Department of Geoscience

Scientific papers and dissertations:

Vilhelmsen, T. N., Marker, P. A., Foged, N., Wernberg, T., Auken, E., Christiansen, A. V., Bauer-Gottwein, P., Christensen, S. & Høyer, A-S. (2019): A regional scale hydrostratigraphy generated from geophysical data of varying age, type and quality. Water Resources Management, 33(2), p. p. 539-553, https://doi.org/10.1007/s11269-018-2115-1.  

Frederiksen, R. R., Christensen, S., and Rasmussen, K. R. (2018): Estimating groundwater discharge to a lowland alluvial stream using methods at point-, reach-, and catchment-scale. Journal of Hydrology, 564, p. 836-845, doi.org/10.1016/j.jhydrol.2018.07.036.

Frederiksen, R. R., Christiansen, A. V., Christensen, S., and Rasmussen, K. R. (2017): A direct comparison of EMI data and borehole data on a 1000 ha data set. Geoderma, 303, p. 188–195, doi.org/10.1016/j.geoderma.2017.04.028.

Christensen, N. K., Ferre, T.P., Fiandaca, G., and Christensen, S. (2017): Voxel inversion of airborne electromagnetic data for improved groundwater model construction and prediction accuracy. . Hydrological Earth System Sciences Journal, 21, p. 1321–1337, doi:10.5194/hess-21-1321-2017.

Christensen, N. K., B. J. Minsley, and S. Christensen (2017): Generation of 3-D hydrostratigraphic zones from dense airborne electromagnetic data to assess groundwater model prediction error. Water Resour. Res., 53(2), p. 1019-1038, doi:10.1002/2016WR019141.

Christensen, S. (2017): Methods to correct and compute confidence and prediction intervals of models neglecting sub-parameterization heterogeneity – From the ideal toward practice. Advances in Water Resources, 100, p. 109-125, Doi: 10.1016/j.advwatres.2016.12.007.

Christensen, N.K., Christensen, S., Ferre, T. (2016): Testing alternative uses of electromagnetic data to reduce the prediction error of groundwater models. Hydrological Earth System Sciences Journal, 20(5), p. 1925-1946, DOI: 10.5194/hess-20-1925-2016.

Vilhelmsen, T.N., Christensen, S., Auken, E. (2016): On determining uncertainties of MRS estimated transmissivities for groundwater modelling. Geophysics, 81(4), p. WB63-WB73, DOI: 10.1190/geo2015-0494.1.

Refsgaard, J.C., Sonnenborg, T., Butts, M., Christensen, J., Christensen, S., Drews, M., Jensen, K., Jørgensen, F., Jørgensen, L., Larsen, M., Rasmussen, S., Seaby, L., Seifert, D., Vilhelmsen, T. (2016): Climate change impacts on groundwater hydrology – where are the main uncertainties and can they be reduced? Hydrological Sciences Journal, VOL. 61, NO. 13, 2312–2324, DOI: 10.1080/02626667.2015.1131899.

Jeppesen, J., Christensen, S. (2015): A MODFLOW Infiltration Device Package for simulating stormwater infiltration. Ground Water, 53(4), p. 542-549 (Published online 3 Sep. 2014), DOI: 10.1111/gwat.12255.

Vilhelmsen, T.N., Behroozmand, A.A., Christensen, S., Nielsen, T.H. (2014): Joint inversion of aquifer test, MRS, and TEM data. Water Resources Research, 50(5), p. 3956–3975, DOI: 10.1002/2013WR014679.

Watson, T., Doherty, J., Christensen, S. (2013): Parameter and Predictive Outcomes of Model Simplification. Water Resources Research, 49, p. 3952-3977, DOI: 10.1002/wrcr.20145.

Andersen, T.R., Poulsen, S., Christensen, S., Jørgensen, F. (2013): A synthetic study of geophysics-based modelling of groundwater flow in catchments with a buried valley. Hydrogeology Journal, 21(2), p. 491-503. DOI: 10.1007/s10040-012-0924-5.

Andersen, T.R., Huuse, M., Jørgensen, F., Christensen, S. (2012): Seismic investigations of buried tunnel valleys on- and offshore Denmark. In: Glaciogenic Reservoirs - Geological Society Special Publication, vol. 368; Eds: M. Huuse et al. The Geological Society of London. DOI: 10.1144/SP368.14.

Refsgaard, J.C., Christensen, S., Sonnenborg, T.O., Seifert, D., Højbjerg, A.L., Troldborg, L. (2012): Review of strategies for handling geological uncertainty in groundwater flow and transport modelling, Advances in Water Resources 36, p. 36-50, doi:10.1016/j.advwatres.2011.04.006.

Vilhemsen, T.N., Christensen, S., Mehl, S.W. (2012): Evaluation of MODFLOW-LGR in connection with a synthetic regional-scale model. Ground Water, 50(1), p. 118-132, doi: 10.1111/j.1745-6584.2011.00826.x.

²    Doherty, J., Christensen, S. (2011): Use of Paired Simple and Complex Models to Reduce Predictive Bias and Quantify Uncertainty, Water Resources Research, 47, W12534, doi:10.1029/2011WR010763.

