533565235
Page 1 of 14
Intermediate GIS Skills Using ESRI’s ArcGIS Software
Objectives
In this exercise you are introduced to the ArcMap interface and some of the basic skills necessary to begin
exploring geospatial data and create simple maps. Once you have successfully completed this part of the
tutorial, you should know:






How to use the Union Tool to combine to
feature data sets
How to create new fields in a feature
dataset or table
How to calculate the geometric attributes of
a feature
How to calculate attribute values across
feature attribute fields
How to Join datasets based on attribute
values
How to Join datasets based upon location






How to create Summary Statistics tables
from datasets
How to Geocode tables of street addresses
How to create a distance raster to measure
distance for a feature dataset
How to extract raster values to a point
feature dataset
How to aggregate point features to counts
in a polygon dataset
How to set Relative Pathnames to make
your GIS Projects more portable
Download the Data
The datasets used in this tutorial are available for download on the Map Collection Website. Feel free to
download and use these tutorial materials, as you wish, and to pass them along to interested colleagues.
Go To the Map Collection Homepage (www.library.yale.edu/maps) in your Web Browser.
Under the Quick Links Section on the right, Click on the “Download GIS Workshop Materials” link.
Find the “Data” Link for the ArcGIS 9.3.1 “Intermediate GIS Skills Using ESRI’s ArcGIS Software” and
Right-Click on the Link.
In Firefox, Select “Save Link As,” in Internet Explorer, Select “Save Target As…”
Depending on your browser and setup, you may be offered a Browse Window, to select the folder into
which you want the downloaded file placed. If so, Browse to a Folder on your hard drive that you have
write permission for. For this tutorial, we will assume that you are using the C:\temp folder of the machine
you are working on.
Save the Downloaded File to the C:\Temp Folder.
Unzip the Data
You should now have a file called “Intermediate_GIS_Skills.zip” in your new folder. It is now necessary to
decompress, or unzip, the tutorial data for use. Note that in Microsoft Windows XP and Vista, it is possible
to “Explore” a compressed file, as if it were a folder. ArcMap does not support this type of browsing, so it is
necessary to actually unzip the file for use. This part of the tutorial assumes that you are using Windows’
built in Compressed File support.
The Yale Map Collection
At Sterling Memorial Library
130 Wall Street, Room 707
Stacey Maples – GIS Assistant
203-432-8269 / stacey.maples@yale.edu
www.library.yale.edu/maps
533565235
Page 2 of 14
1. Browse into the Folder where you saved the
Intermediate_GIS_Skills.zip file.
2. Right-Click on the File and Select “Extract All…”
3. Click Next to arrive at the window shown at the right.
4. Click Next to Extract the File.
5. When finished, browse to the
C:\temp\Intermediate_GIS_Skills\ and double-click
on the Intermediate_GIS_Skills.mxd Map Document
file to open it.
Analysis with ArcGIS
In this tutorial, we will be performing what is referred to as “Areal Interpolation” of Census Attributes. We
have a set of boundaries (in this case the Major Watershed Basins of Connecticut, our CT_Major_Basins
Layer) for which we would like to summarize the population. Our
problem is that these watershed boundaries do not correspond with
the geographic units that the U.S. Census uses to collect and tabulate
demographic data. Some of the Census Block Groups in our
CT_Block_Groups layer overlaps more than one Watershed basin
unit. What we will do in the following steps is calculate the proportion
of overlap for each Census Block Group, relative to the Watershed
Boundaries, and use these proportions to assign an appropriate
estimate of the population to each watershed.
Calculating Geometry for a Data
Layer
First, we need to determine the initial
area of each of our “intact” Census
Block Groups. We can refer to these
as the “Parent” features.
1. Right-Click on the
CT_Block_Group Layer and
Open the Attribute Table.
2. Take a few seconds to examine
the data available in this
dataset. This data describes the
demographic characteristics of
The Yale Map Collection
At Sterling Memorial Library
130 Wall Street, Room 707
Stacey Maples – GIS Assistant
203-432-8269 / stacey.maples@yale.edu
www.library.yale.edu/maps
533565235
Page 3 of 14
every Census Block Group in our area of interest.
