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991.
堆积层滑坡沿基岩面再次滑动是一种常见的地质灾害。本文着重阐述了基岩面形状对堆积层滑坡剧滑后堆积特征、复活过程中的坡形重塑及其变形特征的影响。 相似文献
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993.
目的使用电磁仿真软件XFDTD,研究雷电磁脉冲(LEMP)对便携计算机的电磁危害。方法给出腔体内部采样点处的电场时域波形图和截面的电场分布图,计算腔体内不同位置处的屏蔽效能和瞬时坡印廷矢量的大小,分析雷电电磁脉冲与腔体正面孔阵和侧面孔洞的耦合以及孔洞的互耦合。结果雷电电磁脉冲会与入射正面和侧面上的小孔发生不同程度的耦合。雷电电磁脉冲对腔体内部的电磁危害很小,电磁能量主要被限制在开孔附近,腔体中心处受到的影响最小。开孔面积越大,耦合进的电磁能量越多。相邻孔洞之间的互耦合效应使得腔体的屏蔽性变差。结论雷电电磁脉冲对便携计算机的危害一般很小。 相似文献
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为了定量得到赤潮危险度评估结果,在渤海湾赤潮重点监控区现场实测数据的基础上,采用已建立的基于营养盐的中肋骨条藻生长耐受性模型及赤潮危险度评估方法,评估中肋骨条藻生长的耐受性特征及其引发赤潮的危险度,并对评估方法的适用性和合理性进行验证.结果表明,在监测期间(2006年7月29日至8月1日),中肋骨条藻赤潮危险度随着监测... 相似文献
996.
在回顾和评述防灾减灾经济效益评价方面的理论研究基础上,以秭归县为例分析了三峡库区地质灾害防治的经济效益,认为国家对三峡库区投入的地质灾害治理资金发挥巨大的经济效益,保障了库区人民的生命财产安全,并指出了目前灾害防治经济效益评价中的不足。 相似文献
997.
Veronica M. Ngole-Jeme 《Ambio》2016,45(3):374-386
Soils enriched with heavy metals from vehicular emission present a significant exposure route of heavy metals to individuals using unpaved roads. This study assessed the extent of Cd, Cr, Co, Cu, Ni, Pb and Zn contamination of soils along unpaved roads in Cameroon, and the health risks presented by incidental ingestion and dermal contact with the soils using metal contamination factor (CF) pollution load index, hazard quotients (HQ) and chronic hazard index (CHI). CF values obtained (0.9–12.2) indicate moderate to high contamination levels. HQ values for Cr, Cd and Pb exceeded the reference doses. Moderate health hazard exists for road users in the areas with intense anthropogenic activities and high average daily traffic (ADT) volume according to CHI values (1–4) obtained. The economy and quality of life in cities with unpaved roads could be threatened by health challenges resulting from long-term exposure to heavy metal derived from high ADT volumes. 相似文献
998.
《Environmental Hazards》2013,12(2):154-170
Previous research indicates that people's perception of risk from a particular hazard positively influences their adoption of effective mitigation strategies and responses. This research investigates the risk perceptions of people living downstream from Tsho Rolpa Glacial Lake of Nepal. Field surveys revealed that people living beneath the Tsho Rolpa glacial lake possess a low risk perception despite the probability of a glacial lake outburst at their location. Further investigation reveals that many individuals have made no adjustments in response to the potential disaster. The low risk perception on the part of the riverine population is chiefly attributed to the cry-wolf effect of the 1997 evacuation that followed an inaccurate prediction of a Tsho Rolpa outburst. Previous remediation structures were kept in place, but appear to have created a false sense of security among those at risk. This overconfidence in the rudimentary efforts employed thus far is illustrated by the fact that many residents have moved their infrastructure even closer to the river channel in recent years. Partial mitigation efforts have muted people's perceptions of the environmental risk and have therefore increased the vulnerability of the communities to a probable outburst flood. 相似文献
999.
大渡河上游某水电站库区滑坡的危险性评价 总被引:1,自引:0,他引:1
大渡河上游某拟建水电站突出的工程地质问题之一为库区内2个大型滑坡的稳定性。通过对滑坡的工程地质条件、变形特征、影响因素及成因机制分析,在定性分析的基础上,选择代表性剖面,分多种工况条件,利用极限平衡法对滑坡整体稳定性进行了定量计算。并在此基础上采用能量法、美国土木工程学会建议法和水科院经验公式法对局部滑体的滑动速度和产生的涌浪高度进行了预测计算和分析,由此得出滑坡对大坝安全运营和库区居民的危害程度的危险性评价。 相似文献
1000.
Toxic or hazardous substances pose two types of risks in the environment, namely `short-term or acute risk' and `long-termor chronic risk'. The short-term risk is associated with the one-time acute exposure to potentially hazardous substancesaccidentally released in the environment, whereas the long-termrisk is resulted from continuous exposure to potentially harmfulsubstances present in different environmental media. This articledeals with the assessment of potential health risks related to certain carcinogens and non-carcinogens (e.g. cadmium, chromiumand nickel) present in three environmental media, viz. air, waterand food in different Indian states (regions). Appropriate dose-response models have been identified and used for this purpose with the assumptions and input data as per the Indian context. Mean values of ambient air concentration levels of Cd,Cr and Ni have been used to estimate the individual and societalrisks of extra cancer in different states of India. The hazardquotients and hazard index representing the non-carcinogenic chronic health effects caused by chromium and cadmium due to their long-term exposure through water and food have also beenestimated. The risk results have been compared with the diseasesurveillance data. A definite correlation between the estimatedrisk results and the reported number of lung cancer cases and chronic liver diseases have been observed in different regions. As a matter of fact, it is not possible to derive precise risk estimates due to various uncertainties included both in availabledata and in the models which are used to calculate potency factors and effective concentration. However, average risk levelsas estimated and presented in this article are quite useful forplanning purposes. 相似文献