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Dr Dirk Mallants

Senior Principal Research Scientist


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Dr Mallants has a background in soil and groundwater hydrology with more than 30 years of experience in characterising and modelling water flow and contaminant transport in complex environments – typically variably-saturated soils, aquifers and low-permeable porous media including clay aquitards and man-made materials such as concretes. He specialises in whole-of-system understanding by integrating experimental observations and coupled numerical models.

His work includes parameterisation of pore-scale and field-scale spatial variability in flow and transport properties, modelling processes of water flow and contaminant transport across a range of spatial scales, and the evaluation by means of process-based models of management options for water-related environmental pollution problems.

Dr Mallants has 30 years of research experience in water flow and chemical transport measurement and modelling in soil-groundwater systems.

He has researched interactions between hydrocarbon extraction (unconventional gas) and water resources, geological disposal of radioactive waste in deep rocks, and the impact of irrigation with recycled water on soil and crop health.

In the mid-1990s he contributed to improvement in analysis of Time Domain Reflectometry data for solute transport applications and salinity monitoring in soil.

Dr Mallants has also been involved with front-end and back-end (human health and environmental) impact assessment studies for the nuclear fuel cycle in Europe (Belgium, Bulgaria, Hungary, Romania, Russia, Slovak Republic, Slovenia), South-America (Argentina), and Asia (China, Indonesia, Kyrgyzstan, Malaysia, The Philippines). Through his career he has been supporting numerous waste management agencies with site selection, safety assessment, and development of a safety case for surface and deep repositories of low level radioactive and high level nuclear waste.

His engagement with community partnerships as part of a long-term nuclear repository development programme was described in the March 2013 issue of ECOS Magazine:

"Successful examples of public participation also exist in community partnerships around nuclear repository programs in Europe, Canada and Asia. The search for suitable sites for radioactive waste disposal has a history of conflicts, delays, and sometimes failure. In response, waste management institutions have progressively turned away from the traditional one-way flow of information and are now embracing the ‘engage-interact-cooperate’ approach with opportunity for feedback and negotiation. This shift has fostered the emergence of sound partnerships between the proponents of disposal facilities and potential host communities."

Under the auspices of the International Atomic Energy Agency (IAEA), he has lectured dozens of training courses on subsurface characterisation, site evaluation and remediation, and safety assessments for wastes associated with the nuclear fuel cycle including tailings from mining and milling.

Recent advancements were made in the field of:
• coupled reactive transport modelling for variably-saturated media using the coupled Hydrus-PHREEQC
biogeochemical transport simulators
• climate change impacts on the hydrological cycle for temperate oceanic climates
• natural analogues for studying long-term evolution of recent and anthropic soils
• geophysical/geotechnical techniques (cone penetration testing) to determine subsurface spatial variability in
stratigraphy (layering) and hydrogeological parameters
• efficient calibration of high-dimensional groundwater models
• reactive transport modelling of soil salinity to support devising improved guidelines for the sustainable use of
recycled water for irrigated agriculture.
• use of noble gas isotopes for quantifying how long rock fluids have been isolated from the hydrological cycle.

He was previously Project Leader for Low-Level Radioactive Waste Disposal and Environmental Studies and Head of the Performance Assessments Unit at the Belgian Nuclear Research Centre, SCK•CEN.

Dr Mallants graduated as geo-environmental engineer (soil physics) at the Faculty of Agricultural and Applied Biological Sciences of the Catholic University of Leuven (KUL), Belgium.

In 1996 he obtained a Doctor of Philosophy (PhD) in soil physics also from the KUL.

Part of his PhD research on water flow and contaminant transport in a heterogeneous soil profile was accomplished at the United States Salinity Laboratory in Riverside California, in collaboration with Dr. Martinus van Genuchten and Dr. Jirka Simunek.

Current Roles

  • Professor (Full Academic Status - Level E)
    Flinders University of South Australia

Academic Qualifications

  • 1996

    Katholieke Universiteit Leuven (Belgium)

Achievements and Awards

  • 2023-2025

    Medium Infrastructure Program
    Science and Industry Endowment Fund

  • 2018-2020

    Medium Infrastructure Program
    Science and Industry Endowment Fund

  • 2016-2016

    Nuclear Fuel Cycle Community & Response Agency - Australasian Best Project of the Year
    International Association for Public Participation

  • 2016-2016

    Sir Frederick McMaster Fellowship for Professor Jirka Simunek

  • 2014-2014

    OCE Cutting Edge Science Symposium "Critical Zones"

  • 2012-2012

    Sir Frederick McMaster Fellowship for Professor Jasper Vrugt


  • 01/04/1996-30/09/1996

    Japan Society for the Promotion of Science

Community and Corporate Citizenship

  • 31/10/2013-31/12/2016

    Australian Research Council College of Experts

  • 2014-2019

    Research Advisory Committee member for the Goyder Institute for Water Research

  • 2017-2021

    Independent Assessor for NZ Ministry of Business, Innovation and Employment

  • 2000-2002

    Associate Editor Journal of Environmental Quality

  • 2012-2014

    Associate Editor Vadose Zone Journal

  • 2013-2015

    American Society of Agronomy - Associate Editor Soils

  • 2012-2013

    Associate Editor Journal of Hydrology and Hydrodynamics