한국수자원학회논문집 (Journal of Korea Water Resources Association)

  • 제53권8호
  • /
  • Pages.627-636
  • /
  • 2020
  • /
  • 2799-8746(pISSN)
  • /
  • 2799-8754(eISSN)
한국수자원학회 (Korea Water Resources Association)
권호 표지
DOI QR코드

DOI QR Code

도심지 급경사지에서 토석류 범람 특성 및 사방댐 기능

Debris flow characteristics and sabo dam function in urban steep slopes

  • 김연중 (인제대학교 토목도시공학부) ;
  • 김태우 (인제대학교 토목도시공학부) ;
  • 김동겸 (인제대학교 토목도시공학부) ;
  • 윤종성 (인제대학교 토목도시공학부)
  • Kim, Yeonjoong (Department of Civil and Urban Engineering, Inje University) ;
  • Kim, Taewoo (Department of Civil and Urban Engineering, Inje University) ;
  • Kim, Dongkyum (Department of Civil and Urban Engineering, Inje University) ;
  • Yoon, Jongsung (Department of Civil and Urban Engineering, Inje University)
  • 투고 : 2020.05.12
  • 심사 : 2020.07.13
  • 발행 : 2020.08.31
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

과거의 토석류 재해는 도시로부터 멀리 떨어진 산지지형에서 주로 발생하여 다른 자연재해 보다 비교적 피해가 적은 재해로 저평가 되었다. 하지만 도시화가 진행됨에 따라 도심속 산지지형에 많은 주거지 및 주요 시설물 등이 건설되면서 많은 환경적 변화와 기후변화에 따른 강우량의 증가로 토사재해의 발생 빈도가 꾸준히 증가 하고 있어 토석류에 대한 위험 리스크가 고조되고 있다. 특히 급경사지로 지정된 지역에서 토석류 범람 특성 및 저감대책에 관한 연구는 아직 미비하다. 따라서 우리나라 환경에 적합한 독자적인 방재 기술을 확보하기 위한 연구와 여러 방재 정보의 업데이트 및 개량이 요구되며 우리나라 지형 특성을 고려할 수 있는 독자적인 기술이 필요하다. 본 연구에서는 우리나라 급경사지로 지정된 지역을 대상으로 방재성능목표에 따른 토사 유출량을 산정하고 그에 따른 독자적인 모델을 개발하여 토석류 영향평가와 피해저감에 탁월한 사방댐의 기능 평가를 목적으로 한다. 사방댐 평가를 위해 개발한 2차원 토석류 모델의 신뢰성 확보를 위해 수리모형실험과의 비교 검증 결과 잘 일치하는 것으로 나타났으며 이 결과로부터 모델의 신뢰성을 확인하였다. 또한, 급경사지 주변의 지역적 특징을 고려하기 위해 평면 2차원 토석류 모델을 구축하여 직접 피해지역에 도달하는 토석류의 흐름 특성을 분석하였고, 피해저감을 위해 설치한 사방댐의 제원(높이) 및 설치장소에 따라 토석류가 하류로 전달되는 흐름 특성을 분석하였다. 특히 사방댐 설치장소가 토석류의 흐름이 발생하는 약 20° 이상의 지역에서는 사방댐의 기능이 현저히 떨어지는 것을 확인하였다.

Debris flow disasters primarily occur in mountainous terrains far from cities. As such, they have been underestimated to cause relatively less damage compared with other natural disasters. However, owing to urbanization, several residential areas and major facilities have been built in mountainous regions, and the frequency of debris flow disasters is steadily increasing owing to the increase in rainfall with environmental and climate changes. Thus, the risk of debris flow is on the rise. However, only a few studies have explored the characteristics of flooding and reduction measures for debris flow in areas designated as steep slopes. In this regard, it is necessary to conduct research on securing independent disaster prevention technology, suitable for the environment in South Korea and reflective of the topographical characteristics thereof, and update and improve disaster prevention information. Accordingly, this study aimed to calculate the amount of debris flow, depending on disaster prevention performance targets for regions designated as steep slopes in South Korea, and develop an independent model to not only evaluate the impact of debris flow but also identify debris barriers that are optimal for mitigating damage. To validate the reliability of the two-dimensional debris flow model developed for the evaluation of debris barriers, the model's performance was compared with that of the hydraulic model. Furthermore, a 2-D debris model was constructed in consideration of the regional characteristics around the steep slopes to analyze the flow characteristics of the debris that directly reaches the damaged area. The flow characteristics of the debris delivered downstream were further analyzed, depending on the specifications (height) and installation locations of the debris barriers employed to reduce the damage. The experimental results showed that the reliability of the developed model is satisfactory; further, this study confirmed significant performance degradation of debris barriers in areas where the barriers were installed at a slope of 20° or more, which is the slope at which debris flows occur.

