한반도 중부지역의 하천수질 통계 분석 = Statistical Analysis of the Stream Water Qualities in the Central Part of the Korean Peninsula

다국어 초록 (Multilingual Abstract)

Statistical analyses of water qualities were performed to compare the land use impacts on the receiving streams of the watersheds located in the central part of the Korean peninsula. The data were obtained from the three hundred seventy three tributaries in the watersheds including the Lower Han River, the South Branch of the Han River, the North Branch of the Han River, the Kyungan Stream, the Anseong Stream, the East Coastal Streams, and the West Coastal Streams. Triplicate samples were collected at each sampling station depending upon the flow conditions(mid, low, and high flow) from March to July 1992. The data were statistically analyzed by the multiple linear regression method, where explanatory and response variables were each land used types and receiving water qualities. The water quality parameters included in the statistical analyses were 5-day biochemical oxygen demand, suspended solids, anionic surfactants. and conductivity. The areal ratios of three different land use types were used as explanatory variables: urban area, agricultural area, and forest area. Regression coefficients were estimated for each water quality and the significances of coefficient values were tested using the t-test. Linear relationship between explanatory variables and response variable was also tested by the F-test. From this study, it was noted that receiving water qualities were significantly impacted by an urban area in all tested watersheds. The high values of regression coefficients were computed for the Lower Han River, the South Branch of the Han River, and the West Coastal Streams in the most water qualities. It was also recognized that urban area in the South Branch of the Han River and forest area in the West Coastal Streams shown unusual high values of regression coefficients in most water qualities. The result indicated that the regression method presented in this paper would be useful in comparing stream water qualities for multiple watersheds with multiple land use types.