Jeppesen, J., Christensen, S., Ladekarl, U.L. (2011): Modeling the historical water cycle of the Copenhagen Area 1850-2003. Journal of Hydrology, vol. 404, p. 117-129, DOI: 10.1016/j.jhydrol.2010.12.022.

Poulsen, S.E., Christensen, S., Rasmussen, K.R., Werner, A. (2011): Simulation of groundwater flow and salt transport in a shallow microtidal barrier aquifer during a storm surge. . In: Conceptual and Modelling Studies of Integrated Groundwater, Surface Water, and Ecological Systems. IAHS Publ. 345, p. 55-61.

Poulsen, S.E., Christensen, S., Rasmussen, K.R. (2011): The interaction between the unsaturated zone, aquifer, and stream during a period of groundwater withdrawal. Journal of Hydrology, vol. 396, p. 49-60, DOI 10.1016/j.jhydrol.2010.10.029.

Poulsen, S.E., Rasmussen, K.R., Christensen, N.B., & Christensen, S. (2010): Evaluating the Salinity Distribution of a Shallow Coastal Aquifer by Vertical Multi Electrode Profiling. Hydrogeology Journal, vol. 18 , no. 1, p. 161-171, DOI 10.1007/s10040-009-0503-6.

Christensen, S., Zlotnik, V.A., and Tartakovsky, D.M. (2010): On the use of analytical solutions to design pumping tests in leaky aquifers connected to a stream. Journal of Hydrology, vol. 381, p. 341-351, doi:10.1016/j.jhydrol.2009.12.007.

Christensen, S., Zlotnik, V.A., and Tartakovsky, D.M. (2009): Optimal design of pumping test to predict stream flow depletion caused by pumping from a leaky aquifer. Journal of Hydrology, vol. 375(3-4), p. 554-565, doi:10.1016/j.jhydrol.2009.07.006.

Jeppesen, J., and Christensen, S. (2009): Modelling of the urban water cycle and the consequences of massive rain runoff infiltration for Copenhagen. In: Improving Integrated Surface and Groundwater Resources Management in a Vulnerable and Changing World (Proc. of JS.3 at the Joint IAHS & IAH Convention, Hyderabad, India, September 2009). IAHS Publ. 330, 2009, p. 34-41.

Christensen, S., & J. Doherty (2008): Predictive error dependencies when using pilot points and singular value decomposition in groundwater model calibration. Advances in Water Resources, vol. 31, no. 4, p. 674-700, DOI: 10.1016/j.advwatres.2008.01.003.

Christensen, S., & J. Doherty (2008): Using many pilot points and singular value decomposition in groundwater model calibration. In: Calibration and Reliability in Groundwater Modelling: Credibility in modelling (ed. J.C. Refsgaard, K. Kovar, E. Haarder, and E. Nygaard). Proc. ModelCARE'2007 (Copenhagen, September 2007). IAHS Publ. no. 320, p. 235-239.

Christensen, S., C. Moore, & J. Doherty (2006): Comparison of stochastic and regression based methods for quantification of predictive uncertainty of model-simulated wellhead protection zones in heterogeneous aquifers. Calibration and Reliability in Groundwater Modelling: From Uncertainty to Decision Making (Edited by M.F.P. Bierkens, J.C. Gehrels, and K. Kovar), Proceedings of ModelCARE’2005, The Hague, The Netherlands, June 2005,. IAHS Publ. 304, p. 202-208.

Cooley, R.L. & S. Christensen (2006): Bias and Uncertainty in Regression-Calibrated Models of Groundwater Flow in Heterogeneous Media. Advances in Water Resources, vol. 29, no. 5, p. 639-656.

Langhoff, J.H., K.R. Rasmussen, & S. Christensen (2006): Quantification and regionalization of groundwater-surface water interaction along an alluvial stream. Journal of Hydrology, vol. 320, no. 3-4, p. 342-358.

Christensen, S. (2005): Comment on ”Sensitivity analysis and determination of streambed leakance and aquifer hydraulic properties” by X. Chen and X. Chen. Journal of Hydrology, vol. 303, no. 1-4, 316-321.

Ladekarl, U.L., K.R. Rasmussen, S. Christensen, K.H. Jensen, & B. Hansen (2005): Groundwater recharge and evapotranspiration for two natural ecosystems covered with oak and heather. Journal of Hydrology, vol. 300, no. 1-4, 76-99.

¹    Christensen, S. (2004): A synthetic groundwater modelling study of the accuracy of GLUE uncertainty intervals. Nordic Hydrology, vol. 35, no. 1, pp. 45-59.

Nyholm, T., K.R. Rasmussen & S. Christensen (2003): Estimation of stream flow depletion and uncertainty from discharge measurements in a small alluvial stream. Journal of Hydrology, vol. 274, no. 1-4, p. 129 - 144.

Dam, D. & S. Christensen (2003): Including geophysical data in groundwater model inverse calibration. Ground Water, vol. 41, no. 2, p. 178-189.

Christensen, S., and Cooley, R.L. (2003) Experiences gained in testing a theory for modelling groundwater flow in heterogeneous media. In: Calibration and Reliability in Groundwater Modelling: A Few Steps Closer to Reality (ed. by K. Kovar & Z. Hrkal). Proc. ModelCARE'2002 (Prague, June 2002). IAHS Publ. no. 277, p. 22-27.

