• 제목/요약/키워드: Beach sand

검색결과 210건 처리시간 0.036초

부산일원(釜山一圓) 연안해빈사(沿岸海賓砂)의 퇴적학적(堆積學的) 연구(硏究) (Sedimentological Study of Littoral Beach Sand in Busan Area, South Korea)

  • 이유대;최광선
    • 자원환경지질
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    • 제16권2호
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    • pp.65-78
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    • 1983
  • This report deals with the sedimentological study of the littoral sand of beaches in the Busan area. The purpose of this report is to know the grain size, mineralogical composition, heavy mineral and clay mineral of the beach sands, and gravity measurements of the Nagdong River Deltas. 1) As a whole, the littoral sand of the beaches are composed of uniformly medium grained, moderately sorted and nearly symmetrical. The barrier sand of the Nagdong Estuary is composed of fine grained, well sorted and nearly symmetrical. 2) The littoral sand of the beaches is transported by saltation and rolling. The barrier sand of the Nagdong Estuary is transported by suspension and saltation. 3) In the littoral sand of the beaches, the ratio of feldspar to quartz is 1 :2.31 and in the barrier sand of the Nagdong Estuary 1:1.40. 4) The content of heavy mineral of samples ranges from 0.54 to 3.87 %. The principal heavy minerals are hornblende, pyroxene, epidote, garnet, leucoxene, zircon, apatite, magnetite, hematite and ilmenite with minor accessories of rutile and olivine. 5) The x-ray diffraction analysis of the clay mineral informs the existence of quartz, feldspar, kaolinite and montmorillonite. The montmorillonite is considered to have been derived from the alteration of acidic volcanic rocks. 6) To determine the depositional structure of the Nagdong Estuary, Gravity measurements were made. Free air anomaly ranges from 14.5 mgal to 33.5 mgal and Bouguer anomaly ranges from 14.3 to 23.5 mgal and both are closely related to the topography. According to the interpreted layer structure, the upper layer composing sand, silt and clay, the intermediate layer composing sand with gravel, the lower layer composing weathered and soft rock, and bed rock composing hornfels or andesite. 7) The depositional environments of the study, the littoral area is dominated by the marine environment and the Nagdong Estuary by the mixed environment.

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제주도 이호.함덕 해빈퇴적물의 계절적 변화에 관한 연구 (Seasonal Variations of Iho and Hamdeok Beach Sediments in the Jeju Island, Korea)

  • 윤정수;박용성;김태정;박상운
    • 자원환경지질
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    • 제41권2호
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    • pp.243-252
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    • 2008
  • 제주도의 주요 해수욕장인 이호와 함덕해빈에 대한 해빈단면 조사와 입도분석 연구를 통해 해빈퇴적물의 분포경향과 해빈특성을 파악하고, 폴대와 포사기 조사를 통한 계절별 해빈사의 이동방향과 이동량 및 해빈지형 변화상태를 파악하였다. 이호해빈은 중조립질 모래로 구성되어 있고 총길이 590m이며, 경사는 하계 12.3$^{\circ}$, 동계 10.8$^{\circ}$로 하계가 다소 높은 편이다. 함덕해빈은 패각편 모래로 구성되어 있고 총길이 950m이며, 경사와 폭은 각각 하계 5.7$^{\circ}$, 114.5m, 동계 7.4$^{\circ}$, 97.4m이다. 해수중의 해빈 부유사의 이동량은 동계가 33.2 mg/l로 하계의 4.5 mg/l 보다 많았고 주로 북동 방향에서 해빈모래가 공급되고 있었다. 이호해빈은 해빈 동쪽에 축조된 방사제의 영향으로 모래유실에 의한 해빈변형이 일어나고 있었고, 함덕해빈은 해빈 중앙부와 애도지역에서 북서계절풍에 의한 사구쪽으로 표사이동이 일어나고 있다.

원격탐사 자료를 이용한 천수만 간석지 환경변화에 관한 연구 (A Study on the Environment Change of Tidal Flat in the Cheonsu Bay Using Remotely Sensed Data)

