Seabed Erosion and Deposition Formulas Applied to a 2D Hydrodynamic Harbor Engineering Simulation

In coastal engineering, predicting seabed erosion and deposition can help understand hydrodynamic changes of the coastal area. The present work aims to address the prevalent challenge that there is often a shortage of measured data in coastal areas. In this paper, a new seabed erosion and deposition formula with four forms is proposed and combined with 2D hydrodynamic harbor engineering simulation of Daishan Island situated in Zhejiang province, China. The simulation shows that (1) in the open channel, the proposed new formula considers the friction coefficient before and after trenching, thus providing a more accurate prediction result; (2) in the sheltered channels, the proposed new formula can roughly estimate the deposition intensity; (3) in the basin entrance, the proposed new formula provides an estimation better aligned with reality than existing formulae. Meanwhile, the recovery saturation coefficient is not a constant; it can be set at 0.31 in the obtained formulas for calculations during the back silting, and at 0.11 during scouring. Therefore, the proposed new formula provides an improved solution to prediction of seabed erosion and deposition and is applicable to Daishan coastal area in different situations.