黄河清水沟流路大嘴的形成对莱州湾潮流场影响的数值研究

Numerical Study on Effects Given to Tidal Current Field in Lai Zhou Bay by the Wide Mouth of Yellow River Estuary Formed From Qingshui Gully

黄河口于1976年改道清水沟流路入海，入海河沙淤进致使莱州湾西岸局部岸线向海推进约21km，在0，5，10m等深线处分别向海推进21，17，16km。按黄河口改道清水沟流路前和改道后的莱州湾岸线和海底地形分别建立模型，计算了黄河口改道前后的莱州湾潮流场。结果表明，黄河大嘴的形成，致使其两侧涨落急计算流速减小了40cm／s之多，其东侧形成一个东西宽约8km、南北长6km的流速增大区，该流速增大区涨落急时刻计算流速较改道前增大30cm／s以上；莱州湾西部海域计算主流向偏转，偏转量在27°～108°之间；清水沟流路大嘴形成前后，莱州湾东部潮流场变化不明显。

The Yellow River Estuary became displaced and relocated in 1976 at the place where the Qingshui Gully used to flow into the sea. Because sands are carried from the Yellow River Estuary and deposited in the Laizhou Bay, the coastline has had a displacement about 21 km toward the sea. The 0 m, 5 m, and 10 m isobaths have respectively moved 21 km, 17 km, and 16 km seaward in the bay. The coastline and the bottom topography respectively for the pre-relocation conditions and for the post-reloction condi- tions of the Yellow River Estuary are considered in the established model to compute the corresponding tidal current field in the Laizhou Bay. It is shown in the simulation results that either the flood strength or the ebb strength becomes 40 cm/s slower at the both sides of the estuary mouth, after the wide mouth of the Yellow River Estuary has been formed at the Qingshui Gully. There appears an area about 8 km（from the east to the west）×6 cm（from the north to the south） in the east side of the Laizhou Bay, where the tidal current speeds become increased, and the flood strength or the ebb strength becomes 30 cm/s greater. The main current directions become 27°～108° deflected in the west of the bay. The tidal currents are not changed much at the other places in the east of the bay.