Effects of karst and geological structure on groundwater flow: the case of Yarqon-Taninim Aquifer, Israel

Dafny, Elad and Burg, Avi and Gvirtzman, Haim (2010) Effects of karst and geological structure on groundwater flow: the case of Yarqon-Taninim Aquifer, Israel. Journal of Hydrology, 389 (3/4). pp. 260-275. ISSN 0022-1694

Abstract

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.


Statistics for USQ ePrint 26274
Statistics for this ePrint Item
Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: © 2010 Elsevier B.V. Permanent restricted access to published version due to publisher copyright policy.
Faculty / Department / School: Historic - Faculty of Engineering and Surveying - Department of Agricultural, Civil and Environmental Engineering
Date Deposited: 29 Oct 2014 00:07
Last Modified: 31 Oct 2014 03:03
Uncontrolled Keywords: FEFLOW; Judea Group Aquifer; Karst; Messinian salinity crises; paleohydrology; Yarqon-Taninim
Fields of Research : 09 Engineering > 0907 Environmental Engineering > 090702 Environmental Engineering Modelling
04 Earth Sciences > 0406 Physical Geography and Environmental Geoscience > 040603 Hydrogeology
09 Engineering > 0905 Civil Engineering > 090509 Water Resources Engineering
Socio-Economic Objective: D Environment > 96 Environment > 9609 Land and Water Management > 960910 Sparseland, Permanent Grassland and Arid Zone Land and Water Management
Identification Number or DOI: 10.1016/j.jhydrol.2010.05.038
URI: http://eprints.usq.edu.au/id/eprint/26274

Actions (login required)

View Item Archive Repository Staff Only