Resumen de Influencia del transporte de detritos leñosos (woody debris) en la peligrosidad por avenidas torrenciales
V. Ruiz Villanueva, José María Bodoque del Pozo, Andrés Díez Herrero, M.A. Eguibar Galán
An important flash flood, accompanied by the transportation of large quantities of woody material, occurred in 1997 in the Sierra de Gredos (Central Spain).The woody remnants clogged a bridge section, raising the water level upstream. The aim of this work is to analyse the influence of wood in the flood hazard pattern. Hydraulic simulation through an iterative process was used to reconstruct bridge obstruction. It was observed that the flooded areas were different from those where there was no wood. This conclusion helped define the concept of equivalent return period, as the recurrence interval of an event where an obstruction is present is equivalent in depth and extension to an event without obstruction. According to this concept, the magnitude of the event magnitude may be up to eight times greater as the obstruction increases. These results highlight the need to include obstruction phenomena in flood hazard analyses
