Improved groundwater modeling by incorporating geological information from hydrogeological sections

Abstract

Geological cross-sections are usually employed in the hydrogeological model conceptualization, but their usage may not be easily exploited in subsequent modeling phases. The spatial distribution of geological facies along a geological section’s track may significantly vary when using random facies fields, and these may not be faithful to the original conceptualization described by the geological section. The present work offers a novel framework for improving available hydrogeological models using geological sections as a more quantitative source of information, hence by taking into account of information coming from a geological section. Then, this information given by the change in the distribution of porosities is transferred from the section’s track to surrounding locations through a proper kriging procedure upon a chosen Correlation Scale (R), which is exponentially correlated in space. This procedure is tested by using porosity distributions upon several R, associating a conductivity value with each porosity one through empirical formulations, and informing several numerical models related to a real case study (an aquifer in the province of Lecco, Northern Italy). The proposed procedure enables to significantly outperform the former calibrated numerical model. Best-calibrated models show that the convenient R could be from 2 to 5 kilometers long, consistent with the width of the alluvial and fluvioglacial floodplain that characterizes the aquifer under examination.