In order to evaluate hydrodynamic condition changes of large-scale reclamation in Xuanmen Bay, two models of big and small domain are respectively developed to calculate M2 tidal component with 2-D nonlinear tidal wave equations. The distributions of the cotidal lines and isoamplitude lines of M2 are given. Comparing phases and amplitudes of post-reclamation with ones of pre-reclamation, changes of velocity and direction of tidal wave propagation are obtained. The results show that the hydrodynamic condition change in the sea area around embankment is distinct, while in other area it is slight.
In coastal areas of Southeast China, with the rapid development of the economy, there are more and more types of beach development, and the scale of reclamation is increasing. The reclamation will change the shoreline, and have certain effect to the movement of current, wave and sediment. Especially, the large-scale reclamation project might result in sediment deposition, environmental deterioration, ecological changes, etc. All of these problems are caused by the changes of the hydrodynamic conditions. Most of the methods, which assess the influence of reclamation on the hydrodynamic field, are to calculate the changes of tidal level and current velocity at sampling points and to estimate the changes of tidal prism at partial regions, and so on. In this paper, changes of tidal waves are studied from a macroscopic perspective instead of general act. Xuanmen Bay (Fig. 1)(refer to the full paper) lies in Zhejiang Province, southeast of China, at 28°8′N, 121°18′E. The length of the bay in the west-eastward direction is 7.3 km and that in the south-northward direction 9.3 km. The reclamation project consists of one primary dike and two affiliated dikes, with the total length of 5.3 km, which basically make the whole bay closed. The area of tidal flat reclamation can reach to 44.8 km2 after the project completion, which is one of the largest scale reclamation projects in China.
