DTM impact on the results of dam break simulation in 1D hydraulic models

Abstract

Dam break simulation has been quite long established module in the hydraulic modeling industrial standards, which are represented in particular by the software packages USACE HEC-RAS and DHI MIKE 11 worldwide including the Czech Republic. Coincidentally, at this level, both previously mentioned hydraulic models are using identical numerical solvers DAMBRK and WSPRO. It can be expected that the use of identical schematization of the river channels and technical objects together with the parameterization of dam body and its geometric parameters will give the comparable results of hydraulic simulations. When the same approach is applied for the reservoir and dam schematization together with its operational rules, the simulations using the identical solver DAMBRK will produce almost same results. Finally, the differences of the generated floodlakes by these particular models will be most affected by the accuracy and resolution DMT/DMR and partly by the different simulation concepts of water flow in the inundation area within each individual model. Because of the extreme situations of the “dam break” are occurring rarely (in the Czech Republic with larger water works only once), the calibration data is virtually absent. It is certainly not an argument to tell, that the simulation apparatus for HPPS and POVIS in the scope of the crisis management and planning was not prepared for these situations. A sensitivity analysis is among the crucial conditions of the successful modelling. This paper focuses particularly on the impact of DTM accuracy on dam break simulations.