基于指数收敛的喇叭形河口河宽公式研究及应用

Research and application of river width formula in exponential convergent funnel-shaped estuaries

基于卫星遥感影像,提取了我国6个喇叭形河口沿程河宽数据,采用LANZONI和SEMINARA提出的喇叭形河口河宽收敛公式进行拟合,得到的河口形态与实际形态偏差较大,从而对公式参数进行优化,提出基于河口上下游宽度比和水域面积的两个河宽收敛公式。研究表明:提出的公式对喇叭形河口平面形态拟合相关系数更高。引入收敛误差和喇叭形态参数作为喇叭形河口及其收敛性的判别指标。以椒江河口为原型建立概化喇叭形河口水动力模型,得到基于新提出公式模型的水动力特征更接近实际河口。

Based on satellite remote sensing images,the river widths along six funnel-shaped estuaries in China were extracted,and the convergence formula proposed by Lanzoni and Seminara in 1998 was used for fitting.It was found that the fitted estuary shapes deviated significantly from the actual ones.In order to improve accuracy,two new formulas concerning the ratio of mouth width to upstream width and water area were proposed by optimizing the parameters of the formula.Results show that for the 6 funnel-shaped estuaries in China,the two new proposed formulas have better R-squares compared with Lanzoni and Seminara′s formula.Furthermore,the convergence error is used as an identification index for the funnel-shaped estuaries and the funnel-shape parameter is proposed to represent the convergence of the estuaries.In order to check the applicability of the two convergence formulas in models,the hydrodynamic simulation based on the Jiaojiang Estuary as a prototype using three fomulas were conducted,suggesting that the hydrodynamic characteristics for the newly proposed formula models are closer to the actual estuaries.