During a rainfall water infiltration into an unsaturated soil, zones of saturation may be developed anywhere within the flow domain. Consequently, a natural question arises: under which conditions depending on the rate at which rain water is supplied, the initial moisture distribution in the soil, the presence of underground sources and the boundary permeability, the flow domain may be separate...

The unsaturated soil hydraulic properties, including soil water retention curve and hydraulic conductivity, are the crucial input parameters for simulating soil water and solute transport through the unsaturated zone at regional scales, and are expensive to measure. These properties are frequently predicted with pedotransfer functions (PTFs) using the routinely measured soil properties. 110 soi...

AK(y) [3] treat the equation of motion for moisture movement in an unsaturated soil to be effectively the same as Darcy’s Law. How credible is this perception? There are two ways to approach this question. One is to examine the way exThe integral in the denominator on the right-hand side of Eq. [3] represents the resistance to flow. In general, perimental data are mathematically interpreted, an...

To investigate processes that might affect chlorofluorocarbon (CFC) mixing ratios at the water table, a time series was obtained of unsaturated zone soil gas CFCs to depths of ca. 4 m at a site near New York City (NYC). Observed CFC 11, 12, and 113 mixing ratios were lower in winter than expected from either a local, high-resolution time series or remote atmospheric mixing ratios. A diffusion m...

0022-1694/$ see front matter 2012 Elsevier B.V. A http://dx.doi.org/10.1016/j.jhydrol.2012.09.048 ⇑ Corresponding author. Tel.: +86 2768775432; fax E-mail address: [email protected] (J. Yang). It is a long-lasting challenge in subsurface hydrologic modeling to develop numerically efficient algorithm for coupling unsaturated and saturated flow, especially in regional-scale modeling. In this stud...

This special issue of Soil Science celebrates the enormous accomplishments made during the past century or more in the field of soil science, including some of the key articles published in Soil Science during its 90 years of existence. In this article, we focus on the contributions in soil physics, exemplified by the articles of Willard Gardner (1919) and John Philip (1957c), both of which are...