  • 장동호;지광훈;이현영
    • 환경영향평가
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    • 제11권1호
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    • pp.51-66
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    • 2002
  • The purpose of this study is to analyze the geomorphological environment changes of tidal flat in the Cheonsu Bay. Especially, it centers on the changes in the sedimentary environment using remote sensing data. Multi-temporal Landsat data and topographic maps were used in this study. The results are summarized as follows: the tidal flat of Cheonsu Bay changes in many ways depending on the direction of the tidal current. In the neighborhood of Ganwoldo, the scale of the tidal flat has continuously been expanded due to the superiority of sedimentation after a tide embankment was built. When we analyzed the grain size of sediments and implemented in-situ field survey, it was found that the innermost part of the bay consists of a mud flat, with the midway part mixed flat, and the nearest part to the sea sand flat. On the other hand, in the neighborhood of Seomot isle and its beach, sedimentation is superior in the eastern part whereas erosion is superior in the western part. In other words, the western coast of the beach is contacted with the open seas and under much influence of ocean wave. The eastern coast is placed at the entrance of the bay and has sand bar and tidal flat developed due to submarine deposits that are accumulated on the sea floor by the tidal current. In conclusions, remote sensing methods can be effectively applied for quantitative analysis of geomorphological changes in tidal flat, and it is expected that the proposed schemes can be applied to another geomorphological environments such as beach, sand dune, and sand wave.

경기도 해수욕장 모래의 안전성 확보를 위한 선행연구 (Preliminary Research on Securing the Stability of Sandy Beaches in Gyeonggi Province)

  • 최윤호;변주형;원종무;김종성;신종현;유창숙;정윤하;박민빈;오조교
    • 한국환경보건학회지
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    • 제46권6호
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    • pp.694-701
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    • 2020
  • Objectives: The main purpose of this study is to evaluate heavy metal concentrations (Cd, As, Hg, Pb, Cr6+), particle size distribution, hydrochloric acid solubility, and parasite eggs in sand in five non-designated sandy beaches in Gyeonggi Province. Methods: The sampling sites are five non-designated Gyeonggi-do sandy beaches located in Ansan and Hwaseong. ICP-OES and UV, a Vibratory Sieve Shaker, and PCM were respectively used to analyze heavy metal concentrations, particle size distribution, and parasite eggs in the sand. Results: Heavy metals were detected within the beach's safety management standards and some of the detected As and Pb before and after beach opening were lower than one-quarter of the average value. In addition, the results of the T-test to confirm the As and Pb concentration changes before and after opening showed a significant difference in some beaches. The composition of sand was 86.53% according to the particle size distribution standard (2.0-0.02 mm), and the hydrochloric acid solubility was the highest at Gubongsolsup (4.9%) and the lowest at Bangameo-li (0.2%). Parasite eggs were undetected in all beach sand before and after opening. Conclusions: The safety of heavy metal concentrations in sandy beaches was secured in the selected five beaches in Gyeonggi Province. However, continuous efforts are required to make Gyeonggi-do's beaches suitable according to the Act on the Use and Management of Beaches.

시계열 분석을 통한 송도해안의 해안사구 이동경로 분석 (Analyzing Sand Transfer Path by Songdo Beach Using Time Series Analysis)

  • 한충목;김용석
    • 한국콘텐츠학회논문지
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    • 제9권8호
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    • pp.384-391
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    • 2009
  • 국토의 형상을 결정하는데 있어 중요한 해안 지역은 그 형태와 특성이 변화하는 모습을 가지고 있다. 대규모매립 공사와 크고 작은 해안 지역 개발 등으로 인하여 적절한 이용계획을 수립하는데 문제점이 발생하고 있다. 그 중에서 해안사구는 관광 및 생태학적 측면에서 아주 중요한 역할을 하고 있으며, 이에 대한 연구가 아직은 부족한 실정이다. 본 논문에서는 연구대상의 지역적 범위를 부산 송도해안으로 결정하였으며, 다년간의 RTK-GPS 측량 자료를 근거로 시계열적 분석을 통하여 해안사구의 이동경로를 분석하고자 한다. 송도해안의 경우, 해안선의 길이는 평균 약 620m, 면적은 약 $31,846m^2$으로 나타났다. 송도 해안은 좌우측에 방파제가 설치되어져 있으며, 이로 인해 모래의 유실을 최소화 할 수 있었으며, 매년 일정양의 양빈으로 인하여 꾸준히 해안 사구가 퇴적되고 있음을 알 수 있었다. 또한 7회 측정 결과 해안사구는 좌우측면이 침식되고 중앙부분이 퇴적되어 해안 사구가 전반적으로 앞으로 전진되고 있는 것으로 조사되었다.

