Uncertainty with Varying Subsurface Permeabilities Reduced Using Coupled Random Field and Extended Theory of Porous Media Contaminant Transport Models

Abstract

To maximize the usefulness of groundwater flow models for the protection of aquifers and abstraction wells, it is necessary to identify and decrease the uncertainty associated with the major parameters such as permeability. To do this, there is a need to develop set of estimates representing subsurface heterogeneity or representative soil permeability estimates. Here, we use a coupled Random Field and extended Theory of Porous Media (eTPM) simulation to develop a robust model with a good predictive ability that reduces uncertainty. The coupled model is then validated with a physical sandbox experiment. Uncertainty is reduced by using 500 realisations of the permeability parameter using the eTPM approach. A multi-layer contaminant transport scenario with varying permeabilities, similar to what could be expected with shallow alluvial sediments, is simulated. The results show that the contaminant arrival time could be strongly affected by random field realizations of permeability compared with a modelled homogenous permeability parameter. The breakthrough time for heterogeneous permeabilities is shorter than the homogeneous condition. Using the 75% confidence interval (CI), the average contaminant concentration shows 4.4% variation from the average values of the considered area and 8.9% variation in the case of a 95% confidence interval.

Simulation of zonation-function relationships in the liver using coupled multiscale models: Application to drug-induced liver injury

“…To describe flow and transport of microscopic substances, we extend this approach to include microscopic solutes in blood and liver tissue. To simulate exchange processes between different components, the TPM has been extended with mass exchange processes for miscible [56, 57] and non-miscible substances [58, 59, 60, 61, 62].…”

Simulation of Contaminant Transport through the Vadose Zone: A Continuum Mechanical Approach within the Framework of the Extended Theory of Porous Media (eTPM)

“…Due to the complexity of phase partitioning and reaction, there are only a few analytical models considering multiple phases and multiple solutes [13,14], multiple solute transport with reactions in multiple phases [15], and combined transient water and solute transport [16]. In order to deal with problems concerning saturated and unsaturated zones, there are different numerical approaches, including the finite difference method (FDM) [17,18], the finite volume method (FVM) [19], the finite element method (FEM) [20,21], and the Meshfree method [22], each of which has various treats that tailor the model to the special application for which it was designed. Rao et al combined explicit finite difference formulations with multiple domain algorithms and developed models for one and two-dimensional transient contaminant transport flow [23,24].…”

“…The Theory of Porous Media (TPM) [31][32][33][34] facilitates a comprehensive continuum mechanical framework based on the Mixture Theory [35], enhanced by the concept of volume fractions, for the simulation of different processes in a saturated or partially saturated medium. Furthermore, it paves the way for the description of geophysical and geochemical environmental problems [18,21,[36][37][38][39][40][41][42].…”

Stability Analysis of Super-Large Special-Shaped Deep Excavation in Coastal Water-Rich Region Considering Spatial Variability of Ground Parameters

“…They also utilized the Monte-Carlo strategy to analyze the influence coefficients of variation in elastic modulus and correlation distances on surface deformation through finite-difference software. Similarly, the random field theory has made outstanding contributions in the measurement of groundwater permeability, mechanical parameters of soft soil and hydrological response [22][23][24].…”