Soil physics is concerned with the fluxes of energy, fluids, and solutes in the three-phase soil system. Important applications include irrigation and drainage management, quantification and optimization of crop water use, soil erosion, organic matter management and carbon storage, soil compaction and its adverse effects on soil life and crop production, and greenhouse gas production and transport. Our primary research goal is to improve the understanding, measurement, and modeling of subsurface transport of water, energy, and solutes between the atmosphere and groundwater. This is accomplished by developing and combining state-of-the-art methods for measuring and numerically modeling flow and transport at laboratory and field scales.
Hydraulic properties of porous media
A particular focus of our research is the general methodological development of identification tools to determine effective transport processes for water in the unsaturated zone. To achieve this goal, we combine advanced measurement techniques with state-of-the-art inverse numerical modelling using flow and transport models. In this way, we obtain hydraulic properties in high resolution and quality and can test existing parameterisations and develop improved models.
Water resources and evaporation from soils
Soils play an important role in the evaporation dynamics of land surfaces. When water content is sufficiently high, atmospheric conditions control the amount of evaporation. When soils become dry, unsaturated hydraulic conductivity and vapour diffusion in the soil become limiting factors. Deciphering the complex interactions between topsoil and atmosphere helps to estimate the consequences of a changing climate on groundwater recharge in arid and semi-arid regions and the microclimate in future cities.
Soil physical measurement technology
In cooperation with a commercial manufacturer of soil physical measurement equipment, we develop automated systems for the determination of important soil hydraulic and soil physical properties. A current example is an innovative method for determining the particle size distribution of soils based on pressure measurements in a soil suspension. Particle size distribution is an important physical property of soils that controls many macroscopic physicochemical properties.
Reactive solute transport in unsaturated soils
To minimise pollution of groundwater resources, it is important to understand solute transport processes in soils. We improve our knowledge of these processes by combining measurements at different scales (from laboratory to field scale) and by applying and developing new modelling approaches.