Study On The Stability Of Beach In The South Bank Of Taozi Ba

Eighty percent of the sandy beaches in Shandong Province have been eroded.The eroded beaches are characterized by coarsening of sediment,narrowing of width,increasing of slope and retreating of shoreline.A large amount of sediment is missing near the coast,which damages the original ecological environment and restricts the development of coastal beach tourism.Taozi Bay is located in the north of Yantai,and its south beach is the key tourist beach of Yantai,which is also the main research object of this paper.This paper mainly studies the stability of the beach in the south of Taozi Bay,in order to provide a scientific theoretical basis for the development and management of Yantai coastal beach.The main works of this paper are as follows: 1)due to the lack of measured hydrodynamic data in Taozi Bay,a one-year hydrodynamic numerical simulation of Taozi Bay is carried out,and the simulation results of tide,current and wave are analyzed;2)the field investigation of the beach on the South Bank of Taozi Bay is carried out for more than one year(beach profile measurement and sediment sampling),and indoor analysis is carried out based on the analysis and treatment,the evolution of the beach is studied;3)combined with the beach evolution and hydrodynamic data,the main factors affecting the stability of the beach are analyzed.The conclusion is as follows:(1)Through the analysis of the field measured data and surface sand sample data of the beach,it is found that the annual change of the overall amount of erosion and deposition of the beach is small,the monthly change of the profile obviously oscillates around the zero line,and the particle size of the whole beach is relatively concentrated,and no drastic change of the particle size is found,which indicates that the beach on the South Bank of Taozi Bay is relatively stable in this year.(2)There is a correlation between the beach erosion and the seasonal variation of waves.In spring and winter,the waves are mostly northward,and the average effective wave height is larger,and the beach is eroded;in autumn,the waves are mostly eastward and northward,and the average effective wave height is smaller,and the beach is silted;in summer,the waves are mostly southward,and the amount of erosion and deposition is much smaller than the other three quarters.(3)The shoreline of the beach on the South Bank of Taozi Bay is predicted by using Mepbay software.It is found that the predicted shoreline and the observed shoreline almost coincide,which indicates that the shoreline of the South Bank of Taozi Bay is basically in a stable state under the influence of long-term wave action.(4)Typhoon has a significant effect on beach stability.Typhoon "lekima" caused the increase of hydrodynamic intensity in the Bay,which caused the widespread typhoon erosion on the beach in the South Bank of Taozi Bay.After the typhoon,the beach changed relatively slowly,and the sediment deposited in the Bay moved towards the shore under the action of waves,resulting in the deposition of the beach.Affected by the typhoon,the sediment in the Bay increased,resulting in the deposition of the beach far greater than the erosion.