Skip to main content

Advertisement

Log in

Experimental study on the mitigation effects of deflection walls on debris flow hazards at the confluence of tributary and main river

  • Original Paper
  • Published:
Bulletin of Engineering Geology and the Environment Aims and scope Submit manuscript

Abstract

To mitigate debris flow hazards in correspondence of a stream confluence, deflection walls can be built to modify the confluence angle and reduce the negative blockage of the main channel. However, the effectiveness of such deflection walls has yet been fully investigated. Therefore, we conducted two series of flume experiments with and without streamflow in the main channel to investigate how deflection walls influence debris flow deposition and flow depth variations at the confluence. The results indicate that the deflection angle controls the magnitude and shape of the deposit at the confluence. After the initial sediment pulse into the main channel, part of the sediment was transported downstream and the sediment deposits at the confluence were partially eroded and reshaped. The efficiency at which sediment is being trapped on the fan increases linearly with the increase in deflection angle. Overall, with the change of confluence angle from 90° (i.e., perpendicular to the main channel) to both larger and smaller angles, both the water wave height on the opposite bank and the upstream backwater height decreased, and the obstructed ratio (width ratio) and affected area of deposit at the confluence decreased. Our results indicate that deflection walls can effectively mitigate debris flow hazards at a stream confluence.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12

Similar content being viewed by others

References

Download references

Acknowledgements

This research was supported by the National Natural Science Foundation of China (grant no. U20A20111) and the National Key Technology Research and Development Program of China (grant no. 2018YFC1508605). HZ and JW developed the idea and designed the experiment. JW, Jiajun Wu, and Rui Jiang conducted the experiment. JW, MAH, and MS analyzed the data and wrote the manuscript. All of the authors discussed and revised the paper. The visit to the University of British Columbia, Canada for JW was supported by the China Scholarship Council (file no. 201906240039). JW was supported by the Visiting International Research Students Grant (#5139), UBC (to M. Hassan). We thank Eric Leinberger for helping prepare the figures and Cormac Chui for helping edit the language.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Hongwei Zhou.

Supplementary Information

Below is the link to the electronic supplementary material.

Supplementary file1 (DOCX 24111 KB)

Rights and permissions

Springer Nature or its licensor holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Wang, J., Hassan, M.A., Saletti, M. et al. Experimental study on the mitigation effects of deflection walls on debris flow hazards at the confluence of tributary and main river. Bull Eng Geol Environ 81, 354 (2022). https://doi.org/10.1007/s10064-022-02850-5

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1007/s10064-022-02850-5

Keywords

Navigation