DOI QR코드

DOI QR Code

충남 태안군 신두리 대조차 해빈에 나타나는 다중사주의 계절별 지형변화 특성

Seasonal Morphodynamic Changes of Multiple Sand Bars in Sinduri Macrotidal Beach, Taean, Chungnam

  • 장태수 (전남대학교 지구환경과학부) ;
  • 이영윤 (지마텍(주)) ;
  • 윤현호 (한국지질자원연구원 제4기환경연구센터) ;
  • 도기덕 (국립한국해양대학교 해양공학과)
  • Tae Soo Chang (Faculty of Earth and Environmental Sciences, Chonnam National University) ;
  • Young Yun Lee (GEMATEK corporation) ;
  • Hyun Ho Yoon (Quaternary Environment Research Center, Korea Institute of Geosciences and Mineral Resources) ;
  • Kideok Do (Department of Ocean Engineering, National Korea Maritime and Ocean University)
  • 투고 : 2024.06.17
  • 심사 : 2024.06.28
  • 발행 : 2024.06.30

초록

태안군 신두리 대조차 해빈에 나타나는 다중사주의 여름철 출현과 겨울철 사라짐 패턴을 조사하고 이들이 어떻게 겨울철에 소멸하고, 여름철에 다시 생성되는지를 토의하였다. 계절에 따른 다중사주의 지형변화는 VRS-GPS 시스템을 이용하여 지난 4년 동안 주기적으로 해빈 측선측량을 실시하여 파악하였다. 사주의 구성퇴적물을 알아보고자 계절에 따른 표층퇴적물을 채취하여 입도분석을 수행하였다. 추가적으로 유속자료를 확보하기 위해, TIDOS 조류관측시스템을 여름과 겨울에 각각 설치하여 얻었다. 신두리 해빈은 급경사의 상부 사빈면과 완만한 하부 조간대 지역으로 구분된다. 사빈면은 범(berm)의 발달이 미약하고, beach cusp가 나타나지 않아 매우 단조로운 지형을 갖고 있다. 조간대 지역은 폭이 400 m로서 넓고 2- 5개의 사주열이 나타난다. 사빈의 구성 퇴적물 평균입도는 2.0-2.75 phi 범위로 세립사에 해당하며, 육지방향으로 갈수록 조립해지는 경향을 띤다. 반복적 측선측량 결과, 신두리 해빈은 여름철 다중사주가 최대 5열까지 발달하는 해빈 단면을, 반면 겨울철에는 사주의 발달이 없는 편평한 해빈 단면을 갖는다. 겨울철 다중사주의 사라짐은 겨울의 강한 파랑으로 사주의 마루가 침식되고 골에 퇴적되는, 깎고 채움의 결과로 해석된다. 여름철 다중사주의 생성은 고조 시 정지상태에서 정상파 운동에 의해 생성되기보다는 조위면의 이동과 평상 파랑이 결합된 break-point 기작으로 설명된다. 평균해수면 근처의 사주가 가장 크고 뚜렷함, 육지방향으로 갈수록 사주의 진폭이 감소함, 다중사주 진폭의 불규칙함, 사주의 강한 비대칭, 그리고 육지방향으로 10-30 m 사주의 이동은 break-point 기작을 뒷받침한다.

