温州瓯飞浅滩地形冲淤演变特征

Characteristics of erosion and deposition evolution of Oufei shoal in Wenzhou

基于瓯飞浅滩海域多年水文泥沙及地形水深实测资料,分析研究其水动力泥沙特性及地形冲淤演变规律。结果表明:研究海域潮流性质属于非正规半日浅海潮流,各垂线分潮流椭圆率K值在0. 00～0. 20之间,故潮流总体上以往复流为主;含沙量分布呈现外海向口内逐渐增大的趋势,且大潮期含沙量明显大于中潮和小潮期;通过对瓯飞浅滩近几十年的冲淤计算及相关断面分析,认为瓯飞浅滩的潮滩区域总体处于略有淤高基本稳定的状态。不同于潮滩区域,瓯飞浅滩的水下浅滩区域在1987—2010年,年均冲刷幅度为0. 008～0. 02 m,表现为基本稳定略有冲刷的状态。

Based on the observed data of hydrological sediment and the depth of terrain for many years in Oufei shoal,this paper analyzes the characteristics of the hydrodynamic sediment and the evolution of terrain erosion and deposition.The results show that the current in the study area are non-formal half-day shallow-sea tides,and K of the sub-stream ellipticity of each vertical line is between 0.00 and 0.20.Therefore,the current is dominated by reciprocating currents,and the distribution of sediments shows a gradual increase in the outer seaward direction.The sediment concentration in the tidal period is significantly greater than that in the mid-tide and the tidal waves.Through calculations of the scouring and siltation of Oufei shoal in recent decades and related cross-sectional analysis,it is known that the tidal flats in Oufei shoal are generally at a slightly high silt height.Unlike the tidal flat area,the underwater shoal area of Oufei shoal was from 1987 to 2010,and the average annual erosion rate was 0.008 to 0.02 m,showing a state of stable and slightly scouring.