• Title/Summary/Keyword: Research Survey

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Impact of Baseflow on Fish Community in the Ungcheon Stream, Korea

  • Choi, Byungwoong;Oh, Woo Seok;Kim, Nam Shin;Cha, Jin Yeol;Lim, Chi Hong
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • v.2 no.4
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    • pp.235-246
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    • 2021
  • This study investigated the impact of baseflow on fish community in the Ungcheon stream (16.5 km long) located downstream of the Boryeong Dam, Korea. Based on field monitoring, there were five dominant fish species in the Ungcheon Stream accounting for 75% of the total fish community: Zacco platypus, Zacco koreanus, Tridentiger brevispinis, Rhinogobius brunneus, and Pungtungia herzi. These five fish species were selected as target species. HydroGeoSphere (HGS) and River2D models were used for hydrologic and hydraulic simulations, respectively. A habitat suitability index model was used to simulate fish habitat. To assess the impact of baseflow, each representative discharge was examined with or without baseflow. The HGS model was used to calculate baseflow within the study reach. This baseflow was observed to increase gradually with longitudinal distance. Validation of the hydraulic model dem onstrated that computed water surface elevated when baseflow was included, which was in good agreement with measured data, as opposed to the result when baseflow was excluded. Composite suitability index distributions and weighted usable area in the study reach were presented for target species. Simulations indicated that the baseflow significantly increased habitat suitability for the entire fish community. These results demonstrate that there should be a substantial focus on the baseflow for physical habitat simulation.

Case History for Safe Diagnosis of Embankment Dike using Composite Analysis of Various Geophysical surveys (물리탐사 결과 복합해석을 통한 방조제 제체 정밀안전진단 사례)

  • Song, Sung-Ho;Seong, Baek-Uk;Kim, Young-Gyu;Kang, Mi-Kyung;Lee, Gyu-Sang;Kim, Yang-Bin
    • 한국지구물리탐사학회:학술대회논문집
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    • 2007.06a
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    • pp.107-112
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    • 2007
  • To establish the reinforce region and technique through the embankment dike after identifying the region of seawater inflow, we carried out small-loop electromagnetic (EM) survey, electrical resistivity survey and refraction seismic method. We also analyzed the distribution of electrical conductivity in reservoir with depth every two month and monitored water level variations with tidal variation in four observation wells located at seaside and reservoir side in order to analyze the relationship with survey results. From both the cross-correlation between tidal and water level variation at four wells and the distribution of electrical conductivity in reservoir with depth, the major portion of seawater inflow are identified through the embankment dike. From electromagnetic and electrical resistivity survey results, it was found that the seawater inflow were happened through several small regions at seaside and became wider near reservoir side. The 2-D inversion sections of refraction seismic method showed that the pebble-bearing sand layer is spread over the whole region with two to four width. From the this study, small-loop EM, electrical resistivity and refraction seismic surveys accompany with the distribution of electrical conductivity in reservoir with depth and the monitoring results for water level variations are revealed to be effective to identify seawater inflow pathway through embankment dike and to establish the reinforce region and technique through the embankment dike.

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A Study on the Master Plan of Natural Environment Conservation compared with National Biological Survey in USA (환경부 전국자연환경조사사업의 문제점과 개선방안 - 미국의 사례를 중심으로 -)

  • Lee, Sang-Don
    • Journal of Environmental Impact Assessment
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    • v.12 no.1
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    • pp.1-8
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    • 2003
  • The Master Plan of Natural Environment Conservation in Korea by Ministry of Environment has been carried out since 1986. The 2nd 10-year survey started in 1997, and there are three major parts in the Master Plan : First, the basic natural environment survey, second, sites in special features of ecological characteristics such as uninhabitable islands, wetlands, etc, and third, biological species featuring status of habitat, and population dynamics. However the information in the Master Plan is very fragmented and collected data are not so abundant due to insufficient man-power and unsynchronized survey time/season. In this regard this paper examined the similar National Biological Survey in USA and compared the differences with the Master Plan in Korea. The Master Plan in Korea should separate the management zone based on hydrological characteristics, and in each zone we should set a management goal in the long term basis. Secondly the species list is not so meaningful that we must concentrate more on research activities. In each taxonomical group we set up hypotheses and research goals. Thirdly local residents and communities should be involved in research so that enhanced biological diversity should benefit people in areas. Lastly legislation and laws should be reexamined and rectified to provide information to the managers that deals with natural resources, expecially when conflicting with economic matters.

