"Based at the Harvard Graduate School of Design, the Urban Theory Lab (UTL) is a research team concerned to rethink the basic categories, methods and cartographies of urban theory in order to better understand and influence emergent forms of planetary urbanization.
In the early 1970s, Henri Lefebvre put forward the radical hypothesis of the complete urbanization of society.  This required, in his view, a radical shift from the analysis of urban form to the investigation of urbanization processes.  The Urban Theory Lab-GSD builds upon Lefebvre’s approach to investigate emergent sociospatial formations under early twenty-first century capitalism. 

Our research starts from the proposition that inherited frameworks of urban knowledge must be radically reinvented to illuminate emergent forms of twenty-first century urbanization. In contrast to the urban/suburban/rural distinction that has long underpinned the major traditions of urban research, data collection and cartographic practice, we argue that the urban today represents a worldwide condition in which all political-economic and socio-environmental relations are enmeshed, regardless of terrestrial location or morphological configuration. 
This emergent condition of planetary urbanization means, paradoxically, that even spaces that lie well beyond the traditional centers of agglomeration—from worldwide shipping lanes, transportation networks and communications infrastructures to resource extraction sites, alpine and coastal tourist enclaves, offshore financial centers, agro-industrial catchment zones, and erstwhile “natural” spaces such as the world’s oceans, deserts, jungles, mountain ranges, tundra and atmosphere—are becoming integral to a worldwide operational landscape for (capitalist) urbanization processes..."

Twitter:  UrbanTheoryLab
Facebook: urbantheorylab
Email:  utl@gsd.harvard.edu

Introducing The Urban Theory Lab
Neil Brenner - August 2013
Professor of Urban Theory and Director, Urban Theory Lab Harvard Graduate School of Design

"Contemporary urban research stands at a crossroads. As scholars struggle to decipher current forms of urbanization, they are forced to confront the limitations of inherited approaches to urban questions, to face the difficult challenge of inventing new theories, concepts and methods that are better equipped to illuminate emergent spatial conditions, their contradictions and their implications at diverse sites and scales around the world. The result of these efforts is an intellectual field in disarray."...

Only a preliminary framework is sketched in this report. The first part is theoretical study, trying to model urban-rural interlaced area (desakota) in China using multifractals dimension spectra. The second part is empirical analysis, and the object is to reveal the dynamic process of development and evolution of urban-rural interlaced area under the condition of exo-urbanization. The first part has been finished based on digital simulation, but the second part, the main body of this project, is still in progress

Chapters 1, 4 and 7 explore the idea of cities as sites of economic concentration and density. But a city is not a homogenous unit. This paper explores spatial inequalities within cities: how they are generated, what characteristics they have, and—similarly to inter-country, inter-territory and urban-rural inequalities—how these spatial inequalities become persistent and self-perpetuating, embodying serious economic and social problems. This conceptual frame views cities as agglomerations of ‘urban regions’—which exhibit significant spatial intra-urban inequalities, and where trends towards equality are constrained predominantly by labour immobility and land-use policies.

As of this year half of the world’s population is estimated to be living in cities1, therefore, an understanding of conflict and violence within an urban space is increasingly important. This paper’s output is an analytical framework, which examines the processes that lead from conflict to violence.
Defining violence as the manifestation of distorted power relationships produced by the complex interaction between risk factors, the paper assumes that it is the interaction of these risk factors, which creates the processes that lead to violent outcomes. Risk factors are viewed as existing conditions that could potentially culminate in violence. Based upon a threefold taxonomy of violence, rooted in existing literature, three exemplary cities were chosen and analysed. These cities are Nairobi, Kinshasa, and Bogota, which respectively typify economic, political, and social violence. The cases demonstrate coinciding and context specific processes, with three significant points of overlap being identified:
􀂃 The Primary Nexus: Is envisioned as the point where there is a significant alignment of common processes, and the point at which the potential for violence is extremely high. These processes are: a crisis of governance, unequal access to economic opportunity, economic decline, and the naturalisation of fear and insecurity.
􀂃 Secondary Nexuses: Are the points of overlap between two of the case cities, where the potential for violence is significant, but not as likely as in the primary nexus.
􀂃 Context Specific Processes: Highlight the unique manner in which risks factors interact to produce violence in each of the cities.

