Zipf’s law for all the natural cities around the world

Two fundamental issues surrounding research on Zipf’s law regarding city sizes are whether and why this law holds. This paper does not deal with the latter issue with respect to why, and instead investigates whether Zipf’s law holds in a global setting, thus involving all cities around the world. Unlike previous studies, which have mainly relied on conventional census data such as populations and census-bureau-imposed definitions of cities, we adopt naturally (in terms of data speak for itself) delineated cities, or natural cities, to be more precise, in order to examine Zipf’s law. We find that Zipf’s law holds remarkably well for all natural cities at the global level, and it remains almost valid at the continental level except for Africa at certain time instants. We further examine the law at the country level, and note that Zipf’s law is violated from country to country or from time to time. This violation is mainly due to our limitations; we are limited to individual countries, or to a static view on city-size distributions. The central argument of this paper is that Zipf’s law is universal, and we therefore must use the correct scope in order to observe it. We further find Zipf’s law applied to city numbers; the number of cities in the largest country is twice as many as that in the second largest country, three times as many as that in the third largest country, and so on. These findings have profound implications for big data and the science of cities.     

The geographical aspects of the substantiation for the development of the “Greater Irkutsk” agglomeration

An analysis is made of the geographical circumstances and factors of formation of a large urban agglomeration to unite the cities of Irkutsk, Angarsk and Shelekhov in the south of the Irkutsk region. The principles of delineating the agglomeration are formulated, which are used to single out different variants of the urban “Greater Irkutsk” agglomeration. A comparison is made of the characteristics of the agglomeration obtained in the different variants.     

Changes in the age of New Zealand farmers: Problems for the future?

Earlier research shows that between 1971 and 1981, the number of farmers in New Zealand increased and their average age decreased, whereas between 1981 and 1991, the opposite trend occurred. This article addresses the issue of change in the average age of farmers since 1991 using recent census data. It reviews the difficulties in obtaining good data and describes the adjustments need to be made to obtain a consistent data series from 1971 to 2006. The long-term trend for increasing age of farmers and farm workers continues. This demographic aspect of farm structural change is then discussed in terms of the sustainability of farming by reference to productivity and potential problems with succession.     

A ‘demonstrator’ for the National Geosciences Data Index

Abstract

A survey of users of geosciences data in Great Britain, carried out as part of the Databank Pilot Study jointly supported by the Department of the Environment and the British Geological Survey, indicated a priority requirement for a central geosciences data index. The consultations suggested that the system should contain information about the sources, accessibility and nature of data held in both centralized and widely-distributed collections. To illustrate to users how such a system would appear in its final implementation, and in order to refine the system's specification, the British Geological Survey developed, on an Intergraph Interpro 32 Workstation, a working demonstration of a ‘user-friendly’, interactive graphical index, capable of satisfying the requirements of a wide range of users of geosciences data. This paper describes the development of the ‘demonstrator’, its structure, content and implementation, and the benefits of adopting such an approach.     

An analytic solution to the alibi query in the space–time prisms model for moving object data

Moving objects produce trajectories, which are stored in databases by means of finite samples of time-stamped locations. When speed limitations in these sample points are also known, space–time prisms (also called beads) (Pfoser and Jensen 1999 Pfoser, D. and Jensen, C.S. 1999. “Capturing the uncertainty of moving-object representations”. In Advances in spatial databases (SSD’99), Hong Kong, China, July 20–23, 1999, Vol. 1651, 111–132. Lecture notes in Computer Science.  [Google Scholar], Egenhofer 2003 Egenhofer, M. 2003. “Approximation of geopatial lifelines”. In SpadaGIS, workshop on spatial data and geographic information systsems, 4SpaDaGIS–Workshop on Spatial Data and Geographic Information Systems, Milano, Italy, March 2003. University of Genova.  [Google Scholar], Miller 2005 Miller, H. 2005. A measurement theory for time geography. Geographical Analysis, 37(1): 17–45. [Crossref], [Web of Science ®] , [Google Scholar]) can be used to model the uncertainty about an object's location in between sample points. In this setting, a query of particular interest that has been studied in the literature of geographic information systems (GIS) is the alibi query. This boolean query asks whether two moving objects could have physically met. This adds up to deciding whether the chains of space–time prisms (also called necklaces of beads) of these objects intersect. This problem can be reduced to deciding whether two space–time prisms intersect.

