长江口深水航道工程对航道附近海域波浪分布特征的影响研究

Influence of Deepwater Channel Project on Wave Distribution in Sea Area near the Channelin Yangtze River Estuary

本文针对长江口深水航道工程建设前后航道内波浪特征的变化进行了分析研究,首先基于对长江口历史波浪资料分析,确定了E、NE和SE3个浪向为航道内典型代表,采用第3代波浪模型SWAN对工程建设前后的波浪进行模拟计算。研究表明,航道工程建设后航道内的有效波高和周期明显减小,但是其变化的规律基本一致。在不同天文潮影响时,航道内的有效波高和周期大不相同。E向和NE向的浪在大潮期间有效波高和周期均高于小潮时,SE向浪却相反。对于NE向的浪,航道工程对有效波高的影响大致呈现出从右向左逐渐减弱。对于E向和SE向的浪,航道工程对有效波高的影响大致呈现出从右向左先增强再减弱。航道工程对不同方向的浪在不同分段上也有所不同,在右段对NE向的消弱最强,对SE向最弱,在中段和左段对E向消弱最强,对NE向最弱。航道内流场与水位对波要素的影响也略有差别。

The changes in wave characteristics in the Yangtze River Estuary channel before and after the construction of deepwater channel project are analyzed.Based on historical wave data,the main wave di- rections within the channel are E,NE and SE.The wave model SWAN is used to simulate the waves before and after the proiect construction.The results show that thesignificantwave height and wave period are obviously reducedafter the construction of the waterway project.The regulations of the changes are roughly the same.With the effect of different astronomical tide,the significant wave height and period in the channel are quite different.The significant wave height and period of the E-direction and NE-direction wavesduring great tide are higher than those in small tide.For NE waves,the effect of channel engineering on the effective wave height is roughly reduced from right to left.For the E and SE waves,the effect of the channel engineering on the effective wave height generally enhances from right to left first and then weakens.The waves in different directions changes in different segments.The NE waves aremostly reduced in right segment,and the reduction is weakest for the SE waves in the middle and left segments.In the middle and left segments,the reduction is strongest for the intensity of E and weakest for the intensity of NE waves.The influence of flow field and water level on wave elements is also slightly different.