Abstract:

The sea reclamation plays an important role in relieving contradiction between human and lands, increasing food security, expanding development space and promoting economic development in the coastal areas. It was necessary to research on the restriction line of sea reclamation, exploring the suitable sea reclamation scale and development intensity which would comply with the natural evolution tendency and accommodate to the bearing capacity of marine resources and environment. Through the sustainable utilization of the marine spatial resources expected to be realized, 〖JP2〗the restriction line of sea reclamation was the biggest outer enveloping curve on the basis of feasible engineering project, which would not change the ocean dynamic pattern and natural evolution tendency. On the foundation of the characteristics analysis of open coast and the impact on resources and environment of sea reclamation, the controlling factors had been identified from marine environment factors, including important environment sensitive objectives, marine resources and marine hydrodynamic conditions. According to analysis of the interaction mechanism in different controlling factors, the sea reclamation controlling index could be designed and the method of determining the threshold of sea reclamation controlling index had been put forward. In order to analyze different reclamation scheme’s influence on marine geodynamic pattern evolution, the iterative optimization model of sea reclamation restriction line was constructed. The iterative optimization algorithm was put forward by using hierarchical filtering and iterative approximation method. Besides, the tidal current numerical simulation and sediment siltation prediction technique were applied in the iterative optimization model. Taking Yaosha (peninsular shoal in the radial sand ridge of Jiangsu Province) as an example, the sea reclamation scale evaluation was carried out. Distinguishing the sea reclamation controlling factors by analyzing the natural resources and social and economic conditions, the iterative optimization model of sea reclamation restriction line had been constructed. And the Yaosha twodimension tidal current mathematical model and sediment empirical model were used to analyze different sea reclamation restriction line scheme’s influence on the tidal current field and accretionerosion environment in the adjacent sea area. Especial attention had to be paid to the impact on tide flow and flow field characteristics of tidal channel such as Xiaomiaohong, Sanshahong and Wangcanghong, et al. The calculation results showed that the reclamation restriction line was 2.8 m above the theoretical datum plane in Yaosha. The research method and iterative optimization model could not only provide methodology and reference for other coastal provinces, but also provide scientific basis for formulating the total amount control indicators of sea reclamation scale