Geography 281 Mapmaking with GIS Project One: Exploring the ArcMap Environment

Transcription

1 Geography 281 Mapmaking with GIS Project One: Exploring the ArcMap Environment This activity is designed to introduce you to the Geography Lab and to the ArcMap software within the lab environment. Before you begin to explore the Geography Lab and ArcMap software, let s review some basic information on file management. File Management The computer stores files, e.g., Word documents, database files, pictures, and map documents, in a directory tree structure on the computer s hard drive and on network drives connected to the computer. This structure is similar to a file cabinet with many drawers, each drawer containing several folders, and each folder containing one or more files. Below in the MyComputer example, imagine a file cabinet labeled C:\ with a drawer labeled Temp. If you open the Temp drawer you would find a folder named Proj1 and inside that folder another folder called MapDocuments with a file called proj1.mxd inside it. Computers use a similar process called a path to find where files are stored on the computer s drive. Each path contains the filename and the directories in which it is located. For example, the path for proj1.mxd is C:\Temp\Proj1\MapDocuments\proj1.mxd (visually you can see this in the Sample Directory Tree Structure diagram). This is the exact path the computer takes in locating this file. Project Organization While you could store all your files jumbled together in the file cabinet, it makes more sense to organize them by project. A standard directory structure would look like this: Project folder containing all project related material: o Data folder containing all project data o Documentation folder containing all project documentation o Map Document folder containing all project map documents (.mxd) Clearing Out the Temporary Working Directory All your work will be done in the working directory C:\temp. Before setting up your files, you should clear any existing files left behind by someone else. The desktop includes an icon linked to a program that will clear out the C:\temp directory: Double-click on the Deltemp icon If prompted, enter the letter "y" Page 1

2 Copying Project Files to Your Working Directory Before you begin a project, you must copy the project files from the server to your local computer. Server information- Most of the data used in Geography 281 is stored on the Geography Lab server named Geogsrv, in the shared drive called data. When you log in to the lab machine, you gain access to the network and this server. Using the MyComputer concept discussed above, Geogsrv can be thought of as another file cabinet, with a drawer labeled data. This resource is a network drive and is assigned a letter; usually this directory appears as drive Z:\ on the lab machines. You should always have access to the data on Geogsrv directory. Under the Geogsrv\data directory is a subdirectory called Geog281, this is where you will find the project directories (Proj1, Proj2, etc ) containing weekly project data. You will use the ArcGIS Desktop application called ArcCatalog to copy data from the server to your working directory. ArcCatalog was designed to move geographic data (like that stored in shapefiles and geodatabases). See graphic example below. ArcCatalog on the right knows that a shapefile is a collection of files stored on the computer with the same name and different extensions. In ArcCatalog you see a shapefile as 1 file, while all the supporting files with various extensions are hidden. This makes moving shapefiles easy you click on the shapefile you wish to move and ArcCatalog ensures that the supporting files are automatically moved as well. Proj1 data as viewed in Windows Explorer ArcCatalog Understanding how geographic data is stored- In ArcMap you make maps from layers of spatial data. A layer doesn t store the actual spatial data, it references the data stored in shapefiles, coverages, geodatabases, etc. In Geography 281, we will be working with shapefiles and geodatabases. This week you will use shapefiles to create your map. A shapefile is a collection of files with the same filename and different extensions. For example, Project 1 uses 2 shapefiles- us48_states and counties48. These are located in the Proj1\Data directory. Shapefile: us48_states counties48 Files on disk us48_states.shp counties48.shp associated with us48_states.dbf counties48.dbf each shapefile: us48_states.prj counties48.prj us48_states.sbn counties48.sbn us48_states.sbx counties48.sbx us48_states.shx counties48.shx A geodatabase is a common data storage format. Instead of storing data as separate files within the data directory, these files are centrally stored in a database designed to hold spatial data. We will use a geodatabase next week. Using ArcCatalog to copy project data from server: Start ArcCatalog- Start All Programs ArcGIS ArcCatalog In the ArcCatalog Catalog Tree navigate to the <mapped drive>:\geog281 directory, where <mapped drive> refers to the letter assigned to the Data on Geogsrv network connection. Z is the letter most lab computers use to note this connection. Page 2

