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Assignment C: Mapping Data with Online GIS
Assessing children's risk of exposure to lead.

(Part 1 - do in lab, Part 2 - due July 13)

Scenario: You are conducting a survey in the community to assess the children's risk of exposure to lead. Because of a very limited budget, you are only able to conduct a few dozen home visits. That is why you must look at demographic data to pinpoint the most likely places to begin field research of children's risk of exposure to lead.

In this assignment you will use GIS methods to collect and analyze maps of census data. Think about what combination of factors in an area would make it a likely candidate for further investigation. That is, where is it most likely that children are being poisoned by lead?


Part 1 - Choose a site and gather maps of data

Data for this project may be acquired online using primarily the U.S. Census Bureau's 1990 data
1990 Census Lookup - by zip
Statistical Resources on the Web Demographics and Housing - census data
U.S. Census Bureau's TIGER Mapping Service "Coast to Coast" Digital Map Database - TMS Version 2.5
Additional detailed base maps with street names can be accessed using Yahoo.com - maps

Choosing zip code(s) for analysis:

Choose a specific place or community in the United States that you would like to research. Look up a map of the zip codes for the area in the yellow pages. Using the 1990 Census Lookup - by zip Look up the "year structure built" census data for each zip code and calculate the percentage of housing units built before 1950. Pick one or two adjoining zip codes where at least 27% of the housing was built before 1950. This will be the area of analysis. For more information, read "Lead Inform" On the ground . . . You may also choose a zip code based on its proximity to highways and major arterials.

Finding data about the area:

Using the TMS Version 2.5, You are to generate and download at least five maps (and their legends) of different themes related to the assigned research theme and place. Remember, all five maps must be of the same place and scale so they will line-up when overlaid.

Open the TMS Version 2.5 and scroll to the bottom to where -You can search for a zip code- to find your chosen zip code(s). Zoom in so that your chosen area of analysis is centered and takes up most of the map. Once you are happy with the map, bookmark (favorites) the map so you can bring up the exact same map extent and zoom again later.

Use the buttons, check boxes, and pop-up menus to select features and data to display. Remember to be very selective so as to not clutter the map and make it unreadable. Note that some features and data are only appropriate or only available at certain scales.

For this assignment, use the menus under "Map Census Statistics." Set the "level" menu to either block group or census tract. Then select the type of data you want to display under the "theme" menu.

Recommended data themes related to children's lead exposure:

You will need to try different options and settings for maps to come out. It involves considerable trial and error.

Saving Data Maps:

Maps and images will be saved into one folder, and will be used to illustrate a report (remember to always save everything into the same folder). Each map has a legend which is a different image - so save them both and give them similar names (e.g. mapname.gif and mapname_leg.gif).

To save maps and images, Ctrl-Right Click *on* the image and you will get a menu with an option to "Save Image As...", or "Save Picture As...". Then you can just give it mapname.gif
Be sure to save them all to the same folder.

Bring your maps on disc to class April 25th (bring a backup copy on a second disc).


Part 2 - Analysis of Maps and Final Essay

Map Analysis

Bring your maps on disc to class April 25th. The goal is to pinpoint the most likely places to begin field research of children's risk of exposure to lead. Map overlay and analysis may be done manually or using a GIS or other graphics software. I will explain your options in the computer lab.

Final Map and Essay:

The final product of this assignment should be an essay and a detailed map that pinpoints the most likely places to begin field research of children's risk of exposure to lead. Your final essay should include analysis methodology, research questions, critiques of the data categories or levels of resolution, and a summary of what you learned. Please spell out exactly how you arrived at your conclusions.

To submit the essay on disc: the final illustrated essay must be saved as an html document and submitted as 2 copies on 2 discs.

To submit the essay on paper: If you do not know enough about computers to illustrate the essay, simply print out the maps, cut and manually paste your assignment together.

Documentation:

Hand in the final map and essay along with all of the maps and other data used in your research. Don't forget to include full citations and a bibliography to tell me where you got your maps and other information. For more information, please read how to hand in assignments.


Related links:

Maps and Technology: GIS/GPS Resources

Dumbing Down the Children--Part 1, Part 2, Part 3

Lead Inform - On the ground . . .

Statistical Resources on the Web Demographics and Housing - census data

Don't forget to read the Frequently Asked Questions about the TMS Version 2.5 such as:

Q: Sometime forcing on features doesn't work. What is the deal?
A: There are hardcoded thresholds for feature layers. Most of the features wont
display until you get to a map scale around 1:1500000. This threshold was put in
place to keep users from swamping the CPU with unreasonable requests. (eg. draw all
streets at the US Level)
 
Q: Is there any legal/copyright issues using these map?
A: No. The maps are public domain. You may use them how you wish.
 
Q: How can I download the images I create?
A: That depends on your browser... With Netscape and Microsoft Internet Explorer
you can Ctrl-Right Click *on* the image and you will get a menu with an option to
"Save Image As...", or "Save Picture As...". Then you can just give it mapname.gif.
 
Q: The map image is broken, What gives?
A: This could be a number of problems, but the most frequent is a browser
problem... Some browser don't recognize the HTML code &INPUT
TYPE=IMAGE...>. I think Netcom NetCruiser still has this problem, and older
versions of web browsers. You'll need to upgrade your web browser.