Modern techniques for flood risk analysis: quasi-3D simulations in a GIS environment

Human beings have continuously attempted to adapt their environment to their needs.
However, many natural phenomena still remain challenging to control and the populations
must undergo sometimes heavily damaging consequences. It is consequently essential to study these phenomena in order to assess their potential hazards. In particular, the scope of the present paper focus on floods.
The intense floods met these last years showed the importance of this phenomenon
as well as its many devastating effects. Thanks to recent important breakthroughs,
both in the field of conceptual and numerical modelling of complex flows and in the
calculation power of computers, it is henceforth possible to study the effects of potential
floods on the basis of numerical simulations, with an accuracy never reached
beforehand.
The Laboratory of Applied Hydrodynamics and Hydraulic Constructions (HACH) of
the University of Liege has always made this kind of study one of its core competencies,
thanks to
• the development of modern and powerful modelling tools (quasi-three dimensional
software for flow simulation by finite volume),
• the use of a broad range of data enabling a proper representation of the studied
fields (topography, occupation of the ground...)
• the systematic validation of simulation results.
These tools are currently intensively used within the framework of a general study of
the flood-prone zones of the Walloon area of Belgium, which corresponds to more
than 800 km of rivers.