Experimental and numerical study of water and solute infiltration in layered porous media

• Published in: Journal of hydrology (Amsterdam) Vol. 84; no. 1; pp. 9 - 34
• Main Authors: Stauffer, Fritz, Dracos, Themistocles
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.04.1986; Elsevier Science
• Subjects: Earth sciences; Earth, ocean, space; Exact sciences and technology; Hydrology. Hydrogeology; Unconfined aquifers; Infiltration; Two dimensional model; Artificial recharge; Natural recharge; Two-dimensional models
• ISSN: 0022-1694; 1879-2707
• DOI: 10.1016/0022-1694(86)90042-9

In the present paper an experimental and numerical study of flow and transport processes occurring in natural and artificial recharge of phreatic aquifers is presented. The study is restricted to two-dimensional flow in a vertical plane and conservative tracers. The investigated porous medium consisted of a horizontally layered sand packing. Once the infiltration front reached the capillary fringe, the experiments showed a rapid change in the phreatic surface slope and thus a fast increase of the flow rate in the saturated domain. Outflow of the infiltrated solute was observed at much later times. It is shown that this fast response is due to capillary phenomena, i.e. to the hysteresis in the soil moisture characteristics and thus depends on the initial conditions in the capillary zone. It is also shown that the solute transport was dominated by advective transport mechanisms which are strongly influenced by the layering of the sand packing. The results are discussed with respect to their hydrological significance.