Part 2—Launch My World and Explore Land Use Data
Step 1 Launch My World GIS
- Launch My World GIS by double-clicking its icon on your desktop or by clicking its icon in the dock (Mac) or Launch Bar (PC).
- Choose File > Open Project and navigate to the file, Wetlands.m3vz. Select it and then click Open.
When the project opens, a World map displays. It shows a map of Land Cover Classification with the outlines of Countries and U.S. States overlaid on top. Layers not visible on the map include: Macclenny, Florida, NWI Macclenny Wetlands, Florida Interstate 10, Major Highways, U.S. Counties, U.S. Cities, Macclenny Wetlands Topo, and Income and Employment.
Step 2 Locate the United States, Zoom In, and Explore Land Cover Data
Explore Active LayersTo the left of the map view is a listing of Layers, called the Layer List. In the Layer List, notice the checkbox to the right of the name of a layer. Click once in this box to turn a layer on and make it visible. Notice that when a layer is on, it is visible and there is an eye in the checkbox.
- Turn on U.S. Cities by clicking in the box next to its name. Layers that are on (visible) have an eye in the check box.
- Notice that as you turn on a layer there is a legend for that Layer. To turn a legend on and off, click on the L symbol next to the words "Category List".
- Click anywhere in the box next to the name of a layer. The box will turn white and have a yellow highlight. This indicates that this layer is the Active layer. In the image below, U.S. Cities layer is the active layer and the Legend for the U.S. Cities is on. The radio button in the highlight mode shows that a selection, "U.S. Cities with Population > 500,000", is being displayed on the map. To see all U.S. Cities, click the All (highlighting off) radio button.
- Make U.S. States active, and click the Zoom to Selection layer button. Your map will zoom in to the extent of this layer.
- Click on the Zoom to Previous Extents button and re-center your map on the World.
- Turn off the legend for U.S. Cities.
- Make U.S. States the active layer, turn on its Category List (legend) and use the legend, to the right of the map, to find Florida.
- Make sure the Highlight Mode is set to Color Selected (Yellow). Click once on the name Florida in the Legend for the U.S. States. Florida will be selected and highlighted on the map.
- Click the Zoom to Selection button to zoom to the extent of the selection, Florida.
- Once you have zoomed in to Florida, turn off the highlighting by clicking the All (highlighting off) radio button. (It is located in the Layer List under the layer name.)
Explore Moving Layers in the Layer List
- Turn on the U.S. Counties Layer.
- In the Layer List, select the U.S. Counties layer by clicking and holding its name. Drag the U.S. Counties layer down the list and place it below the Land Cover TIFF layer.
- Click and hold on the U.S. Counties layer in the Layer List.
- Drag it down the list. Place it below the Land Cover TIFF layer and release your cursor. U.S. Counties layer is now invisible.
- Turn off the Land Cover TIFF layer and the U.S. Counties layer is visible again. It was hidden beneath the opaque Land Cover TIFF image.
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 as is shown here.) The layers are drawn from the bottom to the top as they appear in the Layer List. If not positioned properly, some layers may cover up others. In general, images and polygons should be placed at the bottom, while lines and points should be arranged near the top.
- Click and hold on the U.S. Counties layer in the Layer List.
- Return the U.S. Counties layer to just above the U.S. States layer and turn it off. Practice turning other map layers on and off, and moving them up and down in the Layer List.
- Make sure the Land Cover TIFF is on and zoom out to the full extent of this layer.
Step 3 Zoom into North America and Use the Link tool to Explore Land Cover Data
- Select the Zoom In tool. Your cursor will now look like a magnifying glass with a plus in it.
- Click and drag a box around North America with the Zoom In tool. Release the tool and the map will center on your selection.
- Click on the Link tool. With this tool selected, click on the flag icon in the lower left corner of the map. Then click on the name of the legend, Project:lcc_key.jpg.
- A new window will open, with pictures and the color code for the land cover types. Use the scroll bar on the legend image to move the picture legend up and down.
- Use this information and the Zoom tools to explore the map.
- Make sure the U.S. Cities layer is on. On the layer's name in the Layer list, click once on the Highlight Mode turn-down triangle. Click on the radio button next to the selection "U.S. Cities with Population > 500,000". Consider the relationship between Land Cover and Land Use and large cities.
- 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.
- When you are finished exploring, turn off (uncheck) the Land Cover TIFF.
Step 4 Zoom into Florida and Locate Jacksonville, Florida
- Using the Zoom and Pan tools, zoom in (or out) until you see Florida and the Southeastern U.S.
- Click on the Analyze Tab to select Analyze Mode.
- In the analysis window, choose Select... > By Value. Select Records from: U.S. Cities whose name contains "Jacksonville".
- The Result Name: box will display Untitled. Click OK and a default result name will appear in a pop-up box. Accept the default result name by clicking OK. The result, "Name contains 'Jacksonville'," will be displayed as a selection listed under Highlight Mode in the U.S. Cities Layer.
- Notice that multiple cities have been selected. Open the table of the selection and find Jacksonville. Click on its name in the table to select it. With Jacksonville, FL highlighted in the table, choose the larger of the two cities and click the Make selection from Rows button.
- Jacksonville should be a single purple dot in Northeast Florida.
- Zoom in closer to Jacksonville.
Step 5 Add the Local Land Use Data and Edit its Appearance
- In Visualize mode, choose File > Import Layer from File and locate the .shp file in the unzipped folder that you downloaded from the WebGIS website at the end of Part 1. Single click to select the file, Valdosta.shp, and then click Open.
- The Check Projection window asks if your data is in Latitude and Longitude which it is, so click OK. My World GIS imports the shape file, places it on the map and saves a copy in the My World "data" folder on your computer.
- The new data layer should now be visible on the map and in the Layer List. Make it the Active layer and click the Zoom to Active Layer button in the toolbar.
- You will see that the layer includes data from an area in northern Florida. The map now displays the Valdosta Land Use data (valdosta.shp). In the Layer List double click on the valdosta.shp layer. (Note: your color may be different than in the image below.)
- With the new layer (valdosta.shp) the active layer, choose Layer > Edit Layer Appearance... In the Edit Appearance window, choose the following settings on the Fill Color tab:
- Choose Fill Color by... LUCODE.
- Colorscheme: "Rainbow".
- Transparency about 50%.
- Classify by Natural Breaks. Change the Minimum to 11 and Maximum to 92 (this coincides to the Level II land use code numbers).
- Click the Outline Color tab and change the transparency of the Outline to 70%.
Step 6 Save the Project File and Quit My World
- Now that you have added the new data, choose File > Save Project As... and name your project Wetlands_Part2, or some other unique name. Then click the Save button.
- Quit My World GIS.
Wetlands_Part2.m3vz ( 20.7MB Oct9 10)
Right-click (PC) or control-click (Mac) the link above to download the file.