An Analysis Platform for Multiscale Hydrogeologic Modeling with Emphasis on Hybrid Multiscale Methods

Abstract

One of the most significant challenges faced by hydrogeologic modelers is the disparity between the spatial and temporal scales at which fundamental flow, transport, and reaction processes can best be understood and quantified (e.g., microscopic to pore scales and seconds to days) and at which practical model predictions are needed (e.g., plume to aquifer scales and years to centuries). While the multiscale nature of hydrogeologic problems is widely recognized, technological limitations in computation and characterization restrict most practical modeling efforts to fairly coarse representations of heterogeneous properties and processes. For some modern problems, the necessary level of simplification is such that model parameters may lose physical meaning and model predictive ability is questionable for any conditions other than those to which the model was calibrated. Recently, there has been broad interest across a wide range of scientific and engineering disciplines in simulation approaches that more rigorously account for the multiscale nature of systems of interest. In this article, we review a number of such approaches and propose a classification scheme for defining different types of multiscale simulation methods and those classes of problems to which they are most applicable. Our classification scheme is presented in terms of a flowchart (Multiscale Analysis Platform), and defines several different motifs of multiscale simulation. Within each motif, the member methods are reviewed and example applications are discussed. We focus attention on hybrid multiscale methods, in which two or more models with different physics described at fundamentally different scales are directly coupled within a single simulation. Very recently these methods have begun to be applied to groundwater flow and transport simulations, and we discuss these applications in the context of our classification scheme. As computational and characterization capabilities continue to improve, we envision that hybrid multiscale modeling will become more common and also a viable alternative to conventional single-scale models in the near future.

Towards an integrated understanding of how micro scale processes shape groundwater ecosystem functions

“…Even though first attempts have been made at coupling micro scale evaluations to catchment scale estimations (Battiato et al, 2011;Scheibe et al, 2015a), these attempts are restricted to bacterial microorganisms so far (see also section 4.3). However, it has been known for decades that protozoan grazing either reduces (Kota et al, 1999) or advances (Mattison et al, 2005) bacterial biodegradation, even under groundwater conditions.…”

“…Micro scale models have been coupled to larger scale models by Tartakovsky et al (2013) whose genome-scale model was used to predict biomass yield and stoichiometry for iron consumption, in comparison to prior Monod formulations based on energetics considerations", by who upscaled microbially induced calcite precipitation, by Orgogozo et al (2013) who developed an approach to Stokes type solute transport in an unconsolidated medium with biofilm growth combined with a quasi-steady linear closure for the bioreactions, and by Scheibe and colleagues (Scheibe et al, 2015a(Scheibe et al, , 2015b(Scheibe et al, , 2015c who developed a general framework. In Scheibe et al (2015c) and Scheibe et al (2015a) reactivity is modelled along interfaces. However, none of these approaches tackles the discontinuous biological growth patterns at the same time.…”

Lattice Boltzmann-Based Approaches for Pore-Scale Reactive Transport

“…However, the ultimate goal is to improve predictive capability at larger continuum and fi eld scales. As conventional homogenization and volume-averaging techniques are not valid due to process nonlinearity and the lack of scale separation, pore-scale modeling is enabling new methods of upscaling, including multiscale, multi-physics approaches (Chu et al 2013;Tomin and Lunati 2013;Varloteaux et al 2013;Scheibe et al 2015). A key assumption of the methods reviewed here is that all processes as well as the pore geometry can be quantifi ed unambiguously at the smallest scale (i.e., pore scale).…”

Hybrid multiscale simulation of a mixing-controlled reaction

“…Scheibe et al [70] provide a review of hybrid multiscale simulation methods and their applications in a number of scientific domains including recent developments in modeling of reactive transport in porous and fractured media. Tartakovsky and Scheibe [71] demonstrated an approach for coupling continuum-and pore-scale models applied to a mixingcontrolled precipitation reaction over a small (mm-scale) domain.…”