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Understanding the Changing Planet is the latest in a long line of reports that makes the case for the relevance of the discipline of geography by invoking big “S” science. My commentary argues that this model of science, with its celebration of large data sets, sophisticated methodological techniques, and various material tools and hardware, is only one model of geography's contribution. Instead, I suggest that the strength of geography is in its pluralism and methodological variety, and in the end that will do more for understanding the changing planet than anything else.  相似文献   

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对流层低层的季风   总被引:11,自引:0,他引:11  
王安宇  尤丽钰 《地理学报》1990,45(3):302-310
文章提出一种对流层低层季风定义的新方法。通过大量的资料分析,作者认为:对流层低层的风可以近似地看作是二部分的线性组合。一部分是非季风的行星风,这部分代表大气对海陆地形的动力强迫的响应;另一部分则是季风,这部分是大气对海陆地形的热力强迫响应。作者用多年平均的年平均风来代表行星风,这样分离出来的季风与经典季风相比有很多优点:1.计算简单;2.物理图象清楚;3.便于划分季风区。  相似文献   

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火星风沙地貌研究进展   总被引:3,自引:2,他引:1  
李继彦  董治宝 《中国沙漠》2016,36(4):951-961
作为最活跃的地貌塑造外营力,风力作用在火星表面塑造了各种各样的地貌形态。对火星风沙活动及风沙地貌的认识是随着观测和探测技术的进步而逐渐明确的。火星沙丘在北极地区连绵成带状分布,在其他地区分布比较零散,且主要与撞击坑、河谷和山谷相伴分布。火星风沙地貌与地球上相应的地貌类型形态相似而规模更大,表明两个星球上塑造风沙地貌的动力系统具有一定的相似性。火星沙丘主要由玄武岩质(北极部分沙丘为石膏质)颗粒堆积而成,沉积物粒度比地球粗,主要是由中沙和粗纱组成。随着获取影像时空分辨率的提高和着陆器在火星近表面的观测,发现火星上部分区域的沙丘和沙波纹比较活跃。同地球一样,火星风沙地貌也可指示火星气候的变化。  相似文献   

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The effort to make the discipline appear relevant and useful raises the danger of allowing applied geography to become yet another “new” geography. Though we must encourage the development of a viable applied geography, we must simultaneously make much greater use of our existing traditions and literature if we are to thrive in the long run as an academic discipline. Without a heritage, we are vulnerable.  相似文献   

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We present a new numerical method to describe the internal dynamics of planetary mantles through the coupling of a dynamic model with the prediction of geoid and surface topography. Our tool is based on the simulation of thermal convection with variable viscosity in a spherical shell with a finite-volume formulation. The grid mesh is based on the 'cubed sphere' technique that divides the shell into six identical blocks. An investigation of various numerical advection schemes is proposed: we opted for a high-resolution, flux-limiter method. Benchmarks of thermal convection are then presented on steady-state tetrahedral and cubic solutions and time-dependent cases with a good agreement with the few recent programs developed to solve this problem.
A dimensionless framework is proposed for the calculation of geoid and topography introducing two dimensionless numbers: such a formulation provides a good basis for the systematic study of the geoid and surface dynamic topography associated to the convection calculations. The evaluation of geoid and surface dynamic topography from the gridded data is performed in the spectral domain. The flow solver is then tested extensively against a precise spectral program, producing response functions for geoid as well as bottom and surface topographies. For a grid mesh of a reasonable size (6 × 64 × 64 × 64) a very good agreement (to within ∼1 per cent) is found up to spherical harmonic degree 15.  相似文献   

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Extraterrestrial geography has become a reality, as we move from Earth's moon to the planets. A broad-scale regional physiography is being established on twenty planets and satellites through remote sensing techniques. Spacecraft images yield most of the information on Solar System landscapes. Topographic measurements are extracted by monoscopic image-processing, stereophotogrammetry, and radar analysis. Invisible parts of the spectrum furnish non-topographic data.  相似文献   

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地球界限概念框架及其研究进展   总被引:1,自引:1,他引:0  
“地球界限(Planetary Boundaries)”是指用于界定“安全运行空间(safe operating space)”的边界值,是Johan Rockstr?m等近年来提出的旨在保障人类生存和发展的重要概念框架。该框架一经提出就引起了广泛关注,一方面质疑者对这一概念框架的科学意义以及评估方法提出批评;另一方面支持者则对其评估方法、研究内容和研究尺度进行了完善和扩展,并取得了重要的成果。为了促进国内学者对该领域的了解和应用,论文在回顾相关文献的基础上,首先介绍了“地球界限”的概念内涵,并将其与中国学者所熟知的环境承载力等概念进行了比较分析;随后总结了该概念框架的争议观点,同时也对其近期的发展状况进行了评述;最后结合中国目前的发展状况,分析了“地球界限”概念框架对中国可持续发展的借鉴意义,并对未来的研究提出了展望,包括① 进一步了解不同地球系统过程的相互作用机制,完善“地球界限”的指标评估体系;② 明确“地球界限”与生态系统服务以及人类福祉三者之间的内在联系;③ 结合“地球界限”的评估结果,加强变革式环境治理的研究。  相似文献   

