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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. ...

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 roof drainage is precipitation runoff from roofs.?

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Your search for milandre test site (Keyword) returned 7 results for the whole karstbase:
Spatial variability of ground-water chemistry within a karst aquifer - the milandre test site, Swiss Jura., 2001, Perrin J. , Jeannin Py. , Zwahlen F.

Implications of the spatial variability of infiltration-water chemistry for the investigation of a karst aquifer: a field study at Milandre test site, Swiss Jura, 2003, Perrin J. , Jeannin P. Y. , Zwahlen F. ,

Epikarst storage in a karst aquifer: a conceptual model based on isotopic data, Milandre test site, Switzerland, 2003, Perrin K. , Jeannin P. Y. , Zwahlen F. ,
The Milandre test site is a karst aquifer characterized by diffuse infiltration, a well developed conduit network, and several tributaries feeding an underground river. Field data include discharge rate measurements, stable isotopes, weekly rainfall and spring-water isotope sampling, and detailed isotope sampling during three flood events. Flood sampling was carried out at several tributaries corresponding to conduit flow, vadose flow and seepage flow. Weekly sampling showed a strong buffering of the rainfall isotopic signal at the spring. This attenuation suggests an important mixing reservoir in the system. Flood events showed highly peaking hydraulic responses but buffered rain isotope responses. These results indicate that the soil and epikarst sub-systems have an important storage capacity. A conceptual model of flow and transport in the soil and epikarst zone is proposed: Soil plays an important role in mixing due to the presence of capillary water storage. Consequently dampened concentrations reach the epikarst despite a rapid hydraulic response. The epikarst acts as the storage element and distributes water as either a base flow component or a quick flow component. When recharge exceeds a given threshold, excess infiltrated water bypasses the soil and epikarst and reaches the saturated zone as fresh flow. Based on this model, the significance of phreatic storage is thought to be limited, at least in Milandre test site. Hence the saturated zone is seen mainly as a transmissive zone through its well developed conduit network. (C) 2003 Elsevier B.V. All rights reserved

A conceptual model of flow and transport in a karst aquifer based on spatial and temporal variations of natural tracers, 2003, Perrin, Jerome

Karst aquifers represent an important groundwater resource world-wide. They are highly vulnerable to contamination due to fast transport through the system and limited attenuation of contaminants. The two main hydrogeological approaches developed for studying flow and transport are: inference of the
system structure from karst spring hydrographs and chemographs; numerical modelling of flow and transport using a theoretical distribution of flow and transport field parameters. These two approaches lack of validation by detailed field measurements and observations. The main objective of this thesis is to “fill the gap” existing between field and model data. Observations of flow and transport parameters at several locations within the system were used to develop a conceptual model. This model was then compared to the existing models.
The main field test site is the Milandre karst aquifer, located in the Swiss tabular Jura. Natural tracers (major ions, oxygen-18, specific conductance) and discharge were measured on the underground river, its main tributaries, percolation waters, and the main spring. These data were collected on a long-term basis in order to assess the spatial variability of the parameters, and on a short time scale (i.e. flood events) in order to investigate the dynamic processes. Complementary sites (Brandt and Grand Bochat) were used for more observations at the base of the epikarst.
The proposed conceptual model considers four sub-systems: the soil zone, the epikarst, the unsaturated zone, and the phreatic zone. Each has its own specificity with respect to flow and transport. The soil zone controls the actual infiltration into the system. It contributes efficiently to groundwater storage. It mixes quickly stored water with fresh infiltrated water. Its thickness determines land-use: thick soils are generally cultivated whereas thin soils are under forested areas. The solutes concentration of soil waters depends on land-use for pollution-related parameters (nitrate, chloride, sulfate, potassium, sodium). Moreover the soil zone is the main source of CO2 which controls the limestone dissolution-related parameters. The epikarst zone contributes largely to groundwater storage. It distributes groundwater into vadose flow through conduits, and base flow through low permeability volumes (LPV) in the unsaturated zone. It is the sub-system where dissolution-related parameters are mostly acquired.
The unsaturated zone is seen as a transmissive zone connecting the epikarst to the horizontal conduit network of the phreatic zone. In case of flood events, some dissolution still occurs in this sub-system.
The phreatic zone is the partly flooded conduit network draining groundwater to the spring. It collects waters issued from the unsaturated zone, mixes the tributaries, and drain the water towards the discharge area. The role of phreatic storage appears to be limited for both hydraulics and transport.
Tributary mixing is a prominent process that shapes spring chemographs during flood events. In steady-state conditions, base flow is mainly sustained by the epikarst reservoir. Tracer concentrations are stable as the chemical equilibrium is already reached in the epikarst. Waters issued from the different tributaries mix in the conduit network, and the spring chemistry is the result of this mixing.
During flood events, transient flow induces non-linear mixing of the tributaries. The respective contributions of the tributaries change throughout the flood, and the spring chemographs vary accordingly. In case of important recharge, waters issued from other sources than the epikarst participate to the flood. First, soil water reaches the phreatic zone. Its characteristics are a dampened isotopic signal, and ionic concentrations differing from those of the epikarst. Second, fresh water directly issued from rainfall, may reach the phreatic zone. Its characteristics are a varying isotopic signal, and diluted ionic concentrations. The mixing components participating to the flood are controlled by the actual infiltration volume (or height). The limestone dissolution process is effective for the fresh and soil components of flow. However mixing processes play a more important role than dissolution for shaping the spring chemographs.
From a practical point of view, the project confirmed the prominent role of the soil zone and the epikarst on the solute transport in karst systems. This was already integrated in karst vulnerability mapping methods recently developed (EPIK, PI, VULK).

