Theo Olsthoorn

Theo Olsthoorn joined the Water Resources Section as a part-time professor of groundwater exploration in September 2004. He is also senior researcher hydrology for Waternet (Amsterdam Water Supply). Professor Olsthoorn is a former MSc and PhD graduate of Delft University of Technology and has working experience in a number of renowned Dutch hydrological institutes.

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PhD, Technical University Delft, Faculty of Civil Engineering


MsC. Technical University Delft, civil engineering, (with honours). Specializing directions: drinking water & geohydrology. 


Work Experience


Senior Researcher Hydrology / Waternet


Part time professor TU-Delft / Geohydrology


Team leader hydrology & ecology, Amsterdam Water Supply


Head of hydrology, Amsterdam Water Supply, responsible for all hydrological research and advising within the company.


Senior researcher integrated environmental modeling. Head of centre for integrated environmental modeling.


Senior researcher/hydrologist RIVM (Governmental Institute of Public Health & Environmental Hygiene). Responsible for hydrological projects among others transboundary effects of German Lignite Mining and environmental effects of use of earth heat.


Kiwa (Dutch Water Companies Testing and Research Institute), project leader for advising projects on artificial recharge and groundwater issues.


IWACO water supply consultants. Project leader for projects in the field of geo-hydrology.


Project leader for the research on artificial recharge of groundwater by wells.


Professional activities


  • Part-time professor Geohyrolgy Delft. Courses Geohydrology I and II (CT4420, CT5440)
  • Invited lecturer at IHE (Advanced groundwater flow), 2001-present
  • Invited lecturer in the graduate course of Prof. Kop (Technical University Delft, Civil Engineering/Sanitary Engineering) on groundwater modeling using spreadsheets (about 1993-1997).
  • Post Academic Courses in Delft on artificial recharge of groundwater, and modeling of groundwater (several times).

Student supervision

  • MSc responsible for 10 students.
  • 7 promovendi (cadidates)
  • About 60 students carried out a traineeship for preparing their BSc or MSc on hydrology or water management within and for Amsterdam Water Supply since 1990.

Leadership & Coordination

  • IAHS, since ca. 1984, member of the board of the Dutch chapter since 2001, since 2010 president.
  • President of SWIM17, the 17th Salt Water Intrusion Meeting, Delft, 6-10 May 2002
  • Co-president of the one-day symposium “Calibration of Groundwater models”(In Dutch), Dutch Hydrological Association, 7 March 2001, Preface..
  • President of TISAR, the third international symposium on artificial recharge, Amsterdam 1998. The conference was opened by the crown Prince, Willem Alexander.
  • Co-president of the one-day symposium on calibration of groundwater models, 1996

Membership and Affiliation

  • IAHS, since ca. 1984, member of the board of the Dutch chapter since 2001, since 2010 president.
  • Royal Dutch Association of Water People (KVWN) since 1974
  • Werkgroep duurzaam gebruik ondergrond, Technische Commissie Bodembeheer (>2008)
  • Taskgroup Zandmotor Solleveld

List of professional publications


Olsthoorn, T.N. (1998) Groundwater modelling: calibration and the use of spreadsheets. Delft University Press, ISBN 90-407-1702-8 / CIP, about 300pp


Huisman, L. & T.N.Olsthoorn (1983) Artificial Groundwater Recharge. Pitman, advanced Publishing Program, Boston etc. 320pp.

Olsthoorn T.N. (1982) The Clogging of Recharge Wells (In Dutch). Kiwa research communication 71, Rijswijk, Netherlands ca. 450pp

Olsthoorn T.N. (1982) The Clogging of Recharge Wells, Main Subjects (In English). Kiwa research communication 72, Rijswijk, The Netherlands 136pp.

Refereed journal articles

Olsthoorn, T.N. (2009) Digitale geohydrologische informatie via DinoLoket Bruikbaar of liever terug naar de oude grondwaterkaarten? Stromingen, Vol 5, Nr. 1,75-76. + Ractie: Stromingen Vol15, Nr. 53-54

Mazijk, A., Olsthoorn, T.N. & Duijvenbode, S.W. van (2009) Het Betuwepand en het stoftransport in Lek en Amsterdam-Rijnkanaal bij lage Rijnafvoeren. Stromingen V15. Nr 3, 19-28

Olsthoorn, (2008) Do a bit more with convolution. Ground Water. V46, No. 3. 13-22 Olsthoorn, (2008) Wichelen (of: wat resteert na double-blind research?) Stromingen, Vol. 14 Nr. 3. 7-15.

