Depositional environment classification based on environmental variables of South Korea's Nakdong River Estuary barrier-lagoon system.

Anthropogenic activities have altered the geomorphological and ecological conditions of the Nakdong River Estuary (NRE) dramatically over the last century. The objectives of this study were to classify NRE sub-environments and to identify their unique ecological functions. The first step in classification was the establishment of 14 a priori sub-environmental groups based on landscape factors. Surface sediments obtained for these groups were analyzed for factors related to grain size and organic matter. Based on the results, the NRE was divided into two primary estuarine environment divisions: (1) a mixed marine and terrestrial environment influenced primarily by land; and (2) a principally marine environment influenced primarily by the ocean. Using multivariate analysis, we subdivided these primary estuarine divisions into six sub-environments, including Sub-1 and -2 in the former and Sub-3, -4, -5, and -6 in the latter.