진양호 퇴적물의 이화학적 특성 변화

To investigate the change in physic-chemical characteristics in the sediments of the Jinyang lake, surface sediments were collected and analyzed for concentrations of organic matters (IL, TOC, and TN) and metals (Al, Zn, Cr, Pb, Cu, Ni, As, and Cd), and for grain size at three sites in four different years (from 2015 to 2018). Our results indicate that the water depth was shallowest at the HS3 site from the Namgang dam and highest at the adjacent site. Since an increased in 2016, concentrations of organic matters did not changed notably and they were lowest at the HS3 and highest at the HS2 and HS1 sites. Concentrations of most metals decreased after the increase in 2016 and were lowest at the HS3 site. Sediments were mainly composed silt and sand, while the sediments at the HS3 site had a coarser composition. Correlation analysis show that water depth affected grain size, which again greatly affected the concentration of organic matters and metals. Based on these results, we propose that the shallowest site in the study area was strongly affected by flow velocity, which resulted in a decrease in fine sediments and, consequently, in a relatively low pollution of organic matters and metals as compared to the deeper sites.