Tillage practices can influence the pore size distribution (PSD) of soil, affecting soil physical and hydraulic properties as well processes that are essential for plant growth, hydrology, environmental studies modeling. A study was conducted to assess effect no-tillage (NT) conventional tillage (CT) on PSD derived from soil–water retention curves (SWRCs) using van Genuchten’s equation (vG) at ...

In this study, the aim was to compare experimental and empirical methods used for estimation soil water retention under different conditions. Soil samples were chosen represent examples of heavy, medium light structures. Water curves obtained in laboratory using standard method. The van Genuchten (1980) (vG), Brooks Corey (1964) (BC) empirically. Model parameters determined by artificial neural...

Data obtained from modified cone penetrometer experiments were used to estimate the hysteretic soil hydraulic properties with a parameter estimation technique which combined a numerical solution of the Richards equation with Marquardt-Levenberg optimization. The modified cone penetrometer was designed to inject water into a soil through a cylindrical screen, measure the infiltration rate with t...

Chemical factors and physical constraints lead to coupled effects during particle transport in unsaturated porous media. Studies on unsaturated transport as typical for soils are currently scarce. In unsaturated porous media, particle mobility is determined by the existence of an air-water interface in addition to a solid-water interface. To this end, we measured breakthrough curves and retenti...

hysteresis has been widely recognized in the soil water relationship. in this paper, a detailed review of hysteresis was performed in relation to its models. so far, different models have been suggested to describe hysteresis in the water retention curve (wrc) that could be categorized into two main groups: conceptual and empirical models. the models in the first group are based on the domain t...

Relatively small changes in the shape of the soil water retention curve near saturation can signi®cantly a€ect the results of numerical simulations of variably saturated ̄ow, including the performance of the numerical scheme itself in terms of stability and rate of convergence. In this paper, we use a modi®ed form of the van Genuchten±Mualem (VGM) soil hydraulic functions to account for a very ...

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Packed column and mathematical modeling studies were conducted to explore the influence of water saturation, pore-water ionic strength, and grain size on the transport of latex microspheres (1.1 microm) in porous media. Experiments were carried out under chemically unfavorable conditions for colloid attachment to both solid-water interfaces (SWI) and air-water interfaces (AWI) using negatively ...