Geoscience Reference
In-Depth Information
Fig. 10.2 Pattern of contaminant advance (water containing dye) in a partially saturated soil.
Note the high degree of spatial variability in the pattern, both laterally and with depth. Reprinted
from Ghodrati and Jury (
1992
). Copyright 1992 with permission of Elsevier
Figure
10.2
shows a typical pattern of contaminant migration through the upper
meter of a partially saturated soil.
To quantify such transport, the advection-dispersion equation, which requires a
narrow pore-size distribution, often is used in a modified framework. Van
Genuchten and Wierenga (
1976
) discuss a conceptualization of preferential solute
transport through ''mobile'' and ''immobile'' regions. In this framework, contami-
nants advance mostly through macropores containing mobile water and diffuse into
