• Journal of Forest and Environmental Science
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• v.22 no.1
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• pp.41-49
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• 2006

The design instruction put in the wood structure construction manual of forest engineering works issued in Japan in 2004 is composed of the introduction, the use and characteristic of wood, investigation, planning, design, and etc. of wood structures. We analyzed the introduction, the use and characteristic of wood, investigation and planning for wood structures. By the results. the contents on the characteristic of wood are shown about physical and chemical properties of wood, the environmental influence, psychological and physiological effects, and rot of wood. The investigation items include the effective degree by flow and insolation, white ant's genital existence, flow conditions of surface water and ground water, situations of flora and fauna to live in mountain stream, the condition of water use, and etc. Also, the contents for the planning are explained for the structure, installation features. treatments, use of wood and lumber in the regions, preservative treatment, and etc.

• Journal of Korean Society on Water Environment
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• v.36 no.4
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• pp.275-283
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• 2020

Fecal coliforms are indicator bacteria to evaluate fecal contamination and microbiological safety in environment water. To examine fecal coliforms by membrane filtration, 1% rosolic acid solution dissolved in sodium hydroxide(0.2 M) should be added to m-FC medium according to Korean standard method. To reduce the exposure of researchers to harmful chemicals and expenditure of unnecessary cost, we evaluated if the rosolic acid solution is required to detect fecal coliforms. For 113 samples collected from five intake sources of Seoul, 42 samples of six tributaries, and 11 samples of sewage, the number of fecal coliforms was compared in medium with or without the reagent. As a result, the number was higher in m-FC medium without the reagent, but there was not a statistically significant difference. In the water intake, m-FC medium without the reagent could be used to examine fecal coliforms except in July, August and in case of rainfall. When heterotrophic plate counts exceeded 1,000 CFU/filter, or during rainfall, there was an effect of background bacteria in two types of the medium. However, it was more appropriate to use m-FC medium with the reagent to suppress gram-positive bacteria that can grow on medium without the reagent. In the tributary and sewage samples, the effect of the background bacteria was low, allowing the use of medium without the reagent regardless rainfall. Thus, it is necessary to present in standard method that the addition of rosolic acid solution in m-FC medium can be selected according to the characteristics of samples.

• Journal of Environmental Science International
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• v.10 no.3
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• pp.225-231
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• 2001

The fish species collected in the Keumho River basin are 42 species 31 genera belonging to 15 Families. This report was investigated for the evaluation of water quality in the Keumho River system which is a tributary of Nakdong River in Korea on september in 1999. The fishes collected were 42 species, 31 genera belonging to 15 Families. The dominant species were 5 species; Zacco platypus, Zacco temmincki, Squalidus chankaensis tsuchigae, Moroco oxycephalus, Squalidus gracilis majimae, and 8 species; Hemibarbus longirostris, Pseudogobio esocinus, Culter brevicauda, Cobitis rotundicaudata, Pseudobagrus fulvidraco, Pungitius sinensis kaibarae, Monopterus albus, Channa argus were rare species. The relationship among the GPI, EC and BOD by the organic pollutants were over 0.9. The group pollution index(GPI) was lowest at St. 1(0.85) and highest at St. 1(0.85) and highest at St. 5(2.33). The water quality of the Keumho river divided into 3 parts; the water of upper reaches in river(St. 1) was 1st class(oligotrophic condition), middle parts(St. 2, 3, 4) were 3rd class($\alpha$-mesosaprobic condition) and lower part(St. 5) was 4th class(Polysaprobic condition) as the source of tap water, respectively. And the tributary which are the Sinryeong Stream(St. 6), the Sincheon(St. 7) and the Donghwa Stream(St. 9) in Keumho river were 2nd class as the source of tap water. The results in this study was represented same patterns as the result by the use of indicator species like as algae and invertebrates for the discrimination of water quality. So, some freshwater fish species can be use applicant for the discrimination of water quality.

• Journal of Korean Society of Water and Wastewater
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• v.38 no.2
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• pp.69-81
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• 2024