3. Click the Options Button at the Bottom of the Attribute Table and Select Add Field...
4. Add a Field with Name = AREA, and Type = Float.
5. Click OK.
6. Scroll to the far right of the Attribute Table to
view the newly added AREA Field.
7. Right-Click on the Area Field Header and Select
Calculate Geometry… Click Yes when warned
about “Calculating Outside and Edit Session.”
8. Change the Units to Square Miles US [sq mi].
9. Click OK.
10. Note that the AREA Field should now be
populated with the new values.
11. Close the Attribute Table
Geoprocessing: Using the Union Tool
Now, we need to merge the Block Group and Watershed boundary files, so that those Block Groups that
span more than one watershed will be split into their sub-units of overlap, or “child” features. To do this, we
will use a technique generically referred to as “Geoprocessing.” Geoprocessing is the act of applying any
number of spatially transforming tools to a dataset. In this case, we will use
the Union Tool to create a new dataset.
12. Open the ArcToolbox using the ArcToolbox Button
Standard Toolbar.
on the
13. Click on the Search Tab, at the bottom of the ArcToolbox Panel.
14. Enter “union” as your search term and click Search.
15. Double-Click on the Union Tool, from the Analysis Tools Toolbox.
16. Select the CT_Major_Basins and CT_Block_Groups Layers as the
Input Features.
The Yale Map Collection
At Sterling Memorial Library
130 Wall Street, Room 707
Stacey Maples – GIS Assistant
203-432-8269 / stacey.maples@yale.edu
www.library.yale.edu/maps
533565235
Page 4 of 14
17. Click on the Show Help>> Button at the bottom of the Dialog Box and note that the Help System is
Context-Sensitive.
18. Save the Output Feature Class
to your
C:\temp\Intermediate_GIS_Skil
ls\CT_Watershed_Data.gdb
and name it “Union”
19. Leave the remaining options at
their default settings.
20. Click OK to Apply the Union
Tool.
21. Click Close once the process
has completed.
22. You should be left with a new
Union Layer, at the top of your
Table of Contents.
Calculating the New Area of the Union Results
Now we need to calculate the NEW AREA of those “Child” Block
Groups that were split by the Union Process and then the proportion
of their original AREA.
23. Right-Click on the Union Layer and Open the
Attribute Table.
24. Click on the Options Button and Select Add Field…
25. Add a new field: Name = SUBAREA, Type = Float.
Click OK.
26. Click on the Options Button and Select Add Field…
27. Add a new field: Name = WEIGHT, Type = Float.
Click OK.
28. Click on the Options Button and Select Add Field…
29. Add a new field: Name = WTPOP, Type = Short
Integer. Click OK.
30. Scroll to the right of the Attribute Table to find the
newly added SUBAREA Field.
The Yale Map Collection
At Sterling Memorial Library
130 Wall Street, Room 707
Stacey Maples – GIS Assistant
203-432-8269 / stacey.maples@yale.edu
www.library.yale.edu/maps
533565235
Page 5 of 14
31. Right-Click on the SUBAREA field header and Select Calculate Geometry…
32. Change the Units to Square Miles US [sq mi].
33. Click OK to apply the calculation.
Now we will calculate the proportion of the child area to parent area, which will be used as a weight to apply
to the demographics we are interested in. First, we must exclude those polygons that have an AREA=’0’
(these are coastal “slivers” and are not important to the results of our analysis).
34. Click on the Options Button and Select “Select by Attributes…”
35. In the Query Argument panel, at the bottom of
the Select by Attributes Dialog Box, enter the
query:
"AREA" <>0
36.
37. This will select only those records that do not
have an AREA = 0.
38. Click on the Verify Button to check your SQL
Query Syntax.
39. Click Apply.
40. Click Close.
41. Right-Click on the WEIGHT field header and
Select Field Calculator…
42. Use the Field Calculator to build the following
argument:
[SUBAREA] / [AREA]
43. Click OK to apply the calculation and note that,
because you have an active select, the calculation is
only applied to the selected subset of records, thus
avoiding a “divide by 0 error.”
