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Natural Resources Research - The uniaxial compressive strength and static Young’s modulus are among the key design parameters typically used in geotechnical engineering projects. In this... 相似文献
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Ramesh Dhussa 《The Professional geographer》2013,65(2):312-313
In this article, we first replicate and then adapt an existing index of social vulnerability to hazard developed for the United States to a non-U.S. context. We construct indexes for Norwegian municipalities, describe the adjustment process, and compare the replicated and adapted assessments. Our results indicate only a moderate correlation between the replicated and adapted vulnerability indexes and for several municipalities the difference between the indexes is considerable. This demonstrates that context matters and that indexes of vulnerability need to be adapted rather than replicated. To facilitate such adaption processes, we identify three types of accommodation: conceptual, technical, and geographic. 相似文献
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Datta K 《International journal of population geography : IJPG》1995,1(2):183-195
"The issue of return migration has been widely debated in African migration literature in view of strong rural-urban ties and urban growth based largely on in-migration. On the basis of fieldwork in Botswana, it is argued that there are important gender differences in terms of the commitment to rural and urban areas. It has been postulated in past studies that the decision to remain in towns depends in part upon urban tenure and it is argued that home owners are more likely than tenants to be permanent urban dwellers. Again, there are important gender differences and women appear to be more committed to the urban dwelling than men." 相似文献
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Heike Jöns 《The Professional geographer》2017,69(4):670-682
This article examines the role of early female academics at the University of Cambridge in the production and dissemination of knowledge between 1926 and 1955. A statistical comparison of women's use of academic leave of absence with that of their male colleagues reveals that, across disciplines, women were less integrated into (inter)national knowledge networks and thus less visible in their epistemic communities than men because women focused their academic leaves more on research, rarely attended conferences, traveled overseas less often than men, and went more frequently to destinations within Europe than the United States as the new economic hegemon. Biographical case studies of these early female academics demonstrate the importance, variously, of their upper middle-class background, academic excellence, and familial and nonfamilial patronage in developing their careers, overcoming multiple hurdles, and producing intellectual contributions of equal quality to that of their male peers. Conceptually, this article calls for the inclusion of academic travelers from disciplines other than geography into feminist histories of geographical knowledge and argues that rather than stereotyping gender differences, greater comparative research on the experiences of female and male academics is needed to understand the mechanisms of gender inequality within the university. 相似文献
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Michael Gentile 《Urban geography》2013,34(10):1455-1464
ABSTRACTDespite the recent planetary turn that has swept through gentrification research, the theoretical barycentre remains pegged to a few strongholds located in the global north-west. Against this background, this essay offers a provincialized account of three gentrification-like trends – tele-urbanization, Schengtrification and colour-splashing – which are currently taking place in Tbilisi, Riga and Kiev. It is proposed that these processes are supported by an underlying logic that is not pinned to these cities’ specific (“post-communist”) contexts, raising questions about the avowedly universal validity of theories of gentrification stemming from the global northwest, and particularly those developed within the more critical scholarly tradition. 相似文献
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Seed germination was compared among wild, in situ-managed (wild plants let standing in areas cleared for agriculture), and cultivated populations of the columnar cacti Stenocereus pruinosus, Polaskia chichipe, Myrtillocactus schenckii, and Polaskia chende, species representing a gradient from higher to lower management intensity, respectively. We hypothesized that seeds from cultivated populations have higher water requirements to germinate than seeds of other populations, and that such difference is stronger in species more intensely managed. Germination was evaluated under water potential treatments at 0.0, ?0.2, and ?0.4 MPa. Interspecific differences were identified; germination rates markedly decreased in S. pruinosus and P. chichipe as water potential reduced. M. schenckii seeds germinated better at ?0.2 MPa, and seeds of P. chende in all treatments. Seed germination of wild and cultivated populations was similar in all cases and, therefore, at the population level domestication does not appear to have influenced variations in germination of the studied cacti species. However, experiments to test whether germination of seeds from plants with clear signs of domestication differs with seeds from other plants and their differential germination and seedling survival in wild, in situ-managed and cultivated environments could help to precise the influence of domestication on these plants. 相似文献
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Parisa Gholami Zadeh Mohammad Hossein Adabi Mohammad Reza Ghassemi Abbas Sadeghi Safar Ali Eshraghi 《Basin Research》2020,32(6):1626-1652
