Geo325: Business Geographics
Lesson 1 ~ Introduction to GIS Concepts and Applications

Lesson Overview. All GIS's need to display information in three ways: in a map, in a table, and in a layout. Maps show features in a two-dimensional space. Tables store information about the map features. Layouts allow us to combine various elements, such as a scale bar, a north arrow, text, tables and maps in a nice presentation format. In this lesson you'll learn how maps, tables and layouts are similar, how they are different, and how to move from one to the other.

You'll also learn the three basic geometric elements a GIS uses to represent features: points, lines and polygons.

Part 1: The Map Window

Let's launch MapInfo, one of the GIS programs we'll be using for this course. Launch MapInfo by double-clicking on the MapInfo icon on the desktop. At the Quick Start window that opens, select Open a Workspace, click Open, and then navigate to C:\Geo325  and click on INTRO.WOR. This opens a previously created workspace, as MapInfo calls it.

Our lessons have been designed so that you can have your GIS application and the current lesson open side by side. To quickly size them for side-by-side viewing, move your mouse to an empty area in the task bar (the solid blue area near the Start button, bottom of your monitor). Right-click in the blue and then select Tile Windows Vertically.  Now you can read the lesson and see the application at the same time.

Maps Represent Features in the Real World: Points, Lines and Polygons

You are now in a map window, looking at a map of Chester County. Look closely and you'll see points, lines and polygons. Some of the polygons are filled with yellow, others are hollow. Most of the roads are black but one is red. All the points are represented with the same symbol, a solid green circle.

Points have only location--a single x-y coordinate. A point could be used to represent a business location, a customer's place of residence, a bus stop on a transit stop, or other specific location.

Lines have location and shape. A line could be used to represent a street, a bus route, a river, a demand line between a customers and stores, or other linear feature.

Polygons have location, shape and area. A polygon could be used to represent a lake, a boundary of a census tract, a zip code boundary, or other some other feature with area.

On this map, the points represent the local high schools, the lines represents streets and roads, and the yellow polygons represent the boundaries of the urban areas.

Controlling Layer Order and Visibility

A GIS layer contains features that are related or similar. For example, a layer might show all branch locations for a bank. A hydrology layer might contain streams and ponds. Organizing our map features into layers gives us better control over our map; it keeps things from becoming too complicated.

GIS applications allow us to control which layers are visible and the order in which they are drawn. Let's explore the layers in this workspace. First, find your Main Toolbar. (Seem image right.) We'll cover toolbars in detail later. For now just find the Layer Control tool ( ) and click it.

The Layer Control window (the dialog box now open in MapInfo) shows all the layers in our workspace. Within this window we can control the order in which layers are drawn on the map, whether they are visible, how they are drawn (colors and patterns), whether the features are labelled and several other characteristics.

In the Layer Control window we can see we have five layers. They are listed by name in the Layer Control box.

The first layer in the list, the Cosmetic Layer, will always be present in MapInfo. For the most part we will not modify the Cosmetic Layer.

Reordering Layers. The order in which the layers appear in the above list is important. Features on the map will be drawn in the same order they appear in the list. That is, a layer that is under another in the list will appear underneath that layer on the map. Why is layer order on a map important? If solid objects like parks, census tracts, city boundaries are drawn on top of other features they will obscure smaller features such as bus stops and roads.

Let's experiment with changing the drawing order of layers.  Click on the streets layer in the Layer Control Box. Move the streets layer down by clicking the Down button. Then click Ok to see how your map changed. What happened on the map? Parts of the streets layer are gone. In fact, they are not gone but merely hidden underneath the Urban areas, which appear in solid yellow.

Layer Visibility. Let's change which layers are visible. Get back into Layer Control . Under the visibility column (it has the eye at the top), check the box to the right of 'water.' This makes the water layer visible. Click Ok to close the Layer Control box. How did this change your map? Do you see blue lines now, representing the streams and lakes in Chester County?

Measuring On A Map. Another powerful aspect of a GIS is that features are stored in real world units. That is, not only are they the correct shape and positioned correctly relative to one another, they are also correctly sized. So we can measure things on our map!

