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1.
Frey, Ashley E., Francisco Olivera, Jennifer L. Irish, Lauren M. Dunkin, James M. Kaihatu, Celso M. Ferreira, and Billy L. Edge, 2010. Potential Impact of Climate Change on Hurricane Flooding Inundation, Population Affected and Property Damages in Corpus Christi. Journal of the American Water Resources Association (JAWRA) 1–11. DOI: 10.1111/j.1752-1688.2010.00475.x Abstract: The effect of climate change on storm-surge flooding and the implications for population and structural damages on the city of Corpus Christi, Texas, was investigated. The study considered the influence of sea level rise and hurricane intensification, both influenced by climate change. Combinations of future carbon dioxide equivalent emission rates and carbon dioxide doubling sensitivities, based on findings of the Intergovernmental Panel on Climate Change, were considered to define future climate scenarios. A suite of physically based numerical models for hurricane winds and the resulting waves, surge, and morphological change at the coast were used to determine flooded areas, population affected, and property damages for Hurricanes Bret, Beulah, and a version of Carla shifted south from its original track, under present and predicted future climate conditions. A comparison of the economic damages for current climate conditions and for the 2080s climate scenario shows that, for Carla (shifted), there will be an increase in the range of $270-1,100 million; for Beulah, of $100-390 million; and, for Bret, of $30-280 million. A similar analysis was also conducted for 2030s predicted climate scenarios. Overall, the comparison of the results for the different climate conditions indicates what the destructive consequences of climate change could be, even within the somewhat short time frame of 80 years considered here.  相似文献   
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There is increasing interest in the United States in producing biosolids from municipal wastewater treatment that meet the criteria for Class A designation established by the U.S. Environmental Protection Agency. Class A biosolids are intended to be free of pathogens and also must meet requirements for reduction of the vector-attraction potential associated with untreated sludge. High-temperature processes are considered to produce Class A biosolids if the combination of operating temperature and treatment time exceeds minimum criteria, but this option is not applicable to mixed, continuous-flow reactors. Such reactors, or any combination of reactors that does not meet the holding time requirement at a specific temperature, must be demonstrated to inactivate pathogens to levels consistent with the Class A criteria. This study was designed to evaluate pathogen inactivation by thermophilic anaerobic digestion in a mixed, continuous-flow reactor followed by batch or plug-flow treatment. In this first of a two-part series, we describe the performance of a continuous-flow laboratory reactor with respect to physical and chemical operating parameters; microbial inactivation in the combined continuous-flow and batch treatment system is described in the second part. Sludges from three different sources were treated at 53 degrees C, while sludge from one of the sources was also treated at 55 and 51 degrees C. Relatively short hydraulic retention times (four to six days) were used to represent a conservative operating condition with respect to pathogen inactivation. Treatment of a fermented primary sludge led to an average volatile-solids (VS) destruction efficiency of 45%, while VS destruction for the other two sources was near or below 38%, the Class A criterion for vector attraction reduction. Consistent with other studies on thermophilic anaerobic digestion of sludges at short residence times, effluent concentrations of volatile fatty acids (VFAs) were relatively high. Also consistent with other studies, the most abundant VFA in the effluent was propionate. Gas production ranged from 0.3 to 0.5 m3/kg VS fed and from 0.8 to 1.3 m3/kg VS destroyed.  相似文献   
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Abstract: A primary water quality problem caused by non-point source pollution (NPSP) is eutrophication, from excess nutrients in receiving water bodies. The control of nutrients arising from NPSP is difficult because the source areas can be hard to identify and typical treatment methods are infeasible due to the distributed nature of the pollutants. It may be possible to reduce nutrient related water quality problems through the restoration of highly disturbed watersheds with best management practices (BMPs). While restoration attempts may provide significant returns, they can be costly to implement and often are met with resistance in agricultural communities. Extending model results beyond the range of calibration to model future conditions such as for restoration scenarios requires the use of physically-based models that include the important processes that generate streamflow and material transport, uptake, loss, transformation, and recycling of nutrients and other material. The research and development objectives of the US. Army Engineer Research and Development Center (ERDC) in Vicksburg, Mississippi, are to develop a watershed assessment and management model to simulate transport, uptake, loss, transformation, and recycling of nutrients such as nitrogen and phosphorus and associated material such as sediment and organic matter. In this study we will discuss current efforts at the ERDC's Environmental Laboratory to develop a state-of-the-art watershed water quality model.  相似文献   
