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1.
The aim of this paper is to develop a methodology for identifying various dimensions of the spatial configuration of urban systems in Iran from an interaction perspective. Through the provision of empirical evidence of different types of flows of people including air passenger flows, passenger flows by bus and car, this paper compares the resulting spatial constellations of these flows through the innovative use of indices to systematically describe and measure five dimensions of an urban system’s spatial configuration that include: (1) centrality and dominance of vertices, (2) network cohesion, (3) network strength, (4) network symmetry, and (5) communities and levels. The findings show that although the spatial configurations of different flows are not the same, all were characterized by having a significant distance within a polycentric urban system due to the primacy of the Tehran metropolis. In regard to passenger flows by car and bus, it was found that for various functional regions, there was a balanced distribution of centrality and urban hierarchy evident in Iran. By contrast, air passenger flows were not able to determine centrality within a national urban hierarchy because of the limited distribution of centers for air travel in Iran at higher levels of spatial organization. 相似文献
2.
Nicholas Blomley 《Geoforum》2005,36(3):281-296
Legal spaces are said to be a crucial materialization of law, serving to communicate legal meaning and, in so doing, helping to produce a liberal-legal consciousness. Given its centrality to legal ordering and liberal ideology, the spatial manifestation of the public-private divide, especially when related to property, would appear to be particularly important in this regard. Public and private are assumed to be both mutually exclusive and exhaustive. Drawing upon empirical research conducted in a neighbourhood in Vancouver, Canada, I argue that spatial and legal categories such as public and private may be more fluid than one might suppose. While the public/private divide is clearly powerful, and informs much policy and governmental action, it is not necessarily the case that it has the purchase on everyday life that some scholars have suggested. People may live in more complicated and overlapping worlds when it comes to supposedly determinate categories such as property. 相似文献
3.
4.
Community geography emphasizes the centrality of community engagement to socially transformative research. This introduction to a special issue of GeoJournal on community geography outlines how this growing subfield provides a model for collaborative action with the crises of our time, from white supremacy through climate change. As the co-editors of this special issue, we summarize the contents of these 14 articles, grouping them by the shared themes of power, institutional partnerships, pedagogy, and methods.
相似文献5.
Peripherality in the global container shipping network: the case of the Southern African container port system 总被引：1，自引：0，他引：1
Regional trade co-operation, economic growth and greater political stability have enabled increased container throughput and container port capacity development. Earlier academic work has indicated that the functional position of this port region in the global maritime network might be shifting from a remote region in the periphery of the network to a more intermediate position. This paper aims to analyze the changing level of peripherality and remoteness of the Southern African container port system as part of the global container shipping network. The central hypothesis is that Southern Africa has moved from a remote shipping region to a more central shipping region in the global network. The methodology consists of the calculation of network measures for Southern African ports. The changing geographical distribution of flows among the main container ports in South Africa, Namibia, Mozambique, Mauritius and Madagascar will also be explored in terms of their respective shipping services, port calling patterns, market structure (in terms of the number of active carriers) and the up-scaling of vessel and port capacity. The overall result is a mapped port hierarchical structure with a clear indication of the shifted maritime centrality of Southern African ports from 1996 to the present decade. 相似文献
6.
Ray Hibbins 《Geoforum》2005,36(2):167-180
This paper reports on a study of the effects of migration on constructions of masculinities among Chinese skilled male migrants to Australia over the past 50 years. Data were collected in in-depth, semi-structured interviews of a sample of 40 Chinese male migrants in Brisbane city. The respondents came from a variety of countries of origin and varied in marital status, sexuality, age and previous migration experiences as well as duration of settlement in Australia. Because of an immigration policy based on a points system for measuring skill potential among migrants, these informants were of middle to upper-middle socio-economic status. Core ideas which emerged from the study included: Chineseness; insularity; the centrality of family, kin and friendship networks; Chinese males in the workplace; the division of labour in the household; employment and the fears of unemployment. These Chinese skilled male migrants displayed qualities of hegemonic masculinity in their households where traditional Chinese division of labour persisted. The markers of masculinity included: centrality of work and education; being a successful provider and protector; the accumulation of wealth and power. Unlike local hegemonic variants of masculinity these males placed little emphasis on sport, sexual prowess and performance and alcohol consumption. There were no ambitions among this sample of males to model local variants of masculinities, however gay males in the sample while experiencing marginalisation, racism and homophobic behaviour at the hands of local hegemonically masculine males, were more like the local dominant males in terms of an emphasis on sexual performance and preferences for well-muscled and fit bodies. Gay males in the Chinese sample found it necessary to restrict their social circles and physical locales. This Australian study has demonstrated the importance of the cultural sensitivity of concepts in doing comparative studies, and of considering sexuality as a dimension of identity in migration research that seems to assume a heteronormativity in its samples. 相似文献
7.
