Editing & Creating Your Own Shapefiles in ArcMap 10

J. Baldridge, February 2012

ArcMap allows you to create and edit your own shapfile layers. There is a new method of doing this in Version 10 of the software. Here is an example of how to do this.

PART 1: START WITH A BASE MAP

1) Go to census.gov and click “Geography”
2) Then, click “TIGER Page”>>”TIGER/Line Shapefiles & Files”>>” 2010 TIGER/Line® Shapefiles Main Page” (Note that the 2011 TIGER page is still incomplete).
3) Click “Download Shapefiles”
4) From the dropdown list, choose “Counties (and equivalent)” and click “Submit”
5) From the “County and Equivalent (2010)” dropdown list, choose “All states in one national file” and click “Download.” This will download a boundary file of the entire US, divided up by county boundaries. Open it in ArcMap 10 and check it out.

PART 2: EDIT YOUR BASE MAP AS NEEDED

For this example, we want to focus on Alaska, so we won’t need the rest of the US.

1) Use your editing tools to delete everything but Alaska.
2) “Stop Editing” and Save your Edits
3) Zoom to “Full Extent”
4) This view of Alaska looks quite distorted. Let’s apply a projection to help make it look a bit more accurate.
5) Open the Properties of the Data Frame called “Layers” and click on the “Coordinate System” tab
6) Browse the folders to find a “Predefined”, “Projected Coordinate System”
7) Choose “UTM” and then “NAD 1983”
8) Select “NAD 1983 UTM Zone 5N”
9) Click the “Full Extent” button.
10) Save your map as “Alaska UTM Zone 5”
11) Adjust color to your liking


PART 3: CREATE A NEW POLYGON LAYER

Let’s say you want to propose a new wildlife refuge area in Alaska. You will need to create a new layer that shows the boundaries of the refuge. Let’s practice drawing the boundaries of your proposed refuge.

1) Open ArcCatalog
2) Right-click on the folder you are working in
3) Choose “New>>Shapefile”
4) You will see a new window on the screen called “Create New Shapefile”
5) Give your new shapefile a “Name” (like “Refuge)
6) Under the “Feature Type” dropdown, choose “Polygon.”
7) Note: if you wanted your new layer to be a points layer, you should choose “Points” etc.
8) Under “Spatial Reference: Description” you will see “Unknown Coordinate System”; but you want your new shapefile to line up with the coordinate system of your base map of Alaska.
9) To ensure this, click the “Edit” button.
10) To save time, click “Import” button
11) Select and “Add” the shapefile that is your base map, and then click “OK.” This assigns the same GCS to your new layer as that of the base map.
12) Note that the “Create New Shapefile” window now displays “GCS_North_American_1983” as the “Geographic Coordinate System.” This is the same GCS as the file you originally downloaded from the Census. So far, so good.
13) When you click “OK,” a new layer will appear in the Table of Contents on the left hand side of the screen. If you followed the directions above, this new layer will be named “Refuge.”
14) Save your map.

PART 4: EDIT THE NEW LAYER TO INCLUDE YOUR OWN DATA/DRAWINGS

You have created a new Polygon layer called “Refuge.” However, this layer has no data or drawings in it! The next step is to Edit this layer to add your own polygons, using the ArcMap 10 Drawing Tools.

1) Right-click the layer called “Refuge” and select “Edit Features>> Organize Feature Templates”
2) In the window that opens, select “Refuge” and click “New Template”
3) The “Create New Templates Wizard” will appear.
4) Make sure “Refuge” is checked and click “Finish”
5) Close the “Organize Feature Templates” window
6) Right-click the “Refuge” layer and select “Edit Features>>Start Editing”
7) If any warnings appear, click “Continue” (and cross your fingers)
8) A new “Create Features” pane will appear on the right-hand side of the screen. “Refuge” should appear as one of the layers in this pane.
9) Click on “Refuge” in the right-hand pane. Note that, in the bottom-right area, you can see some “Construction Tools” and that “Polygon” is selected.
10) If you move the mouse into the central map area, the cursor is now a crosshair (like a plus-sign)
11) Experiment with clicking and drawing the outlines of polygons on top of your base map layer of Alaska.
12) The general rules are: each click creates a new vertex of the polygon, and double-clicking finishes drawing the new polygon.
13) If you don’t like the polygon you just drew, you can delete it by pressing the Delete key, just after double-clicking to finish drawing it.
14) Draw a polygon for your new Refuge.
15) When you are satisfied, click “Editor” in the editor toolbar, select “Stop Editing” and save your edits.
16) You have created a new polygon in the Refuge layer! Congratulations!

PART 5: CREATE A “POINTS” LAYER AND ADD THE LOCATION OF THE REFUGE HEADQUARTERS

Imagine that you want to add the location of a Refuge HQ to the map. You will need to follow the same steps you followed in Part 3 and Part 4, but with the following differences:

1) When you create the new shapefile in ArcCatalog, choose “Point” instead of “Polygon”
2) Give the new shapefile a different name, like “HQ”
3) Your “Construction Tools” for the Point layer will be different from the Polygon layer’s construction tools. Experiment with them.

PART 6: EDIT THE ATTRIBUTE TABLES OF YOUR NEW LAYERS

Your new layers have attribute tables, but they are empty of useful data. Let’s say you want to enter a name for the Refuge layer and a name for the HQ. Also, let’s suppose you want to enter the number of acres the Refuge covers.

1) Make sure you have stopped Editing (i.e. are not in Edit Mode)
2) Open the Attribute Table window for the “Refuge” layer
3) Click the button in the upper-lefthand corner of the window (“Table Options”)
4) Click on “Add Field”
5) In the “Add Field” window that appears, type a name for the new field: NAME
6) Because the name of the Refuge is a string of text, choose “Text” from the “Type” dropdown list
7) Note that the Field Properties information indicates that your text cannot be more than 50 characters. You can change this if you need more characters by clicking on and changing the number of characters.
8) Click OK, and watch the new Attribute Table field appear
9) Start Editing (ignore any warnings)
10) Click on the cell under the NAME field heading in the first row
11) Type the name you want to appear in the Label for your refuge
12) Stop Editing and save your edits
13) Close the Attribute Table and turn on Labeling for the “Refuge” layer. You should see your text appear on the map. If you don’t, go to the “Labels” property of the “Refuge” layer and make sure that “NAME” is selected for the Label Field.
14) Repeat this process with the “HQ” layer to give the headquarters a name in the “HQ” attribute table

To add a field that contains the number of acres in the refuge, follow the same steps, but with these changes:

a) in Step 6, choose “Double” instead of “Text” because acreage is a number, not a text string. You could also use “Long Integer,” but “Double” allows you to use decimal fractions instead of just integer numbers.
b) Otherwise, the process is the same

Later, if you wanted to add new data to your layers, you could either create new fields in the ArcMap Attribute Table, or create an Excel file that you could Join to your new layer.