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251.
The impact of dominant trends in public administration, such as decentralisation and privatisation on complex collective challenges is insufficiently understood. This is relevant in settings where climate change impacts become manifest at local level, and where financing power resides at national level but decisions are made more locally in a fragmented institutional setting. This study assists in overcoming this gap by analysing how the institutional context (i.e. a decentralised, privatised, fragmented setting) influences the capacity to address climate change challenges in a vulnerable area (the South Devon coast in the UK). There has been little action to address expected climate change impacts in this vulnerable stretch of coast. A lack of clarity around responsibility for addressing climate impacts and a lack of a deliberative structure between various actors involved, within a context of austerity, hamper climate change adaptation. The findings question whether decentralised decision making is sufficient for addressing climate adaptation challenges. 相似文献
252.
A New Open‐Access HUC‐8 Based Downscaled CMIP‐5 Climate Model Forecast Dataset for the Conterminous United States 下载免费PDF全文
Dustin H. Woodbury Daniel P. Ames Jiří Kadlec Stephen Duncan Greg Gault 《Journal of the American Water Resources Association》2016,52(4):906-915
Watershed‐scale hydrologic simulation models generally require climate data inputs including precipitation and temperature. These climate inputs can be derived from downscaled global climate simulations which have the potential to drive runoff forecasts at the scale of local watersheds. While a simulation designed to drive a local watershed model would ideally be constructed at an appropriate scale, global climate simulations are, by definition, arbitrarily determined large rectangular spatial grids. This paper addresses the technical challenge of making climate simulation model results readily available in the form of downscaled datasets that can be used for watershed scale models. Specifically, we present the development and deployment of a new Coupled Model Intercomparison Project phase 5 (CMIP5) based database which has been prepared through a scaling and weighted averaging process for use at the level of U.S. Geological Survey (USGS) Hydrologic Unit Code (HUC)‐8 watersheds. The resulting dataset includes 2,106 virtual observation sites (watershed centroids) each with 698 associated time series datasets representing average monthly temperature and precipitation between 1950 and 2099 based on 234 unique climate model simulations. The new dataset is deployed on a HydroServer and distributed using WaterOneFlow web services in the WaterML format. These methods can be adapted for downscaled General Circulation Model (GCM) results for specific drainage areas smaller than HUC‐8. Two example use cases for the dataset also are presented. 相似文献
253.
In this study we investigated the effect of uranium on the growth of the bacterium Thermus scotoductus strain SA-01 as well as the whole cell U(VI) reduction capabilities of the organism. Also, site-directed mutagenesis confirmed the identity of a protein capable of a possible alternative mechanism of U(VI) reduction. SA-01 can grow aerobically in up to 1.25 mM uranium and has the capability to reduce low levels of U(VI) in under 20 h. TEM analysis performed on cells exposed to uranium showed extracellular and membrane-bound accumulation of uranium. The reductase-like protein was surprisingly identified as a peptide ABC transporter, peptide-binding protein. This study showcases the concept of protein promiscuity, where this protein with a distinct function in situ can also have the unintended function of a reactant for the reduction of U(VI). 相似文献
254.
T. Duncan Fairlie James Szykman Alice Gilliland R. Bradley Pierce Chieko Kittaka Stephanie Weber Jill Engel-Cox Raymond R. Rogers Joe Tikvart Rich Scheffe Fred Dimmick 《Atmospheric environment (Oxford, England : 1994)》2009,43(20):3275-3288
We use ensemble-mean Lagrangian sampling of a 3-D Eulerian air quality model, CMAQ, together with ground-based ambient monitors data from several air monitoring networks and satellite (MODIS) observations to provide source apportionment and regional transport vs. local contributions to sulfate aerosol and PM2.5 concentrations at Baltimore, MD, for summer 2004. The Lagrangian method provides estimates of the chemical and physical evolution of air arriving in the daytime boundary layer at Baltimore. Study results indicate a dominant role for regional transport contributions on those days when sulfate air pollution is highest in Baltimore, with a principal transport pathway from the Ohio River Valley (ORV) through southern Pennsylvania and Maryland, consistent with earlier studies. Thus, reductions in sulfur emissions from the ORV under the EPA's Clean Air Interstate Rule may be expected to improve particulate air quality in Baltimore during summer. The Lagrangian sampling of CMAQ offers an inexpensive and complimentary approach to traditional methods of source apportionment based on multivariate observational data analysis, and air quality model emissions separation. This study serves as a prototype for the method applied to Baltimore. EPA is establishing a system to allow air quality planners to readily produce and access equivalent results for locations of their choice. 相似文献
255.
