PhD theses that contributed to GeoDiverCity programme


phd-swerts

Swerts E., 2013, The Indian and Chinese Systems of Cities , University Paris I.

Abstract. This thesis compares the urban systems in China and India using dedicated data bases that have been constructed using comparable and harmonized principles, describing the evolution of the population of all urban agglomerations above 10 000 inhabitants, every ten years from the beginning of 20th century for India and 1964 for China. Both very large countries of ancient urbanization are characterized by many small towns and have developed gigantic metropolises during the last decades. Despite their geo-historical specific features, these two systems share with others in the world the same properties of hierarchical differentiation and urban growth processes (Zipf’s law and Gibrat’s model), at country scale as well as for regional subsystems. A regional diversity is linked to former processes of unequal concentration of urban development. The most interesting result is identifying for the first time a reverse trend in the evolution of the Chinese urban hierarchy compared to other countries in the world among which India: despite the very rapid recent urban growth, the inequalities in city sizes are decreasing. This may in part depend of the under-registration of migrant urban populations. It also reveals the power of the political control on China’s urban processes that also appears in the magnitude of spatial concentration of manufacturing cities due to the implantation of Special economic Zones. Comparing the trajectories of Indian and Chinese cities may well improve the prospect of global urbanization that is crucial for the world and the planet.

Key-words. System of cities, Urban hierarchy, Zipf, Gibrat, Urban trajectories, China, India.

Link. HAL-SHS.



PhD Clémentine Cottineau

Cottineau C., 2014, The evolution of cities in the post-Soviet Space. Observation and modellings, University Paris I.

Abstract. The Russian and Soviet urbanisation process happened late and fast, compared to other territories. Many new towns and cities were created by the Soviet regime that officially promoted discourses about the socialist function of the city, rational organisation of space and a planned management of the economy. These urban particularities and the multiple demographic and political events of the 20th century have made cities in the post-Soviet space an interesting case and raised question regarding its ruptures and comparability. This dissertation thesis aims to show that the concept of system of cities and generic methods in urban geography (especially models) are useful in the study of urban evolution over the long term in this space, to eventually better understand past trends and predict future ones. We confronted several statistical models with the observed urban dynamics and concluded that the macro-geographical structure of cities in the post-Soviet space was comparable to that of other systems of cities (hierarchy of sizes, spacing, functional differentiation). We also observed specific trajectories related to the size of the territory, natural resources, the recent demographic shrinkage and the effect of particular political decisions. This knowledge about observed evolutions has been included in an incremental approach of agent-based modeling. Starting from theoretical hypotheses about generative mechanisms, we tried to generate generic and specific stylised facts, with a model as parsimonious as possible. The progressive evaluation of increasingly complex models led to the satisfactory simulation of observed urban evolution and highlighted specific trajectories that “resist” modeling.

Key-words. System of cities, Post-Soviet Space, Soviet Union, Generic/Specific, Simulation, Urban evolution, Urban growth.

Link. HAL-SHS.



PhD Clara Schmitt

Schmitt C., 2014, Modeling settlements systems dynamics : from SimpopLocal to SimpopNet, University Paris I.

Abstract. Is urban growth the result of multiple interactions between cities ? Urban evolutionary theory (Pumain, 2000), based on this postulate, analyses urban growth processes. This thesis, undertaken in an inter-disciplinary context, aims to evaluate the validity of the hypothesis by means of computer simulation. Strong regularities of the urban systems dynamics are extracted from the accumulated scientific knowledge and synthetized into ten major stylized facts. Two simulation models, SimpopLocal and SimpopNet, are then built, documented – thanks to a standardized grid – and systematically explored. They each question a specific aspect of the urban evolutionary theory : the nature of the inter-urban interactions for the first model (i.e. competition for innovation) and their support for the second model (i.e. the role of the communication network structure). The evaluation of the two models required the design and the implementation of two original exploration protocols : an automated calibration method and a sensibility analysis protocol (the Exploration Profile algorithm) which individually evaluates the contribution of each implemented mechanism to the simulated behavior. These two forms of exploration systematically confront the simulation results with current scientific knowledge. They indicate that the two models are able to account for key processes of urban systems dynamics, such as their hierarchical organization, and demonstrate for the first time the need for interurban interaction mechanisms in order to simulate urban evolutions that are close to those observed on real urban systems.

