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Research Overview

Prof. Craig's interests include the development and application of new modelling approaches for addressing difficult environmental/water resources problems in both groundwater and surface water systems. He and his research group are invested in making these tools and techniques accessible and useful to consultants, educators, and regulators.

When used correctly, environmental models can inform policy makers, increase our understanding of complex systems, and help predict the effects of man's efforts to clean up pollution, use our available water resources, and control climate change. Prof. Craig and his research group work both to improve the science of environmental modelling and, as a nod to basic curiosity-driven research, ambitiously push the boundaries of what is possible using analytical and semi-analytical methods.


Current and Past Research

Upscaling and Robust Modelling of Hydrologic Phenomena
Surface water models are burdened with a difficult task: they are expected to successfully simulate the interaction of a variety of complicated processes (infiltration, evapotranspiration, heat transfer, etc.) at large scales in a computationally efficient manner. To complicate issues, these processes are extremely variable (both in time and space). Prof. Craig and his students are investigating how to use distribution-based approaches to successfully model a variety of phenomenon at mixed spatial and temporal scales. His research group is also working on the development of a robust computational framework, Raven, for assessing the impacts of modelling decisions on model output.
Series Solutions for Regional Groundwater Flow and Particle Tracking
Semi-analytical series solution approaches are an underappreciated and underinvestigated method for simulating a wide range of phenomena in fluid flow, soil, and solid mechanics. The methods can handle complex system geometry without internal discretization, improve with decreasing aspect ratio of the model domain, and provide solutions with near-spectral accuracy. Prof. Craig and his students have developed transient and steady state series solution approaches for multilayer aquifers in multiple dimensions, as well as for mixed saturated/unsaturated flow. We have also developed, in conjunction with partner S.S. Papadopolous & Assoc., series-solution based approaches for resolving particle tracks in MODFLOW-USG's irregular grids.
Analytical Solutions for Flow in Heterogeneous Aquifers
There are very few analytical solution approaches for simulating flow through porous media with heterogeneous properties. Prof. Craig is currently looking into some novel methods based upon Bers-Vekua theory of pseudoanalytic functions to obtain exact solutions to heterogeneous porous media flow problems. These methods may eventually be used to benchmark numerical simulation methods and better understand the impact of heterogenity on pollutant transport.
Mixed Regional and Local Groundwater Flow Modelling
Groundwater flow models are used to improve our understanding of complex aquifer systems to better inform water supply and water quality policy. While existing numerical methods are suitable for simulating large scale systems or local systems, better approaches are needed to integrate the two scales. Prof. Craig is currently addressing this issue via integrating the analytic element method (AEM) which is advantageous at large scales, and the finite element method (FEM), more appropriate for complex local-scale phenomena. He is also working with Dr. Robert Gracie on extension of the extended finite element method (XFEM) to mixed-scale problems of carbon sequestration and reservoir leakage in multilayer aquifer systems.
Improved Design of Horizontal Geothermal Heat Loops
Geothermal is one of the few sustainable energy options that can survive today without government subsidy. However, there is still room for improvement in how we design and install backyard geothermal systems. Many existing systems are overdesigned because we just don’t have a full understanding of heat transport in the subsurface adjacent to the ground loops. The impact of soil variability and ground loop configuration remain elusive, despite the potential impact both can have on long-term performance. With a combination of field and computational research, students Simon Haslam and Richard Simms worked with partner NextEnergy, Inc., attempting to develop a better understanding of the processes which control outdoor loop effectiveness, and determine how we can design more effective systems on smaller land footprints.

Novel Analytical Contaminant Transport Solutions
Analytical solutions for pollutant transport simulation are widely used for preliminary remediation design and analysis, groundwater and atmospheric risk assessment, and regulatory applications. While often useful, critical approximations and assumptions limit their applicability for many investigations and users are forced to rely on more complicated numerical models, which can be cumbersome or inefficient for hypothesis testing. Prof. Craig and his research group work towards extending analytical transport models to be useful in more complex situations with non-uniform flow, complex chemical reactions, and site-specific conditions.
Prospective Research Projects for Graduate, Co-op, and URA Students

There are many project ideas to work on and so little time...

Developing robust numerical and semi-analytical solution methods for simulating:
  • Groundwater-surface water interaction
  • Groundwater flow in smoothly heterogeneous media
  • Complex semi-distributed surface water systems
  • Saturated/unsaturated flow systems
  • Propagation of uncertainty in flow and contaminant transport models
Development of coupled analytical / numerical solution methods:
  • Series solution approaches for regional scale groundwater modelling
  • Mixed analytic element-finite element models for groundwater flow simulation
  • Numerical mapping of analytical contaminant transport solutions to non-uniform flow fields
  • Improved screening models and evaluation methods for capture-zone delineation
Application of numerical models to difficult problems:
  • Sustainability and protection of groundwater-surface water resources
  • Understanding and quantifying regional water balances
  • Understanding the effects of environmental system heterogeneity
...I try to do these all at once. It hasn't worked yet.