The Healthy Cities movement has been in process for almost 30 years, and the features needed to transform a city into a healthy one are becoming increasingly understood. What is less well understood, however, is how to deliver the potential health benefits and how to ensure that they reach all citizens in urban areas across the world. This task is becoming increasingly important because most of the world’s population already live in cities, and, with high rates of urbanisation, many millions more will soon do so in the coming decades.

The Commission met during November, 2009, to June, 2011, to provide an analysis of how health outcomes can be improved through modification of the physical fabric of towns and cities and to discuss the role that urban planning can have in the delivering of health improvements. The Commission began from the premise that cities are complex systems, with urban health outcomes dependent on many interactions and feedback loops, so that prediction within the planning process is fraught with diffi culties and unintended consequences are common.

Economic theories of systems of cities explain why production and consumption activities are concentrated in a number of urban areas of different sizes and industrial composition rather than uniformly distributed in space.
These theories have been successively influenced by four paradigms:
(i) conventional urban economics emphasizing the tension between economies due to the spatial concentration of activity and diseconomies arising from that concentration;
(ii) the theory of industrial organization as it relates to inter-industry linkages and to product differentiation;
(iii) the New Economic Geography which ignores land markets but emphasizes trade among cities, fixed agricultural hinterlands and the endogenous emergence of geography;
(iv) the theory of endogenous economic growth.
Among the issues examined are specialization versus diversification of cities in systems of cities, how city systems contribute to increasing returns in national and the global economies, the factors that determine skill distribution and income disparity between cities, the impacts of income disparity on welfare, whether population growth should cause economic activity to become more or less concentrated in urban areas, and how resources should be allocated efficiently in a system of cities. Related to the last issue, we consider models where cities are organized by local planners or developers as well as cities that self-organize by atomistic actions. A conclusion of the theoretical study of city systems is that markets fail in efficiently allocating resources across cities when certain intercity interactions are present and that a role for central planning may be necessary.

The urban age is upon us. For the first time in history, more people now live in cities than in the countryside. Virtually all world population growth for at least the next fifty years will be in cities, and the cities of the developing world will absorb most of this increase. This phenomenon should be viewed positively because there is general agreement that urbanization is fundamental to sustained national economic growth — indeed no country has achieved higher income status without greater urbanization. However, rapid urbanization is often an overwhelming management and financial challenge for developing country governments.
The increasingly concentrated poverty in urban slums is a consequence of urbanization. One billion people now live in slums in the developing world and that number is sure to increase. The promise and challenges of 21st century urbanization combine to offer an unprecedented opportunity to leverage U.S. foreign assistance in order to alleviate poverty and generate economic growth. To do so adequately, the U.S. will need a better foreign assistance structure with an increased urban development focus. Urban programs are a proven, effective, and efficient use of limited foreign assistance resources.

The report throws new light on current issues and challenges which national and local governments, the business sector and organised civil society are facing. On top of putting forward a number of recommendations, this report testifies to the wealth of good, innovative practice that countries of all sizes and development stages have accumulated across the region. It shows us that sustainable human settlements are within reach, and that cooperation between public authorities, the private and the voluntary sectors is the key to success. This report highlights a number of critical issues – demographic and economic trends, poverty and inequality, the environment, climate change and urban governance and management.

This title, State of China’s Cities, is a joint effort between UN-HABITAT, China Science Center of International Eurasian Academy of Sciences and China Association of Mayors. This report, covers five strategic steps to nurture and grow smarter cities. It aims to make easy access of international readers to the information about policies and practices that have engendered smart urbanization of China in the past 60 years. It also provides the experiences, lessons and challenges faced by China in sustaining its urban development in the context of rapid industrialization and urbanization within a globalizing world.

