Estimation of Soil Water Retention and Hydraulic Properties

Water flow in soils can be characterized, in principle, for many boundary and initial conditions by solving the proper governing differential equations. There are several reasons why this state-of-the-art technology is not yet fully utilized. One reason may be complexity and expense of computer based numerical solutions. However, a more important reason is the difficulty of obtaining the primary input which is the relationship between matrix 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, soil property inputs are still required.