키워드

참고문헌

  1. Choi, S-K., Lee, H-M., Jeong, H-B., Kim, J-H., and Kwon, T-H. (2015). "Effect of arrangement of slit-type barriers on debris flow behavior: Laboratory-scaled experiment." Journal of the Korean Society of Hazard Mitigation. Vol. 15, No. 3, pp. 223-228. https://doi.org/10.9798/KOSHAM.2015.15.3.223
  2. Egashira, S., Honda, N., and Itoh, T. (2001). "Experimental study on the entrainment of bed material into debris flow." Physics and Chemistry of the Earth (C), Vol. 26, No. 9, pp. 645-650. https://doi.org/10.1016/S1464-1895(01)00114-4
  3. Honda, N., and Egashira, S. (1997). "Prediction of debris flow characteristics in mountainous torrents." Proceedings of First Conference on Debris-Flow Hazards Mitigation: Mechanics, Prediction, and Assessment, ASCE, C.A., pp. 707-716.
  4. Kim, D-K. (2020). Study on hydraulic characteristics of sabo dam and application for real field by numerical simulation of debris flow. Ph. D. dissertation, University of Inje, pp. 83-119.
  5. Kim, G-S., Ryu, H-S. and Kim, S-H. (2019). "Evaluation of coastal sediment budget on east coast Maeongbang beach by wave changes." Journal of Ocean Engineering and Technology, Vol. 33, No. 6, pp. 564-572. https://doi.org/10.26748/KSOE.2019.099
  6. Kim, S., Paik, J., and Kim, K-S. (2013). "Run-out modeling of debris flows in Mt. Umyeon using FLO-2D." Journal of the Korean Society of Civil Engineers, Vol. 33, No. 3, pp. 965-974. https://doi.org/10.12652/Ksce.2013.33.3.965
  7. Kim, Y-J., Yoon, J-S., Tanaka, K., and Hur, D-S. (2015). "Prediction of a debris flow flooding caused by probable maximum precipitation." Journal of Korea Water Resour. Assoc, Vol. 48, No. 2, pp. 115-126. https://doi.org/10.3741/JKWRA.2015.48.2.115
  8. Korea Forest Service (KFS) (2017). 17yr+Vulnerability to landslides+ designation+present.xlsx, accessed 1 October 2019, .
  9. Nakagawa, H., Takahashi, T., Satofuka, Y., and Kawaike, K. (2001). "Sediment disasters caused by the heavy rainfall in the Camuri Grande River basin, Venezuela, 1999." Annuals of the Disaster Prevention Research Institute, Kyuto University, No.44, No. B-2, pp.207-228 (in Japanese).
  10. National Institute for Land and Infrastructure Management (NILIM) (2016). Manual of technical standard for establishing sabo master plan for debris flow and driftwood. Technical note of national institute for land infrastructure management, No. 364. Japan, pp. 25-32.
  11. Osanai, N., Mizuno, H., and Mizuyama, T. (2010). "Design standard of control structures aginst debris flow in Japan." Journal of Disaster Research, Vol. 5, No. 3, pp. 307-314. https://doi.org/10.20965/jdr.2010.p0307
  12. Satofuka, Y., and Mizuyama, T. (2005). "Numerical simulation on a debris flow in a mountainous river with a sabo dam." Journal of the Japan Society of Erosion Control Engineering, Vol. 58, No. 1, pp. 14-19 (in Japanese with English Abstract).
  13. Shrestha, B.B. (2009). "Study on mitigation measures against debris flow disasters with driftwood." Ph. D. dissertation, University of Kyoto, Kyoto, Japan.
  14. Takahashi, T., Nakagawa, H., Harada, T., and Yamashiki, Y. (1992). "Routing debris flows with particle segregation." Journal of Hydraulic Engineering, ASCE, Vol. 118, No. 11, pp. 1490-1507. https://doi.org/10.1061/(ASCE)0733-9429(1992)118:11(1490)
  15. Takahashi, T., Nakagawa, H., Satofuka, Y., and Kawaike, K. (2001a). "Flood and sediment disasters triggered by 1999 rainfall in Venezuela; A river restoration plan for an alluvial fan." Journal of Natural Disaster Science, Vol. 23, No. 2, pp. 65-82.
  16. Takahashi, T., Nakagawa, H., Satofuka, Y. and Wang, H. (2001b). "Stochastic model of blocking for a grid-type dam by large boulders in a debris flow." Annual Journal of Hydraulic Engineering, JSCE, Vol. 45, pp. 703-708 (in Japanese). https://doi.org/10.2208/prohe.45.703