Abstract

Tidal hydrodynamics of the Gulf of Khambhat (GoK) were studied with the observed and simulated datasets. The flushing time of the Gulf was estimated using the 2D-model calibrated and validated with the tide and current speed observations. Model simulations were carried out with the influence of tide, wind, and tide and wind combinedly. Wind-driven flushing was found to be the least with the flushing time magnitude of more than 25 days. The flushing time was found to be much lower for the surrounding sea irrespective of the seasonal and tidal variations. The model-derived tidal circulation revealed the seasonal variability and the dominance of flood tide over ebb in GoK. Maximum current speed was during spring-flood conditions in the southwest monsoon, whereas minimum current speed was during the neap-ebb condition of pre-monsoon. High-frequency radar data, from the southern GoK ascertain the increase in current speed from south to north. The Simpson–Hunter parameter, calculated in several locations of the Gulf established the enhancing mixing capacity of GoK from south to north. During low current speed conditions, the Gulf experiences the formation of a barrier at the southern region which interrupts flushing between the Gulf and the north-eastern Arabian Sea during northeast monsoon and pre-monsoon season.

Highlights

• Tidal hydrodynamics of Gulf of Khambhat studied with the observed and simulated datasets

• Amplification in the mixing capacity of the Gulf is observed towards the north

• Least flushing was observed during pre-monsoonal months

中文翻译：

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印度西海岸Khambhat湾的潮汐流体动力学和冲刷特征——数值方法

摘要

使用观测和模拟数据集研究了康巴湾 (GoK) 的潮汐流体动力学。使用经过潮汐和水流速度观测校准和验证的 2D 模型估计海湾的冲洗时间。模型模拟是在潮汐、风和潮风相结合的情况下进行的。发现风驱动冲洗最少，冲洗时间超过25天。发现无论季节和潮汐变化如何，周围海域的冲洗时间都要短得多。模型导出的潮汐环流揭示了 GoK 的季节性变化和洪水退潮的主导地位。最大水流速度出现在西南季风春季洪水期，而最低水流速度出现在季风前期小潮期。来自 GoK 南部的高频雷达数据确定了当前速度从南到北的增加。在海湾的几个位置计算的 Simpson-Hunter 参数确定了 GoK 从南到北增强的混合能力。在低水流条件下，海湾在南部地区形成一道屏障，在东北季风和季风季节期间中断了海湾与阿拉伯海东北部之间的冲刷。

强调

• 使用观测和模拟数据集研究了康巴湾的潮汐流体动力学

• 向北观察到海湾混合能力的放大

• 在季风前几个月观察到的潮红最少