12.05 Uncertainties due to boundary conditions in predicting mixing in groundwater (UNMIX)

Research

In many practical relevant situations, we are interested in modelling the fate and transport of contaminants close to the boundary conditions of a computational domain (e.g., a contaminant ground-water plume endangering a well or a surface water body, saltwater intruding in coastal aquifers,…). Modelling the dynamic behaviour of such boundary conditions is complex and is a major source of uncertainty for model prediction. In this work, we aim at investigating the impacts of extreme hydrological conditions (e.g., floods, droughts, storm surge) in controlling groundwater flow boundary conditions and consequently mixing processes in the subsurface. The correct quantification of mixing is in fact of utmost importance for modelling conservative and reactive transport in aquifers. While major efforts have been spent to assess the effect on mixing of heterogeneous flow fields typical of natural geological structures, less attention has been payed to mixing occurring at the transient boundary of a groundwater model. First, we will focus on synthetic simulations to investigate the role of extreme hydrological conditions on dilution and reactive mixing enhancement applying the dilution index both in its classical and flux related forms. Then, we will apply a newly developed measure theory to derive model parameters (e.g., dispersion coefficients, flow velocity, contaminant source location) and quantify model uncertainty due to the uncertain boundary conditions. Finally, we will apply the newly developed tools to assess four real case studies in which the boundary conditions play a fundamental role for the quantification of mixing processes in the subsurface.

Publications

Research articles
Bittner, D., Narany, T. S., Kohl, B., Disse, M., & Chiogna, G. (2018). Modeling the hydrological impact of land use change in a dolomite-dominated karst system. Journal of Hydrology, 567, 267-279. doi: 10.1016/j.jhydrol.2018.10.017

Merchan-Rivera, P., Chiogna, G., Disse, M., & Bhola, P. (2018). Surface water and groundwater interaction during flood events in the Alz Valley: numerical modeling and solute transport simulations. El agua subterránea : recursos sin fronteras. ISBN: 978-987-633-536-2

Preprints 
Bittner, D., Teixeira Parente, M., Mattis, S., Wohlmuth, B., & Chiogna, G. (2018). On the relationship between parameters and discharge data for a lumped karst aquifer model. arxiv.org

Conference contributions
Bittner, D., Disse, M., Sheikhy, T., & Chiogna, G. (2018). Modelling the impact of land use change on drinking water supply in a karstic system. In EGU General Assembly Conference Abstracts (Vol. 20, p. 6151).

Chiogna, G., Ye, Y., Lu, C., & Rolle, M. (2018). Effect of anisotropy structure on plume dilution and reaction enhancement in helical flows. CMWR 2018 conference.
Mattis, S., & Wohlmuth, B. (2018). Goal-Oriented Surrogate Construction for Groundwater Problems. CMWR 2018 conference.

Merchan-Rivera, P., Chiogna, G., Disse, M., & Bhola, P. (2018). Interacción entre agua superficial y agua subterránea durante eventos de inundación: modelización numérica y simulaciones de transporte de solutos. X Congresso Argentino de Hidrogeologia y XIV Congreso Latinamericano de  Hidrogeologia.

Posters
Basilio Hazas, M. & Chiogna, G. (2018). Impact of hydropeaking on groundwater flow and transport: a case study in the Adige Valley. 4th Cargèse Summer School on "Flow and Transport in Porous and Fractured media: Development, Protection, Management and Sequestration of Subsurface Fluids"

Team

Project team leader

Dr. Gabriele Chiogna
Chair of Hydrology and River Basin Management

Doctoral researcher

Monica Basilio Hazas
Chair of Hydrology and River Basin Management

Doctoral researcher

Mario Parente
Chair of Numerical Analysis

Doctoral researcher

Daniel Bittner
Chair of Hydrology and River Basin Management

Doctoral researcher

Pablo Merchan Rivera
Chair of Hydrology and River Basin Management

Principal investigator

Professor Markus Disse
Chair of Hydrology and River Basin Management

Principal investigator

Dr. Steven Mattis
Chair of Numerical Analysis

Principal investigator

Dr. Jorge Eduardo Teixeira Leandro
Chair of Hydrology and River Basin Management