Factors Influencing Infiltration, Flow, Instability and Movement of Toxics in Layered Field Soils

摘要

Application of solute transport theory based on homogeneous laboratory soil column experiments to field situations has been less than successful. Two mechanisms responsible for the discrepancy involve movement through macropores and flow instability or fingering. The latter is observed in soils where the top layer has a lower conductivity than the subsoil. The research presented in the report focuses on a description of unstable wetting fronts in the laboratory and for field soils. The results of the study have implications for monitoring systems and groundwater pollution prediction models applied to field soils where instability occurs.