近30年吕四海域地貌冲淤规律及机制分析

Analysis of the law and mechanism of the erosion and deposition of the Lvsi area in recent 30 years

本文基于吕四港海域1989—2019年不同时期的水深地形资料,选定研究区域面积是34 369 m^(2),建立研究区域的DEM模型,通过Kringing插值和数理统计定量探讨不同地貌的冲淤演变规律。研究结果表明:近30年来,研究区域的水下地形已由淤积向侵蚀转变,1989—2006年淤积总量是0.54亿m^(3),2006年以后,水下地形出现侵蚀,侵蚀总量维持在-0.05~-0.13亿m^(3),一方面是因为长江流域和苏北沿岸的输沙率减少,造成区域的来沙量减少,另外一方面是因为沿岸围涂工程实施,改变了研究区域的潮流水动力变化。

Based on the hydro-topographical data of the area from 1989 to 2019,the study area is 34369 m^(2).Establishing the DEM model,the paper used Kriging Interpolation and mathematical statistics to quantitatively analyze the mechanism of the erosion and deposition of Lvsi area.The results showed that the subsea terrain of Lvsi Area had turned from deposition to erosion in the past 30 years.The total sediment deposition volume was 54 million cubic meters from 1989 to 2006.The erosion started since 2006,and the total volume of the eroded sediment had been maintained between-5 and-13 million cubic meters.On the one hand,the erosion was attributed to the decreasing of the regional sediment supply due to the declining of the rate of sediment transport in Yangtze basin and along the coastline of northern Jiangsu.On the other hand,the hydrodynamic change of current and tide due to the reclamation projects along the coastline also caused the erosion.