ABSTRACT
The solution of boundary and initial value problems describing physically based models by use of numerical techniques and computers is known as digital simulation [2.53]. The study of migration processes relies upon digital simulation even more heavily than the study of flow processes because electric analog models can rarely be counted as useful tools in solving migration problems. Likewise, analog-digital or hybrid techniques are of little importance in this area [2.45]. Therefore, digital simulation and the analytical techniques introduced in Chapter 2.1 are the only practical methods for solving migration problems.
