41 research outputs found
An Interactive WebGIS Framework for Coastal Erosion Risk Management
The Italian coastline stretches over about 8350 km, with 3600 km of beaches, representing a significant resource for the country. Natural processes and anthropic interventions keep threatening its morphology, moulding its shape and triggering soil erosion phenomena. Thus, many scholars have been focusing their work on investigating and monitoring shoreline instability. Outcomes of such activities can be largely widespread and shared with expert and non-expert users through Web mapping. This paper describes the performances of a WebGIS prototype designed to disseminate the results of the Italian project Innovative Strategies for the Monitoring and Analysis of Erosion Risk, known as the STIMARE project. While aiming to include the entire national coastline, three study areas along the regional coasts of Puglia and Emilia Romagna have already been implemented as pilot cases. This WebGIS was generated using Free and Open-Source Software for Geographic information systems (FOSS4G). The platform was designed by combining Apache http server, Geoserver, as open-source server and PostgreSQL (with PostGIS extension) as database. Pure javascript libraries OpenLayers and Cesium were implemented to obtain a hybrid 2D and 3D visualization. A user-friendly interactive interface was programmed to help users visualize and download geospatial data in several formats (pdf, kml and shp), in accordance with the European INSPIRE directives, satisfying both multi-temporal and multi-scale perspectives. © 2021 by the authors. Licensee MDPI, Basel, Switzerlan
Exploiting remote imagery in an embayed sandy beach for the validation of a runup model framework
International audienceStorm surge and wave runup are key determinants of the potential for beach overwashing during storm events. However, the prediction and quantification of wave runup on embayed beaches is strongly influenced by particular characteristics (e.g., irregular morphology, low tides, absence of swell, etc.) which differ from those on open beaches, and have rarely been investigated in literature. In the present paper, a model framework aimed at predicting wave-induced runup on an embayed sandy beach is validated by means of measurements derived from a video-monitoring station, recently installed in South Italy, during two storm events in 2016. The numerical approach employs MeteOcean forecasted waves within SWAN and SWASH models (in both 2-d and 1-d mode). The combination of multibeam and d-RTK surveys with Unmanned Aerial Vehicle (UAV) imagery provides high resolution depth grid (m 0.015), particularly required in shallow waters, where wave hydrodynamics is highly influenced by the bottom. The results show and discuss the agreement between video measurements and 2-d predictions of runup. A sensitivity analysis of the Manningfls roughness factor is needed in 1-d simulations. The accuracy of the empirical formulas in predicting wave runup in an embayed beach is also investigated , showing mainly an overestimation of the observations
Groundwater Levels in a Drained Beach in Long and Short Waves Conditions
none5noneFischione, Piera; Pasquali, Davide; Di Nucci, Carmine; Di Risio, Marcello; Saponieri, AlessandraFischione, Piera; Pasquali, Davide; Di Nucci, Carmine; Di Risio, Marcello; Saponieri, Alessandr
new coastal video monitoring system achievement and development
A new coastal video monitoring system for Apulia region, southeast of Italy, is under development. It is composed of visible and thermal streams and featured to be included in a wider meteo-oceanographic monitoring network. The system is designed for use on sandy beaches. The regional Basin Authority (AdBP) through previous field campaigns has identified for long-term monitoring purposes two hotspots, prone to erosion and flooding: Torre Canne (Fasano, BR) and Torre Lapillo (Porto Cesareo, LE), facing the Adriatic and Ionian seas, respectively. This paper presents the actual architecture and some initial findings of its implementation aiming at a complete automatic analysis of morphological features and hydrodynamic studies, mainly focused in swash zone
WALOWA (wave loads on walls) : large-scale experiments in the delta flume
