Probabilistic modelling of macroseismic attenuation and forecast of damage scenarios     

Renata Rotondi  Elisa Varini  Carla Brambilla 《Bulletin of Earthquake Engineering》2016,14(7):1777-1796

According to the idea now widespread that macroseismic intensity should be expressed in probabilistic terms, a beta-binomial model has been proposed in the literature to estimate the probability of the intensity at site in the Bayesian framework and a clustering procedure has been adopted to define learning sets of macroseismic fields required to assign prior distributions of the model parameters. This article presents the results concerning the learning sets obtained by exploiting the large Italian macroseismic database DBM1I11 (Locati et al. in DBMI11, the 2011 version of the Italian Macroseismic Database, 2011. http://emidius.mi.ingv.it/DBMI11/) and discusses the problems related to their use in probabilistic modelling of the attenuation in seismic regions of the European countries partners of the UPStrat-MAFA project (2012), namely South Iceland, Portugal, SE Spain and Mt Etna volcano area (Italy). Anisotropy and the presence of offshore earthquakes are some of the problems faced. All the work has been carried out in the framework of the Task B of the project.  相似文献   

Multi-nest high-resolution model of submesoscale circulation features in the Gulf of Taranto   总被引：1，自引：1，他引：0  

Francesco Trotta  Nadia Pinardi  Elisa Fenu  Alessandro Grandi  Vladyslav Lyubartsev 《Ocean Dynamics》2017,67(12):1609-1625

Recent oceanographic field measurements and high-resolution numerical modelling studies have revealed intense, transient, submesoscale motions characterised by a horizontal length scale of 100–10,000 m. This submesoscale activity increases in the fall and winter when the mixed layer (ML) depth is at its maximum. In this study, the submesoscale motions associated with a large-scale anticyclonic gyre in the central Gulf of Taranto were examined using realistic submesoscale-permitting simulations. We used realistic flow field initial conditions and multiple nesting techniques to perform realistic simulations, with very-high horizontal resolutions (> 200 m) in areas with submesoscale variability. Multiple downscaling was used to increase resolution in areas where instability was active enough to develop multi-scale interactions and produce 5-km-diameter eddies. To generate a submesoscale eddy, a 200-m resolution was required. The submesoscale eddy was formed through small-scale baroclinic instability in the rim of a large-scale anticyclonic gyre leading to large vertical velocities and rapid restratification of the ML in a time-scale of days. The submesoscale eddy was confirmed by observational data from the area and we can say that for the first time we have a proof that the model reproduces a realistic submesoscale vortex, similar in shape and location to the observed one.  相似文献   

Robust regression based on shrinkage with application to Living Environment Deprivation     

Cabana  Elisa  Lillo  Rosa E.  Laniado  Henry 《Stochastic Environmental Research and Risk Assessment (SERRA)》2020,34(2):293-310

Stochastic Environmental Research and Risk Assessment - A robust estimator is proposed for the parameters that characterize the linear regression problem. It is based on the notion of shrinkages,...  相似文献   

Modelling background seismicity components identified by nearest neighbour and stochastic declustering approaches: the case of Northeastern Italy     

Benali  Amel  Peresan  Antonella  Varini  Elisa  Talbi  Abdelhak 《Stochastic Environmental Research and Risk Assessment (SERRA)》2020,34(6):775-791

Stochastic Environmental Research and Risk Assessment - An adequate characterization of the temporal features of background seismicity, namely after removal of temporally and spatially clustered...  相似文献   

Responses of humpback whales to a changing climate in the Southern Hemisphere: Priorities for research efforts     

Jan-Olaf Meynecke  Elisa Seyboth  Jasper De Bie  Jan-Lukas Menzel Barraqueta  Abdoulkadri Chama  Subhra Prakash Dey  Serena Blyth Lee  Vivitskaia Tulloch  Marcello Vichi  Ken Findlay  Alakendra Narayan Roychoudhury  Brendan Mackey 《Marine Ecology》2020,41(6):e12616

