A correction for Dupuit-Forchheimer interface flow models of seawater intrusion in unconfined coastal aquifers
Number of Authors: 4
2015 (English)In: Journal of Hydrology, ISSN 0022-1694, E-ISSN 1879-2707, Vol. 525, 277-285 p.Article in journal (Refereed) Published
Interface flow models that use the Dupuit-Forchheimer (DF) approximation for assessing the freshwater lens and the seawater intrusion in coastal aquifers lack representation of the gap through which fresh groundwater discharges to the sea. In these models, the interface outcrops unrealistically at the same point as the free surface, is too shallow and intersects the aquifer base too far inland, thus overestimating an intruding seawater front. To correct this shortcoming of DF-type interface solutions for unconfined aquifers, we here adapt the outflow gap estimate of an analytical 2-D interface solution for infinitely thick aquifers to fit the 50%-salinity contour of variable-density solutions for finite-depth aquifers. We further improve the accuracy of the interface toe location predicted with depth-integrated DF interface solutions by similar to 20% (relative to the 50%-salinity contour of variable-density solutions) by combining the outflow-gap adjusted aquifer depth at the sea with a transverse-dispersion adjusted density ratio (Pool and Carrera, 2011), appropriately modified for unconfined flow. The effectiveness of the combined correction is exemplified for two regional Mediterranean aquifers, the Israel Coastal and Nile Delta aquifers.
Place, publisher, year, edition, pages
2015. Vol. 525, 277-285 p.
Coastal aquifer, Seawater intrusion, Submarine groundwater discharge, Sharp interface, Outflow gap, Transverse dispersion
Civil Engineering Earth and Related Environmental Sciences
IdentifiersURN: urn:nbn:se:su:diva-119182DOI: 10.1016/j.jhydrol.2015.03.047ISI: 000355885600022OAI: oai:DiVA.org:su-119182DiVA: diva2:844858