Transient Effect of Battery of Injection Wells on Seawater Intrusion

Abstract

The transient effect of battery of injection wells on seawater intrusion into coastal confined aquifers is analyzed using a quasi-three-dimensional areal finite-element model derived based on the sharp interface approach. Linear triangular elements are used to discretize the domain. The validity of the model is tested using the theoretical solutions and experimental results. The model is then used to carry out detailed parametric studies on the efficacy of battery of injection wells in controlling seawater intrusion. Hypothetical cases over a wide practical range are considered for this purpose. In the study, the motion of the interface is tracked for different combinations of the well spacing, injection rate, and the duration. Relationships are established between the key parameters in nondimensional forms, which have wider practical application. The injection wells are found to be effective in controlling the intrusion over a longer period of operation, running into several years. Reduction of intrusion up to 60–90% is achievable under favorable conditions. A specific example is solved to illustrate the usefulness of the results.