Introduction to GIS: Creating a map from Scratch using ArcMap

ArcMap is a module of ArcGIS that allows you to investigate, manipulate, analyze and create spatial data. ArcMap allows you to create maps using any number of dataset combinations. This is the application you will probably use most frequently to create new datasets, maps, and analysis for your project.

1. The Map Document

In ArcMap, a map document is a file containing a map and display properties. Map documents are constructed using various data but do not contain the actual datasets themselves. A map document is just a text file that contains the path to your GIS dataset.

You create, edit and analyze data in ArcMap, and the map document allows you to save the unique combination of data and symbology that you are working with. When you delete a map document, you are only deleting this combination of data and symbology, not the actual data records.

Opening up ArcMap:

Option 1. Start ArcMap by going to the Start menu > All Programs > ArcGIS > ArcMap 10.5.

Option 2. If continuing from the previous tutorial, click the ArcMap button on the ribbon in the ArcCatalog window to open ArcMap.

At the Getting Started window, select Blank Map and click OK to open an empty map document.

2. Data Frames, Layers and Basemaps

The important features of the ArcMap window are shows in the figure below. The main workspace in ArcMap is known as the Data Frame. Once geographic features are added to the Data Frame, they are displayed as a layer. A layer is a collection of features of the same geometry type. The geometry type used to represent an object depends on the amount of detail that needs to be shown—the same object may be represented as a polygon in one layer and a point in another layer. A city, for instance, could be represented as a point with a unique location in a country or as a polygon with a boundary and an area.

    1. Lets begin by adding basemap to your document, A basemap is the bottom- most layer in the map, and all other datasets are drawn on top of the basemap.

    2. TIP: If you see the globe in the lower right corner of the window spinning, don’t click anything in the program, or the program may freeze completely and crash!

    3. Option 1: Click File > Add Data >Add Basemap. A window opens where you can select the basemap style. Click the cancel button to close the window

    4. Option 2: Click the inverted triangle next to the Add Data button (the plus sign over a diamond), and choose the Add Basemap option.

    1. Examine the options for basemaps. Several styles are probably familiar, such as Streets and Imagery, which are similar to those used in Google Maps. Click the Streets style to select it and click Add.

    2. The Streets basemap will display in the data frame zoomed out to show the full extent of the map. Notice that the TOC now shows a layer called Basemap with a sublayer called World Street Map.

A map document can have multiple data frames, which may be useful for creating maps of different cities or at different scales which you want to display next to one another in the final product. For practice, let’s rename the data frame to something more meaningful than Layers.

    1. Right click on the name of the data frame (Layers) to see the available options. Select Properties.

    2. Select the General tab, if not already selected. Change the Name of the data frame to Dorchester_County. Click OK to accept the changes.

3. Navigating through the Map

There are several tools we can use to navigate around the map document. (Note that they function exactly the same way as in ArcCatalog!) Now you will use them to take a look at the basemap in more detail.

    1. Click the Zoom In button () on the main toolbar. Click anywhere on the map and you will incrementally zoom in toward where you clicked.

    2. Click and drag in the data frame to draw a box. The map document will zoom in to that area.

    3. Click the Zoom Out button (). Click once to incrementally zoom out, then try drawing a box and see the result.

    4. The Pan tool allows you to move around the map without change the scale. Click the Pan button, (), then click on the map and while holding down the mouse button, drag the map to move it.

    5. The mouse wheel can also be used to zoom in and out. Push the mouse wheel away from you to zoom out. Then roll the wheel toward you to zoom in. Notice that the zoom will use your cursor select the area of zoom.

    6. Click the Full Extent () button. This will zoom out to the largest extent of any data in the data frame, so you should see the entire world once again.

Bookmarks save a snapshot of the map location and scale. These are useful if you often zoom or pan in your map but want to return to a particular location frequently.

    1. Using a combination of zoom tools, zoom in to fit South Carolina in the window.

    2. On the Ribbon, click Bookmarks > Create Bookmark. Call it SC.

    3. Click the Full Extent button, then click Bookmarks > SC to go back to the previous view.

4. Adding data to the Map

Now that you are familiar with the parts on ArcMap and how to navigate through it, let's add some data!

    1. First, we will drag data from the ArcCatalog window directly into the map. Position the ArcCatalog and ArcMap windows so they are both visible on the screen.

    2. From the D:\PSA_Training_March2017\Data.gdb database in ArcCatalog, , and click on the Dorchester_Parcels feature and drag it over into the ArcMap frame. The Dorchester_Parcels layer now shows up in the TOC of the Dorcester_County data frame above the Basemap.

    3. Click the ArcCatalog button on the top of the ArcMap window. The ArcCatalog panel opens up on the right side of the window. Click the Pin along the top of the panel to pin the ArcCatalog panel open.

    4. In the ArcCatalog panel, navigate to the D:\PSA_Training_March2017\Data.gdb. Click Waterbody and drag it to the map.

    5. In the ArcCatalog panel, navigate to the D:\PSA_Training_March2017\Data.gdb. Click Road Centerline and drag it to the map.

