Regional classification of total suspended matter in coastal areas of South Korea

Abstract

Total suspended matter (TSM) in coastal areas is affected by various sediment transport mechanisms. Thus, identifying systematically and robustly the regional pattern of TSM data is of great use for the management of coastal areas. The TSM sampling stations have been regionally clustered using an iterative toroidal SOM–k–means approach, which overcomes the cluster number determination and local optima problems. The iterative toroidal SOM–k–means is a two-step clustering approach that finds an optimal clustering result based on DBI by repeating the toroidal SOM and k-means clustering. Six variables (longitude, latitude, surface TSM in February and August, bottom TSM in February and August) were used as clustering variables, and cluster analyses were conducted while varying combinations of variables. All clustering results were analyzed using the sediment distribution, ocean currents, and tidal currents around South Korean coastal areas. Additionally, tidal flats around the Yeomha Channel, Hampyeong Bay, and Doam Bay, which are associated with sediment dispersion of turbid water, bay erosion, and tidal forcing, respectively, were identified during clustering analyses. This study's outcome provides the basis of regional sediment transport analysis in South Korea and an example of physical analysis based on the data-driven approach.