Intermediate Cities | EPFL Graph Search

Cities are defined mainly based on spatial and demographic criteria. The criteria of intermediation helps in identifying current urban dynamics, in relation to surrounding suburban/rural areas or in national and international environments. Medium‐sized cities are emblematic of so‐called “intermediate cities.” According to international thresholds, nearly 50 percent of the world's urban population now live in cities of less than 500,000 inhabitants. In developing countries, these cities face particular difficulties: less efficient public administration, insufficient funds to meet social needs, and lack of skilled individuals to manage large projects. In more industrially and technologically advanced countries, intermediate cities long suffered from the primacy of larger‐sized cities. An intermediate city is defined based on a certain number of characteristics, with three spheres of influence: the micro regional scale, the national scale, and the international scale. Three positions for these cities can be identified: “affected” intermediate cities, with a strong position in their territory; “satellite” intermediate cities, near larger cities; and “remote” intermediate cities, distinguished by a more closed system vis‐à‐vis the outside, given their remoteness. Because of their characteristics, intermediate cities should be the target of regional planning to link urban growth and territorial balance between city and country.

Métropolisation, habitat précaire et relogement forcé: entre phénomènes d'exclusion et tactiques populaires d'intégration

Sébastien Wust

This work was carried out within the interdisciplinary scientific program named "Sustainable Development, Metropolisation and Pollution of Natural Resources in Ho Chi Minh-City, Vietnam". This program, launched in 1994, is financed by the Swiss National Science Foundation (Priority Program Environment, Module 7 "Environment and development"). The main goal of this thesis is to grasp the social, economic and spatial dimensions at stake of involuntary resettlement of precarious settlements. in the context of developing countries' metropolisation. One of the approach selected fits within a thorough study of southern metropolis evolution dynamics, more precisely that of disadvantaged neighbourhoods. Moreover, we decided to develop a specific approach of involuntary resettlement, which is constructed using mainly two dialectical and interdependent concepts: exclusion and integration. In this way, this work differs from the most frequently used theoretical models, which are based on impoverishment or stress dimensions. In third world metropolis, government forces have an increasing tendency to turn to involuntary resettlement in order to implement or promote urban planning. Every year, approximately 6 million people are forced to move into an urban environment. This concerns mainly the most underprivileged sections of the population corning from precarious settlements. In recent times, this phenomenon has grown to such a point that some international institutions have even talked about the century of involuntary resettlement. The theoretical framework of this thesis refers to three different fields of knowledge, which nevertheless are linked to one another. The first field concerns developing countries metropolisation. Closely associated with the globalisation and polarisation of international trade, this process leads not only to the rise of exclusion but also to the dualisation of economic, social and political spheres and the fragmentation of urban spaces. The second theoretical field of study is based on questions raised by precarious settlements in southern metropolis. We analyse the way vulnerable populations living in disadvantaged neighbourhoods develop urban integration tactics in order to counter metropolitan exclusion forces and to alleviate precariousness. Finally, the third field is part of involuntary resettlement problematic. While it shares a close link to public policy evaluation, this problematic analyses the institutional values, norms, and practices underlying relocation policies of the people living in disadvantaged neighbourhoods. Our goal is also to develop a better understanding of the consequences associated to this kind of urban program and the way they might contribute to strengthening living conditions as well as residential situation precariousness for those who have been forced to move, leading them to develop defence mechanisms in order to guaranty their integration in the metropolis. In this analysis, we will focus on Ho Chi Minh-City and on the relocation program concerning the