Mélanges are formed by sedimentary, tectonic and diapiric processes and are generally found in collisional belts. The Zagros Orogeny provides an intriguing geological laboratory for the study of mélange-forming processes during the progressive tectonic evolution of the Neotethys Ocean. Different types of tectonic and sedimentary mélanges occur in specific structural positions within the Zagros orogenic belt in the Neyriz Region (Iran). Based on their block-in-matrix fabrics, and tectonostratigraphic positions, we differentiated 14 different mélange types, which mark different episodes of the tectonic evolution of the Neyriz Region from the Cretaceous subduction to the Miocene collision. The Cretaceous subduction stage is recorded by volcanic-sedimentary mélanges (Mv). Sedimentary mélanges characterized by megabreccia from the Cretaceous limestone (Ms1) and Eocene polymictic megabreccia (Ms2) represent epi-nappe mélanges formed during the Palaeocene–Eocene in wedge-top basins. The ophiolite emplacement in the Oligocene resulted in local extensional tectonics in the upper part of the ophiolitic nappe, and deposition of a polymictic megabreccia (Ms3, Ms4). As the final production of the Neotethys Ocean closure and the Eurasian-Arabian collision, the sedimentary mélanges characterized by different types of chaotic rock units (Ms5, Ms6, Ms7 and Ms8 facies) were developed in front of the Cretaceous–Eocene nappes due to growth of the orogenic wedge in the Miocene. Our findings indicate that the recognition and distinction of different types of mélange may provide additional constraints for a better understanding of the tectono-sedimentary evolution of the Neotethyan region. 相似文献
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《Norsk geografisk tidsskrift. Norwegian journal of geography》2012,66(2):83-101
Protected area management in Norway is undergoing institutional changes with the implementation of management models aimed at increased public participation. At the same time tourism enterprises are increasing in number within the protected areas. Greater levels of interaction with stakeholders place new demands on lead institutions in terms of communication, transparency, involvement, and power sharing. A governance perspective was used to examine some facets of the interaction between a local council managing a national park in Norway and tourism companies using the park for their operations. The main objective was to assess how the tourism sector perceives the cooperation and interface with the management institution. Semi-structured interviews were used, together with a framework of United Nations Development Programme principles of good governance: legitimacy and voice, direction, performance, accountability, and fairness. The results showed rather negative evaluations by the tourism sector, and operators expressed views, implying that the current management model fails to achieve most of the principles of good governance. Although based on a one-sided view by one group of stakeholders, the study suggests that lack of access to important processes and decisions, perceived bias towards traditional conservation, neglect of cultural heritage, and undue restrictions on access could have serious implications for developing an effective management model. 相似文献
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Robert M Vanderbeck 《Area》2008,40(3):393-400
A small but growing number of voices have begun to raise questions about the current direction of children's geographies as a subfield and its status within the wider discipline. This article intervenes in these emerging discussions to examine the status of debate itself within children's geographies. I argue that children's geographies over the past decade has operated primarily in a consensus-based mode, with a number of potential tensions and differences between practitioners masked as a result. I develop the example of notions of children's competent social agency, a core theoretical assumption that is rarely interrogated in much depth. In closing, I pose questions regarding several contemporary political issues concerning children's agency about which geographers have had surprisingly little to say. I suggest that explicitly addressing some of these vexing issues would contribute to a richer state of debate within children's geographies. 相似文献
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Fire has been historically infrequent in the Mojave Desert, and its increased prevalence caused by the invasion of non-native annual grasses is a major concern for land managers there. The most dramatic changes have occurred in middle elevation shrublands dominated by creosotebush (Larrea tridentata), Joshua tree (Yucca brevifolia), and/or blackbrush (Coleogyne ramossissima), where most of the fires occurred between 1980 and 2004. This zone is more susceptible than other areas of the Mojave Desert to increased fire size following years of high rainfall. Increases in fire size are likely related to the flush of non-native annual grasses, Bromus rubens in particular, that produces continuous fuelbeds following years of high rainfall. This dynamic also has occurred to some degree at lower elevations, but the background cover of native perennial fuels there is already very low, muting the effects of the ephemeral fuels. At elevations above the middle elevation shrublands, fire size does not vary with rainfall, indicating that native woody fuels dictate fire regimes. These results suggest that an invasive plant/fire regime cycle is currently establishing in the middle and possibly the low elevation shrublands of the Mojave Desert, but not at higher elevations. 相似文献