Olsthoorn, T.N. (2007) Do a bit more with Convolution. Ground Water, Acc. April 2007, Doi: 10.1111/j: 1745-6584.2007.00342.x, 10pp

Olsthoorn, T.N. & P.T.W.J. Kamps (2006) Challenges to Calibration: Facing an Increasingly Critical Environment. Ground Water, Vol. 44, No. 6, 876, 879.

Bakker. M., E.I. Anderson, T.N. Olsthoorn & O.D.L. Strack (1999) Regional Groundwater Modeling of the Yucca Mountain site, using analytic elements. Journal of Hydrology, 226, 167-178

Olsthoorn, T.N. (1999) A comparative review of analytic and finite difference models used at Amsterdam Water Supply. Journal of Hydrology, 226, 139-143

Breukelen, B.M. van , C.A.J. Appelo & T.N. Olsthoorn (1998) Hydrochemical transport modeling of 24 years of Rhine Water Infiltration in the dunes of the Amsterdam Water Supply. Journal of Hydrology, 209 (1-4) 281-296.

Olsthoorn, T.N. (1995) Effective Parameter Optimization for Groundwater Model Calibration. Ground Water, Vol, 33, No. 1, Jan-Feb 1995, 42-48.

Frissel, M.J. & T.N.Olsthoorn (1989) Models by decision makers and ecologists, can they be coupled? In: M. Clarholm & L. Bergström (Eds.) Ecology of arable land, 273-279, Kluwer academic press.

Olsthoorn, T.N. (1985) The power of the electronic spreadsheet: Modeling without special programs. Ground Water, Vol. 23, No. 3, May-June 1985. 381-390.

Olsthoorn, T.N. (1982) Research with experimental recharge wells in Holland. DVWK Bulletin 14, Artificial Groundwater Recharge Vol. IV,  VI-11, p 191-223, Proceedings of the Intl. Symp. Artificial Recharge Research Results and Practical Applications, Dortmund, 14-18 May, 1979, Verlag Paul Parey, Hamburg/Berlin. ISBN 3-490-00690-9.

Refereed conference proceedings

Van Ginkel, Olsthoorn, Smidt en Darwich (Oct. 2010) Freshwater storage in saline aquifers, the FSSE well. Int. Symposium on Managed Aquifer Recharge, Abu Dhaby (2010)

Alam, N. & T.N.Olsthoorn (2010) Modeling for sustainable use of groundwater in Chaj Doab, Indus Basin, Pakistan.. 2010, April 11-15, Denver Groundwater Summit.

Olsthoorn, T.N. (2010) Improved Groundwater Modeling using an open and free environment, called mfLab. 2010, April 11-15, Denver Groundwater Summit.

Olsthoorn, T.N. (2010) Upconing-related dowstream long-term salinization and head phenomena in the Amsterdam Water Supply Dunes. 2010, June, 21-16. 21st Saltwater Intrusion Meeting (SWIM21) Ponta Delgada, Azores, Portugal.

Nienhuis, P., Kamps, P., Spillekom, S. & Olsthoorn, T.N. (2010) Comparing methods for exploring the fresh/salt groundwater interface position in the Amsterdam Water Supply Dunes. 2010, June, 21-16. 21st Saltwater Intrusion Meeting (SWIM21) Ponta Delgada, Azores, Purtugal.

Olsthoorn, T.N. (2009) Times Series Analysis is Essential to Ground Water Modeling . 2009, April 19-23, Tucson, AZ. Groundwater Summit

Alam, N. & T.N. Olsthoorn (2008) Institutional Innovations for Poverty Eradication: Optimization in Water Resources Projects and Agricultural Policies in the Indus Basin ,Pakistan. 2008, May, 19-21, Golden, Co. USA, Modflow & More

Olsthoorn, T.N. (2008) De wichelroede na de Scheunentests en Enright. 2008, May 22. NHV-symposium De Bron van Leven. Bunnik. Voordracht gehouden via Skype vanuit Golden USA.

