Week 5: Monitoring Invasive Species
Intro to My World GIS
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Intro to My World GIS
My World GIS is a downloadable, Geographic Information Systems (GIS) tool for exploring geographic data. It is possible to combine point, line, polygon, and image data in a GIS such as My World. My World comes with a large selection of built in data that can be used in projects. My World can save and open projects, so work can be shared between users, or between school and home. My World can classify and symbolize shapefiles, display image data, project on-the-fly shapefiles stored in decimal degrees, and use data distributed over the Internet from ArcIMS services from the Geography Network, or other hosted ArcIMS sites.
It is also possible to use My World with data that is downloaded from a GPS unit to create custom layers of information that then can be related to scientific and other types of data. GIS Data is often freely available over the Internet from cities, counties and federal organizations such as the National Park Service (NPS) and the United States Geologic Survey (USGS).
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The My World Toolbar
The My World toolbar contains a variety of tools for analyzing and manipulating geographic data. You will learn about the tools as you use them.
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Download Geographic Data About Invasive Species
- Right-click on the PC or control-click on the Mac to download the zipped file below.
Zipped file of Invasive_Species lesson and data (Zip Archive 50.7MB May13 10) - Unzip the file. A folder called Invasive_speciesMW will be created.
- Move the entire Invasive_SpeciesMW folder to inside the Data folder of My World.
The navigation path should be - path: .../My World/data/Invasive_SpeciesMW
Explore a GIS Map
- 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 .../My World/data/Invasive_SpeciesMW folder, Open the folder and select the file inv_spc.m3vz . Then click Open.
- Choose File > Open Project
- Navigate to .../My World/data/Invasive_SpeciesMW
- Open the Invasive_SpeciesMW folder.
- Select the file inv_spc.m3vz. Then click Open.
When the project opens, a world map is displayed. Countries are shown in grey and lines of Latitude and Longitude are drawn at 10 degree intervals.
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Zoom in and out
- Use the Zoom In
tool to click once on South America. - Click once on the Zoom to All tool
to take the map all the way back out to a full view.
NOTE: This is a nice trick if you get lost and just want to start over again. - Continue clicking on the map with the Zoom In
tool. The tool automatically centers the zoom around the area where you click. How far can you zoom in?
- Use the Zoom Out
tool to zoom out several clicks. How far can you zoom out? - When you are done exploring zooming, click the Zoom to All
tool.
- Click and drag out a rectangle across Africa with the Zoom In
tool. Notice how this allows for more precise zooming.
- Click the Zoom to All
tool to return to the full map view.
- Likewise, you can also use the Zoom Out tool to drag out a box. It is possible to keep zooming until all you see is just a tiny speck. Sometimes this might happen unexpectedly, especially if you click and drag out a tiny box with the Zoom Out tool. Experiment zooming in and out so you get a feel for how this works.
Map as a tiny speck
- Two other buttons help you navigate on screen. They are the Zoom to Previous Extents
and Zoom to Next Extents 
buttons. Try zooming in and then experimenting with these buttons. The Zoom to Previous Extents button lets you go back to a previous level of focus. Both of these buttons give you unlimited zooms back and forth between levels.
- Zoom in around the Azores
- Return to previous
- And back again.
- Zoom in around the Azores
- When you are zoomed in, you can use the Move Map Tool
tool to adjust your view. Click and hold the Move Map Tool and drag your mouse to center your map on another place. - When you are done exploring zooming, click the Zoom to All
tool.
The map is centered on South America after one click with the Zoom In tool.
This view shows the map zoomed back to the full extent of all the layers.
Map zoomed in all the way. Notice the 1:1 numbers circled at the bottom.
As you zoom closer and closer on image (raster) data, you eventually see "pixels." A lot of GIS data is vector-based so you can continue to zoom in nearly infinitely.
