Karst and Cave RSS news feed Like us on Facebook! follow us on Twitter!
Community news

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. ...

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. ...

Speleology in Kazakhstan

Shakalov on 11 Jul, 2012
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 clusterite is see botryoid.?

Checkout all 2699 terms in the KarstBase Glossary of Karst and Cave Terms

What is Karstbase?

Search KARSTBASE:

keyword
author

Browse Speleogenesis Issues:

KarstBase a bibliography database in karst and cave science.

Featured articles from Cave & Karst Science Journals
Chemistry and Karst, White, William B.
Engineering challenges in Karst, Stevanović, Zoran; Milanović, Petar
See all featured articles
Featured articles from other Geoscience Journals
Geochemical and mineralogical fingerprints to distinguish the exploited ferruginous mineralisations of Grotta della Monaca (Calabria, Italy), Dimuccio, L.A.; Rodrigues, N.; Larocca, F.; Pratas, J.; Amado, A.M.; Batista de Carvalho, L.A.
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
See all featured articles from other geoscience journals

Search in KarstBase

Your search for conduit flow (Keyword) returned 72 results for the whole karstbase:
Showing 61 to 72 of 72
Relative importance of the saturated and the unsaturated zones in the hydrogeological functioning of karst aquifers: The case of Alta Cadena (Southern Spain), 2011, Mudarra M. , Andreo B.

From analysis of the hydrodynamic and hydrochemical responses of karst springs, it is possible to know the behaviour of the aquifers they drain. This manuscript aims to contribute to the characterization of infiltration process, and to determine the relative importance of the saturated zone and of the unsaturated zone in the hydrogeological functioning of carbonate aquifers, using natural hydrochemical tracers. Thus, chemical components together with temperature and electrical conductivity (both punctual and continuous records) have been monitored in three springs which drain Alta Cadena carbonate aquifer, Southern Spain. An evaluation of the percentage of the electrical conductivity frequency peaks determined for each of the three springs is linked to the chemical parameters that comprise the conductivity signal. One of these springs responds rapidly to precipitation (conduit flow system), due to the existence of a high degree of karstification in the unsaturated zone and in the saturated zone, both of which play a similar role in the functioning of the spring. Another spring responds to precipitation with small increases in water flow, somewhat lagged, because the aquifer has a low degree of karstification, even in the unsaturated zone, which seems to influence its functioning more strongly than does the saturated zone. The third spring drains a sector of the aquifer with a moderately developed degree of karstification, one that is intermediate between the other two, in which both the unsaturated zone and the saturated zone participate in the functioning of the spring, but with the latter zone having a stronger influence. These three springs show different hydrogeological functioning although they are in similar geological and climatic contexts, which show the heterogeneity of karst media and the importance of an adequate investigation for groundwater management and protection in karst areas.

Research highlights
- From analysis of the hydrodynamic and hydrochemical responses of karst springs. - Characterization of the relative importance of the saturated (SZ) and unsaturated (NSZ) zones - Villanueva del Rosario: NSZ and SZ play similar roles in the functioning of the system. ► Pita: NSZ seems to affect its functioning more than SZ. - Parroso: NSZ and SZ participate in the functioning of the system, but SZ is more active.


Wet season hydrochemistry of Bribin Cave in Gunung Sewu Karst, Indonesia, 2012, Tjahyo Nugroho Adji

This research was conducted on the Bribin River, the most important underground river in the Gunung Sewu Karst, Gunung Kidul, Java, Indonesia. The main purpose of this study was to define the wet-season hydrochemistry of this river. This research also focuses on identifying the relationship between hydrochemical parameters to provide better aquifer characterization.Water-level monitoring and discharge measurements were conducted over a 1-year period to define the discharge hydrograph. Furthermore, baseflow-separation analysis is conducted to determine the diffuse-flow percentage throughout the year. Water sampling for hydrogeochemical analysis is taken every month in the wet season and every 2 hours for two selected flood events. To describe the hydrogeochemical processes, a bivariate plot analysis of certain hydrochemical parameters is conducted. The results show that the diffuse-flow percentage significantly controls the river hydrochemistry. The domination of diffuse flow occurs during non-flooding and flood recession periods, which are typified by a high value of calcium and bicarbonate and low CO2 gas content in water. Conversely, the hydrochemistry of flood events is characterized by the domination of conduit flow and CO2 gas with low calcium and bicarbonate content. According to the wet-season hydrochemistry, it seems that the small- and medium-sized fractures in the Bribin aquifer still provide storage for the diffuse and fissure flows, although the conduit fracture is already developed.


