浙南地区潮汐特性长期变化趋势研究

Study on the long term trends of tidal change characteristics in south Zhejiang Province

近几年监测数据显示,浙南地区潮汐规律正发生改变,为研究其变化趋势,本文利用Mann-Kendall和BG分割算法等方法,对温州、瑞安、鳌江3个站点近60年潮位资料进行分析。结果表明:浙南沿海地区潮汐特性发生很大变化,平均高潮、平均潮差有增高、增大趋势,平均低潮正逐渐降低,涨潮时间变长,落潮时间缩短,且各站点潮汐特征变幅不同,其中温州站平均高潮变幅最小,平均低潮、平均潮差变幅最大,鳌江站涨落潮历时变幅最大。研究发现潮汐特性发生突变的时间与河道挖沙、滩涂围垦等人类活动加剧的时间段相吻合,这表明河道挖沙、滩涂围垦是引起潮汐特性变化的主要因素。

The observed data in recent years indicated that, some changes of tidal characteristics have taken place in south Zhejiang province. In order to study its variation trends, the tidal features were analyzed based on the data observed in Wenzhou, Ruihn and Aojiang stations in recent 60 years by the Mann -Kendall test and the Bernaola- Galvan （B -G） segmentation algorithm. The results showed that a great change has taken place to the tidal characteristics in south Zhejiang province. Both the average high tidal level and tidal range increased, while the average low tidal level decreased gradually, meanwhile the flood - tide duration increased and the ebb - tide duration shortened. The change amplitudes of the tidal characteristics at the three stations were different. The smallest variation of the average high tidal level was at Wenzhou station, and the biggest variations of the average low tidal level and tidal range wre at Wenzhou station. But the biggest variation of the flood - tide duration was at Aojiang station. This analysis showed that the time of mutation of the tidal characteristics agreed with the period of increasing human activities such as sand excavation and tideland reclamation. This meant that human activities are the main factor which caused the tidal characteristics change.