Oren Yiftachel 《GeoJournal》2001,53(3):283-293
This paper uses a critical political-geographical perspective to account for the high centrality of power found in Israel. It suggests that the concentration of power have not been solely caused by national solidarity and integration or by metropolitan development, as commonly explained, but also by the territorial `fracturing' of the main social and ethnic groups in Israel/Palestine. This has prevented the emergence of effective pressure for regional devolution. Israel's character as a settler and settling state, and its central project of Judaizing contested territories, enabled the Israeli `ethnocracy' and its (mainly Ashkenazi and secular) elites to create a political geography of `fractured ethnic and social regions'. Dispersing minorities and legitimizing segregation and inequality, all in the name of the `national interest', achieved this. The Israeli political landscape is therefore organized as `fractured regions', each representing a distinct and interconnected, yet geographically dispersed, set of localities, and resembling a `chain of beads'. The logic of dispersal and segregation, in turn, has also influenced patterns of development and residential separation within Israel's main urban areas. Thus, ethnic and social fragmentation and conflict, and not a putative process of national or metropolitan integration, can explain much of Israel's highly centralized power structure. 相似文献
8.
Karim Saheb Ettabaa Manel Ben Salem Med Salim Bouhlel 《Arabian Journal of Geosciences》2017,10(18):412
Segmentation-based anomaly detectors proceeds to the clustering of the hyperspectral image as a first step. However, most of the well-known clustering methods cluster anomalous pixels as a part of the background. This paper presents a new hyperspectral image clustering approach based on the betweenness centrality measure. The proposed approach starts by the construction of an adaptive spatial and spectral neighborhood for each pixel. This neighborhood is based on the selection of the nearest spectral and spatial neighbors in multiple windows around each pixel to allow well-suited representation of the image features. In the next step, this neighborhood is clustered based on the edge betweenness measure algorithm that splits the image into regions sharing similar features. This approach (1) allows the reduction of intercluster relationship, (2) favors intracluster relations, and (3) preserves small clusters that can hold anomalous pixels. Experimental results show that the proposed approach is efficient for clustering and overcomes the state of the art approaches. 相似文献
9.
As containerization enters its peak growth years, its potential future developments over maritime and inland freight transport
systems are being questioned. A series of issues can either further accelerate the adoption of containerization worldwide
or, alternatively, could impose an upper limit to the extraordinary contribution that containers have implied for logistics
systems and global commodity chains. These mainly include macro-economic, technical/operational and governance factors. Future
containerization will be largely determined by interactions within and between four domains ranging from a functional to a
spatial perspective. The logistical domain involves the functional organization of transport chains and their integration
in supply chains. The transport domain involves the operation of transport services and intermodal operations. The infrastructural
domain involves the provision and management of basic infrastructure for both links and nodes in the transport system. The
locational domain relates to the geographical location of nodes and sites in the economic space and forms a basic element
for their intrinsic accessibility in terms of centrality or intermediacy. It is underlined that the future of containerization
will dominantly be shaped by inland transport systems. 相似文献
10.
This paper is an empirical attempt to measure the relative concentration of port–city functions in the context of globalisation.
It reviews a number of urban and port issues regarding their complementary and contradictory aspects about the evolution of
port cities. The main purpose is to verify how port function is more or less important to local economies, compared to other
functions, through a temporal and global approach. Based on a matrix of port–city centrality and intermediacy, the main indicators
available for international comparison are urban population and container throughput. An analysis of 653 places between 1970
and 2005 period is provided, using the relative concentration index (RCI) proposed by Vallega. The appropriate geographical
scale to measure the relative evolution of port cities at a global level is discussed. Results tend to question previous models
which consider functional and spatial separation between the city and its port as an ineluctable process. The port–city evolution
appears to be gradual rather than linear or chaotic, and in many cases largely influenced by regional factors and local strategies. 相似文献
11.