Key-words. System of cities, Urban systems, Simpop, SimpopLocal, SimpopNet, Simulation, Urban evolution, Urban growth.

Link. HAL-SHS.


Phd Ignazzi

Ignazzi C. A., 2015, Coevolution in the Brazilian Urban System, University Paris I.

Abstract. This thesis analyzes the urban system in Brazil adopting an advanced database that have been constructed collecting demographic data in order to examine the evolution of the population of all Brazilian agglomerations since the first Brazilian official census carried out in 1872 until 2010.
The largest country of South America has already completed its urban transition during the last century and is characterized by the contrast between a larger number of small towns throughout the immense territory and enormous Metropolitan areas dominating the system of cities.
Despite its geographical and historical peculiarities, this system shares with others in the world the same properties of hierarchical differentiation and urban growth processes (Zipf’s law and Gibrat’s model).
Economic data have been integrated in the database with the aim of testing the validity of scaling laws for Brazil and performing robust statistical analysis in order to explore the functional differentiation of cities, their economic performances and the spatial autocorrelation processes occurring among them.
The most interesting result is characterizing the Brazilian urban hierarchy over the long period and measuring the increasing inequalities in city sizes. Moreover, the parallel support of demographic and economic data is essential to identify the connection between population and economic growth in one of the most urbanized country of the world.

Key-words. System of cities, Urban systems, Urban hierarchy, Zipf, Gibrat, Urban trajectories, Brazil, Functional differentiation, spatial autocorrelation.

Link. Online.



PhD Rey-Coyrehourcq

Rey-Coyrehourcq S., 2015, An integrated platform for building and evaluating model of simulation in geography, University Paris I.

Abstract. Since 1990’s, Agent Based Modelling are commonly used by geographers to study complex systems like cities.
However, very few technical platforms are advanced by searchers to assist in the construction and evaluation of models of simulation. With the help of ERC program GeoDiverCity and the formation of an expert interdisciplinary team, we try to solve these problematic following two objectives. Relying on the support of OpenMOLE platform developed at the Institute of Complex System Paris-Ile-de-France in order to make it simple the distribution of simulation on distributed computing environments, we identify, use or build new tools and methodology to construct and explore model of simulation. To anchor this work in practice, we use this platform to build and explore a new model of simulation: SimpopLocal. This very practical work is accompanied by an historical and epistemological reading of simulation, and the means of simulation in geography. These contextualisation permits us to examine, and perhaps to anticipate, the historical link between the old problematic of “Validation”, very important to consider for knowledge justification, and the building and exploration of models of simulation.

Key-words. Simulation, Agent Based Modelling, Complex systems, Distributed computing environments, Validation.

Link. Online.



PhD Solène Baffi

Baffi S., 2015, Railways and city in territorialization processes in South Africa : from separation to integration?, University Paris I.

Abstract. First railway network in Africa, the South African Railways constitute a privileged marker of the territorial mutations that have been shaping this country for decades. The radicalism of political systems shows through the persistency of segregative schemes of which the railways, as part of the planning toolbox, are one of the elements. The inertia of this infrastructure questions its re-appropriation and insertion into the various planning projects over the long term. This thesis approaches the long-term dynamics of ‘territorialisation’ in South Africa through the prism of railways. This study focuses on the interaction between cities and the railway network, at both the interurban and the intra-urban levels.
In order to understand this interaction, cities’ location and railways diffusion patterns are analysed, with a specific emphasis on the shape of the network. Indeed, through their pattern, railways express the intentions of actors in charge of planning at the national level. By the flows it supports and the mobilities it enhances, it gives us information on the socioeconomic requirements of society and the power relations it contains. Thus, this thesis relies on a qualitative and quantitative approach aiming to outline the structuring effects of the railways in South Africa over the long term.
Its political use by successive segregationist powers explains partly why nowadays railways keep on marking partition in the post-apartheid urban space and in the practices of city dwellers. However, the recent rail renewal observed in the metropolises, Cape Town in particular, might indicate a possible major inflection in the persistency of inherited dynamics. Indeed, the evolution of the rail offer demonstrates a shift towards a co-construction trend between South African society and urban planning unheard of until now.

