Lecture Notes on Urbanization

Introduction

• Topic: Urbanization (Topic 5.10)
• Definition: Conversion of natural landscapes into urban areas (cities/towns).
• Objectives:
  • Describe environmental effects of urbanization.
  • Discuss causes and expansion of urbanization.
  • Explore solutions to urbanization issues.

Environmental Effects of Urbanization

• Saltwater Intrusion:
  • Occurs when coastal cities withdraw excessive groundwater.
  • Lowers water table, reducing pressure against seawater intrusion.
  • Sea-level rise exacerbates saltwater intrusion:
    • Caused by thermal expansion and melting ice caps.
• Increased Fossil Fuel Combustion:
  • Production of cement and asphalt releases CO2.
  • Use of construction machinery and deforestation contribute to CO2 emissions.
  • Urban waste contributes to CO2 and methane emissions.
• Impervious Surfaces:
  • Urban areas replace pervious land with impervious surfaces like concrete/asphalt.
  • Limits groundwater infiltration, increases runoff.
  • Disrupts natural water cycle and leads to urban runoff.

Urban Sprawl

• Definition: Population shift from dense cities to less dense suburbs.
• Causes:
  • Cheaper property prices in suburbs.
  • Affordable cars and gasoline facilitate commuting.
  • Domino effect: neighbors moving encourages others to leave.
• Consequences:
  • Decline in city tax base and services.
  • Businesses move to suburbs, leading to urban decay (blight).
  • Positive feedback loop: fewer services lead to more people leaving.

Role of Highways and Gasoline Tax

• Expansion of highways encourages suburban living and commuting.
• Gasoline tax revenue used to build more highways.
• Positive feedback loop: more driving leads to more highway construction.

Solutions to Urban Sprawl

• Urban Growth Boundary:
  • Zoning law preventing expansion beyond a set point.
  • Encourages vertical building and efficient land use.
• Efficient Public Transportation:
  • Affordable and reliable transport encourages city living.
• Mixed Land-Use:
  • Combines residential, business, and entertainment in close proximity.
  • Enhances community appeal and reduces suburban movement.

Practice

• Suggest a solution to urban sprawl and identify possible economic consequences.

Conclusion

• Reminder to practice describing advantages, disadvantages, or unintended consequences of solutions.
• Encouragement to engage with additional resources and think critically about urbanization.