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Research Article

Susceptibility Analysis of Access Trails to Debris Flows at 12 Waterfalls in Mt. Naeyeon Using a Random Walk Model

랜덤워크 모델을 활용한 내연산 12폭포 탐방로의 토석류 취약성 분석

Yunsu Lee1
,
Jaeho Lee2
,
Junghae Choi3*
이 윤수1
,
이 재호2
,
최 정해3*
1Head of Geopark Team, Gyeongbuk Donghaean Geopark Agency
2Master’s Student, Department of Geology, Kyungpook National University
3Professor, Department of Earth Science Education, Kyungpook National University
1경북동해안지질공원사무국 팀장
2경북대학교 지질학과 석사과정
3경북대학교 지구과학교육과 교수
*Corresponding Author
31 March 2025. pp. 107-117
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Abstract

Geoparks have been attracting increasing international interest by conserving geologically valuable heritage through education and tourism while contributing to local economies. The 12 Waterfalls of Naeyeonsan, located in the Gyeongbuk Donghaean Geopark, are known for diverse geological formations and picturesque landscapes. At the same time, the trails in Naeyeonsan are exposed to debris flows due to their steep slopes and cliffs. However, previous investigations have been limited by the lack of assessment of debris-flow risk on trails and the establishment of trail management systems. Therefore, the aim of the present study is to predict debris-flow runout along the 12 Waterfalls trail of Naeyeonsan by applying a simplified version of the dfwalk model. In this study, initial landslide points were delineated by identifying Grade 1 zone on the landslide hazard map of the Korea Forest Service. The initial debris volume was determined as the product of the mapped Grade 1 zone, and the soil depth was derived from the Z-model. To delineate the travel path and dispersion extent of debris flows, we applied the simple flow routing method and performed 10,000 monte carlo simulations. Based on these simulations, we subsequently estimated debris flow trajectory probabilities. As a result, it was shown that approximately 10% of the roughly 8.5 km Naeyeonsan Course 2 trail is susceptible to debris flows. The analysis indicates that trail sections at seven waterfalls are highly susceptible, while trail sections at five waterfalls have relatively low susceptibility. These findings are expected to serve as fundamental data for the identification of debris-flow susceptible areas within geoparks and for establishing evacuation routes in advance.

Keywords
geopark
12 Waterfalls of Naeyeonsan
random walk
debris flow

지질공원은 지질학적으로 가치가 있는 지질유산을 교육 및 관광을 통해 자발적인 보전과 지역 경제 발전에 기여하는 프로그램으로서, 국내외 중요성과 관심이 점차 증가하고 있다. 경북 동해안 지질공원 중 하나인 내연산 12폭포는 다양한 지질구조의 형성과 아름다운 경관을 제공하는 관광지이지만 주요 탐방로의 주변이 급경사지 및 절벽 등으로 토석류의 위험에 노출되어 있다. 하지만 탐방로에 대한 토석류와 같은 재해위험성 평가 및 탐방로 관리 체계 수립에 대한 연구는 미미한 실정이다. 따라서 본 연구는 내연산 12폭포 탐방로에 대한 토석류 확산범위 예측을 하기 위해 단순화시킨 dfwalk 모델을 적용하였다. 초기 토사 붕괴지점은 산림청에서 제공하는 산사태 위험지도 1등급 구역을 활용하였으며, 초기 토사붕괴량은 산사태 위험지도의 1등급 면적과 Z-model을 통해 도출된 토심의 곱으로 산정하였다. 이후 토석류의 이동확률 및 확산범위를 파악하기 위해 simple flow routing 기법을 적용하고 10,000회의 몬테카를로 시뮬레이션을 수행하였다. 분석 결과, 내연산 2코스 탐방로 약 8.5 km 중 약 10%에 해당하는 부분이 토석류에 취약한 것으로 예측되었다. 또한 내연산 12폭포 중 7개의 폭포구간이 토석류에 대한 취약성이 높게 나타났으며, 5개 구간은 토석류의 영향이 거의 미미한 것으로 나타났다. 이러한 결과는 지질공원 내 토석류 위험구간을 사전에 파악하고 대피로를 사전에 설정함에 있어 기초자료로서 활용될 수 있을 것으로 기대된다.

