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81.
This paper examines possible ozone-induced foliar injury to ponderosa pine areas in the Rincon Mountains of southern Arizona from 1972 to 1992. Spatiotemporal differences in a satellite-derived vegetation index (VI) are examined with respect to antecedent moisture conditions, temporal variations in ozone exposure levels, and measured foliar injury values from 1985. Seasonal ozone exposure levels (SUM60 and W126) increased from 1982 to 1998 and were significantly correlated (r = 0.49 and 0.53, α= 0.05) with annual population totals in the Tucson area. Extensive masking of satellite images from 1972, 1986, and 1992 resulted in two optimal change detection areas, with one site, TVWMica, exposed mostly to the Tucson air pollution plume, while the other site, EMica, was more protected from Tucson-derived pollution. An overall increase in VI from 1972 to 1992 at both sites appears to have been caused by an increase in moisture availability. Larger foliar injury values in 1985 were associated with a smaller increase in VI (i.e., a smaller increase in green leaf biomass) from 1972 to 1986. From 1972 to 1986 and from 1986 to 1992, VI values at TV/WMica increased at a slower rate compared to those at EMica. The reduced increase in “green-up” may have been caused partially by ozone-induced foliar injury and resulting decreases in green leaf biomass. However, these spatial differences in VI values may have also been caused by a number of other factors. Results nevertheless reveal the strong possibility of distinct, topographically based, spatial variations in ozone-induced foliar injury within the Rincons.  相似文献   
82.
Jan Karlas 《环境政策》2017,26(5):825-846
Why do some states and state coalitions, acting within the United Nations Framework Convention on Climate Change (UNFCCC), support harder legalization of the global climate regime? In order to explain why, the effects of four causal factors are considered: climate vulnerability, the emission intensity of the national economy, a state’s power position, and socialization into climate norms. To identify the legalization positions of UNFCCC actors, an original content analysis is conducted of all the submission and meeting statements made at the Ad Hoc Working Group on the Durban Platform during the years 2012–2015. Subsequently, a qualitative comparative analysis is carried out to find out which combinations of the causal factors offer a sufficient explanation for the analyzed outcome, leading to the identification of two causal pathways that lead states to endorse harder legalization of the climate regime.  相似文献   
83.
This paper examines and compares the management practices and regulatory approaches used by the Mid-Atlantic States of Delaware, Maryland, New Jersey, and Pennsylvania for improving the quality of storm-water runoff. Such practices range from simple extended detention criteria in Pennsylvania through the BMP credit system used by Maryland, to the latest "green technology" methods promoted in Delaware and the recharge, quality and peak reduction approaches of New Jersey. All practices are designed to meet EPA requirements for total suspended solids (TSS) removal, but verification of performance is not required. More sophisticated methods of evaluating TSS removal that can be used for engineering design purposes are needed.  相似文献   
84.
美国是世界上最先对固定式发动机污染物排放进行专门控制的国家,其固定式发动机排放法规基于最佳示范技术而制定。对于固定压燃式发动机,其排放法规与非道路移动机械用和船用压燃式发动机排放法规充分协调,该法规对“发动机”和“设施”均提出排气污染物排放控制要求,同时,对所用的燃油也进行了规定。在研究排放法规的基础上,分析了美国固定式发动机排放控制的特点,提出了我国制定固定式发动机排放标准的建议。  相似文献   
85.
86.
Many taxonomic groups successfully exploit groundwater environments and have adapted to a subterranean (stygobiotic) existence. Among these groups are freshwater gastropods (stygosnails), which represent a widespread and taxonomically diverse component of groundwater ecosystems in North America. However, owing to sampling difficulty and lack of targeted study, stygosnails remain among the most understudied of all subterranean groups. We conducted a literature review to assess the biodiversity and geographic associations of stygosnails, along with the threats, management activities, and policy considerations related to the groundwater systems they inhabit. We identified 39 stygosnail species known to occur in a range of groundwater habitats from karst regions in the United States and Mexico. Most stygosnails exhibit extreme narrow-range endemism, resulting in a high risk of extinction from a single catastrophic event. We found that anthropogenically driven changes to surface environments have led to changes in local hydrology and degradation of groundwater systems inhabited by stygosnails such as increased sedimentation, introduction of invasive species, groundwater extraction, or physical collapse of water-bearing passages. Consequently, 32 of the 39 described stygosnail species in the United States and Mexico have been assessed as imperiled under NatureServe criteria, and 10 species have been assessed as threatened under International Union for Conservation of Nature criteria. Compared with surface species of freshwater snails, stygosnail conservation is uniquely hindered by difficulties associated with accessing subterranean habitats for monitoring and management. Furthermore, only three species were found to have federal protection in either the United States or Mexico, and current laws regulating wildlife and water pollution at the state and federal level may be inadequate for protecting stygosnail habitats. As groundwater systems continue to be manipulated and relied on by humans, groundwater-restricted fauna such as stygosnails should be studied so unique biodiversity can be protected.  相似文献   
87.
