International Journal of Geosciences, 2012, 3, 410-429 http://dx.doi.org/10.4236/ijg.2012.32046 Published Online May 2012 (http://www.SciRP.org/journal/ijg) Hydrogeochemical Variations of Groundwater of the Northern Jabal Hafit in Eastern Part of Abu Dhabi Emirate, United Arab Emirates (UAE) Ahmed Murad 1* , Faris Mahgoub 2 , Saber Hussein 1 1 Department of Geology, UAE University, Al-Ain, UAE 2 WJ Groundwater Ltd., Dubai/Jumierah Lakes Towers, Dubai, UAE Email: { * ahmed.murad, s_hussein}@uaeu.ac.ae, faris_mirghani@hotmail.com Received March 16, 2011; revised January 27, 2012; accepted March 2, 2012 ABSTRACT This study is aimed to assess and evaluate the suitability of groundwater of the area located to the south-east of Al-Ain area in the UAE using hydrogeochemcical approach. The chemical analyses of groundwater samples collected from the study area showed that the groundwater salinity is high which resulted from heavy groundwater pumping. High chloride concentrations in groundwater of Mubazarah and Neima might be attributed to the entrapped saline water within the limestone sequence of Jabal Hafit, or it can be the agricultural activities as it clear from the positive relationship be- tween Cl − and Br − . High sulphate concentrations in groundwater might be related to the presence of gypsum and anhy- drite within the limestone sequence of Jabal Hafit. The anionic and cationic compositions of groundwater indicate that the chloride and sodium ions are the dominant and presence of bicarbonate and sulphate may reflect the mixing of such water by the recent freshwater through the existing structural lineaments within the study area. The hydrochemical pa- rameters indicate a relative increase in the concentration of calcium, magnesium and sulphate ions and this could reflect the influence of carbonates and evaporite sediments. Keywords: United Arab Emirates; Salinity; Major Cations and Anions; Groundwater; Water Genesis 1. Introduction The study area is located within the vicinity of Al-Ain re- gion in which the climate is deficient in rainfall, with a mean annual rainfall of about 96.4 millimeters [1]. Al- Ain area is considered to be a better ephemeral surface water resource in the country due to the occurrence of flash floods. Ain Al-Faydah (Ain Bu Sukhanah) is the only spring with Al-Ain area, which is located about 15 Km south of Al-Ain and about 2 km west of Jabal Hafit. According to El-Shami [2], the spring produces from Miocene gypsum and clay layers through thin Quaternary loose sediments. The spring represents the discharge area of a deep water source which finds its way up through one of several thrust faults dissecting the area. The aquifer in the area is recharged by the infiltration of the precipitation in the interdune areas and gravel plains and also from Jabal Hafit. Another source of re- charge includes irrigation water, upward vertical re- charge from deeper rocks and infiltration of water lost from the leaky water transmission lines [3]. The domestic water requirements in the region were met from major aquifers. However, massive increases in domestic demands due to the annual population growth rate of up to 8% [4] has meant that groundwater re- sources have been placed under increasing stress, result- ing in declining water levels, and increasing groundwater salinity and a resultant decrease in total production. The widening gap between groundwater supply and domestic demand has been met from an expansionist po- licy of desalination using all types of production process under an ever increasing responsibility of the private sector. In 2003, the total domestic wellfield production in Abu Dhabi Emirate had reduced to only 26 Mm 3 /yr, meeting only 17% of the total domestic requirements in the Eastern Region. Since 1998, production from the do- mestic wellfields has decreased by over 60% [5]. The objective of this study is to analyze the ground- water chemistry of the aquifer systems within the study area in terms of the prevailing natural (climatic, geologi- cal and hydrgeological) and man-induced (mainly agri- cultural) conditions and to evaluate the suitability of groundwater for different purposes. 2. Geological and Hydrogeological Settings The study area is located South-Easterly from Al-Ain in * Corresponding author. Copyright © 2012 SciRes. IJG