Geography 241
Lab Activity 1 - ArcGIS 9.3: ArcCatalog and ArcMap

This lab presents an introduction to ArcGIS 9.3 and will allow you to explore the display and manipulation capabilities of the application. It also presents several modules that are incorporated within the ArcGIS framework.  This work can be completed and submitted as an individual or as a group of two (submit one activity for two persons). Both of you will receive the same grade. At times I will refer you to the ArcGIS HELP functions.  It is important that you gain comfort and confidence in working with these help functions.  The Help dialog looks something like this:

As you can see there are several ways to access help, including a table of contents, searchable index, and a favorites list.  From the welcome screen (seen above) you should read and become thoroughly familiar with (at least) the Getting Started part of help.  Under this section read and become thoroughly familiar with:

The more quickly you become familiar and comfortable with the help resources available to you the quicker you will become a GIS maven.  There are also some interesting tutorials and a guide to the toolbars in the various modules we will be using this term.  Any time you have a question while working in the lab you should always first exhaust the help system in trying to resolve the question yourself.  If you cannot resolve the question with the help system, then ask for help from either me or the lab assistant (if present) and we will be glad to help you.  Learning is a cooperative process that requires efforts from both the instructor and the student - we all know this but sometimes a gentle reminder is appropriate.  The more adept you become at helping yourself learn, the more successful you'll be here and beyond.
 

In this lab we will have a task of creating a choropleth (see what you can find on this in the text) map of cook county that displays a quantitative measure of one of the data items (attributes) collected at the Census Tract level in 2000.  We will use the data from a zip-compressed data file that can be found here.  Save this file (download it) to your desktop or flash drive.  Use the in-lab application to extract the data folder (7-Zip) by right clicking on the folder and selecting the application.  This folder contains a map layer (an ESRI Shapefile) and a data table from the 2000 census that we will Join to the map layer. It also contains a documentation file describing the census data table and a Google Earth KML version of the file (for reference).

Always save your work frequently in this course.  This is not as simple as it may seem.  When you make changes to a shapefile or the tables associated with it acting as an editor you may be asked to save your work - this is one form of saving and is important.  This will save the actual data - in effect the changes you have made - to the layer you are working on.  Perhaps more commonly, users will save their "Map" using the ArcGIS desktop - this will create an 'mxd' file that for all intents and purposes looks like your map but be careful - it doesn't contain any of the data, layers, or graphics that your map is made up of.  This file is a set of pointers that will recreate your map from the various images, shapefiles, and tables that you've used to create it, but... and this is a big but... it must have access to all these things and they must be in the same relative location as they were when they were saved.  This makes moving around "Maps" somewhat complicated (for about 85% of my students it causes extreme consternation at least once a term).  There is a reason for this design - it is a quirk, not a flaw.  Possible ways to reduce problems are to keep everything on your flashdrive - although this can slow operations down as writing to these drives can be slower than to the hard drive. This isn't foolproof either as systems occasionally use different letters for flashdrive assignments (which can cause the mxd file to fail).  I actually don't use these files much, but that's another story.

I. ArcCatalog

 Begin by opening ArcMap using the Start menu (Start | All Programs | ArcGIS | ArcMap), or from the Quick Launch bar at the bottom of the screen .

When you've opened ArcMap, open an ArcCatalog window using the ArcCatalog button in ArcMap.

A few words about ArcCatalog:

The Catalog is the place where you can assemble connections to all the data you need to use. When you select a connection, you can access the data to which it's linked. The connection might access a folder on a local disk, a database on the network, or an ArcIMS Internet server. Together, your connections create a catalog of geographic data sources.

The Catalog tree displays all the items in the Catalog and illustrates the hierarchy in which they are organized. When you select an item in the Catalog tree, the Contents tab lists the items it contains. By pressing the Up and Down arrow keys on your keyboard, you can quickly select the items displayed above or below the currently selected item in the Catalog tree. The Up One Level button on the Standard toolbar selects the next item up in the Catalog tree's hierarchy.

Use the Catalog to connect to the folder on your desktop. Mine looks like this:

Explore the data in this folder using the Catalog.  Notice that there are three different views of objects in the Catalog; contents, preview, and metadata.

