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Browsing by Author "Martins, Ana Luísa Banja"

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  • Beach volumetric analysis and wave forcing along an Irish beach system
    Publication . Martins, Ana Luísa Banja; Ferreira, Óscar; Jackson, Derek
    Five Finger Strand, a bedrock-framed beach located between Five Finger rock and the mouth of Trawbreaga Bay, Republic of Ireland, appears to experience high temporal and spatial variability in erosion and accretion because the coast is forced by multiple mechanisms that operate over different time scales (Cooper et al., 2007). To identify all states the beach can present, their frequency of occurrence and dynamics, it the study of beach profiles was implemented in which beach volumetric analysis was used to determine and predict beach evolution. Additionally incident waves were analysed and statistical analysis applied on these. Owing to data complexity, a Geographic Information System (GIS) tool – BeachPROG – was developed to facilitate data analysis. As input it uses Differential Global Positioning System (DGPS) data and outputs Digital Elevation Models (DEMs), beach volumes, profiles and respective areas and slopes, through Python script. In general, this tool revealed good results, as the data automation, visualisation, spatial consultation, and spatial analysis can be accessed in a much more intuitive way than through existing methods. Equally, this tool can serve as a methodological base for other investigations, presenting a fully commented, easy script structure that enables further modifications and/or script accretions. Data from the BeachPROG tool, were compared against hydrodynamic data at the site. The existence of variations in beach behaviour caused by wave forcing was clearly evident. However, in some cases it was equally possible to verify that even being exposed to conditions capable of causing significant changes, the beach remained stable. A deep knowledge on how waves and inlet dynamics interact with the beach, changing its behaviour, was however, not the main aim of this thesis, since the main goal was to develop and test the GIS based tool. Previous studies analysing similar forcing agents showed different beach behaviours, for the study area, indicating that further and more detailed studies must be performed.
    2014Master thesis Open access Show more