EVOLUTION CHARACTERISTICS OF WEIFANG ARTIFICIAL BEACH AND THE EOF ANALYSIS ON PROFILE CHANGE

We made a study of the measured beach profiles in the Weifang artificial beach after the second stage of the nourishment project.Empirical Orthogonal Function(EOF) is applied to analyze the spatial and temporal features of the beach profiles and the evolutionary features of the beach from May 2013 to November 2015.The results indicate that the beach profile evolution includes 3 phases.The first phase represents the overall change of the beach,and the erosion is significantly decreased compared with the first-stage project after the establishment of the groins on both east and west sides and a new T-type groin in the middle of the beach;The second phase represents the inter-conversion between the beach ridge and the beach bar in the foreshore area affected by topography and hydrodynamic interaction;the third phase represents the accidental disturbance of storm surges and human factor.The plane view of the beach shows that erosion is more serious in the central and eastern parts than in the west part of the artificial beach.The purpose of beach optimization is achieved after the second-stage of the project.It is necessary to monitor the beach regularly to understand more for future construction and maintenance of the artificial beach.