7.1. The Classification ofGroundwater Quality Models
189
Using the flow equation and
Darcy's law
Using the advectiondispersion eq uation
L ___ _
Input parameters P,/l etc.
Solve velocity distribution V
Solve concentration distribution CI
ls the total sim ulated time up?
ls the flow field steady?
FIGURE 7.1. Flow chart for solving advection-dispersion model in the tracer case.
continuity and kinetic equations, the mean velocity distribution will depend
on concentration distribution. Thus, the equations of the hydrodynamic dispersion system must be solved simultaneously. The iteration method for this
ca se is described as folIows: assume that the solution at time t has been
obtained, and we want to find the solution at the next time, t + At. We may
estimate the concentration distribution at t + At by an extrapolation method
and use the state equations to calculate the relevant values of p and Jl. These
values of p and Jl are then inserted into the continuity and kinetic equations
to obtain the velocity V. Next, we calculate the coefficients of the advectiondispersion equation using V and solve the advection-dispersion equation to
update the concentration distribution at t + At. Using the new concentration
distribution, we can modify the values of p and Jl. This process is repeated
until the concentration distribution does not change within a certain accu-
189
Using the flow equation and
Darcy's law
Using the advectiondispersion eq uation
L ___ _
Input parameters P,/l etc.
Solve velocity distribution V
Solve concentration distribution CI
ls the total sim ulated time up?
ls the flow field steady?
FIGURE 7.1. Flow chart for solving advection-dispersion model in the tracer case.
continuity and kinetic equations, the mean velocity distribution will depend
on concentration distribution. Thus, the equations of the hydrodynamic dispersion system must be solved simultaneously. The iteration method for this
ca se is described as folIows: assume that the solution at time t has been
obtained, and we want to find the solution at the next time, t + At. We may
estimate the concentration distribution at t + At by an extrapolation method
and use the state equations to calculate the relevant values of p and Jl. These
values of p and Jl are then inserted into the continuity and kinetic equations
to obtain the velocity V. Next, we calculate the coefficients of the advectiondispersion equation using V and solve the advection-dispersion equation to
update the concentration distribution at t + At. Using the new concentration
distribution, we can modify the values of p and Jl. This process is repeated
until the concentration distribution does not change within a certain accu-