Origin of water and solutes in inland and coastal sabkhas of eastern Saudi Arabia

Abstract

The applicability of ascending brine model which recently advanced to explain the origin of water and solutes in sabkhas based upon field measurement in Abu Dhabi coastal sabkha has been tested in this study. The model seems to be hydrologically balanced. In consistent to this model, the source of solutes in sabkhas of eastern Saudi Arabia is the upward leakage from the deep aquifers. However, the contribution of groundwater seeping through upward vertical flow from the underlying aquifers is 48%, local precipitation contributes 47% and lateral groundwater inflow supplies 5% of water into the study sabkha. This deviation in the source of water from the ascending brine model is largely due to inherent structural heterogeneity of the underlying aquifers geology. The structural heterogeneity includes fractures, sinkholes, karstification and salt halokinesis. The overall structural effects enable the system to maintain continuous water supply to sabkhas from the deep aquifers.