In this study, an evaluation system that can be used to evaluate the feasibility of developing and supplying hydrothermal energy for the operation of large-scale complex facilities was developed. To this end, this study derived factors to be considered when selecting a location for the use of hydrothermal energy using raw water from multi-purpose dams and regional water supply systems through literature survey and expert interviews. The evaluation indicators derived from this study are divided into four sectors: hydrothermal energy utilization factors, location factors, planning factors, and disaster safety factors, and are composed of 10 mid-level indicators and 34 detailed planning indicators. The relative importance of all factors was derived using the Analytic Hierarchy Process (AHP) technique, and the developed evaluation indicators and relative importance were applied to four multi-purpose dam regions in the country. As a result, it was found that in the development and use of hydrothermal energy utilizing regional raw water supply line the urban planning conditions of the supply site can have a greater impact on the location selection results than the hydrothermal energy development itself. Due to the characteristics of the evaluation indicators developed in this study and their nature as comprehensive indicators, it is believed that the results should be applied to determine the overall adequacy of site selection in the early stages of hydrothermal energy development. In the future, it is believed that it will be necessary to analyze the problems in supplying and operating hydrothermal energy using raw water from multi-purpose dams and regional water resources. Based on the analysis the evaluation system developed in this study is expected to be improved and supplemented.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.697-701
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• 1996

King Sejong's Striking water-clock which brought in use on the first of July in 1434 was mainly composed of timekeeping and time announcing parts signalling twelve double-hours, and five night-watches and night-watch-divisions automatically by means of ball-operating jackworks. The clock was arranged with dual timekeeping system, the one for a full day(twelve double-hours) and the other for five night-watches achieving twelve double-hours and one-hundred interval horary systems. The vessels were arrayed in inflow-type water-clock, a large reservoir on the highest story, a constant-level tank for supplying water to the measuring vessel evenly in the middle, and the lowest tank to receive water from the above constant-level tank. An indicator-rod on the float was raised upwards depending on the water-level increase to show timing scales and also to release small bronze balls from the ball-rack mechanisms implanted on the measuring vessel to signal timing intervals.

• Journal of Korea Water Resources Association
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• v.39 no.12 s.173
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• pp.1067-1080
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• 2006

In empirical evaluations of public projects and public provided goods, MCDA(multicriteria decision-making analysis) has helped decision makers with an adequate policy decision-making tool since it allows taking into account a wide range of assessment criteria. As a tool for decision-making of conflict management, MCDA has demonstrated its usefulness in many public projects such as road, dam and harbor construction. In this study, to use this merit of MCDA, dam project assessment indicators from points of social, economic, environmental and practical views are developed based on sustainable development of water resources, and weighting factors are also estimated by means of questionnaire survey. In order to decide project investment rank, developed evaluation indicators are applied to 6 existing dams under investigation for a rehabilitation project. In addition to, it is recognized that the project practicability has become more important indicator as well as environmental and social issues. This is because cooperation and support from a local government and people are regarded as one of the most important problems in public projects recently.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.49-49
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• 2018

라오스의 Houay Pano 유역은 상업적 조림으로 인해 2011년부터 2013년까지 급속한 토지이용 변화를 겪어왔다. 본 연구는 이러한 토지이용변화가 박테리아 거동에 어떠한 영향을 주는지 이해하기 위해 Soil and Water Assessment Tool (SWAT) 모형을 활용한 박테리아 거동 모델링을 수행하였다. SWAT 모형은 수치 표고 모델, 토양 특성, 토지 이용 등의 정보를 종합하여, 유역 내수량 및 수질의 변화를 모의할 수 있는 모형으로, 본 연구는 대표적인 분원성 지표 세균 (Fecal Indicator Bacteria)인 대장균 (Escheichia coli, E. coli)을 대상으로 모델링을 수행하였다. SWAT 모형은 지표면 위 박테리아를 1)식물 위, 2)토양 용액상, 3)토양 입자상으로 구분하여 모의한다. 각 상태로 분할된 박테리아는 소멸 (die-off), 씻김 (wash-off), 침투, 표면 유출을 통한 수계로의 이동 등의 단계를 통하여 유역 내에서 거동한다. 본 연구는 서로 다른 기후의 영향을 배제하기 위해 각 토지이용 시나리오를 (2011, 2012, 2013) 실제 기후 조건과 동일 기후(2011-2013 평균) 조건으로 분류하여 분석하였다. 실제 기후 조건에서 SWAT 모형은 표면 유출, 토사 유출, E. coli 거동에 대해 2011년부터 2012년까지 감소, 2012년부터 2013년까지 증가로 모두 동일한 양상을 모의하였다. 이는 강수량의 양상과 동일한 것으로, 강수량이 표면 유출의 양을 결정하고, 달라진 표면 유출에 따라 토사 유출과 E. coli 거동이 결정되기 때문이다. 하지만 동일 기후 조건에서는, E. coli 거동 동인인 표면 유출과 토사 유출이 비교적 일정해짐에 따라, 각 상태로 분할된 박테리아의 초기 부하량값이 E. coli 거동을 결정하는 주된 요인임을 확인 할 수 있었다. 따라서 초기 부하량 분할에 활용되는 엽면적 지수 (Leaf Area Index)와 분배계수 (BACTKDDB)의 정확도가 요구된다. 추가적으로 본 연구는 박테리아의 유입원인 비료 모델링과, LAI를 활용한 박테리아 초기 부하량 산정, 토양 특성 변수와 토지 이용 변수의 분리, 지하수를 통한 박테리아 거동 등을 중심으로 SWAT 모형의 한계점과 개선점을 제시하였으며, 본 연구 결과는 토지이용변화가 박테리아 거동에 주는 영향을 모형적으로 이해하고, 또한 추후 박테리아 모델링 개발에 도움을 줄 것으로 예상된다.

