瓯江南口外浅滩含沙浓度特征

Characteristics of sediment concentration variations in offshore area south of the Oujiang Estuary

基于2010年10月瓯江南口外浅滩的泥沙实测资料,对含沙浓度的时空变化进行了分析研究。利用非线性最小二乘法拟合出了新的含沙量公式,并与刘家驹公式在不考虑波浪作用下的简式作比较,对新公式的适用性进行了探讨。分析结果表明:(1)含沙浓度从瓯江南口门向外海逐渐减小,沿岸方向的变化则存在大、中、小潮差异;(2)垂向上,含沙浓度由表层向底层逐渐增大;(3)含沙浓度具有大潮最大、中潮次之、小潮最小的特点,涨潮含沙浓度基本大于落潮含沙浓度;(4)与刘家驹公式相比,新公式的拟合结果与实测含沙量的相对误差较小,相关性较高。

Based on the measured data of sediment in offshore area south of the Oujiang Estuary in Oct. 2010, temporal and spatial variations of the sediment concentration were studied. A new sediment concentration formula was fitted by nonlinear least square method. Compared with the simple format of the Jiaju Liu formula ignoring the effect of wave, the applicability of the new formula was discussed. The results show that （1） sediment concentration decreases gradually from the south mouth of the Oujiang river to open sea. It is different during spring tide, middle tide and neap tide along the coastline; （2） sediment concentration increases gradually from surface to bottom in the vertical direction; （3） sediment concentration in spring tide is the highest, and higher in middle tide, and low in neap tide. It is higher in flood tide than that in ebb tide; （4） compared with the simple format of the Jiaju Liu formula ignoring the effect of wave, the fitting result of the new formula is highly related to the measured data of sediment concentration, and the relative error is small.