SALINE GROUNDWATER IN ISRAEL - ITS BEARING ON THE WATER CRISIS IN THECOUNTRY

One of the major causes for the deterioration of water quality bearing heavily on the water crisis in Israel is the ongoing contamination of its water resources by saline water bodies. The present paper reviews the geochemical processes forming saline water, lists and explains ce rtain chemical and isotopic parameters which enable understanding thes e processes and describes the saline groundwater bodies and various sa linization phenomena occurring in the country's various aquifers. Dete rioration of groundwater in Israel is caused by numerous natural proce sses such as encroachment of sea water, migration of connate, highly p ressurized brines penetrating into fresh groundwater, by subsurface di ssolution of soluble salts originating in surrounding country rocks an d by water-rock interaction. In addition to sea water, two saline wate r bodies were identified as the main factors causing salinization of f resh groundwater: (a) Ca-chloride brines encountered in the Jordan-Dea d Sea Rift Valley, in various parts of the Negev and of the Coastal Pl ain, and (b) Na-chloride saline water identified in the subsurface of the Negev and in the southern part of the Coastal Plain. Intensive exp loitation of groundwater in Israel has disturbed the natural equilibri um which prevailed between fresh and saline water. The newly establish ed groundwater flow regimes have facilitated the migration of saline w ater bodies, their participation in the active hydrological cycle and the progressive contamination of fresh groundwater. These processes wh ich were not anticipated by planners and water resources managers emph asize that large-scale groundwater exploitation was undertaken without giving sufficient consideration to the occurrence and subsurface migr ation of saline water and brines.