Much quantitative research examining the determinants of the ecological footprint has been conducted cross-nationally, where data on cross-boundary flows have been readily available. While local-level studies of the footprint do exist for specific localities, most quantitative research at this scale has examined direct environmental impacts attributed to the internal activities of the locality, for instance, carbon emissions. Our analysis builds on this previous work by exploiting a local-level carbon footprint dataset with coverage for 28,321 zip codes across the United States. Following prior research, we focus on the effect of local affluence, measured in terms of median household income. In spatial regression models, we regress the per capita carbon footprint on local affluence, controlling for a variety of other factors. Consistent with previous work, we find that affluence is positively correlated the carbon footprint and there is no evidence of an environmental Kuznets curve. In the conclusion, we review the results of the study and discuss their implications for policy, specifically in terms of cross-boundary environmental problems.  相似文献   
88.
为提高我国安全生产标准化水平,进一步发挥标准的技术支撑作用,收集了美国职业安全健康标准有关资料,对美国职业安全健康标准的分类、管理机构和管理模式、标准体系构成等进行了系统的梳理,归纳了美国金属非金属矿山(包括露天和井下)职业安全健康技术法规体系和职业安全健康技术法规体系(矿山除外)的要素构成,以及各要素规范的主要技术内容,分析了美国职业安全健康标准及标准体系的特点。为完善我国安全生产标准体系,加强标准制修订工作以及相关标准科研工作提供依据和参考  相似文献   
89.
The numerous formulated products which are introduced to the market consist of chemical ingredients that may cause various safety and health hazards to the consumers. Therefore, it is extremely important to practice a systematic methodology to formulate products with acceptable safety and health performances. This work presents an index-based methodology to assess the safety and health hazards of the ingredients during the early formulation stage of product design. Hence, new inherent safety and health sub-indexes are introduced to improve the current safety and health hazards that are needed in formulated product design. The inherent safety and health sub-indexes are assigned with scores based on the degree of potential hazards. A higher score indicates a higher safety risk or severe health effect, and vice versa. The proposed methodology will greatly assist the users to identify the adverse safety and health effects caused by the ingredients. Hence, it is pivotal to eliminate or reduce the safety and health impacts from product usage. A case study on common ingredients used in the formulation of paint is presented on this study to describe the proposed method.  相似文献   
90.
Abstract: Tree rings offer a means to extend observational records of streamflow by hundreds of years, but dendrohydrological techniques are not regularly applied to small tributary and headwaters gages. Here we explore the potential for extending three such gage records on small streams in the Wind River drainage of central Wyoming, United States. Using core samples taken from Douglas fir (Pseudotsuga menziesii), piñon pine (Pinus edulis), and limber pine (Pinus flexilis) at 38 sites, we were able to reconstruct streamflows for the headwaters of the Wind River back to 1672 AD or earlier. The streamflow reconstructions for Bull Lake Creek above Bull Lake; the Little Popo Agie River near Lander, Wyoming; and Wind River near Dubois, Wyoming explained between 40% and 64% of the observed variance, and these extended records performed well in a variety of statistical verification tests. The full reconstructions show pronounced inter‐annual variability in streamflow, and these proxy records also point to the prevalence of severe, sustained droughts in this region. These reconstructions indicate that the 20th Century was relatively wet compared to previous centuries, and actual gage records may capture only a limited subset of potential natural variability in this area. Further analyses reveal how tree‐ring based reconstructions for small tributary and headwaters gages can be strongly influenced by the length and quality of calibration records, but this work also demonstrates how the use of a spatially extensive network of tree‐ring sites can improve the quality of these types of reconstructions.  相似文献   
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