Journal cover Journal topic
Natural Hazards and Earth System Sciences An interactive open-access journal of the European Geosciences Union
https://doi.org/10.5194/nhess-2017-372
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 4.0 License.
Research article
23 Oct 2017
Review status
This discussion paper is a preprint. It is a manuscript under review for the journal Natural Hazards and Earth System Sciences (NHESS).
Formation, breaching and flood consequences of a landslide dam near Bujumbura, Burundi
Léonidas Nibigira1, Hans-Balder Havenith1, Pierre Archambeau2, and Benjamin Dewals2 1Geohazards and Environment, Department of Geology, University of Liege, 4000 Liege, Belgium
2Hydraulics in Environmental and Civil Engineering (HECE), Research unit Urban & Environmental Engineering, University of Liege, 4000 Liege, Belgium
Abstract. This paper investigated the possible formation of a landslide dam on the Kanyosha River near Bujumbura, the capital of Burundi, as well as the interplay between the breaching of this landslide dam and the flooding along the river. We present an end-to-end analysis, ranging from the origin of the landslide up to the computation of flood waves induced by the dam breaching. The study includes three main steps. First, the mass movement site was investigated with various geophysical methods that allowed us to build a general 3D model and detailed 2D sections of the landslide. Second, this model was used for dynamic landslide process modelling with the Universal Distinct Element Code. The results showed that a fifteen-meter-high landslide dam may form on the river. Finally, a 2D hydraulic model was setup to find out the consequences of the breaching of the landslide dam on flooding along the river, especially in an urban area located downstream. Based on 2D maps of maximum water depth, flow velocity and wave propagation time, the results highlight that neglecting the influence of such landslide dams leads to substantial underestimation of flood hazard in the downstream area.

Citation: Nibigira, L., Havenith, H.-B., Archambeau, P., and Dewals, B.: Formation, breaching and flood consequences of a landslide dam near Bujumbura, Burundi, Nat. Hazards Earth Syst. Sci. Discuss., https://doi.org/10.5194/nhess-2017-372, in review, 2017.
Léonidas Nibigira et al.
Léonidas Nibigira et al.
Léonidas Nibigira et al.

Viewed

Total article views: 155 (including HTML, PDF, and XML)

HTML PDF XML Total BibTeX EndNote
124 27 4 155 1 1

Views and downloads (calculated since 23 Oct 2017)

Cumulative views and downloads (calculated since 23 Oct 2017)

Viewed (geographical distribution)

Total article views: 155 (including HTML, PDF, and XML)

Thereof 154 with geography defined and 1 with unknown origin.

Country # Views %
  • 1

Saved

Discussed

Latest update: 18 Nov 2017
Publications Copernicus
Download
Short summary
Flood prediction methods are often based solely on climatic parameters and sometimes on the failure of existing dams. This paper shows the importance of multi-risk studies, including potential natural dams formation to avoid risk underestimation. We present an end-to-end analysis, ranging from the origin of the landslide up to the computation of flood waves induced by the dam breaching. The paper is based on a case study of Bujumbura in the East African Rift Valley, a multi-hazard environment.
Flood prediction methods are often based solely on climatic parameters and sometimes on the ...
Share