不同围填海方案对南黄海辐射沙脊群海域的冲淤影响研究

Study on reclamation impact on sedimentary erosion and deposition in radial tidal sand ridge system in the South Yellow Sea

本文采用MIKE21二维水动力模型模拟了南黄海辐射沙脊群海域的潮流形态,模拟结果与实测潮流基本一致.在此基础上,比较了三套不同围填海方案对工程附近区域的冲淤影响.从整体上看,三套方案都会对工程周边海域的海底冲淤产生明显影响.条子泥围填海工程后在其北部产生淤积,在东南部产生冲刷.东沙和高泥两座人工岛的建成使原本以弶港为中心扇形辐聚、辐散的潮流格局有所改变,潮流进出主要集中在西洋水道南端和黄沙洋水道西端这两条潮流通道,通道内流速增大,产生冲刷;而两人工岛东部和弶港东部海域产生淤积.基于目前的模拟结果,只建设高泥和东沙两座人工岛更有利于维持西洋水道和黄沙洋水道的畅通,对近岸港口资源具有保护作用.

In order to study the reclamation impact on sedimentary erosion and deposition by reclamation projects in the radial tidal sand ridge system in the South Yellow Sea,the two-dimensional hydrodynamic model,MIKE21,was applied to simulate the tidal currents,and erosion and deposition were calculated using empirical formula.Then the sediment erosions and depositions caused by different kinds of reclamation projects were calculated.Three cases of reclamation project were numerical tested.They were Tiaozini reclamation project（Case 1）,Dongsha and Gaoni reclamation project（Case 2）,and Case 3was a combination of Case 1and Case 2.All the three cases showed obvious impacts on the sedimentary erosion and deposition.In Case 1,sedimentary deposition occurred on the north of Tiaozini and erosion occurred on the south of it.In Case 2,the fan-shaped,Jianggang centered tidal current system was changed,and the tidal currents were constrained to the two water channels of Xiyang and Huangshayang,which induced velocity increasing and sedimentary erosion in the channels,while depositions occurred at the east of Dongsha and Gaoni.In Case 3,the erosion and deposition areas were similar to the combined impacts of the former cases.Based on the model results,Case 2was the appropriate case for keeping the tidal channel unimpeded and protecting the harbor resources.