This entry will deal with urbanisation is from the view of UN Habitat and all numbers come from them.
4 billion people (54% of people) live in urban areas. Of those 1 billion live in Informal Settlements (or slums) where basic services and tenure security are lacking. However, cities account for 80% of GDP. Urbanisation is related to economic development, but also to inequality and exclusion which drive safety and security concerns. Additionally, city account for 70% of the CO2 emissions and therefore can be considered a main cause of climate change.
Previous/current urbanisation has been unsustainable in terms of environment, society and economy.
- Environmentally, suburbanisation sprawls over land and destroy ecosystems
- Socially, inequality, exclusion, and deprivation form spatial inequality and divided cities
- Economically, unemployment , low-paying jobs and informal income cause hardship and poor quality of life
To reach sustainability the following issues must be tackled:
- Continuous growth of slums: Caused by a lack of housing policies. Slums are vulnerable to natural and man-made disasters. Often slum dwellers are semi-legal have no (government) services and lack utilities (water, electricity and waste disposal). Lack of tenure security creates a state of temporary accommodation
- Provision of urban services: Includes transport, water, sanitation, electricity health, education, maintenance of public space, lighting, cemeteries, etc.
- Climate change: Climate events could damage urban areas , but also drive people from endangered areas to urban areas (rural-urban migration)
- Inequality and exclusion: The gab between the rich and the poor is increasing, this in turn leads to increased crime, gated communities, privatisation and segmentation of urban space, segregation
- Upsurge in involuntary migration: Forced migration is changing urbanisation, people are displaced into neighbouring countries, requires innovative housing solutions, often stay after cause for migration is resolved, can be a breeding ground for frustration and radicalisation
- Rising insecurity and urban risks: Terrorism, urban warfare, disease and pandemics are major risks, but also fear of crime and violence. This may cause brain-drain and hinder economic development
A preview of the course Urban Design I given at D-ARCH at ETH.
Apartheid is not only South African, but a general construction pattern in cities used to keep cheap labour close to Middle- and Upper-class housing. It can be seen in São Paulo, Caracas and Johannesburg.
Urban terror has replace rural terror (e.g. how it happened in Colombia) from revolutionaries to extremists to criminals.
Natural catastrophes haunt urban environment and are often unaccounted for because they mostly hit the informal settlements.
Social housing plans like 23s de Enero in Caracas provided infrastructure that would later help barrios (slums) to grow in the in-between spaces creating a functioning environments (compared to other social housing plans that failed horribly).
Transportation systems are often unique and transplanting them is difficult. The important part is to be able to describe the essential units of the system and find places where such a system could be of advantage. An example are cable-cars in the mountainous slums of Latin America (Caracas, La Paz, etc.). The cable-car stations where used as bases to create additional services (post services, ATMs, etc) in a secured area. Cable-car masts can be used to host wind farms (not a 3-rotor design).
Skyscrapers are an interesting environment. Elevators are a reason why skyscrapers are not interconnected on higher levels. Elevators are stopping at each floor though through design elevators could only stop at every few floors with ramps connecting the intermediate floors.
More can be found in the Urban Toolbox.
“There is not an ideal world, but we can improve upon the current state.” – Hubert Klump
Latent challenges are often ignored like air pollution in cities (in South Asia and elsewhere), no drinking water from the tab (like Manilla in the Philippines) or homicides per day (in Caracas more people are murdered per year than die in the Syrian civil war without mentioning). Latent problems are so permanent that often they are overlooked.
Tenure: The process of acquiring land to live on.
In the developed word generally, lad is bought, its development is planed, it is build upon and then people move in.
In many parts of the developing world tenure is not existent. Therefore people squat land. If they are not forced out they start building. The building is slowly and iteratively extended as there is no security for the ownership of the building.