The objectives of this study were to: (i) examine the efficacy of two sampling techniques for characterizing solute transport under steady-state water flow, (ii) study the variation in transport model parameters with increasing depth of solute leaching, and (iii) perform model discrimination to examine the transport process operative within a field plot. Bromide, NO?, and Clwere applied sequent...

The effect of gypsum on the physical and chemical characteristics of sodic soils is nonlinear and controlled by multiple factors. The support vector machine (SVM) is able to solve practical problems such as small samples, nonlinearity, high dimensions, and local minima points. This paper reports the use of the SVM regression method to predict changes in the chemical properties of sodic soils un...

The purpose of this model is to enable implementation of the theory of linear systems control in operational management of waste and fertiliser applications onto land, so that the underlying groundwater is protected from pollution by leachate. The state-space form of the model enables use of the extensive theory and available software on stochastic linear S)lstCms. In particular, the Kalman fil...

Modeling the contaminant transport process in soils requires the solute transport parameters. Displacement experiments were carried out on soil columns (Sand – Silt – Clay) by injecting a solution of 0.8 M KCl in a steady state. Breakthrough curves are symmetrical, characteristics of an equilibrium solute transport. The hydrodynamic dispersion coefficients were estimated by optimizing the measu...

the partial differential equations for water flow and solute transport in a two-dimensional saturated domain are rendered discrete using the finite difference technique; the resulting system of algebraic equations is solved using a dynamic programming (dp) method. the advantage of the dp algorithm is that the problem is converted from solving an algebraic system of order nc(nl-1) nc(nl-1) into...

introduction: preferential flow is one of the major processes influencing the rapid movement of pollutants to ground water.  macropores created by plant roots provide pathways for rapid transport of pollutants in a soil profile. the growth of plant roots into soil causes creation of big pores that improve water movement and solute transport through soil profile. field soils or undisturbed soils...

It is well known that there is a spectrum of pores in a soil profile. The conventional use of a single lumped value of soil hydraulic conductivity to describe a spectrum of hydraulically active pores may have unintentionally impeded the development of field-scale chemical transport theoryand perhaps indirectly hindered the development ofmanagement protocols for chemical application andwaste dis...