• Journal of Korean Society on Water Environment
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• v.32 no.4
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• pp.349-356
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• 2016

Total Maximum Daily Loads (TMDLs) System has been used to improve water quality in the Youngsan·Tamjin river basin since 2004. The Basic Policy of TMDLs sets up the standard flow based on the average dry condition or mid-range flow during the last 10 years. However, Target Water Quality (TWQ) assessment on TMDLs has been used to evaluate water quality through eight-day intervals over 36 times a year. The results for allocation evaluation and target water quality evaluation were different from each other in the same unit watershed during the first period. In order to improve the evaluation method, researchers applied Load Duration Curve (LDC) to evaluate water quality in nine unit watersheds of the Youngsan·Tamjin river basin. The results showed that achievement rates of TWQ assessment with the current method and LDC were 67~100% and 78~100%, respectively. Approximately 11% of the achievement rates with use of LDC were higher than those with use of the current method. In conclusion, it is necessary to review the application of the LDC method in all Four Major River Watersheds.

• Journal of Korea Water Resources Association
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• v.48 no.8
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• pp.647-657
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• 2015

This study assessed the water use vulnerability for 12 basins of South Korea. The annual runoff of 12 basins are derived using a Soil and Water Assessment Tool (SWAT) and the calculated runoff per unit area and population are compared with each basin. The 18 indicators are selected in order to assess the vulnerability. Those are classified by aspects of demand, loss and supply of water use. Their weighting values used Entropy method to determine objective weights. To quantitatively assess the water use vulnerability, the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) based on multi-criteria decision making are applied. The results show that the water availability vulnerability of Hyeongsan River has the highest value followed by Sapgyo River; Dongjin River; Seomjin River; Anseong River; Mangyung River; Nakdong River; Tamjin River; Youngsan River, Geum River; Taehwa River; and Han River. The result of this study has a capability to provide references for the index deveopment of climate change vulnerability assessment.

• Parasites, Hosts and Diseases
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• v.27 no.1
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• pp.41-46
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• 1989

This study was performed to observe the infection rate and infection intensity of fresh water fish such as pale chub (Z. platypus) and dark chub (Z. temminckii) with the metacercariae of C. armatus. The fish were caught in several rivers and streams from June to September, 1988 and examined by artificial digestion technique. Total 370 fish were caught at 19 rivers. The metacercarial (C. armatus) infection rate and average burden in Z. Platypus were 86.8% and 224, and those in Z. tsmminckii were 78.5% and 131. The infection rate and burden per fish were 73.4% and 32 in the fish caught from the Han river, and 88.0% and 44 from the Youngsan river. All fish caught from the Keum and the Tamjin river were infected and their mean metacercarial density was 45 and 59 respectively. The infection rate and density in fish caught from the Seomjin and Nagdong rivers were 100% and 119, and 81.0% and 348 respectively. From this study, it is confirmed that C. armatus is widely distributed along 5 major rivers in Korea.