Challenges and solutions in numeric modeling of regional karst aquifer systems, 2013, Kresic Neven, Mikszewski Alex

Challenges and solutions in numeric modeling of regional karst aquifer systems, 2013, Kresic Neven, Mikszewski Alex

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


CAVES AND KARST HYDROGEOLOGY OF JERUSALEM, ISRAEL, 2013, Frumkin Amos

 

The city of Jerusalem, Israel, is growing for ~4,000 years on karst terrain. Lacking closed depressions, surface topography seems fluvial, but karst is well demonstrated by speleology and subsurface hydrology. Several caves in the city were truncated by construction works, including an 800 m long river cave (longest limestone river cave in Israel), and a 200 × 140 × 90 m isolated chamber cave (largest chamber cave in Israel). Caves are being discovered at a growing rate, as construction works dig deeper into the subsurface in the crowded city. Some of them are eventually destroyed by the construction works; only presently accessible caves are discussed here. The hydrogeology and hydrochemistry of the Gihon, Jerusalem’s main karst spring, was studied in order to understand its behavior, as well as urbanization effects on karst groundwater resources. High-resolution monitoring of the spring discharge, temperature and electrical conductivity, as well as chemical and bacterial analysis demonstrate a rapid response of the spring to rainfall events and human impact. A complex karst system is inferred, including conduit flow, fissure flow and diffuse flow. Electrical conductivity is high compared to nearby springs located at the town margins, indicating considerable urban pollution in the Gihon area. The previously cited pulsating nature of the spring does not exist today. This phenomenon may have ceased due to additional water sources from urban leakage and irrigation feeding the spring. The urbanization of the recharge area thus affects the spring water dramatically, both chemically and hydrologically.


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.


Characterization and conceptualization of a relict karst aquifer (Bilecik, Turkey), 2013, Aydin H. , Ekmekci M. , Soylu M. E.

The carbonate rocks in Turkey have different hydrogeological properties as a result of controlling karstification factors, such as lithostratigraphy, source of energy gradient, tectonic activity, type of erosion base, fluctuation in sea level, and climate change in their extended areas. This study was undertaken for the characterization and conceptualization of the hydrogeological behavior of a unique example of the dissected relict karst aquifer, which is known as the Harmanköy-Beyyayla Karst System (HBKS) in Central Turkey. In order to obtain the conceptualization of the HBKS, properties of recharge, flow, storage, and discharge was analyzed. The contribution of allogenic-point recharge to the Beyyayla and Döşkaya aquifers occurs from the Beyyayla and Tozman sinkhole with approximately 85% of total recharge. The rest of the recharge takes place as autogenic-diffuse/point type from the limestone rock-mass. The recharge on the Nardın aquifer originates from direct precipitation onto the limestone area mainly as autogenic-diffuse and, to lesser extent, as autogenic-point. Groundwater flow occurs as conduit flow at the Beyyayla and Döşkaya aquifers and as dispersed flow at the Nardın aquifer. The evaluation of all parameters shows that the HBKS can be divided into three distinct sub-catchments, namely, the Beyyayla, Döşkaya, and Nardın, while it has two different hydrogeological system so Beyyayla and Döşkaya have similar characteristics.


DEEP TIME ORIGINS OF SINKHOLE COLLAPSE FAILURES IN SEWAGE LAGOONS IN SOUTHEAST MINNESOTA, 2013, Alexander Jr. E. C. , Runkel A. C. , Tipping R. G.

Three of the approximately twenty-three municipal wastewater treatment lagoons constructed in the 1970s and 1980s in southeastern Minnesota’s karst region have failed through sinkhole collapse. Those collapses occurred between 1974 and 1992. All three failures occurred at almost exactly the same stratigraphic position. That stratigraphic interval, just above the unconformable contact between the Shakopee and Oneota Formations of the Ordovician Prairie du Chien Group is now recognized as one of the most ubiquitous, regional-scale, karst hydraulic high-transmissivity zones in the Paleozoic hydrostratigraphy of southeastern Minnesota. These karst aquifers have been developing multi-porosity conduit flow systems since the initial deposition of the carbonates about 480 million years ago. The existence of syndepositional interstratal karst unconformities between the Oneota and Shakopee Formations and between the Shakopee and St. Peter Formations, were recognized in the 1800s. About 270 million years ago galena, sphalerite and iron sulfides were deposited in pre-existing solution enlarged joints, bedding planes and caves. The region has been above sea level since the Cretaceous and huge volumes of fresh water have flowed through these rocks. The regional flow systems have changed from east-to-west in the Cenozoic, to north-to-south in or before the Pleistocene. The incision of the Mississippi River and its tributaries has and is profoundly rearranging the ground water flow systems as it varies the regional base levels during glacial cycles. The Pleistocene glacial cycles have removed many of the surficial karst features and buried even more of them under glacial sediments. High erosion rates from row crop agriculture between the us1850s and 1930s filled many of the conduit systems with soil. Over eighty years of soil conservation efforts have significantly reduced the flux of mobilized soil into the conduits. Those conduits are currently flushing much of those stored soils out of their spring outlets. Finally, the increased frequency and intensity of major storm events is reactivating conduit segments that have been clogged and inactive for millions of years.The karst solution voids into which the lagoons collapsed have formed over 480 million years. The recognition and mapping of this major karst zone will allow much more accurate karst hazard maps to be constructed and used in sustainable resource management decisions.


