Heterogeneity in real (geological) media leads to complex flow paths, which in turn cause complex  structures in the transport of contaminants. The presence of various flow paths of different flow speeds  causes greater spreading of plumes, which in turn affects arrival times, maximum concentrations, mixing  and chemical reactions.

This heterogeneity typically occurs at a multitude of scales, many of which would require resolution well  beyond our current capacity for the correct numerical simulation of flow and transport phenomena. As  such the accurate quantification of uncertainty and the development of simplified models that can capture  the influence of heterogeneity is essential for accurate prediction capabilities.

One area we have recently focused on the influence that heterogeneity has on mixing as this is a crucial component in estimating reactive transport. Our work to date has focused on developing analytical  solutions for simple setups of heterogeneity as well as developing theoretical models to predict  uncertainty and mixing. Our work often relies on numerical modeling for validation purposes and  semi-theoretical approaches

Relevant Papers

E Castro, D fernandez-Garcia, J Carrera and D Bolster
Visualization of mixing processes in a heterogeneous sand box aquifer, Environmental Science and Technology, 46 (6), pp 3228–3235

D Bolster and M Dentz
Anomalous Dispersion in Chemically Heterogeneous Media induced by Long Range Correlations, Journal of Fluid Mechanics, Volume 695, pp 366 - 389

M Dentz, D Bolster
Distribution- versus correlation-induced anomalous transport in quenched random velocity fields
Physical Review Letters, 105, 244301

T Le Borgne, M Dentz, D Bolster, J Carrera, J-R de Dreuzy and P Davy
Non-Fickian mixing: temporal evolution of the scalar dissipation rate in porous media
Advances in Water Resources, doi:10.1016/j.advwatres.2010.08.006, Vol 33(12), P1468-1475

Xavier Sanchez-Vila, Diogo Bolster
An Analytical Approach to Transient Homovalent Cation Exchange Problems
Journal of Hydrology, Volume 378, Issues 3-4, 30 November 2009, Pages 281-289

Marco Dentz, Jesus Carrera, Diogo Bolster, Tanguy Le Borgne
Multipoint concentration statistics for transport in stratified random velocity fields
Physical Review E 80, 036306

Dentz Marco, Bolster Diogo and Le Borgne Tanguy (2009)
'Concentration statistics for transport in random media'
Physical Review E 80, 010101

Bolster D., Dentz M., Carrera J (2009)
"Effective Two-Phase flow in heterogeneous media under temporal pressure fluctuations"
Water Resources Research, 45, W05408, doi:10.1029/2008WR007460.

A. M. Tartakovsky, D. Bolster, and D. M. Tartakovsky (2009)
"Identification of Layered Structures of the Vadose Zone from Electrical Resistivity
Surveys"
Vadose Journal , 7, 1253