The influence of coastal dynamics on the upper limit of the Posidonia oceanica meadow     

Matteo Vacchi  Monica Montefalcone  Carlo Nike Bianchi  Carla Morri  Marco Ferrari 《Marine Ecology》2010,31(4):546-554

The recognized ecological importance of Posidonia oceanica, the most important seagrass of the Mediterranean Sea, makes it crucial to assess the state of health of its meadows, discriminating natural from anthropogenic impacts. In this paper, the hydrodynamic conditions at the upper limit of P. oceanica meadows along the Ligurian coast (NW Mediterranean Sea) were investigated. A relationship between the distance of the upper limit of the meadow from the shoreline and the morphodynamic domain of the beach (i.e. distinctive types of beach produced by the topography, wave climate and sediment composition) was found. A zonation of the state of the shallow portions of the meadows down the submerged beach profile was identified. Zone a, from the shoreline to the breaking limit, is naturally critical for the development of the meadow. Zone b, from the breaking limit to the closure depth, is subjected to natural and human impacts. Zone c, below the closure depth, is little influenced by coastal dynamics. This study quantifies for the first time how much the status of the shallow portions of P. oceanica meadows is dependent on coastal dynamics, which is important for their proper management.  相似文献   

Stochastic background of gravitational waves generated by a cosmological population of young, rapidly rotating neutron stars     

Valeria Ferrari  Sabino Matarrese  Raffaella Schneider 《Monthly notices of the Royal Astronomical Society》1999,303(2):258-264

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Human influence on seagrass habitat fragmentation in NW Mediterranean Sea     

Monica Montefalcone  Valeriano ParraviciniMatteo Vacchi  Giancarlo AlbertelliMarco Ferrari  Carla MorriCarlo Nike Bianchi 《Estuarine, Coastal and Shelf Science》2010

Habitat fragmentation in meadows of Posidonia oceanica, the most important and abundant seagrass in the Mediterranean Sea, was investigated at a region-wide spatial scale using a synthetic ecological index, the Patchiness Index (PI). We tested the hypothesis that human impacts are the major factor responsible for habitat fragmentation in P. oceanica meadows contrasting fragmentation of meadows located in “anthropized” areas with that of meadows located in areas with low anthropization and considered as virtually “natural”. We also related fragmentation of meadow with the morphodynamic state of the submerged beach (i.e. distinctive types of beach produced by the topography, the wave climate and the sediment composition) in order to investigate the influence of one natural component on the seagrass meadow seascape. Results demonstrated that fragmentation in the P. oceanica meadows is strongly influenced by the human component, being lower in natural meadows than in anthropized ones, and that it is little influenced by the morphodynamic state of the coast. The use of landscape approaches to discriminate natural disturbance from human impacts that affect seagrass meadows is thus recommended for the proper management of coastal zones.  相似文献   

An ordered probit model for seismic intensity data     

Michela?CamelettiEmail author  Valerio?De Rubeis  Clarissa?Ferrari  Paola?Sbarra  Patrizia?Tosi 《Stochastic Environmental Research and Risk Assessment (SERRA)》2017,31(7):1593-1602

Seismic intensity, measured through the Mercalli–Cancani–Sieberg (MCS) scale, provides an assessment of ground shaking level deduced from building damages, any natural environment changes and from any observed effects or feelings. Generally, moving away from the earthquake epicentre, the effects are lower but intensities may vary in space, as there could be areas that amplify or reduce the shaking depending on the earthquake source geometry, geological features and local factors. Currently, the Istituto Nazionale di Geofisica e Vulcanologia analyzes, for each seismic event, intensity data collected through the online macroseismic questionnaire available at the web-page www.haisentitoilterremoto.it. Questionnaire responses are aggregated at the municipality level and analyzed to obtain an intensity defined on an ordinal categorical scale. The main aim of this work is to model macroseismic attenuation and obtain an intensity prediction equation which describes the decay of macroseismic intensity as a function of the magnitude and distance from the hypocentre. To do this we employ an ordered probit model, assuming that the intensity response variable is related through the link probit function to some predictors. Differently from what it is commonly done in the macroseismic literature, this approach takes properly into account the qualitative and ordinal nature of the macroseismic intensity as defined on the MCS scale. Using Markov chain Monte Carlo methods, we estimate the posterior probability of the intensity at each site. Moreover, by comparing observed and estimated intensities we are able to detect anomalous areas in terms of residuals. This kind of information can be useful for a better assessment of seismic risk and for promoting effective policies to reduce major damages.  相似文献   

The relationship between the Sérsic law profiles measured along the major and minor axes of elliptical galaxies     

F. Ferrari †  H. Dottori  N. Caon  A. Nobrega  D. B. Pavani ‡ 《Monthly notices of the Royal Astronomical Society》2004,347(3):824-832

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Rotational effects on the oscillation frequencies of newly born proto-neutron stars     

V. Ferrari  L. Gualtieri  J. A. Pons  A. Stavridis 《Monthly notices of the Royal Astronomical Society》2004,350(2):763-768