Nyholm, T., S. Christensen & K.R. Rasmussen (2002): Flow depletion in a small stream caused by ground water abstraction from wells. Ground Water, vol. 40, no. 4, p. 425-437.

Langhoff, J., S. Christensen. & K.R. Rasmussen (2001). Scale dependent hydraulic variability of a stream bed on an outwash plain. In: Impact of Human Activity on Groundwater Dynamics, edited by H. Gehrels, N.E. Peters, E. Hoelm, K. Jensen, C. Leibundgut, J. Griffioen, B. Webb, and W.J. Zaadnoordijk. IAHS Publ. no. 269: 205-212.

Christensen, S. (2000): On the estimation of stream flow depletion parameters by drawdown analysis Ground Water, vol. 38, no. 5, p.726-734.

Christensen, S. & R.L. Cooley (1999): Evaluation of prediction intervals for expressing uncertainties in groundwater flow model predictions. Water Resources Research, vol. 35, no. 9, p. 2627-2639.

Christensen, S. & R.L. Cooley (1999): Evaluation of confidence intervals for a steady-state leaky aquifer model. Advances in Water Resources, vol. 22, no. 8, p. 807-817.

Elberling, B., F. Larsen, S. Christensen & D. Postma (1998): Gas transport in a confined unsaturated zone during atmospheric high pressure cycles. Water Resources Research, vol. 34, no. 11, p. 2855-2862.

Christensen, S., K.R. Rasmussen & K. Møller (1998): Prediction of regional ground-water flow to streams. Ground Water, vol. 36, no. 2, p. 351-360.

Christensen, S. (1997): On the strategy of estimating regional-scale transmissivity fields. Ground Water, vol.35, no. 1, p. 131-139.

Christensen, S. & R.L. Cooley (1996): Simultaneous confidence intervals for a steady-state leaky aquifer groundwater flow model. In Calibration and Reliability in Groundwater Modelling, ed. by K. Kovar & P. van der Heide, IAHS publ. no. 237, p. 561-569.

Christensen, S. (1995): Prediction of Log-Transmissivity - 1. Using Specific Capacity. Nordic Hydrology, vol. 26, no. 1, p. 1-20.

Christensen, S. (1995): Prediction of Log-Transmissivity - 2. Using Lithology and Specific Capacity. Nordic Hydrology, vol. 26, no. 1, p. 21-36.

Christensen, S. (1994): Hydraulic conductivity and transmissivity estimation for groundwater models at various scales. PhD Thesis, English summary. Dept. of Earth Sciences, Aarhus University, 21 p.

Christensen, S. (1994): Hydrological model for the Tude å catch­ment. Nordic Hydrology, vol. 25, no. 3, p.145-166.

Refsgaard, A., S. Christensen & J. Reffstrup (1988): Finite Element Analysis of Controlled Saltwater Intrusion in Heterogeneous Reservoirs. Nordic Hydrology, vol. 20, no. 1, pp. 25-42.

 

¹   Winner of the prize for the best article in Nordic Hydrology in 2004-2005, awarded by the Nordic Hydrological Association at the XXIV Nordic Hydrological Conference.

²   AGU “Research Spotlight” paper.

 

Scientific reports:

Iversen, C.H., Troldborg, L., Møller, R.R., and Christensen, S. (2010): Dynamiske og stationære oplandsberegninger udført med tre semi-syntetiske modeller – Delprojekt 2 om oplande. Rapport udarbejdet af GEUS for By- og Landskabsstyrelsen, Miljøministeriet. GEUS, 88 pp.

Poulsen, S.E., and Christensen, S. (2010): Høfde 42: Hydrauliske beregninger vedrørende oprensning af et forsøgsvolumen. Geologisk Institut, Aarhus Universitet - Rapport udarbejdet for Region Midtjylland.

Poulsen, S.E., and Christensen, S. (2010): Høfde 42: Hydrauliske beregninger vedrørende risikovurdering. Geologisk Institut, Aarhus Universitet - Rapport udarbejdet for Region Midtjylland.

Poeter, E.P., Hill, M.C., Banta, E.R., Mehl, S., and Christensen, S. (2005): UCODE_2005 and Six Other Computer Codes for Universal Sensitivity Analysis, Calibration, and Uncertainty Evaluation: U.S. Geological Survey Techniques and Methods 6-A11, 283p.

Christensen, S. & R.L. Cooley (2004): User guide to the UNC1NLI1 package and three utility programs for computation of nonlinear confidence and prediction intervals using MODFLOW-2000. U.S. Geological Survey, Techniques and Methods Report 2004-1349, http://pubs.usgs.gov/tm/2006/tm6A10/

Dahl, M., J.H. Langhoff, B. Kronvang, B. Nilsson, S. Christensen, H.E. Andersen, C.C. Hoffmann, K. R. Rasmussen, F. von Platen-Hallermund, & J. C. Refsgaard (2004): Videreudvikling af ådalstypologi – Grundvand-Overfladevand Interaktion (GOI). Arbejdsrapport fra Miljøstyrelsen nr. 16, 2004.

