Geography 281 Map Making with GIS Project Two: Map Design Issues in ArcMap

Transcription

1 Geography 281 Map Making with GIS Project Two: Map Design Issues in ArcMap This activity provides an introduction to the map design process. It takes you through a typical sequence from the initial decision to create a map to the completed product. Along the way it illustrates how you can use visual variables (color hue, color value, size, shape, and texture) to enhance your figure-ground contrast; thus giving depth to your flat map. In addition, you ll need to consider: Intellectual hierarchy within a map that highlights the important data and minimizes the importance of the supporting data. Visual hierarchy that maximizes figure-ground relationships. The first part of the activity guides you through the steps and decisions needed to create a map illustrating the spatial relationship between interstate highways and major cities in the lower 48 states. The second part lets you apply what you've learned to create a similar map for the state of Texas. In addition, we will be using another file storage method- file geodatabase. The data needed for Project 2 is located in the \\Geogsrv\Data\Geog281\Proj2 directory. Project 2 files: Description: Feature Type: Texas.gdb File geodatabase with Texas related files texas feature class Texas base map polygon tx_intrst_hwy feature class Texas highways line tx_major_cities feature class Major cities in Texas point US48.gdb File geodatabase with US 48 related files us48_intrst_hwy feature class U.S. highways line us48_major_cities feature class Major U.S. cities point us48_states feature class Lower 48 states base map polygon Before You Begin Here are the major steps involved in creating your map: Step 1- Identify Purpose of Map a. Who is the user? b. What spatial relationship is being conveyed? c. What is the output? d. What level of detail is needed? Step 2- Identify Data Needed a. How many variables are you mapping? b. What background layers are needed? c. Obtain the data sets and copy them to your workspace. Step 3- Design the Map using ArcMap a. Create a new map document file. Data portion b. Add layers to a Data View. c. Set map projection and scale. d. Assign symbols to layers. e. Add text to map. f. Final map edit. Layout portion g. Add cartographic elements to the Layout View. h. Adjust cartographic elements. i. Send the map to the output device. j. Save your work. Step 4- Get Feedback a. Make necessary changes. Step 1- Identify Purpose of Map Your goal is to create a map that illustrates how the interstate highway system converges on major cities in the lower 48 states. You are creating this map to accompany a term paper for another geography class and will present the final map in landscape orientation in a PDF document.

2 Step 2- Identify Data Needed A map such as this requires two thematic layers (major cities and interstate highways) and one background layer for orientation (U.S. 48 states). If you add additional layers (i.e., local roads or rivers) you risk cluttering the map and drawing attention from the relationship you want to illustrate. The more information you put on your map, the more difficult it is to establish a sharp visual contrast between the figure (thematic layers) and the ground (orientation information). Step 2a. Obtain the Data Sets and Copy Them to Your Workspace The data you need are available on the Geogsrv server: Run Deltemp to clear out your workspace. Copy the Proj2 folder from \\Geogsrv\Data\Geog281 directory to the C:\Temp directory on your local machine. Note: Project 1 included instructions on how to copy data using ArcCatalog outside of ArcMap. This week we will copy the data using File Explorer. Copying Data from Server using the File Explorer: Open File Explorer ( Windows Explorer). Navigate to the \\Geogsrv\Data\Geog281 directory. Right Click on the Proj2 folder and select Copy. Navigate to the working directory ( C:\Temp) Right Click and select Paste. This will copy all of the data from the server to the working directory. Start ArcMap. From the Start menu, choose Programs ArcGIS ArcMap. If the Getting Started dialog box appears, select New Maps (on the left panel), and Blank Map under My Templates. Click OK. Step 3- Design the Map using ArcMap Now that you've assembled your data, you are ready to create your map in ArcMap. Project 2 does NOT start with an existing map document file; you will need to create one. Step 3a. Create a new map document (.mxd file) From the Main Menu, select File Save As. If necessary, navigate to C:\Temp\Proj2\MapDocuments directory. Enter the File name Proj2 and press Save. Data Portion Step 3b. Add Layers to the Data View To add layers: On the Standard Toolbar, click on the Add Data ( ) button. You will need to create a folder connection to your data. On the Add Data dialog box, select the Connect to Folder Icon shot to the right.. See screen Navigate to the C:\Temp directory and select OK. Note: This adds a connection to your data directory. From here, navigate to the Data\US48.gdb file. 2

