Analysis of the Temporal and Spatial Changes of Sea Level in Korean Coastal Zone

Abstract

In this study, the temporal and spatial changes of sea level in Korean coastal zone were analyzed. First, the error value of 1 hour tide data provided by the Korea Hydrographic and Oceanographic Agency was excluded through preprocessing, the analysis of sea level change was performed by considering long period components through low-pass filtering. Using low-pass filtering data, the monthly mean sea level was calculated and the temporal changes of sea level were verified by data fitting using linear fit and multidimensional smoothing spline. The results of linear fit show that the tide tends to rise at most stations. And the results of multidimensional smoothing spline fit show that the increase and decrease of sea level is repeated every year. Although the amounts of change vary every year, sea levels have been repeated seasonally, with sea levels rising in summer and falling in winter. Also, Hovmöller diagram was prepared for the change of sea level in each east, west, and south coast, and the temporal and spatial changes of sea level were analyzed. Compared to the past, recent sea level changes increased in all points. Especially, in the west coast, the sea level increased more in the south (Mokpo) area than in the north (Yeongjong Bridge), and the south (Mokpo) area of the west coast could be a vulnerable area due to the rise in sea level.