2/26/25 - Urbanization: Why are Cities Growing?

How are urban areas changing?:

• Globally, we are undergoing urban transition as populations become more urban and less rural.

• Urban areas are places where many people live in relatively dense settlements and work nonagricultural jobs.

The urban transition from a historical perspective:

• Historically and today, cities form around trade and transportation hubs and centers of political power.

• Today, 25% of all people live in a city with 1 million people.

Urbanization and environmental impacts:

• Building cities has come at the cost of transforming natural landscapes and habitats like forests and prairies.

• Resource extraction and waste generation have resulted in high levels of pollution and increased ecological footprints.

• Human health problems associated with urban living are referred to as urban penalties.

• Improvements in sanitation and public health helped reduce mortality rates in urban areas to less than in rural areas, but some developing cities are still plagued with numerous diseases.

The opportunity of urban areas:

• As the city population increases, wages and wealth also increase.

• An increase in urban density, the number of residents per unit of space, results in an economy of scale in which per capita costs decrease.

• More people using shared resources presents opportunities to solve environmental problems.

• Efficiency gains and reduction of GHG emissions are a result of sharing heating and cooling usage and costs in multi-dwelling buildings.

What are slums?:

• An urban area characterized by substandard housing, a lack of formal property ownership arrangements, inadequate urban services, and high rates of poverty.

• Indoor plumbing is nonexistent and open sewers pollute the streets.

Opportunities in slums and cities in the developing world:

• Often, slum residents fled war and political oppression or south jobs when farm labor was no longer needed.

• Bright Light syndrome describes cities as places of opportunity, excitement, and freedom to pursue all aspects of life.

• The informal economy is comprised of small ventures that operate outside of government regulation and taxation.

What is suburban sprawl?:

• Urban populations spread away from cities across areas with lower population densities.

• Occurs when policies increase the supply of land for development while reducing the transportation costs associated with commuting.

• Less dense more resource-intensive form of urbanization that has its own environmental and social challenges

What is urban sprawl?:

-Metropolitan areas (cluster of densely populated suburbs and cities).

Characteristics of suburb sprawl:

• Suburbs tend to develop into single-use zones.

• Residential subdivisions, shopping centers, office parks, and schools are examples of these distinct zones.

• The density of residential development can be calculated as dwelling units per acre and includes single-family homes, apartments, and condos.

• Another measurement includes a floor-to-area ratio, the total floor space of a building relative to the area of land that it is built upon.

What are the problems of suburban sprawl?:

• Sprawl consumes undeveloped land, reduces pedestrian travel, and increases vehicle ownership and miles traveled per capita.

• Sprawl has replaced substantial acres of natural and agricultural ecosystems.

How street design shapes transportation:

• Typical suburban street patterns have changed traditional grid patterns in the US.

• Suburban patterns are curved and disconnected which produces an indirect route from houses to shopping areas or schools that is less pedestrian-friendly.

How did suburban sprawl develop in the US:

• Moving up in class status equated to moving out of the central city.

• Zoning was created to separate residential areas from the pollution of heavy industry and also separated people by class, race, ethnicity, and religion.

Restrictive Covenants and Redlining:

• Many residential neighborhoods in the US discriminated through restrictive covenants that barred ethnic groups from purchasing or occupying property.

• Redlining: areas where different races were not allowed.

Building policies:

• Gov. agencies protected banks against loan defaults on single-family homes in the suburbs in the 30s and 40s.

What is urban planning?:

• Development of guidelines to shape the future of urban areas.

• Planners consider the scale of a neighborhood by assessing the needs and integrating both nature and aspects of the physical environment.

The challenge of planning:

• The need to operate at both a local and regional scale is called the planner’s dilemma.

• Planning at the city level requires both regional and local planning because daily activities send residents into surrounding areas.

Transportation:

• Modal split is the percentage of travelers in an area using different types of transportation.

• Transit-oriented development - integrates public transport.

• Pedestrian-oriented development - integrates pedestrian travel