Synergistic Increase In Evaporation by Soil Heterogeneity.

Evaporation of liquids from porous media can be significantly altered by the presence of heterogeneity in the media. Textural contrasts in soil can lead to synergistic enhancement in cumulative evaporation when the textural interface is vertical and intersects the evaporation front. This behavior, however, is not ubiquitous as not all texture combinations produce evaporation synergy. Evaporation of water from bi-textural assemblages of soil columns were investigated using the Hydrus 2D software for combinations of all 12 soil textures. To be presented is the proposed mechanism and the range of physical parameters that can lead to this very peculiar behavior of evaporation synergy, where the cumulative evaporation for a bi-textural assemblage is higher than it is for either texture by itself. Understanding this behavior can lead to improvements in our understanding of evaporative losses from soils, which are inherently heterogeneous, and also for improved design of construction materials where heterogeneity could be used as an advantage for drying of media and long term protection of structures.