3 Click on us48_major_cities. Hold down the Control key and using the left mouse click to highlight the two other feature classes that begin with us48_. Press Add. ArcMap draws layers from the bottom layer in the legend to the top. It usually places point-feature layers on top, line-feature layers below the point feature layers, and polygon-feature layers at the bottom. Step 3c. Set Map Projection and Scale Because the data for this project have already been converted into an appropriate coordinate system, you don t have to make any changes to the projection. You may need to use the zoom and pan functions to re-center the map or to change the map scale so that the map fits properly within the Data Frame window. Step 3d. Assign Symbols to Layers The default symbols provided by ArcMap when you first add a layer to your Data View are rarely the optimal symbols for conveying your map's message. Only you know what you want the map to say and only you can decide which visual variables (color hue, shape, size, texture, color value) you should use. ArcMap provides you with a vast range of symbol types and options. Here are examples of some of the principles you can use to help narrow down your choice: Background Information- States The US48_states layer provides users with background location information. This layer is not the main focus of the map, but instead is a supporting data layer. Therefore, the visual variables symbolizing this data should not pop more than the highway and city data. Supporting data plays several roles; it gives users a frame of reference for the other data used in the map, it provides a visual contrast within the map, and it provides map-background contrast between the map and the white page on which the map is composed. Here are some of the principles you should apply in order to achieve intellectual and visual hierarchies within the map: Select a light background color that establishes visual contrast with the cities and roads but that also stands out against the white page. Avoid high-intensity colors that might dominate the map when used across a large area such as the entire U.S. Select a lighter color for state boundary lines to provide visual contrast with the highway lines while still providing a sufficiently sharp edge to the mapped area. Now let's create a symbol that meets these criteria: In the layer list, click on the us48_states layer. Then right click the layer name and choose Properties. Click on the Symbology tab. Under Symbol, click on the colored default polygon symbol. See screen shot to right. Highlight the Yellow rectangle on the left of the dialog. Click on the down arrow next to Outline Color. Slide the mouse across the colors and select Gray 20%. Press OK twice. 3

4 Central Theme Information- Highways The highway layer is one of the central themes of the map; as such it should include more visual importance: Select a symbol that emphasizes the linearity and convergence of the highways. Choose a symbol color that stands out from the background. Avoid excessive line width that might detract from the linearity and hide too much of the convergence. Now create the highway symbol: In the layer list, right-click on the layer name us48_intrst_hwy and choose Properties. Click on the Symbology tab. Under Symbol, click on the colored default line symbol. See screen shot to the right. Highlight the red Highway symbol. Set the symbol Width to 1.5. Press OK twice. Central Theme Information- Cities The cities layer is also central to the spatial relationship you are trying to illustrate. If the symbol is too small and too similar in color to the freeways, the cities may disappear. If the symbol is too large and too bold relative to the freeways, the viewer may only see the cities and miss the pattern of freeway convergence. Choose a color, size and shape that enable the cities to stand out from background and highways (visual contrast) without dominating the highway pattern. Now create the cities symbol: In the layer list, right-click on the layer name us48_major_cities and choose Properties. Click on the Symbology tab. Under Symbol, click on the colored default point symbol. See screen shot to the right. Highlight the Square 2 symbol. Click on the down arrow next to Color. Slide the mouse across the colors and select the one named Apatite Blue. Set the symbol Size to Press OK twice. Note that each of these symbols is just one of many possible choices you might make. For now, don't worry too much about the color and symbol choices - we'll discuss them in more detail later in the course. 4

