scholarly journals Two metropolisation gradients in the European system of cities revealed by scaling laws

2018 ◽  
Vol 46 (9) ◽  
pp. 1645-1662 ◽  
Author(s):  
Denise Pumain ◽  
Céline Rozenblat
Keyword(s):  
Diffusion Of Innovation ◽  
Urban Areas ◽  
Scaling Laws ◽  
Relative Concentration ◽  
Urban System ◽  
Structural Features ◽  
Urban Systems ◽  
Hierarchical Diffusion ◽  
European System ◽  
System Of Cities

Urban systems share with other complex systems constraints on their dynamics that are revealed by pervasive structural features, among which scaling laws. Scaling laws are relationships between cities’ attributes and their size (here measured by their population). When the relationship is non proportional with exponents larger than 1, scaling laws indicate the relative concentration of some urban functions at the higher levels of urban hierarchies. Superlinear scaling thus reveals the metropolisation trends that are produced in the urban system, according to our evolutionary theory perspective, by the hierarchical diffusion of innovation waves. Considering the current urban changes linked with the globalisation processes as an ‘innovation’ that is likely to diffuse hierarchically in urban systems, we analyse the relationships between 25 indicators expressive of their position in globalisation processes and the size of European cities (356 largest functional urban areas of the 28 European Union member states plus Switzerland and Norway). When summarised in a single metropolisation factor, we expected to find a unique superlinear scaling relationship that would reveal the hierarchical structure of the unifying European system of cities. We instead identify two distinct metropolisation gradients for each of the Western and Eastern subsystem that we interpret according to the delayed globalisation process in the latter. This provides a demonstration of the usefulness of scaling laws for summarising stages in the process of hierarchical diffusion of innovation in systems of cities.

scholarly journals THE EVALUATION OF VISUAL INFLUENCES ON THE ENVIRONMENT OF IVANO-FRANKIVSK CITY

2018 ◽  
pp. 44-51
Author(s):  
T. V. Kundelska ◽  
M. T. Mykytsei
Keyword(s):  
Urban Areas ◽  
Visual Fields ◽  
Urban System ◽  
Waste Utilization ◽  
Urban Systems ◽  
Evaluation Procedure ◽  
Visual Environment ◽  
Visual Evaluation ◽  
Normative Documents ◽  
Visual Impact

The article deals with the problems of urban systems visual contamination which is connected with the issues of noise and electromagnetic loading, waste utilization and storage, water resources pollution, and which depends entirely on the environmental situation within the cities. The paper analyzes Ukrainian and foreign publications on the factors of visual evaluation, particularly the calculation of the coefficient of videoecological susceptibility of the territory, the statistical analysis of visual pollution estimation based on the poll of the respondents who are exposed to negative visual impact. The authors reveal that in Ukraine there are no normative documents which regulate the procedure for the estimation of visual contamination. The article presents the main drawbacks and unresolved parts of the general problem of visual impact evaluation. The authors of the publication suggest a generalized method for conducting a visual evaluation of urban areas. The results of the estimation are presented using the urban system Ivano-Frankivsk as the example. The main stages of the evaluation of visual influences are highlighted. These stages are the city zoning according to the presence and types of dominant visual objects, the clarification of the list of those criteria which are necessary to evaluate the quality of the visual environment, the choice of the optimal solution concerning the evaluation procedure and regarding the selection of the appropriate number of points on the urban system territory, and, finally, carrying out the evaluation itself in accordance with thirty criteria.  The authors of the publication substantiate visual evaluation procedure based on the suggested method together with some elements of the method of multi-criteria analysis. Using the results of the evaluation, the authors construct the map of visual influences and carry out a complex spatial analysis of the visual fields of Ivano-Frankivsk. The article solves the problem of comprehensive evaluation of the ecological situation of urbanized systems and living conditions of the population, taking into account the evaluation of the visual environment quality.

scholarly journals Modeling Fractal Structure of Systems of Cities Using Spatial Correlation Function

2010 ◽  
Vol 1 (1) ◽  
pp. 12-34 ◽  
Author(s):  
Yanguang Chen ◽  
Shiguo Jiang
Keyword(s):  
Correlation Function ◽  
Spatial Correlation ◽  
Fractal Dimensions ◽  
Urban System ◽  
Urban Systems ◽  
Box Dimension ◽  
Spatial Correlation Function ◽  
Time Space ◽  
Correlation Exponent ◽  
System Of Cities

This article proposes a new method to analyze the spatial structure of urban systems using ideas from fractals. Regarding a system of cities as a set of “particles” distributed randomly on a triangular lattice, we construct a spatial correlation function of cities. Suppose that the spatial correlation follows the power law. It can be proved that the correlation exponent is the second order generalized dimension. The spatial correlation model is applied to the system of cities in China. The results show that the Chinese urban system can be described by the correlation dimension ranging from 1.3 to 1.6. The fractality of self-organized network of cities in both the conventional geographic space and the “time” space is revealed with the empirical evidence. The spatial correlation analysis is significant in that it is applicable to both large and small sizes of samples and can be used to link different fractal dimensions in urban study, including box dimension and radial dimension.

