象山港航道冲淤变化初步分析

Preliminary Analysis of Scour and Accretion on the Seabed in the Navigation Channel of Xiangshan Bay, Zhejiang Province, China

利用象山港海湾不同年份的水深地形资料，运用GIS技术采用航道轴线剖面水深地形叠加对比和海床平面冲淤计算相结合的方法，应用以往水文泥沙等资料综合分析象山港航道区域的冲淤变化。结果表明40a来象山港航道区域总体冲淤基本平衡，大致以双德山附近海域为界，以东牛鼻山浅段和西屿山-双德山深段两区段以微淤为主，平均厚度分别为0．08—0．24m和0．51—0．58m，并具有缓慢淤积的趋势；以西的浅段和深段则以微冲为主，平均厚度为0．32—0．62m，并具有轻微冲刷的趋势。

Utilizing the historical topographic maps of Xingshan Bay, adopting the method of comparing the topographical longitudinal-profiles of different years in navigation channel center and calculating the scour and accretion on the seabed in the navigation channel area by GIS technology, this paper synthetically analyses the scour and accretion character on the seabed in navigation channel of Xiangshan Bay with the previous data of hydrology and suspended sediment concentration in the field. The result suggests that the navigation channel is in equilibrium with the scour and accretion in the recent 40 years on the whole, and this navigation channel can be divided approximately into two that is, of the east and west to Shuangde islands. In the eastern area, Niubi Shan shallow segment and Xiyu-Shuangde depression segment underwent slight accretion with average thicknesses of 0.08 to 0.24 m and 0.51 to 0.58 m respectively, and both tend to silt. The shallow and depression segments in the west all experienced slight scour with an average thickness of 0.32 to 0.62 m area, and had a tendency of scour.