• Title/Summary/Keyword: dune

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Systems Thinking for the Land Use and Landscape Value of Coastal Dune (해안사구의 토지이용과 경관가치에 대한 시스템 사고)

  • Seok, Youngsun;Song, Kihwan;Chon, Jinhyung
    • Korean System Dynamics Review
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    • v.15 no.3
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    • pp.81-104
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    • 2014
  • This study aimed to suggest the directions for the landscape protection of Sindu-ri coastal dune based on its ecological system. The study investigated ecological systems of the coastal dune followed by damage causes of coastal dune according to the land use change, and landscape value of coastal dune in the study area. In order to construct causal-effect feedback loop, systems thinking was performed. Result of this study showed that the area of coastal dune and the amount of sand are maintained by the interaction with sand beach while they are affected by wind direction, wind speed, and dune plants. It was also found that the changes of land use pattern, increasing commercial area, and planted windbreak forest damaged to the coastal dune. In addition, size of coastal dune and growing number of dune plants increased landscape value of coastal dune and tourist draw. However increasing tourists have constantly affected land use changes and have damaged to coastal dune area. In sum, planning for land use regulation, rest-year system areas, promotion and education for coastal dune, dune plants protection, and windbreak management should be taken into account for landscape protection in coastal dune.

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Geomorphological Characteristics and OSL Ages of the Moraeul dune in Daechoengdo Island, South Korea (대청도 모래울 사구의 지형 특성과 OSL 연대)

  • Choi, Kwang Hee
    • Journal of The Geomorphological Association of Korea
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    • v.27 no.4
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    • pp.1-11
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    • 2020
  • Coastal dunes play an important role in coastal defense. The Moraeul dune in Daecheongdo Island is representative in this regard. However, there is little knowledge, concerning the morphology, grain size, and formation timing of the dune. This study investigated the geomorphological characteristics of the Moraeul dune using topographic surveys, grain size analyses, and OSL dating. The dune was classified as 'single accreted foredune', which was developed under dense vegetation cover and efficient sand trapping. The dune consisted of fine to medium sand with 1.6Φ of mean grain size, and was covered with pine trees (> 100 years old). The samples from the upper part of the dune yielded quartz OSL ages ranging 0.5 ~ 0.7 ka. Therefore, it is likely that the dune developed at least before the Little Ice Age and became what it is today about one century ago.

Coastal Sand Dune Vegetation in Kyungpook Province (경북의 해안사구식생)

  • 정용규;김종원
    • The Korean Journal of Ecology
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    • v.21 no.3
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    • pp.257-262
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    • 1998
  • A syntaxonomical study about coastal sand dune vegetation in Kyungpook province was carried out. This study was accomplished by the methods of classical block-structure seeking and had-sorting of the $Z\"{u}rich-Montpellier$ School. The main purpose of this study is to clarify the syntaxonomical, synecological, syngeographical and syndynamical characteristics of coastal sand dune vegetation in Kyungpook province. The dune shrubs communities in Kyungpook province are consisted of 2 communities: Vitex rotundifolia community of southern type and Rosa rugosa community of northern type. And the dune grasslands communities are also consisted of 2 communities: Elymo-Caricetum kobomugi Ohba, miyawaki et $T\"{u}xen$ 1973 and carex kobomugi typical community. The subsidiary knowledges from this study will make possible to accumulate qualitative and quantitative information in the distribution pattern of coastal sand dune vegetation, and also will provide practical information for national biodiversity and conservation of coastal ecosystem.ecosystem.

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The Geomorphology and the Sediment Characteristics of Sagye Coastal Dune, Jeju Island, Korea (제주도 사계 해안사구의 지형과 퇴적물 특성)

  • Seo, Jong-Cheol;Sohn, Myung-Won
    • Journal of the Korean association of regional geographers
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    • v.12 no.6
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    • pp.631-644
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    • 2006
  • The study area is a pocket beach which consisted of sandy beach, dune, agricultural land and residential area etc. The coastal dune area is classified to foredune, dune plain, secondary (or back) dune. The foredune area is covered by herbaceous dune plants(ex. Carex kobomugi, Wedelia prostrata, etc.), whereas the dune plain area is covered by herbs and shrubs(Vitex rotundifolia). The most inner area, secondary dune, is planted by pine forest(Pinus thunbergii). The mean size of the beach and dune sediments ranges from 1.1 to $1.8{\Phi}$, which mean these values are higher than normal sediments. Sorting and Skewness is $0.6{\sim}-1.2{\Phi}$ and $-2.7{\sim}1.6{\Phi}$ respectively. We found that the soil formation process in the secondary dune area has been progressed rapidly from the analysis of fine grain content, organic matter content, and CEC.

