• Water for future
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• v.2 no.2
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• pp.42-51
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• 1969

• Journal of Microbiology and Biotechnology
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• v.18 no.6
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• pp.1156-1163
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• 2008

We performed RT-nested PCR to study the distribution of human enteric viruses in urban rivers in Korea. During 2002-2003, water samples were collected from four rivers in Gyeonggi Province, South Korea. Among 58 samples, 45 (77.6%), 32 (55.2%), 12 (20.7%), 2 (3.4%), 4 (6.9%), and 4 (6.9%) showed positive results with adenoviruses (AdVs), enteroviruses (EVs), reoviruses (ReVs), hepatitis A viruses (HAVs), rotaviruses (RoVs), and sapoviruses (SVs), respectively. According to the binary logistic regression model, the occurrence of each enteric virus, except ReVs and HAVs, was not statistically correlated with the water temperature and levels of fecal coliforms (P<0.05). AdVs were most often detected; only 4 samples (6.9%) were negative for AdVs while positive for other enteric viruses in the studied sites. Our results indicated that monitoring human enteric viruses is necessary to improve microbial quality, and that AdVs detection by PCR can be a useful index for the presence of other enteric viruses in aquatic environments.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.5 no.3
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• pp.13-20
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• 1985

An initial attempt to investigate the forced fortnightly water-level modulations in major tidal rivers in South Korea is described. Simplified one-dimensional hydrodynamic numerical models were established to reproduce the fortnightly tides in the Keum River and the Nakdong River respectively. The models were also used to identify the approximate locations of the reversal of MLWS and MLWN in the Keum River and the Nakdong River. The basic features of this forced fortnightly waves are explained through scaling arguments proposed by LeBlond. The objective of this initial study is to investigate the tidal dynamics of the major tidal rivers in South Korea.

• Journal of Ecology and Environment
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• v.36 no.1
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• pp.85-88
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• 2013

Bioassessment is the use of biosurvey data, most commonly for benthic macroinvertebrates and fish, to obtain information about the health of waters in a region. In rivers, bioassessment results are used to evaluate biological condition and trends, to establish relationships between stressors and impairments, and to guide and evaluate management actions.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.9 no.3
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• pp.209-213
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• 1976

Spinous loaches widely distributed in Korea, are of many color pattern types, but interestingly the crossband B and C-types of these coaches are collected only in the two rivers, the Yeongsan River and the Seomjin River, flowing through the south-western part of Korea. These two types have not only different color pattern, but also different geographical distribution: the B-type is found in the Yeongsan River and the C-typs, in the Seomjin River. But the both types have four common distinctive features, which easily distinguish them from other already known species of this genus: the B and C-types have the similar total length distribution, the same structure of lamina circularis and scales, and the black spots at the back of their opercula. These peculiarities may be explained by studing the history of these two rivers. The author considers that they are once rivers of the same origin located around the Noryeong and the Sobaeg Mountains, and then were eventually separated from each other as the water level or the crust of Korea peninsula changed. Thus, these two types, B and C, of spinous loaches should have been the same species living in the same river, but in the course of time, these two types have taken different color patterns since the separation of two rivers thus making them impossible to cross between these two populations.

• The Korean Journal of Pesticide Science
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• v.15 no.1
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• pp.48-54
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• 2011

Risk assessments of pesticides detected in six major rivers during peak season were estimated for algae, Daphnia, and fish using hazard quotient (HQ) indexes. The eight pesticides (isoprothiolane, hexaconazole, diazinon, chlorpyrifos, prothiofos, alachlor, butachlor, molinate) were detected within the range of 0.027~12.871 ${\mu}g/L$. Detection frequency of isoprothiolate was estimated to be high at 67.5%, and those of the others varied from 15.0 to 37.5%, Hazard Quotients (HQ) indexes varied by freshwater organisms (algae, Daphnia, and fish). Overall, the ecological risk probability due to exposure of pesticides detected in major rivers did not reveal based on HQ indexes below 1.0. Particularly, butachlor and molinate for algae, chlorpyrifos, diazinon, prothiofos for Daphnia, and chlorpyrifos for fish acted as dominant contributors in increasing the ecological risk in six major rivers. This implied that integrated ecological risk assessment is required using various biological species, reflecting toxicity sensitivity. This study may provide the essential data in establishing the priority for pesticides management in major rivers, Korea.