Unlike in most Latin American cities, street vendors organized in farmers’ markets popularly known as ferias libres in Santiago de Chile, gained legal recognition early in the twentieth century. Since then, comunas, or local municipalities, have provided vendors with individual licenses that stipulate the place and time of operations, and have defined a clear set of rules regarding customer service. However, this early legal recognition has not necessarily overcome the embedded conflict over the economic use of public space. As supermarkets become spatially positioned along the main streets within easy access of the city’s transportation system, feriantes, or licensed street vendors, are being relocated in less profitable areas. Moreover, coleros, or unlicensed vendors, are still flourishing despite efforts to restrict their numbers.

A growing number of cities around the world have established systems of monitoring the quality of urban life. Many of those systems combine objective and subjective information and attempt to cover a wide variety of topics. This paper introduces a simple method that takes advantage of both types of information and provides criteria to identify and rank the issues of potential importance for urban dwellers. The method combines the so-called ‘hedonic price’ and ‘life satisfaction’ approaches to value public goods. Pilot case results for six Latin American cities are summarized and policy applications are discussed.

This article surveys the problem of urban marginalization by one of its more critical expressions in the contemporary city: the slums. The aim is to define an urban design strategy for the integration of those settlements as part of the city context, which enables to find solutions for the conflict improving these communities quality of life.

This study focuses on the city of São Paulo, Brazil and examines the ways in which irregular and illegal growth have influenced the collective action of social movements of the urban poor. The study describes how São Paulo grew as a socially segregated city during the twentieth century due to calculated neglect on the part of the municipal authorities. Highlighting the city’s sociospatial inequality, degradation of the central districts and widespread irregularity, it illustrates how these factors have both negatively affected the urban poor and provided a catalyst for social mobilization.

Many commentators have noted the existence of a historical correlation between cities and democratization. This image of the city as an inherently civic space is linked to the notion that the spatial concentration intrinsic to urban contexts promotes a democracy of proximity. Seen from this perspective, it is perhaps not surprising that the most urbanized region of the global south, Latin America, is also a heartland of vibrant and much applauded democratic innovation. Of particular note are the myriad local level ‘radical democracy’ initiatives that have proliferated throughout the region’s cities during the past two decades. At the same time, however, it is a significant paradox that Latin American urban centres are also amongst the most segregated in the world, something that is widely considered to have a significantly fragmenting effect on public space, and is therefore undermining of democracy.

During the twentieth century, internal migration and urbanization shaped Brazil’s economic and social landscape. Cities grew tremendously, while immigration participated in the rapid urbanization process and the redistribution of poverty between rural and urban areas. In 1950, about a third of Brazil’s population lived in cities; this figure grew to approximately 80 per cent by the end of the nineteenth century. The Brazilian population redistributed unevenly—some dynamic regions became population magnets, and some neighbourhoods within cities became gateway clusters in which the effects of immigration proved particularly salient. This study asks, has domestic migration to cities been part of a healthy process of economic transition and mobility for the country and its households? Or has it been a perverse trap?

Some of DFID’s work to address urban poverty is impressive and is making a noticeable contribution towards meeting the Millennium Development Goal 7 target on slum upgrading. However, the Department needs to sharpen and refine its approaches to urban poverty. The last five years have seen rapid urbanisation, almost all of it within developing countries, yet DFID—along with other donors—has downgraded its support to urban development over this period. This process should be reversed.

The Department overwhelmingly focuses its efforts to address urban poverty in Asian, rather than African, countries. This balance needs to be redressed. Africa is the world’s fastest urbanising region and it has the highest proportion of slum dwellers. Without a new and comprehensive approach to urban development in Africa, a number of cities could face a humanitarian crisis in as little as five years’ time, given the huge expansion of their urban populations. Addressing urban poverty offers the opportunity to tackle wider development issues such as: unemployment and crime; social exclusion; population growth; and climate change and the environment.

