Natural Groundwater Tracers for Hydrochemical Evolution Investigations

Natural groundwater tracers studies have been undertaken in Kuwait to determine the origin of recharge, relationship between different aquifers, movement and residence time of the groundwater, and the chemical evolution in the aquifers. The environmental isotope tracers used and analyzed were Carbon-14 with Carbon-13 and Tritium. However, the conservative tracer isotope of lighter elements in the groundwater such as Oxygen - 18 and Deuterium considered to determine the systematic changes in isotope ratios occur as groundwater undergoes a chemical processes. Other relevant field measured unstable parameters and chemical analysis were also made to support the concept of hydro chemical evolution in the aquifers. The groundwater are recharged by direct infiltration of rainfall and irrigation practices as an example in Wafra agricultural area. The different hydro geological regimes have characteristic isotopic composition which changes from depleted stable isotope composition in the Dammarn Limestone Aquifer to highly enriched values in the sandy aquifer of Kuwait Group aquifer. The origin of recharge of the different aquifers is discussed in the context of the regional hydrology.