The alibi query can be seen as a constraint database query. In the constraint database model, spatial and spatiotemporal data are stored by boolean combinations of polynomial equalities and inequalities over the real numbers. The relational calculus augmented with polynomial constraints is the standard first-order query language for constraint databases and the alibi query can be expressed in it. The evaluation of the alibi query in the constraint database model relies on the elimination of a block of three exªistential quantifiers. Implementations of general purpose elimination algorithms, such as those provided by QEPCAD, Redlog, and Mathematica, are, for practical purposes, too slow in answering the alibi query for two specific space–time prisms. These software packages completely fail to answer the alibi query in the parametric case (i.e., when it is formulated in terms of parameters representing the sample points and speed constraints).

The main contribution of this article is an analytical solution to the parametric alibi query, which can be used to answer the alibi query on two specific space–time prisms in constant time (a matter of milliseconds in our implementation). It solves the alibi query for chains of space–time prisms in time proportional to the sum of the lengths of the chains. To back this claim up, we implemented our method in Mathematica alongside the traditional quantifier elimination method. The solutions we propose are based on the geometric argumentation and they illustrate the fact that some practical problems require creative solutions, where at least in theory, existing systems could provide a solution.     

‘Big data’ for pedestrian volume: Exploring the use of Google Street View images for pedestrian counts

New sources of data such as ‘big data’ and computational analytics have stimulated innovative pedestrian oriented research. Current studies, however, are still limited and subjective with regard to the use of Google Street View and other online sources for environment audits or pedestrian counts because of the manual information extraction and compilation, especially for large areas. This study aims to provide future research an alternative method to conduct large scale data collection more consistently and objectively on pedestrian counts and possibly for environment audits and stimulate discussion of the use of ‘big data’ and recent computational advances for planning and design. We explore and report information needed to automatically download and assemble Google Street View images, as well as other image parameters for a wide range of analysis and visualization, and explore extracting pedestrian count data based on these images using machine vision and learning technology. The reliability tests results based on pedestrian information collected from over 200 street segments in Buffalo, NY, Washington, D.C., and Boston, MA respectively suggested that the image detection method used in this study are capable of determining the presence of pedestrian with a reasonable level of accuracy. The limitation and potential improvement of the proposed method is also discussed.     

Variations and trends of the freezing and thaw- ing index along the Qinghai-Xizang Railway for 1966?2004

Annual freezing and thawing index of 7 meteorological stations along the Qing-hai-Xizang Railway were calculated based on daily maximum and minimum temperature records for 1966?2004. Trends of annual freezing and thawing index were analyzed using the Mann-Kendall test and a simple linear regression method. The results show that: 1) The mean annual freezing indices range from 95 to 2300℃·d and the mean annual thawing indi-ces range from 630 to 3250℃·d. The mean annual freezing index of the 7 stations exhibited decreasing trends with decreasing rate of ?16.6– ?59.1℃·d /10a. The mean annual thawing index of these 7 stations showed increasing trends with the related decreasing rate is 19.83–45.6℃·d /10a. 2) The MK trend test indicated the significant decreasing trends (sig-nificant at < 0.05 significant level) in the annual freezing index for most stations except for Golmud. The significant increasing trends can be observed in the annual thawing index for 4 stations except Golmud and Tuotuohe. Golmud was the only station with no trends in both annual freezing and annual thawing index.     

Potential for Coal-to-Liquids Conversion in the United States—Fischer–Tropsch Synthesis

The United States has the world’s largest coal reserves and Montana the highest potential for mega-mine development. Consequently, a large-scale effort to convert coal to liquids (CTL) has been proposed to create a major source of domestic transportation fuels from coal, and some prominent Montanans want to be at the center of that effort. We calculate that the energy efficiency of the best existing Fischer–Tropsch (FT) process applied to average coal in Montana is less than 1/2 of the corresponding efficiency of an average crude oil refining process. The resulting CO₂ emissions are 20 times (2000%) higher for CTL than for conventional petroleum products. One barrel of the FT fuel requires roughly 800 kg of coal and 800 kg of water. The minimum energy cost of subsurface CO₂ sequestration would be at least 40% of the FT fuel energy, essentially halving energy efficiency of the process. We argue therefore that CTL conversion is not the most valuable use for the coal, nor will it ever be, as long as it is economical to use natural gas for electric power generation. This finding results from the low efficiency inherent in FT synthesis, and is independent of the monumental FT plant construction costs, mine construction costs, acute lack of water, and the associated environmental impacts for Montana.

