Time domain reflectometry (TDR) is rapidly becoming a popular method for measuring solute concentrations in the laboratory as well as in the field. Success or failure of TDR to represent solute resident concentrations depends on the accuracy of the invoked calibration. In this study, we compared three commonly used calibration methods that relate the impedance, Z+ as measured with TDR, to the s...

Soil-water flow velocity can be a major factor affecting ion movement in the soil matrix. The transport of both cations and anions and their interactions with soil surface affect many aspects of soil management such as wastewater disposal, saline soil reclamation, remediation of sodic soils, and soil decontamination (HENG et al., 1999a). Therefore it is important to understand the processes tha...

determination of the best method to estimate the dispersion rate is very important to ensure accuracy of the computed data. the aim of this research is studying of transport length effects of dispersion of conservative tracer nacl in soils with different texture using several solute transport models including brigham, fried-combernous and solutions of the advection-dispersion equation with inve...

Soil permeability and soil salinity are considered the most important elements affecting agriculture in arid areas. To analyze and visualize solute transport and soil salinity distribution mechanisms, dye tracer and an electromagnetic device (W.E.T Probe) were used. The purpose of this study is to investigate the effect of separate clayey patches (spots) exist in loamy sand soil on both of soil...

We collected and analyzed breakthrough curve (BTC) data to identify the parameters controlling transport from a series of undisturbed fully saturated soil cores and a field test at the Shale Hills Critical Zone Observatory in central Pennsylvania. The soil cores were collected in a continuous hole extending across the soil profile vertically at one location to quantify how solute transport beha...

242 A dispersion are considered to be the dominant mechanisms of solute transport in the vadose zone, i.e., the variably saturated layer of soils and sediments between the soil surface and groundwater table (Jury and Flühler, 1992). Advection is associated with the average water fl ux or velocity, whereas hydrodynamic dispersion is modeled using an analog of Fick’s law corresponding to the Brow...

[1] The simulation of conservative solute transport in a heterogeneous unsaturated soil depends on the description of spatial variability of soil hydraulic and chemical properties. The data from the Las Cruces Trench Site were used to explore the impact of alternative ways of describing the variability of hydraulic properties. Three different approaches were considered: Miller and Miller scalin...

A classical transport experiment was performed in a field plot of 2.5 m2 using the dye tracer brilliant blue. The measured tracer distribution demonstrates the dominant role of the heterogeneous soil structure for solute transport. As with many other published experiments, this evidences the need of considering the macroscopic structure of soil to predict flow and transport. We combine three di...