Study On The Hydrodynamic Environment And The Erosion And Deposition Environment Of The Sand Beach Regulation Projects In The South Area Of Weihai Bay

The Sand Beach Regulation Projects locate on Yanjia Bay of the south area of Weihai Bay. Obstructed from the bulkhead wall of west, the hydrodynamic condition and the ability of water exchange is poor. Because of the injection of wastewater along the Changfeng River, the estuarine water is turbidity and smelly. The beach of Yanjia Bay is ever on the static equilibrium, it changed with some area of the coast and the sand beach eroded because of the appearance of some coastal projects. The sand beach regulation projects will be built in order to change the hydrodynamic condition of the estuarine of Changfeng River, avoid the beach erosion in the area and promote the formation of the sand beach between the estuarine of Changfeng River and Jiulong River.The ECOMSED model is used to simulate the hydrodynamic environment and the erosion and deposition environment of Weihai Bay, the result is accord with the actual conditions. Then the present hydrodynamic environment and erosion and deposition environment of the study area is simulated. The result is also accord with the actual conditions. Then the hydrodynamic environment and erosion and deposition environment of the beach with the projects is forecasted. It is showed that the hydrodynamic environment and erosion and deposition environment are improved. But there are a banding erosion area between the estuary of Changfeng River and Jiulong River and is possible to form a gully in the area. And there are 3 banding erosion areas with a deep erosion in study area on the climate of strong wind from NW. So the effect is not well.In this paper the static equilibrium theory of headland-bay is used to estimate the stability of the coast with the sand beach regulation projects by the area constitute of the projects and coast regarded as headland-bay. It is showed that there is a erosion area between the estuary of Changfeng River and Jiulong River which is corresponding to the position of the erosion area of the simulation result. The coast with the optimized projects which optimized by using the static equilibrium theory of headland-bay will abstractly be static equilibrium.Then the hydrodynamic environment and the erosion and deposition environment of the beach with the optimized projects are simulated. It is showed that the hydrodynamic environment and the erosion and deposition environment are obviously improved. The beach with optimized projects is in state of slight erosion which is beneficial to form the sand beach and hold the stability. The effect with optimized projects is well. But it is possible to form a obvious erosion area with deep erosion. It is suggested that some protective measures should be built to avoid the further erosion of this area and hold the stability of the coast.