九龙江口南港水位变化分析

On Water Level Change of the South Channel in the Estuary of Jiulongjiang River

根据石码站1980年以来多年潮位统计资料,分析九龙江口南港潮位变化及其原因.结果表明,近十多年来,南港低潮位持续下降,而高潮位变化不大,2005年平均潮差达4.0 m以上.大量挖取砂和径流量减少是导致低水位下降的主要原因.南港已成为受潮汐影响明显的河口潮流段,其深度基准面应按照海区性质,选用理论最低潮面.

The tidal level data of theShima Station since 1980 was used to study the water level change, together with its causation, of the South Channel in the estuary of Jiulongjiang River. It indicated that, over the past 10 years, the low tidal level of the channel went down continually, while the high tidal level nearly kept stable. This has led to the increasing of yearly mean tidal range, which was even more than 4m, in 2005. Excessive sand digging from the riverbed and runoff decline was mainly responsible for the drop of low tidal level. In view of the fact that the South Channel now belongs the estuarine tidal current reach, the theoretical lowest tidal level, according to the nature of sea area, should be used to calculate the depth datum plane for the channel.