Anisotropy and depth-related heterogeneity of hydraulic conductivity in a bog peat. I: laboratory measurements

Anisotropy and heterogeneity of hydraulic conductivity (K) are suspected of greatly affecting rates and patterns of ground-water seepage in peats. A new laboratory method, termed here the modified cube method, was used to measure horizontal and vertical hydraulic conductivity (K(h) and K(v)) of 400 samples of bog peat. The new method avoids many of the problems associated with existing field and laboratory methods, and is shown to give relatively precise measurements of K. In the majority of samples tested, K(h) was much greater than K(v), indicating that the bog peat was strongly anisotropic. Log(10)K(h), log(10)K(v), and log(10) (K(h)/K(v)) were found to vary significantly with depth, although none of the relationships was simple. We comment on the scale dependency of our measurements. Copyright (C) 2002 John Wiley Sons, Ltd.