MATHEMATICAL MODELS FOR FLOOD HAZARD ASSESSMENT

One-third of the annual natural disasters and economic losses, and more than half of the respec-tive victims are fl ood-related. Knowledge and advanced scientifi c tools play a role of paramount importance in the strain of coping with fl ooding problems. The paper, after a brief discussion of the terms hazard, vulnerability, and risk, presents the governing equations for 1D, 2D, and 3D models, together with examples of their applications and discussion of the carried out results. It is shown that 1D models can be used only in very particular cases, but actually they are still the most reliable and robust of all the models; wide spread use of 2D models is justifi ed by the relatively easiness in their use, and because the time consumption is still quite reduced. As for 3D models, their use in environmental hydraulic is still limited to very peculiar cases, because of the diffi culties encountered in their use and the impressive time consumption they require, which in the largest cases necessitates the dramatic simplifi cation of the topography or of the turbulence models that implies poor quality results