ABSTRACT
The instantaneous profile method (also known as the internal drainage method) is used
primarily for direct (in situ) field measurement of the hydraulic conductivity (K ) versus matric head (c) relationship, K(c) [LT1], and=or the hydraulic conductivity versus volumetric water content (u) relationship, K(u) [LT1]. It is also occasionally used for in situ determination of u(c) desorption curves; and it may potentially be useful for in situ estimation of the capillarity relationships (Chapter 69), although this has not yet been attempted
(see Comment 7 in Section 83.4). An alternative field method for determining near-saturated
K(c) and capillarity relationships is given in Chapter 82. Laboratory methods for K(c) or K(u) determination are given in Chapter 80 and Chapter 81. Selected methods for estimating K(c), K(u), and u(c) from surrogate porous medium properties are given in Chapter 84. A discussion of the principles and parameters associated with the determination
of K(c), K(u), u(c), and the capillarity relationships appears in Chapter 69.
