Isotopes and geochemical techniques in the study of managed aquifer recharge in the Middle East

Groundwater resources in many parts of the Middle East are under increased stress owing to increased demand for water from rapid population growth in recent decades. As large volumes of water are generated seasonally in arid areas during episodic storm events that drain into lowlands and are subsequently lost to evapotranspiration, there is potential to alleviate the stress on groundwater by implementing water harvesting techniques. Although simple in concept, successful and sustainable managed aquifer recharge (MAR) is dependent upon addressing numerous technical issues. Of these, characterizing local hydrogeological conditions and the resulting distribution of recharged water within the aquifer, the degree of mixing between recharge water and ambient groundwater, and residence times within the system are fundamental to the successful management of MAR schemes. The scope of isotope applications in MAR has not been thoroughly evaluated, with few studies of this kind in arid or semi-arid climates, and fewer (if any) within the Middle East. TC Project RAS/8/103 will assist the Member States involved to better manage aquifer recharge sceheme, through the use of isotopic techniques supported by conventional geochemical tracers