• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2003년도 The Fifth Asian Computational Fluid Dynamics Conference
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• pp.211-212
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• 2003

Three dimensional flow above a sand dune has been studied numerically by using Large-Eddy Simulation (LES) method. The movement of the sand which is formed by converging wind directions has been investigated. The numerical method employed in this study can be divided into three parts: (i) calculation of the air flow above the sand dune using MAC method with a generalized coordinate system; (ii) estimation of the sand transfer caused by the flow through the friction; (iii) determination of the shape of the sand surface. Since the computational area has been changed due to step (iii), (i)­(iii) are repeated. The simulated dune, which has initially elliptic cross section, extending at the converging direction which is known as linear dunes.

• Geomechanics and Engineering
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• 제2권3호
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• pp.213-227
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• 2010

Compacted layers of sand-bentonite mixtures have been proposed and used in a variety of geotechnical projects as engineered barriers for the enhancement of impervious landfill liners, cores of zoned earth dams and radioactive waste repository systems. This paper presents a study on the valorization of local materiel such as dune sand from Laghouat region and mine bentonite intended for the realization of liner base layers in the conception of insulation barriers for hazardous waste centers. In the practice we try to get an economical mixture that satisfies the hydraulic and mechanical properties specified by regulation rules. The effect of the bentonite additions on the mixture is reflected by its capability of clogging the matrix pores upon swelling. In order to get an adequate dune sand-bentonite mixture, an investigation on hydraulic and mechanical behaviours is carried out in this study for different mixtures. Using oedometer test, the adequate bentonite addition to the mixture, which satisfies the conditions on permeability, is found to be around 12% to 15%. These results are also confirmed by direct measurement using triaxial cell.

• 한국지형학회지
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• 제26권3호
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• pp.31-42
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• 2019

The geomorphological changes of an unvegetated part of the Okjukdong coastal dune were analyzed between 2008 and 2018. Its natural landscape has been destroyed after artificial forestation, but there is no quantitative evidence on these changes. In this study, we measured the unvegetated area using a total station and a network RTK-GPS in 2008, 2014, and 2018. Using Krging method for the three point data sets, we constructed digital elevation models (DEMs) and analyzed topographic changes between the three years. The results showed that the sand of the study area decreased in volume from 2008 to 2014, because sand supply from the nearby beach was blocked by coastal forests. The sand volume temporarily increased from 2014 to 2018, because of the dune nourishment conducted in 2017. It seems that the upper part of the sand dune has shrunk, but the sand at the bottom has increased over the last decade.

• 한국지형학회지
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• 제25권3호
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• pp.43-55
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• 2018

This study aimed to identify different sedimentary environments of Gochang coast according to geomorphic conditions of each bore hole. To achieve the aim, this study utilized the classification of sedimentary environmental conditions of surface sediment, which was based on grain size distribution characteristics.In other words, three sedimentary environmental conditions ofsandy flat + sand beach, coastal sand dune and weathered bedrock soil, which were distinguished based on grain size distribution characteristics of mean-sorting for surface sediments, were applied to the sediments of bore holes. Four sedimentary environments could be identified in Gochang coast. First, the lake sedimentary environment originated from terrestrial sediments seems to have been dominated by weathered bedrock soil that the surface flow has deposited in a coastal wetland or a boundary, which is affected by the sea. Second, the lake sedimentary environment that is little affected by coastal sand dunes is located at the center of a valley, which is connected to the land, and the dune slack of Saban-ri. The surface flow of weather bedrock soil is the main source of deposits. However, there seems to have been a temporary influence of the sea. Third, the lake sedimentary environment that is strongly affected by coastal sand dunes is located at the dune slack of Yeongjeong-ri. This environment shows traces of a change from a coastal sand dune into the dune slack. Finally, the coastalsand dune sedimentary environment, which wasinvestigated by boring the current coastal sand dune, shows a temporary influence of the land but seems to have maintained the overall stability. Consequently, this study demonstrated that the grain size distribution characteristics of the present surface sediments could be effectively applied to identify the sedimentary environments of the paleo bore hole sediments. In addition, the paleo change of sedimentary environment could also be identified in many places of Gochang coast. If the results of this study are combined with the age dating and geochemical analysis in future works, the paleo environmental change in Gochang coast will be restored more precisely.

