• Title/Summary/Keyword: 사구 지형

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Morphological Changes of the Beach and Foredune by Sand Fences - A Case of Shindu Coastal Dune Area - (사구울타리 설치 후 해빈과 전사구의 지형 변화 - 신두리 해안사구를 사례로 -)

  • SEO, Jong Cheol
    • Journal of The Geomorphological Association of Korea
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    • v.17 no.1
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    • pp.85-93
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    • 2010
  • After the notorious Taean Oil spill in Dec. 2007, a series of sand fences made of fishing net were installed in front of foredune in Shindu dune area. This paper aims to understand the temporal and spatial characteristics of morphological changes of the beach and foredune. About 1m high sand accumulated around sand fences for the last 2 years. While a lot of sand deposited during the winter season (from autumn to spring), small amount of sand eroded and deposited during summer season (from spring to autumn) without big morphological changes. These results mean that sand fences help nature deposit sand near beach and foredune area.

Erosion and Recovery of Coastal Dunes after Tropical Storms (태풍의 통과로 인한 해안사구 지형의 침식과 회복)

  • Choi, Kwang Hee;Jung, Pil Mo;Kim, Yoonmi;Suh, Min Hwan
    • Journal of The Geomorphological Association of Korea
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    • v.19 no.1
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    • pp.17-27
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    • 2012
  • Coastal dunes help stabilize the coastal landscape and protect the hinterland through dynamic interaction with sand beaches. Sometimes dune erosion occurs during the tropical cyclones, while dune recovery may naturally follow after the event. As the typhoon Kompasu passed through the Korean Peninsula early-September in 2010, it caused a rise in water in association with the storm, wave run-ups, and heavy rains in coastal areas. As the result, coastal dunes along the west coast of Korea were severely damaged during the storm. However, the degree and extent of erosion and recovery of dunes were found to be related with the condition of beach-dune systems including gradients of foreshore and front slope of the dune, sediment supply, vegetation, wind activity, and human interferences. Some dunes retreated landward more and more after the erosional event, while others recovered its original profile by aeolian transport processes mainly during the winter season. Vegetated dunes with pine trees were less recovered after the erosion than grass-covered dunes. In addition, dunes with artificial defense were more eroded and less recovered than those without hard constructions. According to the observation after the severe storm, it is likely that the sand transport process is critical to the dune recovery. Therefore, the interactions between beach and dune must be properly evaluated from a geomorphological perspective for the effective management of coastal dunes, including natural recovery after the erosion by storm events.

The morphological changes of the beach and dune using by periodical measurements (주기적 지형 측량을 통한 해빈과 해안사구의 지형변화: 충남 보령시 소황사구를 사례로)

  • KANG, Dong Kyun;SEO, Jong Cheol
    • Journal of The Geomorphological Association of Korea
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    • v.19 no.2
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    • pp.69-79
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    • 2012
  • The aim of this study is to analyze the mid-term changes of beach and dune morphology at Sohwang beach, Korea using by Total Station. Measurements executed 4 times during two year. Based on ArcInfo as point cloud obtained through precise measurement data by Total Station, alteration of beach and dune was analyzed at DEM, of which cell size is about 1m. Since these artificial constructions have influenced current systems of this region, the large-scale sand movements above mentioned have occurred around the jetty and the sea-wall. There occurred sedimentation in the north of the Jetty and erosion in the south of the Jetty, which is installed at the central part of object area. The direction of recent topographic development does not coincide with that of wind, and, rather, topographic changes occurred mainly at beaches and dunes due to the transformation of coastal water flow caused by artificial structure nearby. If precise measurement is conducted periodically, and long term monitoring is carried out by installing equipment measuring movement pattern of sediment around artificial structure, cause of topographic change around the object area could be discovered.

Analysis of Geomorphological Changes using RS and GIS techniques in Shinduri coastal dunefield (원격탐사와 GIS 기법을 이용한 신두리 해안사구지대의 지형변화 분석)

  • Seo, Jong-Cheol
    • Journal of the Korean association of regional geographers
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    • v.8 no.1
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    • pp.98-109
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    • 2002
  • The long term land-cover changes and the pattern of morphological changes in foredune ridges and unvegetated dunes were investigated for about 30 years through analysing aerial photographs in Shinduri coastal dunefield, Korea. As a result, forested dune area increased while unvegetated dune area decreased continuously since 1967. Foredune ridges retreated landward about 80m away from the former coast-line in the middle part while they advanced seaward after construction of dike in the northern part during last 3 decades. Unvegetated dunes in the middle part of the dunefield were eroded at seaward side and moved landward away. These facts mean not only coastal dune area has been affected by man-made effects such as afforestation and coastal developments but also shinduri coastal dune area has been stabilized by plants and has been negative sediment budget.

