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The Sustainable Development Goals require us to rethink spatial planning policies' effectiveness. This article proposes a reproducible method for assessing the effect of past planning practices and simulating future land-use and land-cover (LULC) changes with a Cellular Automata model. The originality of our approach is to systematically compare observed changes in LULC with the planning rules in force over almost a century of evolution. A quasi-exhaustive database was constructed at a very fine spatial resolution for the municipality of Portimão (Southern Portugal), including the location and changes of LULC categories, and the planning rules of the corresponding time period on nine dates between 1947 and 2018. The quantified measurement of the actual effect of planning rules enables us to identify other determinants of the evolution. Findings reveal that the policies established by the local government—which aimed to foster well-planned comprehensive urban areas—were not as effective as intended. The quantified discrepancies between planning recommendations and observed evolution help to simulate which LULC scenarios could be designed to reach the expected result in future planning policies. Our assessment method could be applied in other urban and tourist regions where land artificialization exerts strong pressure on the environment. [ABSTRACT FROM AUTHOR]

In this commentary we reflect on the potential and power of geographical analysis, as a set of methods, theoretical approaches, and perspectives, to increase our understanding of how space and place matter for all. We emphasize key aspects of the field, including accessibility, urban change, and spatial interaction and behavior, providing a high‐level research agenda that indicates a variety of gaps and routes for future research that will not only lead to more equitable and aware solutions to local and global challenges, but also innovative and novel research methods, concepts, and data. We close with a set of representation and inclusion challenges to our discipline, researchers, and publication outlets. [ABSTRACT FROM AUTHOR]

This study investigates the role of ports in the dynamics of the city size distribution in a system of cities based on their geospatial proximity. We used an interdisciplinary method based on the complex systems approach to explore the participation of ports in the urban hierarchy. We used the case of the Mexican urban system and its national port system, data from 1900 to 2010. We tested the assumption of universality in spatial systems applying an inferential data analysis classifying probability distribution functions associated with the city size measure. We identified cities associated with their closest port across the rank size distribution and mapped their spatial location. Findings suggested that top hierarchical cities have been associated with three port sites: Veracruz, Tuxpan, and Lazaro Cardenas. They have consolidated their importance even though the entrance of new ports in the urban system. However, these new ports have affected the large-scale behavior of the urban system. The dynamics of statistical distributions showed a trend from skewed to non-skewed distributions indicating that the system remains complex, but it has changed its large-scale behavior, from higher influence of large to medium city sizes. [ABSTRACT FROM AUTHOR]

European cities may be regarded as having formed a system of well-interconnected entities over many centuries. The peculiarities of their hierarchical functional organization and territorial patterns have been extensively analysed. This study details a few contributions from the science of complex systems meant to formalize this knowledge. This includes a representation of the metropolisation process occurring within a system of cities with the help of scaling laws and network analysis. We define the metropolisation process - not at the local level of one metropolitan area but at a macro-geographical level - as the ability of larger cities to capture the activities related to innovation waves and to be the first to benefit from these in terms of population growth. A series of urban attributes are used to quantify, through exponents of scaling laws the differentiated behaviour of urban hierarchies when opening up to the global networks that characterize the most recent wave of innovation. Network analysis provides another type of formalism that helps us construct a better understanding of how globalization processes, especially the spread of multinational firms, have diffused in the Eastern part of the European urban system. [ABSTRACT FROM AUTHOR]

Copyright of Papers in Regional Science is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Zipf's rank-size rule, lognormal distribution, and Gibrat's urban growth models are considered as summarizing fundamental properties of systems of cities. In this article, they are used as statistical benchmarks for comparing the shapes of urban hierarchies and evolutionary trends of seven systems of cities in the world including BRICS, Europe, and United States. In order to provide conclusions that avoid the pitfalls of too small samples or uncontrolled urban definitions, these models are tested on some 20,000 urban units whose geographically significant delineations were harmonized in each country over 50 years between 1960 and 2010. As a result, if the models appear not always statistically valid, their usefulness is confirmed since the observed deviations from empirical data remain limited and can often be interpreted from the geohistorical context of urbanism proper to each world region. Moreover, the article provides new free software which authorizes the reproducibility of our experiments with our data bases as well as with complementary data. [ABSTRACT FROM AUTHOR]

Copyright of Mitteilungen der Österreichischen Geographischen Gesellschaft is the property of Oesterreichische Geographische Gesellschaft (Austrian Geographical Society) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Agent-based models are increasingly used by urban specialists, supplanting the simulation models using differential equations which were more popular earlier. These models already made reference to the theories of self-organisation and to mechanisms of evolution not so far from those used today to describe the emergence of macroscopic properties or structures in a bottom-up process from interactions operating at the microlevel. Moreover there is less difference than often suggested in the literature between the two forms of modelling - differential equations and multi-agent models--in the way they integrate principles of urban theory. To test this assumption, we compare models made of systems of differential equations (Allen's model firmly rooted in self-organisation theory and the model developed by Weidlich and Haag, affiliated to synergetic theory) with multi-agent models (SIMPOP family) designed to meet the same task: simulating the differentiated dynamics of urban entities over the medium to long term from their functional economic specialisation. We show that multi-agent systems are providing interesting solutions for the modelling method, because of their greater ability to simulate the emergence of geographical macrostructures from different levels of interaction. [ABSTRACT FROM AUTHOR]

The article discusses an urban growth geographical model designed to simulate spatial interaction and innovation cycles within a set of cities. The use of theoretical simulations to show that the model is capable of reproducing the urban system properties for the log-normal distribution and observed distribution is discussed. The article suggests that Gibrat's generic stochastic growth model be replaced by a spatially and temporally interdependent geographical model.