Are the absent always wrong? Dealing with zero values in urban scaling

2018 ◽  
Vol 46 (9) ◽  
pp. 1663-1677 ◽  
Author(s):  
Olivier Finance ◽  
Clémentine Cottineau
Keyword(s):  
Foreign Investment ◽  
Scaling Laws ◽  
Empirical Studies ◽  
Urban System ◽  
Ordinary Least Squares ◽  
Urban Systems ◽  
Zero Values ◽  
Urban Scaling ◽  
Definition Of

Both theoretical and empirical studies have shown the ability of scaling laws to reveal processes of emergence in urban systems. Nevertheless, a controversy about the robustness of results obtained with these models on empirical cases remains, regarding for instance the definition of the ‘city’ considered or the way the estimations are performed. Another source of bias is highlighted in this contribution, with respect to the non-ubiquitous character of some urban attributes (i.e. their partial absence from several cities of the system). The problem with the zero count for cities where these attributes are absent is that the technical necessities of usual estimation procedures make the analysis ignore them altogether even when they represent some valid information. This could seriously impact the results. A precise exploration of the effects of this arbitrary filtering is conducted here, and several solutions are proposed to overcome this limitation. In a case study about foreign investment towards French cities, we show that some erroneous conclusions about a hierarchical diffusion could be drawn when adopting the classical ordinary least squares approach. The framework we suggest specifies how it is possible to avoid misinterpretations deriving from the exclusion of zero values by using methods of analysis which deal with zero values specifically. The conclusion of a diffusion of foreign investment in the French urban system is then rejected.

scholarly journals Using the State Space of a BLV Retail Model to Analyse the Dynamics and Categorise Phase Transitions of Urban Development

Urban Science ◽  
2019 ◽  
Vol 3 (1) ◽  
pp. 31 ◽  
Author(s):  
Joel Dearden ◽  
Yi Gong ◽  
Mark Jones ◽  
Alan Wilson
Keyword(s):  
Urban Development ◽  
State Space ◽  
Urban Areas ◽  
Initial Conditions ◽  
Urban System ◽  
Urban Systems ◽  
Complex Nature ◽  
Urban Dynamics ◽  
Shopping Centre ◽  
Human Habitat

Urban areas are now the dominant human habitat, with more influence than ever on economies, environment and our health. Dynamic urban models are increasingly applied to explore possible future scenarios of urban development to achieve sustainability. However, it is still challenging to use these models for prediction, taking into consideration the complex nature of urban systems, the nonlinear interactions between different parts of the system, and the large quantities of data output from simulations. The aim of this study is to analyse the dynamics of two hypothetical dynamic BLV (Boltzmann–Lotka–Volterra) retail models (two-zone and three-zone). Here, by visualising and analysing the qualitative nature of state space (the space of all possible initial conditions), we propose an alternative way of understanding urban dynamics more fully. This involves examining all possible configurations of an urban system in order to identify the potential development in future. Using this method we are able to identify a supply-demand balancing hyperplane and categorise two causes of phase transition of urban development: (A) change in variable values (e.g., building a new shopping centre) that cause the system to cross a basin boundary, (B) state space change (e.g., construction of a new motorway changes travel costs in the region) causes the containing basin to be modified. We also identify key characteristics of the dynamics such as velocity and how the phase space landscape changes over time. This analysis is then linked with equilibrium-size graphs, which allow insights from state space to be applicable to models with large numbers of zones. More generally this type of analysis can potentially offer insights into the nature of the dynamics in any dynamical-systems-type urban model. This is critical for increasing our understanding and helping stakeholders and policy-makers to plan for future urban changes.

scholarly journals Urban scaling in Europe

2016 ◽  
Vol 13 (116) ◽  
pp. 20160005 ◽  
Author(s):  
Luís M. A. Bettencourt ◽  
José Lobo
Keyword(s):  
Urban Areas ◽  
Western Europe ◽  
Urban System ◽  
Statistical Procedure ◽  
Urban Systems ◽  
Scaling Relations ◽  
Scaling Effects ◽  
Economic Productivity ◽  
European Cities ◽  
Urban Scaling

Over the last few decades, in disciplines as diverse as economics, geography and complex systems, a perspective has arisen proposing that many properties of cities are quantitatively predictable due to agglomeration or scaling effects. Using new harmonized definitions for functional urban areas, we examine to what extent these ideas apply to European cities. We show that while most large urban systems in Western Europe (France, Germany, Italy, Spain, UK) approximately agree with theoretical expectations, the small number of cities in each nation and their natural variability preclude drawing strong conclusions. We demonstrate how this problem can be overcome so that cities from different urban systems can be pooled together to construct larger datasets. This leads to a simple statistical procedure to identify urban scaling relations, which then clearly emerge as a property of European cities. We compare the predictions of urban scaling to Zipf's law for the size distribution of cities and show that while the former holds well the latter is a poor descriptor of European cities. We conclude with scenarios for the size and properties of future pan-European megacities and their implications for the economic productivity, technological sophistication and regional inequalities of an integrated European urban system.

