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SCOTT WILLIAM HOEFLE 《Geographical Research》2014,52(2):198-211
Critical global political ecology and critical cultural political economy approaches are used in a study involving decades of research to evaluate the changing relationship between fisher livelihoods, seashore tourism, and urban industrial development in an economically dynamic region of coastal Brazil. As the metropolitan area of Rio de Janeiro expanded and encompassed fishing communities, socio‐environmental transformations created threats to fisher ways of life, opened new multi‐functional opportunities, and also introduced unrelated juxtaposed activities. As stocks fell due to overfishing and urban industrial pollution over the last two decades, small‐scale inshore fishing declined in the bay–lagoon systems located to the east and south‐west of Rio de Janeiro. Tourism increased but proved to be a poor substitute for declining fishing activities because it and other new multi‐functional activities rarely aggregated significant value to local livelihoods. Consequently, only a small minority of fishers benefited and remained on the islands and sand spits, while the great majority left for the mainland. New cultural and environmental functions were also absent, so that of the types of multi‐functionality identified by Wilson and Holmes, those present in the study area are weak and basically serve outside urban production and consumption interests. 相似文献
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Two‐phase flow and near‐critical phenomena are likely to enhance energy transport in high‐temperature hydrothermal systems. We present a series of two‐dimensional simulations of two‐phase flow of pure water at near‐critical conditions. The results show that at near‐critical conditions, two‐phase convection can be more efficient in transporting energy than single‐phase convection. The highest heat fluxes are attained when two‐phase heat‐pipes form near the bottom boundary, recharging the root of the upflow zone and thereby enabling the formation of broad upflow regions. When the system becomes more vapor‐dominated, it loses this ability, upflow zones become narrower and the energy efficiency drops to more moderate values. 相似文献
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Gang Meng G. Brent Hall Mary E. Thompson Patrick Seliske 《The Canadian geographer》2013,57(2):154-172
This study assesses the overall spatial variations and neighbourhood‐level “hot spots” of low birth weight and preterm birth incidence within three public health units in Ontario, Canada. The analysis uses a stepwise approach of intra‐class correlation analysis, a spatial scan statistic, and multilevel spatial modeling. Results show that neighbourhood level variation accounts for only 2–3 percent of the total variation of adverse birth outcomes in the study area. However, strong spatial autocorrelation is observed at the neighbourhood level, and spatial clusters of relatively high adverse birth outcome rates exist in areas that are associated with environmental risks, including pollution sources and proximity to highways. Thus, although estimated neighbourhood impacts on adverse birth outcomes are small compared with those of individual‐level risks, local high potential environmental risk areas are identifiable. Environmental surveillance and spatial statistical analysis should be conducted regularly by local health authorities to identify and monitor the impact of environmental changes on health in general and on birth outcomes in particular. Specific community‐oriented health interventions may be required to reduce observed local health impacts. 相似文献
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中国考古学学科发展调研报告 总被引:2,自引:0,他引:2
全国社科规划考古学科调查组 《华夏考古》2001,(3):105-112
“九五” 期间,中国考古学在田野考古上又有许多重要的发现,各个领域的综合研究和专题研究也有所进展。研究课题多样化,研究视野不断开阔。现代科学技术手段在中国考古学研究中的进一步应用,取得了不少新成果。新的发现与研究,推进了学科自身的发展;同时,对中国历史及其他相关学科的研究也产生着越来越重要的影响。 中国考古学在“十五”期间应重视学风建设;进一步加强理论与方法论的研究;田野工作应进一步提高科学水平;加强课题意识,集中力量解决关键性问题,同时协调田野考古工作的布局和研究工作的重点;提倡多学科合作研究。… 相似文献
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Next to agriculture, road development is one of the most significant sources of stress to wetlands in Prairie Canada. However, there currently exists limited guidance for incorporating direct, indirect, and induced effects to wetlands in impact assessment and mitigation planning for small and often routine developments, including access roads or highway improvement initiatives. Based on the Louis Riel Trail, Highway 11 North twinning project in Saskatchewan, Canada, this article demonstrates a methodological approach and decision support framework for assessing and managing direct, indirect, and induced effects to wetlands from linear developments. No regulatory‐based environmental assessment was required for the highway project; effects were deemed to be insignificant under current wetland mitigation practices. However, our results show that 1115 ha of potentially affected wetlands are located within a 500 m impact zone on either side of the proposed highway. More than 50 percent of these wetlands are seasonal, less than 1 ha in size, and typically not included in mitigation planning. An expert‐based multi‐criteria evaluation of impact and mitigation options for wetlands in the study area indicated “no net loss” as a planning priority, and a preference for a spatially ambitious mitigation plan focused on direct, indirect, and potentially induced impacts. In practice, however, mitigation is often restrictive, focused on mitigating only direct impacts within the project's right‐of‐way, in this case less than 50 ha of wetlands, resulting in the potential for significant net loss of wetland habitat and function. If the risk to wetlands is to be given due consideration in project planning and development for roads and road improvement initiatives, then structured assessment methods and decision support frameworks should be sensitive to the time and resource constraints of small projects and screening‐type assessments. This requires also that wetland mitigation policies are developed and implementation plans formulated as part of project planning and assessment initiatives for linear developments. 相似文献
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Accurate mapping of land use/cover conditions provides essential information for managing natural resources and is critical for further examination of land use/cover change and its subsequent impacts on the environment. Remote sensing offers a means of acquiring land use/cover data in a timely manner, with optical remote sensing images commonly being used in land use/cover related studies. The persistent cloud cover during the rainy season in Southeast Asia, however, presents a challenge for using optical images in land use/cover mapping. Integrating multi‐sensor images of different spectral domains is thus desirable because more information can be extracted to improve the mapping accuracy. The purpose of this study is to assess the potential of using multi‐sensor data sets for land use/cover mapping in a tropical mountainous area in northern Thailand. Optical data from Landsat Thematic Mapper, radar images from Advanced Land Observing Satellite/Phased Array type L‐band Synthetic Aperture Radar (PALSAR), and topographical data were used, providing complementary information on land use/cover. Classification and accuracy assessment were conducted for 12 different combinations of the data sets. The results suggested that short crop mapping using multi‐temporal Phased Array type L‐band Synthetic Aperture Radar images offered insights into the distributions of crop and paddy fields. Because of the mountainous environment of the study area, combining topographic data of elevation and slope into the classification greatly reduced the confusion between different land use/cover types. Improvement of classification accuracy was evident especially in separating evergreen and deciduous forests from other vegetation types and discriminating urban village and the fallow field classes. 相似文献
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Gal Ariely 《Nations & Nationalism》2012,18(3):461-482
The relationship between globalisation and national identity is puzzling. While some observers have found that globalisation reduces people's identification with their nation, others have reached the opposite conclusion. This article explores this conundrum by examining the relationship between globalisation and people's feelings towards national identity. Using data from the International Social Survey Program National Identity II ( 2003 ) and the World Values Survey ( 2005 ), it analyses these relations across sixty‐three countries. Employing a multilevel approach, it investigates how a country's level of globalisation is related to its public perceptions towards different dimensions of national identity. The results suggest that a country's level of globalisation is not related to national identification or nationalism but it is related negatively to patriotism, the willingness to fight for the country and ethnic conceptions of membership in the nation. An examination of alternative explanations indicates that globalisation has a distinct impact on national identity. 相似文献