Nilsson, B., J.C. Refsgaard, M. Dahl, I. Møller, B. Kronvang, H.E. Andersen, C.C. Hoffmann, S. Christensen, J.H. Langhoff, K.R. Rasmussen (2003): Grundvand - Overfladevand Interaktion (GOI). En metode til klassificering af ådale i typeområder. Arbejdsrapport fra Miljøstyrelsen nr. 10, 2003.

Christensen, S. (1995): On the strategy of estimating the transmissivity field of a regional-scale groundwater model. Internal research report, Dept. of Earth Sciences, Aarhus University, Aarhus, 37 pp.

Christensen, S. (1995): Calibration data accuracy in a regional-scale groundwater model. Internal research report, Dept. of Earth Sciences, Aarhus University, Aarhus, 29 pp.

Christensen, S. (1994): A case study of the estimation of the log-transmissivity semi-variogram by cross-validation error minimization. Internal research report, Dept. of Earth Sciences, Aarhus University, 36 p.

Christensen, S., J. H. Madsen & K. H. Jensen (1989): Oil Migration in Soil and Groundwater (Oliestrømning i jord og grundvand, in Danish). Arbejdsrapport no. 32, Danish Environmental Protection Agency, Copenhagen, 91 p.

Dakofa (Danish Committee for Waste) (1985): Groundwater Monitoring at Controlled Landfills (Grundvandskontrol ved kontrollerede affaldsdeponi­er, in Danish). Dakofa publ. no. 1, polyteknisk Forlag, Lyngby, 319 p.

Priisholm, S. & S. Christensen (1985): Assessment of Geothermal Resour­ces and Reserves in Denmark. A contribution to the geothermal resource and reserve estimate of the European Community. Geologi­cal Survey of Denmark, DGU series C no. 2, 73 p.

 

 

Conference papers, abstracts and posters:

Minsley, B.J., Christensen, N.K. Christensen, S., and Ley-Cooper, A. (2018). Model structural uncertainty quantification and hydrogeophysical data integration using airborne electromagnetic data. Extended abstract and poster for AEM2018, 7^th International Workshop on Airborne Electromagnetics, June 17-20, Hotel Kolding Fjord, Denmark.

Vilhelmsen, T.N., Christensen, S., Frederiksen, R.R., Auken, E., Christiansen, A.V. (2018): Gentænk grundvandsmodellering - nye metoder til effektiv modeludvikling. Vintermøde 2018, Vingstedcentret, March 6-7 2018. ATV-Jord og Grundvand, DTU, Lyngby, Denmark.

Vilhelmsen, T.N., Christiansen, A.V., Frederiksen, R.R., Christensen, S., Auken, E., (2018): Geofysisk kortlægning af terrænnære strukturer og deres betydning for grundvandet. Hydrologidag 2018, 23. Oct. 2018, Odense, Denmark.

Vilhelmsen, T.N., Christensen, S., Frederiksen, R.R., Auken, E., Fienen, M.N., Leaf, A. (2018): Script based groundwater modelling for increased model flexibility and improved analysis. 12^th Annual Water Research Meeting, 30. Jan. 2018. Lyngby, Denmark. Danish Water Forum

Minsley, B., Christensen, N.K., Christensen, S., Ley-Cooper, Y. (2017): Model structural uncertainty quantification and hydrologic parameter and prediction error analysis using airborne electromagnetic data. Abstract for the SAGEEP 2017 conference, March 19-23 2017, Denver, Colorado, USA.

Frederiksen, R.R., Rasmussen, K.R., Christensen, S. (2017): Quantifying and understanding runoff to an agricultural stream using geophysical, hydraulic and numerical methods. Contribution to 11th Annual DWF Meeting, Copenhagen 30 Jan. 2017.

Madsen, T.M., Christensen, S. (2016): From innovation to commercial market – understanding technological innovation systems. Abstract  for 2nd Young Water Professionals Denmark Conference and Workshop, Aarhus 10-11 March 2016.

Iversen, B.V., Kjærgaard, C., Petersen, R.J., Christensen, S., Rasmussen, K.R. (2016): Predicting tile drainage discharge. Conference abstract and poster for ASA, CSSA, SSSA 2016 Annual Meeting, Arizona, 6-9 November, 2016.

Andersen, T.R., Jørgensen, F., Christensen, S: (2016): Delineation of tunnel valleys across the North Sea coastline, Denmark based on reflection seismic data, boreholes, TEM and Schlumberger soundings. Paper presented at ASEG-PESA-AIG 2016, August 21–24, 2016, Adelaide, Australia, 10 p.: http://www.publish.csiro.au/?act=view_file&file_id=ASEG2016ab122.pdf.

Minsley, B.J., Christensen, N.K. Christensen, S., and Ley-Cooper, A. (2015). Model structural uncertainty quantification and hydrogeophysical data integration using airborne electromagnetic data (Invited), Oral and Abstract NS22A-03 presented at Fall Meeting, AGU, San Francisco, Calif., 14-18 Dec., https://agu.confex.com/agu/fm15/meetingapp.cgi/Paper/58917.

Frederiksen, R.R., Rasmussen, K.R., Christensen, S. (2015): Characterisation and quantification of groundwater-surface water interactions along an alluvial stream using geophysical, hydraulic and tracer methods. AGU Fall Meeting, Dec. 14-18, 2015, San Fransisco, United States. https://agu.confex.com/agu/fm15/meetingapp.cgi/Paper/80182.

