Empirical Equilibrium Beach Profile Formula of Sandy Beach with a Single Sandbar

Abstract:

Based on the beach profile survey data after the beach nourishment project on the coast between the Daihe Estuary and the Yanghe Estuary， the sandy beach under the low-energy condition with a single offshore sandbar was selected to investigate its morphological evolution process. A new equilibrium profile function with a single bar， which is comprised of background profile and barred profile， is derived. The background profile is based on the principle of maximum entropy to consider the difference between onshore and offshore side of the beach profiles， while the barred profile is described by 3 to 4 parameters to show the asymmetric sandbar shape in the form of parabolic function. The new shape function fits well with the measured post-nourishment beach profile from the Daihe Estuary to the Yanghe Estuary， which also has been successfully applied to the Tiger-Rock Beach in Qinhuangdao and the Fort Myers Beach in Florida. It indicates that the new shape function can accurately reflect the characteristic of the low-energy beach with a single sandbar.