Nathalie Emanuels, Goldmining Pollution Abatement Officer, WWF Guianas, Suriname Theo Olsthoorn, Hoogleraar grondwater, TU Delft en Hydroloog, Wereldwaternet, Nederland. 2008, May, 29-30. Paramaribo, Suriname. Conferentie: Duurzamen ontwikkeling Suriname: Workshop Water.

Olsthoorn, T.N. (2008) Brackish Groundwater as a new Resource for Drinking Water, Specific Consequences of Density Dependent Flow, and Positive Environmental Consequences. 174-177. 2008, Jun 23-27. Naples, FL, USA. Satwater Intrusion Meeting.

Schaars, F.W., T.N. Olsthoorn & M. Bakker (2008) The delayed effects of Variable Density Flow on Flow and Heads in Fresh Groundwater. 240-243. 2008, Jun 23-27. Naples, FL, USA. Satwater Intrusion Meeting.

Olsthoorn, T.N. & Li Ping (2007) 50 years experience with horizontal galleries of the Artificial Recharge System in the Amsterdam Dune Area. 2007, Oct 28- 31. Phoenix, AZ, International Sympositum on Managed Artificial Recharge (ISMAR4) .

Olsthoorn (2006) Interpreting a multiple well pumping test with 6000 cycles to determine safe yield. Manhattan, 5th Intl. Conf. on the Analytic Element Methods. Kansas Univ. Manhattan, Kansas, May 2006

Duijvenbode, S.W. van & T.N.Olsthoorn (2003) A pilot study of deep-well recharge by Amsterdam Water Supply. In: Dillon, P.J. (Ed) Management of Aquifer Recharge for Sustainability, Proceedings of the 4th intl. Symp. on Artificial Recharge of Groundwater, ISAR-4, Adelaide, South Australia, 22-26 Sep. 2002, A.A.Balkema publishers, ISBN 90-5809 527 4, p 447-451.

Olsthoorn, T.N. & M.M.Mosch (2002) Fifty years of artificial recharge in de Amsterdam Dune Area. In: Dillon, P.J. (Ed) Management of Aquifer Recharge for Sustainability, Proceedings of the 4th intl. symp. on artificial recharge of groundwater, ISAR-4, Adelaide, South Australia, 22-26 Sep. 2002, A.A.Balkema publishers, ISBN 90-5809 527 4, p 29-34

Olsthoorn, T.N. (2002)   In. Peters (Ed) Artificial Recharge of Groundwater, Proc. Of the Third Intl. Symp. On Artificial Recharge of Groundwater – TISAR 98, Amsterdam, 21-25 Sept. 1998, A.A.Balkema /Rotterdam/Brookfield/1998. ISBN 90 5809 017 5

Attia, F., M. Moustafa, T.Olsthoorn & E.Smit (1998) The role of artificial recharge in integrated water management in Egypt. Proc. Of the Third Intl. Symp. On Artificial Recharge of Groundwater – TISAR 98, Amsterdam, 21-25 Sept. 1998, A.A.Balkema /Rotterdam/Brookfield/1998. ISBN 90 5809 017 5, p 47-54

Duijvenbode, S.W. van & T.N.Olsthoorn (1998) Effects of natural channel bed filtration prior to deep-well injection. Proc. Of the Third Intl. Symp. On Artificial Recharge of Groundwater – TISAR 98, Amsterdam, 21-25 Sept. 1998, A.A.Balkema /Rotterdam/Brookfield/1998. ISBN 90 5809 017 5, P 67-72.

Olsthoorn, T.N. & F.W.Schaars (1998) Variable density groundwater modeling with MODFLOW: Example Amsterdam Dune Water Area. In: Poeter e.a. (Eds) Proceedings of  MODFLOW '98 Golden Colorado, Oct. 4-8, 1998,  vol 2, 579-586.

Olsthoorn, T.N. & P.T.W.J.Kamps (1996) Groundwater model calibration for the Amsterdam Water Supply Dune Area. Proceedings of the ModelCare 96 conferen, Golden, Co, Sept. 1996, IAHS publication No. 237, ISBN 0-947571-94-9. p 105-114

Kamps, P.T.W.J. & T.N.Olsthoorn (1996) Using GIS for hierarchical refinements of MODFLOW models. In: HydroGIS 96, Appl. of GIS in: Hydrogeology and Water Resources Management, Proceedings of the Vienna Conf. April 96, IAHS publ. 235, 535-542.