Madsen, T.M., Christensen, S., Poulsen, S.E. & Sørensen, I. (2015). Analysis of effect of heat storage on efficiency of ground source heat pump system (In Danish: Analyse af varmelagringens betydning for effektiviteten af jordvarmeboringer). ATV-vintermøde, Denmark, 9. march 2015.

Madsen, T.M., Christensen, S., Poulsen, S.E. & Sørensen, I. (2015). Analysis of impact of heat extraction from soil with low thermal conductivity. 1st Workshop of Numerical Geothermal Simulation, Germany, 8.-9. April 2015.

Madsen, T.M., Christensen, S., Poulsen, S.E. & Sørensen, I. (2015). The effect of thermal depletion on the performance of a ground source heat pump system. 13th Internaltional UFZ-Deltares Conference on Sustainable Use and Mangement of Soil, Sediment and Water ressources (AquaConSoil), Denmark, 9.-12. June 2015.

Vilhelmsen, T. N., Christensen, S. & Auken, E. (2015). On determining uncertainties of MRS estimated transmissivities. Oral and Abstract presented at The 6th International Workshop on Magnetic Resonance, 8-10 June, Aarhus University, Aarhus, Denmark.

Minsley, B.J., S. Christensen, and N.K. Christensen (2014), A sequential hydrogeophysical approach to quantify model structural uncertainty, Poster and Abstract NS31B-3924 presented at Fall Meeting, AGU, San Francisco, Calif., 15-19 Dec. http://abstractsearch.agu.org/meetings/2014/FM/NS31B-3924.html

Christensen, N. K., Christensen, S., and Ferre, T (2014). Integrating geophysics and hydrology for reducing the uncertainty of groundwater model predictions and improved prediction performance, Poster and Abstract H51B-0602 presented at Fall Meeting, AGU, San Francisco, Calif., 15-19 Dec. http://abstractsearch.agu.org/meetings/2014/FM/H51B-0602.html

 Iversen, B. V., Petersen, R.J., Christensen, S., Rasmussen, K. R., Kjærgaard, C. (2014): Modelling Tile Drainage Discharge Using a Linear Reservoir Model. Poster presented at ASA, CSSA, & SSSA International Annual Meeting, Long Beach, California, United States, 3^rd Nov. 2014, https://scisoc.confex.com/scisoc/2014am/webprogram/Paper88804.html.

Iversen, B. V., Kjærgaard, C., Rasmussen, K. R., Christensen, S. (2014): Afvanding via dræn og betydning i forhold til målrettet regulering. In conference proceedings from Plantekongres 2014, Herning, Denmark, 14/01/14 - 14/01/14, ISBN 978-87-92869-86-9.

Frederiksen, R. R., Rasmussen, K. R. & Christensen, S. (2014): Rainfall-runoff mechanisms on a hill-island. Poster for TERENO International Conference 2014, September 29th - October 2nd 2014 Rheinische Friedrich-Wilhelms-Universität Bonn, Germany.

Minsley, B.J., Christensen, N.K., Christensen, S, (2014): Using airborne geophysical data to reduce groundwater model uncertainty. Abstract for SIAM Conference on Uncertainty Quantification, March 31 to April 3, 2014, Savannah, Georgia.

Christensen, N. K., Christensen, S., Ferre, T. (2014): Testing how geophysics can reduce the uncertainty of groundwater model predictions. Abstract from European Geosciences Union General Assembly 2014, Vienna, Austria.

Frederiksen, R.R., Rasmussen, K.R., Christensen, S. (2014): Surface water and groundwater interaction on a hill island. Poster at EGU General Assembly 2014, Vienna, Austria.

Christensen, N. K., Christensen, S., Ferre, T. (2014): Hydro-geophysical "Testbench" (In Danish: Hydro-geofysisk "Testbench"). Abstract from ATV Vintermøde om Forurenet Jord og Grundvand, Vingsted, Denmark.

Vilhelmsen, T.N., Behroozmand, A., Christensen, S., Nielsen, T.H. (2013). A framework for joint inversion of aquifer test, MRS and TEM data. Abstract from MODFLOW and More 2013, Golden, CO, USA.

Vilhelmsen, T.N., Christensen, S., Doherty, J. (2013). Testing the importance of numerical resolution for calibration and prediction when modeling aquifer systems located in buried valleys. Poster presented at MODFLOW and More 2013, Golden, CO, USA.

Vilhelmsen, T.N., Christensen, S., Behroozmand, A., Nielsen, T.H., Auken, E. (2012): An efficient full coupled inversion of aquifer test, MRS and TEM data. Magnetic Resonance in the Subsurface : 5th International Meeting on Magnetic Resonance, Sep. 25, 2012, Hannover, Germany.

Brunner, P., Doherty, J., Christensen, S., Simmons, C.T. (2011): To what extent does the degree of meaningful model complexity depend on observation data?   Geological Society of America Annual Meeting in Minneapolis, 8-12 October 2011, Paper No. 140-2.

Jeppesen, J., S. Christensen (2011): The hydrological preconditions for using LAR – groundwater as a limiting factor (In Danish: De hydrologiske forudsætninger for LAR – grundvand som en begrænsende faktor). In proceedings of the symposium “Vintermøde om jord og grundvandsforurening” at Vingstedcentret, March 8-9 2011. ATV-Jord og Grundvand, DTU, Lyngby, Denmark.

