Week 6: Following Rivers Through Time

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Intro to Symbolization in My World

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

  • Right-click (Win) or control-click (Mac) the link below to download the zipped file to your computer.
  • LouisianaMW.zip (Zip Archive PRIVATE FILE 33.6MB Jun13 10)
  • Unzip the file. A folder called LouisanaMW will be created.
  • Move the entire LouisanaMW folder into the My World data folder. (Path: Applications/My World /data/LouisianaMW)

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

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  • Launch My World by double-clicking its icon on your desktop or by clicking its icon in the Dock (Mac) or Launch Bar (Win).
  • Choose File > Open Project..., navigate to Applications/My World /data/LouisanaMW, select the LA_Rivers.m3vz file, and click Open.
    5 LA Rivers project open
  • A map of Louisiana is displayed when the project opens. Parishes are shown in tan and the Mississippi River is blue.
  • In Visualize mode, select File > Import Layer from File add layer from file , navigate to the LouisianaMW folder, select cities.shp, and click OK.
  • My World will ask if the projection is in Latitude and Longitude, it is, so click OK . This layer maps cities in Louisiana and should now be the top layer on your map. Note: The cites layer is automatically turned on when it is added.
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Explore the Table of Layer of the Cities Layer

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

  • Click the Louisiana Cities layer in the Layer List to make it the active layer. Then click the Show table of the Active Layer button. Scroll through the fields (columns) and the data records (rows) in the Table of Layer.
  • What type of data is given about cities?
  • How do you find out what the field names mean?
  • Close the Table of Layer "Louisiana Cities", window.
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Adjust the Color, Size, and Type of Symbol Used to Represent Features on the Map

10 edit appearance The Edit Appearance window in My World .

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 Edit Appearance window.

  • To open the Edit Appearance window for the Louisiana Cities layer, double-click on the Louisiana Cities label in the Layer List. The Edit Appearance window opens, move it so you can see both it and the map at the same time.

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Symbolize by Color

In the Edit Appearance window, change the Louisiana cities to Brown circles. Select the following options:

  • Choose Shape by: Uniform
  • Shape Circle
  • Size 20%
  • Color Brown
  • Click OK and click Apply

In the Edit Appearance window, choose a color that contrasts well with the map. Explore the built in color options as well as the custom ones in the color chooser windows.

Symbolize by Symbol Type

Instead of using dots to represent cities, you may want to choose a different type of symbol. In the Edit Appearance window, change the symbol style of the cities to Triangle. Select the following options:

  • Choose Color by: Uniform
  • Shape Triangle
  • Color Brown
  • Size 20%
  • Click Apply and Click Close

In the Edit Appearance window, choose a symbol that you think makes sense for representing cities. Experiment with other choices in the Style drop down menu.

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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 Edit Appearance window, change the size of the symbol of the cities to 10. Select the following options:

  • Choose Color by: Uniform
  • Shape Triangle
  • Color Brown
  • Size 40%
  • Click Apply and click Close

In the Edit Appearance window, choose a size that you think makes sense for the symbol you are using to represent cities. Experiment with other choices in the Size Range drop down menu.

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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 Edit Appearance window, change the symbolization for the cities using the following options:

  • Choose Color by: AREANAME
  • Shape Circle
  • Colorscheme Random
  • Size 20%
  • Click Apply and click Close
  1. Double-click on the Louisiana the cities label in the Layer List. Then select Edit Appearance. Click the Color tab, then click the Choose Color by: AREANAME. In the Colorscheme drop down menu, choose Random.
    23 area name random
  2. This polka dot map of cities in Louisiana is the result.
    24 area name random on map

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.


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Create a New Annotations Layer to Label Features of a Layer

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.) To make a labels layer in My World, change to Edit mode and create a new annotations layer.
26 the edit tab

  • Return to Visualize mode, to check your new layer's appearance. If needed, you can do further editing of the layer's appearance in this mode.
  • Quit My World and do not save the project.

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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 My World

    Movie Icon Unique Symbols My World

    Movie Icon Labeling Features My World

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    iPod Versions

    Download these version to play on your iPod or iPhone.

    Movie Icon Changing Symbols My World

    Movie Icon Unique Symbols My World

    Movie Icon Labeling Features My World


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