Journal of Coastal Research, Special Issue No. 61, 2011 303 Journal of Coastal Research SI 61 303-308 MCRR3-2010 Conference Proceedings 2011 Estimating Coastal Vulnerability in a Meso-Tidal Beach by Means of Quantitative and Semi-Quantitative Methodologies Gianluigi Di Paola 1 , Javier Iglesias 2 , Gérman Rodríguez 3 , Guido Benassai 4 , Pietro Aucelli 5 and Gerardo Pappone 6 ABSTRACT DI PAOLA, G., IGLESIAS, J., RODRÍGUEZ, G., BENASSAI, G., AUCELLI, P and PAPPONE, G., 2011. Estimating Coastal Vulnerability in a Meso-Tidal Beach by Means of Quantitative and Semi-Quantitative Methodologies. In: Micallef, A. (ed.), MCRR3-2010 Conference Proceedings, Journal of Coastal Research, Special Issue, No. 61, pp. 303-308. Grosseto, Tuscany, Italy, ISSN 0749-0208. The main goal of this study is to estimate the coastal vulnerability on a stretch of coastline by using two different methodologies and to check if both methodologies give rise to similar results or if notably dissimilar assessments are obtained. To reach the above mentioned objective, a new experimental methodology (Benassai et al, 2009) based on inundation of the inshore land and the well known USGS methodology (Gornitz et al, 1994) are applied and compared. In the first approach, a new parameter, named as impact index, is calculated by using wave climate and geomorphologic data. In general, impact index depends on run-up height, seasonal and long term erosion index and the efficiency of existing structures for coastal defence. The relative value of this parameter is contrasted with that of the often used coastal vulnerability index, CVI, which includes geological and physical variables. The application of these methods gives rise to significantly different levels of vulnerability for the same zone. This situation must be attributed mainly to the distinctive nature of the used methods. Thus, taking into account the results, it is remarked that the procedure to choose a methodology for assessing the vulnerability of a given coastal zone must be based on the available information and on the characteristics of the zone. Furthermore, the use of the same method to do risk and vulnerability comparisons is recommended. ADDITIONAL INDEX WORDS: coastal vulnerability, geomorphologic risk, natural hazards. INTRODUCTION It is a well known fact that coasts are highly dynamic and geomorphologic complex systems, which respond in a non- linear manner to extreme events. DOI: 10.2112/SI61-001.1 received XX; accepted XX ©Coastal Education & Research Foundation 2011 In addition, the impacts of climate change will include possible increases to sea surface temperatures, variability in the patterns of rainfall and runoff, changes in frequency, intensity and duration of storms. In light of this, the coast is regarded as one of the most vulnerable areas on the planet and, accordingly, scientific community has significantly increased the activity on the development of techniques to assess its vulnerability. The evaluation of coastal vulnerability is a controversial topic in the coastal engineering field and a vast literature www.cerf-jcr.org 3 Departamento de Fisica, Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain Tel: + (34) 928 451289 grodriguez@dfis.ulpgc.es 4 Dipartimento di Scienze applicate, Università degli Studi di Napoli “Parthenope”, Napoli, Italy Tel: + (39) 081 5476590 guido.benassai@uniparthenope.it 5 Dipartimento di Scienze per l’Ambiente, Università degli Studi di Napoli “Parthenope”, Napoli, Italy Tel: + (39) 081 5476611 pietro.aucelli@uniparthenope.it 6 Dipartimento di Scienze per l’Ambiente, Università degli Studi di Napoli “Parthenope”, Napoli, Italy Tel: + (39) 081 5476663 gerardo.pappone@uniparthenope.it 1 Dipartimento di Scienze e Tecnologie per l’Ambiente e il Territorio, Università degli Studi del Molise, Pesche (IS), Italy Tel: + (39) 0874 404168 gianluigi.dipaola@unimol.it 2 Dipartimento de Cartografía, Y Expresión Gráfica en la Ingeniería, Universidad de Las Palmas de Canaria Tel: + (34) 928 451970 figlesias@dc.egiulpgc.es