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Maria Ragosta Rosa Caggiano Mariagrazia D'Emilio Serena Sabia Serena Trippetta Maria Macchiato 《Atmospheric Research》2006,81(4):304-319
Atmospheric particulate concentrations and heavy metal content are measured from March to July 2001 at an industrial site located in a rural zone of the southern Italy. PM10 samples are collected by a low-volume sampler and each sample is analysed by AAS techniques for its content of Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn. We measure also temperature, atmospheric pressure and relative humidity, and we collect anemometric data. The study purpose is the investigation of pollutant levels in an industrial area located in a rather unpolluted region and the characterization of the correlation structure among particulate concentrations, heavy metal content and local meteorological parameters. Data analysis is carried out by means of univariate and multivariate statistical methods. In the investigated period, the average value of PM10 daily concentrations (24 μg Nm− 3) does not exceed the national standard of 40 μg Nm− 3 and only nine values are higher than the European daily limit value of 50 μg Nm− 3. Particularly, the occurrence of two anomalous values (183 μg Nm− 3 in 3 March and 94 μg Nm− 3 in 22 June) seems to be related to no-local events as confirmed both by in situ data measured in the AQM network of Potenza city (about 10 km far from the study area) and by remote measurements performed in the same days. Regarding the heavy metal levels, we observe high levels of Cr (34 ng Nm− 3), Ni (85 ng Nm− 3) and Zn (214 ng Nm− 3) in agreement with the local industrial source pattern. The multivariate analysis, carried out using meteorological parameters as exogenous variables, allow to evaluate the role of the different variables as driving factors of the correlation structure among the metals. 相似文献
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M. Liberti T. Simoniello M.T. Carone R. Coppola M. D'Emilio M. Macchiato 《Geomorphology》2009,106(3-4):333-343
Soil erosion is the most influential component of land degradation for its strong impacts on both natural and agricultural environments. In order to support effective intervention and recovery policies for eroded areas, monitoring techniques should take into account the space–time variability of the processes involved, and make use of assessed mapping methodologies as baseline criteria for studying the dynamics of landform development. When using multispectral data for mapping eroded areas, low spectral separability is a significant limit in areas with complex features, where soil materials are frequently remixed by surface runoff. Since multispectral satellite images are a valuable data source for multi-temporal analyses of erosion processes at the medium scale, we assessed how accurately a badland area can be identified from LANDSAT TM and ETM data. A protocol for an optimal mapping was built up by testing the performance of different supervised algorithms and input layers (spectral and morphological). Tests were carried out in a well-known badland area of Basilicata, Italy, with an extension of 8000 ha. Results obtained from the use of spectral bands (with and without thermal channel) and principal components returned an overall accuracy ranging from 53% (for classification on first three components) to 72% (for classification on all bands from TM), with low values for the kappa coefficient (0.30–0.50), showing that the spectral information alone are insufficient to accurately identify badland areas. In order to improve mapping, we found that the integration of slopes and aspects derived from a Digital Elevation Model (DEM) can overcome problems inherent to the low separability of spectral signatures. The use of morphological data was tested for different classification algorithms and integration approaches. In discriminating badlands, the better performing algorithm was MLC (Maximum Likelihood Classifier) and the best results were obtained by integrating all seven bands (including TIR) with slope and aspect maps as input within the classifier (A > 0.85 and K 0.75 for both the sensors). We selected such parameters because they play an important role in characterising badlands of study area from a morphological perspective but the proposed approach is also conceptually simple and can be easily exported to other areas. The obtained results support the hypothesis that the combined use of remote sensing imagery and auxiliary morphological data significantly improves the mapping of badlands over large areas with heterogeneous features, thus providing a useful methodology for long-term studies on soil erosion processes. 相似文献
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Di Franco A Graziano M Franzitta G Felline S Chemello R Milazzo M 《Marine pollution bulletin》2011,62(5):926-933
Many human activities add new structures to the marine landscape. Despite the fact that human structures cause some inevitable impacts, surprisingly little information exists on the effects of marina on natural marine assemblages. The aim of this paper is to assess habitat-specific response of benthic sessile organisms of rocky shores in relation to the presence of a small marina. Sampling was carried out at three coastal habitats (midshore, lowshore and subtidal) by means of visual censuses adopting an after-control-impact (ACI) experimental design. It appears that the marina affects the structure and composition of benthic communities of both the midshore and the lowshore. Little effect was evident on shallow subtidal assemblage structure. The results of the present study clearly show habitat-specific responses of coastal benthic assemblages to the presence of infrastructure. 相似文献
