Carmelina Costanzo

Visual Risk Communication of Urban Flooding in 3D Environments Based on Terrestrial Laser Scanning

In this paper, attention is focused on the extension of the urban flood-mapping concept from an eminently cartographic context to a three-dimensional one, by applying techniques for the representations of urban flood inundation in a virtual environment for hazard communication purposes. In particular, visual risk communication of urban flooding in 3D environments, based on terrestrial laser scanning, has been analyzed here. Moreover, a web-based rendering of point clouds for the visualization of urban flooding has been explored in order to highlight its benefits in urban flood risk communication.

Final Document on the Third Year, Second Activity: 'General Methodologies and Hydrological-Hydraulic Parameters Supporting the Definition of a Climate Index for Changing Flood Risk Assessment'

This report is the final document related to the third year, second activity whose title is: General methodologies and hydrological-hydraulic parameters supporting the definition of a climate index for changing flood risk assessment. The purpose of the collaboration between LAMPIT (department of Soil Defence, University of Calabria) and CMCC is to develop an hydrometeorological chain in order to obtain 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 generation and propagation of flood events at basin scale. The work here presented has been carried out in close cooperation with dr. Pasquale Schiano and dr. Paola Mercogliano. In order to embrace the problem as a whole, this report starts from a general overview of the characteristics of climate change according to IPCC evaluations, highlighting the main causes that may induce a variation of flood features (chapter 1). The term flood is often generically associated to a number of natural events that significantly differ in terms of phenomenological generation. So it seems necessary to recall in mind a possible main classification of flood phenomena in order to underline the flood type discussed herein and his peculiarities in relation to climate change (chapter 2). In a catchment-wide perspective there is the need to take into account non-climatic drivers, such as land-use change, in the evaluation of changing flood risk: land cover change within a watershed is recognized as an important factor affecting runoff and it is possible that the transformation of land across the globe could have a greater influence on runoff than climate change; that question is explained in the chapter 3. Chapter 4 is devoted to the general methodologies developed to evaluate the effects of climate change on runoff. They are mainly based on the interconnection between climate and hydrologic models; some features of each model are also analysed to highlight those aspects useful for the evaluation of climate impact on river flooding that link climate models to hydrological model. In order to better characterize the general methodologies, a number of typical results, presented in the literature, are illustrated in the chapter 5. The analysis related to the impact of climate change on flood risk is affected by a significant degree of uncertainty; some consideration on the uncertainty source is presented in the chapter 6. Finally in the chapter 7, the concept of climate elasticity of streamflow, considered to be an important indicator identifying the sensitivity of streamflow to climate change, is presented.

Final Document on the Third Year, Third Activity: 'Coupling Meteorological and Hydraulic Modelling to Develop a Hydro-Meteorological Chain: Simulation of a Test Case'

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.