populations living in Nhieu Loc-Thi Nghe canal's precarious settlements. In the empirical part of this work, we will analyse and measure the consequences of this policy on their living conditions as well as on their behaviour. We will try to analyse to what extent those consequences tend to increase exclusion of underprivileged populations, limit their integration capacity, and enhances their residential mobility towards new precarious settlements that fit more to the aspirations, and above all, to the means of the underprivileged. Given the complexity of the topic covered in this work, we opted for an interdisciplinary approach. It appeals to different fields of social sciences: sociology, economics, geography, political sciences, but also architecture and urban planning. Moreover, we chose a quantitative as well as a qualitative method. Based on a multidimensional analysis of Nhieu Loc-Thi Nghe canal's population living in precarious settlements, we will be able to grasp the discriminating dimension of involuntary resettlement policy set up by metropolitan authorities as well as its severe impact on the population at a residential, social and economical level. Restrictive economic criteria or in some cases insufficient compensations offered by public authorities are such that a number of persons are excluded from the program. But on top of that, part of the families relocated in modern and salubrious apartments suffer from exclusion. As regards housing, the new apartments are characterised by their limited residential functions. This is mainly due to constraints linked to high rise housing, which acts as an economic and social barrier. In terms of social organisation, involuntary resettlement leads to a family nuclearisation process, and traditional sociability tends to turn to a more individualistic way of life, a phenomenon which results in a partial deconstruction of solidarity and protection networks. Finally, at the domestic economy level, resettled populations have to deal with an increase in service charges as well as working conditions deterioration which involve decreasing incomes. Although this modern way of life appeals to resettled families, most of them are brought to develop new integration tactics in order to limit involuntary resettlement exclusion effects. These tactics are to a large extent conservative inasmuch as they tend to reproduce ways of life and space habits characteristic of the former residential areas. To a large extent, they are characterised by palliative measures of space utilisation, professional insertion, income improvement and domestic means reallocation. Despite their willingness, families have a hard time fighting against resettlement exclusion forces. Residential mobility as well as subsidised apartments resale then become the way for some families to minimise precarious living conditions. Nevertheless, the benefits they gain from these illegal practices are often insufficient for them to buy or build an accommodation close to the center of the metropolis. The only possibility left to the reseller is then to rent a dwelling unit in a disadvantaged neighbourhoods or to move on the outskirts. While residential mobility leads to the creation of new precarious settlements in Ho Chi Minh-City, some families living conditions as well as residential situation keep on deteriorating, a decline which might bring some of them to experience a kind of urban nomadism. While the results of our study confirm the hypothesis stated at the beginning of this work, they also point out how hard it is to fulfill the housing aspirations of the most underprivileged considering the precariousness of their living conditions. The inadequacy of precarious settlements relocation policy is even worse when based on a modernist and standardised approach of the housing problem which favours typological and technical dimensions of residential space to the detriment of social, economic and ecological dimensions. What is at stake in involuntary resettlement concerns mainly the multidimensional mechanisms of exclusion and integration of which depends the subsistence of the most underprivileged in Ho Chi Minh-City. Urban authorities need to make political adjustments if they want resettlement impacts to fit the goals of sustainable development. In order to achieve this objective, popular participation and exchange between involved actors is the first condition they need to fulfill for the implementation of any policy in order to fight against exclusion and promote the integration of the most underprivileged as well as for any policy which aims to take into account the capacity of urban ecosystems.

