**Author details**

**6. Conclusions**

The primary focus of this study was unsaturated soils. The most important specific concepts related to this subject were detailed with the goal of enabling their application with the aid of

Several of the concluding comments and recommendations derived from the analysis of the

**•** When specialized laboratory results are unavailable (to describe variations in water content and permeability with respect to suction), the unsaturated soil property functions required

**•** For the correct estimation of unsaturated soil property functions (soil-water characteristic curve and hydraulic conductivity function), a large amount of laboratory data can be required, specifically, results from different index properties, grain-size distribution curve,

**•** To determine the appropriate unsaturated soil property functions (soil-water characteristic curve and hydraulic conductivity function) for the calculations in analyses performed here, the form and tendency of the soil curves were considered. However, it is possible to use statistical methods to define these functions. Certain programs will perform these calcula‐

**•** For numerical modelling that considers materials with high contrast in permeability by orders of magnitude, for example, it is common for numerical difficulties to be presented. To resolve this type of problems, highly permeable materials that do not contribute to the dissipation of the hydraulic head can be omitted; however, as a consequence, these will not have an effect in the final resolution of the model. If the material must be considered in calculations, then it can be substituted by gravel to facilitate the convergence of the model. To obtain satisfactory results, an adequate definition of the SWCC is necessary in addition to the hydraulic conductivity functions, which will be necessary to obtain representative solutions. Despite this, numerical complications may be present, which can only be reduced with convergence parameters, or in this case, by step-by-step analysis until an optimal

**•** Depending on the problem to be analysed and its complexity, more detailed discretizations may be required to decrease the numerical error of calculations. This approach should not be confused with the automatic generation of a dense finite element mesh because for many water flow models, the use of such discretizations is not justified and will only affect

**•** Water infiltration plays an important role in the stability of deposits of mining wastes (tailing dams), and it is appropriate to consider water movement in these calculations to better understand its behaviour. Therefore, the benefits of numerical modelling are numerous because these methods allow for diverse situations, given relatively short periods of analysis, to be considered, thereby informing and enabling appropriate decision-making.

calculation times without leading to improvements in the solution of the problem.

specialized computer programs based on the finite element method.

for the analysis can be determined by estimation methods.

case study in this chapter are detailed as follows:

186 Groundwater - Contaminant and Resource Management

and soil permeability experiments.

tions (such as SoilVision Database).

solution is achieved.

Norma Patricia López-Acosta\* and José Alfredo Mendoza-Promotor

\*Address all correspondence to: nlopeza@iingen.unam.mx

Institute of Engineering, Nacional University of Mexico (UNAM), Mexico City, Mexico
