Papers by Alberto Lamberti

Extreme met-ocean conditions cause proportioned wave run-up and load on sand dunes which potentia... more Extreme met-ocean conditions cause proportioned wave run-up and load on sand dunes which potentially trigger the formation of a fast growing dune breach leading to coastal flooding. The objective of this study is to investigate deterministically how and to what extent waves trigger and drive breaching of sand dunes. The selected study area is Emilia-Romagna (Italy) where these processes were investigated in detail with focus on wave impact, when lateral erosion (alongshore) occurs leading to breaching of the dune systems. Spatial and temporal high-resolution numerical simulations using the XBeach morphological model were carried out to study wave run up, overtopping and breaching of sand dunes along a representative reach of Emilia-Romagna coastal dunes. Unlike previous studies, XBeach was set up in 2D mode using the built-in non-hydrostatic module in order to model the dispersive waves with high accuracy. This allows to investigate the alongshore evolution of the breach, triggered ...

Coastal Engineering, 1997
Physical model tests have been performed in two different wave flumes to analyse the threshold of... more Physical model tests have been performed in two different wave flumes to analyse the threshold of stone movement and quantify the frequency and length of displacements due to head-on wave attacks at a reshaping breakwater. Data on stone movements were obtained from the observation of cumulative displacements at the end of each wave attack and from video records during the attack. Threshold conditions, frequency of movement and displacement length are expressed as function of a suitably modified stability number.A simple model is defined relating longshore transport due to oblique wave attack to stone mobility. The transport model is based on the assumption that movement statistics is affected by obliquity only through the appropriate mobility index and that stones move during up- and down-rush in the direction of incident and reflected waves. Without any calibration, results compare favourably with experimental data available in literature in the range of low mobility conditions where movement statistics was observed. A calibration is provided in order to obtain an accurate transport formula valid in a wide mobility range i.e. for reshaping breakwaters and up to gravel beaches.

Oil–shoreline interaction (or “beaching” as commonly referred to in literature) is an issue of ma... more Oil–shoreline interaction (or “beaching” as commonly referred to in literature) is an issue of major concern in oil spill modeling, due to the significant environmental, social and economic importance of coastal areas. The present work studies the improvement of the representation of beaching brought by the introduction of the Oil Holding Capacity approach to estimate oil concentration on coast, along with new approaches for coast type assignment to shoreline segments and the calculation of permanent oil attachment to the coast. The above were tested for the Lebanon oil spill of 2006, using a modified version of the open-source oil spill model MEDSLIK-II. The modified model results were found to be in good agreement with field observations for the specific case study, and their comparison with the original model results denote the significant improvement in the fate of beached oil brought by the proposed changes.

Journal of Waterway Port Coastal and Ocean Engineering-asce, 2003
A model to estimate volume loss of armor stones caused by abrasion under wave conditions occurrin... more A model to estimate volume loss of armor stones caused by abrasion under wave conditions occurring during a structure's lifetime is proposed. It accounts only for abrasion caused by stone movements, neglecting the effects of stone breakage, wetting-drying, freezing-thawing cycles, and chemical attack and is based on the assumption of proportionality between abraded volume and abrasion work. The model represents rock resistance to abrasion and to unit size and makes use of empirical relationships providing the average frequency of movement and displacement length of armor units. Wave loading is described with a probabilistic analysis. The present model is discussed in the light of a previous one. The comparison makes possible the estimation of the influence of external agents, other than stone mobility and size, on volume loss.

Coastal Engineering, 2007
This contribution outlines the philosophy and procedures adopted in a major European research pro... more This contribution outlines the philosophy and procedures adopted in a major European research project focused on the development of video systems in support of coastal zone management. The CoastView project has developed video-derived Coastal State Indicators (CSIs) that directly facilitate management decisions. Coastal State Indicators are defined here as, "A reduced set of issue-related parameters that can simply, adequately and quantitatively describe the dynamic-state and evolutionary trends of a coastal system". The process of defining useful CSIs involves close interaction between coastal managers, scientists and policy makers. Even with frequent formal discussions and colloquia between these parties the process of defining useful indicators frequently fails. An approach . Matching specialist knowledge with end-user needs. PhD Thesis, University of Twente, Enschede, The Netherlands, 173 p.] is described in this paper which guarantees the effectiveness of the resulting CSIs, and enhances the communication process between scientist and coastal managers. Some practical examples of the frame of reference are given by way of illustration and a detailed description is given of the procedure adopted within the CoastView project for defining and evaluating CSIs. The philosophies and methodologies used during the three year CoastView project have proved successful and provide a valuable template on which to base future research projects focussing on end-user oriented research.

XXth TELEMAC-MASCARET User Conference, Oct 2013
Wave and hydrodynamics modelling in coastal areas is nowadays an indispensable tool for both rese... more Wave and hydrodynamics modelling in coastal areas is nowadays an indispensable tool for both research and engineering/environmental design. The selection among the various available models is equally essential and should be done cautiously, taking into consideration both the models’ capabilities and the actual modelling needs. In the above context, results of ongoing research on the comparison between TELEMAC and MIKE21 are presented in this work. The test study area is located near the Port of Brindisi in South Italy. TELEMAC simulations were performed using TOMAWAC for wave propagation and TELEMAC-2D for the hydrodynamics; MIKE21 simulations were performed using the MIKE21-SW and MIKE21-HD modules respectively. Model output is compared on the basis of wave/current fields and wave propagation along linear trajectories from the offshore to the shoreline; analysis shows an overall satisfactory agreement between the two models.

In the present paper we describe a model of the transition from a quasi static to dynamic regime ... more In the present paper we describe a model of the transition from a quasi static to dynamic regime in a granular stream. The model was developed using the results of experiments carried out on a rotating drum partially filled with sand grains or glass beads; the experiments provide information about rheology through grain velocity profiles and through the grain velocity covariance tensor. The model relies on several assumptions: we express the frictional stress component, due to prolonged contacts between particles, with a Coulomb law, assuming that the friction angle is equal to the true friction angle between the particle surfaces at contact plus the angle between the mean contact plane and the shearing plane. The difficulties involved in measuring the volume concentration of the grains with the necessary precision and the substantial impossibility of checking the results, suggest a closure based on the contact angle. We assume that the average contact angle in the frictional regime is the same as the average collisional angle in the collisional regime. The collisional contribution to the global stress is expressed as a function of the mean concentration, the local grain velocity gradient and the average contact angle between shearing layers (we implicitly assume that collisions between particles are binary and that multiple contacts between particles in movement generate friction); the kinetic contribution is not taken into account because of its minor relevance at high concentration.
The numerical model gives a satisfactory reproduction of the experimental grain velocity profiles.
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Papers by Alberto Lamberti
The numerical model gives a satisfactory reproduction of the experimental grain velocity profiles.
The numerical model gives a satisfactory reproduction of the experimental grain velocity profiles.