DEFINITION OF GROUNDWATER-FLOW PATTERNS BY ENVIRONMENTAL TRACERS IN THE MULTIPLE AQUIFER SYSTEM OF SOUTHERN ARAVA VALLEY, ISRAEL

The present paper describes a model for identification and semi-quantitative evaluation of the different water bodies replenishing groundwater in the southern Arava Rift Valley. The potential sources of recharge into the alluvial aquifer of the valley were assessed by multivariable cluster analysis of environmental tracers such as dissolved ions and stable isotopes. This data was also used to determine the flow pattern to the valley and, within its alluvial aquifer, to the natural outlet of the Red Sea. Spatial variations in the chemical compositions of groundwater and of their isotopic ratios are explained as the result of differential rates of replenishment of various water bodies flowing to the Arava. The alluvial aquifer of the southern Arava Valley is recharged by the following water bodies: (1) lateral subsurface flow caused by infiltration of water from flash floods occurring in the neighbouring mountain massifs; (2) upward and lateral groundwater flow from sandstone and carbonate aquifers in the Negev and Edom mountains; and (3) leakage from deep-seated brine reservoirs. A complete groundwater flow pattern based upon hydrological, hydrochemical and isotopic data is presented in a compartmental configuration. © 1990.