近岸悬沙垂线分布多元线性回归分析

Multiple linear regression analysis of vertical distribution of near-shore suspended sediment

许多学者在研究河口近岸水域时常采用扩散理论Rouse方程描述泥沙垂线分布规律,本文结合该方程成立的几个主要假设,分析该方程在近岸地区的适用性。在传统的Rouse分布基础上借助Rouse方程的线性形式以及近岸泥沙的输运特性,选取了ln z/h,ln c_(a),c_(a),u,ln u,z/h等6个变量作为自变量,采用多元线性回归的方法分析了6个自变量对泥沙浓度的影响。结果表明:参考点浓度对于泥沙浓度的影响最为显著,只采用相对水深计算出的泥沙浓度与实测值的相关性只有0.3左右;6个自变量中流速的敏感性(尤其是变量ln u)远低于参考点浓度,为非敏感因素;考虑5个主要自变量的方程计算的各点泥沙浓度与实测值的相关系数可达到0.8左右,表明采用的方法能够反映在复杂动力条件下近岸细颗粒泥沙浓度垂线分布的特征。

According to some the main assumptions in the Rouse equation,it the present study analyzes the applicability of Rouse distribution in the coastal region.Based on the classical Rouse equation,the linear form of Rouse equation and the transport characteristics of offshore sediment were used to take ln z/h,ln c_(a),c_(a),u,ln u and z/h as the independent variables.The multiple liner regression method was used to analyze the influence of the above independent variables on the vertical distribution of sediment concentration.By using the method of significance test,the factors(ln u)that have less influence on sediment concentration among 6 variables were eliminated.The correlation coefficient between the calculated sediment concentration and the measured sediment concentration indicates that the adopted variables can reflect the characteristics of vertical distribution of concentration of fine sediment near shore under complex dynamic conditions.