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21.
In a recent paper, it was suggested that one of the reasons behind the decline in public regard toward British Columbia's environmental movement was an increasingly negative portrayal of them by the print media. To investigate this suggestion, we undertook a content analysis of print media reporting of forestry and environmental activities in the province's most widely read newspaper, the Vancouver Sun, during 1993 and 1997. We hypothesized that if the print media did contribute to the decline in public regard toward the environmental movement, we would find increasingly negative coverage of the environmental movement over the periods studied. We also hypothesized that this would be accompanied by a decrease in the frequency of articles dealing with issues consistent with the agenda of the environmental movement. We were not able to provide support for our initial hypothesis, nor did we observe a decrease in coverage emphasizing the environmental issues. We did, however, observe an increase in coverage of articles emphasizing typically proindustry issues with many more articles written with a proforestry slant in 1997 than articles written in 1993. This suggests that there had been an agenda shift from environmentally oriented concerns in British Columbia to those associated with the forest industry. As an explanation for the agenda shift, we point to changes in the management and reporting philosophy at the Vancouver Sun, the emergence of an organized, proindustry counterframing strategy by the BC Forest Alliance, and the implementation of several government policies aimed at regulating the activities of the forest industry.  相似文献   
22.
本文详细介绍了英国锅壳锅炉标准(BS2790)从1956年颁布第一版至1992年的第七版,其间的演变、发展的过程。从中观察出他们编制标准的原则:哪些是不变的,哪些是随着生产、科研的发展而变化。  相似文献   
23.
This paper examines the actions and potential of green jobs for the disadvantaged, from the perspective of non-governmental organisations and social entrepreneurs. The populations of interest include: low-income, developmentally challenged, those with mental health or addiction issues, women, and First Nations. Findings indicate that green businesses and social entrepreneurs have uniquely engaged in social training and hiring strategies related to green jobs. The major challenges they face include a lack of policies that support the development of green jobs through social training and hiring. As a result of these findings, an argument is made for combining job and life skills for both disadvantaged populations and the agencies that serve them as well as building the capacity of employers to practise social hiring.  相似文献   
24.
ABSTRACT: The spatial distribution and the temporal and spatial variation of the annual, seasonal, and monthly precipitation in two mountainous watersheds in southwestern British Columbia, Canada, have been analyzed using a detailed database for 1971–1990 in the Capilano and Seymour watersheds. The analysis showed that the precipitation increases up to the mid-position of the watersheds, and then either levels off or decreases. Precipitation on mountain slopes and in the valley at the same distance from the beginning of the slope is similar, and the barrier height is identified as the dominant parameter which influences the precipitation distribution. The temporal variation of the precipitation is the smallest at the mid-position of the watersheds. This variability is the least in the fall and winter and largest in the summer. Correlation between the precipitation accumulations at various stations is large, ranging from 0.80 for the wet period of October-March to 0.65 for the dry period of April-September for distances less than 32 km. Comparison with other studies and the analyses of precipitation and runoff data from coastal British Columbia showed that the results of this study are perhaps general and thus transferable to similar areas in the coastal Pacific Northwest.  相似文献   
25.
ABSTRACT: A network of 32 drought sensitive tree‐ring chronologies is used to reconstruct mean water year flow on the Columbia River at The Dalles, Oregon, since 1750. The reconstruction explains 30 percent of the variability in mean water year (October to September) flow, with a large portion of unexplained variance caused by underestimates of the most severe low flow events. Residual statistics from the tree‐ring reconstruction, as well as an identically specified instrumental reconstruction, exhibit positive trends over time. This finding suggests that the relationship between drought and streamflow has changed over time, supporting results from hydrologic models, which suggest that changes in land cover over the 20th Century have had measurable impacts on runoff production. Low pass filtering the flow record suggests that persistent low flows during the 1840s were probably the most severe of the past 250 years, but that flows during the 1930s were nearly as extreme. The period from 1950 to 1987 is anomalous in the context of this record for having no notable multiyear drought events. A comparison of the flow reconstruction to paleorecords of the Pacific Decadal Oscillation (PDO) and El Nino/Southern Oscillation (ENSO) support a strong 20th Century link between large scale circulation and streamflow, but suggests that this link is very weak prior to 1900.  相似文献   
26.
The primary objective of this study was to evaluate temporal changes in heavy metal content of lower Columbia River sediment following terminated or reduced soluble heavy metal loading from the world's largest lead-zinc refinery and mining districts in the USA and Canada. Sediment cores were collected from two fine sediment depositional sites (∼600 km downstream) in August 1999 and were analyzed for total metal content, texture, and age/dating parameters. Zinc, cadmium and lead contents in 1999 declined by only a factor of two over their depth profile maxima (dated as between 1970 and 1980). In sharp contrast, more than a 10-fold decrease in dissolved metal loading occurred during this same period. Zinc in filtered Columbia River water at downstream locations also declined by > 10-fold, consistent with the reduced upper river solute-metal loading. Once soluble metal releases are reduced or terminated, the solute half-time in Columbia River water is months versus ∼20 yr for adsorbed metals on surficial (or resuspended) bed sediments. The much slower rate of decline for sediment, as compared to the solute phase, is attributed to resuspension, transport and redeposition of irreversibly bound metals from upstream sedimentary deposits. This implies downstream exposure of benthic or particle-ingesting biota can continue for years following source remediation and/or termination of soluble metal releases. Accordingly, contaminant contents of both particulate and solute phases of river water, as well as sediment core sections, are suggested for assessing long-term biotic exposure/response to mitigation activities in the Columbia River and similar fluvial ecosystems.  相似文献   
27.
