Hydrogeological Modeling of the Saline-Hot Springs at the Sea of Galilee, Israel
Haim Gvirtzman, Grant Garven and Gdaliahu Gvirtzman

ABSTRACT

Meteoric fresh groundwater from shallow aquifers and hot brines from deep aquifers mix while emerging from several springs along the western coast of the fresh-water lake, Sea of Galilee, located within the Dead Sea Rift Valley, Israel. After the rainy season, when elevations of the groundwater table rise in the regional aquifers and discharge rates of springs increase, solute concentrations decrease at Tabha springs, but surprisingly increase at Fulya springs, apparently suggesting two different salinization mechanisms. Two detailed geologic cross sections were constructed, one across the rift valley at Tabha and a second at Fulya, each about 6 km deep by 70 km long. The hydrodynamics in these cross-sections were analyzed using a two-dimensional finite element code that solves the coupled variable-density groundwater flow and heat transfer equations. Numerical simulations indicte that a topography-driven flow model explains both spring systems, and the opposite salinity behavior results from the different hydrogeological configurations of the two subsurface drainage basins. At Fulya, both aquifers, the shallow and the deeper ones, are partially phreatic, whereas at Tabha, the deeper aquifer is totally confined. The responses of springs to changes in elevation of groundwater table were simulated, reproducing field observations. This analysis has implications on the management scheme for the lake and its surrounding aquifers. de.