44. Finally, Scroll to the far right of the Attribute Table,
Right-Click on the WTPOP field header and select
Field Calculator…
45. Use the Field Calculator to build the following argument:
The Yale Map Collection
At Sterling Memorial Library
130 Wall Street, Room 707
Stacey Maples – GIS Assistant
203-432-8269 / stacey.maples@yale.edu
www.library.yale.edu/maps
533565235
Page 6 of 14
[POP2004] * [WEIGHT]
46. Click OK to apply the Calculation.
47. Save
your work.
Summary Statistics
Now that we have a set of
Census Boundary files that
correspond to the watershed,
and estimates of the population
of those new boundary units, we
need to summarize those
population estimates for each of
our watershed units.
48. On the Attribute Table
Click the Options Button
and select Clear
Selection.
49. Close the Attribute Table.
50. Return to the ArcToolbox
Search Tab, enter
“summary” as the search
term and click Search.
51. Double-Click on the Summary Statistics
Tool.
52. Select the Union Layer as the Input
Table.
53. Browse to the
C:\temp\Intermediate_GIS_Skills\CT_
Watershed_Data.gdb and save the
Output Table as
“Population_Summary”
54. Select WTPOP as the Statistics Field,
and select SUM as the Statistic Type.
55. Select MAJOR as the Case field.
The Yale Map Collection
At Sterling Memorial Library
130 Wall Street, Room 707
Stacey Maples – GIS Assistant
203-432-8269 / stacey.maples@yale.edu
www.library.yale.edu/maps
533565235
Page 7 of 14
56. Click OK.
57. Click Close when the tool completes.
58. Click on the Source Tab, at the Bottom of the Table of Contents.
59. Right-Click on the Population _Summary Table and Open it to observe the population counts for the
watersheds.
60. Close Attribute Table.
61. Save
your work.
Joining the Summary Statistics Table to the
Watershed Boundary File
Ultimately, what we want is a CT_Major_Basins
Layer with the Population value as an attribute
of each feature. This is achieved through the
use of a table-to-table join.
62. Right-Click on the CT_Major_Basins
Layer and Select Joins and
Relates>Join…
63. Set the Options as shown in the image
to the right:
64. Click OK.
65. Right-Click the CT_Major_Basins Layer
and open its attribute table. Note that
the population counts have now been
joined to the boundary file.
The Yale Map Collection
At Sterling Memorial Library
130 Wall Street, Room 707
Stacey Maples – GIS Assistant
203-432-8269 / stacey.maples@yale.edu
www.library.yale.edu/maps
533565235
Page 8 of 14
Geocoding Address Data from a Table
Examine the Street Reference Data
1. Right-Click on the CT_Streets Layer
and Open the Attribute Table.
Note the fields included in this
reference data set. This streets
reference data is ‘topologically
integrated,’ meaning that there is
information encoded into the
dataset. Fields included for each
street segment that are essential to
geocoding process include:




the
FNODE – This is an identifying number for the point FROM WHICH the street segment
begins.
TNODE – This is an identifying number for the point TO WHICH the street segment
extends.
FRADDL & FRADDR – These are the values of the address range for the given street
segment at the FNODE for the LEFT & RIGHT side of the street, respectively.
TOADDL & TOADDR - These are the values of the address range for the given street
segment at the TNODE for the LEFT & RIGHT side of the street, respectively.
Together, the FRADDL, FRADDR, TOADDL & TOADDR values provide the numeric range of
addresses for both sides of a given street segment. This information is used to calculate the
“percent along” the street segment that a given address lays.
2. Close the CT_Streets table.
Examine the Address Data
3. If you are not still in the Source Tab of the Table of Contents, click on it.
4. Right-Click the
CT_TRI_Facilities table
and Open it.
Note that this table contains data
about facilities cataloged and
reported in the Toxic Relief
Inventory. The FStreet and other
fields prefixed with “F” are
attributes of the facility locations.
We will use these address
The Yale Map Collection
At Sterling Memorial Library
130 Wall Street, Room 707
Stacey Maples – GIS Assistant
203-432-8269 / stacey.maples@yale.edu
www.library.yale.edu/maps
533565235
Page 9 of 14
attributes to create an explicitly spatial dataset from a dataset with ‘implicit’ spatial data (street addresses).
Note also that the format of the addresses in the table differs from that in the reference street data. This
format, where the full street address is concatenated into a single field is how ArcGIS “prefers” address data.