Globally, baleen whales were severely depleted by historic whaling. Recovering populations have been observed to alter their behaviour. These changes have been attributed to climate change in some cases and raise concerns over the successful recovery of baleen whale populations. Current data-driven statistical habitat and behavioural models have proven useful for addressing questions of whale distribution changes within their limitations. Given observed changes in oceanic conditions, a new approach to managing baleen whale population recovery is necessary. Model predictions of future whale movements and distributions under climate change scenarios are vital to enable adequate conservation management. This paper presents a new perspective on understanding the impacts of climate change on humpback whales, arguing the need for a system-based multidisciplinary research approach. Our approach includes coupled, mechanistic models based upon robust ecological principles, and integrates key physical, biogeochemical, biological and ecological modules to address long-term changes associated with climate change. To illustrate the need for this system-based multidisciplinary approach, we focus on Southern Hemisphere humpback whales, the recovery of which may be impacted by rapid changes in habitat conditions brought about by anthropogenic climate change.  相似文献   

Trophic modeling of the Northern Humboldt Current Ecosystem, Part I: Comparing trophic linkages under La Niña and El Niño conditions   总被引：1，自引：1，他引：0  

Jorge Tam  Marc H. Taylor  Vernica Blaskovic  Pepe Espinoza  R. Michael Balln  Erich Díaz  Claudia Wosnitza-Mendo  Juan Argüelles  Sara Purca  Patricia Ayn  Luis Quipuzcoa  Dimitri Gutirrez  Elisa Goya  Noemí Ochoa  Matthias Wolff 《Progress in Oceanography》2008,79(2-4):352

The El Niño of 1997–98 was one of the strongest warming events of the past century; among many other effects, it impacted phytoplankton along the Peruvian coast by changing species composition and reducing biomass. While responses of the main fish resources to this natural perturbation are relatively well known, understanding the ecosystem response as a whole requires an ecotrophic multispecies approach. In this work, we construct trophic models of the Northern Humboldt Current Ecosystem (NHCE) and compare the La Niña (LN) years in 1995–96 with the El Niño (EN) years in 1997–98. The model area extends from 4°S–16°S and to 60 nm from the coast. The model consists of 32 functional groups of organisms and differs from previous trophic models of the Peruvian system through: (i) division of plankton into size classes to account for EN-associated changes and feeding preferences of small pelagic fish, (ii) increased division of demersal groups and separation of life history stages of hake, (iii) inclusion of mesopelagic fish, and (iv) incorporation of the jumbo squid (Dosidicus gigas), which became abundant following EN. Results show that EN reduced the size and organization of energy flows of the NHCE, but the overall functioning (proportion of energy flows used for respiration, consumption by predators, detritus and export) of the ecosystem was maintained. The reduction of diatom biomass during EN forced omnivorous planktivorous fish to switch to a more zooplankton-dominated diet, raising their trophic level. Consequently, in the EN model the trophic level increased for several predatory groups (mackerel, other large pelagics, sea birds, pinnipeds) and for fishery catch. A high modeled biomass of macrozooplankton was needed to balance the consumption by planktivores, especially during EN condition when observed diatoms biomass diminished dramatically. Despite overall lower planktivorous fish catches, the higher primary production required-to-catch ratio implied a stronger ecological impact of the fishery and stresses the need for precautionary management of fisheries during and after EN. During EN energetic indicators such as the lower primary production/total biomass ratio suggest a more energetically efficient ecosystem, while reduced network indicators such as the cycling index and relative ascendency indicate of a less organized state of the ecosystem. Compared to previous trophic models of the NHCE we observed: (i) a shrinking of ecosystem size in term of energy flows, (ii) slight changes in overall functioning (proportion of energy flows used for respiration, consumption by predators and detritus), and (iii) the use of alternate pathways leading to a higher ecological impact of the fishery for planktivorous fish.  相似文献   

Marine Metapopulations     

Celeste Benham  Alison M. Cawood  Geoffrey S. Cook  Ange Darnell  Peter C. Davison  Miriam C. Goldstein  Ayana Elizabeth Johnson  Talina Konotchick  Elisa M. Maldonado  Alexis L. Pasulka  Jennifer C. Prairie  Serena M. Moseman  Vera Tai  Christina A. Tanner  Tali Vardi  Tara S. Whitty  & Lisa A. Levin 《Marine Ecology》2008,29(2):319-320

