Author(s): A. Paquier; P. Farissier; P. Ramez; S. Haider; P. Maurel
Linked Author(s):
Keywords: Shallow water equations; 2-D modelling; Flood risks; Embankment urban catchment
Abstract: Simulating flooding process using 2-D model provides detailed water depths and velocities. This information may be directly used for assessment of flood risks and thus became the basis for prevention or emergency measures and for the development of a specific information system. The three cases described are typical of the use of 2-D model: complex hydraulic network the topology of which changes because of flooding for confluence of Oignin River, breaching of embankment for a flood plain along Loire River and flood passing through the streets of the town of Nimes. Such simulations require that adapted methods are used. First, a convenient modelling should include a right description of the topography, which means a computational grid which takes into account the main features of natural ground level and the main linear man-made structures. The extreme case is the urban area in which obstacles to flow (essentially buildings) constitute the major part of the flooded area. Then, the numerical method should be able to represent both subcritical and supercritical flows and the transitions between them and to integrate the description of the flow through hydraulic structures. Such structures should be as complex as a breaching in an embankment. Code Rubar 20 developed by Cemagref meets these requirements and seems to simulate such complex situations in a suitable way.
Year: 2001