Olsthoorn, T.N. (1995) Artificial recharge by well at the Amsterdam Water Supply. In: Johnson, A.I. & D.G.Pyne (Eds) Artificial Recharge of Ground Water II. Proceedings of the 2nd intl. symposium on Artificial Recharge of Groundwater, Orlando, ASCE, 345 East 47th Street, New York, NY 10017-2398. ISBN 0-7844-0091-1, p 700-709.

Olsthoorn, T.N., P.T.W.J.Kamps & W.J.Droesen (1993) Groundwater modeling using GIS at the Amsterdam Water Supply. Hydrogis93, proceedings of the Vienna Conference, April 1993, IAHS Publ. 211, 665-674.

Droesen, W.J. & T.N. Olsthoorn (1991) Incorporating system knowledge in kriging of piezometric head. In: Harts e.a. (Eds)Proceedings of  2nd European Conf. on Geographical Information Systems, EGIS 91 Brussels, April 2-5 1991, Vol 1, 277-285.

Olsthoorn, T.N., Jaarsveld, J.A., Knoop, J.M., Egmond, N.D. van, Mülschlegel, J.H.C. & W. van Duijvenbooden (1989) Integrated modeling in the Netherlands. In: Fenhann, J.E.A> (Ed) Environmental models: Emissions and consequences. Risø (Denmark) Intl. Conf. 22-25 May, 1989, 461-479.

Invited Lectures

Olsthoorn T.N. (dec 2010) Dec AGU, San Francisco, 2010 – invitated to give a presentation on saltwater intrusion. Olsthoorn, T.N. (2008) Calibration of slow models. Featured presentation. 2008, May, 19-21, Golden, Co. USA, Modflow & More

Olsthoorn, T.N. (2006) Do a bit more with convolution. Modflow and More Conference, May 21-24 2006.

Olsthoorn, T.N. (2005) Systeem in het Grondwater. Vakantiecursus Drinkwatervoorziening en Afvalwaterbehandeling (Jan 2005, Delft).

Olsthoorn, T.N. (2003) We have to calibrate our renewed and extended model of the Amsterdam Dune Area reproducibly, scientifically on many different situations simultaneously. Featured talk, Modflow & More Conference, Golden, Colorado, Sept 16-19, 2003.

Olsthoorn, T.N. (2001) The Amsterdam dune area, the history of salt water intrusion and restoration.  1st Int Workshop on investigation, management and remediation of contaminated aquifers, Alicante Oct 18-19, 2001. The presentation was given on Oct 18 in Alicante and on Oct. 22 at the Geological Survey in Madrid.

Olsthoorn, T.N. (2001) The Amsterdam dune area, the history of salt water intrusion and restoration.  Facilitated Meeting on Saltwater Intrusion in Georgia. Savannah, September 17-18 (Published by Camp Dresser & MkCee  consultants (CDM)).

Olsthoorn, T.N. (2001) Modelling Odysseys, Featured talk, Modflow Conference, Golden, Colorado, Sept. 11-13, 2001.

Olsthoorn, T.N. (2001)  REGIS (Regional GIS) at the Amsterdam Water Supply (In Dutch). Symposium on Regional GIS, NITG-TNO/Province of South-Holland, 28 Sept. 2001.

Other papers and presentations

Olsthoorn, T.N. (2006) (Be)wegen van groundwater. Intreerede, TUDelft, 22/9/2006. Uitgegeven door TUDelft. 20p.

Olsthoorn T.N. (2006) Wat deden de Hilversummers met hun water? Rede bij de onthulling van het Aardkundig Monument, Hilversum, Okt. 2006.

Schulze, F., Olsthoorn, T., van Duijvenbode S. (2006) Optimalisatie operationeel peilbeheer Loosdrechtse Plassen met kunstmatige neurale netwerken. H2O, Vol. 39, Nr. 7 p 25-29

Bakker Olsthoorn (2006) 19th Salt Water Intrusion Meeting 25-29 Sept 2006, Cagliari. Stromingen, 12, No. 4, 44-47

Stuyfzand, P. Kortleve, M. Olsthoorn, T. Rolf, H. (2005) De duurzaamheid van kunstmatige infiltratie, geochemisch gesproken. H2O, Vol 38, No 17, 31-34

Olsthoorn, T. Vreemde verschijnselen verklaard. (Lisseeffect en water op ijs voorafgaand aan op til zijnde dooi) Stromingen 10, No. 1, p39

Olsthoorn, T. De eeuwige lopende band en de stijghoogte (Stromingen 10, Nr. 4, p37-38) Olsthoorn, T. en Smits, F. (2005) Hydrologische avonturen in Tsechië. Stromingen, 11, No. 1, 54-61

Olsthoorn, T.N. Van Edelman naar Bruggeman Stromingen 12, Nr 1, 5-12.

