海口是沿海泻湖或海湾通向外海的口门。当这些泻湖及海湾有内河汇入时,从水动力学角度来衡量,与河口并无区别。海口的淡水迳流流量一般较小,泥沙来源主要是海沙。沉积性海岸的海口稳定性包括了断面和平面位置的稳定性。本文主要讲断面的稳定性。研究海口的稳定性则首先要研究海口潮汐水力学。 Haikou is the mouth of the sea lagoon or bay leading to the open sea. When these lagoons and gulfs have inland waterways, there is no difference from the estuary, measured hydrodynamically. Haikou’s freshwater raft traffic is generally small, the main source of sediment is the sea sand. The seaport stability of the sedimentary coast includes the stability of the cross-section and the plane position. This article focuses on the stability of the section. Studying the stability of Haikou is the first to study the tidal hydrodynamics of Haikou.