Solute transport in different geological scenarios generated by stochastic model of Markov chains

Abstract

The understanding of subsurface contaminants behavior is critical for the quantification of human health risk and planning of active remediation. Since the prediction reliability of plume behavior is related to lithological variability in subsurface, there is a high degree of uncertainties in heterogeneous aquifers. In order to investigate the effect of observed heterogeneity of Rio Claro Aquifer, located in the municipality of Paulínia(SP), on the fate and transport of dissolved contaminants in groundwater, simulations encompassing different geological scenarios was carried out. Based on lithological information from 58 survey description, 10 different geological scenarios were generated using the stochastic model of Markov Chain. Each geological scenario was reproduced into numerical models to evaluate the transport of contaminants dissolved in groundwater. The results indicate wide variability of the dimensions and migration directions of the dissolved plumes. The main factor responsible for such variation is the degree of connectivity of sandy bodies with high permeability. These results suggest that uncertainties are intrinsically related to the sandy bodies connectivity, hampering the prediction of contaminant plumes migration and the planning of the remediation systems in similar aquifers to Rio Claro.

Keywords

• Heterogeneidade geológica. Modelos estocásticos. Conectividade entre corpos arenosos.