SPIDER—an interactive statistical tool for the analysis of spatially distributed data

Interactive statistical graphics are reviewed in the contexts of spatial data and geographical information systems (GIS). GIS provide the user with an active geographical view of the data—a map that can be used as an entry point to the data base. Prototype software—SPIDER—illustrates the possibilities of using statistical graphics as further views of the data, which can be made active and thus provide alternative means of querying the data. These views can be cross-referenced by 'linking'. It is argued that such a system can provide a very rich environment for pursuing exploratory statistical analysis of spatial data.     

Fourth International Symposium on the Harmonization of Quality Assurance Schemes for Analytical Laboratories

The IUPAC-ISO-AOAC Fourth Symposium onthe Harmonization of Quality AssuranceSchemes for Analytical Laboratories will be heldon 2 and 3 May 1991 at ISO Central Secretariat,1 rue de Varembé,Geneva,Switzerland.The aims of the Symposium are (1)using as a     

An Important Forum for the Future of the World’s Rivers: The 8th International Riversymposium in Brisbane

The8thInternationalRiversymposium washeldinBrisbane,Australiaon6-9September2005.The InternationalRiversymposium isan integralpartofBrisbane’sannualbroadbased culturalevent. TheQueensland Governmentisafoundation partneroftheInternationalRiverFoundation,fo…     

A Review of “The Geography of Bliss: One Grump's Search for the Happiest Places in the World”

In contrast to the conventional gravity model that estimates flows between cities of given sizes, the reverse gravity model attempts to reconstruct the theoretical gravitational attractions of cities from network flow data. This article introduces the particle swarm optimization (PSO) method in solving the reverse gravity model. With comparison to the linear programming (LP) and the simplified algebraic method (SAM), the advantages of the PSO method include flexibility in the impedance function and better goodness of fit. The method is applied to the case study of air passenger transport in China. The results indicate that estimated nodal attractions in cities are generally in line with their population sizes, but there are significant discrepancies between them. A close examination of the discrepancies reveals that a better developed tertiary sector and higher tourism revenue per capita are associated with overestimated attractions in air transport, and stronger railway dominance influences their underestimation. The changes of gravitational attractions in major cities from 2001 to 2008 indicate the declining dominance of the largest cities and a move toward a more balanced development in the air transport system of China.     

An Important Forum for the Future of the World＇s Rivers： The 8th International Riversymposium in Brisbane

The 8th Intemational Riversymposium was held in Brisbane, Australia on 6-9 September 2005. The Intemational Riversymposium is an integral part of Brisbane＇s annual broadbased cultural event. The Queensland Government is a foundation partner of the Intemational River Foundation, formed to secure the future of the Intemational and National Thiess Riverprize. The theme of symposium in this year is “Water and Food Security- Rivers in a Global Context” （ www.riversymposium.com ）. The Riversymposium provides a global forum which aims to make a difference to the declining state of rivers and waterways globally. Its strength lies in the breadth of its challenging program content of important keynote presentations and case studies of rivers in crisis, attracting a diverse range of national and intemational delegates. Some 450 scientists from 38 countries attended this conference, and about 100 papers were presented on the symposium in 2005.     

Reply to “Comments on Climatology: The Challenge for the Eighties Revisited”

Book reviews in this article

The Heated Debate: Greenhouse Predictions Versus Climate Reality. ROBERT C. BALLING JR. San Francisco: Pacific Research Institute for Public Policy, 1992. xxxvi and 195 pp., diags., tables, index, and biblio. $21.95 cloth (ISBN 0-936488-47-6).

Mountain Weather and Climate, 2nd edition. ROGER G. BARRY. New York: Routledge, Chapman and Hall, 1992. xx and 402 pp., maps. diags., photos, index, and biblio. $89.95 cloth (ISBN 0-415-07112-7); $29.95 paper (ISBN 0-415-07113-5).

Late Quaternary Environmental Change: Physical and Human Perspectives. MARTIN BELL and MICHAEL J. C. WALKER. Essex, England: Longman Group, 1992. xiv and 273 pp., maps, diags., index, and biblio. $39.95 paper (ISBN 0-582-04514-2).

Planning for Earthquakes. PHILIP R. BERKE and TIMOTHY BEATLEY. Baltimore: The Johns Hopkins University Press, 1992. xv and 210 pp., maps, diags., photos, tables, app., acronyms, index, and biblio. $38.00 cloth (ISBN 0-8018-4255-7).

Industrialization and Development in the Third World. RAJESH CHANDRA. London: Routledge, 1992. xvii and 124 pp., maps, figs., photos, and index. $14.95 paper (ISBN 0-415-01380-1).