Overtopping wave loads on vertical structures on top of a dike have been investigated in several small scale experiments in the past. A large-scale validation for a mild foreshore situation is still missing. Hence the WALOWA experimental campaign was carried out to address this topic. In the present paper the objectives of the WALOWA project are outlined in detail, the model and measurement set-up described and the test program presented. Furthermore, preliminary results featuring a single 1000 irregular waves test of the test program are highlighted. This includes the study of the mild and sandy foreshore evolution by comparing profiles before and after the test execution. The profile measurements are obtained with a mechanical profiler. The wave parameters offshore and at the dike toe are numerically simulated using a SWASH model. The numerical results are validated against the measurements. Finally, the force and pressure time series of the waves impacting against the wall are processed and filtered. The load cell measurements and the time series of integrated pressures are compared to each other and for each impact event the maximum force is derived.Hydraulic Structures and Flood RiskEnvironmental Fluid Mechanic
Overtopped wave loads on walls (WALOWA) : numerical and physical modelling of large-scale experiments in the delta flume
Laboratory Investigation on the Evolution of a Sandy Beach Nourishment Protected by a Mixed Soft–Hard System
A new experimental campaign on a 2D movable-bed physical model, reproducing a typical nourishment sandy beach profile, is being carried out in the wave flume of the Laboratory of Coastal Engineering at Politecnico di Bari (Bari, Italy). The main aim is to assess the short-term evolution of a sandy beach nourishment, relying on a mixed solution built on the deployment of a Beach Drainage System (BDS) and a rubble-mound detached submerged breakwater. This paper aims at illustrating the experimental findings. Tests presented herein deal with both unprotected and protected configurations, focusing on the hydrodynamic and morphodynamic processes under erosive conditions. Results show that, with respect to the unprotected conditions, BDS reduces the shoreline retreat and the beach steepen within swash and surf zone as well. Moreover, a reduction of net sediment transport rate is observed. When BDS is coupled with the submerged sill, a reversal of the prevalent direction of the net sediment transport seaward occurs offshore the sheltered region. Less considerable positive effects on shoreline retreat are induced by the submerged structure, whereas the mean beach slope remains quite stable. Secondary effects of drain on the submerged sill performance are also highlighted. BDS reduces wave-induced setup on beach, by mitigating the mean water level raising, typically experienced by such structures
Influenza dei processi di infiltrazione sulla stabilitĂ delle spiagge
Il presente lavoro mostra i principali risultati ottenuti dalle prove sperimentali condotte in laboratorio su di un sistema di drenaggio delle spiagge. Le indagini sperimentali sono state effettuate su un modello in piccola scala e su uno a scala prototipo, permettendo di valutare gli effetti del dreno sui moti di infiltrazione e sui processi di idrodinamica che di morfodinamica nearshore. I risultati ottenuti, ancorchè non definitivi, mostrano anche alcuni favorevoli effetti del dreno sulla morfodinamica della zona di riva
Analisi sperimentale di una spiaggia in presenza di un sistema di drenaggio
Il sistema di drenaggio delle spiagge (Beach Drainage System, BDS) è un’opera a basso impatto ambientale di ausilio alle tradizionali tecniche di difesa costiera. Esso favorisce l’assorbimento dei flussi di infiltrazione attraverso l’abbassamento artificiale del livello di saturazione all’interno spiaggia. Il dreno, installato al di sotto della linea di saturazione, interagisce con l’idrodinamica della zona di swash e modifica i processi morfodinamici promuovendo la stabilizzazione dei sedimenti che, in condizioni naturali, verrebbero trasportati verso largo nella fase di back-wash dell’onda. Un programma di prove sperimentali in larga scala è stato condotto presso il laboratorio Grosser WellenKanal (GWK) di Hannover, Germania, su un modello bidimensionale del sistema di drenaggio. L’obiettivo di tale ricerca è stato quello di comprendere l’influenza del drenaggio sui processi idrodinamici e morfodinamici nella zona di riva.
Nel presente lavoro l’attenzione è focalizzata sugli aspetti idrodinamici. In particolare sono analizzate le variazioni della linea di staurazione in condizioni naturali (non drenate) e drenate, gli effetti del drenaggio sul set-up e sui flussi di ritorno