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41.
The availability of lithium resources for a transition to electric vehicles is a vital topic for transport technology strategy. Recent debate seems to have concluded that there is ‘sufficient’ lithium available, but for the purposes of a technological transition, time matters. It is not simply the quantity of resource that is relevant—the flow rate into society may be a much more difficult constraint and transient events have disrupted heavily concentrated material supply chains in the past. Furthermore, critical assumptions such as the presence of recycling systems may not be justified without policy support. Complacency is therefore not an appropriate stance for a robust evaluation of material risks in the case of lithium. 相似文献
42.
43.
Gleason SM Faucette DT Toyofuku MM Torres CA Bagley CF 《Environmental management》2007,40(6):1016-1024
Acting under the auspices of the US Endangered Species Act, we quantified wind erosion and its effects on rare and common
plant species on a semi-arid military installation in Hawaii. Our goal was to develop management strategies, based on local
data, to aid the conservation of rare and common indigenous plants and their habitats. We collected windblown soil coming
off of roads and other disturbed soils to assess likely impacts to plants occurring at certain heights and distances from
disturbed surfaces. We then subjected plants in a glasshouse to windblown dust treatments, designed from our field data to
simulate erosion events, and evaluated the effect of these treatments on photosynthesis and survival. We also designed several
field experiments to examine the in-situ effects of windblown soil and soil substrate on germination, growth rate, and survival
of indigenous and nonindigenous plants. We conclude from these experiments that most direct effects of windblown soil to plants
can be effectively mitigated by locating roads and training areas at least 40 m from sensitive plant habitats and through
vegetation management to maintain at least 11% aerial cover on disturbed surfaces. Effects of soil type on germination, growth,
and survival was species-specific, emphasizing the importance of species trials prior to, or during, rehabilitation efforts. 相似文献
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47.
Valuing freshwater salmon habitat on the west coast of Canada 总被引:3,自引:0,他引:3
Knowler DJ MacGregor BW Bradford MJ Peterman RM 《Journal of environmental management》2003,69(3):261-273
Changes in land use can potentially reduce the quality of fish habitat and affect the economic value of commercial and sport fisheries that rely on the affected stocks. Parks and protected areas that restrict land-use activities provide benefits, such as ecosystem services, in addition to recreation and preservation of wildlife. Placing values on these other benefits of protected areas poses a major challenge for land-use planning. In this paper, we present a framework for valuing benefits for fisheries from protecting areas from degradation, using the example of the Strait of Georgia coho salmon fishery in southern British Columbia, Canada. Our study improves upon previous methods used to value fish habitat in two major respects. First, we use a bioeconomic model of the coho fishery to derive estimates of value that are consistent with economic theory. Second, we estimate the value of changing the quality of fish habitat by using empirical analyses to link fish population dynamics with indices of land use in surrounding watersheds. In our example, we estimated that the value of protecting habitat ecosystem services is C$0.93 to C$2.63 per ha of drainage basin or about C$1322 to C$7010 per km of salmon stream length (C$1.00=US$0.71). Sensitivity analyses suggest that these values are relatively robust to different assumptions, and if anything, are likely to be minimum estimates. Thus, when comparing alternative uses of land, managers should consider ecosystem services from maintaining habitat for productive fish populations along with other benefits of protected areas. 相似文献
48.
Space shuttle launches produce localized hydrochloric acid deposition. The interaction of solid rocket motor exhaust and deluge
water released on the pad at the time of launch results in the formation of an exhaust cloud. The spatial pattern and extent
of deposition from the launch cloud are predicted by the rocket exhaust effluent diffusion (REED) model. The actual pattern
of deposition has been mapped by field surveys for each shuttle launch since 1981. In this paper we use a geographical information
system (GIS) to compare model predictions with ground patterns for 49 shuttle launches. We also compile cumulative maps of
deposition patterns needed to consider long-term impacts. The direction of launch cloud movement did not differ significantly
from model predictions. The REED model overpredicted both the area that received deposition and the maximum distance from
the launch pad that deposition occurred. Severe vegetation damage was restricted to near-field deposition areas within 1980
m north of each launch pad. Total area impacted from launches has been 87.0 ha around pad 39A and 52.9 ha around pad 39B.
Far-field deposition has caused leaf spotting from acid droplets or aluminum oxide over a wider and more variable area than
near-field. A total of 19,397 ha has received deposition, but 63.6% of this area has received deposition only one time and
92.2% not more than three times. GIS techniques provide means to test spatial models and compile information useful for assessing
cumulative impacts. 相似文献
49.
Francis D. Heliotis Calvin B. DeWitt 《Journal of the American Water Resources Association》1987,23(6):1011-1016
ABSTRACT: Two types of rapid water table responses to rain were observed in a northern Michigan peatland. The first, called the Lisse effect, occurred during rains of high intensity when the infiltrating water acted as a tightly closing lid that forced the water table to rise to the level required to compensate for the pressure increase. The second, called the Wieringermeer effect, was a rapid rise of the water table to the surface due to the conversion of capillary to phreatic water and was always followed by an equally rapid decline after cessation of the rainfall. We simulated these phenomena in the laboratory and estimated the critical parameters that determine their occurrence. The recognition of the importance of the capillary fringe is essential in evaluating the role of wetlands in flood control and in wastewater treatment. 相似文献
50.
The spatial distribution and deposition of lead and zinc emitted from the Trail smelter, British Columbia, Canada, was studied by strategically locating moss bags in the area surrounding the smelter and monitoring the deposition of elements every three months. A combined diffusion/distribution model was applied to estimate the relative contribution of stack-emitted material and material emitted from the secondary sources (e.g., wind-blown dust from ore/slag storage piles, uncovered transportation/trucking of ore, and historical dust). The results indicate that secondary sources are the major contributor of lead and zinc deposited within a short distance from the smelter. Gradually, the stack emissions become the main source of Pb and Zn at greater distances from the smelter. Typical material originating from each source was characterized by SEM/EDX, which indicated a marked difference in their morphology and chemical composition. 相似文献