Print Email Facebook Twitter Residual sediment fluxes in weakly-to-periodically stratified estuaries and tidal inlets Title Residual sediment fluxes in weakly-to-periodically stratified estuaries and tidal inlets Author Burchard, H. Schuttelaars, H.M. Rockwell Geyer, W. Faculty Electrical Engineering, Mathematics and Computer Science Department Applied Mathematics Date 2013-09-30 Abstract In this idealized numerical modeling study, the composition of residual sediment fluxes in energetic (e.g., weakly or periodically stratified) tidal estuaries is investigated by means of one-dimensional water column models, with some focus on the sediment availability. Scaling of the underlying dynamic equations shows dependence of the results on the Simpson number (relative strength of horizontal density gradient) and the Rouse number (relative settling velocity) as well as impacts of the Unsteadiness number (relative tidal frequency). Here, the parameter space given by the Simpson and Rouse numbers is mainly investigated. A simple analytical model based on the assumption of stationarity shows that for small Simpson and Rouse numbers sediment flux is down estuary and vice versa for large Simpson and Rouse numbers. A fully dynamic water column model coupled to a second-moment turbulence closure model allows to decompose the sediment flux profiles into contributions from the transport flux (product of subtidal velocity and sediment concentration profiles) and the fluctuation flux profiles (tidal covariance between current velocity and sediment concentration). Three different types of bottom sediment pools are distinguished to vary the sediment availability, by defining a time scale for complete sediment erosion. For short erosion times scales, the transport sediment flux may dominate, but for larger erosion time scales the fluctuation sediment flux largely dominates the tidal sediment flux. When quarter-diurnal components are added to the tidal forcing, up-estuary sediment fluxes are strongly increased for stronger and shorter flood tides and vice versa. The theoretical results are compared to field observations in a tidally energetic inlet. Subject channel flowscoastal flowsmixingtransportturbulencesingle column models To reference this document use: http://resolver.tudelft.nl/uuid:5cb8276a-7aa1-430c-a759-026a7b925da0 DOI https://doi.org/10.1175/JPO-D-12-0231.1 Publisher American Meteorological Society Embargo date 2014-03-30 ISSN 1520-0485 Source Journal of Physical Oceanography, 43 (9), 2013 Part of collection Institutional Repository Document type journal article Rights (c) 2013 American Meteorological Society Files PDF jpo-d-12-0231.1.pdf 4.71 MB Close viewer /islandora/object/uuid:5cb8276a-7aa1-430c-a759-026a7b925da0/datastream/OBJ/view