Research Project AX3

An understanding of the flow and transport processes occurring at the interface and between porous medium and turbulent free-flow domains is necessary when evaluating fluxes across a soil-atmosphere interface. The flow dynamics close to the surface in each domain exhibit a strong coupling to each other, where the coupling often depends on characteristics of the interface. In order to evaluate these coupled processes, an understanding of the underlying flow concepts is imperative. Within this project, exchanges at the Soil-atmosphere interface are studied, and the effects of turbulence, interface roughness, non-isothermal, and compositional flow dynamics are all investigated. Coupled REV scale two domain models are used for a detailed investigation of interface dynamics, and reduced 1D models at a larger lysimeter/field scale are used in comparison. In addition to numerical investigations, experimental work at both a laboratory scale and a lysimeter/field scale are performed. Further extensions include the transport of Isotopes, Gases, and pesticides in the subsurface in order to address further closely related applications.

This has begun with an analysis of water isotopologue transport in the subsurface. Here, two model concepts at different scales, a large scale resistance function based model, and a detailed coupled two domain model have been used to compare the descritpion of evaporation and transport dynamics with detailed experimental data. Further, efforts are also being made to compensate for the data-poor issues at larger scales, where limited environmental monitoring is available at the area of interest, the near surface.