Rapid field measurement of air entry value and hydraulic conductivity of soil as significant parameters in flow system analysis

Abstract

Field measurements of air entry value and hydraulic conductivity of soil are obtained with a covered cylinder infiltrometer equipped with standpipe and vacuum gage. Tests are normally completed in approximately 30 minutes. The resulting data are used to construct step functions relating hydraulic conductivity to (negative) soil water pressure for sorption and desorption. These functions may be used as simplified hydraulic conductivity characteristics to include negative‐pressure flow in the analysis of subsurface water movement. Several field and laboratory studies demonstrate the validity of the concepts and the technique.