Cities are central to achieving the Millennium Development Goals (MDGs), endorsed by the governments of the world at the United Nations on 8 September 2000.
This present compilation contributes to the MDGs by providing urban practioners with a wide range of experience, reflections and innovations.
The collection emphasises the dynamic nature of urban change and the value and potentials of sharing knowledge that contribute to processes of economic growth, social development, cultural diversity, environmental sustainability and the reduction of poverty.
Sikandar Hasan, Anna Soave, Khanh Tran-Thanh and Tina Simon - 2003, DPU

Since the beginning of time, the art and act of building has been at the core of human evolution and our relationship with the specific landscapes that surround us. And while the idea of building with traditionally local materials and resources still exists in parts of the world, in many western societies, the opportunity to initiate and engage in an actual building project is difficult in comparison to the amount of ideas that are hatched on a drawing board or computer.
Volume 1, October 2010: Wales Workshop: an exercise in local resource building practice

Globalization and market reforms have significantly facilitated urbanization of the population of the People’s Republic of China. This study assesses the structural and spatial redistribution of urban population and Chinese cities since the founding of the People’s Republic in 1949. Prior to the 1978 economic reforms, the system of cities created by the Maoist regime was dominated by large and extra-large cities because of the imperatives of optimal industrialization. For national defense considerations, most of the new cities were created in the central and western interior rather than the eastern coast. Market reforms and relaxation of state control over local development since the late 1970s have allowed a large number of small cities to flourish on the basis of bottom-up rural transformative development. The intrusion of global market forces has helped re-consolidate the dominance of the east coast in China’s urban development. Although small cities and towns have absorbed large number of rural migrants, large and extra-large cities have remained the most efficient and productive economic centers for capital investment and production. China’s urban development over the past five decades has been a direct outcome of state articulation and reconfiguration against different political and economic contexts. A superimposed dual-track system of urban settlements integrating the Maoist legacy of large city dominance at the top with the rapidly expanding component of small cities and towns at the bottom is quickly taking shape to characterize China’s urban development and urbanization.

This paper examines data on urbanization. We review the most commonly used data sources, and highlight the difficulties inherent in defining and measuring the size of urban versus rural populations. We show that differences in the measurement of urban populations across countries and over time are significant, and discuss the methods used to obtain these measurements, as well as those for projecting urbanization. We also analyze recent trends and patterns in urbanization. Finally, we describe the principal channels of urbanization and examine their relative contributions to the global urbanization process.

This paper examines the gendered nature of asset accumulation between 1978 and 2004 in Indio Guayas, a low-income community on the periphery of the city of Guayaquil, Ecuador. In so doing, it emphasizes both the importance of combining quantitative and qualitative intra-household data, as well as taking a longitudinal perspective rather than at a single point in time. This paper seeks to examine the relationship not only between gender and urban income poverty but also, more importantly, between gender and urban asset accumulation, illustrating how the combination of quantitative econometric measurement of assets and qualitative in-depth anthropological findings on the complex underlying gender relations both contribute to a far more comprehensive analysis of asset accumulation processes in urban contexts than can be gained from any single methodological approach.

This paper aims at understanding the dynamics of sectarian violence in the city of Beirut, by looking at the early phase of violence in the Lebanese civil war (1975–90), and the process of dividing Beirut into various sectarian enclaves controlled by the warring militias. The paper aims to show the way in which political actors used sectarian violence as a mechanism of social, political, and territorial control. As a point of departure, the paper views the city not only as a backdrop for conflict and violence, but also as an actual target. The objectives of the paper are threefold. First, it shows how sectarian violence was not random but was, rather, a product of a lengthy process that involved calculation and some levels of planning. It includes defining one’s neighbour as an enemy and as a threat. Second, it shows the measures and practices that were employed by militias to consolidate the full control of territory that entailed the transformation of space and place into homogenous entities. Third, it looks at the centrality of the concepts of homogenization of space (and place) and territoriality in the course of waging sectarian violence.

