Groundwater aquifer parameters evaluation using artificial dye tracers

Due to the very limited availability of groundwater of suiTable quality in Kuwait, effective management of the groundwater in the country is very essential. For this, it is important to have the reliable hydrogeological characterization data of the Kuwait aquifers system. In the present study, we have used artificial dye tracers to characterize the groundwater aquifers. Multi-well, multi-tracer, forced gradient and natural gradient tracer tests were earned in different locations. Rhodhamine WT and Fluorescein dye tracers were used in the two main aquifers, upper Kuwait Group (KG) and lower Dammam Formation (DF). Fluorometer was used to measure the dye tracer concentrations. Tracer breakthrough curves analyzed using inverse modelling indicated that the groundwater flow in KG is matrix-dominated as opposed to the secondary porosity in DF, as indicated by high effective porosity (n_eff> 0.10) values. The upper KG aquifer indicated low dispersivity and moderate to high effective porosities and filtration velocity calculated is 0.0054 to 0.088 m/d. The tracer test results also indicated that aquifers are semi confined and interconnected; degree of confinement varied locally and are low. General groundwater flow direction is north east and are locally defined. The change in the flow system from the pre-development conditions was that a cone of depression had developed in DF, causing change in the inter-aquifer flow direction to downwards from KG into DF in Shegaya and Sulaibiya areas. DF flow direction was seen to be radially toward the wellfields, and DF pumping captured most of its pre-development discharge to the Arabian Gulf.