Let's do that now. Select the Ruler Tool on the Main Tool Bar  . A small dialog box opens.

Let's measure how far it is from Henderson High School to the southwestern corner of Chester County. Click on the map near the green dot that represents Henderson. Now click near the southwestern tip of the County.  (North is almost always up in a digital map, so southwest is the lower left corner.) Read the distance from the Ruler box. You should get about 33-34 miles. Since a GIS represents features in real-world coordinates we can gain a lot of information about features, such as their real size, the length along the road, and distance between features.

To stop measuring with the ruler, hit the Escape (Esc) key on your keyboard.

Tool Bars Keep It Simple

Zooming In and Out

Zoom In. Let's use the zoom-in tool to see mapped features closer. Select the zoom-in tool by clicking on it. Now move your mouse over the map, click once and release the mouse. The program will immediately zoom closer at the point you clicked. Features will appear larger but you'll see fewer features on the map. A single click with this tool zooms you in by about a factor of two.

Zoom Out. Now let's use the Zoom-out tool. Can you find the Zoom-out tool on the Main Toolbar? Select the tool on the Main Toolbar and then click the center of the map. Use this tool as many times as needed to be back out where you can see all of Chester County.

Zoom In to a Specific Rectange. The Zoom-in tool can be used two different ways. The first, which we did above, is a single click with it, right where you want to zoom. The second is to describe a specific rectangle where you want to see more closely. Let's say you wanted to zoom in tightly on the West Chester area. See where Henderson High School is? See the yellow areas behind it. That's West Chester. Click, and hold your left mouse button down just south of the yellow areas. Still holding the button down, move your mouse up and to the right of the yellow areas. You are describing the rectangle you wish to zoom in on. When you have the rectangle that you want to see more closely, release your mouse. You can now see more detail.

One more technique is very helpful for getting us quickly repositioned on the map although it does not appear on the Main Toolbar. What if we wanted to get back where we started, looking at all of Chester County? Move your mouse over the map and then right-click on the map. On the pop-up, select View Entire Layer, (see image below) then select All Layers and then click Ok. This repositions your view so that you can see all the features on any of the layers on your map. You should now see all of Chester County, nicely centered in the map window.

Zoom back out to all of Chester County using any of the techniques you just learned.

Select Tool. One tool we will be using all the time is the select tool. This tool allows us to pick up an object on the map. We can then move it, delete it, copy it or change its properties. Select the Select Tool by clicking on it on the tool bar. The Select Tool will then appear sunken. It is the active tool. Now click the text on the map that says "Henderson High School." It will turn bright red to show that you have it selected. Now click the text again, this time holding your mouse down. Now move your mouse. You are now moving the text. Move it so it appears below (south of) the dot that represents the school. Now release the mouse button. Where you put the text is not important; just get some experience picking something up, moving it and then releasing it. Once you release the text it will still stay red, showing it is still selected. To unselect it, simply click out in the empty area of your window, where no features are.

Another use of the Select tool is to edit something. Select the text that says Henderson High School again. No double-click it. You now have a window open where you can change the font name, style, size, color and also edit the actual text. Click cancel to back out of edit mode.

Part 2. Tables, Glorious Tables!

We will now move to that aspect of a GIS which distinguises it from a mere digital map. The key characteristic of a GIS is that the map features are linked to a table. Every feature in the map, whether it is a school, a customer, a road segment or a census tract, is linked to a record in an attribute table. That record holds information about the feature, such as how many students attend a school, how many households are in a census tract, how many square feet of leasable area a store has, and many other sorts of information. The possibilities are almost unlimited. Anything that can be stored in a spreadsheet can be connected to a map feature.

Let's explore the table that goes with our high schools layer. In MapInfo, click Window, on the menu. Then select New Browser window. (We're not sure why MapInfo calls it a browser, it's really just a way of showing tabular information.) In the list that opens (see image below) click on high_schools and then click Ok. This opens the table that goes with the map's high schools layer. If one of your tool bars is in the way move it.