Flow characterization in the Santee Cave system in the Chapel Branch Creek watershed, upper coastal plain of South Carolina, USA., 2013, Edwards A. E. , Amatya D. M. , Williams T. M. , Hitchcock D. R. , James A. L.

Karst watersheds possess both diffuse and conduit flow and varying degrees of connectivity between surface and groundwater over spatial scales that result in complex hydrology and contaminant transport processes. The flow regime and surface-groundwater connection must be properly identified and characterized to improve management in karst watersheds with impaired water bodies, such as the Chapel Branch Creek (CBC), South Carolina watershed, which has a long-term sampling station presently listed on an EPA 303(d) list for phosphorous, pH, and nitrogen. Water from the carbonate limestone aquifer of the Santee Cave system and spring seeps in the CBC watershed were monitored to characterize dominant flow type and surface-groundwater connection by measuring dissolved calcium and magnesium, total suspended solids, volatile suspended solids, alkalinity, pH, specific conductance, and stable isotopes (d18O, d2H). These measurements indicated that the conduit flow to Santee Cave spring was recharged predominantly from diffuse flow, with a slow response of surface water infiltration to the conduit. Qualitative dye traces and stage elevation at Santee Cave spring and the adjacent Lake Marion (equal to the elevation of the flooded portion of CBC) also indicated a relation between fluctuating base level of the CBC reservoir-like embayment and elevation of the Santee Limestone karst aquifer at the spring. Methods described herein to characterize the flow type and surface-groundwater connection in the Santee Cave system can be applied not only to watershed management in the Chapel Branch Creek watershed, but also to the greater region where this carbonate limestone aquifer exists. 


Deep conduit flow in karst aquifers revisited, 2014, Kaufmann Georg, Gabrovšek Franci, Romanov Douchko

Caves formed in soluble rocks such as limestone, anhydrite, or gypsum are efficient drainage paths for water moving through the aquifer from the surface of the host rock towards a resurgence. The formation of caves is controlled by the physical solution through dissociation of the host rock by water or by the chemical solution through reactions of the host rock with water enriched with carbon dioxide. Caves as large underground voids are simply the end member of secondary porosity and conductivity characterizing the aquifer.

Caves and their relation to a present or past base level are found both close to a past or present water table (water-table caves) and extending far below a past or present water table (bathy-phreatic caves). One explanation for this different speleogenetic evolution is the structural control: Fractures and bedding partings are preferentially enlarged around more prominent faults, thus the fracture density in the host rock controls the speleogenetic evolution. This widely accepted explanation [e.g. Ford and Ewers, 1978] can be extended by adding other controls, e.g. a hydraulic control: As temperature generally increases with depth, density and viscosity of water change, and particularly the reduction of viscosity due to the increase in temperature enhances flow. This hypothesis was proposed by Worthington [2001, 2004] as a major controlling factor for the evolution of deep-bathyphreatic caves.

We compare the efficiency of structural and hydraulic control on the evolution of a cave passage by numerical means, adding a third control, the chemical control to address the change in solubility of the circulating water with depth. Our results show that the increase in flow through deep bathy-phreatic passages due to the decrease in viscosity is by far outweighted by effects such as the decrease in fracture width with depth due to lithostatic stress and the decrease in solubility with depth. Hence, the existence of deep bathy-phreatic cave passages is more likely to be controlled by the structural effect of prominent faults.


Evaluating temporal changes in hydraulic conductivities near karst-terrain dams: Dokan Dam (Kurdistan-Iraq) , 2015, Dafny Elad, Tawfeeq Kochar Jamal, Ghabraie Kazem

Dam sites provide an outstanding opportunity to explore dynamic changes in the groundwater flow regime because of the high hydraulic gradient rapidly induced in their surroundings. This paper investigates the temporal changes of the hydraulic conductivities of the rocks and engineered structures via a thorough analysis of hydrological data collected at the Dokam Dam, Iraq, and a numerical model that simulates the Darcian component of the seepage. Analysis of the data indicates increased seepage with time and suggests that the hydraulic conductivity of the rocks increased as the conductivity of the grout curtain decreased. Conductivity changes on the order of 10−8 m/s, in a 20-yr period were quantified using the numerical analysis. It is postulated that the changes in hydraulic properties in the vicinity of Dokan Dam are due to suspension of fine materials, interbedded in small fissures in the rocks, and re-settlement of these materials along the curtain. Consequently, the importance of the grout curtain to minimize the downstream seepage, not only as a result of the conductivity contrast with the rocks, but also as a barrier to suspended clay sediments, is demonstrated. The numerical analysis also helped us to estimate the proportion of the disconnected karstic conduit flow to the overall flow.


Results 61 to 72 of 72
You probably didn't submit anything to search for