传统水系连通方案编制主要以水系结构为主导,忽略了连通后对水系功能的影响,本文在进行城市水系布局时,将水系连通形状和连通功能两部分纳为一体来制定水系连通方案。基于中心性评价方法,提出河段重要性计算方法来定量刻画河段重要性;借助隶属度函数建立连通功能及其表征参数的函数关系,据此量化水系连通功能效果;以河网连通功能达标率和水系连通性满足度为优选目标,建立结构-功能耦合下的水系连通方案两阶段优化模型,优选最佳闸门联合调度方案。以清潩河许昌段为实例,优化原河网及不同水系连通情景的连通性。研究表明:经过优化后,原河网清潩河水系连通性总体较好,但护城河附近和饮马河的连通性较差;连通护城河和清泥河、连通饮马河和小洪河能极大地提升护城河附近和饮马河的水系连通性。 相似文献
12.
Antonio Gramsci’s writings provide a valuable conceptual and political sensibility for critical approaches to nature. In this editorial introduction to a theme issue on Gramscian Political Ecologies we establish the broad contours to such an approach, stressing Gramsci’s integral marxism and commitment to a transformative politics relevant to the contemporary moment. Subsequently, we provide an introduction to existing political ecological research inspired by Gramsci’s wide-ranging writings. In order to stimulate future research, we question Gramsci’s reflections on ’nature’ in order to examine the embyonic possibilities and limitations therein. Gramsci, we suggest, provides stimulating commentary on the differentiated unity of nature and society: in part, this anticipates recent arguments on this subject. Similarly, we reflect on how Gramsci’s conceptualization of hegemony relates to core issues within political ecology. Given the centrality of ’environmental issues’ in the contemporary moment, it is necessary to consider how social groups enrol natures and environments (both material and symbolic) in their struggles for hegemony. We conclude the editorial by introducing the articles included in the theme issue. 相似文献
13.
Ecological restoration, cultural preferences and the negotiation of ‘nativeness’ in Australia 总被引：1，自引：0，他引：1
The paper addresses cultural assumptions about ‘nativeness’ and ‘belonging’ to place as they are implicated in notions of ‘ecological restoration’. Given the centrality of complex notions of ‘indigeneity’ to the issue of what ecological ‘restoration’ means in Australia, this is a rich area for cultural and historical analysis. Case materials illustrate the negotiated and ambiguous nature of Australian ideas about what ‘belongs’ ecologically and culturally across the broad continent of this relatively young post-Settler nation. We seek to foreground these issues through consideration of what ‘restoring’ nature might mean in the context of debates about native plants, the re-introduction of an iconic species of ground dwelling bird, the removal of cane toads that are demonised as highly ‘alien’, and the multiple ways in which the dingo is regarded ambiguously as both native and a ‘pest’ that needs to be controlled and culled. By showing how ‘restoration’ can be understood and mobilised in a variety of ways – in terms of the ‘re-naturing’, ‘re-valuing’ and/or ‘repatriating’ of indigenous species, as well as impassioned rejection of ‘exotics’ – we emphasise the importance of social science for building a well-grounded sense of how environmental management priorities and approaches are informed by a wider set of cultural assumptions. 相似文献
14.
Janaina Bezzerra Silva Mariana A. Giannotti Ana Paula C. Larocca José Alberto Quintanilha 《GeoJournal》2017,82(2):293-310
Spatial data have been used for the environmental monitoring of the consequences of accidents that involve the transportation of hazardous chemical products. This spatial data infrastructure (SDI), which was created for the sharing and use of spatial data, is limited by the absence of policies to support its establishment. The main objective of this study was to explore the use of social network analysis (SNA) as a tool to identify spatial data sharing between organizations involved in the management of accidents related to road transport of hazardous materials (RTHM). In addition, to discuss the existing policies and institutional agreements, and to initiate a conceptual SDI framework for RTHM sector. In this context, the institutions that are involved with RTHM were identified and information concerning their interest in the use and sharing of spatial data via a SDI was collected through interviews and consolidated. The interviews were at 39 institutions with representative employees. The interview data were tabulated and entered into the UCINET software (2000 version) to calculate metrics of centrality. From the SNA, the flow of data among the participating institutions was identified through the visual representation of the spatial data sharing and use networks. Subsequently, the existing institutional agreements for spatial data sharing were analyzed and discussed. The compiled results enabled the proposal of a conceptual SDI framework to support the management of disasters involving RTHM, based on the application of SNA theory, and the development of a methodology that supports the analysis of interactions among the various actors of an SDI. The purpose is to facilitate the formulation of policies for the sharing of spatial data for decision-making and preventive disaster management. The results indicate that the 39 institutions share spatial data, but this sharing is not always predetermined by formal agreements. Furthermore, there is a strong demand, by the institutions involved in the management of RTHM accidents, regarding legal mechanisms governing the sharing of data for the purpose of producing maps that help to describe actions of preparedness, prevention, management and immediate relief involving RTHM incidents. Finally, it was possible to propose a conceptual framework with data that is considered essential for creating an SDI for RTHM. 相似文献
15.
