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581.
Yaser Abunnasr Elisabeth M. Hamin Elizabeth Brabec 《Journal of Environmental Planning and Management》2015,58(1):135-155
There is a pressing need for municipalities and regions to create urban form suited to current as well as future climates, but adaptation planning uptake has been slow. This is particularly unfortunate because patterns of urban form interact with climate change in ways that can reduce, or intensify, the impact of overall global change. Uncertainty regarding the timing and magnitude of climate change is a significant barrier to implementing adaptation planning. Focusing on implementation of adaptation and phasing of policy reduces this barrier. It removes time as a decision marker, instead arguing for an initial comprehensive plan to prevent maladaptive policy choices, implemented incrementally after testing the micro-climate outcomes of previous interventions. Policies begin with no-regrets decisions that reduce the long-term need for more intensive adaptive actions and generate immediate policy benefits, while gradually enabling transformative infrastructure and design responses to increased climate impacts. Global and local indicators assume a larger role in the process, to evaluate when tipping points are in sight. We use case studies from two exemplary municipal plans to demonstrate this method's usefulness. While framed for urban planning, the approach is applicable to natural resource managers and others who must plan with uncertainty. 相似文献
582.
Testing the field of dreams hypothesis: functional responses to urbanization and restoration in stream ecosystems 总被引:1,自引:0,他引:1
As catchments become increasingly urban, the streams that drain them become increasingly degraded. Urban streams are typically characterized by high-magnitude storm flows, homogeneous habitats, disconnected riparian zones, and elevated nitrogen concentrations. To reverse the degradation of urban water quality, watershed managers and regulators are increasingly turning to stream restoration approaches. By reshaping the channel and reconnecting the surface waters with their riparian zone, practitioners intend to enhance the natural nutrient retention capacity of the restored stream ecosystem. Despite the exponential growth in stream restoration projects and expenditures, there has been no evaluation to date of the efficacy of urban stream restoration projects in enhancing nitrogen retention or in altering the underlying ecosystem metabolism that controls instream nitrogen consumption. In this study, we compared ecosystem metabolism and nitrate uptake kinetics in four stream restoration projects within urban watersheds to ecosystem functions measured in four unrestored urban stream segments and four streams draining minimally impacted forested watersheds in central North Carolina, U.S.A. All 12 sites were surveyed in June through August of 2006 and again in January through March of 2007. We anticipated that urban streams would have enhanced rates of ecosystem metabolism and nitrate uptake relative to forested streams due to the increases in nutrient loads and temperature associated with urbanization, and we predicted that restored streams would have further enhanced rates for these ecosystem functions by virtue of their increased habitat heterogeneity and water residence times. Contrary to our predictions we found that stream metabolism did not differ between stream types in either season and that nitrate uptake kinetics were not different between stream types in the winter. During the summer, restored stream reaches had substantially higher rates of nitrate uptake than unrestored or forested stream reaches; however, we found that variation in stream temperature and canopy cover explained 80% of the variation across streams in nitrate uptake. Because the riparian trees are removed during the first stage of natural channel design projects, the restored streams in this study had significantly less canopy cover and higher summer temperatures than the urban and forested streams with which they were compared. 相似文献
583.
584.
Elizabeth K. Mackley Richard A. Phillips Janet R. D. Silk Ewan D. Wakefield Vsevolod Afanasyev Robert W. Furness 《Marine Biology》2011,158(2):429-438
Despite the recent burgeoning in predator tracking studies, few report on seabird activity patterns, despite the potential
to provide important insights into foraging ecology and distribution. In the first year-round study for any small petrel,
we examined the activity patterns of the white-chinned petrel Procellaria aequinoctialis based on data from combination geolocator-immersion loggers deployed on adults at South Georgia. The petrels were highly
nocturnal, flying for greater proportions of darkness than any large procellarid studied so far, except the light-mantled
albatross Phoebetria palpebrata. Flight bout durations were short compared with other species, suggesting a dominant foraging mode of small-scale searching
within large prey patches. When migrating, birds reduced the proportion of time on the water and increased flight bout duration.