Andersen, T.R., F. Jørgensen, S. Christensen (2011): Comparison and correlation of buried tunnel valleys in Denmark and the North Sea (In Danish: Sammenstilling og korrelation af begravede tunneldale i Danmark og Nordsøen). In proceedings of the symposium “Vintermøde om jord og grundvandsforurening” at Vingstedcentret, March 8-9 2011. ATV-Jord og Grundvand, DTU, Lyngby, Denmark.

Vilhemsen, T.N., S. Christensen (2010): Test of two versions of MODFLOW-LGR for simulation of groundwater flow in areas with buried valleys – synthetic study. (In Danish: Test af to versioner af MODFLOW-LGR til simulering af grundvandsstrømning i områder med begravede dale – syntetisk studie.) In proceedings of the symposium “Vintermøde om jord- og grundvandsforurening” at Vingstedcentret, March 9-10 2010. ATV-Jord og Grundvand, DTU, Lyngby, Denmark. P. 199-210. Presented as a poster at the symposium.

Jeppesen, J., S. Christensen (2010): The hydrological possibilities and consequences of using sustainable urban drainage systems in Copenhagen. Abstract for 4th annual meeting of the Danish Water Research Platform, held at GEUS, Copenhagen, Danmark, 28. januar 2010 - 29. januar 2010.

Vilhelmsen, T.N., Christensen, S. (2009): Testing MODFLOW-LGR for simulating flow around Buried Quaternary valleys - synthetic test cases. Poster presented at 2009 AGU Fall Meeting, San Francisco, Calif., USA, 14.-18.  December 2009.

Andersen, T.R., Huuse, M., Jørgensen, F., Christensen, S. (2009): Seismic characterization of tunnel valleys. Abstract for The Geological Society conference ”Glaciogenic Reservoirs and Hydrocarbon Systems”, London, United Kingdom, 1. December 2009 - 2. December 2009.

Andersen, T.R., Jørgensen, F., Sandersen, P., Christensen, S. (2009): Mapping and modeling buried tunnel valleys. Poster presented at AGU 2009 Joint Assembly – The Meeting of the Americas, Toronto, Canada, 24. maj 2009 - 27. maj 2009.

Jeppesen, J., S. Christensen (2009): Urban versus climatic impacts on the water cycle of the Copenhagen area 1850-2003. Abstract for 3rd annual meeting of the Danish Water Research Platform, held at Geocenter Copenhagen, 29. January 2009, p. 15-16.

Jeppesen, J., Christensen, S. (2009): Use of an integrated model to simulate the urban water cycle and consequences of massive storm water infiltration. Poster presented at The 11th Nordic Wastewater Conference, Odense, Denmark, 10.-12. November 2009.

Andersen, T.R. Jørgensen, F., Christensen, S. (2008): A comparison of onshore and offshore buried tunnel valleys along the Danish North Sea coastline. Poster presented at The 33rd International Geological Congress, Oslo, Norge, 6.-14. August 2008.

Poulsen, S.E., S. Christensen, K.R. Rasmussen, J.S. Mortensen, A. Viezzoli (2008): An Investigation of Groundwater Flow on a Coastal Barrier using Multi Electrode Profiling. SWIM - 20th Salt Water Intrusion Meeting - Program and Proceedings, 20th Salt Water Intrusion Meeting, June 23-27, 2008, Naples, Florida, p. 209-212.

Jeppesen, J., S. Christensen, U.L. Ladekarl (2008): Conceptual model for simulating the water cycle of the Copenhagen area, Denmark. Paper for MODFLOW 2008 conference, May 19-21, Golden, Colorado.

Jeppesen, J., S. Christensen, and U.L. Ladekarl (2008): Simulation of the historical development of the water cycle of the Copenhagen area, Denmark. EGU General Assembly 2008, Vienna, Austria, Abstract number EGU2008-A-05371.

Christensen, S., & J. Doherty (2007): Using many pilot points and singular value decomposition in groundwater model calibration. Pre-published proceedings of ModelCARE’2007 , Sixth Int. Conf. on Calibration and Reliability in Groundwater Modelling – Credibility in Modelling, Copenhagen, Denmark, 9-13 September 2007, p. 448-453.

Jeppesen, J., & S. Christensen (2007): Use of a regional model to simulate the historical water cycle of the Copenhagen Area 1850-2003. Poster and Extended abstract in Pre-published proceedings of ModelCARE’2007 , Sixth Int. Conf. on Calibration and Reliability in Groundwater Modelling – Credibility in Modelling, Copenhagen, Denmark, 9-13 September 2007, p. 204-205.

Poulsen, S.E., S. Christensen & K.R. Rasmussen (2007):  An investigation of the interaction between the unsaturated zone, aquifer, and stream during a period of groundwater abstraction. Poster and Extended abstract in Pre-published proceedings of ModelCARE’2007 , Sixth Int. Conf. on Calibration and Reliability in Groundwater Modelling – Credibility in Modelling, Copenhagen, Denmark, 9-13 September 2007, p. 330-331.

