Two-dimensional modelling of large wood transport during flash floods

Auteur(s) et Affiliation(s)



Description :
Large woody material (LWM) transported by rivers may be entrapped at critical stream geometry configurations (e.g. bridges) and therefore increase the destructive power of floods. This was the case in a central Spanish mountain river (Arroyo Cabrera) where a flood event with a high degree of LWM transport took place in 1997. A two-dimensional numerical model was developed to simulate the transport of LWM and its effect on hydrodynamics. Different scenarios for the wood transport rate allowed to study the influence of inlet boundary conditions on bridge clogging. The scenario which best reproduced the bridge clogging effect and flood characteristics was one in which 60% of the total wood entered before the peak discharge. This dropped to 30% at the peak itself, and finally fell to 10% during the recession curve. In addition, the accumulation patterns of LWM along the reach were computed and compared with post-event field photographs, showing that the model succeeded in predicting the deposition patterns of wood and those areas prone to form wood jams.


Type de document :
Article de périodique

Source :
Earth surface processes and landforms, issn : 0197-9337, 2014, vol. 39, n°. 4, p. 438-449, nombre de pages : 12, Références bibliographiques : 2 p.

Date :
2014

Editeur :
Pays édition : Royaume-Uni, Chichester, Wiley