A Long-Term Monitoring of Major Hydrovariables and its Spatiotemporal Variabilities - A Study from the Korean Riverine Systems

A Long-Term Monitoring of Major Hydrovariables and its Spatiotemporal Variabilities

  1984년부터 1993년까지 한강 및 낙동강 수계의 수질자료에 대한 분석을 지역적 및 시간적 배경을 중심으로 실시하였다. 월별 및 계절별 분석에 의하면, 온도, 유속, 용존산소량 등의 변수는 수계에 상관없이 규칙적인 분포양상을 띄었다. 그러나 더 장기적인 주기로 분석하였을 때는 수계에 따라 훨씬 다양한 결과를 보여 주었다. 한강지역의 경우, TN과 TP가 규칙적인 변화를 보인데 반해, 낙동강지역은 시간의 경과와 함께 농도의 지속적인 증가경향을 보여주었다. 두 수계에 대해 상하류를 중심으로 상관성을 분석한 결과는 낙동강 지역에서 강한 상관성이 존재한다는 것을 확인할 수 있었다. 낙동강에서 측정한 수질변수들이 높은 상관성을 보이는 것은 호수와 같은 낙동강의 지형적 특성에 의한 것으로 사료된다. 이와 같은 수질변수의 분포경향 및 상관성 분석을 통해 이들 지역의 수질분포는 대단히 복잡한 요소들에 의해 조절된다는 것을 입증할 수 있었다.

  To investigate both short- and long-term distribution characteristics of several major water-quality variables, we conducted a series of statistical analyses on the data sets collected from both up- and downstream stations of the Han (HR) and Nak Dong River (NOR) over a ten year period (1984 through 1993). A comparison of the data over different time scale revealed several important aspects of their temporal distribution characteristics. The analysis of monthly, or seasonal, trends indicated that variables like temperature, flow rate, and DO display most periodically reproducible patterns, regardless of geographical locations. The analysis of long-term distribution trends of those variables indicated quite contrasting features between the two rivers: TN and TP levels of the HR did not show any systematic patterns over time, while their counterparts for the NOR exhibited a consistently increasing pattern over the study periods. When the data for each river were analyzed between up- and downstream waters, correlations were found more abundantly from the NOR than from the HR. The observations of enhanced spatial homogeneity in the former is likely to come from the shallow, lake-like geographical characteristics of the Nak Dong River. Results of our correlation analyses also indicated the possibility that some biochemical (e.g., DO, COD, and SS) and physical parameters (temperature, flow rate) may be affected in similar manners. Such relationships were most frequently seen from the downstream waters of the HR due probably to effective mixing of water in that area. The overall results of our study on the water-quality conditions in the two major riverine systems show that their distributions are controlled by the mixed effects of various physicochemical properties.