Visualizing resource dependencies of the urban system at multiple scales: a hydrological case study

2020 ◽  
Author(s):  
Héctor Angarita ◽  
Vishal Mehta ◽  
Efraín Dominguez
Keyword(s):  
Urban Planning ◽  
River Basin ◽  
Urban Areas ◽  
Multiple Scales ◽  
Urban System ◽  
Resource Dependency ◽  
Urban Systems ◽  
Freshwater Systems ◽  
Novel Approach ◽  
Freshwater System

<p>Freshwater is one key component of the resource dependency of urban areas, linking concentrated population centers to geophysical and ecosystem processes operating at regional and global scales. Resources like water, food, biofuels, fibers or energy that sustain cities directly depend on the productive or assimilative capacities of the hydrological system, operating at multiple nested scales (from catchment to river basins) —areas orders of magnitude greater than the extent of the built-up urban areas.</p><p>Although the freshwater systems–urban population relationship has a broad regional and sectorial scope, the quantification of the extent of regional and global impacts of cities’ resource demands, and more importantly, their integration into decision-support frameworks continues to be overlooked in water-management and urban planning practice. A key limitation of understanding the scope of impacts of urban systems is the characterization of the distributed and non-linear nature of the regional relationship of water and cities, wherein a given region can simultaneously supply resources to—or be affected by—multiple urban areas (and vice-versa), and the heterogeneity of physical and biotic processes of freshwater systems.</p><p>Here we introduce a novel approach to assess and visualize the interactions between urban resource demands and the freshwater system. We propose a set of indicators that make use of freshwater drainage structure to incorporate the cumulative effects and concurrent resource dependency of urban areas across multiple nested scales. The cumulative character of the proposed indexes aims to replace the fixed control boundary (i.e. basin, sub-basin, etc -the current practice in water resources appraisals), with the (topological) integral of the process across the multiple nested scales present in a river basin. This approach allows: (i) visualizing how factors like patterns of size, spatial distribution and interconnection of urban resource demands or the nested and hierarchical character of freshwater systems, influence the cumulative pressure exerted or a urban system on the freshwater system, (ii) mapping the spatial patterns of resource import and export across different scales and regions of a freshwater system, and (iii) quantifying the scales of the process required to sustain the resource supply of the multiple cities sharing the same provisioning freshwater system. The presented advances can inform regional urban planning to determine options to avoid, minimize or offset regional impacts of urban populations. An example of this proposed approach is presented for the Magdalena River Basin (Colombia).</p>

Engineering in the time of cholera: overcoming institutional and political challenges to rebuild Zimbabwe's water and sanitation infrastructure in the aftermath of the 2008 cholera epidemic

2013 ◽  
Vol 3 (2) ◽  
pp. 222-229 ◽  
Author(s):  
Clarissa Brocklehurst ◽  
Murtaza Malik ◽  
Kiwe Sebunya ◽  
Peter Salama
Keyword(s):  
Urban Areas ◽  
Large Scale ◽  
Humanitarian Aid ◽  
Urban Systems ◽  
Political Crisis ◽  
Rapid Improvement ◽  
Cholera Epidemic ◽  
Rapid Action ◽  
Water And Sanitation Infrastructure ◽  
Urban Rehabilitation

A devastating cholera epidemic swept Zimbabwe in 2008, causing over 90,000 cases, and leaving more than 4,000 dead. The epidemic raged predominantly in urban areas, and the cause could be traced to the slow deterioration of Zimbabwe's water and sewerage utilities during the economic and political crisis that had gripped the country since the late 1990s. Rapid improvement was needed if the country was to avoid another cholera outbreak. In this context, donors, development agencies and government departments joined forces to work in a unique partnership, and to implement a programme of swift improvements that went beyond emergency humanitarian aid but did not require the time or massive investment associated with full-scale urban rehabilitation. The interventions ranged from supply of water treatment chemicals and sewer rods to advocacy and policy advice. The authors analyse the factors that made the programme effective and the challenges that partners faced. The case of Zimbabwe offers valuable lessons for other countries transitioning from emergency to development, and particularly those that need to take rapid action to upgrade failing urban systems. It illustrates that there is a ‘middle path’ between short-term humanitarian aid delivered in urban areas and large-scale urban rehabilitation, which can provide timely and highly effective results.

