• Title/Summary/Keyword: proximal hazard zone boundary

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Prediction of Lahar Flow Inundation Areas Using LAHARZ_py Program: Application for the Mt. Baekdu Volcano (LAHARZ_py 프로그램을 이용한 라하르 범람지역의 예측: 백두산 화산에 적용)

  • Yun, Sung-Hyo;Chang, Cheolwoo
    • Economic and Environmental Geology
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    • v.50 no.4
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    • pp.277-286
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    • 2017
  • Mt. Baekdu which located the border of North Korea and China, is known as a potentially active volcano in a typical mountainous terrain. A lahar on the volcanic area is one of the important hazard that can cause the loss of life and property damage. In order to comprehensively address the impact of lahar hazard at Mt. Baekdu, we simulated lahar inundation area using Laharz_py. We assumed 750 m of additional elevation for DEM to draw proximal hazard zone boundary (PHZB) of Mt. Baekdu that H/L ratio are selected 0.10. And lahar volumes for simulation were estimated to $1{\times}10^6$, $5{\times}10^6$, $1{\times}10^7$, $5{\times}10^7$, $1{\times}10^8$, $5{\times}10^8$, $1{\times}10^9m^3$, respectively. In the results, 15 streams are located near a proximal hazard zone boundary, Amnok (Yalu) river (south), Toudaosonghua river, Jinjiang river and Huapi river (west-southwest), Songjiang river, Xiaosha river, Caozi river and Sandaosongjian river (west-northwest), Toudaobai river, Erdaobai river and Sandabai river (north), Wudaobai river-1, -2, -3 (northeast) and Duman (Tumen) river (east). The results of this study can be used as basic data to make a hazard map for reduce the damage that can be caused by volcanic hazards occurred on Mt. Baekdu.

Lahar Simulation on Ulleung Island Using Laharz_py Program (Laharz_py 프로그램을 이용한 울릉도 라하르 수치모의)

  • Chang, Cheolwoo;Yun, Sung-Hyo
    • The Journal of the Petrological Society of Korea
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    • v.26 no.1
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    • pp.55-62
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    • 2017
  • A Lahar on the volcanic area is one of the important hazard that can cause the loss of life and property damage. In order to estimate lahar hazard area at Ulleung Island, we simulated lahar inundation area using Laharz_py. We assumed 400 m of additional elevation for DEM to draw proximal hazard zone of Ulleung Island that H/L ratio were selected 0.45 and 0.5. And lahar volumes for simulation were estimated to 30,000, 50,000, 70,000, $100,000m^3$, respectively. In the results, 5 streams are located near a proximal hazard zone, Jeodong (east), Sadong and Okchon (southeast), Namyang (southwest), and Chusan (north), Nari basin is also considered that has a possibility of lahar during downpour. The results of this study can be used as basic data to make a hazard map for reduce the damage that can be caused by volcanic hazards occurred on Ulleung Island.

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;Chang, Cheolwoo
    • The Journal of the Petrological Society of Korea
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    • v.25 no.4
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    • pp.361-372
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    • 2016
  • 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.