Kent DB Davis JA Joye JL Curtis GP 《Environmental pollution (Barking, Essex : 1987)》2008,153(1):44-52
Adsorption of Ni and Pb on aquifer sediments from Cape Cod, Massachusetts, USA increased with increasing pH and metal-ion concentration. Adsorption could be described quantitatively using a semi-mechanistic surface complexation model (SCM), in which adsorption is described using chemical reactions between metal ions and adsorption sites. Equilibrium reactive transport simulations incorporating the SCMs, formation of metal-ion-EDTA complexes, and either Fe(III)-oxyhydroxide solubility or Zn desorption from sediments identified important factors responsible for trends observed during transport experiments conducted with EDTA complexes of Ni, Zn, and Pb in the Cape Cod aquifer. Dissociation of Pb-EDTA by Fe(III) is more favorable than Ni-EDTA because of differences in Ni- and Pb-adsorption to the sediments. Dissociation of Ni-EDTA becomes more favorable with decreasing Ni-EDTA concentration and decreasing pH. In contrast to Ni, Pb-EDTA can be dissociated by Zn desorbed from the aquifer sediments. Variability in adsorbed Zn concentrations has a large impact on Pb-EDTA dissociation. 相似文献
256.
Lee MH Clingenpeel SC Leiser OP Wymore RA Sorenson KS Watwood ME 《Environmental pollution (Barking, Essex : 1987)》2008,153(1):238-246
A variety of naturally occurring bacteria produce enzymes that cometabolically degrade trichloroethene (TCE), including organisms with aerobic oxygenases. Groundwater contaminated with TCE was collected from the aerobic region of the Test Area North site of the Idaho National Laboratory. Samples were evaluated with enzyme activity probes, and resulted in measurable detection of toluene oxygenase activity (6-79% of the total microbial cells). Wells from both inside and outside contaminated plume showed activity. Toluene oxygenase-specific PCR primers determined that toluene-degrading genes were present in all groundwater samples evaluated. In addition, bacterial isolates were obtained and possessed toluene oxygenase enzymes, demonstrated activity, and were dominated by the phylotype Pseudomonas. This study demonstrated, through the use of enzymatic probes and oxygenase gene identification, that indigenous microorganisms at a contaminated site were cometabolically active. Documentation such as this can be used to substantiate observations of natural attenuation of TCE-contaminated groundwater plumes. 相似文献
257.
Throughout 2004, PM(10) concentrations were measured at 10 min intervals at Hazelrigg, a remote location in NW England. The annual mean concentration was 6.1 microg m(-3) and likely origins were determined using directional and particle size characteristics. The fine temporal resolution of the monitoring also allowed several short periods (< 20 h) of persistently high PM(10) concentration to be identified and then 'typed' by event start time, duration, wind direction and particle size characteristics. A series of night time PM(10) anomalies (concentration < 465 microg m(-3)) of no obvious source were identified, and by elimination assumed to have originated from a ground-based fire of particle-rich fodder. A novel methodology combining Stokes' Law with systematic and rigorous modelling of source strength (using ADMS3.2) was developed to locate a possible burn site. The process was limited by the lack of previous modelling studies related to ground-based fires, and also by the capacity of ADMS3.2 to model sub-hourly time-varying emissions and fluctuations in wind speed and direction in the near field. However, modelling did suggest the source was located <400 m SSE of Hazelrigg, and investigation of this area revealed a burn site where tyres and plastic bags were piled nearby. Few studies have combined directional analysis and modelling to locate a source based on sampled data. This innovative methodology could be used by regulatory bodies to investigate the origins of unidentified PM(10) observed within the particle record. 相似文献
258.
