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421.
422.
MM5-SMOKE-CMAQ as a modeling tool for 8-h ozone regulatory enforcement: application to the state of Arizona 总被引:1,自引:0,他引:1
Sang-Mi Lee H. J. S. Fernando S. Grossman-Clarke 《Environmental Modeling and Assessment》2007,12(1):63-74
The Penn State/NCAR Mesoscale Meteorological Model 5 (MM5), Sparse Matrix Operator Kernal Emissions (SMOKE), and Community
Multiscale Air Quality (CMAQ) modeling systems were employed to simulate ozone concentration distribution within the State
of Arizona, in particular, Phoenix air basin, as supporting information to designate nonattainment areas of the U.S. Environmental
Protection Agency's new 8-h ozone standard. In general, based on statistical comparisons between predictions and available
(sparsely distributed) observations, the modeling system performed reasonably well for the Phoenix basin, thus proving it
to be a useful tool for both regulatory as well as research applications. Detailed inspection, however, revealed a serious
problem with respect to the details of the ozone distribution in that for some days the transition from downslope flow to
upslope flow in the Phoenix basin was delayed in the model, causing the ozone distribution to show an unrealistic high-ozone
bias toward the west valley. Implementation of a modified subgrid parameterization improved the time of transition, and hence
the prediction of ozone and its precursor distributions. This study points to possible inadequacies of commonly used subgrid
parameterizations in dealing with rapidly changing flow conditions such as morning (and evening) transitions. 相似文献
423.
424.
425.
Jeffrey O. Hanson Ana Veríssimo Guillermo Velo-Antón Adam Marques Miguel Camacho-Sanchez Íñigo Martínez-Solano Helena Gonçalves Fernando Sequeira Hugh P. Possingham Silvia B. Carvalho 《Conservation biology》2021,35(2):634-642
Protected-area systems should conserve intraspecific genetic diversity. Because genetic data require resources to obtain, several approaches have been proposed for generating plans for protected-area systems (prioritizations) when genetic data are not available. Yet such surrogate-based approaches remain poorly tested. We evaluated the effectiveness of potential surrogate-based approaches based on microsatellite genetic data collected across the Iberian Peninsula for 7 amphibian and 3 reptilian species. Long-term environmental suitability did not effectively represent sites containing high genetic diversity (allelic richness). Prioritizations based on long-term environmental suitability had similar performance to random prioritizations. Geographic distances and resistance distances based on contemporary environmental suitability were not always effective surrogates for identification of combinations of sites that contain individuals with different genetic compositions. Our results demonstrate that population genetic data based on commonly used neutral markers can inform prioritizations, and we could not find an adequate substitute. Conservation planners need to weigh the potential benefits of genetic data against their acquisition costs. 相似文献
426.
Burger JR Chesh AS Muñoz P Fredes F Ebensperger LA Hayes LD 《Behavioral ecology and sociobiology》2012,66(1):57-66
Social animals are susceptible to high infection levels by contact-transmitted parasites due to increased conspecific interaction.
Exotic parasites are known to have adverse consequences on native hosts. We examined the relationship between social group
size and exotic ectoparasite loads, and adult infection levels with per capita fitness and offspring survival in the plural
breeding rodent Octodon degus in central Chile. Degus at our site were almost entirely infected by two exotic ectoparasites: the fleas Leptopsylla segnis and Xenopsylla cheopis. Neither group size nor number of females per group predicted the abundance of either exotic flea species. The per capita
number of pups (per capita fitness) that emerged from burrow systems used by known social groups was negatively correlated
with abundance of L. segnis but not X. cheopis. On adults, X. cheopis abundance was three times greater than L. segnis but was not significantly correlated with per capita fitness. In females, L. segnis abundance was negatively correlated with peak body mass during pregnancy. Adult ectoparasite load was not correlated with
offspring survival. Based on these results, we hypothesize that high infection levels of L. segnis result in decreased reproductive fitness of adult female degus but are not a cost of sociality because parasite loads are
not predicted by social group size. Further work is needed to experimentally test this hypothesis and to determine if L. segnis serves as a vector for a deleterious pathogen. Lastly, the lack of native ectoparasites may explain why a previous study
at our site determined that behavioral adaptations needed to cope with high ectoparasite burdens (e.g., grooming) are not
extensive in degus; they simply have not had the coevolutionary time needed for selection of these behaviors. 相似文献
427.