3 If <mapped drive>:\geog281 is not visible, you will need to add a folder connection: o Click the Connect to Folder Button. o Navigate to data on \\Geogsrv. You can find this directory by looking under Computer. o Under the data folder, you will find a subdirectory called Geog281. Connect to this folder. o Click OK. The new folder connection now appears under Folder Connections -- <mapped drive>:\geog281. Double click on the new folder. Right click on the Proj1 directory and select Copy. Navigate to C:\temp. If C:\temp is not visible, you will need to add a folder connection. Follow the steps above to connect to the C:\temp folder. Press the X in the upper right to close ArcCatalog. The proj1 directory under data on Geogsrv should now be copied to the C:\temp directory on your local computer. You are now ready to start using ArcMap. Starting ArcMap and Loading a Map Document File In the first exercise, you will load a preexisting map document. ArcMap stores the map with both the layout and reference to the geographic data as one file called a map document. This file has an.mxd extension. This file does NOT contain geographic data, it merely references the path to data. Left-click the Start button. From the Start menu, select All Programs ArcGIS ArcMap From the ArcMap File menu, select Open. Navigate to C:\temp\proj1\MapDocuments directory, click on Proj1.mxd and select Open. Views, Tables and Layouts At the heart of the ArcMap program are two versions of the same map: The Data View displays geographic information in the form of a map. This is where you can symbolize, analyze, and compile various geographic layers. The Layout View displays the map itself plus additional cartographic elements (title, legend, scale bar, etc.). To toggle between the two displays select View Layout View or View Data View from the Main menu. When working on the geographic data that make your map, it is usually best to stay in the Data View mode. When working on an overall cartographic composition, you should be in the Layout View mode. Working with the Data View Below is an image of the Data view with various components identified. When you add data to your map, it appears as a Layer in the Table of Contents frame. This project contains two geographic layers: Main Menu Table of Contents The layer named States has been modified so that only the state boundaries are visible. This layer points to the us48_states shapefile located in your C:\temp\Proj1\Data directory. A second layer named Persons per Sq. Mile consists of population density information for the individual counties that make up the U.S. This layer points to the counties48 shapefile located in the same directory. Standard Toolbar Tools Toolbar Map Document Window- Data View Overlaying one layer of information on top of another and assigning different symbols and colors to different categories of information are examples of the kinds of operations that you would perform in the Data View. Other Data View operations include zooming in on small geographic areas and querying the database to retrieve information about individual geographic features. For example, you can zoom in on Southern California and click on the map to retrieve information about the region's population density. Page 3

4 On the Tools toolbar, click once on the Zoom In button to select it. This tells ArcMap that you want to use the mouse to zoom in on a portion of the map. Move the cursor to an area of the Pacific Ocean northwest of Southern California. Drag the mouse while holding down the left mouse button to a point southeast of Southern California. When you release the mouse button, the map will zoom in on the area you defined as your zoom box. Working with the Attribute Data Table Each feature layer includes an attribute table that lets you see information about individual features items on the map) in a tabular (row and column) format. Each row represents an individual geographic feature (i.e., a state); each column represents a particular type of information about those features (i.e., state name). Let's highlight California in the table: Move the mouse over the States layer name in the Table of Contents and click the Right mouse button. Select Open Attribute Table. You should see the following table appear. ArcMap lets you point to a geographic feature on the map and obtain information about it from the database. Click once on the Identify button, also found on the Tools toolbar. In the Identify Results dialog box press the down arrow next to the Identify from: field and select Persons per Sq. Mile as the layer about which you want information. With the Identify Results window still visible, click Orange County, California in the map. You should see information about the county such as the county name, population density, etc., appear in the Identify Results window. Finally, restore the full map view: Close the Identify Results dialog box by clicking on the X in the upper right hand corner. Click once on the Full Extent button in the Tools toolbar to restore the full map view. You now have been introduced to three different kinds of tools: Buttons such as Full Extent that produce an immediate change in the map view. Tools such as Identify that require a mouse click on the map before they cause something to happen. Menu items such as the View menu with all its options that may either produce an immediate action or set the conditions for a subsequent action. In the Attribute Table window, find the field named STATE_NAME. Scroll down until you see the name California in the STATE_NAME field. Each geographic feature and its associated information in the table are directly linked to the same feature on the map. Move the mouse to the far left of the row containing California information and click on the gray square to the left of the FID field. The row is now highlighted with a light blue color to show that it is selected. Close the table window and check to see that the outline of California is also highlighted in the same light blue color. When a feature is selected, ArcMap lets you make choices that only apply to the selected feature. For example, you can zoom in on the selected feature: On the Main menu, select the Selection menu, select Zoom to Selected Features. Page 4