Effect of Hunting in Source-Sink Systems in the Neotropics 总被引:3,自引:0,他引:3
Andres J. Novaro § Kent H. Redford † and Richard E. Bodmer‡ 《Conservation biology》2000,14(3):713-721
Abstract: Previous studies of the sustainability of wildlife hunting in the Neotropics have not considered the potential dispersal of animals into hunted areas. A literature review of studies of subsistence hunting in the Neotropics suggests that hunting is often conducted in areas adjacent to relatively undisturbed habitat that may act as sources of animals for the hunted sites. We compared studies of tapir ( Tapirus terrestris ) hunting at different sites to illustrate the potential bias of sustainability evaluations based on local productivity. The limited information available suggests that dispersal could have a key role in rebuilding animal populations depleted by hunting. Thus, factors that strongly affect dispersal—such as spatial distribution and size of areas with and without hunting, population size in source areas, and social behavior—should be considered when the sustainability of hunting is evaluated in areas with heterogeneous hunting pressure. We suggest the application of two models that use spatial controls (recognizing the potential source-sink nature of some hunted systems and protecting unhunted refugia) to avoid wildlife overexploitation when biological data and enforcement capabilities to regulate harvests are limited. This approach may produce more reliable evaluations of sustainability, provide information on the dynamics of hunting systems, and help local communities and policymakers conserve key areas (including protected areas) that may act as game sources. 相似文献
259.
Fiifi Amoako Johnson Craig W. Hutton Duncan Hornby Attila N. Lázár Anirban Mukhopadhyay 《Sustainability Science》2016,11(3):423-439
The Ganges–Brahmaputra–Meghna delta of Bangladesh is one of the most populous deltas in the world, supporting as many as 140 million people. The delta is threatened by diverse environmental stressors including salinity intrusion, with adverse consequences for livelihood and health. Shrimp farming is recognised as one of the few economic adaptations to the impacts of the rapidly salinizing delta. Although salinity intrusion and shrimp farming are geographically co-located in the delta, there has been no systematic study to examine their geospatial associations with poverty. In this study, we use multiple data sources including Census, Landsat Satellite Imagery and soil salinity survey data to examine the extent of geospatial clustering of poverty within the delta and their associative relationships with salinity intensity and shrimp farming. The analysis was conducted at the union level, which is the lowest local government administrative unit in Bangladesh. The findings show a strong clustering of poverty in the delta, and whilst different intensities of salinization are significantly associated with increasing poverty, neither saline nor freshwater shrimp farming has a significant association with poverty. These findings suggest that whilst shrimp farming may produce economic growth, in its present form it has not been an effective adaptation for the poor and marginalised areas of the delta. The study demonstrates that there are a series of drivers of poverty in the delta, including salinization, water logging, wetland/mudflats, employment, education and access to roads, amongst others that are discernible spatially, indicating that poverty alleviation programmes in the delta require strengthening with area-specific targeted interventions. 相似文献
260.
Mineralogy, morphology, and textural relationships in coatings on quartz grains in sediments in a quartz-sand aquifer 总被引:1,自引:0,他引:1
Zhang S Kent DB Elbert DC Shi Z Davis JA Veblen DR 《Journal of contaminant hydrology》2011,124(1-4):57-67
Mineralogical studies of coatings on quartz grains and bulk sediments from an aquifer on Western Cape Cod, Massachusetts, USA were carried out using a variety of transmission electron microscopy (TEM) techniques. Previous studies demonstrated that coatings on quartz grains control the adsorption properties of these sediments. Samples for TEM characterization were made by a gentle mechanical grinding method and focused ion beam (FIB) milling. The former method can make abundant electron-transparent coating assemblages for comprehensive and quantitative X-ray analysis and the latter technique protects the coating texture from being destroyed. Characterization of the samples from both a pristine area and an area heavily impacted by wastewater discharge shows similar coating textures and chemical compositions. Major constituents of the coating include Al-substituted goethite and illite/chlorite clays. Goethite is aggregated into well-crystallized domains through oriented attachment resulting in increased porosity. Illite/chlorite clays with various chemical compositions were observed to be mixed with goethite aggregates and aligned sub-parallel to the associated quartz surface. The uniform spatial distribution of wastewater-derived phosphorus throughout the coating from the wastewater-contaminated site suggests that all of the coating constituents, including those adjacent to the quartz surface, are accessible to groundwater solutes. Both TEM characterization and chemical extraction results indicate there is a significantly greater amount of amorphous iron oxide in samples from wastewater discharge area compared to those from the pristine region, which might reflect the impact of redox cycling of iron under the wastewater-discharge area. Coating compositions are consistent with the moderate metal and oxy-metalloid adsorption capacities, low but significant cation exchange capacities, and control of iron(III) solubility by goethite observed in reactive transport experimental and modeling studies conducted at the site. 相似文献