Simpop2 is a generic multi-agent model designed for simulating any system of cities. From an evolutionary theory built upon the observation of networks of cities in different parts of the world and over long time-periods, it has been possible to identify stylised facts that characterise their main features and properties. This paper presents data-oriented simulations of two kinds of system: in early settled countries (Europe, 1300—2000) and in countries more recently settled (the United States, 1650—2000). The model can simulate properly the general dynamics of urban systems, at different scales of observation (general configuration and trajectories of individual cities). The simulations help to identify some dynamic properties that are shared by both systems: a general growth trend and spatial expansion (produced through interurban competition which generates emulation towards innovation that explain the persistency of the hierarchical configuration); a dramatic increase of contrasts in city sizes since the first industrial revolution linked to the increase of communication speed; and, a differentiation of urban economic functions produced through interactions between cities and innovation cycles, as industrial revolution. The model also puts forward the necessary integration of a new urban function in the model, which represents the early emergence of global cities. Yet, beyond these similarities in the evolution of all urban systems, when they are fully integrated, the model also measures to what extent the observed peculiarities in their contemporary spatial and functional configuration depend on differences in the early space-filling process between the two kinds of system. [ABSTRACT FROM PUBLISHER]

Abstract. We define the urban field as the spatial organisation of urban densities according to decreasing gradients from centre to periphery. This urban field can be estimated from the encroachment of built-up areas. The CORINE Land Cover database enables the measurement of the gradient values for the spatial distribution of built-up areas in European cities. Instead of the exponential or power functions, which usually provide the best fit for the distributions of population densities, we find that two linear functions strongly differentiating a central and a peripheral gradient provide the best fit for built-up surfaces. The comparison between the 1990 and 2000 CORINE images demon- strates a convergence in the trend of urban spread between Northern and Southern European cities. However, it is still difficult from the data to decide which of the models of urban field is winning: will the steeper central gradient become diluted into the less dense periphery, or are the closer fringes of the central parts becoming integrated into the ordered pattern of the urban central agglomerations? [ABSTRACT FROM AUTHOR]

The progress of political and economic integration among European countries is inducing the progressive emergence of a European urban system. National urban systems are restructuring and adapting themselves to this new international and economic context. The location of the largest multinational firms is taken as revealing a major step in the process of the integration of European cities into supra-national networks. A survey of the location of 3000 establishments belonging to the 300 largest European firms provides interesting results about the factors making European cities attractive for such activities. It may be inferred from these results that they confirm a new trend called `metropolisation', which is reinforcing the top of the national urban hierarchies, as demonstrated in other studies. [ABSTRACT FROM PUBLISHER]

Discusses the emergence of a European urban system and takes the location of the largest multinational firms as revealing a major step in the process of metropolization. Metropolization; European urban system; Location of multinational firms.

Copyright of Population (00324663) is the property of Institut National d'Etudes Demographiques and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Cities are facing many sustainability issues in the context of the current global interdependency characterized by an economic uncertainty coupled to climate changes, which challenge their local policies aiming to better conciliate reasonable growth with livable urban environment. The urban dynamic models developed by the so-called "urban science" can provide a useful foundation for more sustainable urban policies. It implies that their proposals have been validated by correct observations of the diversity of situations in the world. However, international comparisons of the evolution of cities often produce unclear results because national territorial frameworks are not always in strict correspondence with the dynamics of urban systems. We propose to provide various compositions of systems of cities in order to better take into account the dynamic networking of cities that go beyond regional and national territorial boundaries. Different models conceived for explaining city size and urban growth distributions enable the establishing of a correspondence between urban trajectories when observed at the level of cities and systems of cities. We test the validity and representativeness of several dynamic models of complex urban systems and their variations across regions of the world, at the macroscopic scale of systems of cities. The originality of the approach resides in the way it considers spatial interaction and evolutionary path dependence as major features in the general behavior of urban entities. The models studied include diverse and complementary processes, such as economic exchanges, diffusion of innovations, and physical network flows. Complex systems dynamics is in principle unpredictable, but contextualizing it regarding demographic, income, and resource components may help in minimizing the forecasting errors. We use, among others, a new unique source correlating population and built-up footprint at world scale: the Global Human Settlement built-up areas (GHS-BU). Following the methodology and results already obtained in the European GeoDiverCity project, including USA, Europe, and BRICS countries, we complete them with this new dataset at world scale and different models. This research helps in further empirical testing of the hypotheses of the evolutionary theory of urban systems and partially revising them. We also suggest research directions towards the coupling of these models into a multi-scale model of urban growth. [ABSTRACT FROM AUTHOR]

Focuses on the impact of the urban system on the evolution of human settlements. Criticisms regarding localization of agglomeration economies; Correlation between urbanization and communication; Relevance of evolutionary spatial entities on geographical forecasts.

Many controversial questions about the shape and evolution of city size distributions can be solved if reliable, large and comparable setof data are used for several countries. We provide new empirical evidence by using the large data base 'Geopolis', which has strictly comparable figures for all towns and cities of the world over 10,000 inhabitants between 1950 and 1990. A Pareto model is used for identifying as metropolises one or a few large cities for each national urban system. From those data, two empirical power laws are established, linking the size of the metropolises to the size of their national urbansystem. The first is a transversal law: for a set of countries at a given date, the share of population concentrated in metropolises tends to decrease when larger countries are considered. The second law, which is longitudinal, shows that metropolises in the past have grown in a systematic way more rapidly than the rest of their urban system,invalidating Gibrat's urban growth model. Such empirical regularities could help for predicting the future of nowadays observed metropolisation trends. [ABSTRACT FROM AUTHOR]