    6. In the TOC, right-click the Dorcehester_Parcel layer and select Zoom to Layer. This will automatically zoom to the extent of the dataset.

    7. Now create a new bookmark called Dorchester_County.

    8. Click to uncheck Waterbody in the TOC to turn the layer off.

    9. One by one, uncheck all the layers, including the basemap.

    10. One by one, turn the layers back on.

5. Opening up Attribute table

In the Previewing Data tutorial, you looked at the attribute table for a dataset. You can also open the attributes for any layer in ArcMap by right clicking on its name in the Table of Contents ( TOC).

    1. Right-click Dorchester_County in the TOC and select Open Attribute Table. Notice the many fields in this attribute table. You can scroll to the right and/or resize the attribute table window in order to view more fields.

    2. Right click on the GIS_Acreage field and select Sort Ascending. Look at the results.

    3. Close the attribute table.

5. Symbology

Changing the Symbology of polygon feature layer

To begin learning how to change the symbology for the feature class, we start with Dorchester_Parcels.

    1. In the TOC, under the Dorchester_Parcels layer and click on the symbol.

  1. Select Hollow from the options and change the Outline Color to Gray 10%.

    1. Then, In the TOC, under the Waterbody layer and click on the symbol.

  2. Select fill color to blue.

Changing the symbology of a line feature layer

The attributes of a feature can be used to create different symbols within the same layer, and this works for points, lines, and polygons. Let’s make our symbology more complex by using the attributes of our roads to create customized symbols .

    1. In the TOC, open the RoadCenterline attribute table. The Roadclass field differentiates between highways and freeways and using the tools in the Symbology tab of the Layer Properties dialog, we can assign a unique symbol for each category. Let’s try it!

    2. Close the attribute table.

    3. Open the Layer Properties for RoadCenterline (right-click on the layer in the TOC, click Properties).

    4. Navigate to the Symbology tab.

At the left of this window, ArcMap provides us with a few symbology options. In the Show box you have the options to symbolize Features, Categories, Quantities, Charts, and Multiple Attributes. The default (Single Symbol) is currently selected.

4. Click Categories since we are going to use roadclass as the basis for our symbols.

5. Now choose roadclass from the Value Field drop down menu. This is where you set the field containing the attribute you wish to symbolize. Then, click the Add All Values button to list all the available values of the roadclass field.

6. At the top menu click File-> Save -> Myfirstmap.mxd in the D drive under the same folder.

5. Export your first Map

So far, we have only worked in the Data View, which provides a geographic window for exploring, displaying, and querying the data on your map. You work in real-world coordinates and measurements in data view.

In layout view, you work with the map layout elements, such as titles, north arrows, and scale bars, along with the data frame, all of which are arranged on a page. In layout view, you work primarily in page space (typically, inches or centimeters) except when you are interacting with a data frame in your layout.

1. Switch to the Layout View by clicking the button on the bottom of the ArcMap window.

The view changes to show how the current data frame positioned on a Letter size sheet (8.5 x 11 in), the current default. Notice the rulers around the edge of the window and the Layout Toolbar, which are other visual clues that you are setting up a document.

2. Click on your map contents in the middle of the page. Notice that a dashed border and blue squares appear around the edges. You can use these blue squares to resize the map on the page.

9. The next window allows you to set up a border and background to your legend. Because my example map has very dark colors, I will set up a border and background. \Click the dropdown under Border and select 1.0 point, and select White for the background.

10. The next window lets you modify the symbol used in the legend for each of your layers. We will accept the defaults and click Next.

11. The next window lets you modify the spacing between elements in the legend. We will accept the defaults and click Finish to add the legend to the map.

12. Reposition the title, legend, and north arrow to your liking.

13. Click File > Export Map to open the export dialog. Navigate to D:\PSA_Training_March2017 and set the Save as Type to PDF. Name the map (MyName)’s_First_Map.pdf and click Save.

8. In the next window, you can rename your legend and set the font properties, justification, etc. Accept the defaults and click Next.

7. One by one, select each items associated with your basemap and click the arrow to remove it from the list. (Notice the option to select the number of columns in your legend, but keep the default (1)). . Click Next.

6. Click Insert > Legend to open the Legend wizard. The first dialog shows you all the available layers in your map document on the left side, and allows you to choose the items which will display in your legend, which comprise the list under Legend Items. You don’t need the basemap in the legend, for instance, so let’s remove those items.

5. Click Insert > North Arrow. Scroll through the options and select one to your liking. Click OK to add it to the map.

3. Hover your mouse over a blue square and notice the cursor changes to a dual-headed arrow. Click on the blue square in a corner of your map and drag it to resize the map frame.

Click on Insert > Title to add a title text box to the map. Double click in the text box and rename your map something like (My name)’’s First GIS Map. Click the Change Symbol button and change the font size to 36. Click OK and OK to close the title properties.