The purpose of the collaboration between LAMPIT (Department of Soil Defence, University of Calabria) and CMCC is to develop an hydro-meteorological chain in order to abtain a reliable tool in the context of flood evolution prediction able to provide quantitative information of practical importance within the civil protection activities.
The LAMPIT contribution to the project concerns the mathematical description of both the generation and propagation of flood events at basin scale. The work here presented has been carried out in close cooperation with CIRA researchers (dr. Pasquale Schiano and dr. Paola Mercogliano) and DISTART (Dipartimento di Ingegneria delle Strutture, dei Trasporti, delle Acque, del Rilevamento, del Territorio – University of Bologna) researchers (Prof. Armando Brath, Ing. Elena Toth and Ing. Alessio Domeneghetti).
The mathematical representation of the flow processes is based on the fully dynamic shallow water equations. The solution of these equations, excluding some simplified cases, can be obtained by numerical integration only. Many schemes based on fully dynamic and simplified shallow water equations have been proposed in literature. Some of these schemes have been implemented in the LAMPIT laboratory and applied to simulate simple cases of overland flow as already presented. Afterwards the inplemented codes have been applied to simulate overland flow over real topography.
In this contest some numerical anomalies appeared due to the presence of small water depth over high slope and irregular topography. According to that a careful analysis of these problems has been made and some numerical techniques have been implemented in order to prevent them. Finally the developed model has been applied to simulate a rainfall event in a Reno sub basin. A Digital Elevation Model (DEM) with 20 m cell size has been generated from topographical maps of the area in 1:10000 scale, using a GIS software and the Corine map has been used to obtain the land use/land cover for the watershed. Varying in time and in space effective rainfalls, computed by DISTART researchers, have been fed in the model as input data. The model has been calibrated and validated using the rainfall event occured in Reno basin on 7-9th November 2003. The numerical results have been compared with the observed data and found to be satisfactory. A sensitivity study of the roughness parameter has been also carried out. Finally the hydro-meteorological chain has been implemented to simulate the same rainfall event on Reno basin at Pracchia Station starting from rainfall data simulated by the CIRA researchers using a meteorological model. The developed model seems to be an useful tool for the simulation of overland flow events.
CMCC InstitutesCMCC Divisions
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- Keywords: Flood propagation, Hydrometeorological chains