GEOG 413 - Computer Cartography

Lab 6: Point symbols and bivariate maps.

The purpose of this exercise is to introduce you to different methods of using graduated circles (or other point symbols) to map your data. For this lab, you will be using the GIS software ArcMap. The first part of the exercise will be straightforward graduated symbol mapping using

We will be using two datasets: One of WA State, the other of the Lower 48. Grab both from the lab6 subdirectory on the J drive. Make everyone's life easier and put all your data and saved files in a single subdirectory on your flash drive.

The first part of the exercise will be a relatively straightforward proportional symbol mapping exercise using the US dataset.

OK - you're ready to start working in ArcMap.

Start by opening ArcMap: Start - Programs - ArcGIS - ArcMap

When a window pops up asking about how to start ArcMap- keep the default which is a new empty map.

Load the lower48 dataset (file - add data).

Click on the little box next to the file name - this will draw the map. Obviously, it is a map of the US, including state boundaries. There is a data file associated with this map. To view it, right click on the filename (left side of screen), goto 'open attribute table.'. Here, you can browse the data. Some of the headings are a bit cryptic - you know as much as I do....

We will start with a simple graduated symbol map. Make sure the map is active (click on it). Right click on the "lower48.shp" text in what sort of appears to be the legend and select 'Properties.' Click on the 'symbology' tab, click on 'Quantiles' - the proportional symbols. You will also have to select a column of data to map in the 'fields' 'value' box. Play with the minimum size of the symbol and the number of classes. Also, play with the colors - remember, this map will be printed in black and white. A question to answer (yes, type it out for me) - how does ArcMap determine the size of the circles? Are there any options (for circle size)?What's that 'appearance compensation' thing? You'll need to goto help to answer this. Or even onto the web (Google is your friend). Next, fiddle about with the 'graduated symbols' mapping option (right above 'proportional symbols). How does this differ from the proportional symbols mapping options? Why might you use this option rather than the proportional symbols option? After playing a bit, pick one of the columns of data to make a map. Do so. continue...

Once you are happy with this map, Click - View - Layout View. This is where you make your pretty maps. You can change to layout view in the file - page setup area. Add a legend with the insert - legend tool. To edit this legend, you will, effectively have to ungroup it. Select it, right click on it and click on 'convert to graphics' - the right click again and choose ungroup. Now you can mess with it all you want. Add a title, neatlines, your name, etc. Print this out. (or make a nice pdf file [file - export] and get it to Sarah to print in color). Remember, this is a cartography class, not a GIS class - I will be looking very carefully at the details of the cartography.

Now for the more complicated map. In this case, you will be looking at the WA State dataset. Close ArcMap, reopen, and load the WA dataset. You will again be making a graduated circle map, only this time using population as the circle size and mapping something within the circles (like a pie chart). In the layer properties window, display tab, select 'charts - pie' as your map type. Add the fields you want to map (ie - never married, married, separated, divorced, and widowed). These must be something that will add to 100% of the population (ie - the entire population falls into one of the just listed married categories). Now, click on the 'size' button. In the next window, you will set the circle size to vary according to the pop1990 field. Map it. See how it looks. Play a little. Make sure the point sizes are appropriate. And that you like and can discriminate between the colors.

As you will have to print in color, it is important to save frequently for this map. Goto File - Save and save the file in this lab's subdirectory on your zip/flash disk. MAKE SURE THAT ALL YOUR DATA AND THIS FILE ARE SOMEWHERE IN THE SAME SUBDIRECTORY.

Go back to your view and right click on the filename, click on 'label features.' This will put all the county names on the map. You'll note that the placement often sucks. To mess around with the placement, right click on the map itself and click on 'convert labels to annotation.' Now, you can select, move, and edit the county names. Make sure all the county names are in the best spot you can find. You can also reposition the graduated circles by right clicking on the map and selecting 'convert features to graphics.' Before doing this, make sure you save! Accept all the defaults. You will notice as it redraws that the county outlines are gone. Goto file - add data and add another copy of the wash dataset. Kinda roundabout, but it works. For some reason, you also lose your pointer (at least you cannot select anything) - go back to the toolbar and click on the arrow pointer thingy - now you can select those darn charts and move 'em aroung. Don't save again until you're sure that you can select everything and move them around. Now, make everything look nice (labels and points in their proper positions).

save frequently. And, if you make significant changes, save to a new filename. Then you can always go back to what you had.

Make a layout. Add all the usual stuff - title, legend, etc.

Save frequently.

When you're done, save your file as a pdf and have Sarah print the second map in color for you (and the first, too, if you wish). Hand in both maps and the answers to the italicized questions above.

Due date: Tuesday, 19 February. 5 points.

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