连云港海域悬沙和表层沉积物交换研究

采用粒度谱计算方法分析连云港及邻近海域悬沙和表层沉积物交换特征，为徐圩防波堤口门布置和连云港港航道回淤研究提供理论支撑。连云港港主航道和徐圩航道5 m等深线以外的区域悬沙和表层沉积物交换率为0.1~0.2，表明航道回淤强度将处于较低水平，对今后航道维护有利；5 m等深线以内区域的交换率为0.3~0.4，悬沙落淤对航道回淤有一定贡献，表明该航道段回淤量相对较大，计算结果与实测航道回淤强度分布特征基本一致。灌河口沙嘴正常天气条件下交换率小于0.2，说明悬沙落淤对沙嘴的影响较小；5 m等深线以内破波带水域交换率大于0.5，表明悬沙和表层沉积物交换频繁。连云港港及邻近海域悬沙和表层沉积物交换主要为粒径小于62 μm的细颗粒组分。分析结果表明，为减少泥沙回淤对徐圩港区港池正常运行的影响，兴建防浪挡沙堤并将堤头布置在破波带之外十分必要。

Analysis of exchange of suspended and surface sediments in Lianyungang harbor and adjacent sea waters

The analysis of the exchange of the suspended and surface sediments in the Lianyungang harbor and adjacent sea area was carried out based on the grain-size spectral calculation method, which provides a theoretical basis for the general layout of the breakwater entrance in the Xuwei port and the siltation research on the navigation channels in the Lianyungang harbor. From the calculated results it is found that the sediment exchange ratio in the main Lianyungang navigation channels and Xuwei navigation channels 5 m outside the isobaths is between 0.1 and 0.2, and the siltation intensity is relatively low, which is beneficial to the channel maintenance. The exchange ratio in the navigation channel 5 m inside the isobaths is between 0.3 and 0.4, and the suspended sediment deposition adds a contribution to the channel siltation. It indicates that there is a greater sedimentation in the section of this navigation channel. And the calculated results are consistent with the distribution characteristics of the measured siltation intensity, being a scientific basis for further researches on the channel siltation and maintenance. The sediment exchange ratio of the sand spit in the Guanhe River estuary is below 0.2 under the normal climate conditions. The sediment exchange ratio in the surf zone 5 m inside the isobaths is more than 0.5, which indicates that the suspended and surface sediments exchange occurrs frequently. The particle size components of the sediment frequently exchanged are the fine particle size sediment ( < 62 μm). The analysis results show that it is necessary to construct a sediment barrier and its head should be placed outside the surf zone for reducing influences of siltation on the normal port operation. The above results provide a case study for applying the grain-size spectral calculation method to the harbor and waterway engineering.