2010 GIS Summer Workshop Skills

Table of Contents
Copy Data Files to the Desktop
Create a Personal Geodatabase
Add a Base Map to Your Map Document
Table of Contents: Display and Source Tabs
Joining Tables
Using Selections to Analyze Data
Create an Attribute Selection Using a Formula
Save your Selection as a new Layer
Create a Selection Based on Location
Change the Symbology
Design a Map Layout



Krista White
GIS Support Specialist
x 3926
Kwhite2@drew.edu
Office HS 337
T, Th 8:00AM-12:00PM, 1:00PM-4:00PM
F 8:00-11:30AM

Catherine A. Riihimaki
Assistant Professor
Environmental Studies and Sustainability
x 3349
criihimaki@drew.edu
Office HS 100

Copy Data Files to the Desktop

To complete this tutorial, you will need to copy the Geocoding folder from the O:\envstudies\2010 GIS Summer Workshops folder to the desktop of your computer. If you have done this already, skip to the next section, Start a New Map Document.

  1. Go to the Start menu


  1. Click My Computer

  1. Double click on the O: Drive





  1. Folders are listed alphabetically by department acronym. Double click on the envstudies folder.



  1. Double-click on the 2010 GIS Summer Workshops folder. Inside you should see another folder for your project.


  1. Right click on the folder for Your Project, and choose the Copy option.


  1. Close the GIS Tutorial window.


  1. Right click anywhere in the blank, blue space on the Desktop. Choose the Paste option. You should now see the Project folder on your Desktop.


Create a Personal Geodatabase

A Personal Geodatabase is a tool that keeps all of your data for a map document in one convenient location. Creating a Geodatabase helps users to organize and conceptualize the data they have. This makes it easier to work with the data later. Some tools created for ArcGIS require the use of a Geodatabase to function properly.

  1. Open ArcCatalog


  1. In the Table of Contents column on the left hand side of the screen, navigate to your Desktop by using the Connect to Folder button.



The Desktop will be listed in the Table of Contents as I:\yourusername\Desktop.

  1. Choose the Project folder you imported from the Environmental Studies drive.


  1. Double-click on the project folder in the Table of Contents; the folder icon will change to an open folder icon, and the items in the folder will be listed in the main display area.


  1. Right click on the Cartograms folder. Choose New → Personal Geodatabase. A Personal Geodatabase icon will appear in the main display area.



To rename the database, click twice slowly on the name. When the name of the Geodatabase is highlighted in blue with a thick, black line around it, type in the new name – whatever you want to call your new map document.

  1. Close ArcCatalog.



Add a Base Map to Your Map Document

Base maps are the foundation of all ArcGIS map documents. In the Geocoding tutorial, you learned to add base map from the ArcGIS server. Hawth's Tools has some very specific requirements for map creation that are not met by the ArcGIS server maps. Other kinds of base maps are freely available from many sources. You can find many of these resources at the Drew University Environmental Studies and Sustainability GIS Resources web page.

  1. Click the Add Data button.


  1. In the Look In: menu of the Add Data dialog box, highlight the files you want to add to your map. There are usually a set of shape files to use as base maps that you add to every map document. If you have extra data in a .dfb or .csv file, you will add that the same way to the map document. If you want to import Excel files into ArcGIS, you must save them as .csv files first.

  1. Click the Add button.



The Data Frame should now contain a map (if you added a shape file).



The Display tab in the Table of Contents – located on the left hand side of the screen – should now display the name of the maps shape file you just added.


Table of Contents: Display and Source Tabs

Data files like .dbf and .csv files will not show up in the Table of Contents when you are viewing it with the Display tab. Display is the default mode for viewing files in the Table of Contents. To view all files you've imported to the map document, click on the Source tab at the bottom of the Table of Contents.

Different types of files can be identified in the Source tab by the icons that represent them.

The icon that looks like a file folder with an overlaid map is indicates the file path for the entire map document. This lets you know where all the files for this map document are stored.
An icon that looks like a spreadsheet table indicates a data file of some type. Usually a .dbdf or .csv file.

An icon that looks like a cylinder indicates a Geodatabase. Any elements appearing indented and underneath the Geodatabase icon are files stored in that Geodatabase.


Joining Tables

Any time you want to add external data (.dbf or .csv file) to a map file, you need to join the data from the external file to the data table contained in the map. To Join one or more tables, there has to be a common field among them. In many cases, a geographic identifier – like a Census designation for a Block or region – is the common field. Common fields can be any element – so long as they match the data from one file to another correctly.

  1. Add the files you want to join to your map document.


  1. Right click on the layer that you want to join data TO. This is often the map shape file. Choose Joins and Relates → Join…. The Join Data dialog box will appear.


  1. Select the following settings: Join attributes from a table

Choose the field in this layer that the join will be based on: This will be the field in the first file that has identical values to a field in the second file.
Choose the table to join to this layer: This is the second file.
Choose the filed in the table to base the join on
This is the field in the second file that has identical values to a field in the first file.
This common element of identical values in the fields of each file provides the reference point to add the data from one table to another.
Join Options: Keep all records

  1. Click OK


Using Selections to Analyze Data

ArcGIS allows users to display information on maps by selecting certain sets and subsets of data available in the map. This can be useful for eliminating data or highlighting data specific to user needs for a particular function.

