Coastal sand barrier hydrology – observations from the BARDEX II prototype-scale laboratory experiment

Abstract

Turner, I.L., Rau, G.C., Andersen, M.S., Austin, M.J, Puleo, J. and Masselink, G. 2013. Coastal sand barrier hydrology – observations from the BARDEX II prototype-scale laboratory experiment In: Conley, D.C., Masselink, G., Russell, P.E. and O’Hare, T.J. (eds.), Proceedings 12 th International Coastal Symposium (Plymouth, England), Journal of Coastal Research, Special Issue No. 65, pp. 1886-1891, ISSN 0749-0208. The dynamics of groundwater at the land-ocean boundary has important implications to the exchange of water, nutrients and pollutants between the ocean and coastal aquifers, and varying groundwater levels may induce differing morphological response (erosion versus accretion) at the beachface. As a component of the Barrier Dynamics Experiment BARDEX II (Hydrolab IV) completed during June-July 2012 in the Delta Flume (The Netherlands), an extensive test program was undertaken to acquire a comprehensive data set of groundwater levels, pressure fluctuations, flow paths and tracer dispersion beneath the beachface and across the width of a prototype-scale sand barrier (D50 = 0.42mm). A particular feature of the experiment was the inclusion of a landward ‘lagoon’ and pump system that enabled the water levels on both the seaward and landward side of the barrier to be independently varied. The completion of these experiments complimented the previous BARDEX test program undertaken in the same test facility in 2008, where a gravel barrier (D50 = 10mm) was subjected to similar wave and lagoon-sea water-level conditions. An overview of the barrier hydrology instrumentation deployed and data obtained is provided here.