The notion of community has been central to the political project of renewal of New Labour in the UK. The paper explores how
the discourses of community are framed within New Labour and discusses these in the light of the results from research which
focuses on how people within urban deprived areas construct their community. It draws upon the results of one part of a larger
research project (the ‘Well London’ programme) which aimed to capture the views of residents from 20 disadvantaged neighbourhoods
throughout London using an innovative qualitative method known as the ‘World Café’. Our results show the centrality of young
people to the development of cohesive communities, the importance of building informal relationships between residents alongside
encouraging greater participation to policy making, and the need to see these places as fragile and temporary locations but
with considerable social strengths. Government policies are only partially addressing these issues. They pay greater attention
to formally encouraging citizens to become more involved in policy making, largely ignore the contribution young people could
make to the community cohesion agenda, and weakly define the shared norms and values that are crucial in building cohesive
communities. Thus, the conclusion is that whilst an emphasis of the government on ‘community’ is to be welcome, more needs
to be done in terms of considering the ‘voices’ of the community as well as enabling communities to determine and act upon
their priorities. 相似文献
16.
We simulate a large-scale flooding in the province of South-Holland in the economic centre of the Netherlands. In traditional research, damage due to flooding is computed with a unit loss method coupling land use information to depth-damage functions. Normally only direct costs are incorporated as an estimate of damage to infrastructure, property and business disruption. We extend this damage concept with the indirect economic effects on the rest of the regional and national economy on basis of a bi-regional input output table.We broaden this damage estimation to the concept of vulnerability. Vulnerability is defined as a function of dependence, redundancy and susceptibility. Susceptibility is the probability and extent of flooding. Dependency is the degree to which an activity relates to other economic activities in the rest of the country. Input–output multipliers form representations of this dependency. Redundancy is the ability of an economic activity to respond to a disaster by deferring, using substitutes or relocating. We measure redundancy as the degree of centrality of an economic activity in a network. The more central an activity is, the less it encounters possibilities to transfer production and the more vulnerable it is for flooding. Vulnerability of economic activities is then visualized in a GIS. Kernel density estimation is applied to generalize point information on inundated firms to sectoral information in space. We apply spatial interpolation techniques for the whole of the province of South-Holland. Combining information of sectoral data on dependency and redundancy, we are able to create maps of economic hotspots. Our simulation of a flood in the centre of Holland reveals the vulnerability of a densely populated delta. 相似文献
17.
Manuel Valera Zhengyang Guo Priscilla Kelly Sean Matz Vito Adrian Cantu Allon G. Percus Jeffrey D. Hyman Gowri Srinivasan Hari S. Viswanathan 《Computational Geosciences》2018,22(3):695-710
Structural and topological information play a key role in modeling flow and transport through fractured rock in the subsurface. Discrete fracture network (DFN) computational suites such as dfnWorks (Hyman et al. Comput. Geosci. 84, 10–19 2015) are designed to simulate flow and transport in such porous media. Flow and transport calculations reveal that a small backbone of fractures exists, where most flow and transport occurs. Restricting the flowing fracture network to this backbone provides a significant reduction in the network’s effective size. However, the particle-tracking simulations needed to determine this reduction are computationally intensive. Such methods may be impractical for large systems or for robust uncertainty quantification of fracture networks, where thousands of forward simulations are needed to bound system behavior. In this paper, we develop an alternative network reduction approach to characterizing transport in DFNs, by combining graph theoretical and machine learning methods. We consider a graph representation where nodes signify fractures and edges denote their intersections. Using random forest and support vector machines, we rapidly identify a subnetwork that captures the flow patterns of the full DFN, based primarily on node centrality features in the graph. Our supervised learning techniques train on particle-tracking backbone paths found by dfnWorks, but run in negligible time compared to those simulations. We find that our predictions can reduce the network to approximately 20% of its original size, while still generating breakthrough curves consistent with those of the original network. 相似文献
18.