키워드
지질공원
내연산 12폭포
랜덤워크
토석류
References
1

Corominas, J., 1996, The angle of reach as a mobility index for small and large landslides, Canadian Geotechnical Journal, 33(2), 260-271.

10.1139/t96-005
2

Cruden, D.M., Varnes, D.J., 1996, Landslide types and processes, In: Turner, A.K., Schuster, R.L. (Eds.), Landslides: Investigation and Mitigation, Transportation Research Board, Special Report 247, 36-75.

3

Gamma, P., 1999, dfwalk - A debris flow simulation program for hazard zoning, Ph.D. Thesis, University of Berne, 144p (in German).

4

Hürlimann, M., Rickenmann, D., Medina, V., Bateman, A., 2008, Evaluation of approaches to calculate debris-flow parameters for hazard assessment, Engineering Geology, 102(3-4), 152-163.

10.1016/j.enggeo.2008.03.012
5

Jackson, L., Hungr, O., Gardner, J., MacKay, C., 1989, Cathedral Mountain debris flows, Canada, Bulletin of the International Association of Engineering Geology, 40(1), 35-54.

10.1007/BF02590340
6

Jang, Y.D., 2018, Detailed academic survey report for the designation of the Donghaean global geopark, Gyeongbuk Donghaean Geopark, 212-234 (in Korean).

7

Jeon, Y.M., Koh, J.G., Ki, J.S., Lee, S.J., 2016, A case study on the geotrail revitalization in the Jeju Island Geopark, Journal of the Geological Society of Korea, 52(5), 527-538 (in Korean with English abstract).

10.14770/jgsk.2016.52.5.527
8

Ju, S.O., Woo, K.S., 2016, National Geoparks in Korea: Current status and their implementation, Journal of the Geological Society of Korea, 52(5), 587-607 (in Korean with English abstract).

10.14770/jgsk.2016.52.5.587
9

Komu, M.P., Nefeslioglu, H.A., Gokceoglu, C., 2023, A review of the prediction methods for landslide runout, Proceedings of the 4th International Electronic Conference on Geosciences, Basel, 87(1), 3.

10.3390/IECG2022-14604
10

Kwon, D.H., 2011, Development of expansive contents for Jeju-do Geopark -Focus on Sanbangsan and Yongmuri Beach-, Journal of the Korean Geomorphological Association, 18(3), 1-10 (in Korean with English abstract).

11

Rickenmann, D., 1999, Empirical relationships for debris flows, Natural Hazards, 19(1), 47-77.

10.1023/A:1008064220727
12

Rickenmann, D., Scheidl, C., 2013, Debris-flow runout and deposition on the fan, In: Schneuwly-Bollschweiler, M., Stoffel, M., Rudolf-Miklau, F. (Eds.), Dating Torrential Processes on Fans and Cones: Methods and Their Application for Hazard and Risk Assessment, Springer, 75-93.

10.1007/978-94-007-4336-6_5
13

Saulnier, G.M., Beven, K., Obled, C., 1997, Including spatially variable effective soil depths in TOPMODEL, Journal of Hydrology, 202(1-4), 158-172.

10.1016/S0022-1694(97)00059-0
14

Song, Y.S., Lee, M.S., 2023, A random walk model for estimating debris flow damage range, The Journal of Engineering Geology, 33(1), 201-211 (in Korean with English abstract).

10.9720/kseg.2023.1.201
15

UNESCO, 2024, UNESCO Global Geoparks, Retrieved from https://www.unesco.org/en/iggp/geoparks/about.

16

Varnes, D.J., 1978, Slope movement types and processes, In: Schuster, R.L., Kizek, R.J. (Eds.), Landslides: Analysis and Control, US National Academy of Sciences, Transportation Research Board, Special Report 176, 11-33.

Information
  • Publisher :Korean Society of Engineering Geology
  • Publisher(Ko) :대한지질공학회
  • Journal Title :The Journal of Engineering Geology
  • Journal Title(Ko) :지질공학
  • Volume : 35
  • No :1
  • Pages :107-117
  • Received Date : 2025-02-25
  • Revised Date : 2025-03-24
  • Accepted Date : 2025-03-26
  • DOI :https://doi.org/10.9720/kseg.2025.1.107
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