| Title |
A Study on the Water Quality Changes of TMDL Unit Watershed in Guem River Basin Using a Nonparametric Trend Analysis |
| Authors |
김은정 ( Eun Jung Kim ) ; 김용석 ( Yong Seok Kim ) ; 류덕희 ( Doug Hee Rhew ) ; 류지철 ( Ji Chul Ryu ) ; 박배경 ( Bae Kyung Park ) |
| DOI |
https://doi.org/10.15681/KSWE.2014.30.2.148 |
| Keywords |
Geum river; LOWESS; Nonparametric trend analysis; Seasonal Mann-Kendall test; TMDLs |
| Abstract |
In order to assess the effect of TMDLs management and improve that in the future, it is necessary to analyze long-term changes in water quality during management period. Therefore, long term trend analysis of BOD was performed on thirty monitoring stations in Geum River TMDL unit watersheds. Nonparametric trend analysis method was used for analysis as the water quality data are generally not in normal distribution. The monthly median values of BOD during 2004∼. 2010 were analyzed by Seasonal Mann-Kendall test and LOWESS(LOcally WEighted Scatter plot Smoother). And the effect of Total Maximum Daily Loads(TMDLs) management on water quality changes at each unit watershed was analyzed with the result of trend analysis. The Seasonal Mann-Kendall test results showed that BOD concentrations had the downward trend at 10 unit watersheds, upward trend at 4 unit watersheds and no significant trend at 16 unit watersheds. And the LOWESS analysis showed that BOD concentration began to decrease after mid-2009 at almost all of unit watersheds having no trend in implementation plan watershed. It was estimated that TMDLs improved water quality in Geum River water system and the improvement of water quality was made mainly in implementation plan unit watershed and tributaries. |