Author(s): Majone Ugo; Mignosa Paolo; Tomirotti Massimo
Linked Author(s):
Keywords: Floods; Statistical methods; Synthetic design hydrographs; Regionalization; Hydraulic risk
Abstract: The design of flood protection measures requires in many cases not only the estimation of the peak discharges, but also of the volume of the floods and – possibly – of its time distribution. Typical examples include the design or verification of flood control reservoirs and the definition of inundation maps by means of 1D or 2D unsteady flow models. A possible solution to this kind of problems is the formulation of Synthetic Design Hydrographs (SDH). SDHs do not represent any historical floods, but they have to describe the statistical main characteristics of the observed hydrographs in order to assure satisfactory results for the purposes for which they are introduced. The present paper summarizes the results of some studies carried out by the writers in the last years on the topic of the estimation of synthetic design floods. The procedure has already been presented in papers published on journals and conference proceedings but some aspects are here re-examined on the basis of new critical remarks and a new case study is added. In particular, some applications of the SDHs to the study of the hydraulic behaviour of natural (river flood propagation) and artificial (flood control devices) systems are shown; as a further application to flood routing problems, the important case of Maggiore lake (Northern Italy) is considered. The proposed methodology for the estimation of the SDHs can be immediately applied in the case of gauged sites. However, it can be extended also to ungauged sites by means of a regionalization of the characteristics involved in the SDH definition: peak discharges, flow duration frequency reduction curves and peak position. As application examples of these procedures, the results obtained for some rivers of Mid -Northern Italy and for the Po - the main Italian river - are shown.
Year: 2007