• 한국지형학회지
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• 제17권1호
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• pp.85-93
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• 2010

2007년 12월에 발생했던 태안 해안 기름유출 사고 직후, 신두 해안사구 전면에 기름 성분이 사구지대로 비산되는 것을 방지하기 위한 그물형 사구울타리가 설치되었다. 이 연구의 목적은 당시에 설치되었던 사구울타리로 인해 나타나는 해빈과 전사구의 지형 변화 특성을 시·공간적으로 파악하고자 하는 것이다. 사구울타리에서의 지형 변화를 계측한 결과 2007년 12월을 기준으로 할 때 해안 전 지역에서 거의 1m에 달하는 모래가 퇴적된 것으로 나타났다. 시기별로는 동계(가을철-봄철)에 퇴적이 우세하게 일어났고, 하계(봄철-가을철)에는 지형변화가 크게 일어나지 않거나 소량의 변화가 부분적으로 나타났다. 지점별로는 전 지역에서 퇴적이 일어났으나 사구지대 북단이 가장 큰 변화를 보였다. 이러한 결과는 사구울타리가 설치된 후 해빈과 전사구 일대에 다량의 모래가 퇴적되어 교란되었던 지형단면이 자연스럽게 복원되었다는 것을 의미한다.

• 한국환경복원기술학회지
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• 제16권1호
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• pp.55-69
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• 2013

The phytosocialogical study on the coastal sand dune vegetation of the East Coast was carried out. 180 phytosociological relev$\acute{e}$s of 62 sites in the East Coast were used in this study. In addition, already published syntaxa and the phytosociological hierarchy in Korea and Japan were used and comparative analyses of syntaxonomy, synecology, syngeography, and syndynamics were performed in the study. In this study, the flora was investigated 30 families, 66 genera, 77 taxa and 3 vegetation types were identified : the coastal drift-line annual communities (Calystegio soldanellae-Salsoletum komarovii), the dune glasslands communities (Elymo-Caricetum kobomugi, Carex kobomugi typical community, Elymus mollis community, Calystegia soldanella community, Zoysia macrostachya community, Cynodon dactylon community, Carex pumila community), and the dune shrubs communities (Linario-Viticetum rotundifoliae, Vitex rotundifolia community, Rosa rugosa community). The aspect of transition in the coastal sand dune vegetation of the East Coast were identified as follows : (1) reduced constancy degree and cover degree of Glehnia littoralis in each community; (2) lack of Ischaemum anthephoroides in Linario-Viticetum rotundifoliae (3) simplified species composition in Vitex rotundifolia community. Unstable habitat condition by external interference seemed to has caused the reduction of 2 taxa, Glehnia littoralis and Ischaemum anthephoroides, that usually grow in the second dune. In addition, we found changes in the distribution of the dune shrub communities influenced by rising temperature of the East Coast as results of the global warming. The results on the distribution of the dune shrub communities in this study demonstrated that the limit of the Rosa rugosa community made $0^{\circ}$ 44'N to the North and the vegetative limit of the Vitex rotundifolia community made $0^{\circ}$ 28'N to the North, respectively compared with the previously phytosociological studies. This study investigated the coastal sand dune vegetation, syntaxonomy, habitat condition and human disturbunce of the East Coast, and this will provide important information as basic data for the coastal ecosystem.

• 한국지반공학회논문집
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• 제28권9호
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• pp.17-22
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• 2012

초대형 사구지역 내 철도공사를 위한 대단위 토공작업을 수행하는 경우, 공사 중 및 공사 후 모래바람에 의한 철도선로의 침식 등으로 인해 철도운행에 큰 지장을 초래할 수 있기 때문에 모래바람에 의한 철도노선 내 모래퇴적 방지공의 계획수립이 매우 중요하다. 효과적인 모래퇴적 방지공을 위해서는 적절한 토공설계뿐만 아니라 펜스 시스템과 같은 직접적 모래바람 억제방법 등에 대한 통합적이고 신중한 고려가 필요하다. 하지만, 현재까지 사용된 여러 방법들을 조사해 본 바에 의하면 모래사막 내 철도건설 시 가장 일반적이고 효과적인 모래퇴적 방지공은 없으며, 모래사막의 사구의 지형학적 연구를 토대로 철도선로 및 모래바람으로부터의 철도선로 보호 구조물 등에 대한 철저한 유지보수 계획의 수립이 더 효과적이고 경제적일 것으로 판단되었다. 본 연구에서는 UAE에서 수행되는 프로젝트 지역 내 사구지역의 대단위 및 특정지역 지형에 대한 조사, 분석을 수행하고, 문헌고찰, 항공사진, 위성사진, 현장조사 등을 통해 프로젝트 지역 내 사구의 이동경로, 이동속도를 추정하여 모래바람에 의한 철도선로 침식방지 구조물의 설계 및 유지 보수 계획 수립에 기여하는 것에 그 목적을 두었다.

