ABSTRACT
The well or borehole permeameter method (also known in the engineering literature as the
shallow well pump-in method) is used primarily for in situ or field measurement of fieldsaturated hydraulic conductivity, Kfs [LT
1], in unsaturated porous materials (e.g., soil, fill, etc.). It can also be used, however, for in situ estimation 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 number of PD pores per unit area, NP [L2] (Chapter 69). The most common form of this method uses wells on the order of 4-10 cm in diameter and 10-100 cm deep, although
greater well diameters and depths are possible. Both constant-head and falling-head
approaches are available (described in Section 76.2 and Section 76.3, respectively). Other
field methods for measuring Kfs include the ring infiltrometer (Chapter 77), the auger hole (Chapter 78), and the piezometer (Chapter 79) methods. Laboratory methods for measuring
saturated hydraulic conductivity, Ks, are described in Chapter 75; and selected methods for estimating Ks from surrogate porous medium properties are given in Chapter 84. A discussion of the principles and parameters associated with determination of Kfs and the capillarity parameters appears in Chapter 69.
