205 research outputs found

    Coastal sensitivity/vulnerability characterization and adaptation strategies: A review

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    Coastal area constitutes a vulnerable environment and requires special attention to preserve ecosystems and human activities therein. To this aim, many studies have been devoted both in past and recent years to analyzing the main factors affecting coastal vulnerability and susceptibility. Among the most used approaches, the Coastal Vulnerability Index (CVI) accounts for all relevant variables that characterize the coastal environment dealing with: (i) forcing actions (waves, tidal range, sea-level rise, etc.), (ii) morphological characteristics (geomorphology, foreshore slope, dune features, etc.), (iii) socio-economic, ecological and cultural aspects (tourism activities, natural habitats, etc.). Each variable is evaluated at each portion of the investigated coast, and associated with a vulnerability level which usually ranges from 1 (very low vulnerability), to 5 (very high vulnerability). Following a susceptibility/vulnerability analysis of a coastal stretch, specific strategies must be chosen and implemented to favor coastal resilience and adaptation, spanning from hard solutions (e.g., groins, breakwaters, etc.) to soft solutions (e.g., beach and dune nourishment projects), to the relocation option and the establishment of accommodation strategies (e.g., emergency preparedness)

    Utility of heavy minerals distribution and granulometric analyses in the study of coastal dynamics: Application to the littoral between SanlĂșcar de Barrameda and Rota (Cadiz, southwest Iberian Peninsula)

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    The present paper deals with grain size and heavy minerals distribution in the sandy coastal sediments of the littoral between the cities of SanlĂșcar de Barrameda and Rota. We have related these distributions to the predominant southward littoral drift and the possible source contributions, mostly represented by the Guadalquivir and Guadalete Rivers. The littoral studied is composed of fine sand in the northern sector and medium sand in its central and southern sectors. Heavy minerals were identified using X-ray analysis: the most abundant in the study area are epidote and garnet. We found that their concentrations and sizes decrease from north to south according to the coastal drift, whereas the grain morphology and the mineralogical component generally remain constant.Este trabajo trata de las distribuciones granulomĂ©trica y de minerales pesados de los sedimentos arenosos del tramo de litoral comprendido entre las ciudades de SanlĂșcar de Barrameda y Rota (suroeste de la penĂ­nsula IbĂ©rica). Se han relacionado dichas distribuciones con la deriva litoral predominante hacia el Sur y con las fuentes de aporte de sedimentos constituidas por los rĂ­os Guadalquivir y Guadalete. El litoral estudiado se caracteriza por arena fina en su parte norte y arena media en su parte central y meridional. Los minerales pesados se han identificado mediante rayos X: los mĂĄs abundantes en el ĂĄrea estudiada son epidota y granate. Se ha deducido cĂłmo sus concentraciones y tamaños disminuyen de norte a sur de acuerdo con la deriva litoral, manteniĂ©ndose el conjunto mineralĂłgico y la morfologĂ­a de los granos constante.Instituto Español de OceanografĂ­

    Characteristics and coastal effects of a destructive marine storm in the Gulf of Naples (southern Italy)

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    Destructive marine storms bring large waves and unusually high surges of water to coastal areas, resulting in significant damages and economic loss. This study analyses the characteristics of a destructive marine storm on the strongly inhabited coastal area of Gulf of Naples, along the Italian coasts of the Tyrrhenian Sea. This is highly vulnerable to marine storms due to the accelerated relative sea level rise trend and the increased anthropogenic impact on the coastal area. The marine storm, which occurred on 28 December 2020, was analyzed through an unstructured wind-wave coupled model that takes into account the main marine weather components of the coastal setup. The model, validated with in situ data, allowed the establishment of threshold values for the most significant marine and atmospheric parameters (i.e., wind intensity and duration) beyond which an event can produce destructive effects. Finally, a first assessment of the return period of this event was evaluated using local press reports on damage to urban furniture and port infrastructures

    Morphometric characteristics and internal structures of intertidal bars on the northwest Cadiz littoral (southwestern Iberian Peninsula)