Waste Location: Spatial Aspects of Waste Management, Hazards and Disposal. MICHAEL CLARK, DENIS SMITH, and ANDREW BLOWERS, eds. London: Routledge, 1992. xv and 257 pp., maps, diags., index, and refs. $85.00 cloth (ISBN 0-415-04824-9).

Water Diversion and Export: Learning from Canadian Experience. J. C. DAY and FRANK QUINN. Waterloo, Ontario: Department of Geography, University of Waterloo, 1992. xx and 215 pp., 14 maps, 4 diags., 17 tables, 12 photos, glossary, and biblio. $25.00 (Can.) paper (ISBN 0-921083-42-4).

The Native Population of the Americas in 1492, 2nd edition. WILLIAM M. DENEVAN, ed. Madison: The University of Wisconsin Press, 1992. xxxviii and 353 pp., maps, figs., tables, index, biblio. $45.00 cloth (ISBN 0-299-134-30-X); $14.95 paper (ISBN 0-299-13434-2).

Touring North America (series). ANTHONY R. DE SOUZA, ed. New Brunswick: Rutgers University Press, 1992. 13 volumes; pages varying from approximately 100 to approximately 300 each; maps, diags., indices, and biblios. $9.95 each paperback; $25.00 each volume in cloth; boxed gift set of all 13 volumes in paperback $129.95. (ISBNs for cloth and paperback editions range from 0-8135-1870-9 to 0-8135-1895-4 inclusive).

Urban Transport Planning: A Developmental Approach. HARRY T. DIMITRIOU. New York: Routledge, 1992. xviii and 346 pp., diags., index, and biblio. $92.50 cloth (ISBN 0-415-03857-X).

Colonialism and Development in the Contemporary World. CHRIS DIXON and MICHAEL HEFFERNAN, eds. Rutherford, NJ: Mansell, 1991. viii and 232 pp., maps, diags., index, and biblio. $70.00 cloth (ISBN 0-7201-2072-1).

The Betweenness of Place: Towards a Geography of Modernity. J. NICHOLAS ENTRIKIN. Baltimore: The Johns Hopkins University Press, 1991. xii and 196 pp., notes, and indices. $38.50 cloth (ISBN 0-8018-4083-X); $13.95 paper (ISBN 0-8018-4084-8).

The Women Outside: Meanings and Myths of Homelessness. STEPHANIE GOLDEN. Berkeley: University of California Press, 1992. ix and 265 pp., index and biblio. $25.00 cloth (ISBN 0-520-07158-1).

The Transformation of Agriculture in the West. DAVID GRIGG. Oxford, England, and Cambridge, MA: Basil Blackwell, 1992. xiv and 141 pp., maps, diags., index, and biblio. $19.95 paper (ISBN 0-631-17094-4).

Derelict Landscapes: The Wasting of America's Built Environment. JOHN A. JAKLE and DAVID WILSON. Savage, MD: Rowman and Littlefield, 1992. xviii and 342 pp., illus., index, biblio. $65.00 cloth (ISBN 0-8476-7735-4); $23.50 paper (ISBN 0-8476-7736-2).

Iranian Cities: Formation and Development. MASOUD KHEIRABADI. Austin: University of Texas Press, 1991. xiv and 132 pp., maps, diags., photos, appendices, notes, glossary, biblio., and index. $27.50 cloth (ISBN 0-292-72468-3).

The Pentagon and the Cities. ANDREW KIRBY, ed. Newbury Park, CA: Sage Publications, 1991. Urban Affairs Annual Reviews, vol. 40. x and 207 pp., tables, maps, index, and biblio. $43.95 cloth (ISBN 0-8039-3845-4); $19.95 paper (ISBN 0-8039-3846-2).

Geographic Perspectives on Soviet Central Asia. ROBERT A. LEWIS, ed. London and New York: Routledge, 1992. xv and 323 pp., maps, diags., index, and biblio. $69.95 cloth (ISBN 0-415-07592-0).

Conquest and Survival in Colonial Guatemala: A Historical Geography of the Cuchumatan Highlands, 1500–1821. W. GEORGE LOVELL. Montreal and Kingston: McGill-Queen's University Press, 1992. xxxviii and 279 pp., maps, diags., glossary, notes, index, and biblio. $19.95 paper (ISBN 0-7735-0903-8).

Contested Lands: Conflict and Compromise in New Jersey's Pine Barrens. ROBERT J. MASON. Philadelphia: Temple University Press, 1992. xii and 257 pp., maps, tables, index, and biblio. $44.95 cloth (ISBN 0-87722-925-2).