5 Because the data displayed in the table is the same data displayed in the map, the View window knows that "California" is selected. The map zooms in to show the entire state of California. Now it's time to work with the Layout View. From the Main menu, select the Selection menu, choose Clear Selected Features. On the Tools toolbar, click on the Full Extent button. Finally, switch from the Data View to the Layout View: From the Main menu, select the View menu, choose Layout View. Working with the Layout View The Layout View is where you prepare your map for final viewing. The Data View provides you with a view of geographic data used to create your map; whereas the Layout View is similar to a sheet of paper on which you arrange the various components of your map (title, legend, map itself, etc.). In the Layout View you create, move and resize a collection of rectangular frames - each of which holds an individual cartographic element. The Project 1 map document file contains a preset Layout View that illustrates these mapping elements. The image below shows the preset Layout view for Project 1. Most of the ArcMap tools that work that work in the Data View also work in the Layout View. (ArcMap also provides additional Layout tools that only work with the Layout View). The Select Elements tool found in the Tools toolbar is one that works in both views: Click once on the Select Elements button. Click once on the Legend in the lower left of the map. Note the blue boxes that define the four corners of the legend box. These tell you that the legend frame is selected and available for editing. Position the mouse over the legend box note the change in the shape of the cursor. Press and hold the left mouse button. Drag the mouse toward the left or right and note how the legend frame moves. Click outside the map page to remove the selection from the legend frame. Note how the legend is now repositioned. Click again to reselect the legend frame. Move the mouse over one of the corner (blue boxes). When the cursor changes shape, press and drag to resize the frame. Note how the size of the legend has changed. You can now begin to understand how you create and edit map compositions in the Layout View. Title Map Document Window- Layout View Finally, click once on the title to select it. Position the mouse inside the title frame. Press the right mouse button and chose Properties from the popup menu. Change the title text to: United States Population Density. Press OK. Legend Scale Right clicking on an element to view and change its properties is one of the most common methods you will use in ArcMap when you want to make changes to a map. Page 5

6 On Your Own Have this map checked in order to get credit for the lab. Use the Main menu s View menu to restore the Data View for your map. Remove the check next to the Persons per Sq. Mile layer so that only the outline of the 48 states is visible. Right click on the name States in the Layers list and choose Properties. Click on the Symbology tab. Click on the Symbol (gray rectangle). The Symbol Selector dialog box appears. Select a new color (for example, Yellow), and click OK twice to close the Properties window. Note: If your map no longer contains individual states, it is because the fill pattern you selected does not have an outline width or color. Modify the symbology of the states to include an outline. Explore your data. Open the Attribute Table for the States layer. o Which state has the highest population density (POP00_SQMI)? o Which state has the lowest median age (MED_AG)? Return to the Layout View and change the title to something more appropriate such as Outline Map of the United States. From the Insert menu, select Text o In the textbox that appears, write the following using the information gathered above to fill in the blanks: Fun Facts: has a population density of has a median age of Note: you have saved the project settings in a file named proj1.mxd located in the C:\temp\Proj1\MapDocuments directory of the computer. You still need to copy the files to your portable drive for permanent backup. To copy your project to your backup disk, you ll need a Flash drive. If you don t have one yet, skip this part for now. Copying Files to Your Disk Using ArcCatalog Place the Flash drive in a USB port. Start ArcCatalog - Start All Programs ArcGIS ArcCatalog o Navigate to the C:\temp directory on your local computer. Right click on the Proj1 directory and select Copy. Navigate to < Removable Disk mapped drive>:\. If the removable disk is not visible, you will need to add a folder connection. Right click on the new folder and select Paste. When the Proj1 directory has been written to your disk, close ArcCatalog and remove your drive. Copying Files from Your Disk Using ArcCatalog Sometimes, you will need to continue working on a project that you saved to your portable disk. This section details how you would copy and paste projects from your disk to your local computer. Do not work directly from your portable disk, you may lose your work. Start ArcCatalog- Start All Programs ArcGIS ArcCatalog Navigate to < Removable Disk mapped drive>:\. Right click on the Proj1 directory on your removable disk and select Copy. Navigate to C:\temp. Right click Paste. Saving Your Work and Exiting ArcMap When you are ready to save your work: From the Main menu, select File Save. From the Main menu, select File Exit. Page 6