Tuinhof, Albert, Theo Olsthoorn, Jan Piet Heederik & Jacobus de Vries (2003) Management of Aquifer Recharge and Subsurface Storage: A promising option to cope with increasing storage needs. Proceedings of the Wageningen Conference, 19 December 2003, to be published.

Olsthoorn, Theo, Eileen Poeter & Jos Moorman (2002) Lessons from analyzing trial and error calibrated models for prediction reliability. Proceedings of ModelCare 2002, Edited By Kovar, IAHS Publication.

Olsthoorn, T.N. (2000) Wetting of the dunes cause of miljoens of dollars of damage to flower bulbs? (In Dutch: Vernatting in het duin oorzaak van miljoenenschade aan bloembollen, H2O), 2000, 25/26, 23-24.

Olsthoorn, T.N. (2000) Brackish-Saline water movement in the southern part of the Amsterdam Dune Water Area, 1925-2025. Proceedings of the Salt Water Intrusion Meeting, SWIM16, Miedzyzdroje, Wolin Island, Nicholas Copernicus University, Vol. 80, p119-126.

Olsthoorn, T.N. (2000) Steady-state one-dimensional multi-aquifer model using matrix functions with applications. 3rd Int. Conf. on the Analytic element method in modeling groundwater flow, Brainerd, MN, USA, 16-19 April, 2000.

Olsthoorn, T.N. (2000) A clay layer with holes? After the wet-damage in 47 flower bulb parcels in the Dune- and Flower-bulb area in 1997. (In Dutch). Stromingen, 6(2000)4, 5-12.

Olsthoorn, T.N. (2000) No wetting by freshening (In Dutch). Stromingen 6(2000)1

Olsthoorn, T.N. (2000) Complex number solutions of the book of Bruggeman. (In Dutch) Stromingen 6(2000)3, 5-7.

Olsthoorn, T.N. (2000) One-dimensional flow in multi-layer systems. (In Dutch). Stromingen 6(2000)2, 13-23.

Olsthoorn T.N., & F. van Pruissen (2001) The effect of rand removal from a lake on the groundwater seepage in its surroundings. (In Dutch) Stromingen, 5(1999)4, 45-48.

Olsthoorn T.N. (1999) Opinion: a groundwater hydrologist must know how to compute! (In Dutch) Stromingen 5(1999)2, 55-56.

Olsthoorn, T.N. (1998) Why are transmissivities around pumping stations always greater? A closer analysis. (In Dutch). Stromingen, 4(1998)4, 21-26.

Maas, C. & T.N.Olsthoorn (1997) Golden oldies go Matlab (In Dutch) Stromingen, 3(1997)4, 21-42.

Olsthoorn, T.N. (1997) When did we use finite elements, finite differences or analytic elements at the Amsterdam Water Supply? Companion of the Nunspeet Conference on Analytic-Based moeling of Groundwater Flow, Nunspeet, 10-17 April, 17-24.

Kamps, P.T.W.J. & T.N. Olsthoorn (1996) Optimization of a steady-stage model using MODINV. (In Dutch) In: “Modelkalibratie” Netherlands’ Hydological Association (NHV) Special Issue number 2, 75-88.

Olsthoorn, T.N. (1996) Variable density flow modeling with MODLFOW. In: Rapporter och meddelanden nr. 87. 14th Salt Water Intrusion Meeting, SWMI 1996, 16-21 June, Malmö, ISBN 91-7158-572-9, p 51-60.

Olsthoorn, T.N. (1996) Density computations using a standard groundwater model. (In Dutch). Stromingen Vol. 2, Nr. 2, 31-38.

Olsthoorn, T.N. (1996) The working group on model calibration (In Dutch) In: Modelkalibratie: Het automatisch ijken van grondwatermodellen. Netherlands’Hydrological Association, NHV-Special 2, 67-73.

Olsthoorn, T.N. (1996) Calibration Tools (In Dutch) In: Modelkalibratie: Het automatisch ijken van grondwatermodellen. Netherlands’Hydrological Association, NHV-Special 2, 67-73.