http://doc.rero.ch/record/2604/files/these_PerrinJ.pdf


Radon and CO2 as natural tracers to investigate the recharge dynamics of karst aquifers, 2011, Savoy Ludovic, Surbeck Heinz, Hunkeler Daniel

This study investigated the use of radon (222Rn), a radioactive isotope with a half-life of 3.8 days, and CO2 as natural tracers to evaluate the recharge dynamics of karst aquifer under varying hydrological conditions. Dissolved 222Rn and carbon dioxide (CO2) were measured continuously in an underground stream of the Milandre test site, Switzerland. Estimated soil water 222Rn activities were higher than baseflow 222Rn activities, indicating elevated 222Rn production in the soil zone compared to limestone, consistent with a 226Ra enrichment in the soil zone compared to limestone. During small flood events, 222Rn activities did not vary while an immediate increase of the CO2 concentration was observed. During medium and large flood events, an immediate CO2 increase and a delayed 222Rn activity increase to up to 4.9 Bq/L and 11 Bq/L, respectively occurred. The detection of elevated 222Rn activities during medium and large flood events indicate that soil water participates to the flood event. A soil origin of the 222Rn is consistent with its delayed increase compared to discharge reflecting the travel time of 222Rn from the soil to the saturated zone of the system via the epikarst. A three-component mixing model suggested that soil water may contribute 4–6% of the discharge during medium flood events and 25–43% during large flood events. For small flood events, the water must have resided at least 25 days below the soil zone to explain the background 222Rn activities, taking into account the half-life of 222Rn (3.8 days). In contrast to 222Rn, the CO2 increase occurred simultaneously with the discharge increase. This observation as well as the CO2 increase during small flood events, suggests that the elevated CO2 level is not due to the arrival of soil water as for 222Rn. A possible explanation for the CO2 trend is that baseflow water in the stream has lower CO2 levels due to gas loss compared to water stored in low permeability zones. During flood event, the stored water is more rapidly mobilised than during baseflow with less time for gas loss. The study demonstrates that 222Rn and CO2 provides value information on the dynamics of groundwater recharge of karst aquifer, which can be of high interest when evaluating the vulnerability of such systems to contamination.


