Prediction of Avulsion Phenomenon on Alluvial Fans Using FLO-2D Hydraulic Model

Document Type : Original Article

Authors

1 - M.Sc. graduate, Drainage and Irrigation Engineering, Ferdowsi University of Mashhad, Mashhad, Iran

2 M.Sc. graduate, Water Resources Management, Ferdowsi University of Mashhad, Mashhad, Iran

3 Assistant Professor, Department of Water Engineering, Ferdowsi University of Mashhad, Mashhad, Iran

4 Associated Professor, Department of Water Engineering, Ferdowsi University of Mashhad, Mashhad, Iran

Abstract

The risk of flood incorporated with the potential of channel shift across the width of alluvial fans may cause substantial damages. This shift is called avulsion. The earlier methods of determining avulsion on alluvial fans (such as FAN mathematical model) were received negative criticism and did not give accurate results. Given that flow on alluvial fans is two-dimensional, FLO-2D model was used in this research to identify the areas with avulsion potential. The avulsion phenomenon was studied on two alluvial fans in Iran; one in the North-east (Ferizi) and one in the south-east (Sarbaz). Using this model, flow was simulated based on 100 and 500-year discharges. Then areas with avulsion potential were identified by plotting the results of the model on the recent aerial photographs of the alluvial fans. Results showed that massive evulsions had happened in the areas with no expectation of such phenomenon. Thus, using this method can help to identify areas with avulsion risk and reduce the potential damages caused by it.

Keywords

References

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History

  • Receive Date: 03 September 2014
  • Accept Date: 27 August 2015

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