Urbanization: Some Key Terms and Definition

URBAN GROWTH

The (relative or absolute) increase in the number of people who live in towns and cities. The pace or urban population growth depends on the natural increase of the urban population and the population gained by urban areas through both net rural-urban migration and the reclassification of rural settlements into cities and towns.

 

URBANIZATION

–  The portion of a country that is urban

–  Changes in the proportion of the population of a nation living in urban places (demographics)

–  Process of people moving to cities or other densely settled areas

–  Changes in social organization resulting from population concentration

–  In other words, the process by which rural areas are transformed into urban areas

 

RATE OF URBANIZATION

–  The increase in the proportion of urban population over time, calculated as the rate of growth of the urban population minus that of the total population. Positive rates of urbanization result when the urban population grows at a faster rate than the total population.

–   

CITY PROPER

–  The population living within the administrative boundaries of a city

 

URBAN AGGLOMERATION

–  The population of a built-up or densely populated area containing the city proper, suburbs and continuously settled commuter areas or adjoining territory inhabited at urban levels or residential density

 

METROPOLITAN AREA/REGION

–  A formal local government area comprising the urban area as a whole and its primary commuter areas, typically formed around a city with a large concentration of people (i.e a population of at least 100,000)

–  In addition to the city proper, a metropolitan area includes both the surrounding territory with urban levels of residential density and some additional lower-density areas that are adjacent to and linked to the city (e.g., through frequent transport, road linkages or commuting facilities). Example of metropolitan areas include Greater London and Metro Manila.

 

URBAN SPRAWL

–  Also “horizontal spreading” or “dispersed urbanization”. The uncontrolled and disproportionate expansion of an urban area into the surrounding countryside, forming low-density, poorly planned patterns of development.

–  Common in both high-income and low-income countries, urban sprawl is characterized by a scattered population living in a separate residential areas, with long blocks and poor access, often over dependent on motorized transport and missing well defined hubs of commercial activity.

 

PERI-URBAN AREA

–  An area between consolidated urban and rural regions

 

MEGACITY

–  An urban agglomeration with a population of 10 million or more.

 

METACITY

–  A major conurbation- a megacity of more than 20 million people. As cities grow and merge, new urban configurations are formed. These include mega regions, urban corridors and city regions.

 

MEGAREGION

–  A rapidly growing urban cluster surrounded by low density hinterland, formed as a result of expansion, growth and geographical convergence of more than one metropolitan area and other agglomerations. Common in North America and Europe, mega-regions are now expanding in other parts of the world and are characterized by rapidly growing cities, great concentrations of people (including skilled workers), large markets and significant economic innovation and potential.

–  Examples include the Hong Kong-Shenzhen-Guangzhou megaregion (120 million people) in China and the Tokyo-Nagoya-Osaka-Kyoto-Kobe mega-region (predicted to reach 60 million by 2015) in Japan.

 

URBAN CORRIDOR

–  A linear ‘ribbon’ system of urban organization: cities of various sizes linked through transportation and economic axes, often running between major cities. Urban corridors spark business and change the nature and function of individual towns and cities, promoting regional economic growth but also often reinforcing urban primacy and unbalanced regional development.

–  Examples include the industrial corridor developing between Mumbai and Delhi in India; the manufacturing and service industry corridor running from Kuala Lumpur, Malaysia, to the port city of Klang; and the regional economic axis forming the greater Ibadan-Lagos-Accra urban corridor in West Africa

 

CITY-REGION

–  An urban development on a massive scale: a major city that expands beyond administrative boundaries to engulf small cities, towns and semi-urban and rural hinterlands, sometimes expanding sufficiently to merge with other cities, forming large conurbations that eventually become city-regions.

–  For example, the Cape Town city-region in South Africa extends up to 100 kilometers, including the distances that commuters travel every day. The extended Bangkok region in Thailand is expected to expand another 200 kilometers from its center by 2020, growing far beyond its current population of over 17 million.

 

References: UPOU PPT Lecture

Approaches in Spatial Analysis

 

In his doctoral thesis titled Spatial Analysis in Support of Physical Planning (2003),  Eric Koomen emphasizes the important role of spatial analysis in the formulation and evaluation of physical planning initiatives. To carry out this role, one must be knowledgeable about the application of different approaches in spatial analysis in such a way that it will correspond or will respond to the planning issues at hand.

 

Koomen enumerates these spatial analysis approaches as follows:

 

1.    Transformation

Transformation methods form the basis of data visualisation and essentially change a certain form of data representation into another to enhance specific features.

 

Two commonly applied transformation methods are: classification and filtering.

 

Classification is used to diminish the variability in data values and can emphasize a certain portion of a spatial data set. By adjusting the classification in a visual representation of a data set specific phenomena can be enhanced or obscured, indicating that the selection of the appropriate class boundaries is crucial.

 

Filtering changes the value at each location in a data set based on the original values at that location and its surroundings.

