Study On The Influence Factors Of Erosion And Deposition Near The LiuGu River Estuary Area In Liaodong Bay

The Liugu River Estuary area is located in the west of Liaodong Bay, the coastline takes theshape of NE-SW. The area belongs to the accumulation of the plains of sandy coast, which isobvious for the erosion and deposition change.In recent years, the frequent human activities inLiaodong Bay, which greatly changed the water of the marine environment, affected the stabilityof the beach.In this paper, MIKE21numerical model is applied on the basis of the sediments, currents,suspended sediment,water depth,wave and satellite images, the flow field,wave field in LiaodongBay is established to carry out simulation on the characteristics of flow field before and after theconstruction and the characteristics of erosion and deposition features under various typical windconditions,and the use of satellite remote sensing images and changes in water depth ofgeomorphic scour evolution is verified.The CERC formula recommended in “Shore ProtectionManual”(SPM) of USA is applied to calculate the variation in long-shore sediment discharge ratein the study area,and furthermore the evolution of coastal topography and the influence factorswere also analyzed.The numerical model of flow field established in the paper proved consistently matched withactually-measured data.The ebb direction is from NE to SW in the study area.The flow rate ismaximum druing the moment between the high tide and the low tide, which is minimum whenthe high tide and the low tide.The wave field numerical simulation results show that themaximum wave height is4m, the shore wave height is smaller, approximately0.4m in the studyarea.The numerical simulation results of erosion and deposition shows that most area is deposition,the siltation rate is0.01~0.06m/a; the area of Liugu River Estuary and Diao Longzui iserosion,the erosion rate is0.02~0.1m/a.The longshore transport rate calculation results showsthat the migration of sand is from SW to NE.Through research, geomorphic effects of erosion and deposition in the region are: oceanichydrodynamic conditions, material sources and human activities. The main hydrodynamicfactors are tidal and wave-induced sediment transport. Tidal current affecting the transport ofsediments plays an important role through shaping the seafloor landforms. Wave, the mostimportant dynamic factors in the ocean, particularly nearshore waves, plays an important role onsediment movement. Considering the diameter flow, Liugu River, as one of the largest in the near area, has an considerable influence on estuarine delta, while is less important for much ofthe seafloor geomorphology. In addition, modern human activity is one of the main factorswhich causing coastal erosion, as well as scouring and silting variation on the seafloor. Coastaland offshore engineering construction and sea sand mining are common causes of direct humanactivities causing coastal erosion, while river sediment and sea surface elevation is also affectedby the indirect effects of human activities.