黄河三角洲岸线及现行河口区水下地形演变

根据实测的岸线和水深数据,利用Surfer 和Mapinfo 等软件进行数据处理,结合不同阶段利津站输沙量,分析了黄河三角洲岸线及现行河口区水下地形演变。结果表明:1953-2000年,68%左右的入海泥沙淤积在口门和滨海区。由于入海流路变迁,不同岸段的岸线变化具有各自的特征。刁口河流路以西岸线基本稳定;刁口河流路以东—孤东油田以北岸线经历先淤后冲,属于强侵蚀岸段,但在防潮大堤的保护下得到人为控制下的稳定;清水沟流路形成的岸线整体向海淤进,但清8 出汊后,清水沟老河口沙嘴南侧出现侵蚀。1976-1996 年,现行河口(清水沟流路) 水下地形总体上表现为淤积,顶坡段变缓,前坡段变陡。1996-2005 年,清水沟老河口水下地形顶坡段和前坡段发生侵蚀,底坡段呈现淤积;出汊新河口水下地形继续淤积,但程度和范围都比1976-1996 年的小。孤东油田近岸侵蚀加剧。

Evolution of Coastline and Subaqueous Geomorphology off the Survived River Mouth in the Yellow River Delta

Based on the measured data of coastline and bathometry,processed by software of Surfer and Mapinfo,and in combination with sediment load in different phases at Lijin gauging station,evolution of coastline and subaqueous geomorphology off the survived river mouth in the Yellow River delta is analyzed.The results show that ～68% of the sediment delivered by the Yellow River to the sea deposited in the river mouth and littoral area from 1953 to 2000.The changes of coastline in different coasts had a distinctive characteristic in response to transfers of river course into the sea.The coastline was stable in the coasts west of Diaokou river mouth.The coastline from the east of Diaokou river mouth to the north of Gudong oilfield had experienced siltation,and then serious erosion,finally kept stability with the conservation of sea walls.In general,the coastline at the survived river mouth of Qingshuigou river course stretched seaward,whereas the south side of sand spit at Qingshuigou old river mouth eroded after the Yellow River inpouring into the sea near the position at Qing 8.The subaqueous geomorphology off the survived river mouth exhibited siltation from 1976 to 1996,with flat topset beds and steeper foreset beds.From 1996 to 2005,the subaqueous geomorphology off the Qingshuigou old river mouth experienced erosion in the topset and foreset beds,but siltation in the bottomset beds.