Numerical Simulation On Random Wave-Induced Erosion And Deposition Evolution In The Heini Bay

Coastal zone and offshore area are the habitat of human activities. Its characterof erosion and deposition is of important meaning to sedimentary environment andoceanographic engineering. And in general, offshore area is the typical region of thecombined effect of wave and tidal current. To consider complicated characteristics ofwave and current condition of alongshore waters, deviation may be brought intosimulation result of seabed evolution if only current factor is taken into account.Based on simulated tidal current field, how to modeled erosion and deposition byintroducing wave effects is the core problem of the oceanographic engineering study.Heini Bay is located in the southeast of Shandong Peninsula. It is the typical sea areaof nearshore development and utilization(Shidao Bay nuclear plant, laminaria culture),having good social and economical benefits, as well as academic meaning.In this paper, according to the local statistical characteristics of wave field, therandom wave factor was analyzed and coupled to simulate seabed erosion andaccretion in the Heini Bay based on ECOMSED model. The simulated result of tidalcurrent field agrees with the in-situ observation data well. The results show that thereis a stable N-S tidal residual current in the Heini Bay and adjacent areas which is keyfactor to sediment transportation. The seabed erosion-accretion pattern is related totopography and current velocity and wave field. During the simulation The seabed isrelatively stable with except for erosion outside in the Chu and Moye islands andaccretion in northern and southern Moye island. The simulating result is more close toevidence from sea chart comparison if the random wave field is coupled analyzed.Based on a hypothesis, By wave momentum transmission theory the wavetransmission coefficient under the condition of kelp farm was found out. The resultingcoefficient was used to develop a wave model suitable for the sea area to explore theeffect of kelp farm on wave field and seabed erosion-accretion pattern. The results ofnumerical simulation show that the intensity of deposition and erosion decrease by 20%to30%.