Look around in the folder and find the files:

Open these into ArcMap. (Hint: You can drag and drop these from the Catalog into the Table of Contents or the Data Frame, although I have found that sometimes this does not work as well as one might expect.  Try to get used to using the open file dialogue with this button in ArcMap instead.) Spend some time familiarizing yourself with the Catalog.  You will benefit greatly as the term passes by not rushing through these early activities - in fact this is a good habit to get into.  Don't dawdle but also don't rush.

 

II.  ArcMap

Move back over to the ArcMap window from ArcCatalog.  This is the main framework where you'll do most of your work creating maps and manipulating information in ArcGIS.  You should work to master this part of the application.  A few initial words about ArcMap:

ArcMap is the premier application for desktop GIS and mapping. ArcMap gives you the power to:

Visualize. In no time you'll be working with your data geographically: seeing patterns you couldn't see before, revealing hidden trends and distributions, and gaining new insights.

Create. It's easy to create maps to convey your message. ArcMap provides all the tools you need to put your data on a map and display it in an effective manner.

Solve. Working geographically lets you answer questions such as "Where is...?," "How much...?," and "What if...?" Understanding these relationships will help you make better decisions.

Present. Showing the results of your work is easy. You can make great-looking publication-quality maps and create interactive displays that link reports, graphs, tables, drawings, photographs, and other elements to your data. You'll find that communicating geographically is a powerful way to inform and motivate others.

Develop. The ArcMap customization environment lets you tailor the interface to suit your needs or the needs of your organization, build new tools to automate your work, and develop standalone applications based on ArcMap mapping components.

Geographic information is displayed on a map as layers; each layer represents a particular type of feature such as streams, lakes, or highways. Layers are listed in the ArcMap table of contents and can be further organized into data frames. A layer doesn't store the actual geographic data; instead, it references the data contained in coverages, shapefiles, geodatabases, images, grids, and so on. Referencing data in this way allows the layers on a map to automatically reflect the most up-to-date information in your GIS database.

The table of contents lists all the layers on the map and shows what the features in each layer represent. The check box next to each layer indicates whether the layer is currently drawn on the map or not. The order of layers within the table of contents is also important; the layers at the top draw on top of those below them. Thus you'll put the layers that form the background of your map, such as the ocean, at the bottom of the table of contents.

Layers in the table of contents can be further organized into data frames. A data frame simply groups, in a separate frame, the layers that you want to display together. You always get a data frame when you create a map; it's listed at the top of the table of contents as "Layers", but you can change the name to something more meaningful. You may want to add more data frames when you want to compare layers side by side or create insets and overviews. When a map has more than one data frame, one of them is the active data frame. The active data frame is the one you're currently working with. When you add a new layer to a map, it is added to the active data frame. You can always tell which data frame is active because it's highlighted on the map and its name is shown in bold text in the table of contents.

Much of what you'll do in ArcMap will be accessed through the Properties dialogue boxes of the respective Layers and Data Frames. These can be most easily accessed by pointing to the Layer or Data Frame and right-clicking, then selecting "Properties".  The Dialogue for a particular Layer is shown below:

As you can see there are many parts to this dialogue, accessed through a system of tabs at the top.  This is the "Symbology" tab of the layer dialogue.  Explore the different tabs and familiarize yourself with their operation.  You will also use the data frame properties dialogue.  It can be accessed by pointing at the "Layers" label at the top of the table of contents and right clicking, then selecting "properties".  This is the Data Frame - there can be more than one of these open in an ArcMap document.  These may be useful as you begin to create more complex maps - for now we only need one.  This dialogue also uses a system of tabs to present different screens.

There are also a number of toolbars accessible to you that can access through the View - Toolbars menu selection. These can be turned on and off interactively and will be very useful to you as we proceed. Take a look at these now and think about what they are used for.

