Eyes in the Sky II > GIT Web Course > Module 2 > Week 6 > Intro to Symbolization > Introduction to Symbolization in ArcGIS

Week 6: Following Rivers Through Time

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Intro to Symbolization in ArcGIS

Symbolization is the process of choosing how to represent the features on a map. The symbols we choose should help describe additional information about the features on the map. Poor symbolization leads to inaccurate, misunderstood, or even deceptive information, while effective symbolization helps to communicate information quickly and clearly.

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Download Geographic Data About Louisiana

Launch ArcGIS, Open the Louisiana Project File, and Add a New Layer

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Explore the Attribute Table of the Cities Layer

Each layer of a GIS project includes a database of information about its features. This information is presented in an Attribute Table, which is linked to the map features associated with that layer.

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Adjust the Color, Size, and Type of Symbol Used to Represent Features on the Map

06 Properties Window The Properties window in ArcGIS.

When you added the cities layer, you may have noticed that it was automatically assigned a color. This initial color choice for the data is random. Compare the color of the city dots to the colors in the other layers. You may find that there is not enough contrast between colors or that the cities came in with the same color as another layer, making them difficult to see. It may be necessary to change the color of the city dots. The symbols used to represent features in a layer can be modified in that layer's Properties window.


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Symbolize by Color

In the Properties window, click on the symbol button. In the Symbol Selector window, change the color of the cities to Brown. Select the following options:

  1. Right-click on the cities layer name in the Table of Contents .
    12 Right Click Cities
  2. When the Properties window opens, the Symbology tab is selected and Single Symbol is the default. Click on the Symbol button.
    13 Click on Symbol Button
  3. Click on the black Circle1 in the . 13 Click on Symbol Button
  4. Under Options, click on Color and change the color to Cocoa Brown by selecting it from the Color Palette.
    17 More Colors Under Options, click on Size and change the size to 6.
    22 Triangle
  5. In this map, Louisiana cities are now represented by Brown dots.
    16 Louisiana brown dots

Symbolize by Symbol Type

Instead of using dots to represent cities, you may want to choose a different type of symbol. Right click on the cities layer, and in the Properties context menu, change the symbol style of the cities to Triangle. Select the following options:

Right click on the Cities layer and in the context menu, click Properties. In the Symbology Tab click Symbol. Change the symbol shape from Circle1 to Triangle1.
22 Triangle
In this map, Louisiana cities are represented by Brown Triangles. 25 Louisiana Brown Triangles

In the Properties window, choose a symbol that you think makes sense for representing cities. Experiment with other choices in the Symbol Selector window.

In this map, Louisiana cities are represented by Brown Squares.
27 Louisiana Brown Squares

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Symbolize by Size

If you chose triangles as your new symbol for cities, you may notice that they appear smaller than dots. In this case, you may wish to increase the size of the symbols. In the Properties window, change the size of the symbol of the cities to 10. Select the following options:

In the Symbology tab in Properties, click on Symbol and click on Size and change to 10.
28 Brown Triangles
In this map, the size of the symbols representing cities has been changed to 10.
29 Louisiana Brown Triangles

In the Symbology tab, choose a size that you think makes sense for the symbol you are using to represent cities. Experiment with other choices in the Size option.

In this map, Louisiana cities are represented by Green Squares that are 8 points in size.
30 Louisiana Green Dots
Movie Icon

Click on the movie to open up the movie in the SERC Media library. Then click its name to play it. Close the window when you are done.

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Add Meaning to the Symbols to Differentiate Between the Features on the Map

At this point, every city in Louisiana is represented by the same symbol and with the same color. The residents of these communities will be quick to tell you that Louisiana's cities are not all the same! Using appropriate symbolization, you can communicate information about the cities beyond their locations.

In the Properties menu, Symbology tab, change the symbolization for the cities using the following options:

Now each city has its own color. You have taken one step towards differentiating the data in the map. However, as you can see, the map now looks like it was sprinkled with confetti. Although you have given each city a unique color, this is probably not the best way to display this information, as it is overly busy and somewhat distracting to view. In the Introduction to Classification, section you will learn a more sophisticated way to add meaning to the cities layer.

Last, name the layer in the Table of Contents something unique to this project, such as Louisiana Cities.


Click the layer name cities in the Table of Contents. It will be highlighted. Click cities a second time and type Louisiana Cities or a name of your choice into the cities layer name.
33 Rename Louisiana Cities

Movie Icon

Click on the movie to open up the movie in the SERC Media library. Then click its name to play it. Close the window when you are done.

loading the player

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Label Features of Layers

Sometimes symbols are not enough information and it is preferable to actually label the map with words or numbers. In this example, we will label the Parishes by name. (A parish in Louisiana is equivalent to a county in other states.) Movie Icon

Click on the movie to open up the movie in the SERC Media library. Then click its name to play it. Close the window when you are done.

loading the player

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Explore More If You Have Time



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Movies on this Page

How to download movies

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Flash Video Versions

Download these versions to play on your computer. You'll need an appropriate movie player to view the file, such as Flash Player, Real Player (Mac / Win), or Adobe Media Player.

Movie Icon Changing Symbols in ArcGIS

Movie Icon Unique Symbols in ArcGIS

Movie Icon Labeling Features in ArcGIS

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iPod Versions

Download these version to play on your iPod or iPhone.

Movie Icon Changing Symbols in ArcGIS

Movie Icon Unique Symbols in ArcGIS

Movie Icon Labeling Features in ArcGIS


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