长江口深水航道30年空间特征变化研究

Analysis on the Siltation and Erosion before and after 1st Phase Engineering of the Deep Waterways during 30 Years in the Yangtze Estuary

根据1971-2003年6幅长江口海图资料,建立不同时期长江口深水航道水下数字高程模型,对航道治理前 后30 a的冲淤状况、纵剖面水深变化以及空间模拟等进行研究。结果表明,30 a来深水航道冲淤交替出现,总变化 趋势是冲刷。航道冲淤除与水动力条件有关外,与治理工程也有密切联系。长江口深水航道治理一期工程结束 后,水深明显加深,坡度比变大,主航道呈现平顺的“U”形河道景观。

Aeoording to the six charts of the Yangtze estuary from 1973 to 2003, the digital data are achieved using geographic information system;submerge digital elevation models of the deep waterways in different times are built up in this paper, On the basis of the data, the siltation and erosion, water depth of the vertical profile and spatial simulation are analyzed. The results show the general trend of the deep waterways is eroded in the thirty years,and the siltation and erosion appear at intervals. Besides relative to the hydro- dynamic condlitious,the changes of the siltation and erosion have close relationships with the channel regulation. Mter the completion of the 1st phase engineering of the deep waterways in the Yangtze estuary, the ratio of the channel gradient has became bigger, the depth of the channel has became deeper and the channel appears “U”.