Dar es Salaam is exceptional in East Africa for having a record of relatively little ethnic tension, and remaining tranquil and true to its name, the ‘harbour of peace’. This paper explores the interface between ethnic and national identities in Tanzania’s capital city, focusing on its ethnic foundations and their malleability with regard to nationalism, asking how nationalist identities were negotiated vis-à-vis existing local ethnic identities. How willing were ethnic groups that were indigenous to the locality to ‘share’ the city, its land, and amenities with newcomer compatriots, given that the city was almost as new as the nation-state? How did their modus operandi affect nation-building?

As the world moves towards its so-called urban ‘tipping point’, urbanization in the global South has increasingly come to be portrayed as the portent of a dystopian future characterized by ever-mounting levels of anarchy and brutality. The association between cities, violence, and disorder is not new, however. In a classic article on ‘Urbanism as a way of life’, Louis Wirth (1938: 23) famously links cities to ‘personal disorganization, mental breakdown, suicide, delinquency, crime, corruption, and disorder’. He does so on the grounds that the urban context constituted a space that naturally generated particular forms of social organization and collective action as a result of three key attributes: population size, density, and heterogeneity. Large numbers lead to a segmentation of human relations, the pre-eminence of secondary over primary social contact, and a utilitarianization of interpersonal relationships. Density produces increased competition, accelerates specialization, and engenders glaring contrasts that accentuate social friction. Heterogeneity induces more ramified and differentiated forms of social stratification, heightened individual mobility, and increased social fluidity.
While large numbers, density, and heterogeneity can plausibly be considered universal features of cities, it is much less obvious that they necessarily lead to urban violence. This is a standpoint that is further reinforced by the fact that not all cities around the world – whether rapidly urbanizing or not – are violent, and taking off from Wirth’s characterization of the city, this paper therefore seeks to understand how and why under certain circumstances compact settlements of large numbers of heterogeneous individuals give rise to violence, while in others they don’t, focusing in particular on wider structural factors as seen through the specific lens of urban gang violence.

Since the 1980s, the promotion of heritage values has gradually become a relevant issue for urban planning. Together with the emergence of new peripheries, inner-city areas and particularly old historic centres, affected by deterioration due to the recession of the last decades, have been the object of study and actions. Consequently, the need to turn the historic centres into areas of development for the market, through legislative measures and investments in infrastructure and services, and the re-evaluation of the heritage value of existing buildings, oscillated between policies which, linked to the mechanisms of economic and cultural globalization, promoted tourism as a source of revenue while striving to find alternatives to gentrification. The renewed priority given to the development of inner-city areas, centred round the rehabilitation of their historic values and central nature, has generated innovative operating modes in the urban environment that seek to reconcile the challenges of modernity, particularly in regard to social inequalities with those of the past, and to rethink the central role of historic centres, their relations with the city and their development in terms of sustainability.
The goal of our contribution is to gain a better understanding of the major challenges of the rehabilitation of historic centres within the framework of ‘innovative’ approaches to urban planning, aiming at promoting sustainable living conditions. The analysis is based on an ongoing comparative and transdisciplinary research project, in which the decision-making processes of concrete interventions for the rehabilitation of inner-areas with heritage value are being analyzed in different cities of the world: Buenos Aires, La Havana and Bangkok. The main questions that arose in our analysis concern the contexts allowing for innovation, focusing on those institutional arrangements, which, as modes of governance, were introduced in the interventions, studied.

