Hydrology of the coastal sabkhas of Abu Dhabi, United Arab Emirates

Water fluxes were estimated and a water budget developed for the land surfa ce and a surficial 10-m-deep section of the coastal sabkhas that extend fro m the city of Abu Dhabi, United Arab Emirates, west to the border with Saud i Arabia. The fluxes were estimated on the basis of water levels and hydrau lic conductivities measured in wells and evaporation rates measured with a humidity chamber. In contrast with conceptual models proposed in earlier st udies, groundwater inflow is estimated to be small, whereas the largest com ponents of the water budget are recharge from rainfall and evaporation from the water table. Estimates within a rectilinear volume of sabkha, defined as 1 m wide by 10 km long by 10 m deep, indicate that about 1 m(3)/year of water enters and exits by lateral groundwater flow; 40-50 m(3)/year enters by upward leakage; and 640 m(3)/year enters by recharge from rainfall. Base d on the water and solute fluxes estimated for the upward leakage into the sabkha, 7-8 pore volumes of brine have entered the sabkha from below since the time the sabkha became saturated (7,000 years ago) as a result of the l ast global sea-level rise.