Activity patterns changed seasonally: birds flew least during the nonbreeding period, and most frequently during chick-rearing
in order to meet higher energy demands associated with provisioning offspring. The degree of their response to moonlight was
also stage dependent (greatest in nonbreeding, and weakest in incubating birds), a trait potentially shared by other nocturnal
petrels which will have repercussions for feeding success and prey selection. For the white-chinned petrel, which is commonly
caught in longline fisheries, these results can be used to identify periods when birds are most susceptible to bycatch, and
therefore when use of mitigation and checking for compliance is critical. 相似文献
585.
Routti H Letcher RJ Born EW Branigan M Dietz R Evans TJ Fisk AT Peacock E Sonne C 《Journal of environmental monitoring : JEM》2011,13(8):2260-2267
Spatial trends and comparative changes in time of selected trace elements were studied in liver tissue from polar bears from ten different subpopulation locations in Alaska, Canadian Arctic and East Greenland. For nine of the trace elements (As, Cd, Cu, Hg, Mn, Pb, Rb, Se and Zn) spatial trends were investigated in 136 specimens sampled during 2005-2008 from bears from these ten subpopulations. Concentrations of Hg, Se and As were highest in the (northern and southern) Beaufort Sea area and lowest in (western and southern) Hudson Bay area and Chukchi/Bering Sea. In contrast, concentrations of Cd showed an increasing trend from east to west. Minor or no spatial trends were observed for Cu, Mn, Rb and Zn. Spatial trends were in agreement with previous studies, possibly explained by natural phenomena. To assess temporal changes of Cd, Hg, Se and Zn concentrations during the last decades, we compared our results to previously published data. These time comparisons suggested recent Hg increase in East Greenland polar bears. This may be related to Hg emissions and/or climate-induced changes in Hg cycles or changes in the polar bear food web related to global warming. Also, Hg:Se molar ratio has increased in East Greenland polar bears, which suggests there may be an increased risk for Hg(2+)-mediated toxicity. Since the underlying reasons for spatial trends or changes in time of trace elements in the Arctic are still largely unknown, future studies should focus on the role of changing climate and trace metal emissions on geographical and temporal trends of trace elements. 相似文献
586.
Problem
Information about where nonfatal unintentional injuries occur is limited, but bathrooms commonly are believed to be a hazardous location.Methods
Data from a nationally representative sample of hospital emergency departments (ED) was used to quantify and characterize nonfatal unintentional bathroom injuries among people aged ≥ 15 years.Results
In 2008, an estimated 234,094 nonfatal bathroom injuries were treated in EDs. Most injuries (81.1%) were caused by falls and 37.3% of injuries occurred when bathing, showering, or getting out of the tub or shower. Both injury and hospitalization rates increased with age.Summary
These results suggest that bathrooms tend to be most hazardous for persons in the oldest age groups.Impact on Industry
Bathroom injuries among all household members might be reduced by increasing awareness about potentially hazardous activities in the bathroom combined with simple environmental changes such as adding grab bars inside and outside the tub or shower. 相似文献587.
