Soil-Water Characteristic Curve Modeling at Low Water Content: Empirical and Semi-Empirical Approaches

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Résumé

In this paper, we evaluate the performance of the most widely used semi-empirical models (van Genuchten (1980), Fayer and Simmons (1995) and Fredlund and Xing (1994)) and, an empirical model, the Modified Kovacs (MK) model for the determination of soil-water characteristic curve at the low water contents of two horizons of a soil from Burkina Faso. Combining terms from capillary state and adsorbed state of soil water gives a physical basis for the Modified Kovacs model. Our study confirms that the use of semi-empirical models requires somewhat large dataset covering the entire range of water content while the empirical model MK requires only basic geotechnical properties of soil and a few experimental points to adjust the parameters m and ac of the model. It appears that the MK model, by its simplicity and lower cost for the acquisition of experimental data, is the most appropriate

Mots-clés

soil, water, arid, modelling, empirical