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Changes in biomass structure and trophic status of the plankton communities in a highly dynamic ecosystem (Gulf of Venice,Northern Adriatic Sea)     

Alessandra Pugnetti  Anna Maria Bazzoni  Alfred Beran  Fabrizio Bernardi Aubry  Elisa Camatti  Mauro Celussi  Joan Coppola  Erica Crevatin  Paola Del Negro  Alessandro Paoli 《Marine Ecology》2008,29(3):367-374

The changes in the plankton biomass structure in relation to nutrient inputs were studied in the Gulf of Venice (Northern Adriatic Sea), an area characterized by a very marked trophic state variability. The investigation was carried out at two stations, in March, May and July 2005 and 2006, considering the whole water column. The size structure (from picoplankton to mesozooplankton) of both autotrophs and heterotrophs was analysed. Signals of diluted waters and nutrient inputs were more marked in 2005 than in 2006. In 2005, the total plankton biomass was almost double (87 ± 37 μg·C·l^?1) that in 2006 (44 ± 26 μg·C·l^?1). The variations were determined mainly by phytoplankton, with a 70% decrease, and a shift from a community dominated by microphytoplankton (49 ± 12%) in 2005 to one dominated by bacteria (43 ± 11%) in 2006 was observed. The relationship between the heterotrophic (H) and autotrophic (A) biomass indicated a rapid decline of the H/A ratio with increasing phytoplankton biomass. This study, although temporally limited, is consistent with the results reported for other marine environments and it seems to confirm the importance of nutrient inputs in structuring the biomass of plankton community.  相似文献   

Conservation and management of ecological systems in a changing California     

Elisa Barbour  Lara M. Kueppers 《Climatic change》2012,111(1):135-163

Climate change in California is altering habitat conditions for many species and exacerbating stress from other factors such as alien invasive species, pollution, and habitat fragmentation. However, the current legal and planning framework for species protection does not explicitly take climate change into account. The regulatory framework is primarily reactive, kicking in only after species’ health is gravely threatened. Neither federal nor state regulations require forward-looking, climate-sensitive species or ecosystem protection plans. Habitat planning is poorly funded and often piecemeal. In this context, the wrong lands may be protected, with development allowed to occur in areas that would be most beneficial for species conservation in the future. A more forward-looking approach to habitat conservation is needed, one based on a statewide strategy to identify and protect critical habitat areas, including corridors to enable species migration. The approach would also require development of assessment indicators and assistance strategies not dependent on current habitat structure, and a governance structure to implement regular, periodic updates of management plans in relation to agreed-upon performance indicators. Such a strategy should integrate habitat conservation planning with other state and regional plans and objectives, such as for transportation infrastructure, urban development, and mitigation of climate change.  相似文献   

GIS‐based Calibration of MassMov2D     

Monia Elisa Molinari  Massimiliano Cannata  Santiago Begueria  Christian Ambrosi 《Transactions in GIS》2012,16(2):215-231

MassMov2D is a numerical model for simulating runout and deposition of landslide phenomena over a complex topography that is implemented in the free GIS PCRaster. This research aims at improving the mechanism of MassMov2D calibration and verifying its capability of representing complex landslides. In this article the authors present the enhancement of the MassMov2D code due to the introduction of the Nash‐Sutcliffe coefficient for model efficiency calculation; this enables the replacement of the inefficient ‘trial and error’ approach used for sensitivity analysis and calibration with a semi‐automatic procedure. During this research the improved code was tested in a case study located on the Canaria Valley (Switzerland) where a complex landslide occurred. An optimal set of parameters were calculated for evaluating the effects of a possible further slope failure. The availability of a unique dataset of high resolution digital elevation models just before and after the collapse allowed precise evaluation of the sensitivity and calibration of the model with the new procedure. The results demonstrate that this model is capable of reproducing the observed deposits even though some model limitations were identified in steep slope areas. Finally the study presents the expected scenario due to a future landslide.  相似文献