This study aimed to investigate the seasonal patterns of multiple bar formation in summer and flattening in winter on the macrotidal Sinduri beach in Taean, and to understand the processes their formation and subsequent flattening. Beach profiling has been conducted regularly over the last four years using a VRS-GPS system. Surface sediment samples were collected seasonally along the transectline, and grain size analyses were performed. Tidal current data were acquired using a TIDOS current observation system during both winter and summer. The Sinduri macrotidal beach consists of two geomorphic units: an upper high-gradient beach face and a lower gentler sloped intertidal zone. High berms and beach cusps did not develop on this beach face. The approximately 400-m-wide intertidal zone comprises distinct 2-5 lines of multiple bars. Mean grain sizes of sand bars range from 2.0 to 2.75 phi, corresponding to fine sands. Mean sizes show shoreward coarsening trend. Regular beach-profiling survey revealed that the summer profile has a multi-barred morphology with a maximum of five bar lines, whereas, the winter profile has a non-barred, flat morphology. The non-barred winter profiles likely result from flattening by scour-and-fill processes during winter. The growth of multiple bars in summer is interpreted to be formed by a break-point mechanism associated with moderate waves and the translation of tide levels, rather than the standing wave hypothesis, which is stationary at high tide. The break-point hypothesis for multi-bars is supported by the presence of the largest bar at mean sea-level, shorter bar spacing toward the shore, irregular bar spacing, strong asymmetry of bars, and the 10-30 m shoreward migration of multi-bars.

키워드

과제정보

이 논문은 전남대학교 학술연구비(과제번호: 2022-2612) 지원을 받아 수행되었습니다. 현장조사와 그림 작업을 도와준 전남대 지구환경과학부 해양지질·퇴적학 실험실 학생들에게 감사드립니다. 심사과정에서 건설적인 비평과 조언은 큰 도움이 되었습니다. 익명의 심사위원께 감사드립니다.

참고문헌

  1. Aagaard, T., Kroon, A., Hughes, M.G., and Greenwood, B., 2008, Field observations of nearshore bar formation. Earth Surface Processes and Landforms, 33, 1021-1032. 
  2. Bascom, W.N., 1953, Characteristics of natural beaches. Proceedings of the 4th Coastal Engineering Conference, American Society of Civil Engineers, 163-180. 
  3. Blott, S.J. and Pye, K., 2001, GRADISTAT: A grain size distribution and statistics package for the analysis of unconsolidated sediments. Earth Surface Processes and Landforms, 26, 1237-1248. 
  4. Blott, S.J., 2010, GRADISTAT version 8.0: A grain size distribution and statistics package for the analysis of unconsolidated sediments by sieving or laser granulometer. Instructions on the use of the GRADISTAT program, 5 p. 
  5. Carver, R.E., 1971, Procedures in Sedimentary Petrology. Wiley-Interscience, New York, 652 p. 
  6. Davies, J.L., 1964, A morphologenic approach to world shorelines. Zeitschrift fur Geomorphologie, 8, 127-142. 
  7. Flemming, B.W., 2005, Tidal environments. In: Schwartz, M. (ed.), Encyclopedia of Coastal Science. Springer, Berlin, 1180-1185. 
  8. Folk, R.L. and Ward, W.C., 1957, Brazos River bar: A study in the significance of grain size parameters. Journal of Sedimentary Petrology, 27, 3-26. 
  9. Gresswell, R.K., 1937, The geomorphology of the southwest Lincolnshire coastaline. Geographical Journal, 90, 335-349. 
  10. Hayes, M.O. and Michel, J., 2011, A Coast to Explore. Coastal Geology and Ecology of Central California. Pandion Books, South Carolina, 338 p. 
  11. Holman, R.A. and Sallenger, A.H., 1993, Sand bar formation: a discussion of the Duck experiment series. Journal of Coastal Research, Speical Issue, No. 15, 76-92. 
  12. Johnson, D.W., 1949, Scale effects in hydraulic models involving wave motion. Transactions American Geophysical Union, 30, 517-525. 
  13. Jun, H., Chang, T.S., and Do, K., 2021, Field observation and numerical modelling for morphological response in the macro-tidal beach. Journal of Coastal Disaster Prevention, 8, 55-68. (in Korean) 
  14. Jung, P.M., Choi, K.H., and Kim, Y., 2012, Seasaonl changes in coastal dunes and its implication, Sohwangri, in Chungnam Province. Journal of the Korean Geomorphological Association, 19, 109-122. (in Korean) 
  15. Kahng, T.G., 2001, The Coastal Sand dune development at South Choongchung Province. Ph.D. thesis, Korea University, 141 p. (in Korean) 
  16. Kim, S.-R., Woo, H.-J., Lee, Y.-K., Jeong, K.-S., Je, J.-G., Park, G.-T., Jung, B.-H., and Cho, J-H., 2002, Seabottom sediments and seafloor acoustic image by side scan sonar on Sindu-ri offshore. Journal of Korean Earth Science Society, 23, 707-721. (in Korean) 
  17. King, C.A.M. and Williams, W.W., 1949, The formation and movement of sand bars by wave action. Geographical Journal, 113, 70-85. 
  18. King, C.A.M., 1972, Beaches and Coasts. Edward Arnold, London, 570 p. 
  19. Komar, P.D., 1998, Beach Processes and Sedimentation. Prentice Hall, New Jersey, 544 p. 
  20. Larson, M., Kraus, N.C., Sunamura, T., 1988, Beach profile change: morphology, transport rate, and numerical simulation. Proceedings of the 21st Coastal Engineering Conference, American Society of Civil Engineers, 1295-1309. 
  21. Masselink, G. and Anthony, E., 2001, Location and size of intertidal bars on macrotidal ridge and runnel beaches. Earth Surface Processes and Landforms, 26, 759-774. 
  22. Masselink, G. and Short, A.D., 1993, The effect of tide range on beach morphodynamics and morphology: a conceptual beach model. Journal of Coastal Research, 9, 785-800. 
  23. Masselink, G., Hughes, M., and Knight, J., 2011, Introduction to Coastal Processes & Geomorphology. Hodder Education, London, 416 p. 
  24. Masselink, G., Kroon, A., and Davidson-Arnott, R.G., 2006, Morphodynamics of intertidal bars in wave-dominated coastal settings- a review. Geomorphology, 73, 33-49. 
  25. Scott, T., Masselink, G., and Russell, P., 2011, Morphodynamic characteristics and classification of beaches in England and Wales. Marine Geology, 286, 1-20. 
  26. Senechal, N., Gouriou, T., Castelle, B., Parisot, J.-P., Capo, S., Bujan, S., and Howa, H., 2009, Morphodynamic response of a meso- to macro-tidal intermediate beach based on a long-term data set. Geomorphology, 107, 263-274. 
  27. Shepard, F.P., 1950, Beach Cycles in Southern California. U.S.Army Corps of Engineers, Beach Erosion Board, Technical Memo No. 20. 
  28. Shin, Y.H. and Seo, J.C., 2014, Sediment characteristics of the beach and subtidal zone in Shindu marine protected area. Journal of the Korean Geographical Society, 49, 812-832. (in Korean) 
  29. Short, A.D. and Woodroffe, C.D., 2009, The Coast of Australia. Cambridge University Press, New York, 288 p.
  30. Short, A.D., 2006, Australian beach systems-nature and distribution. Journal of Coastal Research, 22, 11-27. 
  31. van Houwelingen, S., Masselink, G., and Bullard, J., 2008, Dynamics of multiple intertidal bars over semidiurnal and lunar tidal cycle, North Lincolnshire, England. Earth Surface Processes and Landforms, 33, 1473-1490. 
  32. Vaucher, R., Pittet, B., Passot, S., Grandjean, P., Humbert, T., and Allemand, P., 2018, Bedforms in a tidally modulated ridge and runnel shoreface (Berck-Plage; North France): implications for the geological record. BSGF Earth Science Bulletin, 189, 5. 
  33. Yoon, H.H., 2011, Sedimentary characteristics of the Sinduri intertidal flat, Taean area, western coast of Korea. Master thesis, Chonnam National University, 97 p. (in Korean) 
  34. Yoon, H.H. and Chun, S.S., 2019, Rapid shift of surface sedimentary facies and its depositional mechanism in the macrotidal wave-dominated Sinduri Bay, west coast of Korea. Journal of the Geological Society of Korea, 55, 257-276. (in Korean)