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ABSTRACT: The major objective is to report the way the Delphi methodology was employed in an environmental study aimed at identifying and ranking goals and social impacts of Cooper Dam and Reservoir Project located in the East Texas area. The Delphi procedures were modified to accommodate the nature of social field under study. Data were collected through personal interviews from twenty-seven respondents representing the government agency responsible for planning the Project and three communities geographically contiguous to the project. The respondents were provided an initial list of the Project's goals and social impacts and were asked to rank them in terms of degree of importance and to add to the list other goals and impacts that they would consider necessary. Respondents were interviewed in two successive rounds. Data show that on the whole the Delphi procedures were helpful in action analysis of the Project by identifying and ranking its goals and social impacts in terms of selected criteria.  相似文献   
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 利用香港2 个监测站的VOCs 组分监测数据对香港PATH 模型进行了验证分析.结果明,PATH 模型在模拟VOCs 组分浓度上存在较大的误差.实际观测的VOCs 组分AOD、OLE、TOL 和XYL 浓度是模型模拟的2~3 倍;而模型模拟的PAR 和ETH 浓度是实际观测的 2~4倍.这些误差可能是由于当前使用的VOCs 排放清单低估了实际的VOCs 排放量,以及在估算来自不同排放源的排放量及组分分布上有较大的不确定性.使用高质量的VOCs 组分监测数据验证PATH 模型有助于指导改进VOCs 排放清单和理解复杂的光化学烟雾污染问题,从而改进和提高PATH 模型.  相似文献   
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Cost–benefit analysis has been criticised on the grounds that it cannot compute the value of environmental goods whose value constitutively defies monetary valuation. Two forms of incommensurability make monetary valuation problematic: constitutive incommensurability and quantitative incommensurability. These pose a threat only to shadow pricing, and not the formation of prices in an actual market. Where property rights to environmental goods are appropriately assigned, the prices that form reflect the actual uses persons put them to, given their value commitments. In a real market, the formation of prices does not depend upon the assignment of cardinal values via monetary valuation; rather, the formation of prices is a side effect of the way in which environmental goods are used. A property right gives one the right to reject terms of exchange one deems inappropriate. Where sale of an environmental good is deemed inappropriate, it is kept out of the cash nexus. Incommensurability therefore precludes cost–benefit analysis, but not markets in environmental goods where property rights are appropriately allocated.  相似文献   
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OBJECTIVE: To explore the epidemiology of pedestrian deaths in Dallas County, Texas, and to compare factors associated with pedestrian deaths on expressways versus those that occurred on other roadways. METHODS: We studied all pedestrian deaths among persons 15 years of age or older in Dallas County, Texas, from 1997 to 2004 by linking data from Medical Examiner's office, the Fatality Analysis Reporting System, and local police records. Univariate and multivariate analysis compared various factors associated with death on an expressway. RESULTS: Among 437 pedestrian deaths who were 15 years of age or older, 197 (45%) occurred on expressways; the proportion that occurred on expressways was highest among 15- to 29-year-olds (65%) and was lower with advancing age group (p < 0.01, chi square for trend). At least 36% of these expressway-related pedestrian deaths were known to have been "unintended pedestrians," who had exited a vehicle after being on the roadway, compared with 11% of pedestrian deaths on surface streets (OR 4.6, 95% CI, 2.7-8.1), and this was also highest among younger age groups. Pedestrian deaths on an expressway, compared with deaths on surface streets, remained strongly associated with having been an "unintended pedestrian" (OR 6.2, 95% CI, 3.1-14.0), after controlling for several other variables, including age, sex, race, nighttime of crash, and alcohol involvement. CONCLUSIONS: Expressways are the predominant site of fatal pedestrian crashes among young adults in this urban area. Since many of these deaths were "unintended pedestrians," procedures for management of occupants of disabled vehicles on expressways could have a large impact on pedestrian deaths in young adults.  相似文献   
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An accounts is given of current work in the field of radioactivity measurements in the marine and terrestrial environments of the United Kingdom. Reference is made to the increasing need for quality assurance and to the role of measurements standards and traceability.  相似文献   
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Water quality of least-impaired lakes in eastern and southern Arkansas   总被引:1,自引:0,他引:1  
A three-phased study identified one least-impaired (reference) lake for each of four Arkansas lake classifications: three classifications in the Mississippi Alluvial Plain (MAP) ecoregion and a fourth classification in the South Central Plains (SCP) ecoregion. Water quality at three of the least-impaired lakes generally was comparable and also was comparable to water quality from Kansas and Missouri reference lakes and Texas least-impaired lakes. Water quality of one least-impaired lake in the MAP ecoregion was not as good as water quality in other least-impaired lakes in Arkansas or in the three other states: a probable consequence of all lakes in that classification having a designated use as a source of irrigation water. Chemical and physical conditions for all four lake classifications were at times naturally harsh as limnological characteristics changed temporally. As a consequence of allochthonous organic material, oxbow lakes isolated within watersheds comprised of swamps were susceptible to low dissolved oxygen concentrations to the extent that conditions would be limiting to some aquatic biota. Also, pH in lakes in the SCP ecoregion was <6.0, a level exceeding current Arkansas water-quality standards but typical of black water systems. Water quality of the deepest lakes exceeded that of shallow lakes. N/P ratios and trophic state indices may be less effective for assessing water quality for shallow lakes (<2 m) than for deep lakes because there is an increased exposure of sediment (and associated phosphorus) to disturbance and light in the former.  相似文献   
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