Kiwon Park Karl S. Rosengren Gavin P. Horn Denise L. Smith Elizabeth T. Hsiao-Wecksler 《Safety Science》2011,49(5):719-726
Each year, roughly 11,000 firefighters are injured as a result of slips, trips and falls, which account for over 25% of all fireground injuries. Wearing personal protective equipment (PPE) can increase risk of fall-related injuries due to its weight, restrictiveness, and increased heat stress. Modification of PPE may serve to mitigate firefighter injuries related to loss of balance and falls. We examined the effects of choosing ‘enhanced’ protective clothing (lightweight, breathable, and less restrictive compared to typical firefighting PPE) and simulated firefighting tasks (18-min bout over four activities) on subsequent gait performance. To assess the effect of wearing protective clothing and firefighting activity, seven gait parameters and three movement errors were assessed during level and obstacle-crossing walking tasks. Forty-four firefighters wore one of two types of PPE (‘Standard’, ‘Enhanced’) during three testing conditions (baseline in station uniform, pre-firefighting activity in PPE, and post-firefighting activity in PPE). The effect of donning any PPE was found to significantly impair gait performance. Fatigue may impact effective mobility since more movement errors were observed during post-activity than pre-activity assessments. Although the Enhanced PPE did not lead to any significant differences in gait parameters compared to Standard PPE, participants in Enhanced PPE made twice as many movement errors, potentially attributed to lack of familiarity with the gear. These results suggest that wearing firefighting PPE and heat-stress induced fatigue are associated with reduced gait performance and increased risk for tripping over obstacles. 相似文献
588.
589.
Jesper Slver Schou Jesper Bladt Rasmus Ejrns Maria Nygrd Thomsen Suzanne Elizabeth Vedel Camilla Fljgaard 《Ambio》2021,50(5):1047
Policies aiming at improving biodiversity often consist of costly agri-environmental schemes, i.e. subsidized grazing or mowing of semi-natural areas. However, these practices have widely been found to be insufficient to mitigate biodiversity loss. Rewilding, i.e. restoring natural processes in self-sustaining biodiverse ecosystems, has been proposed as an alternative and is hypothesized to be a more cost-efficient approach to promote biodiversity conservation. Rewilding requires the availability of large natural areas which are not allocated for farming, forestry, and infrastructure to avoid potential conflicts over the use of the area. We perform an ex-ante private cost–benefit analysis of the establishment of four large nature reserves for rewilding in Denmark. We analyse the economic effects of changing from summer grazing in nature areas in combination with cultivated fields and forestry to the establishment of nature reserves in four case areas. We consider two scenarios involving conversion of agriculture and forestry areas into natural areas in combination with either extensive year-round cattle grazing or rewilding with wild large herbivores. In two case areas, it appears possible to establish large nature areas without incurring extra costs. Additionally, rewilding further reduces costs compared to year-round cattle grazing. Two opposing effects were dominant: increased economic rent occurred from the shift from summer grazing to year-round grazing or rewilding, while cessation of agriculture and forestry caused opportunity costs. 相似文献
590.
Morphological changes within the porous architecture of laboratory scale zero valent iron (ZVI) permeable reactive barriers (PRBs), after exposure to different groundwater conditions, have been quantified experimentally for different ZVI/sand ratios (10%, 50% and 100%, W/W) with the aim of inferring porosity changes in field barriers. Column studies were conducted to simulate interaction with different water chemistries, a synthetic groundwater, acidic drainage and deionised (DI) water as control. Morphological changes, in terms of pore size and distribution, were measured using X-ray computed tomography (CT). CT image analysis revealed significant morphological changes in columns treated with different water chemistries. For example, 100% ZVI (W/W) columns had a higher frequency of small pores (0.6 mm) was observed in ZVI grains reacted with typical groundwater, resulting in a porosity of 27%, compared to 32% when exposed to DI water. In comparison, ZVI grains treated with the acidic drainage had higher porosity (44%) and larger average pore size (2.8 mm). 10% ZVI PRB barrier material had the highest mean porosity (56%) after exposure to any water chemistry whilst 100% ZVI (W/W) columns always had the lowest (34%) with the 50% ZVI (W/W) in between (40%). These results agree with previously published PRB field data and simultaneously conducted geochemical monitoring and mass balance calculation, indicating that both the geochemical and hydraulic environment of the PRB play an important role in determining barrier lifespan. This study suggests that X-ray CT image analysis is a powerful tool for studying the detailed inter pores between ZVI grains within PRBs. 相似文献