Determining Soil Hydraulic Properties

Abstract

Hydraulic properties are required for modeling water and solute transport in unsaturated soils. The bottleneck for the successful application of numerical simulation models lays usually in their parameter estimation requirements. Methods to determine hydraulic properties can be classified into indirect and direct approaches. Indirect methods encompass the estimation of hydraulic properties by pedotransfer functions from more easily measured soil properties, and the prediction of the unsaturated hydraulic conductivity function from the water retention curve ( WRC ). In direct methods, observations of flow attributes from laboratory or field experiments are evaluated. This article reviews common methods to estimate the hydraulic conductivity function from the water retention characteristic and various direct measurement techniques in the laboratory and the field. We conclude with an outlook on contemporary developments in measurement techniques, stressing the key role of inverse modeling of experiments to derive optimum hydraulic properties and the importance of a future combination of noninvasive measurement techniques with inverse modeling by stochastic data fusion.

Application and recalibration of soil water retention pedotransfer functions in a tropical upstream catchment: case study in Bengawan Solo, Indonesia

“…Unfortunately, SWR information is not evenly available for every place on the earth (Hartemink, 2002;Minasny and Hartemink, 2011). The main reason is that laboratory and field measurements of SWR are labour intensive, time consuming and also require special equipment which leads to high costs (Durner and Lipsius, 2006). Therefore, information about SWR in many places remains unknown.…”

Inverse modelling of in situ soil water dynamics: investigating the effect of different prior distributions of the soil hydraulic parameters

“…A broad array of methods exists to determine these two constitutive relationships from laboratory or field experiments. An overview of these methods together with a discussion of their strengths and limitations can be found in Durner and Lipsius (2005), amongst others. With the ever increasing pace of computational power, availability of accurate and stable numerical solution schemes of the governing flow equations, and effective and efficient parameter optimization methods, the use of inverse modelling to determine soil hydraulic properties has become increasingly popular in the last few decades.…”

Simplified evaporation method for determining soil hydraulic properties

“…These soil hydraulic properties may be obtained by a variety of methods Durner and Lipsius, 2005). Most widely used are hydrostatic column experiments to derive hðhÞ (Dane and Hopmans, 2002) and the estimation of KðhÞ from hðhÞ by capillary bundle models like Mualem's integral (Mualem, 1976).…”

“…Most widely used are hydrostatic column experiments to derive hðhÞ (Dane and Hopmans, 2002) and the estimation of KðhÞ from hðhÞ by capillary bundle models like Mualem's integral (Mualem, 1976). Alternatively, transmission and capacity parameters can be determined simultaneously, e.g., by a series of steady-state experiments (Bouma et al, 1983;Dirksen, 1991;Durner and Lipsius, 2005), but the time demand for this method becomes prohibitively large for lower water contents. Most suitable is therefore the evaluation of transient flow experiments, such as multi-step inflow/outflow experiments (Durner et al, 1999) or evaporation experiments (Wind, 1968;Simunek et al, 1998a).…”