5 Step 3e. Add Text to Map At this point you need decide what text, if any, to add to the map itself (title and legend text will be added later). Since you are emphasizing the overall pattern among the cities and the highways, no individual features need to be identified. Adding text such as state names, freeway numbers, and city names would diminish the visual contrast among the mapped features by adding visual clutter to the background. For that reason, no text needs to be added to this map. Step 3f. Final Map Edit Look at the resulting map to see if it satisfies the criteria related to legibility, figure-ground contrast, mapbackground contrast, and hierarchical (both intellectual and visual) organization. Above all, decide if the map effectively communicates the spatial relationship between highways and cities. If problems exist - now is the time to fix them. Once you are satisfied with the map, then you can move to the Layout window to complete the map composition. Layout Portion Now switch to the Layout View where you can add a title, legend and other cartographic elements to your map. From the Main Menu, choose View Layout View. In the Layout View window, right-click outside the map page and choose Page and Print Setup. Under the Paper section, set the orientation to Landscape. Under the Map Page Size section, also set the orientation to Landscape and press OK. In the toolbar, click on the Select Elements tool. Click anywhere inside the map to select the map frame note the blue boxes. Press and drag the blue boxes to fit the map to the page. Note: you may need to drag the Layout Toolbar out of the way to the bottom corner of the window. Step 3g. Add Cartographic Elements to the Layout View At this point you need to decide what cartographic element frames need to be added. At a minimum, you need a title and a legend. For now, we'll skip the North Arrow, Scale Bar and other optional elements. First, add the legend: From the Main Menu, choose Insert Legend. Press Next Next Next Next Finish to select each of the legend defaults. Move the mouse over the newly created legend until you see the crosshairs cursor. Press and drag the legend to a position on the page below California and Arizona. If the legend text is illegible, press and drag on a corner of the legend frame to make the legend slightly larger. Click on a blank area outside the map page to remove the selection from the legend. For now, it s OK to accept the default legend. Later you ll learn how to modify the legend to make it more effective. Finally, add the title: From the menu, choose Insert Title. Replace the default title text with Major Highways and Cities and press Enter. Right-click on the title and choose Properties. Press the Change Symbol button. Set the Size to 24. Press OK twice. Drag the title to a new location that is centered over the map and evenly spaced between the top of the map and the top of the page. Click on a blank area outside the map page to remove the selection from the title. 5

6 Step 3h. Adjust Cartographic Elements If necessary, use the Select Elements tool to adjust the size, position and contents of the map, legend and title. Keep in mind the principles of legibility, visual contrast and balance among map elements. Also think about the map-background contrast between the individual map elements and the page. Specifically: Try not to crowd the elements too close together or too close to the page border. Don't leave too much white space between the elements. Make sure that the title and legend are legible. Don't let the size or position of the title and legend detract from the central focus of the map. Step 3i. Send the Map to the Output Device Once you are satisfied with your map, you will export it as a PDF document. From the Main Menu, choose File Export Map Select PDF (*.pdf) from the Save as type drop down box. See screen shot to the right. Save the PDF file in the C:\Temp\Proj2\MapDocuments folder. Note: you may need to navigate to this directory. Set the File name to Proj2. Select Save to export the map. In Windows Explorer, navigate to the Proj2\MapDocuments directory and view the PDF file. Everything should be displayed as it appeared in the Layout View. If something is missing, return to ArcMap and correct the issue. If you are satisfied with your map, proceed to Step 3j. Step 3j. Save Your Work Save the finished map to Proj2.mxd in the C:\Temp\Proj2\MapDocuments folder. Explore your data- Summer Road Trip While working on your map, you start thinking about next summer and decide to take a road trip along Interstate 10. Starting in Los Angeles, What cities would you pass while on your I-10 road trip? Does your map document file store the data? Your friends hear about your road trip plans and decide to join you. They ask for the map document file, so that they can view the route (they took GEOG 281 last semester and already have ArcGIS). If you sent your friends the map document file, could they view the map? Why or Why not? Step 4. Get feedback Whenever possible, ask the person requesting the map for feedback. For now, ask the person sitting next to you for their opinion. 6

7 On Your Own Start a new ArcMap project and save it as Proj2a.mxd. Use the datasets for Texas to create a map that is similar to the one you just completed for the U.S. You must select different symbols and colors. In addition, this map looks better in Portrait orientation. Add labels to the cities, by right clicking on the Texas cities layer and selecting Label features. Don t worry about the placement of the labels for now- later you will learn how to modify the placement of text to make it more effective. Interstate 10 is in Texas? Insert a text field on your map that states: Major Cities along Interstate 10: <List those cities> Your mom hears that you ll be in San Antonio next summer and asks you to visit Aunt Mary in Fort Worth. What road will you take to get from San Antonio to Fort Worth? What city will you pass along the way? Side Trip to Aunt Mary s house Insert a text field on your map that states: Side Trip to Fort Worth: Take Interstate <State the interstate number> through <State city that you will pass through on way to Fort Worth>. When you are finished, save your new map to Proj2a.mxd and export the map as a PDF file. Print a copy of the PDF. Ask the lab assistant to check your Proj2a PDF file. Before you leave, close ArcMap and copy the entire Proj2 folder from C:\Temp to your backup disk. 7