Christensen, S., C. Moore, & J. Doherty (2005): Comparison of stochastic and regression based methods for quantification of predictive uncertainty of model-simulated wellhead protection zones in heterogeneous aquifers. Pre-published proceedings of ModelCARE 2005, Fifth Int. Conf. on Calibration and Reliability in Groundwater Modelling – From Uncertainty to Decision Making, The Hague (Scheveningen) The Netherlands, 6-9 June 2005, p. 440-447.

Christensen, S. (2005): Can the data basis and modelling used in the Danish mapping of groundwater vulnerability be improved? (Kan sårbarhedskortlægningens datagrundlag og brug af modeller forbedres? In Danish). ) In proceedings of the symposium "Hvordan bruger vi modeller?" at Schæffergården, Copenhagen, January 27th 2005. ATV-Jord og Grundvand, DTU, Lyngby, Denmark.

Nilsson, B., M. Dahl, J.H. Langhoff, B. Kronvang , S. Christensen, H.E. Andersen, C.C. Hoffmann, K.R. Rasmussen, & J.C. Refsgaard (2004): Groundwater/surface water interaction – a Danish typological approach. EGU 1^st Assembly, Nice, France, April 2004.

Langhoff, J.H., S. Christensen, K.R. Rasmussen (2003) Using orthophotos to map the groundwater / surface water interaction type on an outwash plain. EGS-AGU-EUG Joint Assembly, Nice, France, April 2003. Abstract number EAE03-A-06180.

Nilsson, B., S. Christensen, B. Kronvang, J.H. Langhoff, M. Dahl, C.C. Hoffmann, H.E. Andersen, K.R. Rasmussen, J.C. Refsgaard, (2003): Methodology to classify groundwater / surface water interaction. EGS-AGU-EUG Joint Assembly, Nice, France, April 2003. Abstract number EAE03-A-10772.

Nilsson, B., M. Dahl, B. Kronvang, and S. Christensen (2003): Methodology to characterize interaction between groundwater and surface water. (Typlogi til karakterisering af samspil mellem grundvand og vandløb, in Danish). In proceedings of the symposium "Samspil mellem grundvand og overfladevand " in Aarhus, November 6th 2003, arranged by  ATV Jord og Grundvand.

Nilsson, B., J. H. Langhoff, M. Dahl, B. Kronvang, S. Christensen, C.C. Hoffmann, H.E. Andersen, K.R. Rasmussen and J.C. Refsgaard (2003): Methodology to classify stream valleys after geological stream valley morphological principles (Metodik til karakterisering af ådale I typeområder efter geologiske og ådals-morfologiske principper, In Danish). In proceedings of the symposium "Vintermøde om Jord og Grundvandsforurening”, at Vingstedcentret, Vingsted, March 2003. ATV-Jord og Grundvand, DTU, Lyngby, Denmark.

Christensen, S. and R.L. Cooley (2002). Experiences from the testing of a theory for modelling groundwater flow in heterogeneous media. Ed. K. Kovar and Z. Hrkal, Proceedings of the 4^th Int. Conf. On Calibration and Reliability in Groundwater Modelling, ModelCARE=2002, Prague, Czech Republic, 17-20 June 2002. Charles University, Prague.

Christensen, S. (2002). A synthetic groundwater modelling study of the accuracy of GLUE uncertainty intervals.  Geophysical Research Abstracts, Vol. 4, 2002, 27th General Assembly of EGS in Nice. Abstract number EGS02-A-00940.

Langhoff, J.H., S.Christensen, and K.R. Rasmussen (2002). Groundwater seepage to a stream having low conductivity streambed and a wide, wet riparian zone. Geophysical Research Abstracts, Vol. 4, 2002, 27th General Assembly of EGS in Nice. Abstract number EGS02-A-06718.

Laderkarl, U.L., K.R. Rasmussen, and  S. Christensen (2002). SVAT-modelling of a forest water balance - estimation and validation. Geophysical Research Abstracts, Vol. 4, 2002, 27th General Assembly of EGS in Nice. Abstract number EGS02-A-03909.

Dam, D. and S. Christensen (2001). Method for estimating hydraulic parameters using geoelectrical data. MODFLOW 2001 and Other Modelling Odysses - Conference Proceedings (vol. 1), eds. Seo, Poeter, Zheng and Poeter. IGWMC, Colorado School of Mines, Colorado, Sept. 11-14, 2001. 137-143.

Dam D., S. Christensen and N. B. Christensen (2000): Characterizing the hydraulic conductivity field using electrical resistivity and inverse modelling. Proceedings of GroundWater 2000, International Conference on Groundwater Research, Rosbjerg et al. (eds), Balkema, Rotterdam, ISBN 90 5809 133 3, 9-10, June 2000.

Christensen, S., T. Nyholm, and K.R. Rasmussen (2000): On the parameter estimation and prediction of stream flow depletion caused by pumping from a well. Geophysical Research Abstracts, Vol. 2, 2000, 25th General Assembly of EGS in Nice.

Ladekarl, U.L., K.R. Rasmussen, P. Nørnberg, B. Hansen and S. Christensen (1999): Recharge under two different vegetation types on sandy soils. Abstract for 24th General Assembly of EGS in Holland. Geophysical Research Abstracts, Vol. 1, Number 2, p 330.

