在河口与海洋交汇的河口地区都存在着一定范围的拦门沙浅滩，成为大型船舶通海航道的碍航区段。

In the convergence zone of the estuary and the ocean, there always exists the bar shoal which has become an obstacle to navigation for the large-scale vessels in seaward channel.

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目前上海港面临的主要问题是通海航道水深不能满足大型船舶进出港需要，上海深水港建设的紧迫性日益突出。

The key problem facing Shanghai Port is that the water depth in the waterways to the open sea is not enough to facilitate large vessels' entering and leaving the port.

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