Do local improvements in infrastructure provision improve city competitiveness? What public finance mechanisms stimulate local infrastructure supply? And how do local efforts compare with national decisions of placing inter-regional trunk infrastructure? In this paper, we examine how the combination of local and national infrastructure supply improve city competitiveness, measured as the city’s share of national private investment. For the empirical analysis, we collect city-level data for India, and link private investment decisions to infrastructure provision. We find that a city’s proximity to international ports and highways connecting large domestic markets has the largest effect on its attractiveness for private investment. In comparison, the supply of local infrastructure services – such as municipal roads, street lighting, water supply, and drainage – enhance competitiveness, but their impacts are much smaller. Thus, while local efforts are important for competitiveness, they are less likely to be successful in cities distant from the country’s main trunk infrastructure. In terms of financing local infrastructure, we find that a city’s ability to raise its own source revenues by means of local taxes and user fees increases infrastructure supply, whereas as inter governmental transfers do not have statistically significant effects.

Many cities in Africa, Asia, and Latin America face serious problems managing their wastes. Two of the major problems are the insufficient collection and inappropriate final disposal of wastes. Despite spending increasing resources, many cities – particularly in Africa and Asia – collect less than half of the waste generated. Most wastes are disposed of in open dumps, deposited on vacant land, or burned by residents in their backyards. Insufficient collection and inadequate disposal generate significant pollution problems and risks to human health and the environment. Over one billion people living in lowincome communities and slums lack appropriate waste management services. Given the rapid population growth and urbanization in many cities, the management of wastes tends to further deteriorate.
This paper examines the challenges and opportunities that exist in improving the management of waste in Africa, Asia, and Latin America. It is argued that, despite a worsening trend, there are opportunities for reducing pollution, alleviating poverty, improving the urban environment, and lowering greenhouse gas emissions in developing countries by implementing low-cost, low-tech, labour-intensive methods that promote community participation and involve informal refuse collectors and waste-pickers. Evidence from several cities in Africa, Asia, and Latin America is discussed.

Population density gradients for South Africa’s cities are quite small in absolute value, indicating a relatively flat population distribution across the cities. In contrast employment is less flatly distributed than the population. The relationship between employment densities and distance across South African cities has remained constant between 1996 and 2001 whilst there has been on average a slight increase in population density further away from the city centres. As per capita income of the population rises, density in the central city areas decreases. Employment growth has no significant impact on suburbanization indicating that population settlement does not necessarily follow jobs. Finally, it is found that there have been decreases in segregation in South Africa’s metropolitan cities since 1996 especially in the former white group areas, which could suggest that the formerly spatially excluded black population is slowly moving into former white areas, which are also closer to where economic activities are located.

The paper presents a theoretical model that seeks to answer the question of why former squatter settlements tend to upgrade/redevelop at a slower pace than otherwise similar settlements originating in the formal sector. We argue that squatter settlers’ initial strategy to access urban land creates a ‘legacy effect’ that curtails settlement upgrading possibilities even after the settlements are granted property titles. We test our model using the case of Cochabamba, Bolivia and obtain results consistent with our theoretical model prediction. Our results suggest that the commonly used ‘benign neglect while keeping the threat of eviction’ policy has profound impacts on how land is developed in the informal sector and this poses costly consequences for local governments after legalization.

This paper describes the methodology of a longitudinal multi-generational study in the favelas (shantytowns) of Rio de Janeiro from 1968 to 2008. Major political transformations took place in Brazil during this interval: from dictatorship to ‘opening’ to democracy; major economic transformations from ‘miracle’ boom to hyperinflation and crisis, and to relative stability; and major policy changes from the removal of favelas to their upgrading and integration. However, despite the cumulative effects of these contextual changes, poverty programmes and community efforts, the favela population has continued to grow faster than the rest of the city and the number and size of the favelas has consistently increased over these decades.

