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1.
Dynamics and Causation of Environmental Equity, Locally Unwanted Land Uses, and Neighborhood Changes
Feng Liu 《Environmental management》1997,21(5):643-656
/ Why are some environmental risks distributed disproportionately in the neighborhoods of the minorities and the poor? A hypothesis was proposed in a recent study that market dynamics contributed to the current environmental inequity. That is, locally unwanted land uses (LULUs) make the host communities home to more poor people and people of color. This hypothesis was allegedly supported by a Houston case study, whereby its author analyzed the postsiting changes of the socioeconomic characteristics of the neighborhoods surrounding solid waste facilities. I argue that such an analysis of postsiting changes alone is insufficient to test the causation hypothesis. Instead, I propose a conceptual framework for analysis of environmental equity dynamics and causation. I suggest that the presiting neighborhood dynamics and the characteristics of control neighborhoods be analyzed as the first test for the causation hypothesis. Furthermore, I present theories of neighborhood change and then examine alternative hypotheses that these theories offer for explaining neighborhood changes and for the roles of LULUs in neighborhood changes. These alternative hypotheses should be examined when analyzing the relationship between LULUs and neighborhood changes in a metropolitan area. Using this framework of analysis, I revisited the Houston case. First, I found no evidence that provided support for the hypothesis that the presence of LULUs made the neighborhoods home to more blacks and poor people, contrary to the conclusion made by the previous study. Second, I examined alternative hypotheses for explaining neighborhood changes-invasion-succession, other push forces, and neighborhood life-cycle; the former two might offer better explanation.KEY WORDS: Environmental equity and justice; Locally unwanted lane uses; Siting; Market dynamics; Invasion-succession; Neighborhood changes 相似文献
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本文对某铀矿职业工人和非职业工人头发中的总β、总α放射性水平和铀、钍含量进行了分析测定.结果表明,该矿工人体内铀和钍的蓄积量均在正常放射性本底水平范围内,从头发中检验未观察到工人体内铀、钍放射性水平有明显的升高. 相似文献
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复杂矿井通风系统角联风路自动识别方法的研究 总被引:4,自引:0,他引:4
角联风路的识别与稳定性分析是矿井通风系统稳定性与可靠性分析理论中的核心内容之一。笔者对通风系统角联风路进行了深入的研究;分析了通路法的局限性,简化了角联风路的数学模型,提出了快速、准确、灵活的角联风路自动识别的新方法——节点位置法;编写了角联风路自动识别软件,并应用现场数据进行测试,将其结果与通路法的结果进行了比较分析;证明了节点位置法是切实可行的。 相似文献
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VanWoert ND Rowe DB Andresen JA Rugh CL Fernandez RT Xiao L 《Journal of environmental quality》2005,34(3):1036-1044
Urban areas generate considerably more stormwater runoff than natural areas of the same size due to a greater percentage of impervious surfaces that impede water infiltration. Roof surfaces account for a large portion of this impervious cover. Establishing vegetation on rooftops, known as green roofs, is one method of recovering lost green space that can aid in mitigating stormwater runoff. Two studies were performed using several roof platforms to quantify the effects of various treatments on stormwater retention. The first study used three different roof surface treatments to quantify differences in stormwater retention of a standard commercial roof with gravel ballast, an extensive green roof system without vegetation, and a typical extensive green roof with vegetation. Overall, mean percent rainfall retention ranged from 48.7% (gravel) to 82.8% (vegetated). The second study tested the influence of roof slope (2 and 6.5%) and green roof media depth (2.5, 4.0, and 6.0 cm) on stormwater retention. For all combined rain events, platforms at 2% slope with a 4-cm media depth had the greatest mean retention, 87%, although the difference from the other treatments was minimal. The combination of reduced slope and deeper media clearly reduced the total quantity of runoff. For both studies, vegetated green roof systems not only reduced the amount of stormwater runoff, they also extended its duration over a period of time beyond the actual rain event. 相似文献
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20世纪长江的3次巨洪 总被引:10,自引:0,他引:10
分析了形成20世纪长江3次巨洪的3个遥相关因子:(1)太阳黑子活动;(2)厄尔尼诺事件,(3)青藏高原南部大震。依据长江巨洪和遥相关因子的基本事实,讨论了长江发生巨洪的统计规律。指出当3个因子的出现时间互相重叠时,长江很可能发生巨洪,这对长江巨洪的超长期预测具有重要的指导作用。 相似文献
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TMA改性粘土矿物对模拟地下水中苯系物的吸附 总被引:8,自引:0,他引:8
用短链季铵盐阳离子表面活性剂四甲基铵离子(TMA)改性膨润土和凹凸棒土,研究它们对模拟地下水中苯系物的吸附作用。二种TMA改性粘土矿物均可以有效地吸附模拟地下水中的苯系物,吸附机理较复杂,主要以表面吸附为主。 相似文献
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人与自然的和谐是人类社会可持续发展的实践基础和核心议题。本文着重从“生产剩余”和“消费剩余”新的认识视觉 ,通过构建物流循环结构和剖析人与自然的相依关系 ,探索两者之间物质、能量转化的协同机理与和谐准则 ,进而提出了相应的实践对策。 相似文献