Kirsten Valentine Cadieux 《GeoJournal》2011,76(4):341-363
This paper explores different ways that the category of nature is used in addressing landscape changes associated with exurbia
and exurbanization. Nature is an important category in the practices and representations that residents and planners use to
construct and maintain exurban landscapes. However, common ways of mobilizing nature in exurban planning discourses often
obstruct better discussion, rather than facilitate it. Invoking nature can make planning processes more difficult by providing a means
for naturalizing planning decisions and also by exacerbating struggles over whose nature will be managed in what ways. More
explicitly framing what is meant by nature in exurban planning may improve discussion of landscape problems associated with
sprawl. The goal of this paper is to contribute to creating a framework for more actively contextualizing how “nature” is
used in discourses relating to exurbanization. I suggest that such a framework would need to consider—and make explicit—themes
such as the four that I discuss in this paper: (1) the centrality of the production of nature to exurban landscapes; (2) multiple
meanings of nature that are often confused; (3) ways that normative statements about nature tend to be unquestioned in exurban
planning; and (4) the simultaneous difficulty and usefulness of critiquing and “denaturalizing” both material and discursive
nature. Explicit conversations about the role and representation of nature within residents’ and managers’ land-use practices
and ideologies could create opportunities for dialogue between residents, planners, and academics about the valuation of and
preferences for constructing particular landscapes, especially in addressing problematic aspects of the phenomena of “amenity
migration” and “sprawl.” 相似文献
19.
Guboglo M. N. 《GeoJournal》1980,4(1):53-58
International unity is becoming ever stronger in this country owing to an increasing similarity in the development of the cultural environment. This comprises the provision of all the country's republics with a sufficient number of schools, theatres, and other institutions and cultural information media in accordance with the needs of the population. An important part is played by the rise in ‘the general educational level, as well as the level of professional qualifications and skills. Among all the Soviet nations and nationalities, this rise being more rapid among formerly backward peoples. Prominent among the factors of internationalization is the progressive development of the nationalities’ cultural resources, while professional culture is being increasingly brought within the reach of the masses.The implementation of the nationalities policy promotes the all-round development of all Soviet nations and nationalities, their drawing together, the upsurge of the individual capabilities of every Soviet citizen. 相似文献
20.
Chronological analyses of correlations between certain global repeating events (mass extinctions of marine organisms, meteorite impacts, and flashes in the frequency of geomagnetic reversals) during the Phanerozoic Eon and the motion of the solar system in the Galaxy are presented for five rotationally symmetrical models for the regular Galactic gravitational field. Thirteen of sixteen mass-extinction events can be described by a repetition interval of 183±3 million years. This is in agreement with the anomalistic period (interval between two subsequent passages of the Sun through the apocenter of its Galactic orbit) in the model of Allen and Martos. The positions of the minima and maxima in Gaussian functions approximating the frequency distribution for geomagnetic reversals also agree with the times of passage of the Sun through the apocenter and pericenter, respectively, of its Galactic orbit in this model. The maximum in the distribution of the deviations of the dates of mass extinctions from the nearest dates of impacts of large, crater-forming bodies is close to zero, providing evidence that many such events are correlated. As a rule, extinctions follow impact events. The impacts of large bodies have occurred most often when the solar system passes through the Galactic plane, while mass extinctions occur more often at some distance from the Galactic plane (about 40 pc). As a rule, intervals of increases in the frequency of geomagnetic reversals coincide with dates of impacts of large bodies. At the same time, these intervals do not show a clear correlation with the dates of mass extinctions. The intensity of mass extinctions, like the energy released by impacts, is consistently higher in periods when the Sun is moving from the apocenter toward the pericenter of its orbit, than when it is moving from the pericenter toward the apocenter. Thus, there is evidence for a variety of relationships between repeating global events in the Phanerozoic and the motion of the Sun in the Galaxy. Long-period variations in the frequency of geomagnetic reversals are correlated with the orbital motion of the Sun, and increases in the frequency of geomagnetic reversals are correlated with impacts. Mass extinctions are correlated with the impacts of large bodies, whose motions may have been perturbed by clouds of interstellar material concentrated toward the Galactic plane and by the shock front associated with the Perseus spiral arm, through which the solar system passes. The velocity of the Sun relative to the spiral pattern is estimated. 相似文献