A common challenge in analyzing urbanization is the data. The United Nations (UN) compiles information on urbanization (urban population and its share of total national population) that is reported by various countries but there is no standardized definition of ‘urban’, resulting in inconsistencies. This situation is particularly troublesome if one wishes to conduct a cross-country analysis or determine the aggregate urbanization status of the regions (such as Asia or Latin America) and the world. This paper proposes an alternative to the UN measure of urban concentration that we call an agglomeration index. It is based on three factors:
• Population density
• The population of a ‘large’ city centre
• Travel time to that large city centre.
The main objective in constructing this new measure is to provide a globally consistent definition of settlement concentration in order to conduct cross-country comparative and aggregated analyses. As an accessible measure of economic density, the agglomeration index lends itself to the study of concepts such as agglomeration rents in urban areas, the ‘thickness’ of a market, and the travel distance to such a market with many workers and consumers. With anticipated advances in remote sensing technology and geo-coded data analysis tools, the agglomeration index can be further refined to address some of the caveats currently associated with it.

One of the most visible and enduring manifestations of urban poverty in developing countries is the formation and proliferation of slums. While attention has focused on the rapid pace of urbanization as the sole or major factor explaining the proliferation of slums and squatter settlements in developing countries, there are other factors whose impacts are not known with much degree of certainty. It is also not clear how the effects of these factors vary across regions of the developing world. This paper accounts for differences in the prevalence of slums among developing countries using data drawn from the recent global assessment of slums undertaken by the United Nations Human Settlements Programme.
The empirical analysis identifies substantial inter-country variations in the incidence of slums both within and across the regions of Africa, Asia as well as, Latin America and the Caribbean. Further analysis indicates that higher GDP per capita, greater financial depth and increased investment in infrastructure will reduce the incidence of slums. Conversely, the external debt burden, inequality in the distribution of income, rapid urban growth and the exclusionary nature of the regulatory framework governing the provision planned residential land contribute positively to the prevalence of slums and squatter settlements.

Areas:
Mozambique, Tanzania, Kenya, Bangladesh, Benin, Mauritania, Senegal, Mali, Sudan, Nepal, Zimbabwe, Uganda, Zambia, Malawi
Topics:
Urban, Climate Change

"This report outlines lessons learnt regarding the principal effects of climate change on 15 cities
in low-income countries, and what makes them vulnerable to these effects. Coastal cities are susceptible to a rise in sea level and are made vulnerable by the low-lying land they are often built on, while dryland cities suffer from scarce water resources due to extended periods of climate change-induced drought. In these and other inland cities, the level of poverty, the rapid pace of urbanization and a lack of education about climate change increase vulnerability and aggravate the effects of climate change. Innovative urban policies and practices have shown that adaptation to some of these effects is possible and can be built into development plans. These include community-based initiatives led by organizations formed by the urban poor, and local governments working in partnership with their low-income populations".

Even though urban planning has changed relatively little in most countries since its emergence about one hundred years ago, a number of countries have adopted some innovative approaches in recent decades. These include: strategic spatial planning; use of spatial planning to integrate public sector functions and to inject a territorial dimension; new land regularization and management approaches; participatory processes and partnerships at the neighbourhood level; new forms of master planning that are bottom-up and oriented towards social justice; and planning aimed at producing new spatial forms such as compact cities and new urbanism.
However, in many developing countries, older forms of master planning have persisted. Here, the most obvious problem with this approach is that it has failed to accommodate the way of life of the majority of inhabitants in rapidly growing and largely poor and informal cities, and has often directly contributed to social and spatial marginalization. Urban planning systems in many parts of the world are still not equipped to deal with this and other urban challenges of the twenty-first century and, as such, need to be reformed.

Kenya’s slums are growing at an unprecedented rate as more and more people move to Kenya’s cities and towns in search of employment and other opportunities urban areas offer. The government and local authorities are faced with the serious challenge of guiding the physical growth of urban areas and providing adequate services for the growing urban population. Kenya’s urban population is at present 40 percent of the total population. More than 70 percent of these urbanites live in slums, with limited access to water and sanitation, housing, and secure tenure. They have poor environmental conditions and experience high crime rates. If the gap continues to grow between the supply and demand of urban services such as housing, the negative consequences of urbanisation can become irreversible.