FLORA-2D: A New Model to Simulate the Inundation in Areas Covered by Flexible and Rigid Vegetation

A two-dimensional (2D) hydraulic model for river flood inundation prediction is presented. This model named FLORA-2D (FLOod and Roughness Analysis) solves the shallow-water equations at each node of a regular mesh covering the channel and floodplain. Its special feature is the ability to consider the flow resistance due to vegetation as a function of both space and time. So, during a flood, in each grid node the resistance of vegetation is calculated considering the hydraulic characteristics of the flow which may vary over time as well as the characteristics of the plant. The model was tested in a study of a flood event which occurred on the River Bradano, Southern Italy, in March 2011. A first evaluation of the behavior of the model shows a good correspondence with the theories used in the code. Furthermore a satellite image acquired during the flood provided an observed flood extent against which to compare the predicted extent.