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Climate change and human activities have profoundly altered ecosystem services in the Yellow River Basin(YRB) since the Grain for Green project was implemented, but have not been accurately revealed on a year-by-year scale. This study combined the InVEST model to reveal the year-by-year changes in the water-related ecosystem services(WRESs)in YRB during 1990–2020, including water yield, soil conservation and water purification services. The trade-off/synergy of WRESs and impacts of land manageme... 相似文献
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We examined change in areal extent of mountain meadows and fields of deciduous shrubs and conifer saplings in the central western Cascade Range of Oregon, based on analysis of aerial photographs taken in 1946 and 2000. These nonforest vegetation patches are distinctive habitats in dominantly forested landscapes, such as the Cascades, and change in extent of these habitats is of interest to scientists and land managers. We mapped and dated even-aged forest stands of probable postfire origin around the nonforest patches, using tree-ring analysis and interpretation of aerial photographs. We used these and archival data to interpret possible influences of past wildfire and sheep grazing on the extent of nonforest patches. The total area of nonforest vegetation patches decreased from 5.5 percent of the study area in 1946 to 2.5 percent in 2000. Significantly more cases of contracted patches were observed for mesic and xeric meadows which have adjacent forest established after wildfire in the approximately 150 years preceding 1946. A higher proportion of mesic (47 percent, n = 47) than xeric (17 percent, n= 115) meadows contracted between 1946 and 2000. Broad-leaved shrub fields were unchanged, probably because of topo-edaphic controls, dense cover of shrubs, and snow effects; but all fields of conifer saplings underwent succession to forest. We observed no strong influences of sheep grazing on the extent of meadows. 相似文献
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Karst depressions are common negative topographic landforms formed by the intense dissolution of soluble rocks and are widely developed in Guizhou province. In this work, an inventory of karst depressions in Guizhou was established, and a total of approximately 256,400 karst depressions were extracted and found to be spatially clustered based on multidistance spatial cluster analysis with Ripley’s K function. The kernel density(KD) can transform the position data of the depressions into a smooth... 相似文献
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Monitoring and simulation of water, heat,and CO2 fluxes in terrestrial ecosystems based on the APEIS-FLUX system 总被引：2，自引：0，他引：2
WATANABEMasataka WANGQinxue HAYASHISeiji MURAKAMIShogo LIUJiyuan OUYANGZhu LIYan LIYingnian WANGKelin 《地理学报(英文版)》2005,15(2):131-141
1IntroductionInJune1992,theworldsummitorganizedbytheUnitedNations,withparticipantsincludingnationalleadersfromaroundtheworld,concludedwithAgenda21(UnitedNations,1992),theRioDeclarationonEnvironmentandDevelopment,inRiodeJaneiro.Thedeclarationpromptedcountr… 相似文献
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In this article we argue that planning theory and practice should engage more with the normative political vision of Gilles Deleuze and Félix Guattari. They reject the transcendent authority of the State and arguably by extension, planning. As planners we should be concerned: need we reconceptualize, or abandon the planning project? We outline their vision, highlighting key concepts including lines of flight, revolution, the new land, and immanent organization, and use two cases from the United States and Mexico, the Food Commons and Center for Integral Farmer Development in the Mixteca, to show that planning in accordance with Deleuze and Guattari may indeed be possible. We end with questions: is what we describe planning? And what is planning – or what should it be? 相似文献
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Laura Beth Bugg 《The Australian geographer》2012,43(3):273-289
This article examines land-use development applications for minority religious facilities in two local government areas on the rural–urban fringe of metropolitan Sydney, Australia. Using critical discourse analysis and underpinned by Lefebvre's (1991) conceptual triad of space, the work interrogates the way in which place identity is generated and codified both by land-use planners and local residents through spatial representation. This representation is revealed in discourses around the compatibility of minority religious facilities for particular zones, lack of a sufficient minority population and social disruption. These discourses reveal a construction of peri-urban space that is aligned with particular elite Anglo-Australian activities (horse riding and gentleman farms) and land uses (rural residential, small-scale agriculture and the ‘bush-church’). These case studies illustrate the potential for the creation of exclusionary, abstract space by urban planners but also the ways in which local residents use discoursive strategies to ensure the stability of their position as elites in rapidly changing spatial situations. 相似文献
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ZHANG Mingyu ZHANG Zhengyong LIU Lin ZHANG Xueying KANG Ziwei CHEN Hongjin GAO Yu WANG Tongxia YU Fengchen 《地理学报(英文版)》2023,(10):2031-2051
The mass elevation effect(MEE) is a thermal effect, in which heating produced by long wave radiation on a mountain surface generates atmospheric uplift, which has a profound impact on the hydrothermal conditions and natural geographical processes in mountainous areas. Based on multi-source remote sensing data and field observations, a spatial downscaling inversion of temperature in the Tianshan Mountains in China was conducted, and the MEE was estimated and a spatio-temporal analysis was conduct... 相似文献