Tissa H. Illangasekare

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

Tissa IllangasekareIllangasekare’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

  • Editor, American Geosciences Union’s “Advances” (2019-date)
  • Editor, American Geosciences Union’s “Perspectives in Earth and Planetary Sciences” (2019-date)
  • Section Chief Editor of Water and Human Health of Frontiers in Water (2020-date)
  • Past Editor, Water Resources Research (2009-2013)
  • Past co-editor, Vadose Zone Journal (2006-2009)
  • Editor (hydrology), Earth Science Review (2004 -2009)
  • 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)
  • Chair of Gordon Research Conference on Flow and Transport in Permeable Media (2012)
  • National Academy of Science Board on Nuclear Radiation Studies Board (2014-2020)
  • Nuclear Waste Technical Review Board (NWTRB) (2017-date)


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


  1. Multiphase flow and remediation
    • Illangasekare, T.H., J. L. Ramsey, K.H. Jensen and M. Butts, 1995. Experimental study of movement and distribution of dense organic contaminants in heterogeneous aquifers, of Contaminant Hydrology, 20, 1-25.
    • Soga, K., Page, J.W.E. and Illangasekare, T.H. (2004) A review of NAPL source zone remediation efficiency and the mass flux approach. Journal of Hazardous Materials 110(1-3), 13-27.
  2. Groundwater flow, dissolution and reaction kinetics
    • Phenrat, T., Kim, H.J., Fagerlund, F., Illangasekare, T., Tilton, R.D. and Lowry, G.V. (2009) Particle Size Distribution, Concentration, and Magnetic Attraction Affect Transport of Polymer-Modified Fe-0 Nanoparticles in Sand Columns. Science & Tech. 43(13), 5079-5085.
    • Pieper, A.P., Ryan, J.N., Harvey, R.W., Amy, G.L., Illangasekare, T.H. and Metge, D.W. ,1997. Transport and recovery of bacteriophage PRD1 in a sand and gravel aquifer: Effect of sewage-derived organic matter. Science & Techn. 31(4), 1163-1170.
    • Saba, T. and Illangasekare, T.H. (2000) Effect of groundwater flow dimensionality on mass transfer from entrapped nonaqueous phase liquid contaminants. Water Resources Research 36(4), 971-979.
    • Saenton, S. and Illangasekare, T.H. (2007) Upscaling of mass transfer rate coefficient for the numerical simulation of dense nonaqueous phase liquid dissolution in heterogeneous aquifers. Water Resources Resh.43
  3. CO2 storage permanence
    • Agartan, E., Trevisan, L., Cihan, A., Birkholzer, J., Zhou, Q.L. and Illangasekare, T.H., 2015. Experimental study on effects of geologic heterogeneity in enhancing dissolution trapping of supercritical CO2. Water Reso. Resh. 51(3), 1635-1648.
    • Trevisan, L., Pini, R., Cihan, A., Birkholzer, J.T., Zhou, Q.L. and Illangasekare, T.H. ,2015. Experimental analysis of spatial correlation effects on capillary trapping of supercritical CO2 at the intermediate laboratory scale in heterogeneous porous media. Water Reso. Resh.51(11), 8791-8805
  4. Multiphase air and water flow and thermodynamic processes in subfreezing snow
    • Pfeffer, W.T., Illangasekare, T.H. and Meier, M.F. (1990) analysis and modelling of melt-water refreezing in dry snow. Journal of Glaciology 36(123), 238-246.
    • Pfeffer, W.T., Meier, M.F. and Illangasekare, T.H. (1991) Retention of Greenland runoff by refreezing – implications for projected future sea-level change. of Geophysical Research-Oceans 96(C12), 22117-22124.
  5. Virtual Sensor Networks in plume monitoring
    • 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
    • Jayasumana, Q. Han and T. Illangasekare, Virtual Sensor Networks – A Resource Efficient Approach for Concurrent Applications, Proc. 4th International Conference on Information Technology: New Generations (ITNG 2007), Las Vegas, NV, April 2007. (ITNG’07), Las Vegas, NV, 2007, pp. 111-115.
  6. Heat and mass flux across porous-media/free-flow interfaces
    • Trautz, A.C., Illangasekare, T.H. and Howington, S. (2018) Experimental Testing Scale Considerations for the Investigation of Bare-Soil Evaporation Dynamics in the Presence of Sustained Above-Ground Airflow. Water Resou. Resh. 54(11), 8963-8982.
    • Trautz, A.C., Illangasekare, T.H. and Rodriguez-Iturbe, (2017) Role of co-occurring competition and facilitation in plant spacing hydrodynamics in water-limited environments. Proceedings of the National Academy of Sciences (PNAS) 114(35), 9379-9384.
  7. Humanitarian science and engineering
    • Illangasekare, T., Tyler, S.W., Clement, T.P., Villholth, K.G., Perera, A., Obeysekera, J., Gunatilaka, A., Panabokke, C.R., Hyndman, D.W., Cunningham, K.J., Kaluarachchi, J.J., Yeh, W.W.G., van Genuchten, M.T. and Jensen, K.,2006. Impacts of the 2004 tsunami on groundwater resources in Sri Lanka. Water Res. Res. 42(5).
    • Illangasekare, T., Flow and Transport Modeling-Based Framework for Analysis of Potential Toxin Pathways Surface and Groundwater Systems to Address Some Aspects of Chronic Kidney Disease with Unknown Etiology (CKDu) in Sri Lanka, AGU Invited Session on Frontiers in Hydrology, AGU Fall Meeting,
    • Vithanage, M., Engesgaard, P., Jensen, K.H., Illangasekare, T.H. and Obeysekera, J.,2012. Laboratory investigations of the effects of geologic heterogeneity on groundwater salinization and flush-out times from a tsunami-like event. of Cont. Hydrology 136, 10-24.

Awards and Honors

  • Langbein Lecture Award (Bowie lecture) by the American Geophysical Union’s Bowie Lectures (2015)
  • Boland Hydrology Award, AGU, Hydrology Days, Colorado State University, 2011
  • Henry Darcy Medalist by the European Geoscience Union (EGU) (2012)
  • Honorary Doctorate for Science and Technology, Uppsala University, Sweden (2010)
  • Fellow of American Geophysical Union (2005)
  • Fellow of American Association for Advancement of Science (2007)
  • Fellow of American Society of Civil Engineers
  • Fellow of the Soil Science Society of America
  • Fellow of National Academy of Science of Sri Lanka (2017)
  • Colorado School of Mines Senate Excellence in Research Award (2010)
  • 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)