疏浚工程对湄洲湾东吴港区水环境影响的数值模拟

Numerical Simulation of Water Environment Effects of Dredging Project in Dongwu Port Area of Meizhou Bay

为了解疏浚工程对附近海域水环境的影响,应用MIKE21软件,建立了湄洲湾港东吴港区工程附近海域的二维水动力和泥沙输运计算模型,在对潮流和悬浮沙计算结果验证可靠的基础上,分析工程对附近海域水环境的影响。结果表明,(1)疏浚工程对附近海域的潮流产生影响,流向更有利于靠离泊作业。(2)工程前后流速变小,码头栈桥区域周边流速最大可减小1.23 m/s,回旋水域流速最大可减小约0.59 m/s,东吴航道流速最大可减小约0.43 m/s;(3)悬浮沙浓度增量10 mg/L包络线的最远扩散距离为4.01 km,扩散面积为14.66 km^(2);施工结束后,悬浮泥沙恢复至一类水质的时长约3 h,恢复至本底值所需时长约16 h。

In order to understand the impact of dredging projects on the water environment of the nearby sea areas,a two-dimensional hydrodynamic and sediment transport calculation model for the sea areas near the Dongwu Port Area Project of Meizhou Bay Port was established using MIKE21 software.Based on the results of the calculation the tidal currents,tidal levels,and suspended sand were verified.The effects of the project on the water environment in the area were analyzed.The results show that:(a)The dredging project has an impact on the tide in the nearby sea area,which is conducive to the operation of mooring;(b)The flow rate before and after the project becomes smaller,the maximum flow rate around the dock trestle area can be reduced by 1.23 m/s,the flow rate of the roundabout water can be reduced by about 0.59 m/s,and the maximum length of the Dongwu waterway can be reduced by about 0.43 m/s;(c)The maximum diffusion distance of the suspended sand concentration increment of 10 mg/L envelope line is 4.01 km,and the diffusion area is 14.66 km^(2).After the completion of the construction,the time required for the suspension of sediment to return to Class I water quality is about 3 hours,and the time required to return to the bottom value is about 16 hours.