the high-conductivity zones in the EPM model, which were required to indirectly simulate the effects of conduits, were eliminated from the new model. This work demonstrates the utility of the coupled continuum pipe-flow method and illustrates how karst aquifer model parameterization is dependent on the physical processes that are simulated


Comparison of a karst groundwater model with and without discrete conduit flow, 2013, Saller S. P. , Ronayne M. J. , Long A. J.

Karst aquifers exhibit a dual flow system characterized by interacting conduit and matrix domains. This study evaluated the coupled continuum pipe-flow framework for modeling karst groundwater flow in the Madison aquifer of western South Dakota (USA). Coupled conduit and matrix flow was simulated within a regional finite-difference model over a 10-year transient period. An existing equivalent porous medium (EPM) model was modified to include major conduit networks whose locations were constrained by dye-tracing data and environmental tracer analysis. Model calibration data included measured hydraulic heads at observation wells and estimates of discharge at four karst springs. Relative to the EPM model, the match to observation well hydraulic heads was substantially improved with the addition of conduits. The inclusion of conduit flow allowed for a simpler hydraulic conductivity distribution in the matrix continuum. Two of the high-conductivity zones in the EPM model, which were required to indirectly simulate the effects of conduits, were eliminated from the new model. This work demonstrates the utility of the coupled continuum pipe-flow method and illustrates how karst aquifer model parameterization is dependent on the physical processes that are simulated.


Identification of the Exchange Coefficient from Indirect Data for a Coupled Continuum Pipe-Flow Model, 2014, Wu X. , Kugler Ph. , Lu Sh.

Calibration and identification of the exchange effect between the karst aquifers and the underlying conduit network are important issues in order to gain a better understanding of these hydraulic systems. Based on a coupled continuum pipe-flow (CCPF for short) model describing flows in karst aquifers, this paper is devoted to the identification of an exchange rate function, which models the hydraulic interaction between the fissured volume (matrix) and the conduit, from the Neumann boundary data, i.e., matrix/conduit seepage velocity. The authors formulate this parameter identification problem as a nonlinear operator equation and prove the compactness of the forward mapping. The stable approximate solution is obtained by two classic iterative regularization methods, namely, the Landweber iteration and Levenberg-Marquardt method. Numerical examples on noisefree and noisy data shed light on the appropriateness of the proposed approaches


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