磨刀门河口在20世纪60至70年代的演变模拟与动力地貌过程分析

The evolution simulation and dynamic geomorphic process analysis of Modaomen Estuary from the 1960s to the 1970s

使用长周期动力地貌模型(long-term morphodynamic model),再现了磨刀门河口1964—1977年的演变过程,并从水动力、地形演变规律以及人类活动等角度系统分析了长周期地貌演变过程。模拟结果显示在1964—1977年磨刀门河口鹤州至交杯沙浅滩和上沟快速淤积,13a的平均淤积厚度均在40cm以上,与之相反,横洲水道杧州至大井角段和上沟东部深槽冲刷明显。磨刀门河口演变季节性特征明显。在洪季浅滩淤积,深槽冲刷;在枯季滩槽都处于淤积状态。演变过程中各种基岩岛屿使动力结构和演变规律呈现多元化,同时人类活动对整个区域的演变起到了重要的作用。

A long-term morphodynamic model is used to simulate the evolution course of the Modaomen Es-tuary between 1964 and 1977 ,by choosing representative condition.The results of the numerical simula-tion show that Hezhou to Jiaobeisha shallow bank and Shanggou have been fast -filling -up ,the deposi-tion thicknesses of the two areas both exceed 40 cm in 13 years. By contrast with the banks ,the Mangzhou to Dajingjiao part of Hengzhou Trough and the east-trough of “shanggou” are eroded and enlarged. The evolvement courses of the rainy season and dry season are ultimately different. In the rainy season ,banks are filled up and troughs are eroded ,but in the dry season banks and troughs are both filled up. In the process of evolution ,various rocky islands make the evolution course pluralistic ,and human activities have played import roles in the evolution of Modaomen estuary.