長江口南槽近期河床演變及航道淤淺原因分析

摘要

利用1998年以来的多次水下地形资料及现场水文观测资料，结合周边涉水工程情况，分析了长江口南槽近期的河床演变特点。结果表明：①南槽上段冲刷、下段淤积；②拦门沙浅段缩短淤高，年内“洪淤枯冲”；③江亚南沙体积增大、沙尾下延。在此基础上，探讨了近期南槽下段航道局部区段的淤浅原因，结果表明，其原因主要是江亚南沙沙尾在南槽河段整体滩槽格局条件下的自然淤涨下延、侵入航槽。%Using multiple underwater terrain material and field hydrological observation data , then combining with the surrounding project progress , the recent evolutional process and channel siltation reasons of the South Passage are analyzed . The results show that: ①South Passage scours in the upper segment , and deposits in the lower ; ②the mouth bar of South Passage gets shortened and riverbed gradually raises ; ③ the volume of Jiangya ’ nansha Shoal increases , and the empennage of the shoal extends to downstream . Preliminary analysis suggests that :the natural deposition extension of Jiangya ’ nansha Shoal is the primary cause of channel siltation .