HyFlux2: a Numerical Model for the Impact Assessment of Severe Inundation Scenario to Chemical Facilities and Downstream Environment
Following a number of catastrophic dam-failure accidents and the accompanying environmental disasters (e.g. Baia Mare, Romania 2000), the tailings ponds of mining activities entered in the scope of the Seveso Directive. This Directive, which deals with the control of major accident hazards, requires the assessment of consequences for all relevant accident scenarios, including those referring to dam rupture.
The HyFlux2 model has been developed to simulate flood inundation due to dam break. However, it is able to simulate other severe inundation scenarios such as tsunami-wave run-up and flash flood. The model solves the conservative form of the two-dimensional shallow water equations using the finite volume method. The interface flux is computed by a Flux Vector Splitting method based on a Godunov-type approach. A second-order scheme is applied to the water surface level and velocity, assuring the balance between fluxes and sources also for complex bathymetry and topography, i.e. also in presence of bottom steps and shorelines. The second-order scheme provides results with high accuracy, also in the presence of dry/wet fronts.
The model adopts the raster grid so that a GIS Digital Elevation Model can be directly imported into the model. The developed model is validated in this paper with a dam-break case study. It is shown that the HyFlux2 model can correctly account for complex real dam-break flows, giving a satisfactory prediction of the major characteristics such as water depth, water velocity, flood extent, and flood-wave arrival time. It is also demonstrated that the model is robust, computationally efficient and fully mass conservative.
The results provided by the model are of great importance for the assessment and management of risk in a number of Seveso establishments with certain characteristics. In case of tailings ponds this information is necessary for modelling the dispersion of pollutants to the downstream environment. Similarly, in the case of downstream chemical facilities where a dam-break can provoke chemical releases, the model provides the necessary information to assess the impact and the risk of such a scenario.
FRANCHELLO Giovanni;
KRAUSMANN Elisabeth;
2008-05-20
OPOCE
JRC36005
1018-5593,
EUR 23354 EN,
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