Publication:
Discharge of nitrate-containing groundwater into a coastal marine environment

dc.contributor.author Andersen, Martin en_US
dc.contributor.author Baron, L en_US
dc.contributor.author Gudbjerg, J en_US
dc.contributor.author Gregersen, J en_US
dc.contributor.author Chapellier, D en_US
dc.contributor.author Jakobsen, R en_US
dc.contributor.author Postma, D en_US
dc.date.accessioned 2021-11-25T14:08:25Z
dc.date.available 2021-11-25T14:08:25Z
dc.date.issued 2007 en_US
dc.description.abstract The discharge of nitrate-containing fresh groundwater from a sandy coastal aquifer and into the adjacent shallow marine environment was investigated near Esbjerg at the northern end of the Wadden Sea in Denmark. The geological structure of the coastal site was determined from drilling data and geoelectrical methods such as multi-electrode profiling (MEP). The distribution of shoreface sediment containing freshwater was mapped using MEP, underwater multi-electrode profiling (UMEP) and the electrical conductivity measured on pore waters. Freshwater discharge fluxes were measured using seepage meters and estimated from observed head gradients and measured hydraulic conductivities in the aquifer sediments. The nitrate distribution in the coastal sediments was obtained from water samples. A groundwater flow model was established to quantify the groundwater flow and travel times, and the distribution of freshwater discharge along the coastline. Results show that on the watershed scale the fresh groundwater discharge is controlled by sand filled buried channels that connect the aquifer with the shoreface sediments. The freshwater discharge along the coastline is at this scale probably best estimated by the groundwater flow model. However, at a more detailed scale the distribution of freshwater discharge in the intertidal zone is controlled by small scale geological heterogeneity and models are unable to predict what happens at a small scale on the beach and offshore. For that purpose UMEP, seepage meters, pore water sampling and local hydraulic gradients are more useful. These measurements indicate that the freshwater discharge occurs in distinct zones and that the highest discharge is near the high tide line, decreasing rapidly in a seaward direction. Nitrate is abundant in the shallow groundwater of the coastal aquifer and is also present in the discharging fresh groundwater at certain patches along the coast. However, on average very little nitrate is observed in the fr en_US
dc.identifier.issn 0022-1694 en_US
dc.identifier.uri http://hdl.handle.net/1959.4/42087
dc.language English
dc.language.iso EN en_US
dc.rights CC BY-NC-ND 3.0 en_US
dc.rights.uri https://creativecommons.org/licenses/by-nc-nd/3.0/au/ en_US
dc.source Legacy MARC en_US
dc.subject.other submarine ground water discharge en_US
dc.subject.other geophysics en_US
dc.subject.other nitrate en_US
dc.subject.other coastal zone en_US
dc.subject.other coastal zone en_US
dc.title Discharge of nitrate-containing groundwater into a coastal marine environment en_US
dc.type Journal Article en
dcterms.accessRights metadata only access
dspace.entity.type Publication en_US
unsw.accessRights.uri http://purl.org/coar/access_right/c_14cb
unsw.identifier.doiPublisher http://dx.doi.org/10.1016/j.jhydrol.2006.12.023 en_US
unsw.relation.faculty Engineering
unsw.relation.ispartofissue 1-2 en_US
unsw.relation.ispartofjournal Journal of Hydrology en_US
unsw.relation.ispartofpagefrompageto 98-114 en_US
unsw.relation.ispartofvolume 336 en_US
unsw.relation.originalPublicationAffiliation Andersen, Martin, Civil & Environmental Engineering, Faculty of Engineering, UNSW en_US
unsw.relation.originalPublicationAffiliation Baron, L en_US
unsw.relation.originalPublicationAffiliation Gudbjerg, J en_US
unsw.relation.originalPublicationAffiliation Gregersen, J en_US
unsw.relation.originalPublicationAffiliation Chapellier, D en_US
unsw.relation.originalPublicationAffiliation Jakobsen, R en_US
unsw.relation.originalPublicationAffiliation Postma, D en_US
unsw.relation.school School of Civil and Environmental Engineering *
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