Conditional correlation between beach width and wave data on the east coast of south korea

Abstract

We investigated correlations between shoreline change and ocean waves observed along the east coast of South Korea by analyzing the relationship between beach width acquired from video monitoring data on five sandy beaches and wave data from three nearby monitoring points. Although the correlation coefficient estimated over for the full data set was not particularly high, the correlations estimated under some wave conditions provided more specific information. When wave heights were above a certain level (the non-exceedance probability of the wave height reaching ~0.99), the wave period and beach width showed a strongly negative correlation. When wave periods were above a certain level (the non-exceedance probability of the wave period reaching ~0.99), the wave height and beach width also showed a strongly negative correlation. Thus, it is necessary to analyze the wave height and period when assessing changes in beach width in order to acquire more relevant and useful information. Furthermore, the beach erosion rate (based on width) increased when the coastline was nearly perpendicular to the primary wave direction.