Development of a Groundwater Quality Sampling Method for Livestock Excreta Survey (가축분뇨실태조사를 위한 지하수 오염현황조사 지점 선정 방법 개발)

  • Kim, Deok-Woo;Ryu, Hong-Duck;Baek, Unil;Kim, Sunjung;Shin, Dong Seok;Lee, Jae Gwan;Chung, Eu Gene
    • Journal of Environmental Science International
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    • v.28 no.1
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    • pp.37-54
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    • 2019
  • The groundwater quality through livestock excreta survey based on "Act of the management and use of livestock excreta" was investigated by selecting sampling sites within 1 km of the farmland without considering hydrogeological units. However, these sites can be affected by various pollution sources such as chemical fertilizers and livestock excretions. Additionally, the effects of pollution sources on groundwater quality in the sites cannot be clearly distinguished from naturally occurring backgrounds. In this study, a method was developed to select the sampling sites for groundwater quality through livestock excreta survey in order to understand the effects of pollution sources especially livestock excreta. First, the concentrations of nitrate within the radius of 200 m, 300 m, 500 m and 750 m, respectively, from the farms regarded as pollution sources in hydrogeological units were compared in 2016-2017. All the nitrate concentrations at 200 - 500 m from the farms exceeded a background concentration, 13.3 mg/L. Those at 750 m and the background concentrations measured by the Ministry of Environment were comparable. Therefore, the appropriate radius was suggested as 500 m for livestock excretions survey. In this study, the areas within 500 m from the farms could be considered under the influence of livestock excretions, while those beyond 500 from the pollution sources as background in hydrogeological units. The developed method was validated by applying it to the sites selected based on both administrative divisions and watersheds for livestock excretion survey. The average densities for the developed method were 0.82 and 0.39 points/km2, respectively, which were considered as appropriate levels according to those of the European Environmental Agency.

Survey on the Occurrence of Apple Diseases in Korea from 1992 to 2000

  • Lee, Dong-Hyuk;Lee, Soon-Won;Choi, Kyung-Hee;Kim, Dong-A;Uhm, Jae-Youl
    • The Plant Pathology Journal
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    • v.22 no.4
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    • pp.375-380
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    • 2006
  • In the survey from 1992 to 2000, twenty-eight parasitic diseases were observed in major apple producing areas in Korea. The predominant apple diseases were white rot(Botryosphaeria dothidea), Marssonina blotch(Marssonina mali), Valsa canker(Valsa ceratosperma), Alternaria leaf spot(Alternaria mali), and bitter rot(Collectotrichum gloeosporioides and C. acutatum). Apple scab that reappeared in 1990 after disappearance for 15 years was disappeared again since 1997. A viroid disease(caused by apple scar skin viroid) was newly found in this survey. The five diseases, fire blight(Erwinia amylovora), black rot(Botryosphaeria obtusa), scab(Cladosporium carpophilum), Monochaetia twig blight(Monochaetia sp.), and brown leaf spot(Hendersonia mali), which had once described in 1928 but no further reports on their occurrence, were not found in this survey. However, blossom blight(Monilinia mali), brown rot(Monilinia fructigena), and pink rot(Trichothecium roseum), which did not occur on apple after mid 1970s, were found in this survey.

Effect analysis by time passage after Repair & Reinforcement of Fill Dams (필댐 보수보강후 시간경과에 따른 효과 분석)

  • Kim, Jae-Hong;Oh, Byung-Hyun;Im, En-sang;Hong, Won-Pho
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.697-703
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    • 2008
  • Excessive water leakage phenomenon happens through damage of nation core zone of about 17,000 storage of water facilities or collapse of dam is worried, is being damaged or enforce dilapidated fill dam core zone's repair reinforcement. Example that use grouting method of construction considering construction and economic performance etc. recently by repair reinforcement way about defect of dam is increased. Permeation grouting method repair & reinforcement of fill dam countermeasure is preferred in nation. Do that is economical to decide these repair reinforcement effect and grouting effect estimation method that do not give damage to dam is effective. Therefore, observing electricity resistivity Survey change of dam since grouting reinforcement using Electric resistivity Survey inquiry of seismic survey method in this research, Wished to verify grouting effect whether is possible as Electric resistivity Survey, and study whether integrity of dam through repair reinforcement defined.

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Demand Survey Method for Commercialization of Police Science Technology and Equipment

  • Myeonggi, Hong;Junho, Park;JeongHyeon, Chang;Seongju, Hong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.17 no.2
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    • pp.609-625
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    • 2023
  • This study is a demand research for the selection of public safety science and technology equipment and suggests an empirical research method. The technology demand survey is the beginning of the selection of innovative technology. And it is the basis of collecting information required for the technology required in the market and helping to apply it to the field. The demand survey for police science and technology can reduce the uncertainty of crime prevention and help the smooth implementation of security policies. However, in Korea, adoption of security science and technology equipment was centered on social issues or researchers' opinions rather than the demands of field users. Until, there was no research has been conducted on the demands of field police officers for selection of security science and technology equipment in Korea. Also, there was no preferential study for the demand for security science and technology equipment. Therefore, this study proposes a methodology that can systematically identify the needs for the technology and equipment of field experts suitable for the public security situation for the selection of security science and technology equipment. Specifically, we propose a sample design for a technology classification system and a survey tool for technology awareness and satisfaction. It is expected that this tool will provide a classification system for security science and technology equipment selected for the Korean police and will help determine the priority of equipment suitable for the field.