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Celia Ojeda-Martínez Francisca Giménez Casalduero Just T. Bayle-Sempere Carmen Barbera Cebrián Carlos Valle Jose Luis Sanchez-Lizaso Aitor Forcada Pablo Sanchez-Jerez Pablo Martín-Sosa Jesús M. Falcón Fuensanta Salas Mariagrazia Graziano Renato Chemello Ben Stobart Pedro Cartagena Angel Pérez-Ruzafa Fréderic Vandeperre Elisabeth Rochel Serge Planes Alberto Brito 《Ocean & Coastal Management》2009,52(2):89-101
A general conceptual framework for the management of marine protected areas (MPAs) was developed. The driver-pressure-state-impacts-response (DPSIR) framework was used to determine the elements affecting MPAs. The developed evaluation framework helped to select an appropriate suite of indicators to support an ecosystem approach, an assessment of the MPAs functioning and policy decisions. Gaps derived from the management and policy responses in the MPAs were also outlined. It was concluded that the DPSIR framework can help to simplify the complexity of MPA management. This document is a tool for policy makers, scientists and general public on the relevance of indicators to monitor changes and MPAs management. 相似文献
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The modeling of tethering elements of seabed anchored floating structures is addressed, with particular reference to the so‐called Archimedes Bridge (submerged floating tunnel, SFT) solution for deep water crossing; attention is devoted to the design solution encompassing slender bars as anchor elements. Two numerical tools are proposed: firstly, a geometrically nonlinear finite element (NWB model), developed in previous work, has been refined in order to capture the effect of higher flexural modes of anchor bars. Secondly, a 3D beam element, based on the classical corotational formulation (CR model), has been developed and coded. Both elements are implemented in a numerical procedure for the dynamic time domain step‐by‐step analysis of nonlinear discretized systems; seismic loading is introduced by generating artificial time histories of spatially variable seismic motion. An example of application of the NWB element is shown regarding the behavior of the dynamic model of a complete SFT. The model was subjected to extreme multiple‐support seismic loading. The seismic behavior is here illustrated and commented, especially in light of the effect of higher local vibration modes of the anchor bars. Finally, a comparison between the performances of the two modeling approaches is presented. Both harmonic and seismic excitations are considered in the test; the results justify the use of the simpler NWB approach, especially in the SFT design phase. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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The influence of structural organization of epilithic and endolithic lichens on limestone weathering 
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下载免费PDF全文 Mariagrazia Morando Katrin Wilhelm Enrica Matteucci Luca Martire Rosanna Piervittori Heather A. Viles Sergio Enrico Favero‐Longo 《地球表面变化过程与地形》2017,42(11):1666-1679
Hyphal penetration, mineral dissolution and neoformation at the lichen–rock interface have been widely characterized by microscopic and spectroscopic studies, and considered as proxies of lichen deterioration of stone substrates. However, these phenomena have not been clearly related to experimental data on physical properties related to stone durability, and the physical consequences of lichen removal from stone surfaces have also been overlooked. In this study, we combine microscopic and spectroscopic characterization of the structural organization of epi‐ and endolithic lichens (Caloplaca marina (Wedd.) Du Rietz, Caloplaca ochracea (Schaer.) Flagey, Bagliettoa baldensis (A.Massal.) Vězda, Porina linearis (Leight.) Zahlbr., Verrucaria nigrescens Pers.) at the interface with limestones of interest for Cultural Heritage (Portland Limestone, Botticino Limestone), with analysis of rock properties (water absorption, surface hardness) relevant for durability, before and after the removal or scraping of lichen thalli. Observations using reflected‐light and electron microscopy, and Raman analyses, showed lichen–limestone stratified interfaces, differing in the presence/absence and depth of lichen anatomical layers (lithocortex, photobiont layer, pervasive and sparse hyphal penetration component) depending on species and lithology. Specific structural organizations of lichen–rock interface were found to be associated with differential patterns of water absorption increase, evaluated by Karsten tube, in comparison with surfaces with microbial biofilms only, even more pronounced after the removal or scraping of the upper structural layers. Equotip measurements on surfaces bearing intact thalli showed lower hardness in comparison with control surfaces. By contrast, after the removal or scraping procedures, Equotip values were similar to or higher than those of controls, suggesting that the increasing open porosity may be related to a biogenic hardening process. Such counterposed patterns of porosity increase and hardening need to be considered when models relating lichen occurrence on limestones and biogeomorphological surface evolution are proposed, and to evaluate the consequences of lichen removal from stone‐built cultural heritage. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
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