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A stochastic model for the analysis of maximum daily temperature     

B.?Sirangelo  T.?Caloiero  R.?CoscarelliEmail authorView author&#;s OrcID profile  E.?Ferrari 《Theoretical and Applied Climatology》2017,128(1-2):275-289

Accurately predicting precipitation trends is vital in the economic development of a country. Ground observed data from the Nigeria Meteorological Agency (NIMET) was analyzed to study the long-term spatio-temporal trends of rainfall on annual and seasonal scales for 23 stations in Nigeria during a 40-year period spanning from 1974 to 2013. After testing the presence of autocorrelation, Mann–Kendall (modified Mann–Kendall) test was applied to non-autocorrelated (autocorrelated) series to detect the trends in rainfall data. Theil and Sen’s slope estimator test was used to find the magnitude of change over a time period. Pettitt’s test, Standard Normal Homogeneity Test, and Buishand’s test were further used to test the homogeneity of the rainfall series. The results show an increasing trend in annual rainfall; however, only nine stations have a significant increase during the period of study. On the seasonal time scale, a significant increasing trend was observed in the pre- and post-monsoon seasons, while only nine stations show a significant increasing trend in monsoon rainfall and a significant decreasing trend in the winter rainfall over the last 40 years. During the study period, 15.4 and 13.90 % increase were estimated for annual and monsoonal rainfall, respectively. Furthermore, seven stations exhibit changes in mean rainfall while majority of the stations considered (Eighteen stations) exhibit homogeneous trends in annual and seasonal rainfall over the country. The performance of the different tests used in this study was consistent at the verified significance level.  相似文献   

Drones as tools for monitoring beach topography changes in the Ligurian Sea (NW Mediterranean)     

Elisa Casella  Alessio Rovere  Andrea Pedroncini  Colin P. Stark  Marco Casella  Marco Ferrari  Marco Firpo 《Geo-Marine Letters》2016,36(2):151-163

The aim of this study was to evaluate topographic changes along a stretch of coastline in the Municipality of Borghetto Santo Spirito (Region of Liguria, Italy, north-western Mediterranean) by means of a remotely piloted aircraft system coupled with structure from motion and multi-view stereo techniques. This sector was surveyed three times over 5 months in the fall–winter of 2013–2014 (1 November 2013, 4 December 2013, 17 March 2014) to obtain digital elevation models and orthophotos of the beach. Changes in beach topography associated with storm action and human activities were assessed in terms of gain/loss of sediments and shifting of the wet–dry boundary defining the shoreline. Between the first and second surveys, the study area was hit by two storms (10–11 November 2013 and 21–22 November 2013) with waves approaching from the E–NNE, causing a shoreline retreat which, in some sectors, reached 7 m. Between the second and third surveys, by contrast, four storms (25–27 December 2013, 5–6 January 2014, 17–18 January 2014 and 6–10 February 2014) with waves propagating from the SE produced a general advancement of the shoreline (up to ~5 m) by deposition of sediments along some parts of the beach. The data also reflect changes in beach topography due to human activity during the 2013 fall season, when private beach managers quarried ~178 m³ of sediments on the emerged beach near the shoreline to accumulate them landwards. The results show that drones can be used for regular beach monitoring activities, and that they can provide new insights into the processes related to natural and/or human-related topographic beach changes.  相似文献   

Calcretes and travertines from the Palaeocene Itaboraí Basin as evidence of the early evolution of the Southeastern Brazil Continental Rift     

Paula Braga Adler  Luiz Fernando De Ros  Ktia Leite Mansur  Andr Luiz Ferrari  Luiz Alberto Fernandes  Alcides Nbrega Sial 《Sedimentology》2021,68(1):477-511

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Springtime changes in snow chemistry lead to new insights into mercury methylation in the Arctic     

Catherine Larose  Aurélien Dommergue  Martine De Angelis  Bernard Averty  Nicolas Soumis  Christophe Ferrari 《Geochimica et cosmochimica acta》2010,74(22):6263-6275

Seasonal snow is an active media and an important climate factor that governs nutrient transfer in Arctic ecosystems. Since the snow stores and transforms nutrients and contaminants, it is of crucial importance to gain a better understanding of the dynamics of contaminant cycling within the snowpack and its subsequent release to catchments via meltwater. Over the course of a two-month field study in the spring of 2008, we collected snow and meltwater samples from a seasonal snowpack in Ny-Ålesund, Norway (78°56′N, 11°52′E), which were analyzed for major inorganic ions and some organic acids, as well as total, dissolved, bioavailable mercury (THg, DHg, BioHg, respectively) and monomethylmercury (MMHg) species. We observe a seasonal gradient for ion concentrations, with surface samples becoming less concentrated as the season progressed. A significant negative correlation between BioHg and MMHg was observed in the snowpack. MMHg was positively and significantly correlated to methanesulfonate concentrations. Based on these results, we propose a new model for aerobic methylation of mercury involving species in the dimethylsulfoniopropionate cycle.  相似文献