 

2.    Aggregation

 

Spatial aggregation methods reduce the individual values of a data set to a single value for a specified region or the whole study area. The latter aggregation reduced the number of spatial dimension of the data set from 2 to 0, creating a non-spatial indicator or index value. This loss of spatial information is compensated by the delivery of a clear, unequivocal summary of the original content. Aggregation can also be performed at a regional level, producing a new much coarser representation of the original data. Spatial aggregation methods either deliver spatial or non-spatial indicator values depending on the use of the spatial character of the original data. Aggregations based on general averages or total values are non-spatial as these are independent of the original spatial configuration of the data. The average size of certain types of interconnected areas (average size of all urban areas) is considered a spatial indicator value as this depends on how the urban areas are connected.

 

3.  Combination

Combination of different spatial data layers is one of the key functions of GIS and it offers a powerful tool to provide an overview on many different data sets in one new integrated representation. By overlaying different data layers it is also possible to create a new data layer instead of merely visualising a result. The overlay operation is thus a typical spatial analysis operation available in any proper GIS. A classic example of this type of analysis is to define the area of overlap of two or more separate data layers indicating, for example, the area where new developments are not permitted following a large set of zoning regulations. Overlays are well suited to compare several data layers in a structured manner. Basically three different comparison options can be distinguished (Muehrcke, 1973):

 

1. a data set with another data set that represents the truth as is common in, for example, validation exercises;

2. a data set with another data set, for example, to compare the development over time of a specific phenomenon or to study spatial patterns of related spatial phenomena;

3. a data set with a theoretical data set, to test assumed relations.

 

4.      Valuation

Valuation is an appropriate tool to help interpret the results of spatial analysis operations. By applying a normative and consequently subjective classification operation to analysis outcomes their value is better understood. In essence, this is not a spatial analysis method since it, generally, only applies to non-spatial valuation functions. The main aim of valuation is to make the content of related data sets comparable. It is a common tool in environmental impact assessments and decision support systems that aim to provide clear, easily interpreted outcomes to policy makers and stakeholders. Simple valuation exercises result in a limited number of categories distinguishing, for example, positive, negative or neutral outcomes in relation to a reference value. Monetary valuation that is common in, for example, cost benefit analyses is an example of a more elaborate valuation method.

 

5.        Proximity analysis

A classic type of GIS-assisted analysis deals with the assessment of distance, normally expressed as proximity. Buffer analyses that create zones of influence (e.g. noise contours around roads) surrounding different types of shapes are typical examples of proximity analysis. Plain distance maps that describe the Euclidian or other type of distance to a specified object (e.g. railroad, city centre) offer useful input to various forms of spatial statistical analysis that, for example, aim to explain specific spatial phenomena.

 

6.       Simulation

By describing the relevant relations of a system it is possible to simulate its future state. A common form of simulation (or modelling) is applied in impact assessments that describe the possible consequences of a specific event or policy. Such assessments follow predefined cause-effect relations that are made operational by one or more of the spatial data analysis methods described before. More complex examples of simulation are offered by the models that simulate, for example, the groundwater or land-use system.

 

In addition to these Koomen’s approaches is the Hot Spots Analysis as described below.

 

7.    Hot Spots Analysis

This tool identifies statistically significant spatial clusters of high values (hot spots) and low values (cold spots). It automatically aggregates incident data, identifies an appropriate scale of analysis, and corrects for both multiple testing and spatial dependence. This tool interrogates your data in order to determine settings that will produce optimal hot spot analysis results. If you want full control over these settings, use the Hot Spot Analysis tool instead. (http://desktop.arcgis.com/en/arcmap/10.3/tools/spatial-statistics-toolbox/optimized-hot-spot-analysis.)

Source:

Koomen, Eric Spatial Analysis in Support of Physical Planning (2003)

 

Application of Land Use Planning

A.   Land Use Planning as a Tool for FOOD SECURITY

 

Land use planning can contribute to improving the availability of food

within a defined region at local or national level in a number of ways:

               

o   Through land use planning, areas for food production can be defined,

zoned and protected from being converted into construction land;

o   Through the integration of rules regulating access to land and/or

improving tenure security, food production can be improved as farmers

will invest in long-term measures to improve the soil or start more

expensive cultivations that provide higher yields in the long-run;

 

o   Land use planning in combination with market analysis and infrastructure

planning can improve access to food.

 

 

B.   Land Use Planning: a Tool for Disaster Risk Management

 

·         Land use planning is a very important instrument in disaster risk management. By determining land uses, it affects both the vulnerability of the local population and infrastructure as well as potential hazards, and can accordingly be used to minimize disaster risk. The goal of land use planning for disaster risk management is to achieve a utilization of land and natural resources which is adapted to local conditions and needs and takes into account disaster risks.

