Tissa H. Illangasekare

AMAX Distinguished Chair of Environmental Sciences
Professor, Civil and Environmental Engineering
Director, Center for the Experimental Study of Subsurface Environmental Processes

Illangasekare’s primary area of research is in modeling of flow and transport in permeable and fractured media. His research encompasses many areas that include numerical modeling of saturated and unsaturated flow in soils, surface-subsurface interaction, arid-zone hydrology, integrated hydrologic modeling, flow in subfreezing snow, transport of dissolved and multiphase wastes, wireless sensor networking for environmental monitoring and intelligent remediation and environmental impacts of energy development. His research combines basic theories describing fundamental processes, numerical models and experiments that are conducted at a hierarchy of scales from small laboratory cells to intermediate scale test systems that includes a coupled porous media/ low velocity boundary layer environmental wind tunnel.


His early research on stream-aquifer interactions helped to develop conjunctive use management models for a number of river basins in Colorado. The models he has developed to simulate both laminar and turbulent flow in fractured media have been used in the dam safety analysis. His research on water infiltration in sub-freezing snow has led to the development of models to predict meltwater  generation in arctic glaciers including the Greenland to predict future sea level change. His fundamental research on flow and entrapment behavior of organic chemical wastes and petroleum products and mass transfer under both natural and remedial action has contributed to improve conceptual models that have lead to develop better models, characterization methods, monitoring schemes, up-scaling methods and remediation design. He has extended his research into looking at emerging problems in a shallow subsurface, the zone of the unsaturated zone just below the ground surface bounded by the atmospheric boundary layer. This research will help to address problems in buried threat detection, CO2 sequestration, and land-atmospheric interaction modeling. In humanitarian engineering, he has worked on contamination of coastal aquifers from the 2004 Sumatra tsunami and, more recently, on water quality implications in chronic kidney disease of unknown etiology (CKDu) in Sri Lanka, India, and South America.


Coolbaugh Hall 307


  • PhD in Civil Engineering, Colorado State University, 1978 Colorado State University, Fort Collins, Colorado
  • MEng in Hydrology and Water Resources Engineering, 1974 Asian Institute of Technology, Bangkok, Thailand
  • BSc (honors) in Civil Engineering, 1971 University of Ceylon, Peradeniya, Sri Lanka
  • Honorary Doctorate in Science and Technology, Uppsala University, Sweden, 2010

Professional Registration

  • Registered Professional Engineer in Colorado
  • Registered Professional Hydrologist – American Institute of Hydrology
  • Board Certified Environmental Engineer – American Academy of Environmental Engineers (selected by eminence) – BCEE
  • Diplomate, American Academy of Water Resources Engineering (ASCE/EWRI) – DWRE

Activities and Service

  • Section Chief Editor of Water and Human Health of Frontiers in Water (2020-date)
  • Editor, American Geosciences Union’s “Advances” (2019-date)
  • Editor, American Geosciences Union’s “Perspectives in Earth and Planetary Sciences” (2019-date)
  • Nuclear Waste Technical Review Board (NWTRB) (2017-date)
  • Past Associate Editor of J. of Hydrology, J. of Contaminant Hydrology, and J. of Environmental Fluid Mechanic
  • President – International Society for Porous Media (2017-2019)
  • Board of Trustees of the Consortium of Universities for Advancement of Hydrologic Sciences (CUAHSI).
  • Faculty Trustee, BOT of Colorado School of Mines (2013-2015)
  • National Academy of Science Board on Nuclear Radiation Studies Board (2014-2020)
  • Chair of Gordon Research Conference on Flow and Transport in Permeable Media (2012)
  • Past Editor, Water Resources Research (2009-2013)
  • Past co-editor, Vadose Zone Journal (2006-2009)
  • Editor (hydrology), Earth Science Review (2004 -2009)


Affiliated Appointments

  • Research Affiliate, Energy Geosciences Division, Lawrence Berkeley, National Laboratory Berkeley (LBNL)
  • Visiting Scholar, School of Civil & Environmental Engineering, University of New South Wales, Sydney, Australia (UNSW)

Selected Publications

  • Askar, AH, TH Illangasekare, A Trautz, J Solovský, Y Zhang, R Fučík, 2021. Exploring the Impacts of Source Condition Uncertainties on Far‐Field Brine Leakage Plume Predictions in Geologic Storage of CO2: Integrating Intermediate‐Scale, Water Resources Research 57 (9), e2021WR029679
  • Illangasekare, T.H., Q.Han and A. Jayasumana, “Environmental underground sensing and monitoring” in Underground Sensing: Monitoring for Environment and Infrastructure, (Eds. Pamukcu and Cheng), Elsevier, 2017, ISBN 978-0-12-803139-1
  • Stults, JF.,YJ Choi, CE Schaefer, TH Illangasekare… 2022. Estimation of Transport Parameters of Perfluoroalkyl Acids (PFAAs) in Unsaturated Porous Media: Critical Experimental and Modeling Improvements, – Environmental Science & Technology, 2022
  • Stults, J., T. Illangasekare, C P.Higgins, 2021.  The Mass Transfer Index (MTI): A semi-empirical approach for quantifying transport of solutes in variably saturated porous media, Journal of Contaminant Hydrology,  Volume 242, October 2021, 103842
  • Trautz, A.C., Illangasekare, T.H. and Rodriguez-Iturbe, I. (2017) Role of co-occurring competition and facilitation in plant spacing hydrodynamics in water-limited environments. Proceedings of the National Academy of Sciences (PNAS) of the United States of America 114(35), 9379-9384.

Awards and Honors

  • Elected a foreign member of Academia Europaea (the Academy of Europe) (2022)
  • Lifetime Award, Sri Lanka Foundation- International (2022)
  • Fellow of National Academy of Science of Sri Lanka (2017)
  • Distinguished Alumni Award – Asian Institute of Technology, Thailand (2017)
  • Appointed by President Obama to the Nuclear Waste Technology Review Board (2017)
  • PSIPW International Groundwater Prize (awarded at the UN by Secretary General Ban Ki-Moon, 2016)
  • Fellow of the Soil Science Society of America (2015)
  • Langbein Lecture Award by the American Geophysical Union’s Bowie Lectures (2015)
  • Henry Darcy Medalist by the European Geoscience Union (EGU) (2012)
  • Boland Hydrology Award, AGU, Hydrology Days, Colorado State University (2011)
  • Colorado School of Mines Senate Excellence in Research Award (2010)
  • Honorary Doctorate for Science and Technology, Uppsala University, Sweden (2010)
  • Fellow of American Association for Advancement of Science (2007)
  • Fellow of American Society of Civil Engineers (2006)
  • Fellow of American Geophysical Union (2005)