6
1. Introduction
Flow continuous eq.
+
Movement eq. (Darcy's lawl
+ I
State eq.
+
Advection-Dispersion eq.
+ I Subsidiary conditions
Water quality model
FrGURE 1.1. The constitution of the water quality model on advection-dispersion.
Input
-
Model
-
Output
I
Geometrie shape of the domain
I
1
I
Flow parameters
t
I
Dispersion coemcients
I -
Time~space
I
Wen locations and yields
I-- Water quality model
distribution of
salute concentration
I
Location and intensity of
rcontamination sources
I
Initial condition
• f
I
Boundary condition
FrGURE 1.2. Input and output of the water quality model.
advection model is a simple one, in which the solute transport is assumed to
be completely determined by groundwater flow. On the other hand, as shown
in Figure 1.1, the advection-dispersion model is based on the theory of
hydrodynamic dispersion in porous media. Thus, the dispersion phenomena
must be studied and some new parameters must be introduced for deriving
the advection-dispersion equation. Since the advection-dispersion model of
groundwater quality consists of several partial differential equations, numerical solution techniques must be used.
In order to build a water quality model for an aquifer system, besides the
selection of model structure, various hydrogeological parameters (especially
the dispersion-related ones) appearing in the governing equations and initial
and boundary conditions must be determined. The input and output of a
groundwater quality model is shown in Figure 1.2. Model parameters, as weIl
as boundary conditions, are generally determined by a parameter identification procedure, i.e., using tracer test data and other prior information to
calibrate the model. In a certain sense, the parameter identification problem
is the inverse problem of the prediction problem. As shown in Figure 1.2, the
input and output of the two problems are exchanged.
1. Introduction
Flow continuous eq.
+
Movement eq. (Darcy's lawl
+ I
State eq.
+
Advection-Dispersion eq.
+ I Subsidiary conditions
Water quality model
FrGURE 1.1. The constitution of the water quality model on advection-dispersion.
Input
-
Model
-
Output
I
Geometrie shape of the domain
I
1
I
Flow parameters
t
I
Dispersion coemcients
I -
Time~space
I
Wen locations and yields
I-- Water quality model
distribution of
salute concentration
I
Location and intensity of
rcontamination sources
I
Initial condition
• f
I
Boundary condition
FrGURE 1.2. Input and output of the water quality model.
advection model is a simple one, in which the solute transport is assumed to
be completely determined by groundwater flow. On the other hand, as shown
in Figure 1.1, the advection-dispersion model is based on the theory of
hydrodynamic dispersion in porous media. Thus, the dispersion phenomena
must be studied and some new parameters must be introduced for deriving
the advection-dispersion equation. Since the advection-dispersion model of
groundwater quality consists of several partial differential equations, numerical solution techniques must be used.
In order to build a water quality model for an aquifer system, besides the
selection of model structure, various hydrogeological parameters (especially
the dispersion-related ones) appearing in the governing equations and initial
and boundary conditions must be determined. The input and output of a
groundwater quality model is shown in Figure 1.2. Model parameters, as weIl
as boundary conditions, are generally determined by a parameter identification procedure, i.e., using tracer test data and other prior information to
calibrate the model. In a certain sense, the parameter identification problem
is the inverse problem of the prediction problem. As shown in Figure 1.2, the
input and output of the two problems are exchanged.