Choropleth Map Exercise

Objectives:

Produce a set of choropleth maps for the United States from one data set. Use desktop mapping with GIS to compare the automated computerized groupings of the base data. Finalize the map products in Powerpoint and export them in jpg format. Produce html pages by which to display your work.

Instructions:
Locate an uncopyrighted data source (government) on line for data for the fifty states. All fifty states must be represented. This should be new data that is not contained in our database already. This table should include the state names and one column of associated data.

Copy or download this data to disk. Insert it into Excel. Clean it up removing any long field names, spaces, and blank rows. Also, be sure that the field properties are properly set. Then, turn it into a .dbf 3 file, and import into both ESRI software. Map it using: G:\ALLGISDATA\??\states\states.shp. The ?? is the ArcView 3.3 dataset. (Sorry, I donít remember the folder name at the moment.)

In ArcView 3.3, open the state's table by clicking on the Open Theme Table icon or menu option. Click on the table icon on the program window. Add your .dbf 3 file. Edit your table as necessary to make it functional. (Ask for help when needed.) Click on the theme window, then on the new table, highlight the column heading with the state names, click on the states' table, and highlight the column heading with the state names.

Click on the join icon in the center right side of the toolbar. Click on the legend in the view window to open the Legend Editor. Produce a choropleth map of YOUR new data with each type of classification available. Use an appropriate conformal projection for this activity.

Export each file as a .jpg.

Insert them into Powerpoint to produce a cartographically sound map.

Save these maps as "av#_ _.jpg" (# being 1 through 5 of the different types of classification.)

Identify which classification produced the best map. Insert your data into ArcGIS and produce only this version of the map.

Produce html pages to hold each of these maps and explanations.

Comments: Choropleth maps are easily produced, however, the quality is highly variable. This exercise aims at providing you opportunity to play with these programs and be exposed to the real life problem of data availability and functionality. Don't expect your data to fit right in and be usable. Part of the adventure is trying to figure out how to get the data to work