Solute Transport in Hierarchical Sediments

Which characteristics of solute transport behaviour in heterogeneous porous media are lost by neglecting geological realism?

PhD Researcher: Jeremy Bennett
Supervisors: Olaf Cirpka (University of Tübingen), Claus Haslauer (University of Tübingen), Martin Ross (University of Waterloo)

PhD Thesis

Motivation

Many advances in the numerical modelling of three-dimensional groundwater flow and solute transport have been implemented in porous media structures that do not adequately represent deposits observed in the field. The main goal of this PhD project is to determine which characteristics of solute transport in heterogeneous media are lost by neglecting geological realism. This project focuses on hierarchical sedimentary deposits, units of which can be defined across multiple scales, with larger-scale units composed of assemblages of smaller-scale units. Methods and expertise from the fields of sedimentary geology and quantitative hydrogeology will be combined to achieve the research objectives.

Research objektives

Three research objectives provide a framework for this PhD project:

To investigate how variability in geological processes affects solute transport in sedimentary aquifers.
To build geologically plausible hierarchical facies models and assess their ability to replicate typically observed solute transport behaviour.
To explore how knowledge of geological processes can be used to improve solute transport modelling in practice.

Approach

Figure 1: Streamtubes in scour pool fill features generated using object-based methods.

To investigate how variability in geological processes affects solute transport in sedimentary aquifers, geologically plausible hierarchical facies models will be developed. The ability of these three-dimensional porous media models to replicate typically observed solute transport behaviour will be assessed by conducting groundwater flow and solute transport simulations in these media. Methods for using knowledge of geological processes to improve solute transport modelling in practice will be explored. This research project encompasses many different disciplines in geosciences, including: hydrostratigraphic modelling; groundwater flow and solute transport modelling; and the quantification of flow and transport behaviour.

Publications

Chow, R., Bennett, J.P., Dugge, J., Wöhling, T., Nowak, W. (2019): Evaluating subsurface parameterization to simulate hyporheic exchange: The Steinlach River Test Site. Groundwater, doi: 10.1111/gwat.12884
Bennett, J.P., Haslauer, C. P., Ross, M., Cirpka, O. A. (2018): An Open, Object‐Based Framework for Generating Anisotropy in Sedimentary Subsurface Models. Groundwater, doi: 10.1111/gwat.12803
Chow, R., Wu, H., Bennett, J.P., Dugge, J., Wöhling, T. and Nowak, W. (2018): Sensitivity of simulated hyporheic exchange to river bathymetry: The Steinlach River Test Site. Groundwater. doi: 10.1111/gwat.12816
Bennett, J.P., Haslauer, C. P., Cirpka, O. A. (2017): The Impact of Sedimentary Anisotropy on Solute Mixing in Stacked Scour‐Pool Structures. Water Resources Research, doi: 10.1002/2016WR019665