The reference numbers at the bottom of the map are the scale of the map represented as a ratio or a fraction. They refer to the level of magnification. At the maximal level of zooming in you see 1:1 as the magnification. In other words, 1 inch on the map would be equal to one 1 inch in reality. As you zoom back out, watch the numbers in the ratio change. When you put the map back to full view, the scale reads 1:174,230,742. So this means that 1 inch on the map represents 174,230,742 inches, or approximately 2,800 miles.
Here is an example of the map zoomed out.
Click and drag a box around Africa.
After zooming, the map shows Africa in the center.
After zooming, the map shows Africa in the center.
Click on the movie to start playing.
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Find latitude and longitude
Move the cursor across the map to discover changes the values and how they relate to Longitude and Latitude.
- Start at the far left side of the map and move your cursor horizontally to the right, all the way across the map. Observe how the Longitude coordinate changes. The Longitude and Latitude coordinates are shown in the lower left corner of the map. What happens to the Longitude values?
The Longitude values start large with a W (for West) and decrease as you move right, reach zero, switch to East and then become larger values again.
- Move your cursor vertically from the bottom to the top of the map and observe how the Latitude coordinate changes. What happens to the Latitude values?
The Latitude values start South and decrease as you move up, reach zero, and then become North values and increase as you move away from the equator.
- Which values are longitude? Which are latitude? How are south and west indicated?
In this case, the cursor is hovering over southern Alaska.
Notice in the lower left corner of the map view; Longitude: 150.28772 W Latitude: 63.1341 N
W is the Longitude and N is the Latitude.
North and West are indicated with capital letters.
- Just for fun, try to find 0, 0. (Hint: it is near Africa)
The cursor is hovering close to 0,0 in the image.
Click on the movie to start playing.
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Discover How the Layers Build the Map
A GIS map — is made of layers of geographic information connected to specific places on Earth. GIS layers can be global, regional, or local. They can represent 1) points, such as cities, 2) lines, like rivers and roads, or 3) geographic areas such as states and countries.
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Turn layers on and off
To turn a layer on or off, click in the check box next to the name of the layer. The layer will then be displayed on the map and a symbol that looks like an eye will be displayed in the box.- Click the checkbox next to the U.S. States layer to turn it on. A layer that is on has an eye in this box.
- Currently, the legend of the U.S. States layer is off. To show the legend, click the L symbol to the left of the layer checkbox. Then use the Zoom In
tool to zoom in on North America by clicking on the map.
The legend of the U.S. States layer is now on and the map view is zoomed into North America.
Explore moving Layers in the Layer List
To the left of the map view is a listing of Layers, called the Layer List.- In the Layer List, select the U.S. States layer by clicking and holding its name. Drag the U.S. States layer down the list and place it at the bottom.
Click and hold on the U.S. States layer in the Table of Contents. Drag it down to the bottom of the list.
This is what the map looks like with the U.S. States layer at the bottom.
- What has happened to U.S. States layer?
The layer is no longer visible. This is because it is now beneath the Lines of Latitude & Longitude and Countries layers. If a layer is opaque, as this one is, it can hide other layers. So, in this case, the Countries layer has now hidden the U.S. States layer. - Turn off the Countries and you will be able to see U.S. States again.
In the map below, U.S. States are hidden by Countries.
Turn off Countries and U.S. States are now visible again.
In this map the Countries layer has been turned off.
Each layer in a GIS builds the map. The data that make up the layers are shown as either points, lines, or polygons. These layers come from shapefiles, a standard GIS data format. (It is also possible to add images to a GIS.) The layers are drawn from the bottom to the top as they appear in the Layer List. If not positioned properly, it is possible for some layers to cover up others. In general, polygons should be placed at the bottom, while lines and points should be arranged near the top.
Click on the movie to start playing.
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Understand Which Layer You Are Working With
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When you click on the name of a layer, it is highlighted and becomes active, which tells My World to pay attention to it. Understanding the difference between a layer that is turned on and one that is active can save you time and help prevent frustration. A layer may be on or off as well as active or not. Layers that are on have a checked box while layers that are active are highlighted white with a yellow line around them. More than one layer can be on and but only one layer can be active.
