APES 2.5 - Impacts of Urbanization

Lesson 2.5

• Describe the effects of urbanization on the environment.

• Describe methods for mitigating problems related to urban runoff.

Impacts of Urbanization

Click on each hotspot to learn about some positive and negative aspects of urbanization.

Urbanization

vs.

Urban Sprawl

How can we reduce urban runoff?

Urban Heat Islands

Urban heat islands are urban areas that are warmer than the surrounding rural areas. This is due to a combination of factors, including:

• Heat-absorbing surfaces: Concrete, asphalt, brick, glass, and steel absorb and re-emit the sun's heat
• Heat-generating activities: Engines and generators produce heat
• Lack of vegetation: Trees and other plants provide evaporative cooling

What is Urbanization?

Urbanization is a shift from a rural and agriculture-based lifestyle to a densely populated human settlement with non-agricultural jobs.

• Urbanization happens as countries go through the Demographic Transition.

Saltwater Intrusion

Cities on coastlines (there are many) draw large amounts of freshwater from wells. If they draw too much, the freshwater becomes depleted, and saltwater moves into fill the empty space. This is called saltwater intrusion, and it results in contanimated drinking water and an icreased cost for water treatment.

Saltwater intrusion can also be caused by sea level rise!

What is Urban Sprawl?

Urban sprawl is the expansion of cities to cover a larger area. It includes:

• Creation of suburbs (low-density housing)
• Developing previously untouched land
• Commuters and an increased use of personal vehicles

Methods to Reduce Urban Runoff

PERMEABLE PAVEMENT

GREEN SPACE

SMART GROWTH

Smart growth utilizes compact designs, which reduce the amount of impervious surfaces.

Green spaces stragetically placed next to roads and the bases of buildings help absorb excess water.

Different pavement options increase the amount of water that infiltrates the soil underneath.