• Economic and Environmental Geology
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• v.52 no.1
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• pp.91-106
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• 2019

The Donghachong tomb from Royal Tombs at Neungsanri is composed of 15 sides including the floor, and the most highly proportion of rock, two-mica granite, are used on the 7 sides (46.6%). Also, augen gneiss consist with another 3 sides (20.0%), and each of the remaining 3 sides (6.7%) are made up of granodiorite, gneissous granite and leucocratic granite, all of which were used to comprise the tabural stone. Meanwhile, the two floors of the burial chamber and the front chamber, are made up of brick-shaped amphibole schist (13.3%). These rocks are occurred in the Buyeo area and their provenance sites are located at the side of Guemgang river. The Memorial Stone for Liu Renyuen in Tang China is a typical augen gneiss showing distinct schistosity and augen texture. This rock has the same petrographic characteristics with the rocks used to build the Donghachong tomb, Sanjikri dolmens and Setapri pagoda in Buyeo. This augen gneiss is distributed from the Jeungsanri in Buyeo to Dukjiri in Gongju as a large scaled rock body, and where currently are the quarries to produce stone aggregates, garden and landscape rocks. Thus, it is highly probable that the site around Buyeo was the source area of augen gneisses since the Bronze Age. However, while augen gneiss is easier to form into shapes it should have disadvantages when it comes to painting on the tomb wall because of their petrographic characteristics of low strength and dark color. Therefore, it is very intriguing to investigate which transportation method the people of Baekje chose with consideration of the distance and terrain, efficiency and convenience.

• Journal of Wetlands Research
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• v.20 no.4
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• pp.314-321
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• 2018

In order to quantify nonpoint source pollution, it was proposed to sample at regular intervals of 1 hour for the first 24 hours of storm runoff process by National Institute of Environmental Research for the mixed landuse watershed. However, high frequency sampling requires intensive laboratory analysis and labor costs. In order to investigate the effect of longer sampling interval on the load estimation compared to the 1 hour sampling method, analysis was conducted using monitoring data from rural subwatershed, urban subwatershed, and outlet of the Pungyeongjeongcheon watershed. Statistical analysis revealed that mean of load estimation was not significantly different up to 4 hour sampling frequency. However, 3 hour sampling interval was found to be appropriate for the BOD and TP when it is judged that 10% or less of the difference in loading amount between the 1 hour and other sampling interval is reasonable. The results of this study can be used to conduct an effective monitoring system.

• Journal of Environmental Impact Assessment
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• v.28 no.2
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• pp.129-140
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• 2019

Majangcheon is a small agricultural stream which is located in Chuncheon-si, Gangwon-do. To understand ecological characteristics of Majangcheon as biological habitats, we surveyed its physical environment and fishes from June 2016 to September 2016. The altitudinal difference between lowest and highest point of the stream was 3 meters and the first-order stream under a map drawn on a scale of 1:25,000. The flow rate of stream was slow in overall with $0.09-0.48m{\cdot}s^{-1}$. More than 50% of clay were found in all points except for the point St. 3 in the riverbed structure surveyed. A total of 2,532 individuals of 22 species in nine families were collected from Majangcheon. Of them, stillwater-living species (Acheilognathinae and Carassius auratus) and floating species (Zacco platypus and Oryzias sinensis) were mainly collected. In Majangcheon, thus, both of stillwater-living and floating fishes were specifically coexisted. The correspondence analysis, based on fishes collected from Majangcheon and past research, showed that Majangcheon is closer to the flat streams in Gyeonggi-do rather than the mountainous streams in Gangwon-do but it appeared as an independent group from those of two regions. As a result, Majangcheon is a stream with specificity of fish community.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.17 no.2
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• pp.245-261
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• 2019

Radioactive contaminant from a nuclear facility moves to the ecosystem by run-off or groundwater flow. Among the two mechanisms, contaminant plume through a river can be easily detected through a surface water monitoring system, but radioactive contaminant transport in groundwater is difficult to monitor because of lack of information on flow path. To understand the contaminant flow in groundwater, understanding of the geo-environment is needed. We suggest a method to decide on monitoring location and points around an imaginary nuclear facility by using the results of site characterization in the study area. To decide the location of a monitoring well, groundwater flow modeling around the study area was conducted. The results show that, taking account of groundwater flow direction, the monitoring well should be located at the downstream area. Also, monitoring sections in the monitoring well were selected, points at which groundwater moves fast through the flow path. The method suggested in the study will be widely used to detect potential groundwater contamination in the field of oil storage caverns, pollution by agricultural use, as well as nuclear use facilities including nuclear power plants.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.21 no.6
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• pp.55-69
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• 2018