Turn on and make the U.S. Rivers layer active.
- To turn on the U.S. Rivers layer, click once in the box next to its name.
The U.S. Rivers layer is now on.
- To make the U.S. Rivers Layer the Active layer, click once on its name in the Layer List. It is now highlighted.
The U.S. Rivers layer is now the active layer.
Zoom to Active Layer
Zoom to the active U.S. Rivers Layer.- To zoom in on the U.S. Rivers layer, click the Zoom to Active Layer
tool in the toolbar.
This shows the view zoomed in, after clicking Zoom to Active layer.
Click on the movie to start playing.
loading the player
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Investigate the Geographic Data Behind the Map
What sets a GIS apart is the database of information linked to each layer drawn on the map. This makes it a powerful tool for decision-making and science. The data for each feature displayed on the map can be found in the Table of Layer. This table, or database, contains the geographic records in horizontal rows. The vertical columns, or fields, are the attributes of the data.
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Examine the Data in the Table of Layer
Select several U.S. Rivers to connect rivers with their river systems.
- With the U.S. Rivers layer on and Active, select the Table of Layer
button.
Open the Table of Layer of U.S. Rivers
- In the Table of Layer, click on the NAME Arkansas River. Notice it becomes highlighted in blue in the Table of Layer and in yellow on the map.
- In the table below the Arkansas River is selected.
- To select it on the map, click make selection from rows, click OK.
- Name the selection "Arkansas River" and click OK.
- It will now be in the layer name as a selection and highlighted on the map.
- In the table below the Arkansas River is selected.
- Try this with several rivers. The Table of Layer brings up the records of all the rivers and shows you all the information that is available for each record. For example, you can see which river system varioU.S. Rivers are in. The Arkansas River is in the Colorado River System.
Select all the rivers in the Colorado River System.
- Open the Table of Layer of U.S. Rivers and click once on the column that holds the data for the SYSTEM field. This sorts the data in descending order. Scroll down the list to where you see the 4 rivers on the map that are in the Colorado System.
- Open the Table of Layer of the U.S. Rivers layer.
- In the table, click once on the column that holds the data for the SYSTEM field, the data will be sorted in descending order.
- The rivers are now sorted by their system.
- Open the Table of Layer of the U.S. Rivers layer.
- Hold the shift key and click on the first and last of these 4 rivers to select the rivers as a group.
- Then click the "Make Selection from Rows" button, name your selection, "Colorado System".
- Once you have made several selections, close the Table of Layer. Check the selection name in the Layer List and click on the Delete Selections button. It looks like
scissors. Be careful not to delete a layer!
The Colorado River System is selected in the Table of Selection and highlighted in yellow on the map.
Find Features of Rivers with the Get Information Tool
Find rivers on the map with the Get Information tool 
- Click on the Get Information tool in the toolbar to select it. Use the Get Information tool to click on a river on the map to select it. When you click on a river a results window will open with the name of the river.
- Click on several U.S. Rivers to identify them.
- At the end of your session, quit My World. Do NOT save changes that you have made to the map.
In this example the Rio Grande River has been selected.
Click on the movie to start playing.
Find Tool Movieloading the player
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Explore More if You Have Time
Explore the Attribute Tables of other layers in the map to see the different types of data linked to the map layers.
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Additional My World ResourcesInstructional Materials for My World
Getting started with GIS
Help Center for My World
Geospatial Technology Curriculum Page
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Movies on this Page
How to download movies
- Click the link to go to the SERC media library listing for the movie. The record will open in a new window.
- On the SERC media library page, right-click (Win) or control-click (Mac) the link (below the movie on the Flash version pages) to download the movie file to your hard drive.
Look below the movie window for the file download link.
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.
Zooming My World
Latitude and Longitude My World
Layers My World
Active Versus On My World
Investigating Database My Worldtop of page
iPod Versions
Download these version to play on your iPod or iPhone.
Zooming My World
Latitude and Longitude My World
Layers My World
Active Versus On My World
Investigating Database My World
