A physically based model of heterogeneous hillslopes: 2. Effective hydraulic conductivities

Abstract

Using the results of a fully three‐dimensional model of variably saturated flow on a heterogeneous hillslope, the concept of equivalent homogeneous hillslopes is explored. By considering single realizations of random patterns of saturated hydraulic conductivity, attempts are made to determine single effective hydraulic conductivity values capable of reproducing both subsurface and surface flow hydrographs. For the case of high‐permeability soils, effective parameters were found to reasonably reproduce the hillslope hydrograph, although there was no consistent relationship between the effective values and the moments of the spatial distributions. For the case of low‐permeability soils, characterized by surface flow domination of the runoff hydrograph, single effective parameters were not found to be capable of reproducing both subsurface and surface flow responses. Furthermore, the event dependency of effective conductivity values under such conditions was demonstrated.

A modeling study of heterogeneity and surface water-groundwater interactions in the Thomas Brook catchment, Annapolis Valley (Nova Scotia, Canada)

“…averaging schemes) are appropriate for establishing an effective parameter value (e.g. Philip, 1980;Binley et al, 1989;Bachu and Cuthiell, 1990;Kim and Stricker, 1996). The latter approach relies on having sufficient data to characterize the heterogeneity.…”

Measurement Techniques for Wastewater Filtration Systems

“…A common practice in hydrology is to use the geometrical mean of the dataset as a more representative improvement on either the arithmetic or harmonic means (Binley et al, 1989). Representative homogeneous values for hydraulic conductivity are however generally misleading, as in actuality hydraulic conductivity spans several orders of magnitude.…”

Concept Formation in Scientific Knowledge Discovery from a Constructivist View

“…The unsaturated version of Darcy's law is Richards' equation [50]. Representative models obtained from the laboratory environment (like Equations 1-2) are of limited usefulness for real heterogeneous slopes [51]. The applicability of a lab-induced model to real-time situations depends on how well one can address uncertainties in initial condition, time-varying inputs and time-invariant parameters.…”