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Kebun culture’ is a distinctive, emergent form of rural sensibility and social-economic relations in Malaysia. As a contribution to theories of ‘planetary’ or thoroughgoing urbanization, the ethnographic evidence presented in the article illustrate a case of urban annexation of rurality, in which kebun (orchards) are detached from the social organization of rural villages and incorporated into urban-centered Malay society. Kebun, as productive land with non-rice crops, have traditionally been associated with rural kampung (village). In the late twentieth century, thoroughgoing urbanization, driven by both rural-to-urban migration and in situ urbanization of rural kampung, simultaneously produced a social disintegration of Malay kampung and increasingly urban-oriented Malay society. The kebun, which previously was an ancillary part of kampung social ecology has become dissociated from kampung and instead operates as an annex of urban-centered social lives. Kebun are also distinctively individuated rather than communal socio-economic projects. In both reserve lands and kampung areas, urban-based Malays and rural-to-urban return migrants are involved in kebun projects, through which they engage with nostalgic notions of rurality, but without the social entanglements of kampung social relations. At the same time, through kebun projects, urban Malay subjects enter into new social relations, albeit ones marked by commodification.  相似文献   

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Sue Ruddick 《Urban geography》2013,34(8):1113-1130
The anthropological machine is the discursive framework, the dispositif that grounds “Western man” in a sense of civility, secured through a violent division within and between the human and nonhuman: not the after-effect of the civilizing act but its very foundation. This paper explores Agamben’s machine at multiple sites: in its expression in everyday lives of urban citizens, and its legitimation of capitalist urbanization on broader spatial and temporal scales, its “worlding” through planetary urbanization and normalization of climate change. Complicit in capitalist urbanization and climate change, the anthropological machine has acted as a “switch point” since the 1600s. It now frames an emergent response: triage as the inevitable sacrifice of some peoples and parts of the planet to preserve others. If the urban is to become the site of mondialization, confronting the apparent inevitability of triage we must think beyond the either-or of a people or a planet. Thought in relation to the urban, the anthropological machine offers a meeting ground between urban political economy and assemblage urbanism. It enables us to situate the Anthropocene and differentiate the urban. But it also exposes a deep divide between scholars reframing the human beyond “Western man”: between those for whom the more-than-human expresses the dreams of a biophilic city and those for whom the less-than-human is increasingly its living nightmare.  相似文献   

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In this response to Ananya Roy’s paper, I ask: who are the allies of feminist knowledge production about the urban? To explore this question, I specifically ask what feminist scholars may find of use in two books, namely Arrival Cities by Doug Saunders and Implosions/Explosions edited by Neil Brenner, that are representative of two major discourses on the urban, respectively, the “Urban Age” and planetary urbanization, currently favored by policy bodies and (some) academics. Their limited engagement with politics leads me to conclude with a call for a feminist mode of situated knowledge production to engage with (the limits of) urban theory and the urban as a site of praxis.  相似文献   

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Ananya Roy 《Urban geography》2016,37(6):810-823
This essay takes as its provocation a question posed by the feminist philosopher Nancy Fraser: “What’s Critical about Critical Theory?” In urban studies, this question has been usefully reframed by Neil Brenner to consider what is critical about critical urban theory. This essay discusses how the “urban” is currently being conceptualized in various worlds of urban studies and what this might mean for the urban question of the current historical conjuncture. Launched from places on the map that are forms of urban government but that have distinctive agrarian histories and rural presents, the essay foregrounds the undecidability of the urban, be it geographies of urbanization or urban politics. What is at stake is a critical urban theory attentive to historical difference as a fundamental constituting process of global political economy and deconstruction as a methodology of generalization and theorization.  相似文献   

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利用2011年秋冬季榆林大气成分站黑碳浓度、颗粒物质量浓度、大气能见度、地面气象资料,计算边界层高度、气溶胶吸收系数、大气消光系数,导出单次散射反照率,并对其进行分析讨论。结果表明:(1) 榆林秋冬季平均黑碳浓度为2.6 μg·m-3。(2)黑碳占颗粒物质量浓度PM1.0比值为10.6%,黑碳与颗粒物质量浓度PM1.0、PM2.5、PM10相关系数分别为0.91、0.91、0.72。(3)黑碳浓度受边界层高度影响,沙漠风场对黑碳的堆积输送起主导作用。(4) 榆林地区气溶胶吸收系数与大气消光系数比值为16.8%。(5)单次散射反照率平均值为0.72。  相似文献   

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