DESCRIPTION OF COURSES

Close

AP 612 ADVANCE SOIL PHYSICS I - SOIL WATER AND NUTRIENT TRANSPORT                                                                                 (3L+1P) II
(Pre-requisite: AP 110 & AP 104)

Objective
  To study the physical processes for transport of water and nutrients in soil.

Theory

UNIT I
  Soil water transport: saturated flow equations: Poiseuille’s and Darcy’s equations, Laplace equation of steady flow and unsteady flow equation and their solutions, three dimensional saturated hydraulic conductivity and fluxes, hydraulic conductivity for layered soil, conductance coefficient, unsaturated flow equations: Buckinghum-Darcy equation, Richards equation, dynamics of water flow, stationary water flux, diffusivity, Boltzmann transformation and a wetting front, unsaturated hydraulic conductivity, Infiltration, profile controlled and supply controlled infiltration, horizontal infiltration, vertical infiltration, Green-Ampt model, Philip model, homogeneous and layered soil infiltration, curve number method, preferential flow, measurement of unsaturated hydraulic conductivity: lab methods: direct method - constant head and falling head methods; indirect method- parameterization of hydraulic functions. Field methods- infiltrometers and permeameters, instantaneous profile and field inverse methods. Numerical models of water flow, finite element and finite difference methods

UNIT II
  Root water uptake modeling: computation of root water uptake using Richard’s equation; Ritchie’s root water uptake model.

UNIT III
  Solute transport: solute transport mechanisms: mass flow, diffusion, hydrodynamic dispersion, miscible and immiscible displacement, hypothetical and experimental breakthrough curves, Convective-Diffusive equation (CDE), linear and non-linear adsorption, solution of CDE, analytical solution by variable transformation and Laplace transformation, numerical solutions by finite difference and finite element methods, applications, methods of determination of dispersion and diffusion coefficients.

Practicals
  Guelph Permeameter for field saturated hydraulic conductivity, Hydraulic conductivity by instantaneous profile method, Computation of dispersion and diffusion coefficients of CDE, Computation of solute (nonreactive) distribution in profile by analytically solving solute transport equation under different initial and boundary conditions

Suggested Reading