HR: 15:25h
AN: H13L-08    [Abstracts]
TI: Salinization Patterns in Sloping Aquifers - The Israeli Coastal Aquifer Case
AU: * Shavit, U
EM: aguri@technion.ac.il
AF: Technion, Department of Civil and Environmental Engineering, Haifa, 32000 Israel
AU: Solomon, S
EM: kirshiri@technion.ac.il
AF: Technion, Department of Civil and Environmental Engineering, Haifa, 32000 Israel
AB: The explanation of the salinization mechanisms of the Israeli Coastal Aquifer is under a severe dispute. Where some researchers claim that the salinity source lies under the bottom of the aquifer, others show that the salinity penetrates by seawater intrusion, through the Eocene formations along the eastern boundary of the aquifer, or due to infiltration through the vadose zone. The hypothesis of our research is that salinization patterns are highly related to the steep slope of the Saqiye group, which defines the aquifer bottom. We will show that the development of saline regions along the eastern boundaries can be explained by a simple solution of the flow and transport equations given that the slope of the aquifer bottom is steep enough and assuming that the saline water infiltrates through the vadose zone alone. By solving the one-dimensional and two-dimensional (vertical) flow and transport equations we have examined the influence of different parameters such as aquifer bottom slope, aquifer thickness, flux and concentration of the penetrating water through the vadose zone, flux and concentration of the penetrating water through the eastern boundary, hydrological parameters, and dynamic effects. We have found that non steady state solutions are needed to study the salinization phenomena. The initial increases in the salinity along the eastern boundary, as observed in the south part of the Israeli Coastal Aquifer, can be explained by salt penetration through the vadose zone alone. The implications of this conclusion are significant. Instead of addressing a salinization source that was thought to be located along the east boundary, the discussion should be focused on the interaction between the agricultural activities and the aquifer management strategies. It is reasonable to assume, however, that the salinity found in some regions along the aquifer is higher than the salinity of the vadose zone water. Therefore, the conclusion of the study is that a combination of vadose zone contribution and local brines penetration is the key to understanding the salinization process. The success of future solutions to the aquifer salinity problem will depend on the correct ratio between the contributions of these two sources.
DE: 1805 Computational hydrology
DE: 1829 Groundwater hydrology
DE: 1831 Groundwater quality
DE: 1832 Groundwater transport
DE: 1838 Infiltration
SC: Hydrology [H]
MN: Fall Meeting 2005