태풍에 의한 해빈 퇴적물 조성 및 지형 변화(동해, 나아해빈) (The Change of Beach Sediment Composition and Geography by Typhoon (Naa Beach, East Sea))

  • 이연규;신현옥;이종섭;박일흠;최정민
    • 한국해양환경ㆍ에너지학회지
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    • 제8권3호
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    • pp.122-133
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    • 2005
  • 동해 남부 연안에 위치한 나아해빈을 대상으로 태풍(매미)에 의한 해빈영향을 파악하기위하여 태풍 전 후의 표층 퇴적물조성, 해빈의 해안선 및 단면변화를 관측하였다. 그 결과 해빈의 후빈(backshore)에서는 자갈량이 감소하고 사질함량이 증가하였고, 해빈 전 지역이 침식, 평탄화 되었다. 해저지형변화는 태풍 후 퇴적층 두께 약 4 m까지 침식을 일으키고, 이런 영향은 수심 약 10 m까지 달하며, 해안선은 약 12 m까지 후퇴한 것으로 나타났다. 이것은 해빈에 태풍이 영향을 미칠 때, 높은 파고를 가진 파랑은 해빈의 저부 또는 외해의 저층에 까지 침식작용을 일으키고, 해빈의 상부는 광범위하게 침식된 후 사질로 구성된 퇴적물들이 재퇴적된 것에 기인하는 것으로 생각된다.

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Allozyme Diversity in Korean Populations of Calystegia soldanella and C. japonica (Convolvulaceae): Implications for Conservation

  • Chung, Myong Gi
    • Journal of Plant Biology
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    • 제38권2호
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    • pp.173-180
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    • 1995
  • We investigated levels and distribution of genetic variation in Korean populations of Calystegia soldanella and C. japonica, clonally reproducing herbaceous perennials. Calystegia soldanella is one ofecologically important beach plants growing only on sand and beach dunes in Europe, East Asia, the Pacific Islands, and the west coast of North America. In contrast, C. japonica usually grows on small mounds of paddy fields, roadsides, and waste places with patchy distribution. Starch gel electrophoresis was conducted on leaves collected from 13 populations of C. soldanella and eight populations of C. japonica. The levels of genetic variation of the two species are very comparable; means of expected heterozygosity (Hep) were 0.100 and 0.099 for C. soldanella and C. japonica, respectively. These values were also very similar to those for species with similar life-history and ecological traits. However, the proportion of total genetic diversity partitioned among populations (GST) of C. soldanella (0.146) was considerably lower than that of C. japonica (0.383). In addition, means of Nei's genetic identity (Ⅰ) for C. soldanella and C. japonica were 0.985 and 0.900, respectively, which supports a restricted gene flow resulting from obligate clonal reproduction of C. japonica. Significant differences in allele frequency were detected among populations at eight and nine of nine polymorphic loci for C. soldanella and C. japonica (P<0.01), respecitvely. Considering the ecological importance of C. soldanella, the isolated beach populations coupled with present destruction of natural habitats of the species may result in erosion of genetic diversity in the near future. In this respect, conservation efforts should be focused on those populations that currently maintain the most genetic diversity such as those populations in the eastern and southeastern Korean Peninsula and Hamduck Beach, Cheju Island.

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파랑에 의한 항내진동의 제어에 관한 실험적 연구 (Eaperimental Study on the Control of Harbor Oscillation due to Water Wave)

  • 최한규;이선용
    • 산업기술연구
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    • 제14권
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    • pp.101-107
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    • 1994
  • This study is to investigate harbor oscillation phenomenon according to combination of the wall structures by model experiment in a three dimensional wave basin. Six different types of wall combination were chosen through combination of erect wall, erect dissipation block, and sand beach, wave height at selected points in the harbor were measured by electronic wave gage. Test results show that the wall structure composed solely of erect walls showed generally highest harbor oscillation. Since natural beach shows lower reflection than erect dissipation block do, we thought it would be more efficient to use natural beach for improved harbor oscillation. The result showed, however, that the erect dissipation block are more efficient than natural beach to attain less harbor oscillation. The reason seens that the erect dissipation blocks have better capability to control breaking wave on the surface of the structure.

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2012년 6월 경포해변 해안선의 이상 변화 (Abnormal Change in Gyeongpo Beach Shoreline in June 2012)

  • 이충일;정해근;한문희;이준형;김경렬
    • 한국환경과학회지
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    • 제21권10호
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    • pp.1287-1295
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    • 2012
  • Abnormal change in Gyeongpo beach shoreline in June of 2012 was illustrated using DGPS (Differential Global Positioning System, resolution < 0.6m) observation and drift experiment. Abrupt change in the shoreline was occurred in the latter part of June, 2012, this change was compared with that in June from 2009 to 2011. In the northern part of the beach, sand accumulated and it made beach extension and movement of the shoreline towards sea compared with that in June from 2009 to 2011. While on the other, in the southern part, the beach was eroded and it formed a steep slope around the southernmost of the beach. The shoreline in the southern part of the beach was shifted more towards land than that in the past. Change in the position of shoreline was higher in the northernmost and southernmost of the beach compared with those in the other parts. Drift in the southern part of the beach moved faster along the beach than that in the northern part of it.