Prediction of soil water properties for hydrologic modeling

Water flow in soils can be characterized for many boundary and initial conditions by solving governing differential equations. Thus, a physically consistent means of quantifying water flow in soils in terms of the soil properties governing the movement of water and air exists. One reason why this state-of-the-art technology is not yet fully utilized is the difficulty of obtaining the required inputs which are the relationships between matric potential and hydraulic conductivity as a function of soil water content. Approximate water flow models based on physical principles or empirical results may simplify the computational requirements, however, inputs are still required. This paper presents procedures to (1) estimate input parameters for the Brooks-Corey, Campbell, and Van Genuchten soil water retention and hydraulic conductivity functions based on readily available soil properties, and (2) to estimate infiltration parameters.