3D Modelling (geometry and connections) of carbonate massifs in structurally complex areas : An application to buried karst reservoirs of Languedoc (South France)
The US Geological Survey’s (USGS) Karst Interest Group (KIG) will hold its next conference on 28 April through 2 May 2014 in Carlsbad, New Mexico, at the headquarters of the National Cave and Karst Research Institute (NCKRI).
International Conference on Groundwater in Karst, with optional pre-and post-conference field trips, will be held in Birmingham, UK, between June 20-26, 2015.
A new electronic publication is available online from the Karst Waters Institute (Special Publication 18), consisting of selected papers and abstracts for the Hypogene Cave Morphologies symposium held February 2 - 7, 2014, on San Salvador Island, The Bahamas.
Registration for the 6th International Workshop on Ice Caves (IWIC-VI) is now open! The conference will be held in Idaho Falls, Idaho, USA, from 17-22 August 2014.
Did you know?
That aggressive water is 1. water having the ability to dissolve rocks. in the context of limestone and dolomite, this term refers especially to water containing dissolved carbon dioxide to form carbonic acid or, rarely, other acids. 2. quality of waters that attack metals and concrete chemically by dissolution .?
Checkout all 2699 terms in the KarstBase Glossary of Karst and Cave Terms
Featured article from geoscience journal
This study demonstrates the significant influences of the geological structure (especially folding and lithology) and the karst system on groundwater flow regime. Folds divert groundwater flow from the general hydraulic gradient; marly layers sustain several perched sub-aquifers above the regional aquifer; and karstification increases the hydraulic conductivity by several orders of magnitude. These phenomena are quantitatively demonstrated within the Yarqon-Taninim (YT) basin, Israel, which is a complex groundwater system, combining several (extremely) opposite characteristics: humid and arid recharge zones, phreatic and confined parts, shallow and deep sub-aquifers, stratified and relatively-homogeneous sub-basins, saline and fresh water bodies, as well as stagnant and fast-flowing groundwater regions.
We have introduced a 3D geological-based grid for the basin (for the first time). It was implemented into a numerical code (FEFLOW), which was used thereafter to analyze quantitatively the flow regime, the groundwater mass balance, and the aquifer hydraulic properties. We present up to date conceptual understanding and numerical modeling of the YT flow field, especially at its mountainous parts.
Based on the calibration procedure and the sensitivity analyses, we obtained the best-fitted hydraulic conductivity values for the aquifer mesh. The general phenomenon observed is that as groundwater flow quantity increases, the hydraulic conductivity also increases. We interpret this result by the karstification mechanism (including paleo-karst). Thus, where groundwater flow-lines converge and where groundwater discharge amount increases, the karstification process intensifies and permeability increases. Consequently, at the mountainous region, along the syncline axes, where groundwater flow-lines converge, higher conductivities are found.
Modeling results also exhibit that at the lowland confined area, the geological structure does not play a major role in directing groundwater flow. Rather, the flow field is controlled by the well-developed karst system and the relatively homogenous carbonate section. It is hypothesizes that the extensive karstification took place at the Messinian Salinity Crises, 5.5 Ma, during which groundwater heads as well as sea level were lowered by several 100 m.