Search results for " Idrologia"

Comparative analysis of different techniques for spatial interpolation of rainfall data to create a serially complete monthly time series of precipit…

2011

Abstract The availability of good and reliable rainfall data is fundamental for most hydrological analyses and for the design and management of water resources systems. However, in practice, precipitation records often suffer from missing data values mainly due to malfunctioning of raingauge for specific time periods. This is an important issue in practical hydrology because it affects the continuity of rainfall data and ultimately influences the results of hydrologic studies which use rainfall as input. Many methods to estimate missing rainfall data have been proposed in literature and, among these, most are based on spatial interpolation algorithms. In this paper different spatial interpo…

Detecting the chaotic nature of advection in complex river flows

2012

In order to detect signatures of chaotic advection in river surface motion, surface buoys equipped with GPS were deployed in a field experiment in River Danube, Hungary. The buoys were released in the vicinity of groynes where complex mixing processes occur. A detailed analysis of the trajectories was carried out, focusing on the time evolution of the distance between buoy pairs. The analysis included the determination and comparison of local Lyapunov exponents and prediction times of finite-time hyperbolic behaviour, which is related to strong mixing. Despite of the small number of applied buoys we found evidence on Lagrangian chaos in the wake of a groyne field. In order to supplement the…

CALYPSO, a permanent and operational network of High-Frequency radar observing systems for real-time monitoring of surface currents in the Malta-Sici…

2014

Illegal migration often results in dramatic loss of lives that can be avoided with timely Search and Rescue (SAR) interventions; such SAR services require accurate information such as on sea-state and operational tools such as trajectory forecasting for floating objects at sea. The maritime transport of oil crossing this region accounts for 25% of the global maritime traffic and for nearly 7% of the world oil accidents over the last 25 years. In combination with localized oil extraction plants existing in the shelf zones this situation presents a serious threat to both the open-sea and coastal-zone habitats, with consequent impacts on local economic activities as tourism and fisheries, impa…

On the influence of using binary and distributed information for 2D hydraulic model calibration and uncertainty evaluation

2013

Floods are considered the most frequent natural disaster world-wide and may have serious socio economic impacts in a community. In order to accomplish flood risk mitigation, flood risk analysis and assessment are required to provide information on current or future flood hazard and risks. Hazard and risk maps involve different data, expertise and effort, depending also on the end-users. More or less advanced deterministic approaches can be used, but intuitively probabilistic approaches seem to be more correct and suited for modelling flood inundation given typical uncertainties. Two very important matters remain open for research: the calibration of hydraulic models (oriented towards the es…

THE PROBLEM OF MISSING DATA IN HYDROCLIMATIC TIME SERIES. APPLICATION OF SPATIAL INTERPOLATION TECHNIQUES TO CONSTRUCT A COMPREHENSIVE ARCHIVE OF HYD…

2011

Planning, management and e ective control of water resource systems, require a considerable amount of hydrological data variables such as rainfall, temperature, stream- ow, etc.. Such data are required when a hydrological model has to be developed, as well. Very often hydrological data sequences at a given gauge have gaps or are incomplete, or are not characterized by a good quality or are not su ciently length. This can severely a ect, for example, the reliability of the design of a hydropower plant, the construction of dams, etc. Furthermore, the problem of missing values is a common obstacle in time series analysis and speci cally in the context of rainfall, temperature and rainfall runo…

Pluvial flooding in urban areas: the role of surface drainage efficiency

2018

Pluvial flooding in urban areas may derive from the limited or temporarily reduced efficiency of surface drainage, even when the underlying storm sewers are properly designed. This study focuses on the impact of uncertainties in the operational condition of the surface drainage system on pluvial flood hazard. The flood propagation model FLURB-2D is implemented on a selected study area in the town of Genoa (Italy). Synthetic hyetographs based on the Chicago and bivariate copula methods with suitable return periods are used as input. While simulating the design rainfall, inlet operational conditions are varied stochastically using a Monte Carlo approach. Results confirm that microtopography h…

Modeling the hydrological and mechanical effect of roots on shallow landslides

2016

This study proposes a new methodology for estimating the additional shear strength (or cohesion) exerted by vegetation roots on slope stability analysis within a coupled hydrological-stability model. The mechanical root cohesion is estimated within a Fiber Bundle Model framework that allows for the evaluation of the root strength as a function of stress-strain relationships of populations of fibers. The use of such model requires the knowledge of the root architecture. A branching topology model based on Leonardo's rule is developed, providing an estimation of the amount of roots and the distribution of diameters with depth. The proposed methodology has been implemented into an existing dis…

Parameter Uncertainty in Shallow Rainfall-triggered Landslide Modeling at Basin Scale: A Probabilistic Approach

2014

Abstract This study proposes a methodology to account for the uncertainty of hydrological and mechanical parameters in coupled distributed hydrological-stability models for shallow landslide assessment. A probabilistic approach was implemented in an existing eco-hydrological and landslide model by randomizing soil cohesion, friction angle and soil retention parameters. The model estimates the probability of failure through an assumed theoretical Factor of Safety (FS) distribution, conditioned on soil moisture content. The time-dependent and spatially distributed FS statistics are approximated by the First Order Second Moment (FOSM) method. The model was applied to the Rio Mameyes Basin, loc…

MODELING THE TERRAIN EVOLUTION AT BASIN SCALE: THE GEOMORPHIC COMPONENT OF TRIBS HYDROLOGICAL MODEL

2012

A coupled eco-hydro-geomorphic investigation of basin response to climate change: Examining the role of climate on internal basin dynamics

2009

Much attention has been devoted to assessing the relationship between changes in climate and landscape evolution. Given the complexity of dependence of geomorphic processes on hydrological and vegetation properties of the system, it is not surprising that different studies of fluvial response to climate change often appear contradictory, making difficult to generalize about how any given drainage basin will respond to changes in climate and/or land use. In this study, an integrated geomorphic component of the physically-based, spatially distributed hydrological model, tRIBS, the TIN-based Real-time Integrated Basin Simulator, is used to analyze the sensitivity of landscapes to climate chang…