Numerical investigation of surge-tide interactions in the Bay of Bengal along the Bangladesh coast
Numerical investigation of surge-tide interactions in the Bay of Bengal along the Bangladesh coast
复制标题
孟加拉湾沿岸涌潮相互作用的数值研究
DOI：
10.1007/s11069-016-2711-4
复制
发表时间：
2017-03-01
期刊：
影响因子：
3.7
通讯作者：
Tajima, Yoshimitsu
中科院分区：
文献类型：
--
作者：
Hussain, Mohammad Asad;Tajima, Yoshimitsu
孟加拉湾沿着孟加拉国海岸的潮汐振幅从2米到7米不等，而潮汐相位从外部到Meghna河口内部相差3小时以上。气旋登陆时，潮相对风暴潮高度、到达时间和持续时间有显著影响。在本文中，在孟加拉湾沿着孟加拉国海岸的涌潮相互作用的性质进行了研究，使用二维非线性浅水模式与风暴潮模式耦合。孟加拉国海岸沿着先前发生的两次主要风暴潮事件（1991年气旋和2007年气旋锡德）已被分析为风暴潮-潮汐相互作用。为了研究潮汐阶段对涌浪特性的影响，除了基本情况外，还计算了整个潮汐周期中不同阶段每隔1小时的风暴潮。结果表明：在落潮时，潮波相互作用模型计算的总涌高高于将平均水位与当地潮位叠加计算的总涌高;在涨潮时，则相反。涌浪传播时间对海湾的内部显着变化，这取决于潮汐阶段。当海岸沿着的潮位较低时，涌浪的传播速度比潮位较高时慢得多。当下降的涌浪剖面在登陆位置遇到相反的强潮流时，涌浪持续时间增加。
The tidal amplitude at the Bay of Bengal along the Bangladesh coast varies from 2 to 7 m, whereas the tidal phase differs by more than 3 h from the outer part toward the inner part of the Meghna Estuary. At the time of cyclone landfall, the tidal phase has a significant impact on surge height, arrival time and duration. In this paper, the nature of surge-tide interactions at the Bay of Bengal along the Bangladesh coast has been investigated using a two-dimensional nonlinear shallow water model coupled with a storm surge model. Two previous major storm surge events along the Bangladesh coast have been analyzed for surge-tide interaction: Cyclone 1991 and Cyclone Sidr in 2007. To investigate the impact of the tidal phase on surge characteristics, in addition to the base cases, storm surges have been calculated at different phases of an entire tidal cycle at 1-h intervals. The results indicate that during the ebb tides the calculated total surge height of the surge-tide interaction model was higher compared to the total surge height obtained by superimposing surge height that is separately calculated with mean water level over the local tidal water level; the opposite occurs during high tide. The surge propagation time toward the inner part of the bay significantly varied depending on the tidal phases. When the tidal water level along the coast was low, the speed of surge propagation was much slower compared with when the tidal water level was high. The surge duration increases when the falling surge profile encounters an opposing strong tidal current at the landfall location.