Debris-flow events and their mitigations in the Qianghuangkeng stream, Tainan, Taiwan

Chyan Deng Jan, Kuo Hsun Tseng, Ji Shang Wang, Yu Chao Hsu

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Typhoon Morakot lashed Taiwan with about 2800mm of rain over August 7~10, 2009, and caused catastrophic sediment hazards in the southern and central Taiwan such as landslides and debris flow. The Qianghuangkeng stream watershed is located at Nanhua Township in southern Taiwan where has been channelized which was a 3m width and 5m depth concrete channel about 400m and became more meandering for avoiding pass through the private lands to prevent debris flow inundation after Typhoon Kalmaegi in 2008, but debris flow still occurred during typhoon Morakot and damaged 15 buildings, therefore we need to know the performance of the countermeasure. Base on field investigation and hydraulic numerical model FLO-2D (FLO-2D Software, Inc) simulations, we analyzed the inundation area and depth with channelization countermeasure and natural channel during typhoon Morakot which accumulative rainfall of return period was over 200 years. We also discussed the performance of the countermeasure under designation standard that return period was 50 years. The results show that the community nearby stream was inundated by debris flow during typhoon Morakot no matter channelization countermeasure or natural channel and the inundation area and maximum depth were getting close. In case the return period is 50 years, the inundated area and maximum depth of natural channel are larger than channelization countermeasure. It reveals that the countermeasure is effective against debris flow under the return period of designation, but extreme rainfall such as typhoon Morakot.

Original languageEnglish
Title of host publication34th IAHR Congress 2011 - Balance and Uncertainty
Subtitle of host publicationWater in a Changing World, Incorporating the 33rd Hydrology and Water Resources Symposium and the 10th Conference on Hydraulics in Water Engineering
PublisherInternational Association for Hydro-Environment Engineering and Research (IAHR)
Pages210-217
Number of pages8
ISBN (Electronic)9780858258686
Publication statusPublished - 2011 Jan 1
Event34th IAHR Congress 2011 - Balance and Uncertainty: Water in a Changing World, Incorporating the 33rd Hydrology and Water Resources Symposium and the 10th Conference on Hydraulics in Water Engineering - Brisbane, Australia
Duration: 2011 Jun 262011 Jul 1

Publication series

Name34th IAHR Congress 2011 - Balance and Uncertainty: Water in a Changing World, Incorporating the 33rd Hydrology and Water Resources Symposium and the 10th Conference on Hydraulics in Water Engineering

Conference

Conference34th IAHR Congress 2011 - Balance and Uncertainty: Water in a Changing World, Incorporating the 33rd Hydrology and Water Resources Symposium and the 10th Conference on Hydraulics in Water Engineering
CountryAustralia
CityBrisbane
Period11-06-2611-07-01

All Science Journal Classification (ASJC) codes

  • Engineering (miscellaneous)
  • Water Science and Technology
  • Environmental Science (miscellaneous)

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  • Cite this

    Jan, C. D., Tseng, K. H., Wang, J. S., & Hsu, Y. C. (2011). Debris-flow events and their mitigations in the Qianghuangkeng stream, Tainan, Taiwan. In 34th IAHR Congress 2011 - Balance and Uncertainty: Water in a Changing World, Incorporating the 33rd Hydrology and Water Resources Symposium and the 10th Conference on Hydraulics in Water Engineering (pp. 210-217). (34th IAHR Congress 2011 - Balance and Uncertainty: Water in a Changing World, Incorporating the 33rd Hydrology and Water Resources Symposium and the 10th Conference on Hydraulics in Water Engineering). International Association for Hydro-Environment Engineering and Research (IAHR).