瓯江河口江心屿汊道分流特性研究

Characteristics of Flow Division in Jiangxinyu Anabranched Channel of Oujiang Estuary

汊道分流特性分析是汊道演变研究的基本问题之一。历史上瓯江河口江心屿汊道分流比变化大致可划分为剧变期、缓变期和稳定期3个阶段。结合瓯江河口近期河床演变的特点,对江心屿河段节点控制断面的分布进行分析,提出汊道分流比的简化计算方法,并与现场实测数据进行对比和研究。结果表明,该简化计算方法具有较高的效率和精度;江心屿汊道河段受自然山体地质构造和人工涉水建筑物的影响,汊道分流比受南北2汊节点断面过水面积比的影响显著。

Characteristic analysis of flow division is one of the elementary problems in studying the fluvial processes of anabranched channel in a macro-tidal estuary. Historical changes of flow division ratio in Jiangxinyu anabranched channel of Oujiang estuary can be roughly divided into three stages,including upheaval,gradient and stationary phases. According to the recent characteristics of fluvial processes in Oujiang estuary,the distributions of control section as channel node around Jiangxinyu Island are analyzed in this paper,and a simplified calculation method is proposed to determine the flow division ratio of the anabranched channel. It is shown that the proposed method has the advantage of high calculation efficiency and accuracy. Jiangxinyu anabranched channel is deeply affected by geological structures of natural mountain and waterway contractions of artificial buildings. The results of parameter analysis show that flow division ratio is mainly controlled by the discharge section area ratio of control section in two branch nodes.