Current Graduate Students
  • Erfan Abedian, Ph.D. Candidate
    • M.A.Sc. Structural Engineering, Sharif University of Technology
    • Thesis Topic: Extended finite element modelling of permafrost
  • Élise Devoie, Ph.D. Candidate
    • B.Sc. Mathematical Physics, University of Waterloo
    • Thesis Topic: Fieldwork and modelling in the discontinuous permafrost regions of the southern NWT
  • Rob Chlumsky, M.A.Sc. Student
    • B.Sc. Environmental Engineering (Statistics Option), University of Waterloo
    • Thesis Topic: Rigorous hydrological model assessment and validation in support of decision making
  • Sarah Grass, M.A.Sc. Student
    • B.Sc. Civil Engineering, University of Alberta
    • Thesis Topic: Modelling wetland systems in British Columbia and Alberta
  • Konhee Lee, M.A.Sc. Student
    • B.Sc. Environmental Engineering, University of Waterloo
    • Thesis Topic: Evaluating hydrological model decisions
  • Dan Princz, M.A.Sc. Student (Co-supervised with Prof. Ric Soulis)
    • B.Sc. Environmental Engineering, University of Waterloo
    • Thesis Title: "Using a model evaluation workflow to investigate the influence of parameter granularity in surface water models"

At our geoexchange monitoring site during system installation. Guelph, Nov 2010.
Left to Right: Richard Simms, James Craig, Dave Broderecht (from NextEnergy), Simon Haslam

Computational hydrology researchers pretending to be field savvy. Yukon, Nov 2008.
Left to Right: Lucy Liu, Angela MacLean, Andy Snowdon, Frank Seglenieks, James Craig;
Bottom: Carol Soulis, Kaitlyn McIntyre, Bryan Tolson

Me posing with a three-dimensional groundwater analog model at the Illinois Water Survey HQ, June 2012.
Each node of the 'computational' grid was soldered together by hand, yet even back in 1964 they managed to use multigrid methods, variable pumping rates, and flexible far-field conditions. It just took a bit longer. This is is just about one of the only tangible historical artifacts in the field of groundwater modelling.

Former Graduate Students
  • Ali Ameli, Ph.D.
    • Thesis Title: "Semi-analytical methods for simulating the groundwater-surface water interface"
  • Lucy (Guoxiang) Liu, Ph.D. (Co-supervised with Prof. Ric Soulis)
    • Thesis Title: "Improved interflow and infiltration algorithms for distributed hydrological models"
  • Tussanee Nettasana, Ph.D. (Co-supervised with Prof. Bryan Tolson)
    • Thesis Title: "Conceptual model uncertainty in the management of the Chi River Basin, Thailand"
  • Andy Snowdon, Ph.D.
    • Thesis Title: "Upscaling of coupled models with topography-driven surface-water/groundwater interactions"
  • Mashrur Chowdhury, M.A.Sc.
  • Cameron Dunning, M.A.Sc. (Co-supervised with Prof. Ric Soulis)
    • Thesis Title : "Hydrological modeling of the Upper South Saskatchewan River basin: Multi-basin calibration and gauge de-clustering analysis"
  • Simon Haslam, M.A.Sc.
    • Thesis Title: "Informing the practice of ground heat exchanger design through numerical simulations"
  • Chao Huo, M.A.Sc. (Co-supervised with Prof. Neil Thomson)
    • Thesis Title : "Mathematical simulation of a dipole delivery system for in situ remediation"
  • Erin L. Jones, M.A.Sc. [Joint with Biology] (Co-supervised with Prof. Ralph Smith)
    • Thesis Title: "Ecological modelling of Lake Erie : Sensitivity analysis and simulation of nutrient, phytoplankton, and zooplankton dynamics"
  • Muhammad Ramadhan, M.A.Sc.
    • Thesis Title: “A semi-analytical particle tracking algorithm for arbitrary unstructured grids”
  • Philip Sheffield, M.A.Sc.
    • Thesis Title: "The utility of using multiple conceptual models for the design of groundwater remediation systems"
  • Richard Simms,M.A.Sc.
    • Thesis Title: "The effects of soil heterogeneity on the performance of horizontal ground loop heat exchangers"
  • Nicholas Sgro, M.A.Sc.
  • Andy Snowdon, M.A.Sc.
    • Thesis Title: "Improved numerical methods for distributed hydrological models"