Christensen, S. (1998): MODFLOWP subroutine package for the computation of nonlinear confidence and prediction intervals on model parameters and parameter-dependent functions. Proceedings from MODFLOW'98 conference at Colorado School of Mines, October 4-8, 1998, Vol.1, p. 71-78. Editors: E. Poeter, C. Zheng & M.C. Hill. Published by Colorado School of Mines, Golden, CO.

Christensen, S. & R.L. Cooley (1998): Evaluation of prediction intervals for expressing uncertainties in groundwater flow model predictions. Abstract for 23rd General Assembly of EGS in Nice. Annales Geophysicae, Supplement II to Vol. 16, p. C 433.

Christensen, S. & K.R. Rasmussen (1998): Modelling regional groundwater flow using hydrogeological database information. Dept. of Earth Sciences Presentation Booklet in connection with the 23rd Nordic Geological Winter Meeting, Århus, 1998.

Dam, D. & S. Christensen (1997): Can K-ρ relations be estimated through ground water flow model inversion? Extended abstract for 3rd meeting on Environmental and Engineering Geophysics, September 3-6, 1997, Aarhus, Denmark.

Dam, D., Christensen, S., and Christensen, N.B., 1997: Hydraulic Modeling at Rokballe Test Site by Application of Geophysical Data. Proceedings of the Symposium on the Application of Geophysics to Engineering and Environmental Problems (SAGEEP), Reno, Nevada, 523‑529. (HYDRO‑TEM)

Christensen, S. (1996): Prediction of regional groundwater flow to streams. Abstract for the GSA 1996 Annual Meeting, Denver, USA, Oct. 28-31 1996.

Elberling, B. & S. Christensen (1996): Oxygen gas transport induced by atmospheric pressure fluctuation. Poster presented at the International Conference on Water Resources & Environment Research: towards the 21st Century, Kyoto, Japan, Oct. 29-31 1996.

Christensen, S. (1993): The influence of groundwater abstraction on the recharge and the stream runoff (Vandindvindingens indflydelse på grundvandsdannelse og vandløbsafstrømning, in Danish). In proceedings of the symposium "Grundvandsdannelse - kvantitet og kvalitet" in Lyngby, May 4th 1993. ATV-Committee associated with groundwater pollution, p. 17-32.

Christensen, S. (1987): Estimating Variations in Hydraulic Conductivity from Pumping Tests (Variationer i hydraulisk ledningsevne bestemt ved prøvepumpning, in Danish). In proceedings of the symposium "Vintermøde om grundvandsforurening" in Kolding, February 25-26 1987. ATV-Committee associated with groundwater pollution, p. 229-252.

Christensen, S. & K. H. Jensen (1986): Simulation of Subsurface Migra­tion of Organic Fluids. In proceedings of Nordic Hydrological Conference in Reykjavik, August 11-13 1986. Nordic Association for Hydrology, vol. 2, p. 623-639.

Jensen, K. H. & S. Christensen (1984): Simulation of Contaminant Transport from a Land Disposal Site - a case study. Appendix to proceedings of Nordic Hydrological Conference in Nyborg Strand, August 6-8 1984. Nordic Association for Hydrology, 10 p.

Jensen, K. H. & S. Christensen (1983): Simulation of groundwater contamination from a landfill site (Forureningsudbredelse fra en losseplads belyst ved en grundvandskvalitetsmodel, in Danish). In proceedings of the symposium "Grundvandsforurening - kilder, modeller, afværgeteknik" in Copenhagen, December 5th 1983. ATV-Committee associated with groundwater pollution.

 

 

Popular science papers:

Jeppesen, J., S. Christensen (2010): A tool for modelling LAR (In Danish: Et værktøj til hydrologisk modellering af LAR). Vand og Jord, vol. 17, no. 4, p. 128-130.

Christensen, S., N.E. Hansen, B.H. Jacobsen, K.R. Rasmussen & O. Schmidt (2003): The search for fresh drinking water – the valuable drops (Jagten på frisk drikkevand – de kostbare drabber, in Danish). MatematikFysikKemi i Perspektiv, Ed. N.E. Hansen, Fysikforlaget, vol. 2, no. 4, 8 p.

Christensen, S. (1998): Uncertainty of groundwater models (Grundvandsmodellers usikkerhed, in Danish). Geologisk Nyt, 1998, no. 2, p. 23-25.

Elberling, B., F. Larsen, S. Christensen & D. Postma (1998): Oxidation of pyrite in the Beder Aquifer, 2: Oxygene transport (Transport af ilt, in Danish). Vand & Jord, vol. 5, no. 2, p. 58-61.

Christensen, S. (1995): Groundwater Modelling (Grundvandsmodellering, in Danish). Contribution to  "Danmarks geologi fra kridt til i dag.", Ed.: O.B. Nielsen. Aarhus Geokompendier, vol. 1, Dept. of Earth Sciences, Aarhus University, p.193-214.

Raagaard, K. & S. Christensen (1992): Analysis of the management of groudnwater recovery works (Undersøgelse af eksisterende kildepladser, in Danish). Vandteknik, vol. 60, no. 8, p. 413-417.

Christensen, S. (1992): Water supply benefits from hydrological modelling (Vandforsyning og hydrologiske modeller, in Danish). Vandteknik, vol. 60, no. 4, p. 179-192.