Influence Of Offshore Artificial Island On Sandy Coastal Evolution

Artificial island reclamation is a way to develop and utilize marine space resources,which can effectively reduce damage to natural shoreline resources and coastal ecological landscape.However,the formation of artificial island also affects the regional ocean water exchange,submarine topography and nearshore shore stability.Therefore,it is very important to arrange the artificial island reasonably.This paper has carried out the research on the deformation of the bank at the rear of the artificial artificial island.Artificial island design,site selection and control of environmental impact may have important practical significance.The sandy coast of this study is located between the Dingziwan Bay and the Mahegang Harbor in Haiyang City,and is formed by the two estuaries.Under the present conditions,the sandy coast is the sediment-bearing equilibrium state of SW-NE,and the sediment along the sediment is willing to move towards NE and the sediment transport is small.Artificial island is located in the sandy coast in front of 1.3km sea area,in the northeast side of the tidal delta deep tide,the depth of 3.0 to 5.0 between.In this paper,MIKE21 numerical model is used to simulate the wave field,tidal current field and scouring and silting environment changes before and after artificial island formation.The results show that the artificial island is formed in the wave area,and the wave field and direction distribution in the waters near the study area are changed.After the formation of the artificial island,the cross section of the high tide channel between the island and the sandy coast decreases,Flow under the combined effect of the island after the deposition of the shadow area to strengthen the erosion of both sides of the shadow area.The MEPBay and LITLINE models were used to predict the evolution of the sandy coast.After the formation of the artificial island,the evolution trend of the sandy seaside was in the middle of the sea.The LITLINE model predicts that the maximum distance from the siltation to the sea will be 176.8 m after 20 years of artificial island formation.The sediment transport rate in the south section is 0.92 × 104 m3 / a,1.16 × 104 m3 / A,the direction of sediment transport from the SW to the NE direction,the north side from the maximum silting point closer to the section of the sediment transport rate of 0.02 × 104 m 3 / a,the direction of the direction of the direction of the NE from the NE to the SW direction.Combined with the empirical formula,the trend between the coast and the artificial island is formed,but the strong fluctuation trend between the island and the island has a certain inhibitory effect on the formation of the island dam.Based on the LITLINE model,the paper forecasts the reduction of the coastline of the artificial island to the length of the main wave to the crest line and the increase of the offshore distance scheme.The results show that the shorter the projected length of the artificial wave in the main wave direction,the farther away from the offshore,the smaller the volume of the sea,and the smaller the possibility of forming the island sand.