As disaster risk and climate change volatility increase, there are more efforts to adapt to disasters such as forest fires, floods, and landslides. Most of the research, however, is about influence of human activities on disaster and there is few research on disaster adaptation for species. Previous studies focusing on biodiversity in selecting conservation areas have not addressed threats of disaster in the habitats for species. The natural disasters sometimes play role of drivers of ecological successions in the long run, but they might cause serious problems for the conservation of vulnerable species which are endangered. The purpose of this study is to determine whether soil loss (SL) is effective in selecting habitat management areas for amphibians and reptiles. RUSLE model was used to calculate soil loss (SL) and the distribution of each species (SD) was computed with MaxEnt model to find out the biodiversity index. In order to select the habitat management area, we estimated the different results depending if value of soil loss was applied or not by using MARXAN, a conservation priority selection tool. With using MARXAN, conservation goals can be achieved according to the scenario objectives, and the study has been made to meet the minimum habitat area. Finally, the results are expressed in two; 1) the result of soil loss and biodiversity with MATRIX method and 2) the result of regional difference calculated with MARXAN conservation prioritization considering soil loss. The first result indicates that the area with high soil loss and low species diversity have lower conservation values and thus can be managed as natural disturbances. In the area where soil loss is high and species diversity is also high, it becomes where a disaster mitigation action should be taken for the species. According to the conservation priorities of the second result, higher effectiveness of conservation was obtained with fewer area when it considered SL in addition to SD, compared to when considered only biodiversity. When the SL was not taken into consideration, forest area with high distribution of species were important, but when SL considered, the agricultural area or downstream of the river were represented to be a major part of habitats. If more species data or disaster parameters other than soil loss are added as variables later, it could contribute as a reference material for decision-making to achieve various purposes.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.245-245
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• 2017

하천 시설물은 홍수시 혹은 비상시 운영할 수 있는 경보시스템이나 관리지침 등의 마련이 필수적임에도 불구하고, 현재까지 가동보 시설물에 대한 비상시 운영 메뉴얼 및 경보시스템이 구축되지 못한 실정이다. 4대강 살리기 사업이나 하천정비사업과 같은 대표적인 하천관련 사업에서 단순한 하천 이 치수 목적뿐만 아니라 소수력 발전, 친수공간조성 등의 다목적 활용을 위하여 가동보 설치 사업이 다수 수행되었으며, 현재 국내 하천에 약 1,200여개의 가동보가 설치 운영되고 있다. 이와 같이 다목적 활용을 위하여 가동보의 수요가 급증하는데 반해, 각 설치 현장 상황에 적합한 가동보 운영지침이나 비상경보시스템이 구축되지 못한 실정이며, 적절한 지침 없이 관행적인 가동보 방류로 인한 물놀이 안전사고나 인명피해가 속출하고 있는 실정이다. 2012년 11월에는 하천 제수변 공사를 위해 전주천에 설치한 가동보를 임시적으로 방류하였는데, 하류측의 안전을 확인하지 않고 관행적으로 가동보를 방류하였고, 경보시스템의 부재로 인하여 가동보 하류측 징검다리를 건너는 유치원생들이 급류에 휩쓸리는 사고가 발생하였고, 최근 2014년 5월에는 수원시에 위치한 원천저수지 여수로 둑에 설치된 가로 34m 높이 1.6m 크기의 가동보가 공기압축기의 오작동으로 인하여 보 높이가 낮아지면서 약 30분 원천저수지 하류의 원천리천에 갑자기 무리 불어나 산책로가 침수되고 인근에 산책하던 주민들이 휩쓸려 떠내려가는 사고가 발생하였다. 해외에서도 가동보 운영 미숙으로 인하여 인명사고가 발생하는데, 2008년 11월 호주에서는 하류측 상황 점검이나 경고 방송 없이 가동보를 도복시켜 4살 여아가 급류에 사망하는 사고가 발생하였다. 국외의 경우에는, 상류측 홍수 수위나 하류측 역류 수위를 조절하기 위하여 가동보의 높이를 제어하는 시스템을 구비하고 있지만 이러한 시스템 역시 단순한 수위조절 기능으로서 가동보의 방류량을 제어하지 못하는 실정이다. 가동보를 운영하기 위한 조작시스템은 국내의 경우, 조작실의 조작판넬을 이용하여 가동보의 기립/도복 조작이나 원격 조작 기능과 같은 단순기능만을 구비하고 있어 가동보 방류시 하류측의 범람 피해를 야기하고 있다. 본 연구에서는 가동보 방류에 의한 하류측 범람 피해를 최소화하기 위하여 (1)가동보 도복에 의한 방류량 산정 알고리즘을 개발하고, (2) 방류량에 따른 하류측 수위상승 범위 예측 기법을 개발하고, (3) 가동보 도복 속도를 제어하는 방류량 제어시스템을 개발하고, (4) 가동보 방류에 의한 비상경보시스템을 개발하였다.

