subsurface drainage systems are used to control the depth of the water table and to reduce or prevent soil salinity. water flow in these systems is described by the boussinesq equation, and the advection-dispersion equation coupled with the boussinesq equation is used to study the solute transport. the objective of this study was to propose a finite difference solution of the advection-dispersi...

A numerical model that includes the effects of mass transfer between mobile and immobile liquid phases, advection, hydrodynamic dispersion, and melt-freeze episodes was developed to simulate ionic solute transport in melting snow. Model calibration using a tracer-infused laboratory snowpack experiment yielded a dispersivity of 0.05 cm and a mobile-immobile phase mass-transfer coefficient of 4 3...

Dispersive soils which occur in many parts of the world are easily erodible and segregate in water pose serious problems of stability of earth and earth retaining structures. The mechanism of dispersivity of soils is reasonably well understood. However there is simple method to identify the dispersivity of the soils and even more difficult to quantify the dispersivity. Visual classification, At...

[1] Traditionally, analytical solutions for heat transport in soils have been used in combination with heat pulse probe (HPP) measurements to estimate soil thermal properties. Although the analytical method has resulted in accurate estimation of soil thermal properties, we suggest that parameter estimation using inverse modeling (IM) provides new and unique opportunities for soil thermal charac...

[1] This study proposed a new mobile‐immobile model (MIM) to describe reactive solute transport with scale‐dependent dispersion in heterogeneous porous media. The model was derived from the conventional MIM but assumed the dispersivity to be a linear or exponential function of travel distance. The linear adsorption and the first‐order degradation of solute were also considered in the model. The...

Abstract Dispersivity is a measurable parameter in soil porous media that used for studying the transport of contaminants to groundwater. The value this depends on various factors, including kind (homogeneous or heterogeneous), flow velocity, initial contaminant concentration, travel distance, and sampling method. A physical model with dimensions 0.10 m width, 0.80 height, 1.10 length was const...

Groundwater and river-water have a different composition and interact in and below the riverbed. The riverbed-aquifer flux interactions have received growing interest because of their role in the exchange and transformation of nutrients and pollutants between rivers and the aquifer. In this research our main purpose is to identify the physical processes and characteristics needed for a numerica...

The age of ground water in any given sample is a distributed quantity representing distributed provenance (in space and time) of the water. Conventional analysis of tracers such as unstable isotopes or anthropogenic chemical species gives discrete or binary measures of the presence of water of a given age. Modeled ground water age distributions provide a continuous measure of contributions from...

Laboratory and field experiments have shown that dispersivity is one of the key parameters in contaminant transport in porous media and varies with elapsed time. This time-dependence can be shown using a time-variable dispersivity function. The advantage of this function as opposed to constant dispersivity is that it has at least two coefficients that increase the accuracy of the dispersivity p...