Relationship between Water Quality Parameters and Socio-economic Factors of 34 Semi-closed Coasts, Korea ; 반폐쇄성 해역의 수질환경과 사회경제활동의 상관성에 관한 연구

This study reports the relationship between the water quality parameters and the natural and socio-economic activities in the semi-closed coastal areas. Study areas were selected by connecting between cape points through the analysis of bathymetric charts. Watershed areas adjacent target semi-closed seas were defined based on topographic maps. Variables representing geographical characteristics of the watersheds include surface area, perimeter, elevation, slope, longest axis, and diagonal axis, which are estimated by the analysis of Digital Elevation Model (i.e., DEM) data. Socio-economic characteristics of the watersheds are represented by four population variables, 12 livestock-related variables, three industrial activity variables, eight land use variables, 21 pollutant discharge load variables, and 8 sewage treatment facilities variables, which were selected from national statistics survey in 2006. Parameters of the water quality including annual average of 13 measured items (temperature, salinity, DO, COD, NO2, DIN, DIP, TP, Si, SS, Chlo-a, etc.) were obtained from Korean marine environmental monitoring system. All statistical analyses were conducted by using SAS (version 9.2). Factor analysis for each parameter or variable group results in the selection of key explanatory variables in the group, which are later used for analyzing relationship between variables and the effect of variables on the water quality. DO, COD, DIN and Si was selected for representing the water quality parameters in 34 semi-closed coasts. COD concentration was chosen as a representative variable, since factor analysis shows that phosphorus, one of major nutrients, can have similar impact as COD. Total nitrogen and nitrite are regarded as same factor as DIN. In addition, variables representing natural and socioeconomic activities are as follows: watershed area and elevation from watershed geographical variables, cross-sectional area and mean tidal range from marine geographical variables, rural population and population density from ...