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    The present paper deals with morphometric bar characteristics, to discriminate between bars that are associated with dissipative beaches and reflective ones. We shall focus on the former: their internal structures and migration rate. The beaches studied are located between the cities of Chipiona and Rota (southwest Iberian Peninsula). Dissipative beaches have a gentle slope (2 %) and are 120 m wide; moderately reflective beaches have a 5 % slope and are 90 m wide. We found that bars associated with reflective beaches are larger than those associated with dissipative beaches. On the reflective beaches, bars are convex upwards, with a seaward slope of 9° and a landward slope of 5°. On the dissipative beaches, bars have a wide, smooth crest, a seaward slope of 2°-3°, and a landward slope of 1°-2°. They are generally composed of thin sets of plane bedding laminae, parallel to the beach surface.Este trabajo pretende una descripciĂłn morfomĂ©trica de las barras intermareales para distinguir entre las asociadas a perfiles disipativos y las asociadas a perfiles reflectivos, profundizando mĂĄs en las primeras en cuanto a estructuras internas y migraciĂłn. El litoral estudiado se sitĂșa entre las ciudades de Chipiona y Rota (suroeste de la penĂ­nsula IbĂ©rica). Las playas disipativas presentan pendiente muy suave (2 %) y anchura de aproximadamente 120 m; las reflectivas tienen pendiente media del 5 % y anchura en torno a 90 m. Se ha encontrado que las barras asociadas a perfiles reflectivos son de mayores dimensiones que las asociadas a perfiles disipativos. AquĂ©llas son convexas y tienen una elevada pendiente en su lado hacia el mar (9°) y una pendiente menor en el lado hacia tierra. Las Ășltimas presentan una amplia y aplanada cresta, el lado hacia el mar tiene una pendiente de 2°-3° y el lado hacia tierra de 1°-2°. Sus estructuras internas estĂĄn constituidas por lĂĄminas paralelas a la superficie.Instituto Español de OceanografĂ­

    Interaction effects between impurities in low dimensional spin-1/2 antiferromagnets

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    We are considering the interplay between several non-magnetic impurities in the spin-1/2 Heisenberg antiferromagnet in chains, ladders and planes by introducing static vacancies in numerical quantum Monte Carlo simulations. The effective potential between two and more impurities is accurately determined, which gives a direct measure of the quantum correlations in the systems. Large effective interaction potentials are an indication of strong quantum correlations in the system and reflect the detailed nature of the valence bond ground states. In two-dimensions (2D) the interactions are smaller, but can still be analyzed in terms of valence bonds.Comment: 8 pages, 6 figures, accepted by Europhys. Lett. The latest pdf file is available at http://www.physik.uni-kl.de/eggert/papers/interact2d.pd

    Evolution of the Beach–Dune Systems in Mediterranean Andalusia (Spain) Using Two Different Proxies

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    Coastal environments are complex systems that are influenced by a combination of natural processes and human activities. Scientific interest in the effects of coastal erosion/accretion and climatic change-related processes has greatly increased in recent decades due to the growing human development along coastal areas. This paper investigates the state and evolution of beach–dune systems for the 1977–2001 and 2001–2019 periods of the Mediterranean coast of Andalusia (Spain) using two different proxies: the dune toe line, which was used to track foredunes evolution, and the high-water line, which was used to assess shoreline evolution. Results showed a general erosional behavior of the studied beach–dune systems and identified cases where the main trend was altered through human interventions. During the 1977–2001 period, foredunes essentially showed erosion (54%), accretion (24%), and stability (22%) and shorelines showed accretion (40%) and erosion and stability (34% each). During the 2001–2019 period, foredunes essentially showed erosion (42%), stability (30%), and accretion (28%), and shorelines showed erosion (40%), accretion (34%), and stability (26%). Combining the evolution classes of each proxy (dune toe/shoreline) allows the behavior of both shoreline proxies to be assessed together and provides insights additional to those derived from the use of a single proxy. In this regard, Erosion/erosion (EE) and Accretion/accretion (AA) were the most frequent behaviors in the first and second periods. The results obtained provide additional insights on the nature and drivers of coastal change that aid local coastal managers and administrations in understanding erosion processes. The method can be applied to other areas around the world where a similar database is available

    Morphological cells in the Ragusa littoral (Sicily, Italy)

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    Geomorphologic information, topographic maps (dated 1967), aerial photographs (dated 1999 and 2008), and spatial analysis procedures were used to investigate a 90 km long coastal sector in South Sicily (Italy). Information was obtained on coastal erosion/accretion areas, general sediment circulation pattern and littoral cell distribution. Human-made structures and natural headlands constituted important artificial limits dividing littoral in morphological cells. Ports and harbours were observed at Scoglitti, Punta Secca, Marina di Ragusa, Donnalucata and Pozzallo. Most of them worked as “transit” limits which interrupted predominant, eastward directed sedimentary transport, this way generating accretion in updrift (west) side of mentioned structures and erosion in downdrift (east) side. During the 1967–2008 period, about 62,000 m2 and 42,000 m2 of beach surface were respectively formed updrift of Scoglitti and Donnalucata ports. The construction of Pozzallo port gave rise to the formation of a “convergent” limit which favoured large accretion (94,000 m2) east of port structure. Most important natural structures were observed at Punta Zafaglione, P. Braccetto and Cava d’Aliga. The knowledge of littoral cell distribution acquires a great importance for appropriate management of coastal erosion processes which may be mitigated installing by-passing systems in ports and harbours and carrying out nourishment works in eroding areas, often located downdrift of ports and harbours (when these structures work as transit limits) and in central part of littoral cells (when these structures work as convergent limits)

