Loading...
6 results
Search Results
Now showing 1 - 6 of 6
- Beach erosion and recovery during consecutive storms at a steep-sloping, meso-tidal beachPublication . Vousdoukas, Michalis; Almeida, Luis Pedro; Ferreira, ÓscarThis study analyses beach morphological change during six consecutive storms acting on the meso-tidal Faro Beach (south Portugal) between 15 December 2009 and 7 January 2010. Morphological change of the sub-aerial beach profile was monitored through frequent topographic surveys across 11 transects. Measurements of the surf/swash zone dimensions, nearshore bar dynamics, and wave run-up were extracted from time averaged and timestack coastal images, and wave and tidal data were obtained from offshore stations. All the information combined suggests that during consecutive storm events, the antecedent morphological state can initially be the dominant controlling factor of beach response; while the hydrodynamic forcing, and especially the tide and surge levels, become more important during the later stages of a storm period. The dataset also reveals the dynamic nature of steep-sloping beaches, since sub-aerial beach volume reductions up to 30m3/m were followed by intertidal area recovery (–2
- Introduction to RISC-KIT: resilience-increasing strategies for coastsPublication . Van Dongeren, Ap; Ciavola, Paolo; Martinez, Grit; Viavattene, Christophe; Bogaard, Tom; Ferreira, Óscar; Higgins, Ruth; McCall, RobertIn this paper an introduction is provided to the RISC-KIT project’s goals, products and applications, which is the subject of this Special Issue. Subsequent papers provide the details on the developed tools and their application on ten case study sites in Europe.
- Historical analysis of storm events: case studies in France, England, Portugal and ItalyPublication . Garnier, E.; Ciavola, P.; Spencer, T.; Ferreira, Óscar; Armaroli, C.; McIvor, A.An historical analysis of the occurrence of storms and their damage intensity is presented. The work analysed historical large-scale events from The Middle Ages to the 1960s at case study sites along the coasts of North Norfolk (UK); Charente-Maritime and Vendée (France); Cinque Terre-Liguria coast (Italy); Emilia-Romagna coast (Italy) and Ria Formosa (Portugal). The work presented here used a database of events built by the RISC-KIT project, including the characteristics of the storms as well as recorded human impacts. Historical records can provide an important test bed to complement the statistical analysis of the return period of events based on measurements and provide important indicators of past events and their impact that are no longer within the historical memories of resident populations and coastal managers.
- Modelling storm-induced beach morphological change in a meso-tidal, reflective beach using XBeachPublication . Vousdoukas, M. I.; Almeida, L. P.; Ferreira, ÓscarExtensive XBeach testing took place against field topographic and bathymetric measurements of storm morphological impact at the mesotidal, reflective Faro Beach (S. Portugal). Five monitored events have been selected for XBeach calibration and sets of runs for 768 different set-ups, showed that alongshore profile morphology variations even for the same site, may require different calibration settings, in order to achieve optimal performance. XBeach performed better with higher facua and wetslope values at the reflective parts of the study area and with lower values at the less steep ones. Model sensitivity to calibration settings appeared to increase with beach slope; while the majority of the tested set-ups resulted in negative Brier Skill Scores (BSS). The main discrepancies compared to the field measurements were related to the overestimation of berm erosion and the intense avalanching/beach scarp formation; which rarely occur at the study site. Moreover, the simulations resulted in morphological change within a narrower profile section than observed; and did not accurately simulate offshore bar formation. The study highlights that predicting beach profile morphodynamic response during storm events at steep reflective beaches with XBeach may be more difficult than at intermediate beaches. However, the results can be satisfactory after proper calibration and for the present study the optimal cases resulted in BSS of the range 0.2-0.7. The best performance was obtained by deactivating long wave stirring, wave-current interaction and equilibrium sediment computation (lws=0, wci=0, turb=0, respectively); keeping directional spreading of long waves and groundwater flow on (nspr=1, gwf=1, respectively); and using the lower morfac, facua and wetslope parameters (at the present case morfac=5, facua=0.1 and wetslope=0.2).
- Storm impacts along European coastlines. Part 2: lessons learned from the MICORE projectPublication . Ciavola, Paolo; Ferreira, Óscar; Haerens, Piet; Van Koningsveld, Mark; Armaroli, ClaraThis paper describes the MICORE approach to quantify for nine field sites the crucial storm related physical hazards (hydrodynamic as well as morphodynamic) in support of early warning efforts and emergency response. As a first step historical storms that had a significant morphological impact on a representative number of sensitive European coastal stretches were reviewed and analysed in order to understand storm related morphological changes and how often they occur around Europe. Next, an on-line storm prediction system was set up to enable prediction of storm related hydro- and morphodynamic impacts. The system makes use of existing offthe- shelf models as well as a new open-source morphological model. To validate the models at least one year of fieldwork was done at nine pilot sites. The data was safeguarded and stored for future use in an open database that conforms to the OpenEarth protocols. To translate quantitative model results to useful information for Civil Protection agencies the Frame of Reference approach (Van Koningsveld et al., 2005, 2007) was used to derive Storm Impact Indicators (SIIs) for relevant decision makers. The acquired knowledge is expected to be directly transferred to the civil society trough partnerships with end-users at the end of the MICORE project.
- Storm impacts along European coastlines. Part 1: The joint effort of the MICORE and ConHaz ProjectsPublication . Ciavola, Paolo; Ferreira, Óscar; Haerens, Piet; Van Koningsveld, Mark; Armaroli, Clara; Lequeux, QuentinThe current paper discusses the topic of marine storm impact along European coastlines, presenting results from two FP7 Projects currently focusing on this topic, one working on the physical aspects of the problem (MICORE) and the other one on the socio-economic implications (ConHaz). The MICORE Project aims to provide on-line predictions of storm-related physical hazards (hydrodynamic as well as morphodynamic). The ConHaz Project addresses the socio-economic implications should these (or other) hazards actually materialize. Together these projects aim to deliver crucial information for emergency response efforts, while realizing the practical limitations for information processing and dissemination during crisis situations. The MICORE Project has developed and demonstrated on-line tools for reliable predictions of the morphological impact of marine storm events in support of civil protection mitigation strategies. The project specifically targeted the development of early warning and information systems to support short term emergency response in case of an extreme storm event. The current paper discusses in detail the outcome of an activity of databasing historical storm data. No clear changes in storminess were observed, except for some storm proxies (e.g. surges) and only at some locations (e.g. northern Adriatic, southern Baltic, etc.). The ConHaz Project undertook a desktop study of the methods normally used for evaluating the impact of marine storms and the associated coastal hazards considering direct costs, costs due to disruption of production processes, indirect costs, intangible costs, and costs of adaptation and mitigation measures. Several methods for cost estimation were reviewed. From the review it emerged that normally end-users only evaluate direct costs after the storms, while the cost of adaptation and mitigation measures is only done strategically in the context of Integrated Coastal Zone Management plans. As there is no standardized method for cost evaluations in this field, it is suggested that clear guidelines should be produced on the basis of simplicity for use by end-users. The integration between historical databases of the physical parameters of storms and detailed cost evaluation information would support the development of a knowledge background in end-users and justify the development of adaptation strategies.