Document Type
Presentation
Publication Date
8-1-2014
Abstract
This paper presents an integrated approach that enables the simultaneous modeling of dike breaching process and flood propagation. The dike breaching process is modelled with a simple breach model implemented into a 2-dimensional hydrodynamic flood model – Telemac2D. Telemac2D models the propagation of the arising flood into the hinterland. The breach model generalizes dike breaching process in two general stages. In the first stage, dike breaching is predominantly vertical with limited lateral breach growth; and in the second stage breach grows only laterally. The breach model requires breach location, breach duration, and length and axis of dike affected by the breach as input parameters. Breach starts at the center of the dike length affected by the breach and can be initiated in three different ways: at a given time, based on water level on the dike or based on water level at a given point. The first stage takes one tenth of the total time required for the entire breach and has a breach width equal to one tenth of the final breach width. The approach is exemplarily applied to model the year 1996 Awash River dike breach flood at Wonji, Ethiopia, a historic dike breach flood that destroyed the sugar plantation and offices of Wonji Shoa Sugar Factory. The water depth calculated with the numerical model is in good agreement with the water level mark left on buildings as witnessed by people present at the place after the disaster, including the dike foreman.
Comments
Session R39, Assessment, Prediction, and Management of Flood Events I