1,720,988 research outputs found
SENSITIVITY ANALYSIS TO ROUGHNESS FOR THE ASSESSMENT OF FLOOD HAZARD IN LOWLAND AREAS
No full textThe present paper discusses the first results of the sensitivity to roughness of a two-dimensional hydrodynamic to simulate flooding in particularly low lying areas. In such areas ,which lack well defined morphological boundaries , the characteristics and variation of the vegetation cover could also significantly influence the extent and hydraulic characteristics of the flood. This research is envisaged as the first step of a study of roughness characterization of the Lucanian Ionic coastal plain in relation to the type of cultivation present, based on data collected by a terrestrial laser-scanner. Such an analysis will lead to a reduction in uncertainties in the identification of flood risk linked to approximations in the choice of the roughness coefficient of the flood plain
RISCHIO IDRAULICO IN AREE PIANEGGIANTI: ANALISI MEDIANTE MODELLI IDRODINAMICI BIDIMENSIONALI E DATI TOPOGRAFICI DA LASER SCANNER
No full textNella presente memoria si riportano alcune elaborazioni realizzate presso il Diparti-mento d’Ingegneria e Fisica dell’Ambiente (D.I.F.A.) dell’Università degli Studi della Basilicata nell’ambito di una convenzione con l’Autorità Interregionale di Bacino della Basilicata, finalizzata alla valutazione del pericolo di inondazione lungo la costa jonica lucana.
La natura estremamente pianeggiante di tale area rende la stima dell’inondabilità particolarmente complessa: qui, infatti, l’assenza di limiti morfologici definiti, propri dei tratti medio-alti dei bacini idrografici, rende complessa l’individuazione del perime-tro dell’eventuale allagamento.
Alla stima dell’estensione dell’allagamento e delle caratteristiche idrauliche della corrente sulla pianura di inondazione si è giunti attraverso l’utilizzo di modelli idrodi-namici bidimensionali di simulazione delle piene, implementati a partire da modelli di-gitali del terreno ottenuti da rilievo laser-scan. Dai risultati idraulici ottenuti si avanza una proposta di classificazione della pericolosità di inondazione funzione sia del tempo di ritorno che del tirante idrico massimo valutato sulla pianura di inondazione
Flood vulnerability evaluation in complex urban areas.
No full textThis paper deals the conception, the development and the subsequent validation of an integrated numerical model
for the assessment of systemic vulnerability in complex and urbanized areas, subject to flood risk.
The proposed methodology is based on the application of the concept of “systemic vulnerability”, the model is
a mathematician-decisional model action to estimate the vulnerability of complex a territorial system during a
flood event. The model uses a group of “pressure pointers” in order to define, qualitatively and quantitatively, the
influence exercised on the territorial system from factors like as those physicists, social, economic, etc..
The model evaluates the exposure to the flood risk of the elements that belong to a system.
The proposed model, which is based on the studies of Tamura et al., 2000; Minciardi et al., 2004; Pascale et al.,
2008; considers the vulnerability not as a characteristic of a particular element at risk, but as a peculiarity of a
complex territorial system, in which the different elements are reciprocally linked in a functional way.
The proposed model points out the elements with the major functional lost and that make the whole system
critical.
This characteristic makes the proposed model able to support a correct territorial planning and a suitable
management of the emergency following natural disasters such as floods.
The proposed approach was tested on the study area in the city of Potenza, southern Italy
SENSITIVITY ANALYSIS IN FLOOD MODELING OF FLAT AREAS
No full textThe study of fl ooded areas is derived from detailed knowledge
of the area under consideration (river and fl oodplain), hydrological
analysis and hydraulic modeling.
The estimated risk of fl ooding is now facilitated by survey
systems able to create enable the creation of highly detailed digital
terrain models (COBBY et alii, 2001), by complex mathematical
models and sophisticated hardware and software which permit the
achievement of complex elaborations within satisfactory time periods.
However, the construction of the simulation model is always a
compromise between the capability of the instruments and the detail
that you want to achieve. So it can be useful to verify the extent of
changes in hydraulic parameters of output compared to the choices
made on the input parameters This is especially true when observed
data of fl ood events are absent.
Considering an extremely flat area, this work aims to analyze
the results of hydrodynamic bi-dimentional simulations depending
on the detail achieved in the characterization of the study area
(expressed through the computational domain resolution) and the
floodplain roughness
FLORA-2D: A New Model to Simulate the Inundation in Areas Covered by Flexible and Rigid Vegetation
No full textA two-dimensional (2D) hydraulic model for river flood inundation prediction is presented. This model named FLORA-2D (FLOod and Roughness Analysis) solves the shallow-water equations at each node of a regular mesh covering the channel and floodplain. Its special feature is the ability to consider the flow resistance due to vegetation as a function of both space and time. So, during a flood, in each grid node the resistance of vegetation is calculated considering the hydraulic characteristics of the flow which may vary over time as well as the characteristics of the plant. The model was tested in a study of a flood event which occurred on the River Bradano, Southern Italy, in March 2011. A first evaluation of the behavior of the model shows a good correspondence with the theories used in the code. Furthermore a satellite image acquired during the flood provided an observed flood extent against which to compare the predicted extent
Development and application of hydraulic two-dimensional modelling for flood risk protection
No full textPiani di Assetto Idrogeologico: valutazioni in merito al pericolo di inondazione in aree costiere e pianeggianti
No full textIl modello bidimensionale FLORA-2D per la propagazione delle piene considerando le variazioni spazio-temporali della resistenza al moto indotta da vegetazione
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