Start your work in ArcMap by by creating a Join of the attribute table in our census tract data layer with the census data we have opened in our map table of contents.  this can be accomplished by right clicking the tract layer and selecting Joins and Relates and then Join - it will look something like this:

This will present a dialog for joining the data in the table to our map layer, based on a common field.  The dialog looks something like this:

Joins allow us to connect rich data sets to the features in our map based on a common field in their data tables - this opens the door to creating rich relational databases.  Make sure you click the "Advanced..." button and select "Keep only matching records".  The data table actually contains data for every county in Illinois so it can be used for many types of maps and for detailed maps of any of our counties.  When your dialog looks like the one above click "OK" and all of the data from the SF file will be added to your attribute table for Cook County.  If you want to look at the raw data you can by right-clicking the layer and selecting "open attribute table" - do this and then close it when you've had your fill.

Now you are ready to start mapping.  Access the properties of our layer by right-clicking it and selecting "properties" in the Table of Contents.  Select "Quantities" on the left of this dialog.  The dialog looks something like this:

Now you can select an attribute field to map by using "Value".  Most of these are raw values so they may need to be "Normalized" (divided by) another field.  We'll talk more about this in class - most raw data needs to be normalized to convert it to a comparable number.  Only data that is recorded as some measure of central tendency should not be normalized (normally...)  Whew..

The classification dialogue can be accessed using the "Classify..." button.  Data classification for the purposes of mapping is a massive topic - a concise summary can be found here.  The dialog looks something like this:

This offers several choices for your map.  Notice that the histogram (it may appear different depending on the dataset you select to map) displays the locations of the class boundaries for the classification scheme you have selected.  As you change the scheme (e.g. quantile, natural breaks, etc.) the class boundaries will move in the histogram to their new location, and the "Break Values" will change.  You can also view the percentage of the total values that are represented in each class.  Careful here - there are wrong and right choices.  Think about what you are trying to do - i.e. show the variability of a particular census statistic in Cook County, Illinois.  There are also many ways to make mistakes with color in mapping.  ArcGIS tries to make selections easy for you with a system of palettes that can be easily selected but the default choices are generally BAD.  Don't settle for a default color scheme without trying some different options and becoming more adept at map design EVER!!!  Use the tools available to you to make an effective and aesthetically pleasing map that clearly communicates what you are trying to show.

When your map is well-centered, switch to the "Layout" view of the Data Frame .

Again, map design is a massive topic - the field of map design is encompassed in the discipline of Cartography, which is unfortunately becoming a subset of GIS.  Look here for a brief guide to considerations when designing your map.  Your final map should be formatted to most effectively use the space on the page, whether designed as landscape or portrait format.  It should include an appropriate title, legend, scale (Representative Fraction please), a text box that briefly describes the process of making the map and the data used (fine print please, use the 634-page documentation PDF file for all the information you ever wanted to know about the census), and your name(s) (also fine print, lower right corner).  These can be added using the "Insert" menu.  Make certain your map has a Legend and North Arrow. 

You also may (optionally) explore the ArcScene module - this is a gateway to 3D Analyst - an extension that should be available on your desktop (it's also available through the start menu) - it runs in a separate window. It works in a very similar fashion to ArcMap but the representation space is presented using an active simulated 3D interface.  You can Join and represent data in a similar fashion to ArcMap with some very powerful additional functions.  Of particular interest to this dataset is the "Extrusion" tab on the Properties dialogue.  This allows you to "extrude" prisms shaped like the tract polygons to a height that has been calculated from the census dataset - cool.  You can then rotate the model to achieve its best aspect.  When you've done this you "export" a 2D image of the model as a JPEG file and then insert this "picture" into your map layout as an alternative view of your data - again, cool.  This is an optional component of this activity - my sketchy description of this technique is intentional - it will require you to make a couple of discoveries using the resources at hand.

There should be 2 printers available to you in SAC 224, GISJet (the b/w laser printer) and DesignJet (the large-format color inkjet plotter).  Format the map as a "C" - size composition and plot it on the Designjet Plotter in the lab. Aces!!!

Also, in a separate word document, answer the following questions:

1.  What attribute value did you choose to map?  Why?

2. What data model is used on this layer?  Define this data model.

3. What data classification scheme did you choose? Explain how this scheme works. Why did you choose it?

These answers should be printed on the GISJet.

Your activity is due September 23, at the end of class.