Analysis of the sea bed scour and siltation to the west of Daishan channel, Zhoushan

Abstract

Abstract: Based on the underwater topography data of 1979,1996 and 2009, the scour and siltation of the tidal flat, subaqueous shore slope and deep trough to the west of Daishan channel were studied with GIS software for two different periods. The results show that the range of scour and siltation for the most part of the research area was ±1 m from 1979 to 1996, only part of the deep trough was more than 2 m; from 1996 to 2009, the scour and siltation of the tidal flat was similar to that from 1979 to 1996 with a range of -1 ~1 m, but the scour and siltation of the subaqueous shore slope and deep trough was obviously enhanced with an average range of 2 m for the slope and 3 m for the trough. Analysis show that there are two main reasons for the enhancement of the scour of the subaqueous shore slope and deep trough after 1996: the first one is the high flow speed of the Daishan channel and the clay bottom material, and the second is the construction of wharf and jetty at the tidal flat and subaqueous shore slope, which blocked the flow in the shallow water and increased the flow speed in the deep water, which enhanced the scour and siltation of the subaqueous shore slope and deep trough.

Key words: Daishan channel, tidal flat, subaqueous shore slope, scour and siltation

CLC Number:

TV148

SHEN Yuan, CHEN Rong-hua, ZHAO Qing-ying. Analysis of the sea bed scour and siltation to the west of Daishan channel, Zhoushan[J]. Journal of Marine Sciences, 2012, 30(2): 58-65.

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