scholarly journals Health in cities: Getting out and about as we age

2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
T Ma ◽  
R Ivers ◽  
E de Leeuw ◽  
K Clapham ◽  
C Kobel
Keyword(s):  
Older People ◽  
Policy Making ◽  
Urban System ◽  
Transportation Systems ◽  
Social Contexts ◽  
Urban Systems ◽  
Activity Levels ◽  
The Public ◽  
Housing Developments ◽  
Health Community

Abstract Transportation influences health through its effects on people's access to goods, services, and life chance opportunities; social interactions; physical activity levels; air pollution exposures; and road injury risks. Given the ageing of populations, it is essential that decisions about land use and transportation systems are appropriate to meet the mobility needs of older people and support healthy ageing. Not all transportation options, however, may be accessible to older people. Factors that affect accessibility relate to the spatial and physical characteristics of places, personal and social contexts of individuals, and rules and norms underpinning planning and policy making. This research aimed to understand how different parts and processes of urban systems interact to influence transportation options for older people. Using the Greater Sydney area as a case, we drew on key informant interviews and public policy documents to identify the considerations that inform planning and policy making as they pertain to the nature of cities and the opportunities of older people to get out and about. We compared and integrated these findings with peer-reviewed literature of similar urban growth areas. Our analysis mapped the factors of the human-urban system that are central to enabling transportation mobility for older people, articulated their interrelationships, and identified the actors that influence them. Our results point to the involvement of actors from the public health, community development, transportation, and urban planning sectors at multiple levels of government. Each of these actors operate within their own remit to influence a part of the urban system relevant to older people's transportation, such as the zoning of land, the approval of housing developments, and the location of bus stops. However, these individual actions are constrained by others in the system. We interpret this complexity with a governance lens. Key messages Efforts to promote mobility in old age should move beyond ‘single solutions to single issues’ approaches toward those that reflect the complexity of cities and the ways that people move within them. For sustained realization of desired outcomes, age-friendly initiatives cannot occur in isolation, but rather must take into account the behaviours and dynamics of the urban system.

Ancient colonialism and the economic geography of the Mediterranean

2020 ◽  
Author(s):  
Dimitris K Chronopoulos ◽  
Sotiris Kampanelis ◽  
Daniel Oto-Peralías ◽  
John O S Wilson
Keyword(s):  
Population Density ◽  
Economic Geography ◽  
Economic Activity ◽  
Mediterranean Region ◽  
Historical Data ◽  
Urban System ◽  
Current Data ◽  
Origin And Evolution ◽  
System Of Cities ◽  
The Mediterranean

Abstract This article investigates the legacy of ancient Phoenician, Greek and Etruscan colonialism in shaping the economic geography of the Mediterranean region. Utilising historical data on ancient colonies and current data on population density and night light emissions (as a proxy for economic activity), we find that geographical areas colonised by these ancient civilisations have higher population density and economic activity in the present day. We also find that ancient colonialism affected the origin and evolution of the urban system of cities and settlements prevalent in the Mediterranean region.

scholarly journals Community Preferences for Urban Systems Transformation in Australia

2021 ◽  
Vol 13 (9) ◽  
pp. 4749
Author(s):  
Milo Costanza-van den Belt ◽  
Tayanah O’Donnell ◽  
Robert Webb ◽  
Eleanor Robson ◽  
Robert Costanza ◽  
...  
Keyword(s):  
Decision Making ◽  
Urban Areas ◽  
Online Survey ◽  
Shared Vision ◽  
Urban Systems ◽  
Urban Structure ◽  
Sustainable Cities ◽  
Community Needs ◽  
National Workshop ◽  
Systems Transformation

Civil society engagement is important for enabling urban systems transformations that meet community needs. The development of Future Earth Australia’s Sustainable Cities and Regions: A 10-Year Strategy for Urban Systems was underpinned by cross-sectoral workshops in 7 Australian urban areas and interviews with key stakeholders to create a shared vision of both current and desired future urban structure and policy. We then created an online survey to gauge broader community feedback on the vision which emerged from these workshops and interviews, to compare their outcomes with the views of community members who could be directly impacted by urban decision-making. The survey consisted of 35 questions, which were shaped by the issues emerging from the workshops and interviews. The sample was self-selected, and the 641 respondents represented a cross-section of individuals interested in sustainable cities. Our survey results supported and expanded on the major conclusions of FEA’s National workshop and interview processes, including the need to develop transparent and responsive decision-making processes, limit waste and pollution and develop effective housing and transport alternatives with mixed-use neighborhoods and adequate green space.

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