ABSTRACT
The ring infiltrometer methods are used primarily for in situ or field measurement of fieldsaturated hydraulic conductivity, Kfs [LT
1], in unsaturated porous materials (e.g., soil). They can also be used, however, for in situ determination of the capillarity parameters: matric flux potential, fm [L
2T1], sorptive number, a* [L1], the effective Green-Ampt wetting front pressure head, cf [L], sorptivity, S [LT
1=2], flow-weighted mean pore diameter, PD [L], and the number of PD pores per unit area, NP [L2]. A discussion of the principles associated with determination of Kfs and the capillarity parameters appears in Chapter 69.
