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21.
Lisa M. Campbell Noëlle Boucquey Joshua Stoll Henry Coppola Martin D. Smith 《社会与自然资源》2014,27(1):88-106
Community-supported fisheries (CSF) projects show signs of rapid growth. Modeled on community-supported agriculture (CSA) projects, CSFs share objectives of reducing social and physical distance between consumers and producers and re-embedding food systems in social and environmental contexts. This article offers a comparison of CSF and CSA, situated in the differences between seafood and agricultural products, and fishing and farming. We draw on economic and resource theory, past research on CSA, and a member survey from a case study CSF. Survey results show CSF members are interested in accessing high-quality, fresh, local seafood, and in supporting fishing communities, and they believe that participating in a CSF achieves both. They are less certain that a CSF can address environmental concerns, and few identify environmental motives as their primary reason for participating. The latter contrasts with CSA research results, and we contextualize these findings in our broader comparison. 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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We have used the extensive set of photometric data in the VBLUW system (Pel, 1976) to perform a thorough statistical analysis of the physical properties of Cepheid variables, which can be inferred directly from these data. We have dealt with the problem of determining colour excesses and mean colours and temperatures; theoretical masses, radii and luminosities have been recalculated. 相似文献
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Giorgio Socal Francesco Acri Mauro Bastianini Fabrizio Bernardi Aubry Franco Bianchi Daniele Cassin Joan Coppola Amelia De Lazzari Vinko Bandelj Gianpiero Cossarini Cosimo Solidoro 《Marine Ecology》2008,29(4):449-468
This paper reports on the main biogeochemical properties of the Northern Adriatic Sea in the period May 2003–November 2006 within the framework of the European program INTERREG III Italy‐Slovenia. Spatial and temporal distributions of water density, dissolved oxygen, nutrients (nitrogen, phosphorous and silicon) and chlorophyll a are presented. Multivariate methods such as fuzzy k‐means, self‐organising maps and cluster analysis were used to identify the different water masses and to characterise the temporal and spatial variability of the main biogeochemical features present in the area. The results confirm that the Po River outflows and the meteorological forcing factors are the main components triggering the alternation of stratification and mixing of the water column and that strongly affect the trophic state of the basin. In general, oligotrophic conditions dominate, and were more pronounced offshore, but mesotrophy occurred episodically in May 2004 and July 2005, when phytoplankton blooms were observed concomitant with vertical stability of the water column. A marked interannual variability was also observed, supporting the importance of maintaining long‐term observations of the basin. 相似文献
25.
Sang-Han Lee Pavel P. Povinec Janine Gastaud Beniamino Oregioni Laurent Coppola Catherine Jeandel 《Journal of Oceanography》2009,65(3):397-406
Anthropogenic 90Sr, 239,240Pu and 241Am were used as tracers of water mass circulation in the Crozet Basin of the South Indian Ocean, represented by three main
water fronts—Agulhas (AF), Subtropical (STF) and Subantarctic (SAF). Higher 90Sr concentrations observed north of 43°S were due to the influence of AF and STF, which are associated with the south branch
of the Subtropical gyre, which acts as a reservoir of radionuclides transported from the North to the South Indian Ocean.
On the other hand, the region south of 43°S has been influenced by SAF, bringing to the Crozet Basin Antarctic waters with
lower radionuclide concentrations. The 238Pu/239,240Pu activity ratios observed in water and zooplankton samples indicated that, even 35 years after the injection of 238Pu to the Indian Ocean from the burn-up of the SNAP-9A satellite, the increased levels of 238Pu in surface water and zooplankton are still well visible. The radionuclide concentrations in seawater and their availability
to zooplankton are responsible for the observed 210Po, 239,240Pu and 241Am levels in zooplankton. 相似文献
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Modelling of field-scale transport of chemicals is of deep interest to public as well as private sectors, and it represents an area of active theoretical research in many environmentally-based disciplines. However, the experimental data needed to validate field-scale transport models are very limited due to the numerous logistic difficulties that one faces out. 相似文献
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Regional climate model projections over the Mediterranean region are analysed for the presence of intense, warm-core lows that share some of the characteristics of tropical cyclones. The results indicate that the number of such systems decreases in a warmer world, particularly in winter. Comparison of the simulated numbers to changes in relevant climate diagnostics suggests that numbers decrease due to an increasingly hostile environment for storm formation, combined with a general poleward shift in the incidence of wintertime lows over western Europe. 相似文献
30.
G. T. Diro F. Giorgi R. Fuentes-Franco K. J. E. Walsh G. Giuliani E. Coppola 《Climatic change》2014,125(1):79-94
The characteristics of tropical cyclones (TCs) over the Central America Coordinated Regional Downscaling Experiment (CORDEX) domain are examined for present and future climate conditions using the regional climate model RegCM4. RegCM4 is first tested in a 22 year (1982–2003) simulation with boundary forcing from the ERA-Interim reanalysis, showing a generally good performance in reproducing the observed TC climatology and over the Atlantic in reproducing the interannual variations of TC counts. Four scenario simulations (1970-2100) are generated using two model configurations and two driving global models (MPI and HadGEM). The simulations employing the Grell convection scheme produce too few TCs, while those using the Emanuel convection scheme reproduce the observed climatology, especially when driven by the MPI global model. The simulation of TCs is thus sensitive to both the model convection scheme and the forcing GCM. Comparison of future and present day TC statistics indicates that the frequency of future TCs decreases over the tropical Atlantic and the East Pacific coastal areas while it increases over the western areas of the East Pacific and the northern areas of the Atlantic. We also find an increase in the frequency of intense TCs and long lasting TCs, along with a northward shift of TC tracks over the Atlantic. Conclusions on the changes in TC activity are not found to be sensitive to the inclusion of SST thresholds in the detection procedure. These findings 相似文献