Author(s): N. E. Kotsovinos; D. Andreakou; P. B. Angelidis
Keywords: Porous media; Artificial recharge; Density stratified aquiferintrusion; Gravity current
Abstract: This paper presents the results of laboratory experiments conducted to study the two dimensional intrusive gravity currents produced by a constant inflow into a density stratified aquifer. A semi-empirical solution is offered for the flow produced in density stratified aquifer due to the artificial recharge by a two dimensional source of constant strength (line source), embedded in the porous medium of uniform porosity. The artificial groundwater recharge scheme examined in this study, is accomplished by injection from a perforated pipe in a linearly density stratified porous medium of uniform porosity. The density of the recharging water is assumed equal to the density of the stratified ambient fluid at the level of the recharging pipe source. It is observed that the intrusion forms a thin layer at the elevation of the source. Balances of the forces that drive and retard the flow indicate that the intrusion is characterized only by one spreading regime: the pressure (buoyancy) force balanced by the viscous Stokes forces on the numerous grains. It is found theoretically that the length of the intrusion L (t) increases with time according to the relation L (t) ～ t`m, where m=2/3. The experimental results seem to confirm the derived spreading relation.