SFB 1313 Publication "Evaporation-Driven Density Instabilities in Saturated Porous Media"

New SFB 1313 publication (University of Stuttgart / TU Eindhoven / Utrecht University), published in the scientific journal Transport in Porous Media. The work has been developed within the SFB 1313 research projects A05,CX3, A02.

“Evaporation-Driven Density Instabilities in Saturated Porous Media”

Authors

• Carina Bringedal (University of Stuttgart, SFB 1313 research project A05)
• Theresa Schollenberger (University of Stuttgart, associated SFB 1313 research project CX3)
• G. J. M. Pieters (Utrecht University)
• C. J. van Duijn (TU Eindhoven)
• Rainer Helmig (University of Stuttgart, SFB 1313 spokesman, SFB 1313 research projects A02 and C02)

Abstract

Soil salinization is a major cause of soil degradation and hampers plant growth. For soils saturated with saline water, the evaporation of water induces accumulation of salt near the top of the soil. The remaining liquid gets an increasingly larger density due to the accumulation of salt, giving a gravitationally unstable situation, where instabilities in the form of fingers can form. These fingers can, hence, lead to a net downward transport of salt. We here investigate the appearance of these fingers through a linear stability analysis and through numerical simulations. The linear stability analysis gives criteria for onset of instabilities for a large range of parameters. Simulations using a set of parameters give information also about the development of the fingers after onset. With this knowledge, we can predict whether and when the instabilities occur, and their effect on the salt concentration development near the top boundary.