Articles | Volume 11, issue 11
Nat. Hazards Earth Syst. Sci., 11, 3053–3062, 2011
https://doi.org/10.5194/nhess-11-3053-2011

Special issue: Documentation and monitoring of landslides and debris flows...

Nat. Hazards Earth Syst. Sci., 11, 3053–3062, 2011
https://doi.org/10.5194/nhess-11-3053-2011

Research article 18 Nov 2011

Research article | 18 Nov 2011

Application of simulation technique on debris flow hazard zone delineation: a case study in the Daniao tribe, Eastern Taiwan

M. P. Tsai1, Y. C. Hsu2, H. C. Li3, H. M. Shu4, and K. F. Liu5 M. P. Tsai et al.
  • 1Department of Water and Soil Conservation, National Chung Hsing University, Taichung, Taiwan
  • 2Department of Civil Engineering, National Taiwan University, Taipei, Taiwan
  • 3Socio-Economic System Division, National Science and Technology Center for Disaster Reduction, Taipei, Taiwan
  • 4Graduate Institute of Disaster Prevention on Hillslopes and Water Resources Engineering, National Pingtung University of Science and Technology, Pingtung, Taiwan
  • 5Department of Civil Engineering, National Taiwan University, Taipei, Taiwan

Abstract. Typhoon Morakot struck Taiwan in August 2009 and induced considerable disasters, including large-scale landslides and debris flows. One of these debris flows was experienced by the Daniao tribe in Taitung, Eastern Taiwan. The volume was in excess of 500 000 m3, which was substantially larger than the original design mitigation capacity. This study considered large-scale debris flow simulations in various volumes at the same area by using the DEBRIS-2D numerical program. The program uses the generalized Julien and Lan (1991) rheological model to simulate debris flows. In this paper, the sensitivity factor considered on the debris flow spreading is the amount of the debris flow initial volume. These simulated results in various amounts of debris flow initial volume demonstrated that maximal depths of debris flows were almost deposited in the same area, and also revealed that a 20% variation in estimating the amount of total volume at this particular site results in a 2.75% variation on the final front position. Because of the limited watershed terrain, the hazard zones of debris flows were not expanded. Therefore, the amount of the debris flow initial volume was not sensitive.

Download
Altmetrics