Peters, J.H., Olsthoorn, T.N. & R.A.Visser  (1995) Go go go when demand is low. Report of a study travel in Florida on artificial recharge of groundwater (In Dutch), H2O 28(1995)10, 296-298 & 301

Olsthoorn, T.N. (1995) Calibration of groundwater models using Monte Carlo and mathematical optimization (In Dutch) H2O, Vol. 28, Nr. 10, 310-315.

Olsthoorn, T.N. & S. van Harlingen (1994) Recharge wells, clean drilling by wall scraping (In Dutch) H2O, 27(1994)21, 636-638

Kamps, P.T.W.J., T.N.Olsthoorn  & W.J.Droesen (1993) Eco-hydrological research in the Luchter Dunes (In Dutch). In:: Use of GIS with groundwater modeling. One-day symposium 5 Okt. 1993, in Rapporten en Nota's No. 32 van CHO-TNO. 14pp.

Olsthoorn, T.N. (1992) Modeling of simultaneous flow of fresh and saline groundwater with a spreadsheet. In: Custodio,E & A.Galofré (Eds) Study and modeling of salt water intrusion into aquifers. Proceedings of the Saltwater Intrusion Meeting (SWIM), Barcelona, 1992. CIMME, Barcelona, 343-357.

Olsthoorn, T.N. (1990) Groundwater modeling using spreadsheets. Water storage under variable density in heterogeneous aquifers. (In Dutch) H2O, Vol. 23, No. 24, 664-669.

Olsthoorn, T.N. (1989) Modeling of simultaneous fresh-saline groundwater flow with a spreadsheet (In Dutch). H2O, Vol. 22, Nr. 22, 595-601.

Olsthoorn, T.N. (1988) Groundwater lowering by the German lignite mines in the Rur Valley Graben. Quantitative analysis of the differences between the German and the Dutch Model Study. (In Dutch) RIVM report, 728610001, 28pp, RIVM Bilthoven.

Olsthoorn, T.N. (1988) Modeling of surface water quality using a spreadsheet (In Dutch) H2O, Vol. 21, Nr. 18, 509-511.

Olsthoorn, T.N. (1987) Simulation of groundwater with spreadsheets. Some more examples. (In Dutch) H2O, Vol. 20, 129-130.

Olsthoorn, T.N. (1987) Groundwater modeling with spreadsheets, a more general approach. (In Dutch), H2O, Vol. 20, No. 18, 434-439.

Olsthoorn, T.N. & A.A.Kusse (1986) Approach and data processing for groundwater modeling applied in the study after the influence of German lignite mining (In Dutch) H2O, Vol. 19, Nr. 16, 367-372.

Olsthoorn, T.N. (1984) The power of the electronic spreadsheet: Modeling without special programs (In Dutch), H2O, Vol. 17, Nr. 3, 44ff

Olsthoorn, T.N. (1984) Impacts of large-scale seasonal storage of heat in Quarternary aquifers in the Netherlands (In Dutch). Tijdschrift Koninklijke Nederlandse Heide Maatschappij, themanummer: Warmteopslag in de bodem, water uit de duinen. February 1994, 61-63.

Olsthoorn, T.N. (1982) Practical calibration of groundwater models (In Dutch) Civiele & Bouwkundige Techniek, Vol. 1, Nr. 2, Feb. 1982, 27-34.

Olsthoorn, T.N. (1982) One-dimensional transient groundwater flow. Programmable calculators in the water industry (In Dutch) H2O, Vol. 15, Nr. 7, 145-149.

Olsthoorn, T.N. (1982) Anisotropy, a neglected Groundwater Flow Phenomenon (In Dutch), H2O, Vol. 15, Nr. 11, 261-267,273.

Olsthoorn, T.N. (1981) Hantush’s Well-Function in the Pocket Calculator (In Dutch), H2O, Vol. 14, Nr. 3, 397-398.

Olsthoorn, T.N. (1977) In Dutch Sand Formations Effective Porosity Equals Total Porosity with respect to advection in saturated groundwater flow (In Dutch), H2O, Vol. 10, Nr. 5, 118-120.

Olsthoorn T.N. (1974), H2O on Finite elements as an effective tool.

Theo Olsthoorn

Lecturer / Researcher