5. Close the CT_TRI_Facilities table.
Examine the Address Locator
The Address Locator is an indexing device that “connects” your street reference data to your address data
by mapping the appropriate fields in each dataset to one another. The Address Locator also allows you to
“encapsulate” specific settings for how the data should be geocoded, so that you can provide an optimized
solution for repeatable geocoding of data.
6. Click on the
ArcCatalog Icon
Open ArcCatalog.
to
7. In the Catalog Tree, at
the left of the
ArcCatalog application,
Browse to the
C:\temp\Intermediate_
GIS_Skills\CT_Waters
hed_Data.gdb
database and find the
CT_Address_Locator
file.
8. Right-Click on the
CT_Address_Locator
and open it’s
Properties.
9. Note the mapping ot the attributes from
the CT_Streets reference dataset to the
necessary geocoding fields.
10. Note, also, that many of the setting can
be changed in this dialogue.
11. Click Cancel to close the Address
Locator Dialog.
12. Minimize ArcCatalog and return to ArcMap.
The Yale Map Collection
At Sterling Memorial Library
130 Wall Street, Room 707
Stacey Maples – GIS Assistant
203-432-8269 / stacey.maples@yale.edu
www.library.yale.edu/maps
533565235
Page 10 of 14
Starting the Geocoding Process
1. In the Source Tab of the Table of Contents, right-click
on the CT_TRI_Facilities table and select Geocode
Addresses…
2. Click Add and Browse to the
C:\temp\Intermediate_GIS_Skills\CT_Watershed_Data.g
db\CT_Address_Locator.
3. Click Add.
4. Click OK.
5. For the Address Input Fields, map the appropriate
fields as shown on the right:
6. For the Output Feature Class, suffix the default
value with “_01” so that it becomes
D:\Patrons_and_Projects\Stacey.Maples\Worksh
ops\2009 Workshops\02 - Intermediate GIS
Skills\Base\CT_Watershed_Data.gdb\Geocoding
_Result_01.
7. Click OK.
8. When the “Geocoding Addresses…” Status Window
finishes, click Rematch.
Investigating Unmatched Addresses
1. In the Interactive Rematch Dialog Box, right-click on
the Status Field header and select “Sort
Descending.” This will place all Unmatched records at
the top of the table.
2. Click in one of the cells for the first records to highlight
it.
3. Note the available Candidates in the lower panel.
Compare the values for these candidates to those of
your unmatched record.
4. Select the first candidate and click on the Match button.
The Yale Map Collection
At Sterling Memorial Library
130 Wall Street, Room 707
Stacey Maples – GIS Assistant
203-432-8269 / stacey.maples@yale.edu
www.library.yale.edu/maps
533565235
Page 11 of 14
5. Repeat until you have matched as many records as possible.
6. Click on the Close button.
Cleaning Unmatched Addresses from your results
1. Right-click on the Geocoding_Result_01 Layer and Open its Attribute Table.
2. Click the Options button and Select “Select by Attributes.”
3. Use the Query Builder to create a query
that reads:
"Status" <> 'U'
4. Click Verify, then Apply.
5. Click Close.
6. Close the Attribute Table.
7. Right-Click on the Geocoding_Result_01
Layer and Select Data>Export Data…
8. Note that the default in this case is to export
selected features, since we have an active
selection.
9. Under Output… Click on the Browse
Button, change the type to “File and
Personal Geodatabase Feature Class” and
save the export as
“C:\temp\Intermediate_GIS_Skills\CT_Wate
rshed_Data.gdb\CT_TRI_Facilities_Clean
_Geocodes.”
10. Click Save. Click OK.
11. Click “Yes” when prompted to add the data to the map as a layer and use the resulting layer’s
checkbox to turn on visibility.
12. Right-click and remove the Geocoding_Result_01 layer.
The Yale Map Collection
At Sterling Memorial Library
130 Wall Street, Room 707
Stacey Maples – GIS Assistant
203-432-8269 / stacey.maples@yale.edu
www.library.yale.edu/maps
533565235
Page 12 of 14
Counting Incidents Using “Spatial Join”
66. Right-Click on the CT_Major_Basins Layer and Select Joins and Relates>Join…
67. Change the First Drop-down to “Join Data from
another layer based on spatial location.”
68. