The Journal of the Petrological Society of Korea (암석학회지)

The Petrological Society of Korea (한국암석학회)
권호 표지
DOI QR코드

DOI QR Code

Lahar flow simulation using Laharz_py program: Application for the Mt. Halla volcano, Jeju, Korea

Laharz_py 프로그램을 이용한 라하르 수치모의: 한라산 화산체에 적용

  • Yun, Sung-Hyo (Department of Earth Science Education, Pusan National University) ;
  • Chang, Cheolwoo (Department of Earth Science, Pusan National University)
  • Received : 2016.11.01
  • Accepted : 2016.11.16
  • Published : 2016.12.31
Download PDF
⟨ Previous Next ⟩

Abstract

Lahar, one of catastrophic events, has the potential to cause the loss of life and damage to infrastructure over inhabited areas. This study using Laharz_py program, was performed schematic prediction on the impact area of lahar hazards at the Mt. Halla volcano, Jeju island. In order to comprehensively address the impact of lahar for the Mt. Halla, two distinct parameters, H/L ratio and lahar volume, were selected to influence variable for Laharz_py simulation. It was carried out on the basis of numerical simulation by estimating a possible lahar volumes of 30,000, 50,000, 70,000, 100,000, 300,000, $500,000m^3$ according to H/L ratios (0.20, 0.22 and 0.25) was applied. Based on the numerical simulations, the area of the proximal hazard zone boundary is gradually decreased with increasing H/L ratio. The number of streams which affected by lahar tended to decrease with increasing H/L ratio. In the case of H/L ratio 0.20, three streams (Gwangryeong stream, Dogeun stream, Han stream) in the Jeju-si area and six streams (Gungsan stream, Hogeun stream, Seohong stream, Donghong stream, Bomok stream, Yeong stream-Hyodon stream) in the Seogwipo-si area are affected. In the case of H/L ratio 0.22, two streams (Gwangryeong stream and Han stream) in the Jeju-si area and five streams (Gungsan stream, Seohong stream, Donghong stream, Bomok stream, Yeong stream-Hyodon stream) in the Seogwipo-si area are affected. And in the case of H/L ratio 0.25, two streams (Gwangryeong stream and Han stream) in the Jeju-si area and one stream (Yeong stream-Hyodon stream) in the Seogwipo-si area are affected. The results of this study will be used as basic data to create a risk map for the direct damage that can be caused due to volcanic hazards arising from Mt. Halla.

라하르는 거주 지역 주변의 기반시설의 파괴와 인명 손실을 일으킬 가능성이 있는 격변적인 사건이다. 그러므로 라하르 위험지역의 영역 설정은 매우 중요한 작업이다. 본 연구에서는 Laharz_py 프로그램을 적용하여 한라산 화산체에서 발생 가능한 라하르 영향 지역에 대한 개략적인 예측을 수행하였다. 화산체의 지형구배(H/L비)와 라하르 부피를 시나리오의 영향 변수로 선정하였고, H/L비는 0.20, 0.22, 0.25로, 근위 위험지역 경계로부터 발원 가능한 하천의 하류 방향으로 발생 가능한 라하르 부피는 30,000, 50,000, 70,000, 100,000, 300,000, $500,000m^3$를 적용하여 시나리오를 작성하고, 이에 따라 모의를 진행하였다. 수치 모의 결과에 근거하면, H/L비가 증가함에 따라 근위 위험경계 지역의 면적은 점차 감소하였다. H/L비가 증가함에 따라 라하르 영향 하천의 개수가 줄어드는 경향을 보였다. H/L비 0.20인 경우 제주시 쪽의 3 하천(광령천, 도근천과 한천)과 서귀포시 쪽의 6 하천(궁산천-강정천, 호근천(완제천)), 서홍천(연외천), 동흥천, 보목천 그리고 영천-효돈천), H/L비 0.22인 경우 제주시 쪽의 2 하천(광령천과 한천)과 서귀포시 쪽의 5 하천(궁산천-강정천, 서홍천, 동흥천, 보목천 그리고 영천-효돈천), H/L비 0.25인 경우 제주시 쪽의 2 하천(광령천과 한천)과 서귀포시 쪽의 1 하천(영천-효돈천)이 라하르의 영향을 받는 하천이다. 본 연구의 결과는 한라산에서 발생하는 라하르로 인하여 야기될 수 있는 직접적인 화산재해 피해에 대한 위험등급도를 작성하는 기본 자료로 활용할 수 있을 것이다.

Keywords

References

  1. Brenna, M., Cronin, S.J., Smith, I.E.M., Maas, R., and Sohn, Y.K., 2012a, How small-volume basaltic magmatic systems develop: a case study from the Jeju Island Volcanic Field, Korea. Journal of Petrology, 53, 985-1018. https://doi.org/10.1093/petrology/egs007
  2. Brenna, M., Cronin, S.J., Smith, I.E.M., Sohn, Y.K., and Maas, R., 2012b, Spatio-temporal evolution of a dispersed magmatic system and its implications for volcanic growth, Jeju Island Volcanic Field, Korea. Lithos, 148, 337-352. https://doi.org/10.1016/j.lithos.2012.06.021
  3. Cheong, C.-S., Choi, M.S., Khim, B.K., Sohn, Y.K., and Kwon, S.-T., 2006, $^{230}Th/^{234}U$ dating of Holocene mollusk shells from Jeju Island, Korea, by multiple collectors inductively coupled plasma mass spectrometry. Geoscience Journal, 10, 67-74. https://doi.org/10.1007/BF02910333
  4. Cronin, S.J., Neall, V.E., Palmer, A.S., and Lecointre, J.A., 1997. Changes in Whangaehu river lahar characteristics during the 1995 eruption sequence, Ruapehu volcano, New Zealand. Journal of Volcanology and Geothermal Research. 76, 47-61. https://doi.org/10.1016/S0377-0273(96)00064-9
  5. Environmental Systems Research Institute, 2012, ArcGIS: Environmental Systems Research Institute Inc., Redlands, California.
  6. Griswold, J.P. and Iverson, R.M., 2008, Mobility statistics and automated hazard mapping for debris flows and rock avalanches(ver. 1.1, April 2014). U.S. Geological Survey Scientific Investigations Report, 2007-5276, 59p.
  7. Iverson, R.M., Schilling, S.P., and Vallance, J.W., 1998, Objective delineation of areas at risk from inundation by lahars. Geological Society of America Bulletin, 110, 972-984. https://doi.org/10.1130/0016-7606(1998)110<0972:ODOLIH>2.3.CO;2
  8. Jenson, S.K. and Domingue, J.O., 1988, Extracting topographic structure from digital elevation data for geographic information system analysis. Photogrammetric Engineering and Remote Sensing, 54, 1593-1600.
  9. Kim, H.J., Lee, K.H., Kim, S.W., Choi, E.K., Yun, S.H., and Kim, S.H., 2014, Scenario based analysis of lahar simulation of Mt. Baekdu using LAHARZ. International Area Studies Review, 18, 243-264. (in Korean) https://doi.org/10.18327/jias.2014.09.18.3.243
  10. Mothes, P.A., Hall, M.L., and Janda, R.J., 1998, The enormous Chillos Valley Lahar: An ash-flow generated debris flow from Cotopaxi Volcano, Ecuador. Bulletin of Volcanology, 59, 233-244. https://doi.org/10.1007/s004450050188
  11. Newhall, C.G., Hendley II, J.W., and Stauffer, P.H., 1997, Lahars of Mount Pinatubo, Philippines. U.S. Geological Survey Fact Sheet 114-97, http://pubs.usgs.gov/fs/1997/fs114-97/.
  12. Pierson, T.C. and Scott, K.M., 1985. Downstream dilution of a lahar: transition from debris flow to hyperconcentrated streamflow. Water Resources Research, 21, 1511-1524. https://doi.org/10.1029/WR021i010p01511
  13. Quinn, P., Beven, K., Chevallier, P., and Planchon, O., 1991, The prediction of hillslope flow paths for distributed hydrological modelling using digital terrain models. Hydrological Processes, 5, 59-79. https://doi.org/10.1002/hyp.3360050106
  14. Schilling, S.P., 2014, Laharz_py-GIS tools for automated mapping of lahar inundation hazard zones. U.S. Geological Survey Open-File Report 2014-1073, 78p., http://dx.doi.org/10.3133/ofr20141073.
  15. Scott, K.M., Vallance, J.W., and Pringle, P.T., 1995, Sedimentology, behavior, and hazards of debris flows at Mount Rainier, Washington. U.S. Geological Survey Professional Paper 1547, 56p.
  16. Sohn, Y.K., Park, J.B., Khim, B.K., Park, K.H., and Koh, G.W., 2002, Stratigraphy, petrochemistry and Quaternary depositional record of the Songaksan tuff ring, Jeju Island, Korea. Journal of Volcanology and Geothermal Research, 119, 1-20.
  17. Sohn, Y.K. and Park, K.H., 2004, Early-stage volcanism and sedimentation of Jeju Island revealed by the Sagye borehole, SW Jeju Island, Korea. Geosciences Journal, 8, 73-84. https://doi.org/10.1007/BF02910280
  18. Sohn, Y.K., Park, K.H., and Yoon, S.H., 2008, Primary versus secondary and subaerial versus submarine hydrovolcanic deposits in the subsurface of Jeju Island, Korea. Sedimentology, 55, 899-924. https://doi.org/10.1111/j.1365-3091.2007.00927.x
  19. Sohn, Y.K. and Yoon, S.H., 2010, Shallow-marine records of pyroclastic surges and fallouts over water in Jeju Island, Korea, and their stratigraphic implications. Geology, 38, 763-766. https://doi.org/10.1130/G30952.1
  20. Vallance, J.W., 2000, Lahars. In Encyclopedia of Volcanoes. (eds. Sigurdsson. H., Houghton, B.F., McNutt, S.R., Rymer, H., and Stix, J.) Academic Press, San Diego, 601-616.
  21. Vallance, J.W. and Iverson, R.M., 2015, Lahars and their deposits. In The Encyclopedia of Volcanoes, second edition (eds. Sigurdsson, H., Houghton, B., Rymer, H., Stix, J., McNutt, S.) Elsevier, Amsterdam, 649-664.
  22. Voight, B., 1990, The 1985 Nevado del Ruiz volcano catastrophe: Anatomy and retrospection. Journal of Volcanology and Geothermal Research, 44, 349-386. https://doi.org/10.1016/0377-0273(90)90027-D
  23. Witham, C., 2005, Volcanic disasters and incidents-a new database. Journal of Volcanology and Geothermal Research, 148, 191-233. https://doi.org/10.1016/j.jvolgeores.2005.04.017