Prediction of Formation of Sand Spit on Coast With Sudden Change in Coastline Using Improved Bg Model

Numerical Simulation of Elongation of Sand Spit on Seabed With Different Water Depths and Slopes

“…The BG model proposed by Serizawa and Uda (2011) with an additional term from Ozasa and Brampton (1980) was used in the numerical simulation. The fundamental equations are given as…”

“…In recent studies of the development of the sand spit, Ashton et al (2001) showed that shoreline instability may develop and the sand spit can emerge from a small perturbation under oblique wave incidence with the angle between the direction normal to the shoreline and the wave direction being larger than 42°. Serizawa and Uda (2011) numerically simulated the development of the sand spit using the BG model (a three-dimensional model for predicting beach changes based on Bagnold's concept), and their results were compared with the results of a movable bed experiment with a model scale of 1/100 under the conditions that the coastline orientation abruptly changes on the shallow seabed and a steep slope extends along the corner where the coastline orientation changes. They successfully explained the formation of a sand spit and a barrier.…”

Prediction of Beach Changes Around Artificial Reef Using Bg Model

“…The BG model proposed by Serizawa and Uda (2011), in which Bagnold's concept (Bagnold, 1963) is used, was improved, taking both the wave field and the current velocity at a local point into account. The fundamental equations of the model are given by Eqs.…”

“…The effects of these currents were not considered in the previous BG model (Serizawa and Uda, 2011), which employed only the wave field without calculating the nearshore currents, although the effect of longshore currents was implicitly considered in the sand transport equation described using the local wave characteristics. In this study, the effect of the nearshore currents induced by forced wave breaking was incorporated into the model by calculating the nearshore currents using the method by Horikawa (1988).…”

“…In this study, we improved the BG model proposed by Serizawa and Uda (2011) by incorporating the effect of not only waves but also strong nearshore currents into the model, as well as increase in the depth of closure due to the strong currents. Then, we applied the model to the Kaike coast.…”