节点和岩岛对河口分汊的影响

本文主要论述作为先成边界条件的节点(包括矶)和岩岛对河口分汊的影响.指出节点和矶的分布和性质对河口能否形成分汊以及分汊形态等具有不容忽视的作用。表明单个节点易形成喇叭状的少汊河口,多个节点则易导致藕节状展宽及分汊河口,而节点位于口门,则不利于河口展宽而使得河口难以分汊。在研究河口岩岛对河口分汊的作用时,分别从珠江口、韩江口和闽江口三个分汊河口,分析了岩岛的数目多少、规模大小和分布状况,对导致河口形成不同分汊模式的影响。

Effects of rocky nodes and islands on estuarine branching

on the basis of analysing the branching estuaries in China, this paper points out the influence of rocky nodes and islands in estuarine area on the estuarine branchified process. The boundary conditions can be divided into two cases: one boundary condition has been formed earlier than the estuary was formed. In this case estuary hsa been influenced by this condition throughout the estuarine process. The other boundary condition was formed later than the estuary was formed. Banks are accumulated by the river sediments, and influenced by the estuarine processes to a certain extent. The number, scale and distribution of the rocky nodes and islands in an estuary can control the branching models of estuaries. This paper also studies quantitatively the influence of distance between two nodes or islands, on the estuarine branchified models. With a rocky node situated on the entrance of the estuary, the estuary tend no easy to be widened and branchified. Finally, in accordance with some examples in Chinese estuaries, the paper gives out four models of the rocky nodes and islands in branching estuaries.