详情

原文传递 Evaluating Transport Formulations for Application to Nearshore Berms

题名：	Evaluating Transport Formulations for Application to Nearshore Berms
正文语种：	eng
作者：	Rachel Bain;Brian McFall;Douglas Krafft;Austin Hudson
作者单位：	Coastal and Hydraulics Laboratory US Army Engineer Research and Development Center 3909 Halls Ferry Rd. Vicksburg MS 39180;Coastal and Hydraulics Laboratory US Army Engineer Research and Development Center 3909 Halls Ferry Rd. Vicksburg MS 39180;Coastal and Hydraulics Laboratory US Army Engineer Research and Development Center 3909 Halls Ferry Rd. Vicksburg MS 39180;Portland District US Army Corps of Engineers 333 SW First Ave. Portland OR 97204
摘要：	Dredged sediment is commonly placed as a submerged nearshore berm to nourish the beach or to dissipate high-energy waves, but the lifespan of such features is not easily predicted by existing methods. This paper presents a simple technique for generating order-of-magnitude estimates of the sediment transport rate of nearshore berms using offshore hindcast wave characteristics transformed to the nearshore. Total longshore transport for the entire nearshore region is calculated using eight published longshore transport equations (e.g., CERC equation and Kamphuis equation), which were evaluated for their relative performance. Because nearshore placements occupy only a portion of the cross-shore profile, the total longshore transport rate is scaled by an empirically-based fraction between 0 and 1, which is determined by the nearshore berm's position in nondimensional space. The cross-shore transport rate is calculated independently using the near-bed orbital velocity from stream-function wave theory. The longshore and cross-shore transport rates are then superimposed to generate a total transport rate for the near-shore berm's constructed footprint. The total transport rates were calculated at 11 historical nearshore berms and evaluated based on accuracy, inclusion of relevant coastal processes, and sensitivity to input parameters. The recommended total transport rate technique resulted in an average percent error magnitude of 72% and a maximum percent error magnitude of 167% at the historical placement locations. This technique is recommended for generating rapid, order-of-magnitude estimates of nearshore berm deflation rates for project design, particularly in scenarios when application of a full numerical model is prohibitive.
出版年：	2021
期刊名称：	Journal of Waterway, Port, Coastal and Ocean Engineering
卷：	147
期：	6