• 한국환경과학회지
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• 제29권5호
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• pp.531-539
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• 2020

To understand the composition, quantity, and quality of Suspended Particulate Organic Matter (SPOM) in the Gangneung Namdae Stream, Korea, we examined spatiotemporal variations in water temperature, salinity, chlorophlly a (Chl a), Particulate Organic Carbon (POC) and nitrogen (PON), and carbon stable isotope (δ¹³C) of SPOM at six stations in June (pre-monsoon), July (monsoon), and September (post-monsoon) 2017. With increasing precipitation, the average POC and C/N values increased significantly in July than in June. In September, the values decreased with decreasing precipitation. The δ¹³C values showed irregular spatiotemporal fluctuations among the stations and periods, thereby suggesting a greater contribution of autochthonous organic matter to the pool of SPOM than that of allochthonous organic matter derived from upstream. In addition, the large and irregular changes in POC, C/N ratio, C:Chl a, and δ¹³C compared to that of PON were observed for all periods among the stations, indicating a serial discontinuity of the stream. Our results suggest that the Gangneung Namdae Stream is significantly influenced by the increase in freshwater discharge caused by heavy rainfalls during the summer monsoon and post-monsoon periods.

• 한국환경과학회지
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• 제31권10호
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• pp.861-868
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• 2022

The Namdae stream in Gangneung-si is one of the rivers where salmon stock is mainly maintained by natural spawning rather than artificial seedlings. There are structures including weir, and fish distribution and movement characteristics can be different by these structures. In this study, we investigated the distribution and behavioral characteristics of salmon by sighting survey within 12 km immediately upstream of the river mouth between October 2021 and February 2022. As a result, salmon distributed within 9 km from rivermouth. There were more salmon in the lower reaches of Doosan weir than in the upper reaches of that. The main spawning ground for salmon was between 7-9 km from rivermouth and around the lower part of Doosan weir. Salmon behaved for spawning in the gravel-bed area and undercut slope of the mainstream, such as mating, digging the riverbed, and competition among males. Salmon moved more slowly in the gravel-bed area than sand-bed area. Doosan weir hinders the spawning migration of salmon by frequent flow changes and terraced fishway. This study provides primary information to understand the ecological changes of salmon by environmental changes in the Namdae stream.

• 한국해양환경ㆍ에너지학회지
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• 제6권1호
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• pp.68-77
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• 2003

강원도 강릉시에 위치하지만 성격이 서로 상이한 남대천과 연곡천 하구와 연안역에서 발생하고 있는 오염현상의 원인을 규명하기 위하여 하천의 수질과 동해 연안으로 방류되는 오염물질의 량을 2002년 4월부터 11월까지 월 1회씩 7회에 걸쳐 조사하였다 남대천은 하천수질 기준 II-V 등급으로 변화가 큰 반면, 연곡천은 거의 I, II 등급 수질을 유지하고 있다. 상ㆍ하류간 변화는 물론 시기별 변화폭도 연곡천보다 남대천이 크다. 동해연안으로 배출되는 오염물질의 량도 유량이 평균 1.4배 정도 많고 오염물질의 농도도 더 높은 남대천이 연곡천보다 BOD는 15.5배, COD는 2.6배, 총질소는 1.7배, 총인은 6.9배 더 많이 배출시키고 있어 연안생태계에 미치는 영향도 클 것으로 사료된다.