Analysis of Superposition Influence Effect of Artificial Island Group on Coastal Dynamics in a Weak Tidal Zone

Abstract:

Focused on the influence of artificial island group on surrounding wa ve-current coupled hydrodynamics, a tidal current model and a wave model for Jingmeng Bay in Qinhuangdao, which had been well calibrated, were established to calculate the surrounding current and wave with the software MIKE21. Based on the analysis of hydrodynamic responses to artificial island group, some measurement points were selected to study the interaction between artificial islands. It can be founded that tidal current, due to resistance, guide and diversion functions by artificial islands, formed a large area of weak circulation between the Conch Island and shoreline, but it increased significantly in the inlet between the Lotus Island and Conch Island as well as the outer sea area of artificial island group. Current fields located in the three mentioned areas were largely affected by artificial islands, of which the Conch Island plays a controlling role. The changes of tidal current velocity, caused by artificial island group, were not satisfied with linear superposition of differences induced by each artificial island. However, the group influence on wave field is linearly summed by individual artificial island influence. The construction of artificial island group has advantageous in wave attenuation, but greatly weakens the tidal current in near-shore area.