하계 강우기 전,후 신구저수지 내 입자성유기물의 수직분포 및 기원 연구 -탄소 및 질소 안정동위원소비의 활용-

Abstract

A Study on Vertical Distribution and Oriin of Particulate Organic Matter in Shingu Reservoir in Pre-monsoon and Post-monsoon Period -Application。f Carbon and Nitrogen Stable Is ­tope Ratio-. Kim, Min-Seob, Yeonjung Lee, Kyung-Hoon Shin* and Soon-Jin Hwang1 (De­ partment of Environmental Marine Science, Hanyang University, Ansan 425-791, Korea; 1Department of Environmental Science, Konkuk University, Seoul 143-701, Korea) The vertical distribution and origin of particulate organic matter (POM) were inve­ stigated in Shingu reservoir on 4th July (pre-monsoon) and 7th August (post-mon­ soon) 2006. High turbid water (120 NTU) were found at 4.5 m water depth in post­ monsoon period. The average C/N ratio of POM was about 5.70 and 6.96 in surface water and bottom water, respectively in pre-monsoon period, exhibiting the close values to its ratio in phytoplankton cell. However, the average C/N ratio was 7.10 in surface water and 12.81 in bottom water in post-monsoon period. In addition, the 13C values of POM in pre-monsoon period ranged from -25.1%0 to -26.1%0 in whole water column, but the a13C values of POM in post-monsoon period showed relatively wide range between -23.2%0 and -27.5%0. The apparently lighter values (average- 27.5%0) in near bottom water (4.5 m water depth) demonstrate that POM in high turbid water in post-monsoon period may be derived from the outside terrestrial plants through heavy rainfall during the summer monsoon period. The present study suggests that carbon and nitrogen stable isotope ratios as well as C/N ratios should be useful indexes to clarify the origin of POM.