• Journal of Korea Water Resources Association
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• v.57 no.4
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• pp.301-310
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• 2024

The spatial and temporal non-uniform distribution of precipitation makes water management difficult. Due to climate change, nonuniform distribution of precipitation is worsening, and droughts and floods are occurring frequently. Additionally, the intensity of droughts and floods is intensifying, making existing water management systems difficult. From June 2022 to June 2023, most of the water storage rates of major dams in the Yeongsan river and Seomjin river basin were below 30%. In the case of Juam dam, which is the most dependent on water use in the basin, the water storage rate fell to 20.3%, the lowest ever. Pyeongnim dam recorded the lowest water storage rate of 27.3% on May 4, 2023. Due to a lack of precipitation starting in the spring of 2022, Pyeongnim dam was placed at a drought concern level on June 19, 2022, and entered the severe drought level on August 21. Pyeongrim dam and Suyangje(dam) have different operating institutions. Nevertheless, the low water level was not reached at Pyeongnim dam through organic linkage operation in a drought situation. Pyeongnim dam was able to stably supply water to 63,000 people in three counties. In order to maximize the use of limited water resources, we must review ways to move water smoothly between basins and water sources, and prepare for water shortages caused by climate change by establishing a consumer-centered water supply system.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.2190-2199
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• 2009

Nihombashi is located in the central area of Tokyo, Japan. Tokyo has been the capital in Japan since the Edo period, which started approximately 400 years ago, and has accepted a variety of cultures, human resources, businesses for the last 400 years. This has resulted in building up the present prosperity. The Sumida River, one of the symbols of Tokyo and its tributaries including the Kanda River and the Nihombashi River, flows through the Nihombashi district. The river and tributaries used to benefit to the City of Edo. Due to the economic development and the industrial growth in Tokyo, however, they were polluted and lost their functions. In 1960s, approximately 40 years ago, the Sumida River became so dirty that local citizens kept away from it. The Nihombashi River was covered with an expressway, which was obscuring the river view. Since 1970s, local communities have proposed to rehabilitate rivers in Tokyo successively, and have proceeded with measures for river floods, improvement of sewage systems and construction of water purification facilities. Consequently, the quality of the river water was considerably improved in 1990. The stagnant rivers were turned into ones that local citizens were physically able to come close by. Today, restoring of the environment and the appearance of the city in the old days, Nihombashi district has been proposed as a model city of the future, which is alive with history and culture and harmonizing with rivers. The concept is "To Create, To Reserve, To Restore." This paper introduces a case study of the urban development, in which the local communities and public authorities collaborated with and proposed a brand-new style of the urban city harmonizing with the environment.

• Journal of Korea Water Resources Association
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• v.37 no.11
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• pp.889-896
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• 2004

The fractal advection-diffusion equation (ADE) is a generalization of the classical AdE in which the second-order derivative is replaced with a fractal order derivative. While the fractal ADE have been analyzed with a stochastic process In the Fourier and Laplace space so far, in this study a fractal ADE for describing solute transport in rivers is derived with a finite difference scheme in the real space. This derivation with a finite difference scheme gives the hint how the fractal derivative order and fractal diffusion coefficient can be estimated physically In contrast to the classical ADE, the fractal ADE is expected to be able to provide solutions that resemble the highly skewed and heavy-tailed time-concentration distribution curves of contaminant plumes observed in rivers.

• Environmental Engineering Research
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• v.15 no.3
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• pp.173-179
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• 2010

Pasig River is an important river in the Metro Manila, Philippines, since it provides food, livelihood and transport to its residents, and connects two major water bodies; Laguna de Bay and Manila Bay. However, it is now considered to be the toilet bowl of Metro Manila due to the large amount of wastes dumped into the river. Even with the efforts of the government to revive the quality of the Pasig River and its tributaries, it continues to deteriorate over time. This paper provides an overview of the current condition of the Pasig River. The existing water management policies were reviewed, and the issues and challenges hindering the improvement of its water quality identified. Moreover, the water qualities of the rivers in Metro Manila were compared to those of the major rivers in South Korea. The current watershed management system practiced by South Korea has been discussed to serve as a guideline for future recovery of the water quality of the rivers in the Philippines.