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Engineering characteristics of dune sand-fine marble waste mixtures

  • Qureshi, Mohsin U.;Mahmood, Zafar;Farooq, Qazi U.;Qureshi, Qadir B.I.L.;Al-Handasi, Hajar;Chang, Ilhan
    • Geomechanics and Engineering
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    • v.28 no.6
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    • pp.547-557
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    • 2022
  • Dune sands are poorly graded collapsible soils lacking fines. This experimental study explored the technical feasibility of sustainable invigoration of fine waste materials to improve the geotechnical properties of dune sand. The fine waste considered in this study is fine marble waste. The fine waste powder was mixed with dune sand at different contents (5, 10,15, 20, 25, 50%), where the gradation, void ratio, compaction, and shear strength characteristics were assessed for each fine marble waste -dune sand blend. The geotechnical properties of the dune sand-fine marble waste mix delineated in this study reveal the enhancement in compaction and gradation characteristics of dune sand. According to the results, the binary mixture of dune sand with 20% of fine marble waste gives the highest maximum dry density and results in shear strength improvement. In addition, a numerical study is conducted for the practical application of the binary mix in the field and tested for an isolated shallow foundation. The elemental analysis of the fine marble waste confirms that the material is non-contaminated and can be employed for engineering applications. Furthermore, the numerical study elucidated that the shallow surface replacement of the site with the dune sand mixed with 20% fine marble waste gives optimal performance in terms of stress generation and settlement behavior of an isolated footing. For a sustainable mechanical performance of the fine marble waste mixed sand, an optimum dose of 20% fine marble waste is recommended, and some correlations are proposed. Thus, for improving dune sand's geotechnical characteristics, the addition of fine marble waste to the dune sand is an environment-friendly solution.

Study on the Status and Socio-Economic Characteristics of Coastal Sand Dune in South Korea (우리나라 해안사구의 현황과 사회·경제적 특성 고찰)

  • Kang, Jihyun;Seo, Jongcheol;Rhew, Hosahng;Kim, Taesuk;Oh, Jeongsik;Lee, Jaeho;Oh, Sujeong;An, Sejin
    • Journal of The Geomorphological Association of Korea
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    • v.24 no.3
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    • pp.149-159
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    • 2017
  • Coastal dunes have many environmental and ecological socio-economic importances; various human activities, however, have impaired their structures and functions over the years. In 2016, environmental survey on coastal sand dune was carried out to report the present status and update the coastal sand dune list in 2001. This research analyzed the survey data in terms of geomorphological and socio-economic aspects. A list of the 189 coastal sand dune and information was updated by province. A 36.5% reduction in coastal sand dune area have been identified for using agricultural land, development area since the approximately 1940-50s. Development area in coastal sand dune covered small area as 5%, the use intensity was relatively hard. Furthermore, the difference by province also showed. Approximately 80% of the development area was concentrated in 20% of total sand dune several sand dune. It is generally accepted that coastal sand dunes were exposed high development pressure. However the result means that the general brief dose not apply for all sand dune. Therefore, characteristics of each sand dune should be analyzed and concerned the diverse management plans.

Morphological and Textural Characteristics of the Beach-dune System in South Korea, with the Possibility of a Dune Type Scheme Based on Grain-size Trend (국내 해안의 해빈-해안사구 지형 및 퇴적물 특성과 입도기반 사구유형 분석)

  • Rhew, Hosahng;Kang, Jihyun
    • Journal of The Geomorphological Association of Korea
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    • v.27 no.3
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    • pp.53-73
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    • 2020
  • Morphology and grain size distribution of coastal dunes should be well documented because they are critical to dune's buffering capacity and resilience against storm surges. The nationwide coastal dune survey produced the dataset, including beach-dune topographic profiles and grain size parameters for frontal beaches, foredunes, and inland dunes. This research investigated the dataset to describe geomorphic and textural properties of coastal dunes: foredune slopes, dune heights above approximately highest high water, mean size, and sorting, together with associated variables of coastal setting that influence coastal dunes. It also explores the possibility of a dune type scheme based on gran size trends. The results are as follows. First, the coast in which dunes are developed is the primary control on foredune morphology and sediment texture. Coastal dunes on the east coast were developed more alongshore rather than inland, with gentler slopes on the higher ground and out of coarser sand. The shore aspect contributes to this pattern because the east coast cannot benefit from prevailing northwesterly. Second, grain size trends from beaches through foredunes to inland dunes were little identified. Third, 12 dune types were identified from 69 dunes, showing the indicative capability for the status of beaches and dunes. We confirmed that the dataset could increase our understanding of the overall characteristics of coastal dune morphology and texture, though there is something to be improved, for example, establishing the refined and comprehensive field survey protocol.

