珠江虎门口动力结构研究

Dynamic Structure of Humen Estuary of the Pearl River

虎门口是珠江八大入海河口之一,其形成是上游河流携带泥沙在两基岩岛侧淤积延伸的结果,属潮汐优势型河口。口门上、下游方向水面放宽,形成了独特的双向不对称射流体系,通道口以北为涨潮优势流,通道口以下南为落潮优势流;基于几个重要的河口参数和滤波技术,从双向射流,密度环流及其对沉积物输运等方面分析了虎门口的动力结构特点:虎门动力环境中,非线性作用和摩擦力的影响均不能忽略,在密度梯度力驱动下,枯季发育了密度环流,这从浅表层沉积物的输运和低频水流的输运上得到了验证,同时,密度环流与双向射流相互交汇,更增加了射流系统的复杂性。

The Humen Estuary is a tidal-dominant estuary, which is aggrad rock by deposition of sediment in river. With broadened water surface in the ed and stretched at both sides of bedlower and upriver part of the gate, and under control of the morphology, particular bidirectional asymmetric jet system was formed. Flood tide flow is dominant in the north of the channel while ebb tide flow is dominant in the south. Based on some important estuarine parameters and filter technic, the dynamic structure characteristics of the Humen Estuary such as vertical density circulation and sediment transportation are analysed in the paper. Effect of nonlinear process and friction should not be neglected in the dynamic environment of the Humen estuary. There is density circulation in dry season, which responds with transport of sediment in the surface layer and low-frequency current. On the other hand, convergence of density circulation and bidirectional jet make jet systems in the Humen more complex.