You should now see a spreadsheet-like document. The rows (horizontal) represent individual schools. The columns (vertical) represent the sort of information we are keeping on each school, such as its name, the address, student enrollment, etc.

How many schools were on our map? In fact there were 16 dots on the map, and 16 entries in this table. This information is shown in the lower left corner of the table; it will say 'records 1-16 of 16. Each dot on the map has an entry in the table. This means that we not only know where the school is located, we also know its street address, its zip code and the student enrollment.

Click on the white box to the left of the any of the schools' names in the table. The box will turn solid black. (See image above.)

Now let's go back to our map. Here's how to move between maps, tables and layouts in MapInfo. On the menu select Window and then at the bottom click the item that is your map window. It will be numbered "1," since it was the first thing opened and it will have the word Map at the end.

Look at your map. One of the high schools will appear differently than all the others. It will be drawn with aqua around its symbol. That is the school you selected in the table. They are one and the same! Again, this is the central distinction between a map and a GIS. In a GIS, each mapped feature is also connected to a table. The table contains information of particular interest to us—information we will use to make better business decisions!

We will be using the connection between map features and table entries throughout this course. 

Part 3. Creating A Layout

Once you've created a map, you'll generally want to print something out for others to see. You'll need to create a layout.

For this lesson, you'll modify an existing layout. In the next lesson you'll create a layout from scratch.

Let's open an existing layout. Click on Window on the menu bar, go down to item 3 in the list (it is named Layout) and then release your mouse. You are now in a Layout Window.

Let's make sure we are all looking at the entire layout. On the menu, click Layout and then View Entire Layout. You should now see your entire page. The page size for this map is 11 inches wide by 8.5 inches tall.

The largest item on your page layout is the map frame. This tells MapInfo to put your map on the layout, and also how large it shojuld be and where it should be placed.

We will now use the Drawing Toolbar (see image right) to modify some of the objects on our layout. As with the Main Toolbar, you can hover your cursor over each of tools; words will appear that show what each tool does. Take a minute to hover over the Drawing tools to see what they do.

Let's add some Text to our map layout. Click on the text tool on the Drawing Toolbar. Now click on the page near but above the text that says Geo325-X. Move your mouse away from the place you clicked. See the blinking cursor? You can now start typing. Type your name.

Now let's change the appearance of that text you just added. Click on the Select tool on the Main toolbar. Now click the text you just added to select it. It will turn red. Click on the Text Style tool. In the dialog box that opens, set the point size to 24 and select Bold. Click Ok.

Let's fix the map title. See the text that starts "A Map Title Should ...". Let's edit that text and give our map a good title. Double click on the text. Edit the text and give your map a good title, such as "High Schools in Chester County."

Using the Drawing Toolbar, let's modify the class section. Delete the "X" and make that say your section, e.g., 1, 2, 3, etc. Add today's date on underneath the section.

Now tidy up the text in the lower right corner of the map (your name, section, date, etc.) This information is less important than the title of the map, so it should be smaller, maybe a 10 or 12 point. Move the descriptive text and graphic objects to the lower right corner of the page, in the following order from top to bottom: north arrow; scale bar; your name; the class and section; today's date and the lesson number. Set the text font size to the smaller size. Align them nicely; either left- or center-justified. You can't easily move the scale bar in MapInfo. Simply place the other objects around it, in the order given. Center them nicely on the scale bar.

Before we print, turn off the layer that shows water features. Also make sure that streets are drawn above the urban areas. Hint: you are currently in a layout, where graphics and text can be added to your page. To turn layers off and on, you'll need to go back to your Map. Remember how to get to your map?

Print Your Work. Once your map if formatted to your liking, you can print by selecting File > Print and clicking OK in the Printer Dialog Box. Wait a minute or two; if your map does not print to one of the printers in the rear of the lab, ask a lab assistant for help.

Lesson documentation updated 06/02/08; Ellen Bryson.
The Center for Geographic Information Systems and Spatial Analysis at West Chester University