Making Sense of Place: Children's Understanding of Large-Scale Environments. M. H. MATTHEWS. Savage, MD: Harvester Wheatsheaf, Barnes and Noble Books, 1992. xiv and 271 pp., maps, diags, tables, index, and biblio. $54.50 cloth (ISBN 0-389-20987-2).

Sources of Metropolitan Growth. EDWIN S. MILLS and JOHN F. MCDONALD, eds. New Brunswick: Center for Urban Policy Research Press, 1992. xxvii and 306 pp., maps, diags., index, and biblio. $29.95 cloth (ISBN 0-88285-135-7).

Resource Management in Developing Countries. PETER H. OMARAOJUNGU. Harlow, England: Longman, 1992. xvi and 213 pp., maps, diags., tables, index, and biblio. $39.95 paper (ISBN 0-582-30102-5).

A Moveable Shore: The Fate of the Connecticut Coast. PETER C. PATTON and JAMES M. KENT. Durham: Duke University Press, 1992. viii and 143 pp., maps, diags., index, and biblio. $49.95 cloth (ISBN 0-8223-1128-3); $19.95 paper (ISBN 0-8223-1147-X).

Agricultural Reform in China: From Communes to Commodity Economy 1978–1990. SIMON G. POWELL. Manchester, England: Manchester University Press, 1992. viii and 231 pp., maps, diags., tables, and biblio. $69.95 cloth (ISBN 0-7190-3382-9).

The Caribbean in the Wider World, 1492–1992: A Regional Geography. BONHAM C. RICHARDSON. Cambridge: Cambridge University Press, 1992. xvi and 235 pp., maps, tables, index, and biblio. $49.95 cloth (ISBN 0-521-35186-3); $16.95 paper (ISBN 0-521-35977-5).

Scavengers, Recyclers, and Solutions for Solid Waste Management in Indonesia. DANIEL T. SICULAR. Berkeley: Center for Southeast Asian Studies, University of California at Berkeley, 1992. xii and 197 pp., maps, tables, photos, glossary, biblio., and index. $16.50 paper (ISBN 0-944613-13-6).

The Sphinx in the City: Urban Life, the Control of Disorder, and Women. ELIZABETH WILSON. Berkeley: University of California Press, 1992. 191 pp., plates, index, and biblio. $35.00 cloth (ISBN 0-520-07850); $14.00 paper (ISBN 0-520-07864-0).

The Cultural Geography of the United States: A Revised Edition. WILBUR ZELINSKY. Englewood Cliffs: Prentice Hall, Inc., 1992. ix and 226 pp., maps, diags., index, and biblio. $21.95 paper (ISBN 0-13-194424-X).     

Social Networks as Livelihood Strategies for Small-scale Traders on the Thai–Lao Border

ABSTRACT

Small scale cross-border trade on the Thai–Lao border has come under increasing pressure with the construction of a new Mekong bridge that has expanded formal trade between the two countries. Most small-scale traders are women who, with assistance from family and friends, have developed small businesses from childhood, and created social networks across the border with other traders, and relevant actors such as drivers and government officials. Such networks, trust, experience and familiarity enabled superior access to information and trading concessions that have enabled the continued success of small-scale trade, the maintenance of complex cross-border livelihoods, and the ability of traders across an increasingly regulated border to deal with constraints and risks. A few established traders have developed trade networks and social relationships involving supply chains across several countries.     

Bargaining for nature: treating the environment in China’s urban planning practice

ABSTRACT

In much of the contemporary academic inquiry and political discourse on Chinese cities, urban entrepreneurialism and environmentalism often appear to be analyzed disjointedly and unreflectively. They are portrayed as two conflicting interests. Commentators also view urban planners as a homogenous group of professionals and/or state agents being forced to give up environmental goals to pursue economic value of space. Using the case of Tianjin Eco-City planning, this article interrogates the bargaining process between the “ecological value” and “commodity narrative”. It offers three major arguments. First, even though the discourse of environmental sustainability has been used to legitimize economic transformation, ecological demands are creating new pressures on entrepreneurial urban governance. Second, rather than treating Chinese planners as a fully constituted, internally coherent, organizationally-fixed, and operationally-consistent group, they should be viewed as hybrid, and diverse entities that represent divergent and sometimes contentious state interests. Third, planners, though still under tremendous pressure from landed interests, can become active players to positively influence urban transformation toward more environmental care.     

A condition for the formation of Antarctic Bottom Water in Prydz Bay， Antarctica

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