 

·         Land use planning can significantly contribute to preventing new hazards, such as landslides and flooding, which are frequently caused by inappropriate land use. Land use planning can also reduce the vulnerability of people and infrastructure by identifying safe locations for settlements and constructions and by defining and applying adequate building standards during plan implementation. Thus, considering disaster risks in land use planning can save human lives and material as well as reduce economic losses. It contributes to sustainable development and poverty reduction.

 

 

C.   Land Use Planning: a Tool for Adaptation to and Mitigation of Climate Change

 

a) LUP for Adaptation

Adaptation consists of assessing vulnerabilities and impacts related to

climate change, identifying and prioritizing adaptation options, often

from a cross-sectoral perspective, and governing the implementation of

adaptation. Impacts and adaptation needs are very different from location

to location; therefore, land use planning has an important role to play in

adaptation to climate change.

 

b) LUP for Mitigation

Land use planning can be used to reduce deforestation and forest degradation

by limiting agricultural expansion, conversion of forests to pasturelands,

infrastructure development, destructive logging, fires etc. Land use

planning can also be used to identify areas for carbon sequestration (as an

environmental service for which farmers could receive a payment), e.g.

through afforestation or for the introduction of agroforestry. An example

is the transformation of coffee monocultures into coffee agroforestry

plantations in which the carbon in biomass and litter can be multiplied by

2.5 through the plantation/cultivation of shade trees. Another way of land

use planning to contribute to mitigation of climate change is the identification

of suitable sites for wind mill parks or for the production of solar

energy.

 

 

Reference:

 

          Land Use Tools, Concepts and Applications, GIZ, 2012

 

Simple Land Use Accounting

 To determine the areas for suitable development, there is a need to deduct first the following land uses and categories from the the total land area:

A.   Protected areas

 

i. NIPAS

strict nature reserves

national parks

natural monuments

wildlife sanctuaries

protected landscapes/seascapes

resource reserves

other protected areas (e.g. virgin forests)

 

ii. Non-NIPAS areas

reserved second growth forests

mangroves

buffer strips/easements

freshwater swamps/marshes

critical watersheds

 

B.   Other reservations

 

i. military and civil reservations

ii. mineral and geothermal reserves

iii. water courses and surface water

 

C.    Environmentally critical areas

 

i. water-related hazards

ii. earthquake-related hazards

iii. volcanic-related hazards

iv. erosion-hazards

D.    Protected agricultural areas

 

               i.    highly restricted agricultural lands - SAFDZ

E. Heritage sites

 

GIS will be very helpful tool in doing land use accounting. GIS Sieve Mapping screens out of consideration those areas that ought not to be built over due to various types of constraints such as physical or environmental (e.g. flood prone areas) and political or legal (e.g. protected areas). Sieve mapping is a necessary support to the land accounting procedure because some of the areas that are not suitable may overlap and are counted twice or many times over. With the aid of maps a particular area with several overlapping constraints is counted only once under one constraint. This way, multiple counting is avoided.

 

 

Reference:

Serrote, Ernesto M., Rationalized Planning System, 2008, p. 100

Tactical Urbanism

 

“Tactical urbanism” is a popular buzzword among urban planners. But what does it mean? According to Mike Lydon, public space expert at Street Plans, tactical urbanism is short-term action for a long-term change. A good example for that are the popular pop-up bike lanes coming up in many cities during the Covid-19 pandemic in 2020. They are cheap, simple and short-term solutions, but there is a tactic behind them. They are intended for a deeper change, such as more safety and space for cyclists.

 

Tactical urbanism can be defined as “a city and citizen-led approach to neighbourhood building using short-term, low-cost, and scalable interventions intended to create long-term change”. Actions can be classified as tactical when they have a vision, a local context, a short-term commitment, a low-risk and high-reward value and the support of a community. Ideally, they even develop social capital by bringing neighbours together. In the long term, pop-up interventions are intended to get an official sanctioning or create change.

 

Due to key trends in urbanism over the last decades, we are currently evolving towards a more human-centred idea of urban planning. Copenhagen’s star planner Jan Gehl is a great example of how to create cities for people, not for cars. Environmentalism, the sharing economy, and sustainability as well as the development of technologies are other trends that enable change in urban planning. A shift in demographics and even an economic recession are opportunities for tactical urbanism – and the good news is that anyone can participate in it!

 

Source: https://parcitypatory.org/2020/07/31/tactical-urbanism/

"How we design and build a smart city and nation?"

 According to Cheong Koon Hean, the following may be done to better plan and design the built-up area.

1.       Smart Planning. This includes data collection. With the data, the planner can do appropriate modeling and analysis of the situations.

2.       Smart Environment. This means getting green in designing the built-up area so that people will be able to enjoy a green environment especially in open and public spaces.

3.       Smart Estate Services. This means introducing green building designs and improving mobility and connectivity of the people

4.       Smart Living. This includes using appropriate green and smart technology so that people can accomplish more tasks.

 

Source: How we design and build a smart city and nation | Cheong Koon Hean | TEDxSingapore accesed  at https://www.youtube.com/watch?v=m45SshJqOP4