EPFL2001

Méthodologie de gestion durable des ressources du sous-sol urbain

Pascal Blunier

The world is becoming more and more urban. During the last fifty years, the population in Swiss cities has grown from 45% to 70% of the total population. This change is characterised by urban sprawl and by an increase in the consumption of resources, particularly those coming from rural areas. This evolution is not compatible with the principles of sustainable development. To solve this problem, new urban policies are being developed. They favour development within the urbanised areas and reduced use of exogenous resources. The urban underground contains resources – space, geomaterials, groundwater and geothermal energy – which can efficiently support such policies. This project analyses how these resources have been exploited until now and how they could be used with sustainability in mind. The use of underground resources was analysed in five cities : Mexico, Paris, Helsinki, Tokyo and Montreal. It appears that, although resources participate in the urban metabolism, there is an important lack of planning and coordination in their use. Developments follow a sectional approach where the resources are considered independently, and only at the scale of a given construction project. As a consequence, conflicts occur between uses and resources are wasted. An understanding of the urban underground as a system was developed with the aim of preventing conflicts and promoting synergies. To this effect, the way in which resources interact was considered attentively. Situations in which interactions occur were described and analysed and compatibility conditions were suggested. A methodology was elaborated to evaluate the resource potential of an urban underground. It aims at considering the resources and the interactions between their uses from the beginning of the process of urban planning. The methodology is based on the use of Geographical Information Systems and 3-D modelling of geological and hydrogeological conditions. It aims at reversing the current paradigm, that proceeds from the needs to the resources, into an approach based on resources to satisfy the needs. Spatial information was exploited to determine indicators and maps of potentiality and of restrictions. The derived results will help support decision making by planners and policy makers who seek to better exploit the resources from the urban underground. The methodology was tested and applied on a case study : Geneva. The developed approach allows more efficiency in the use of urban underground resources, it can help prevent conflicts between uses and develop synergies. When integrated in the urban planning process, it highlights new opportunities and helps to develop projects that take into account the physical conditions of the underground.

EPFL2009

Conception et évaluation d'un prototype de simulation de la morphogenèse urbaine par agents vecteurs multi-échelles

Vitor Silva

The research work of this PhD thesis was carried out in the context of an interdisciplinary project related to the study of urban morphogenesis. A team composed of architects and engineers specialized in GIS technologies have worked together in this project during three years, sharing their knowledge in order to understand and simulate the evolution of the urban environment of cities. The fundamental hypothesis that conducted this research is that the city can be seen as a self-organizing system governed by a set of morphogenesis rules, which can for example, determine the location of new architectural programs and induce the city's organization, from local to global scales. Architectural programs themselves are supposed to determine city's development. In this PhD thesis a simulation prototype of the urban growth based on the use of multi-agents systems was carried out. This prototype is a computer tool that allows the analysis and representation of the growth of the built environment. Nowadays, the ability to understand and simulate urban evolution proves to be essential in order to control the evolution of a city in a sustainable development view. Furthermore, this tool should facilitate the understanding and decision-making of those concerned with problems related to urban development. The urban system has been modeled as a set of space objects, such as buildings and networks, which interact between themselves. These interactions are carried out at different levels, from local to global scales, being controlled by behavioral rules or laws of growth. The result of their interaction can be figures or emergent phenomena represented at several scales. The approach using multi-agents vector systems was chosen in order to model a geographical complex system like a city, which integrates a vectorial modeling of space. Hence, each spatial agent does not possess a limit of form and size. The interest of using multi-agents vector systems also lies in their ability to manage various models of individuals, from simple entities to more complex ones. Thus, various levels of representation, such as individuals and groups of individuals, can be managed, which is not easily feasible, for example, with cellular agents. The development platform used is GeOxygene (Java computer programming language), which is an open-source platform developed at IGN (Institut Géographique National, France), by COGIT laboratory. This platform provides several GIS functions, allowing the development and implementation of the prototype here presented. An interaction model between agents was defined and the type of scenarios of each of these interactions was detailed. A set of methods and associated classes was developed. Agent's architecture was conceived in order to allow manipulation (sending, receiving and treatment) of exchanged messages. In order to show the relevance of the multi-agent multi-scale methodology, examples of buildings creation in a case study zone were carried out. Using the multi-scale vector simulation prototype here presented, the development of cities can be computed in a very innovative way. However, the developed prototype still lacks some accuracy, mostly due to the fact that the specified laws adopted for simulation do not reflect the whole reality, which is obviously much more complex to traduce. We have not yet validated the model for other cities – nevertheless, the model could already be used as a decision support tool, particularly as a planning support instrument for architects and urban planners. With regards to future work this prototype shall be integrated in a global approach of urban simulation, allowing the analysis of environmental risks, demographic and economic growth and transports simulation at different scales of analysis and 2D/3D visualization output, such as district and city.

EPFL2010