Checking simulations of a geolithological model obtained by means of nested truncated bigaussian method

Characterizing the spatial distribution of major lithotypes and their relationships is a key aspect in the process of hydrogeological modeling of aquifers in that assignment of lithotypes-specific hydraulic and hydrochemical properties requires the knowledge of the layout of the lithotypes themselves. Truncated bigaussian simulation is a procedure derived from the truncated Gaussian model, used to simulate random sets, and, in particular, variable geological characteristics, expressed as categorical variables. Anyway, in cases of many lithotypes having not homogeneous spatial behaviors, this methodology might not explain at best the relations existing among the lithotypes themselves; a more general method is therefore required to represent this variability. In this paper, that concerns a site whose geologic asset has already been reconstructed, in order to better characterize the aquifer geolithological architecture, nested simulation for a macro-unit of the previously realized geolithologic model has been carried out, together with a check phase of the results obtained by the mentioned simulation. The proposed methodology can represent a useful instrument for the modeling of complex geological layouts other than in the detailed characterizations of hydrogeological studies, for a better interpretation of the complex phenomena that take place in groundwater circulation and contaminant propagation.