Soil-water interactions in shrink-swell clays: measurements and models across scales

Ryan D. Stewart, Virginia Polytechnic Institute and State University, Crop and Soil Environmental Sciences, Blacksburg, United States, David Earl Rupp, Oregon State University, Oregon Climate Change Research Institute, Corvallis, United States, Majdi R Abou Najm, American University of Beirut, Beirut, 1107, Lebanon and John Steven Selker, Oregon State University, Corvallis, OR, United States
Abstract:
Shrink-swell clay soils, which are characterized by crack networks that form as the soil dries, are found all over the globe, with up to 350 million hectares being classified as either Vertisols or verticintergrades. When open, soil cracks can exert substantial influence on hydrological processes; however, up until now our ability to quantify and predict soil cracking behavior in real soils has been limited due to insufficient measurements and models.

Using measurements taken at multiple scales in the laboratory and in the field, as part of a long-term study, we have developed a new, parsimonious model that integrates the behavior of individual soil clods with plot- and catchment-scale processes such as infiltration and overland flow. Even though the model was developed for vertic soils, it potentially can be applied to other clayey soils in order to better describe common processes such as infiltration, preferential flow, and nutrient transport.

Back to: Multiscale Preferential Flow from Soils to Fissured/Karst Systems: Hydrologic, Geochemical, and Biological Implications I