Key-words. System of cities, Urban system, South Africa, Railways, Territorialisation, Inclusion/exclusion, Intra-urban mobilities.

Link. HAL-SHS.



PhD Olivier Finance

Finance O., 2016, French cities hosting foreign direct investments: from networked companies to localized establishments, University Paris I.

Abstract. Transnational corporations, which are amongst the major players in the contemporary global economy, integrate and exclude territories at various scales, due to their specific location strategies. These inequalities are well known at an international scale, yet the knowledge of this diverse integration is much more limited regarding urban levels, although cities and metropolises are considered as being the major nodes of the globalized networks. France and the OECD countries certainly appear in central positions in the networks that characterize these corporations, but observations made at the urban level remain very partial due to the lack of localized data. This thesis suggests to both approach and localize conventional data about Foreign Direct Investment (FDI) in the French case by mobilizing data about financial links connecting economic units. The detailed breakdown of transnational corporations affiliation networks has been conducted up to the level of the establishments, which are the real individual economic and geographic cells of these transnational networks. An original database about localized inward FDI stocks has been built and explored to appreciate how far foreign transnational corporations integrate the 355 main cities into the French urban system. These data revealed the diverse integration of French cities, between dependence and attractiveness for the investors. The mobilization of scaling laws, which constituted a major analytical tool in this work, allowed us to identify the major factors explaining the diverse integration of French cities into the whole system of cities, reflected both by inequalities of hierarchical and regional order.

Key-words. System of cities, Urban system, France, Scaling laws, Foreign Direct Investment, Transnational firms.

Link. HAL-SHS.


How large are Chinese and Indian cities?

Reliable figures of cities’ population sizes are a great and useful by-product of comparative geographical analysis. We have identified which are now the major urban concentrations in the largest two countries of the world. Table 1 below provides the list of the population in top 30 Indian cities in 1981 and 2011 and top 30 Chinese cities in 1982 and 2010. In this table the last column on the right side enables comparing our results with figures that are given in official censuses of each country.

Table 1. Population of the 30 largest cities in India 1981 and 2011 and in China in 1982 and 2010Population 30 largest cities India ChinaSource: E. Swerts, 2013, for India : Indiacities database and Indian census; for ChinaCities database and Chinese Census

 

Towards mega-cities and megalopolises of a new kind

The multisecular Chinese and Indian urban development that intensified since the 1980’s fascinates the observers, largely because it has produced supersized cities, as Shanghai, Delhi and Beijing counting each around 20 million inhabitants. These cities are and will remain on the list of the 10 largest Urban Agglomerations in the World. They do not yet reach the size of formerly developed urban concentrations around Tokyo (38 millions in 2015 according to the United Nations, 43 according to PopulationData.net) or even New York (19 millions in 2015 according to the United Nations, 23 according to PopulationData.net ) but due to their growth rate it is very likely that during the next decades, gigantic conurbations will organize around them: in China three megalopolises are already forming between Beijing and Tianjin, from Shanghai to Nanjing and between Guangzhou and Hong-Kong (including Shenzhen, Dongguan and Zhuhai) (figure 1). In India, the same could occur around Delhi and Kolkata, and from Mumbai to Pune (figure 2). In Kerala the deviations between our database and the census in tentative sizing the agglomerations of Kochi or Thiruvananthapuram reflects the very peculiar expansion of urbanization in that region, which tend to mix very dense urban and rural areas in a way slightly different from Indonesian or Chinese “desakota” (McGee, 1991).