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충청남도의 해안사구

  • 강대균
    • Proceedings of the KGS Conference
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    • 2003.05a
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    • pp.51-55
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    • 2003
  • 해안사구는 사빈으로부터 모래를 공급받아 형성되는 지형이다. 사빈은 조차에 비해 파랑의 작용이 활발한 해안에 발달한다. 해안사구는 일반적으로 모래의 공급이 풍부하고 바람이 탁월한 해안에 광범하게 발달된다. 우리나라와 같은 온난ㆍ습윤한 지방의 해안사구는 대부분 직생으로 덮여 있다. 식생은 해안사구의 발달을 돕는다. 사빈과 해안사구는 해수욕장으로 이용되어 자원으로서의 가치가 높다. (중략)

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협제동굴지대의 동굴지형연구

  • 강상배;홍현철
    • Journal of the Speleological Society of Korea
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    • v.25 no.26
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    • pp.82-130
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    • 1991
  • 이 동굴지대의 지형을 개관하면 한라산서북사면 기슭의 해안저평지대라고 하겠다. 주로 해안사구가 전개되고 있는 솔밭이 많은 지형이다. 우선 분포 지역을 살펴보면 북서 해안의 한림읍 금릉리 동쪽으로부터 협재리에 이르는 해안인데, 내륙으로 2.7km까지 사구가 발달되어 있고, 애월읍 곽지리 해안에도 약간 분포하고 있다.(중략)

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The Roles of Wind Shadow Aspect Ratio upon the Behaviors of Transverse Dunes : A Dynamics Analysis on the Behavior Space (바람그늘의 기울기가 횡사구의 지형발달에서 담당하는 역할 -거동 공간상의 동역학적 분석을 중심으로-)

  • RHEW, Hosahng
    • Journal of the Korean association of regional geographers
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    • v.22 no.4
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    • pp.887-911
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    • 2016
  • The empirical law that transverse dunes migrate inversely with their heights leads logically to the prediction that multiple dune ridges will converse to a single huge dune by merging. This contradicts the existence of the steady state dune fields on the Earth. The recent studies have emphasized dune collisions as a key mechanism to the stability of dunefield. The roles of wind shadow aspect ratio, however, have yet to be fully explored. This research aims to investigate the potential roles of wind shadow aspect ratio in the dynamical behaviors of transverse dune field. The simplified model is established for this, based upon allometric properties of transverse dunes, wind speedup on the stoss slope and sand trapping efficiency. The derived governing equations can be transformed to the zoning criteria and vector field for dune evolution. The dynamics analysis indicates that wind shadow aspect ratios do not produce convergent areas on the behavior space; rather, they just act as one of the factors that affect the trajectories of dune evolution. Though the model cannot represent the stability of dune field, but seem to produce a reasonable exponent for dune spacing-height relations.

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Applicability of Wind-Vegetation Model in Small Scale Sand Dunes (소규모 사구 지역 바람-식생모델 적용성 분석)

  • Choi, Seok Keun;Choi, Jae Wan;Park, Sang Wook;Jung, Sung Heuk;Lee, Soung Ki
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.35 no.6
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    • pp.545-552
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    • 2017
  • Aeolian dunes are typical sand dunes which are maintained and developed by interactions of earth surface, wind and vegetation. Developing a model which can predict the changing phenomena of these sand dunes is vital in enhancing the efficiency of understanding and management of terrains such as land degradation. In the existing models, however, there is lack of studies on the long - term behaviors of the sand dunes and application to actual topography. Therefore, this study applied the wind-vegetation model considering vegetation to the actual topography and analyzed the applicability of the wind-vegetation model by analyzing the long-term behaviors and comparing them with actual data. Through analysis, study found out that use of wind-vegetation model and data from unmanned aerial vehicle is effective in analyzing the changes of actual dune topography. Except for the boundary, the error of about 1m was generated compared with the change of the actual dune topography.

The Effective Wind Velocity and the Patterns of Morphological Change in the Coastal Dune Area (해안사구에서의 유효풍속과 지형변화)

  • Sea, Jong-Cheol
    • Journal of the Korean association of regional geographers
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    • v.10 no.3
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    • pp.667-681
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    • 2004
  • This research is aimed to investigate the relationship of the effective wind velocity and the morphological change in coastal dune at Sindu-ri in Korea. Sediment flux was estimated by the measurement of elevation change along eight transects deployed in the study area from July 1999 to July 2000. The results of this study indicated that. first. based on the occurrence of morphological change and winds effective for sand movement. two distinct seasons were identified: a season of deposition and that of erosion. During the depositional season, spanning from November to April, effective winds were dominant and sand accumulation occurred mainly in foredunes and sequentially in dune plains. During the erosional season, from May through October, volume change was small and erosion or sand loss occurred mostly at the dunefoot of foredunes. Secondly, the research revealed that the sediment budget of Sindu coastal dune turned out to be surplus on the whole, but there are some regional differences. Deficit budgets were observed partly in secondary dunes. The utmost northern part of Sindu coastal dune was provided with abundant sand, whereas the central and northern parts were poorly supplied.

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Seasonal changes in coastal dunes and its implication, Sohwang-ri, in Chungnam Province (보령 소황리 전사구의 계절별 지형변화 특성과 그 의의)

  • JUNG, Pil Mo;CHOI, Kwang Hee;KIM, Yoonmi
    • Journal of The Geomorphological Association of Korea
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    • v.19 no.4
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    • pp.109-122
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    • 2012
  • Topographic changes in the foredune in Sohwang-ri, Boryeong, Chungnam Province was analyzed over the last two years. Seven cross-sections and one permanent plot ($20m{\times}50m$) were periodically studied based on erosion and deposition measurement, in addition to vegetation monitoring and measurement of wind using an automatic weather station. The sand dunes usually grew from late winter to spring and the growth occurred in a period of strong northwesterly winds. From March to April, heavy sedimentation was observed on the front section of the foredune and sand piled up to ca. 30cm to the ca. 25m landward from the high tide line. It is likely that increased wind force and growth of vegetation played a major role in transportation and sedimentation of sand. Meanwhile, the lower part of the sand dunes was eroded when typhoon and spring tide caused a rise in sea level. The transition zone of beach and dune was usually affected by sea water but some frontal slopes were entirely influenced, resulting in dune scarps. The eroded scarps were naturally restored to their original state as time passed.