    Coastal scenic beauty and sensitivity at the balearic islands, spain: Implication of natural and human factors

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    Coastal areas globally are facing a significant range of environmental stresses, enhanced by climate change-related processes and a continuous increase of human activities. The economic benefits of tourism are well-known for coastal regions, but, very often, conflicts arise between short-term benefits and long-term conservation goals. Among beach user preferences, five parameters of greater importance stand out from the rest, i.e., safety, facilities, water quality, litter and scenery; the latter is the main concern of this study. A coastal scenic evaluation was carried out in the Balearic Islands and focused on two major issues: coastal scenic beauty together with sensitivity to natural processes and human pressure. The archipelago is renowned as a top international coastal tourist destination that receives more than 13.5 million visitors (2019). Impressive landscape diversity makes the Balearics Islands an ideal field for this research. In total, 52 sites, respectively located in Ibiza (11), Formentera (5), Mallorca (18) and Menorca (18), were field-tested. In a first step, coastal scenic beauty was quantified using the coastal scenic evaluation system (CSES) method, based on the evaluation of 26 physical and human parameters, and using weighting matrices parameters and fuzzy logic mathematics. An evaluation index (“D”) was obtained for each site, allowing one to classify them in one of the five scenic classes established by the method. Twenty-nine sites were included in class I, corresponding to extremely attractive sites (CSES), which were mainly observed in Menorca. Several sound measures were proposed to maintain and/or enhance sites’ scenic value. In a second step, scenic sensitivity was evaluated using a novel methodological approach that makes possible the assessment of three different coastal scenic sensitivity indexes (CSSI), i.e., the natural sensitivity index NSI, the human sensitivity index HSI and the total sensitivity index TSI. Future climate change trends and projection of tourism development, studied at municipality scale, were considered as correction factors. All the islands showed places highly sensitive to environmental processes, while sensitivity to human pressure was essentially observed at Ibiza and Mallorca. Thereafter, sites were categorized into one of three sensitive groups established by the methodology. Results obtained are useful in pointing out very sensitive sceneries as well as limiting, preventing and/or anticipating future scenic degradation linked to natural and human issues

    Litter assessment on 99 Cuban beaches: a baseline to identify sources of pollution and impacts for tourism and recreation

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    Litter presence was assessed on the entire Cuban coastline, and includes 99 beaches from all Cuban regions, during field work carried out in 2012 and 2015. A standard method verified in several countries was applied, which classified beaches for nine types of litter into four grades (A-excellent to D-poor). Almost half of the Cuban beaches obtained excellent cleanliness scores, although many needed to be better managed. In this baseline, the most common types of residue were general litter (8% grade D and 35% grades B/C) and potentially harmful litter (< 68% with grade A). Resort beaches and those with international visitors showed the best litter management. Tourism Impacts seems to be related to visitor origin therefore choices to develop sustainable tourism in rural and village beaches (64%) appears low, if beach cleaning gross investment is focused on resort beaches (24%). Finally, this paper highlights geographical distribution and types of litter patterns

    Reply to J.J. Muñoz-Perez et al. Comments on “Confirmation of beach accretion by grain-size trend analysis: Camposoto beach, CĂĄdiz, SWSpain” by E. Poizot et al. (2013) Geo-Marine Letters 33(4)

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    In a novel finding for a beach environment, Poizot et al. (2013) identified an FB+ trend (sediments becoming finer, better sorted and more positively skewed upshore) on a well-developed swash bar on the upper foreshore of the Camposoto beach of Cådiz in SW Spain. In their Discussion of that paper, Muñoz-Perez et al. (2014) provide some supporting arguments and also report grain-size, beach profile and other data from nearby beaches which differ from those of Poizot and colleagues for Camposoto beach, pointing out that a trend observed on one beach may not apply to a neighbouring beach. However, even though the absolute values differ, the overall trends actually do show the same general behaviour. In our Reply to their comments, we also address some difficulties in comparing granulometric datasets generated by different analytical techniques
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