A Luminescence Dating for a Relict Dune from the Sindu Dunefield (신두리 지역의 고사구(古砂丘)에 대한 OSL 연대 측정)

  • Seo, Jong-Cheol
    • Journal of the Korean association of regional geographers
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    • v.11 no.1
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    • pp.114-122
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    • 2005
  • To find out the buried age of the relict dune sediments, a luminescence dating bas conducted for a relict dune from the Sindu dunefield on the Taean Peninsula. It shows that the deposition of the dune sands at 3m depth began about 690$\sim$730 years ago. From 3m to l.5m depth, the lower part of the dune bas remained stable, but a relict dune deposit appear at 1.3m depth. This part yields an age of about 68 years. The two samples that were collected from the lower part of the dune at depths of the 1.5 m and 3.0 m below the surface show a net accumulation rate of around 0.75 cm/y which is relatively slow for a coastal dune. The chronology obtained in this study demonstrates that a significant amount of sediments has been replaced or remobilized in the area over the past 1000 years, and there was at least a soil formation process during the same time period. These suggest that a new approach is necessary to identify the formation age of the so-called paleo-dune at the Sind dunefield.

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Photosynthetic characteristics and chlorophyll of Vitex rotundifolia in coastal sand dune

  • Byoung-Jun Kim;Sung-Hwan Yim;Young-Seok Sim;Yeon-Sik Choo
    • Journal of Ecology and Environment
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    • v.47 no.3
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    • pp.103-116
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    • 2023
  • Background: This study analyzed the physiological adaptations of a woody plant, Vitex rotundifolia, in Goraebul coastal sand dunes from May to September 2022. Environmental factors and physiological of plants growing under field and controlled (pot) conditions were compared. Results: Photosynthesis in plants growing in the coastal sand dunes and pots was the highest in June 2022 and July 2022, respectively. Chlorophyll fluorescence indicated the presence of stress in the coastal sand dune environment. The net photosynthesis rate (PN) and Y(II) were highest in June in the coastal sand dune environment and July in the pot environment. In August and September, Y(NPQ) increased in the plants in the coastal sand dune environment, showing their photoprotective mechanism. Chlorophyll a and b contents in the pot plant leaves were higher than those in the coastal sand dune plant leaves; however, chlorophyll-a/b ratio was higher in the coastal sand dune plant leaves than in the pot plant leaves, suggesting a relatively high photosynthetic efficiency. Carotenoid content in the coastal sand dune plant leaves was higher in August and September 2022 than that in the pot plant leaves. Leaf water and soluble carbohydrate contents of the coastal sand dune plant leaves decreased in September 2022, leading to rapid leaf abscission. Diurnal variations in photosynthesis and chlorophyll fluorescence in both environments showed peak activity at 12:00 hour; however, the coastal sand dune plants had lower growth rates and Y(II) than the pot plants. Plants in the coastal sand dunes had higher leaf water and ion contents, indicating that they adapted to water stress through osmotic adjustments. However, plants growing in the coastal sand dunes exhibited reduced photosynthetic activity and accelerated decline due to seasonal temperature decreases. These findings demonstrate the adaptation mechanisms of V. rotundifolia to water stress, poor soils, and high temperature conditions in coastal sand dunes. Conclusions: The observed variations indicate the responses of the V. rotundifolia to environmental stress, and may reveal its survival strategies and adaptation mechanisms to stress. The results provide insights into the ecophysiological characteristics of V. rotundifolia and a basis for the conservation and restoration of damaged coastal sand dunes.

Vertically Development Processes of Jangho-ri Coastal Dune, West Coast of Korea (고창 장호리 해안사구의 수직 발달 과정 연구)

  • Han, Min;Kim, Jin Cheul;Yang, Dong-Yoon;Kim, Jong Yeon
    • Journal of The Geomorphological Association of Korea
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    • v.23 no.3
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    • pp.79-92
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    • 2016
  • Samples from two boreholes of coastal dune field at Jangho-ri coast, Gochang was studied. These were analyzed by grain size analysis geochemical analysis, and the application of OSL dating method to understand the development during the Holocene. The boreholes SB8 and SB9 were classified into three different sedimentary layers by their mean grain size and geochemical characteristics. The results revealed that the upper sand layer is equivalent to the present coastal dune layer, which developed since 1,200 years ago; the silt layer in the middle to the dune slack or lagoon sedimentation layer, which developed between 1,200 and 6,000 years ago; and the sand layer at the bottom to the paleo coastal dune that developed between 6,000 and 7,000 years ago. It was proposed that the forming material of current coastal dune was supplied from the sandy flat in coastal area, while the middle silt layer was supplied from the weathered soil of a bed rock by the comparison with material of surrounding area. In the case of coastal dune, concentrated layer of sands were identified which were buried about 300 and 1,200 years ago, which is identified as the little ice age. This study confirmed the development of Jangho-ri coastal dunes after Holocene Climate Optimum period, and it is likely to assist in the understanding of coastal dunes development.