  1. Go to the Selection pull down menu. Selections can be made by Location or by Attribute.
    1. Location selections are useful if you want to narrow data by an area defined in the map.
    2. Attribute selections are most commonly used. Attributes are the fields in the data tables that underlie the map.


This example will use Attribute Selection. I want to select the addresses of commuter students I've mapped that are no farther than 10 miles away from Drew.

Create an Attribute Selection Using a Formula

  1. Choose Select by Attributes. A dialog box will appear.
    1. Under Layer: choose the layer from which you want to select the attributes



















    1. Under Method: choose Create a new selection
    2. In the box below Method, there is a list of the elements from the Attributes Table of the Commuter Locations layer. I know that the "ComDist" Attribute is the one that contains the distance calculation from Drew for each student address.


  1. Under SELECT " FROM Commuter Locations WHERE, there is a free text box. This is where you can write formulae to narrow Selection criteria.


I want only distances of 10 miles or less in my Selection, so I create a formula:

    1. Double-click on "ComDist" in the box above.
    2. Double-click on the < = button.
    3. Type a space and then key in the number 10. Make sure that there is only once space between the < = symbol and the number 10.
  2. Click OK. Now all of the elements in our Selection – addresses 10 miles or fewer from Drew – are highlighted in the map in cyan.
















Save your Selection as a new Layer

If you save your Selection as a new layer, you will be able to work with and Symbolize the selected elements of the map without changing the original base data you took the Selection from.

  1. In the Table of Contents of your map, right click on the layer from which you created the selection.


  1. Choose Selection → Create Layer From Selected Features. The new layer will show up automatically at the top of the Table of Contents. The name convention will be nameofoldlayer selections. ArcMap will automatically make the data points in the new layer a different color.


  1. Rename the new layer based on selections.


  1. Remove the cyan highlights by clicking on the Selections pull down menu and choosing Clear Selected Features.


Create a Selection Based on Location

One of the most frequent uses for location based Selections comes from creating buffers and then analyzing data points that intersect with those buffers.

Create a Buffer

Buffers are a tool used to indicate an area of proximity for one or more data points. Instead of locating addresses within 10 miles of Drew using an Attribute Selection, we can also do it with a buffer.

  1. Click on the ArcToolbox icon


  1. Open the Analysis Tools in ArcToolbox. Expand the Proximity toolset. Choose Buffer.

  1. Fill in the boxes with the desired values.


    1. Input Features indicate the layer that has the location where you want to have the buffer indicated
    2. Output Feature Class is the location on your computer and the file name for the buffer result you will generate.
    3. Linear unit is the unit of measurement you want to use.
    4. The Dissolve Type determines which features in a buffered data point are retained.
      1. ALL – Eliminates any individual features of that data point except the shape information – no other data is preserved
      2. NONE – Retains all data fields about a value and adds shape information from the buffer function.
      3. LIST – only applies if you specify a Field rather than a Linear unit on which to base your buffer. Groups the input features based on the field you specify.

When in doubt, set your Dissolve Type to ALL.
When your Buffer is done rendering, it will appear in the Table of Contents with the name you specified in the Ouput Feature Class field. Your feature(s) will be surrounded by a halo representing the linear unit or field you specified.



Intersect Features with Buffer

You can now do an intersect analysis to Select any features that intersect with the buffer created.

  1. Go to the Selection pull down menu. Choose Select by Location.


  1. Fill in the data fields as follows:


    1. I want to:
      1. Select features from the following layer:

Choose a layer that you want to select data points from.

    1. that:
      1. intersect


    1. the features in this layer:

Choose the layer of your Buffer
Your Selected features will appear highlighted in cyan.

  1. Right click on the layer from which the selected features were chosen (from the "I want to" – section 2a. – above). Save the Selected Features as a Layer File.


Change the Symbology

Symbology indicates what kind of icon and color represent your data points or other features on the map. Size, color, and type of symbol can be crucial in creating an easy to read map. To change symbols for your map,

  1. In the Table of Contents, right-click layer you want to adjust and choose Properties… from the pull-down menu.


  1. Choose the Symbology tab and click the square showing the current symbol under the heading "Symbol."



  1. Change the symbol to the desired shape, color, and size.


  1. Click OK twice to see the new Symbology.



Design a Map Layout

  1. Choose Layout View from the View menu to see how your map would look on a printed or exported page.


  1. The Layout Toolbar should now be active. You can use this toolbar to navigate the layout page, while the Tools Toolbar can still be used to navigate the map itself.


  1. From the Insert menu, add a title and legend to your map.


  1. To modify any new layout item (e.g., the legend), right-click the item and choose Properties from the pull-down menu.


  1. When you are happy with your layout design, choose Export Map… from the File menu. You have a variety of image formats that can be used, and the option to change the resolution to meet your needs. Save the map as MyMap.pdf with format type PDF and resolution of 300 dpi.
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