Recently, occurrences of elevated arsenic concentrations in bedrock groundwaters used for individual and municipal water supplies have been recognised along the mainland coast of southern British Columbia, Canada. An area on Bowen Island (Queen Charlotte Heights community) was chosen to investigate the source(s) of arsenic, geochemical processes controlling its aqueous uptake, the role of geology and structure in the formation of these waters, and the use of hydrogeochemical survey methods for detecting arsenious groundwater regions. Pyrite- arsenopyrite-Cu mineralisation in the Queen Charlotte Heights area is present as veins associated with NE-trending fault zones and as disseminations in marginal breccia and stockwork zones of a ryhodacite porphyry stock. Near surface mineralisation was later altered by supergene events to form minor pyrite- arsenopyrite in a matrix of limonite and clay. Geochemical factors that control the concentration and mobility of arsenic in these groundwaters include: (a) anion exchange of arsenic from clay minerals during cation divalent/univalent exchange processes (water softening) which leads to waters of high pH and high anion exchange capacities; (b) desorption of arsenic from Fe and Al oxyhydroxide minerals during pronounced shifts in pH from acid to alkaline conditions brought on by the water softening process; and (c) stepwise oxidation of arsenopyrite mineralisation to form arsenious sulphate-bearing groundwaters. The inconsistent behaviour of the As3+ and As5+ ions during the complex waterrock interaction processes described above, precludes the use of detailed chemical analyses to predict relative abundances of the more toxic As3+ species. For a full appreciation of the toxic impact of groundwaters containing total arsenic concentrations that are above regulatory guidelines an arsenic speciation analysis is required.  相似文献   
28.
Lee, Se‐Yeun, Alan F. Hamlet, Carolyn J. Fitzgerald, and Stephen J. Burges, 2011. Methodology for Developing Flood Rule Curves Conditioned on El Niño‐Southern Oscillation Classification. Journal of the American Water Resources Association (JAWRA) 47(1):81‐92. DOI: 10.1111/j.1752‐1688.2010.00490.x Abstract: Regional climate varies on interannual and decadal time scales that in turn affect annual streamflows, flood risks, and reservoir storage deficits in mid‐summer. However, these variable elements of the climate system are generally not included in water resources operating policies that attempt to preserve a balance between flood risk and other water resources system objectives. A methodology for incorporating El Niño‐Southern Oscillation (ENSO) information in designing flood control curves is investigated. An optimization‐simulation procedure is used to develop a set of ENSO‐conditioned flood control rule curves that relate streamflow forecasts to flood control evacuation requirements. ENSO‐conditioned simulated flood risk and storage deficits under current operating policy are used to calibrate a unique objective function for each ENSO classification. Using a case study for the Columbia River Basin, we demonstrate that ENSO‐conditioned flood control curves constructed using the optimization‐simulation procedure consistently reduce storage deficits at a number of interrelated projects without increasing flood risk. For the Columbia Basin, the overall improvements in reservoir operations are relatively modest, and (in isolation) might not motivate a restructuring of flood control operations. However, the technique is widely applicable to a wide range of water resources systems and/or different climate indices.  相似文献   
29.
This paper focused on the factors affecting the respiration rate of the digestate taken from a continuous anaerobic two-stage process treating the organic fraction of municipal solid waste (OFMSW). The process involved a hydrolytic reactor (HR) that produced a leachate fed to a submerged anaerobic membrane bioreactor (SAMBR). It was found that a volatile solids (VS) removal in the range 40-75% and an operating temperature in the HR between 21 and 35 °C resulted in digestates with similar respiration rates, with all digestates requiring 17 days of aeration before satisfying the British Standard Institution stability threshold of 16 mg CO2 g VS−1 day−1. Sanitization of the digestate at 65 °C for 7 days allowed a mature digestate to be obtained. At 4 g VS L−1 d−1 and Solid Retention Times (SRT) greater than 70 days, all the digestates emitted CO2 at a rate lower than 25 mg CO2 g VS−1 d−1 after 3 days of aeration, while at SRT lower than 20 days all the digestates displayed a respiration rate greater than 25 mg CO2 g VS−1 d−1. The compliance criteria for Class I digestate set by the European Commission (EC) and British Standard Institution (BSI) could not be met because of nickel and chromium contamination, which was probably due to attrition of the stainless steel stirrer in the HR.  相似文献   
30.
Mass-balance trophic models (Ecopath with Ecosim) are developed for the marine ecosystem of northern British Columbia (BC) for the historical periods 1750, 1900, 1950 and 2000 AD. Time series data are compiled for catch, fishing mortality and biomass using fisheries statistics and literature values. Using the assembled dataset, dynamics of the 1950-based simulations are fitted to agree with observations over 50 years to 2000 through the manipulation of trophic flow parameters and the addition of climate factors: a primary production anomaly and herring recruitment anomaly. The predicted climate anomalies reflect documented environmental series, most strongly sea surface temperature and the Pacific Decadal Oscillation index. The best-fit predator–prey interaction parameters indicate mixed trophic control of the ecosystem. Trophic flow parameters from the fitted 1950 model are transferred to the other historical periods assuming stationarity in density-dependent foraging tactics. The 1900 model exhibited an improved fit to data using this approach, which suggests that the pattern of trophic control may have remained constant over much of the last century. The 1950 model is driven forward 50 years using climate and historical fishing drivers. The resulting ecosystem is compared to the 2000 model, and the dynamics of these models are compared in a predictive forecast to 2050. The models suggest similar restoration trajectories after a hypothetical release from fishing.  相似文献   
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