Proposed Case Studies for ENVS

Urbanization and the Environment

Urbanization is the process in which green space (fields, trees, wetlands, etc) is converted into black space (concrete and asphalt).
There are a lot of local consequences of this but nothing global (yet)

Alters heat balance and heat exchange to environment . This is clearly seen as well in the thermal image of the central parts of Washington DC
Urban Heat Island:
Stored heat in buildings, asphalt, etc.
Increase nighttime convective circulation.
Urban Wind Alleys but overall reduction in windspeed (10--30%)
Pollutants in Atmosphere: Increase condensation nuclei!

Here is a lesson plan/case study:

Objectives

Understand the factors that contribute to Urban Heat Islands
Map the Isotherms of a typical urban environment
Identify the consequences of urban heat islands
Determine a set of policies that might reduce their environmental impact

Exercises:

1. This image is an 11 micron image of a portion of the East Coast taken in April. A map is overlaid the image to help orient you to the geography of the region. Find the following geographic regions: Lake Erie, Lake Ontario, Long Island, Chesapeake Bay, Delaware Bay, Hudson River, Finger Lakes, Appalachian Mountains.

Notice that on this day in April, the land is warmer (it appears darker in the image) than the Great Lakes and the Atlantic Ocean. Urban heat islands appear on the image as "dark blemishes." The city of Pittsburgh is marked to help you recognize the heat island feature. Find the following urban heat islands: Washington, New York Metropolitan Area, Philadelphia, Buffalo, Cleveland, Albany, Harrisburg, Richmond and Syracuse.

2. This map is of a real urban area in which local temperatures were measured on a November morning. We will call this place PixelVille Using the map, construct an isotherm representation of the temperature distribution in contours of 2 degrees. (This is most easily done by printing the map and drawing contours on it).

For another example, consider the case of Melbourne Australia .

Questions/Policy Considerations for this urban environment:

What are the physical characteristics of PixelVille

What type of map (soil map, land use map, or road map) would be best to explain the urban heat island?

How would you present this material to the PixelVille City Council?

Where are the highest and lowest temperatures? Are they correlated with any particular activity in PixelVille?

How would the river moderate the climate? What influence might the transportation corridors have on the temperature?

What are the chief mechanisms contributing to urban heat islands?

What are the consequences of the Urban Heat Islands in terms of household energy consumption?

What can environmental planners do to reduce the impact of urban heat islands?