Holmgren Møller, F.

Skjøtt Linnberg, M.

Wahl, Niels Arne

Westergaard, M.

    Aalborg UniversitetModeling the impact of groundwater withdrawalSkjøtt Linnberg, M.; Holmgren Møller, F.; Wahl, Niels Arne; Westergaard, M.Published in:Geophysical Research AbstractsPublication date:2006Document VersionPublisher's PDF, also known as Version of recordLink to publication from Aalborg UniversityCitation for published version (APA):Skjøtt Linnberg, M., Holmgren Møller, F., Wahl, N. A., & Westergaard, M. (2006). Modeling the impact ofgroundwater withdrawal: a case study from northern Denmark. In Geophysical Research Abstracts EuropeanGeosciences Union.General rightsCopyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright ownersand it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.            ? Users may download and print one copy of any publication from the public portal for the purpose of private study or research.            ? You may not further distribute the material or use it for any profit-making activity or commercial gain            ? You may freely distribute the URL identifying the publication in the public portal ?Take down policyIf you believe that this document breaches copyright please contact us at vbn@aub.aau.dk providing details, and we will remove access tothe work immediately and investigate your claim.Downloaded from vbn.aau.dk on: April 26, 2017Geophysical Research Abstracts, Vol. 8, 00621, 2006SRef-ID: 1607-7962/gra/EGU06-A-00621© European Geosciences Union 2006Modeling the impact of groundwater withdrawal: acase study from northern DenmarkM. Skjøtt Linnberg (1), F. Holmgren Møller (1), N.A. Wahl (2) and M. Westergaard(1)(1) B study board, Aalborg University, (2) Dept. of Civil Engineering, Aalborg University(wahl@civil.aau.dk)The exploitation of the Danish groundwater resources is increasing and therefore thereis a continuously search for suitable well sites. Volsted Plantation, situated approx. 20km south of Aalborg in northern Jutland, is one such site, where a new battery of wellsmight be established in the near future. In the southern outskirts of Volsted Plantation,a fish farm is situated, producing disease free fish fry. A few artesian springs are thesole sources of water to the fish farm, with a discharge of approx. 1,55 mill. cubicmeters/y.This project investigates the impact of an annual groundwater withdrawal of approx.1 mill. cubic meters on the total discharge of the artesian wells. The deterministicgroundwater modelling system MODFLOW was used to determine the effect of thegroundwater withdrawal and resulting solute fluxes. Two scenarios were selected, dif-fering only in the fictive placement of the battery of wells, one (site 1) situated about800 m to the N of the fish farm and another one (site 2) about 1,300 m to the N of thefarm. A geologic model with five strata, with the lowest lying one comprising creta-ceous limestone and the other four strata primarily comprising glacial and postglacialsediments (sand with clay lenses) was made use of.The groundwater recharge of the modelling area was based on the base flow of thenearby stream, which was estimated to approx. 0.43 cubic meters/y. By using spa-tial land-use data, the groundwater recharge was differentiated spatially to amountbetween 0.27 and 0.59 cubic meters/y. The other parameters used in the model werethe hydraulic conductivity of the geological strata and the leakage coefficient for thestreams. The determination of the hydraulic conductivities was based on literaturevalues and pumping tests, carried out on experimental wells in the modelling area.The leakage coefficients for the streams were determined from extensive field tests,including profiles resulting from ground penetrating radar, drillings and slug-tests.Modelling parameters were calibrated and the groundwater recharge was set to a fixedrate.The result was a decrease in the water-flow through the fish farm. With the well site 1placed 800 m N of the fish farm, water flow decreased by approx. 30 %. With the wellsite 2 placed 1,300 m to the N of the farm, water flow decreased by approx. 15 %.This means that the production of disease free fish fry is threatened by the plannedgroundwater withdrawal, implying future production has to be altered to match thenew conditions. It is apparent that according to this investigation, the well site shouldproperly be placed the furthest away from the fish farm, as to minimize the withdrawalimpact. This should however be weighted against other relevant aspects such as pro-tective capabilities of the plantation and properly checked with the EU frameworkdirective under all circumstances.

Modeling the impact of groundwater withdrawal:a case study from northern Denmark

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Modeling the impact of groundwater withdrawal:a case study from northern Denmark

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