Print Email Facebook Twitter Modelling sediment transport and morphology during overwash and breaching events Title Modelling sediment transport and morphology during overwash and breaching events Author De Vet, P.L.M. Contributor Stive, M.J.F. (mentor) Den Bieman, J.P. (mentor) McCall, R.T. (mentor) Talmon, A.M. (mentor) Visser, P.J. (mentor) Yuan, J. (mentor) Faculty Civil Engineering and Geosciences Department Hydraulic Engineering Programme NUS-TUD Double MSc Degree Programme Date 2014-08-20 Abstract Currently, morphodynamic models as XBeach show substantial overestimations of the erosion rates during breaching and overwash events at barrier islands. The presently used limitations on the Shields parameter and the sediment concentration do hinder erosion, but have undesirable side effects, e.g. the breaching process is suppressed. By implementing additional physics, e.g. the erosion hindering effect of dilatancy and a proper bed slope effect, substantial improvements are achieved for idealised cases. However, two hurricane case studies showed that these model improvements do not hinder erosion sufficiently to achieve reasonable results. A proper description of bed roughness, which is preferably depth dependent and accounts for vegetation, together with calibration of the wave skewness and asymmetry is found to be very important. If this knowledge is applied on a newly introduced case study of Fire Island (hurricane Sandy, 2012), both breaching and overwash are modelled much more in line with reality. However, the complexity of having various morphodynamic processes within one model domain makes calibration a challenging task, requiring a more advanced bed roughness formulation. Subject BreachingOverwashModellingFire IslandHurricaneSandyXBeach To reference this document use: http://resolver.tudelft.nl/uuid:d4e21d44-fcef-498b-b2e5-83df3b0e0c47 Coordinates 40.723521, -72.896395 Part of collection Student theses Document type master thesis Rights (c) 2014 De Vet, P.L.M. Files PDF MScThesis_Lodewijk_de_Vet.pdf 9.34 MB Close viewer /islandora/object/uuid:d4e21d44-fcef-498b-b2e5-83df3b0e0c47/datastream/OBJ/view