Final Scientific Report: 'Processing and Hydrogeological Analysis of the Data of the November 2003 Flood Event in the Reno River Closed at Pracchia'

Abstract

An interesting case study for the implementation of the model was identified by the DISTART research group in the Northern Apennine Mountains, as requested by the LAMPIT research group. The identified watershed is the most upstream part of Reno river basin, at the closure section of Pracchia, located in the Tuscan part of the Reno watershed, close to the border with the Regione Emilia Romagna. Following an analysis of the rainfall and stream flow data collected from 2002 and 2007, the flood event that took place at the beginning of November 2003 (days 7-9) was identified as one of the most severe meteorological events in the whole observation period. The rainfall event was characterized by high rainfall intensities for several hours over the entire northern Apennine area and it corresponded to a significant flood hydrograph at the Pracchia cross-section. As required by the LAMPIT and CIRA, the following data, needed for the implementation of both hydrological/hydraulic and meteorological modelling, were collected, processed and delivered to either the CIRA or the LAMPIT research groups by the end of July 2009. In addition to the collection and processing of the above data, the DISTART group performed the research activities needed for issuing the following products (delivered to the LAMPIT research group on the 30th September 2009): the spatially distributed hourly rainfall fields on the basis of the ground raingauge data, for each hour from 0.00, 7 November 2003 to 23.00, 9 November 2003, that is the total (or gross) hourly rainfall fields (in a matrix form, following the standards required by the LAMPIT research group, that is for cells of 20 m x 20 m) over the watershed area; an estimate of the spatio-temporal distribution of the net rainfall, that is of the part of the gross rainfall that actually becomes surface runoff (or overland flow). Net rainfall is obtained is subtracting from the gross rainfall the water losses ascribed to: interception by the vegetation, depression storage (or surface retention) and infiltration. A net rainfall map, over the watershed (plus buffer) area, was computed for each hour from 0.00, 7 November 2003 to 23.00, 9 November 2003.