Radon and CO2 as natural tracers to investigate the recharge dynamics of karst aquifers, 2011, Savoy Ludovic, Surbeck Heinz, Hunkeler Daniel

This study investigated the use of radon (222Rn), a radioactive isotope with a half-life of 3.8 days, and CO2 as natural tracers to evaluate the recharge dynamics of karst aquifer under varying hydrological conditions. Dissolved 222Rn and carbon dioxide (CO2) were measured continuously in an underground stream of the Milandre test site, Switzerland. Estimated soil water 222Rn activities were higher than baseflow 222Rn activities, indicating elevated 222Rn production in the soil zone compared to limestone, consistent with a 226Ra enrichment in the soil zone compared to limestone. During small flood events, 222Rn activities did not vary while an immediate increase of the CO2 concentration was observed. During medium and large flood events, an immediate CO2 increase and a delayed 222Rn activity increase to up to 4.9 Bq/L and 11 Bq/L, respectively occurred. The detection of elevated 222Rn activities during medium and large flood events indicate that soil water participates to the flood event. A soil origin of the 222Rn is consistent with its delayed increase compared to discharge reflecting the travel time of 222Rn from the soil to the saturated zone of the system via the epikarst. A three-component mixing model suggested that soil water may contribute 4–6% of the discharge during medium flood events and 25–43% during large flood events. For small flood events, the water must have resided at least 25 days below the soil zone to explain the background 222Rn activities, taking into account the half-life of 222Rn (3.8 days). In contrast to 222Rn, the CO2 increase occurred simultaneously with the discharge increase. This observation as well as the CO2 increase during small flood events, suggests that the elevated CO2 level is not due to the arrival of soil water as for 222Rn. A possible explanation for the CO2 trend is that baseflow water in the stream has lower CO2 levels due to gas loss compared to water stored in low permeability zones. During flood event, the stored water is more rapidly mobilised than during baseflow with less time for gas loss. The study demonstrates that 222Rn and CO2 provides value information on the dynamics of groundwater recharge of karst aquifer, which can be of high interest when evaluating the vulnerability of such systems to contamination.


Radon and CO2 as natural tracers to investigate the recharge dynamics of karst aquifers, 2011, Savoy Ludovic, Surbeck Heinz, Hunkeler Daniel

This study investigated the use of radon (222Rn), a radioactive isotope with a half-life of 3.8 days, and CO2 as natural tracers to evaluate the recharge dynamics of karst aquifer under varying hydrological conditions. Dissolved 222Rn and carbon dioxide (CO2) were measured continuously in an underground stream of the Milandre test site, Switzerland. Estimated soil water 222Rn activities were higher than baseflow 222Rn activities, indicating elevated 222Rn production in the soil zone compared to limestone, consistent with a 226Ra enrichment in the soil zone compared to limestone. During small flood events, 222Rn activities did not vary while an immediate increase of the CO2 concentration was observed. During medium and large flood events, an immediate CO2 increase and a delayed 222Rn activity increase to up to 4.9 Bq/L and 11 Bq/L, respectively occurred. The detection of elevated 222Rn activities during medium and large flood events indicate that soil water participates to the flood event. A soil origin of the 222Rn is consistent with its delayed increase compared to discharge reflecting the travel time of 222Rn from the soil to the saturated zone of the system via the epikarst. A three-component mixing model suggested that soil water may contribute 4–6% of the discharge during medium flood events and 25–43% during large flood events. For small flood events, the water must have resided at least 25 days below the soil zone to explain the background 222Rn activities, taking into account the half-life of 222Rn (3.8 days). In contrast to 222Rn, the CO2 increase occurred simultaneously with the discharge increase. This observation as well as the CO2 increase during small flood events, suggests that the elevated CO2 level is not due to the arrival of soil water as for 222Rn. A possible explanation for the CO2 trend is that baseflow water in the stream has lower CO2 levels due to gas loss compared to water stored in low permeability zones. During flood event, the stored water is more rapidly mobilised than during baseflow with less time for gas loss. The study demonstrates that 222Rn and CO2 provides value information on the dynamics of groundwater recharge of karst aquifer, which can be of high interest when evaluating the vulnerability of such systems to contamination.


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