| Title |
Trend Analysis for River Water Quality Change Before and After the Prohibition of Ocean Dumping of Livestock Manure |
| Authors |
최현미 ( Hyeon-mi Choi ) ; 조용철 ( Yong-chul Cho ) ; 이보미 ( Bomi Lee ) ; 류인구 ( In-gu Ryu ) ; 김상훈 ( Sang-hun Kim ) ; 신동석 ( Dongseok Shin ) ; 유순주 ( Soonju Yu ) |
| DOI |
https://doi.org/10.15681/KSWE.2021.37.2.75 |
| Keywords |
Bukhan river; Imjin river; Livestock manure; Ocean dumping ban; Trend analysis |
| Abstract |
Ocean dumping manure was prohibited in Korea until the end of 2012. Undumped manure was treated by resourcification, purification, and public process in a facility. But poor storage of untreated manure and overproduced compost can pollute river water. In this study, linear regression, Mann-Kendall, Seasonal Mann-Kendall, LOWESS trend, and Spearman’s correlation analysis were conducted for investigating the changes in the water quality of Bukhan and Imjin river before and after the prohibition of ocean dumping. In 2017, the Imjin River basin had more than 5 .7 times livestock breeding heads than the Bukhan River basin and more than 3.5 times livestock manure. The areas of land, farmland, and nutrient balance were also higher in the Imjin River basin. Since the two basins have different environments, it is expected that the characteristics of changes in water quality due to the increase in livestock manure generation and treatment methods will be different when comparing the water quality trends before and after the ban. The result of the trend analysis revealed a decrease in EC before the ban but an increase afterward. T-N and BOD of Imjin river increased slightly before the ban but demonstrated great enhancement thereafter. Other sites and T-P exhibited no trend. The correlation analysis result showed that the increase in the number of livestock rearing was correlated with the increase in T-P of Bukhan River and BOD of Imjin River. The increase in livestock manure production was not correlated with the Imjin River basin, while a correlation was observed with the Bukhan River with an increase in T-N and EC and the decrease in T-P. |