ESTIMATION OF GARDNER-RUSSO MODEL PARAMETERS FOR SOIL WATER RETENTION CURVES USING HORIZONTAL INFILTRATION DATA

摘要

The accuracy of water flow and solute transport predictions depends on the reliability and accuracy of soil hydraulic properties. The main soil hydraulic properties are soil water retention curve and soil hydraulic conductivity function. Since direct methods for measurement of soil hydraulic properties are time-consuming and expensive, it is important to develop analytical methods. In this paper, the parameters of Gardner-Russo model for soil retention curves were obtained based on the rules of onedimensional soil water infiltration. The relationship between infiltration time and cumulative infiltration,infiltration rate and wetting front were deduced, and fitted to the numerical infiltration results with coefficients of determination from 0. 9969 -0. 9997. With measured saturated soil water content,residual soil water content, initial soil water content and saturated soil hydraulic conductivity, a simple method to estimate the parameters of Gardner-Russo model was developed based on the relationships. Experimental data and numerical simulations of water flow were used to evaluate the analytical method. The analytical method provides a simple and quick transient water flow approach to estimate soil hydraulic properties.