• 한국환경복원기술학회지
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• 제6권6호
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• pp.29-40
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• 2003

Shindoori dune, about 2,000,000$m^2$ in area, is located in the west of the middle area in Korea. Around the sand dune, many diagnostic plants and animals are populated, so it is considered a very important ecosystematic area. This study was carried out to establish for conservation and restoration in Shindoori dune. Our surveys have been accomplished from October, 2002 to September, 2003. Plant communities formed around the sand dune in Shindoori were divided into several patterns and analysed. They have been divided into 9 communities. Community A : Carex pumila community, B : Carex kobomugi community, C : Elymus moWs community, D : Imperata cylindrica var. koenigii community, E: Rosa rugosa community, F: Ischaemum anthephoroides community, G: Vitex rotundifolia community, H : Lathyrus japonica community, I : Oenothera biennis community. The flora surveyed in these communities was constituted of 19 families, 44 genera, 8 varieties, and 40 species. Wild plants such as Calystegia soldanella, Artemisia capillaris, Avena fatua, Mertensia asiatica, Glehnia littoralis and Zoysia sinica were mostly light loving plants and higher resistant plants against the salty wind. Our result from the ranking all surveyed areas by the Bray-Curtis ordination method was very similar to the results from phytosocialogical table work.

• 한국농림기상학회지
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• 제15권1호
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• pp.9-16
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• 2013

해안사구는 해양생태계에서 내륙생태계로 이행하는 생태 이행대(ecotone)로서 중요한 생태계이다. 이러한 독특한 생태계의 서식지 특성 분석의 일환으로 우리나라에서 사구가 가장 넓게 분포하는 지역인 태안해안국립공원에서 미기상 요인(기온, 지온, 상대습도, 토양수분함량, 강우량 및 일사량, 풍향 및 풍속)의 통년 관측자료를 이용하여 계절변화를 분석하였다. 해안사구 초지생태계에서 미기상 요인의 계절변화는 산림생태계와 비교하여 상대적으로 고온 다습하며 6월과 7월에 집중 강우를 보였다. 토양온도는 기온보다 평균 $2{\sim}3^{\circ}C$ 높은 상태로 계절변화 하였으며 토양수분함량은 연중 10% 미만으로 매우 건조한 특성을 나타내었다. 또한 2011년 최고 풍속은 156.72m $s^{-1}$(10월 7일)를 기록하였고 현지 측정한 풍향과 기상청 자료는 상이함을 알 수 있었다. 해안사구 초지생태계의 서식지 특성을 더 잘 이해하기 위해서는 이러한 미기상 요인의 통년 장기관측이 필요할 것이다.

• 한국경제지리학회지
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• 제12권4호
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• pp.702-717
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• 2009

본 연구에서는 전국민을 대상으로 조건부가치측정 설문을 이용하여 신두해안사구의 이용가치 및 비이용가치를 포함한 신두해안사구의 보전에 대한 지불의사금액 및 신두해안사구의 자산가치를 추정하였다. 신두해안사구 보전을 위한 가구당 지불의사금액은 3,059원(95% 신뢰구간은 2,591원~3,612원)이고, 전국적으로는 440억 2,700만원(95% 신뢰구간은 372억 8,900만원~519억 8,200만원)에 이르렀다. 신두해안사구의 자산 가치는 7.5%의 할인율을 적용하면 5,870억원(95% 신뢰구간은 4,972억원~6,931억원)이다. 여기서 직접 이용가치에 기인한 자연자산의 가치 부분이 13.4%인 787억원(95% 신뢰구간은 666억원~929억원)이고, 간접 이용가치에 기인한 자연자산의 가치 부분이 30.2%인 1,773억원(95% 신뢰구간은 1,501억원~2,093억원)이다. 한편 선택가치에 기인한 자연자산의 가치 부분은 19.4%인 1,139억원(95% 신뢰구간은 965억원~1,345억원)을 차지하고, 보전가치에 기인한 자연자산의 가치 부분은 37.0%인 2,172억원(95% 신뢰구간은 1,840억원~2,654억원)이다.