• Journal of Korean Society on Water Environment
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• v.35 no.4
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• pp.352-361
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• 2019

The purpose of this study is to analyze the characteristics and correlations of the Yeongcheon Lake in order to reduce the occurrence of harmful cyanobacteria. In this study, we investigated the water quality and phytoplankton of the lake from May to November in 2017. Correlation and data mining analyses were performed to analyze the relationship between the two factors. The water temperature was lowest at the point where the Yeongcheon Lake inflow occurs at Imha Lake. It was highest at the point where the outflow occurs to Angye Lake. The pH was also highest at the outflow point, but in the case of DO, it was highest at the midpoint between the inflow and outflow. The main cyanobacteria that emerged during the study period were Oscillatorialimosa, Microcysti saeruginosa and Aphanizomenon flos-aquae. As a result of correlation analysis, the water temperature, inflow, COD loading, TOC loading at the inflow point of the Yeongcheon Lake were the items that were related to the harmful cyanobacteria. The data mining analysis indicated that the TP loading and harmful cyanobacteria in the inflow point of the Yeongcheon Lake were influential on the detrimental cyanobacteria in the Yeongcheon Lake outflow point. When the TP loading was less than 39.0 kg/day at the inflow site, it was expected that the amount of harmful cyanobacteria could be maintained below 10,000 cells/mL.

• The Korean Journal of Quaternary Research
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• v.19 no.1
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• pp.41-46
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• 2005

This study discusses the soil erosion on hillslopes and sediment deposition in lakes within catchments in South Korea. In order to determine seasonal variations of sedimentation in Yeongcheon and Seondong lakes, the sediment traps were set in the deep part of both lakes and lake sediments have been sampledmonthly from July 2004 to August 2005. Some properties such as highmineral content, fine particle size and high particle density in the Yeongcheon Lake indicate intensive soil erosion, sediment transportation and deposition throughout the catchment for a long time. The high sediment yield in the Seondong Lake is related with higher weathering intensity and extreme soil erosion by running water due to higher seasonal rainfall amount. Rates of erosion and sedimentation in the Seondong Lake are estimated to be higher than those of the Yeongcheon Lake, suggesting that the Seondong Lake is associated with higher precipitation, smaller catchment area, and extreme soil vulnerability to ephemeral erosion by overland flow during the heavy rainfall event. Consequently, both catchments are characterized by different erosion and sedimentation processes, as well as different geomorphic factors (bedrock, soil structure, rainfall intensity and catchment area).

• Korean Journal of Ecology and Environment
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• v.42 no.3
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• pp.331-339
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• 2009

This study evaluated the potential human health risk on the basis of the level of bioaccumulation and EDI (Estimated Daily Intake) of microcystin-LR, one of hepatotoxic, in organs, including liver, muscle, viscera and gill, of fish from Lake Yeongeheon and Lake Daecheong when the cyanobacterial water-blooms broke out. The result has confirmed that Carassius cuvieri from Lake Yeongcheon contains higher level of microcystin-LR in its organs including liver. In Lake Daecheong, omnivorous Hemibarbus labeo and phytoplanktivorous Carassius cuvieri have shown high microcystin-LR level on average, especially higher for viscera, and Carassius cuvieri has appeared to contain higher level of microcystin-LR in the liver and the gill compared with other species. As a result of comparison between EDI of microcystin-LR from each organs and TDI (Tolerable Daily Intake) of WHO (Chorus and Bartram, 1999) to evaluate human health risk, the EDI levels from Carassius cuvieri's organs except museles have exceeded TDI level at the both lakes. Consequently, the study has proved that microcystin was bioaccumulated in the various parts of fish, and it can be ingested by human resulting in risking human health. Continuous monitoring and reducing consumption of fish, especially Carassius cuvieri, during the cyanobacterial water-blooming period will be needed to protect human health.