Although PVC-containing wastes are an important potential source of energy they are frequently disposed in landfill. In thermal treatment processes such as pyrolysis and gasification, the presence of poly(vinyl chloride) (PVC), a compound with 56.7% of chlorine, may cause problems concerned with environmental protection, as consequence of the formation of hydrochloric acid, chlorine gas and dioxins, as well as corrosion phenomena of the reactor/equipment materials. Thus, a possible solution may involve a previous removal of the chlorine from PVC containing waste through a pyrolysis process at low temperatures before the material being submitted to a subsequent thermal treatment, for energetic valorization. In this work, a kinetic model for the thermal decomposition of PVC has been developed, in view of its de-chlorination. DTA/TGA testing at different temperatures indicated a first order reaction and an activation energy of 133,800J/mol. An almost completed de-chlorination reaction was obtained at 340°C under an inert atmosphere. The resulted material is a C(n)H(n) type polymer with potential to be used in an energy recovery process. Validation test performed at laboratory scale indicate that the temperature of 340°C enables the removal of ~99.9% of the chlorine present in PVC. The chloride can be fixed in the form of an aqueous solution of HCl or calcium chloride, driving to an alternative full process with environmental benefits and reduction of the costs associated to the PCV - containing materials/wastes management. 相似文献
428.
Steady-state, dynamic, and spatial models were constructed for the benthic system of La Rinconada Marine Reserve off northern Chile (SE Pacific coast). We examined data on biomass, P/B ratios, catches, food spectrum, consumption, and the dynamics of commercial and non-commercial populations using three theoretical frameworks: Ecopath, Ecosim, and Ecospace. The biomass of the scallop Argopecten purpuratus and the clam Tagelus dombeii were the most relevant compartments of the studied ecosystem. Among the carnivores, the functional crab group Cancer spp. was the most relevant. The Rhodophyta was the dominant macroalga compartment of the system. The results obtained using mixed trophic impacts (MTI) showed that the predatory snail Thais chocolata propagated higher magnitudes of direct and indirect effects on the other species or functional groups. The sea star Luidia magallanica and Rhodophyta had the least effects on the remaining compartments. According to the Ecosim estimates (increasing mortality by fishing), the scallop A. purpuratus had the highest impact on the other compartments. The Ecospace model showed similar qualitative and quantitative effects for changes in biomass under three different exploitation scenarios (by subsystems and globally). Nevertheless, the greatest changes were provoked by using the top-down control and the vulnerabilities estimated by Ecosim. System recovery times were highest with increased mortality of the asteroid L. magallanica and the carnivorous snail T. chocolata, suggesting that the sea star could be considered to be a top predator with a top-down control. The FMSY estimated for the scallop A. purpuratus was close to the Fi originally entered in Ecopath, limiting the design and execution of an exploitation plan within ecologically sustainable boundaries. The situation was different (FMSY ? Fi) for the other commercial species, making possible multi-species exploitation programs. The Ecospace trophic-spatially explicit model shows a similar pattern of direct and indirect effects generated when exerting exploitation separately by subsystems. Therefore, habitat rotation of fisheries is not justified. 相似文献
429.
A ‘coastal-hazard GIS’ for Sri Lanka 总被引:1,自引:1,他引:0
Jean-François Desprats Manuel Garcin Nishanta Attanayake Rodrigo Pedreros Cheer Siriwardana Mélanie Fontaine Starin Fernando Udaya De Silva 《Journal of Coastal Conservation》2010,14(1):21-31
Following the 2004 tsunami disaster in Sri Lanka, it was apparent that mapping the coast’s vulnerability was essential for
future protection of the local populations. We therefore developed a prototype ‘Coastal-hazard GIS’ for Sri Lanka so as to
provide an effective tool for decision makers to limit the impact of natural coastal hazards such as sea level rise, tsunamis,
storm surges and coastal erosion, and thus protect the exposed assets (population, property, settlements, communications networks,
etc.). The prototype was developed on a pilot site in Galle through building up homogeneous data on the land/sea interface
from studies conducted on the exposure of the coastal populations, the aim being to enable an evaluation of the hazards combined
with the vulnerability and thus an analysis of the risks. Coastal risk scenarios are developed so as to estimate the impacts
and consequences of an event (tsunami, storm, etc.) on the assets, the principle behind this being that if, in general, the
coastal hazard cannot be decreased, then a better knowledge of it through simulation should make it possible to limit the
vulnerability and thus the risk. The Coastal-hazard GIS will also provide a planning tool in terms of locating new settlements,
expanding urban areas, siting coastal protection works, etc. 相似文献
430.
The sequential extraction procedures described by Tessier et al., McGrath and Cegarra, and Gimeno-García et al. were compared
to investigate trace element (As, Cr, Cu, Pb, and Zn) partitioning patterns and extraction efficiency in three contaminated
soils from Mediterranean regions of Spain. Soils were selected from Onda (Castellón) (S1), Aznalcóllar (Sevilla) (S2), and
Silla (Valencia) (S3). S1 was a soil contaminated with Pb and Zn after dumping of wastes from the manufacture of ceramic tiles,
S2 was polluted accidentally with a highly acid and As-concentrated sludge from mining activities, and S3 was a soil with
a high Cr content from tannery sludge disposal. Trace element distribution in the soils—soluble, exchangeable, organically
bound, precipitated with carbonates, bound to iron and manganese oxides, and precipitated with sulfides fractions—varied significantly
according to the extraction procedure used. In addition, different extraction efficiencies were found for the three sequential
extraction procedures compared. Finally, the trace elements studied showed different and specific distribution patterns between
the various soil fractions examined. 相似文献