Figure 1. The 30 Largest Cities in China in 201030 largest cities ChinaSource: Chinacities database, E. Swerts (2013)

 

Figure 2. The 30 Largest Cities in India in 201130 largest cities IndiaSource: Indiacities database, E. Swerts (2013)

 

Safer data for research as well

Gigantic efforts have been made by many authors for establishing safer figures on the size of urban agglomerations in a comparable way and avoiding big mistakes as in papers electing Chongqing as the largest “city” in the world. Chongqing was supposed to reach from 32 to 34 million of inhabitants 1 because of a confusion in translating the Chinese word for “municipality” that may indeed denote a “province” (in that case covering 82 300 km2, approximately the size of Austria!) whereas the population of the agglomeration, although already large enough, oscillate between 7 or 10 millions according to different sources.

Of course for comparing cities and assessing dynamic urbanization processes building data base where the size of cities is comparable in time and space is absolutely necessary and this step of the work was duly accomplished in GeoDiverCity’s work, for Europe (Rozenblat, 1992; Guerois et al. 2009), Former Soviet Union (Cottineau, 2014), India (Swerts, 2013), China (Swerts, 2013), United States (Bretagnolle et al., 2015), Brazil (Ignazzi, 2015) and South Africa (Baffi, 2016, Vacchiani-Marcuzzo, 2005). All these data bases will be made freely accessible in due time, including detailed information about their methodology and metadata. The methodology employed by Elfie Swerts for building the data bases on India and China is made explicit in the annex in the full post.

Elfie Swerts


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Singularities of urban systems in China and India

We show for the first time comparable and exhaustive maps of cities for the largest two countries of the world 1. Around year 2000 there represent the precise location of about 11 000 cities above 10 000 inhabitants in China and 7000 in India, regrouping respectively 690 and 380 million of urban citizens (figure 1 and 2).

Two subcontinents of megacities and small towns

A major singularity common to both urban systems when compared to the rest of the world is the combination of huge metropolises with a high density of numerous smaller towns. Each country has at least three megacities above 10 million inhabitants (Shanghai, Beijing, Guanzhou, Delhi, Mumbai, Kolkata) and Shanghai and Delhi are even each above 20 million. No doubt that in the next decades more very large urban centers will emerge, many of the largest cities of the world will be found in Asia and even a handful of gigantic conurbations called “megalopolis”.

But the distinctive feature of these urban systems is their dense underlying pattern of small towns with population between 10 000 and 50 000 inhabitants, of which there are almost 9 000 in China and 5 400 in India. One third of the urban population of each country lives in these relatively small settlements (whereas the proportion is only 25% in Europe and 5% in the United States of America). These small settlements are disseminated in every region, according to a rather more regular spatial pattern in India compared to the asymmetry between sporadic Western and denser Eastern urbanization in China (due to environmental and historical factors).

Figure 1 Population sizes of urban agglomerations in China (year 2000)

Source : Swerts Chinacities, urban agglomerations above 10 000 inhabitants

Figure 2 Population sizes of urban agglomerations in India (year 2001)

Source : Swerts, Indiapolis and IndiaCensus, urban agglomerations above 10 000 inhabitants

Two different types of urban hierarchies

Even if both countries share with all other urban systems a strong differentiation of city sizes according to a Zipf’s distribution, China appears as an exception in the world. Although the share of urban population is higher in China (urbanization rate = 60% against 40% only in India) the index which measures the level of inequalities of city sizes in the system (that is the slope of the adjusted rank-size curve) is only 0.8 in China (against 0.9 in India) (figure 3). Moreover, while the general trend in India, in conformity with observations in other parts of the world is an increase of these urban size differences during the historical urbanization process, the slope has been decreasing during the last forty years in China. That can certainly be explained by the strength of urban and spatial planning policies in this country – even if an uncertainty remains about the identification of urban population because of the hukou system. It is also a demonstration that an evolution toward more and more hierarchy in urban systems is not as inescapable as it may appear from uncontrolled urban dynamics in most world countries.

Figure 3 Rank-size distributions of cities in China and India around 2000

Sources : China : Swerts, ChinaCities (2000), India : Swerts, Indiapolis (2001)

Elfie Swerts


Notes:

  1.  Urban data bases have been built by Elfie Swerts from a variety of statistical and geographical sources according to a unified concept of urban agglomeration (continuously built up area).