• Ocean and Polar Research
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• v.43 no.2
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• pp.65-72
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• 2021

In order to evaluate the dissolved organic carbon (DOC) and fluorescent dissolved organic matter (FDOM), as indicators of organic matter in the coastal environments, we measured the concentrations of DOC, FDOM, and chemical oxygen demand (COD) in saline groundwater (Woljeong, Pyoseon, and Hwasun beaches) and coastal seawater (Haengwon, Gwideok, Pyoseon, and Yeongnak) in Jeju, Korea. The highest concentrations of DOC and COD in groundwater were found in Woljeong and Pyoseon, and those in coastal water were observed in Haengwon and Pyoseon, indicating that the higher concentrations of DOC and COD seem to be associated with saline groundwater-driven dissolved organic matter (DOM) and/or biogeochemical processes. According to origin and optical properties of DOM using FDOM as a tracer, proportion of humic-like FDOM, more refractory DOM, was relatively greater in the groundwater than in the coastal water. With regard to this result, there was no relationship between DOC and COD in groundwater, while DOC showed a good positive correlation (r² = 0.66) with COD in coastal water. This result indicates that COD as an indicator of assessment of DOM has a limitation in which it is difficult to quantify refractory DOM. Although DOC is a potential alternative to COD in the coastal environments, particulate organic carbon cannot be negligible due to relatively higher concentration compared to the open ocean. Therefore, the use of total organic carbon (TOC) as a replacement of COD in the coastal ocean is important, and the evaluation criterion of the TOC is necessary in order to evaluate of organic matter indicator in the various coastal environments.

• Journal of Environmental Health Sciences
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• v.26 no.4
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• pp.45-48
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• 2000

Reverse osmosis filtration(RO) system and ultrafiltration(UF) system are principally use for domestic home drinking water treatment systems. The object of this study is to make a comparison between two systems in terms of theirs abilities to remove RNA coilphage QB as an indicator of pathogenic enteroviruses. The virus removal ratio of RO system was 99.999%, which was higher than EPA virus treatment guideline(99.99%). In the course of filtration, removal ratios of sediment filter, pre-carbon filter, reverse osmosis membrane and post-carbon filter were 75.000%, 93.208%, 99.997% and 99.999%, repectively. In case of UF system, virus removal ratio was 99.708%. Removal ratios of sediment filter, pre-carbon filter, post-carbon filter and ultrafiltration membration membrane were 71.038%, 91.530%, 98.283% and 99.708%, respecively, in UF steps. Therefore, RO system is more effective than UF system in virus removal.

• Membrane and Water Treatment
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• v.10 no.1
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• pp.29-38
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• 2019

Microbial community and composition in stormwater runoff from mixed land use land cover (LULC) catchment with ongoing land development was diverse across the hydrological stage due different environmental parameters (hydrometeorological and physicochemical) and source of runoff. However, limited studies have been made for bacterial composition in this catchment. Therefore, this study aims to: (1) quantify the concentration of fecal indicator bacteria (FIB), stormwater quality and bacterial composition and structure according to hydrological stage; and (2) determine their correlation to environmental parameters. The 454 pyrosequencing was used to determine the bacterial community and composition; while Pearson's correlation was used to determine the correlation among parameters-FIB, stormwater quality, bacterial composition and structure-to environmental parameters. Results demonstrated that the initial and peak runoff has the highest concentration of FIB, stormwater quality and bacterial composition and structure. Proteobacteria, Bacteroidetes, Actinobacteria and Firmicutes were dominant bacteria identified in this catchment. Furthermore, the 20 most abundant genera were correlated with runoff duration, average rainfall intensity, runoff volume, runoff flow, temperature, pH, organic matter, nutrients, TSS and turbidity. An increase of FIB and stormwater quality concentration, diversity and richness of bacterial composition and structure in this study was possibly due to leakage from septic tanks, cesspools and latrines; feces of domestic and wild animals; and runoff from forest, destroyed septic system in land development site and urban LULC. Overall, this study will provide an evidence of hydrological stage impacts on the runoff microbiome environment and public health perspective.