Search results for "shoreline"

Random wave run-up with a physically-based Lagrangian shoreline model

2014

Abstract In the present paper the run-up of random waves was calculated by means of a numerical method. In situ measurements based on a video imaging technique have been used for the validation of the present numerical model. The on-site run-up measurements have been carried out at Lido Signorino beach, near Marsala, Italy,along a transect, normal to the shore. A video camera and a linear array of rods have been used to obtain field data. Numerical simulations with a 1DH Boussinesq-type of model for breaking waves which takes into account the wave run-up by means of a Lagrangian shoreline model have been carried out. In such simulations random waves of given spectrum have been propagated in…

A Shoreline model for breaking waves

2011

In order to simulate the wave motion and, in turn, the flow, within the nearshore region, in the last decades the derivation and the application of depth-integrated type of models have been widely investigated and developed. However, in such models, the problems of facing wave breaking and the moving shoreline are not trivial and therefore several approaches have been proposed. About wave breaking, approaches both based on the adoption of an artificial eddy viscosity Zelt (1991) and on the concept of roller Veeramony (2000), Karambas (2003), Musumeci (2005) have been implemented. As regards the shoreline boundary condition, a couple of numerical techniques have been mainly adopted, namely t…

Shoreline Evolution and Environmental Changes at the NW Area of the Gulf of Gela (Sicily, Italy)

2021

Coastal areas are among the most biologically productive, dynamic and valued ecosystems on Earth. They are subject to changes that greatly vary in scale, time and duration and to additional pressures resulting from anthropogenic activities. The aim of this work was to investigate the shoreline evolution and the main environmental changes of the coastal stretch between the towns of Licata and Gela (in the Gulf of Gela, Sicily, Italy). The methodology used in this work included the analysis of: (i) shoreline changes over the long- and medium-term periods (1955–2019 and 1989–2019, respectively), (ii) dune system fragmentation and (iii) the impact of coastal structures (harbours and breakwaters…

Coupling a hydro-maritime model and remotely sensed techniques to assess the shoreline positioning uncertainty: the Marsala coast study case

2010

The severe erosion phenomena affecting the Mediterranean coasts are strictly related to geophysical characteristics and socio-economic pressures. This suggests the need of monitoring and modelling the phenomenon in order to quantify its strength. In fact, the shoreline position, as well as its temporal evolution, provides important information for designing defence structures and for the development of a coastal management plan. The shoreline has a dynamic nature as it changes both in the short and long period. Those changes are caused by geo-morphological (e.g. bars and barrier island development etc.) and hydrodynamic (wave motion, tides and flows) processes, as well as by sudden and fast…

Field run-up measurements: Calibration of a physically based lagrangian shoreline model

2012

In the present contribution a measurement technique based on video imaging has been selected for the assessment of the maximum run-up. Such measurements have been used for the calibration of a numerical model and of an empirical formulation. The on-site run-up measurements have been carried out at “Lido Signorino” beach, near Marsala, Italy. The positions of the swash have been localized on a transect, normal to the shore, constituted by stakes placed at 0.5 m intervals each other. The video camera was placed orthogonally to the line of the stakes. For the numerical simulations a 1DH Boussinesq-type of model for breaking waves has been applied which takes into account the wave run-up by a L…

CRITICAL ANALYSIS OF SHORELINE LOCALIZATION METHODS BY MEANS OF AERIAL OR SATELLITE IMAGERY ON MEDITERRANEAN SANDY BEACHES

2013

Shoreline localization is fundamental for designing and planning shore protection works as well as for managing and monitoring various anthropic activities along the coast. The sea-land boundary, however, changes continually with time because of waves and tides, which makes the shoreline detection complex and dubious and the boundary line finally assumed can only be conventional. In the last few decades the use of several geomorphologic indicators has been proposed, such as the berm above sea level, the groundwater exit point, historic high tide levels, etc., but the aim has not been achieved yet. Among the methods used, analysis of aerial and satellite imagery is common, in particular when…

Diachronic analysis of the shoreline in San Leone beach (Agrigento-Sicily)

2015

In the last century the Italian coasts and the Sicilian ones, suffered of a radical transformation due to a large population increase. The coastal areas settlements is related to the growth of the industrial activities, the development of tourism and the associated expansion of the road network. The development of these activities, have encouraged the rapid growth of populated areas without adequate urban planning and environmental criteria. In many cases, private houses, hotels, roads or railways covered or occupied entire coastal areas, such as destroying several kilometers of backshore dune systems. In addition, the construction or expansion of ports and fishing marinas effected the natu…

Morphodinamic evolution: assessment of the shoreline position

2010

The mediterranean coast of Andalusia (sw spain): the impacts of human coastal structures

2015

Spanish coasts, especially the Andalusia Mediterranean one, were affected over time by progressive urbanization and associated construction of defense structures. Such structures protected small coastal sectors but at places triggered processes of coastal erosion and associated degradation of habitats and ecosystems. A correct management of coastal areas must be based on the monitoring of coastal evolution and human pressure. A useful tool to evaluate the level of human anthropization is the estimation of the "Coastal Armouring", e.g. the quantification of coastal defense structures, infrastructures, ports, etc. In this study, available aerial photographs and satellite images from 1956 to 2…

Medium-term shoreline evolution of the mediterranean coast of Andalusia (SW Spain)

2015

Coastal environment is a dynamic system in which numerous natural processes are continuously actuating and interacting among them. As a result, geomorphologic, physical and biological characteristics of coastal environments are constantly changing. Such dynamic balance is nowadays seriously threatened by the strong and increasing anthropic pressure that favors erosion processes, and the associated loss of environmental, ecologic and economic aspects. Sandy beaches are the most vulnerable environments in coastal areas. The aim of this work was to reconstruct the historical evolution of the Mediterranean coastline of Andalusia, Spain. The investigated area is about 500 km in length and includ…