Preface

Urbanization, i.e. the process whereby large number of people congregate and reside in big cities or in urban areas, gradually increases. Urban areas are generally characterized as relatively dense settlements of people and they are expanding as never before. Nowadays, more than 50% of the world's population lives in urban areas and demographic projections show that by 2025 the population growth of urban areas will constitute about 90% of all world population growth.

Urban areas are geographical points of problems and potentials. New economic dynamics, technological, social and cultural innovations occur and new opportunities appear. Additionally, social inequalities and environmental problems get worse in urban areas. In general, the increased urbanization creates both new opportunities or challenges and simultaneously new problems for human life. Thus, examining urban development, the planning and process by which urban areas grow is a challenge for contemporary life and it constitutes a scientific field where scientists originating from many fields are in contact and a lot of new issues are raised.

The main topics usually employed by Urban Development concern the following:


significantly influences the functioning of urban and global earth ecosystems and the services provided to urban people. Concerning urban environment, the most important inhabitant needs include, easy access to environmental infrastructure systems and services, availability of open urban spaces like parks and other green areas, provision of healthful housing. Furthermore, the most important adverse impacts on the urban environment affecting and caused by people are: water and air pollution, energy usage and wastage, solid and liquid waste management, land and ecosystem degradation, degradation of historic structures and cultural resources.


For a better understating of the conditions under which cities prosper and for a suggestion of policies by which positive urban development can occur, these issues should be studied. The chapters included in this book belong in the context created by the above issues.

I would like to thank all the authors for writing interesting chapters and spending time and effort in the preparation of this book. In addition, I would like to acknowledge Dr Marius Minea for reviewing two chapters. I believe that the book will be beneficial to the readers.

> **Dr. Serafeim Polyzos**  University of Thessaly, School of Engineering, Department of Planning and Regional Development, Volos, Greece

**Part 1** 

**Infrastructures and Urban Planning** 

**1** 

*1Makerere University* 

*2UNEP 1Uganda 2South Africa* 

**Reappraising Urban Planning** 

Shuaib Lwasa1 and Cecilia Kinuthia-Njenga2

**and Urban Sustainability in East Africa** 

In recent times, sustainable urban development has been a major challenge confronting the African region generally. This situation is further exacerbated by Africa's rapid urbanization at an average rate of 3.3 per cent per annum between 2000-2005. A rapidly urbanizing region, projected estimates indicate that by 2025 approximately half of the African population will be urban (UN-Habitat, 2008/9). This outstanding demographic shift on the African continent, and particularly Eastern Africa, presents current and future challenges for urban and regional planning (Lwasa, 2008; Rakodi, 1997). Furthermore, according to the UN-Habitat State of the World's Cities Report, 2006/7, rapid urbanization in Africa has occurred in the absence of a stable economic base though recent economic experiences show averagely high GPD rates for various countries. With chronic poverty widely prevalent, urbanization and slum formation are inextricably linked (UN-Habitat, 2007). Compounding this situation current statistics indicate that slums grew at a rate of 4.53 per cent per annum while overall urban growth rates were 4.58 per cent in the same period (UN-Habitat,

Africa urbanism is increasingly characterized by endemic poverty levels, fragmentation of the formal economy, weak institutions, declining employment and non-existent or deteriorating service provision (Clarke, 1995; UN-Habitat, 2009). But African urbanism also presents unique positive aspects and processes of urban space definition, use and spatial development patterns in which individual ingenuity for survival innovatively utilizes urban space in a productive way. These two strands of African urbanism present opportunities but also have created daunting challenges for sustainable urban development. Sustainable urban development in Africa and East African which would ensure social service provision, sustainable economic development, housing delivery, good urban governance, guided spatial development and urban environmental management. More recently urban development is challenged by mitigation and adaptation to climate change (Lwasa, 2008; Rakodi, 1997). The urban sustainability question in East Africa will require well designed pathways for urban development. This also raises the critical question of whether existing theories, models and practices of urban development offer solutions to the development and planning needs in the

2008/9) almost leveling the urban growth is thus synonym to slum growth.

African continent and Eastern Africa in particular (Lwasa, 2008; Akatch, 1995).

**1. Introduction** 