• (The)Study of the Eastern Classic
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• no.73
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• pp.91-117
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• 2018

In the tribute system controlling international relations of pre-modern East Asia, conciliation diplomacy between royal authorities was a principle of diplomatic relations among each nation. Therefore, capitals where royal authorities really existed were political centers and diplomatic stages at the same time. Notably, diplomatic relations between United Silla and Japan were maintained dually by conciliation diplomacy between royal authorities and practical diplomacy through Dazaihu located in Tsukushi. Tsukushi located at the northwestern tip of Kyushu was a gateway to foreign nations and stronghold in terms of national defense. Amidst an East Asian war named Baek River Battle in 663, the royal court of Daehwa established Dazaihu here because it was necessary for diplomatic and military responses. Dazaihu established as part of diplomatic negotiation not only took diplomatic functions as an official residence since the latter half of the 7thcentury. and but also was used as a stage of official diplomacy between Silla and Japan. Diplomatic negotiation between Silla and Japan through Dazaihu was made in practical methods and such a situation could be confirmed through diplomatic documents exchanged between Silla and Dazaihu in the middle of the 8thcentury. At that time, protocols became an importan tissue.

• Journal of Korea Water Resources Association
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• v.55 no.6
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• pp.405-419
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• 2022

Flood frequency analysis commonly used to design the hydraulic structures to minimize flood damage includes uncertainty. Therefore, the most appropriate design flood within a uncertainty should be selected in the final stage of a hydraulic structure, but related studies were rarely carried out. The total expected cost function introduced into the flood frequency analysis is a new approach for determining the optimal design flood. This procedure has been used as UNCODE (UNcertainty COmpliant DEsign), but the application has not yet been introduced in South Korea. This study introduced the mathematical procedure of UNCODE and calculated the optimal design flood using the annual maximum inflow of hydroelectric dams located in the Bukhan River system and results were compared with that of the existing flood frequency. The parameter uncertainty was considered in the total expected cost function using the Gumbel and the GEV distribution, and the Metropolis-Hastings algorithm was used to sample the parameters. In this study, cost function and damage function were assumed to be a first-order linear function. It was found that the medians of the optimal design flood for 4 Hydroelectric dams, 2 probability distributions, and 2 return periods were calculated to be somewhat larger than the design flood by the existing flood frequency analysis. In the future, it is needed to develop the practical approximated procedure to UNCODE.

• Economic and Environmental Geology
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• v.55 no.5
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• pp.447-463
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• 2022

The lime and clay that used in the construction of the Tomb of King Muryeong and the Royal Tombs in Gongju are auxiliary materials, and are used joint and plaster materials for the wall to play a role of structural support. In this study, the homogeneity between the tombs and material characteristics were interpreted through quantitative analysis of lime and clay. As a result of microtexture and composition analysis, almost the same minerals were identified in each sample groups, and similar characteristics were shown in thermal analysis. Geochemically, it is confirmed that the behavior characteristics are very similar regardless of the tombs. The compositions is also confirmed high homogeneity in the diagrams of CaO-MgO-SiO₂, RO₂-(RO+R₂O) correlations, A-CN-K and A-CNK-FM triangles. Therefore, it is interpreted that the clay used for the construction of the tomb complex was supplied from around area, and the raw materials of lime were produced using shell fragments of oyster family based on mainly composed of calcite. It is interpreted that the raw materials of lime were supplied from middens along the west coast of down the Geumgang river in Korean peninsula, but the consideration of the supply site, needs to be cross-validated through stable isotope analysis, use of carbonate rock and reproduction experiments.

• Journal of Wetlands Research
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• v.24 no.3
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• pp.155-160
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• 2022

The debate of South-North transboundary rivers must be expanded from the existing cooperation in water resources towards cooperation within ecosystem conservation. Regarding the Han and Imjin rivers confluence water system, the nature of the estuarine ecosystem must be conserved considering the aspect of climate change. Furthermore, the agenda of maintaining continuous inter-Korean communication and cooperation should focus on ecosystem conservation, including conserving migratory species that inhabit both Koreas. Notably, within the Han and Imjin rivers confluence, transboundary rivers are abundant legally protected species such as Grus vipio, Anser fabalis, Anser cygnoides, Platalea minor, Lutra lutra, Prionailurus bengalensis which suggests a strong need for a debate regarding habitat conservation. This study analyzed the ecosystem conditions and environmental aspects within the confluence of Han and Imjin rivers. In addition, this study provided step wise approach of ecosystem conservation that consider conditions for potential direct inter-Korean cooperation. The inter-Korean cooperation mentioned in this study will be developed into legitimate cooperation once the results from monitoring the ecosystem of transboundary rivers, awareness raising are exchanged.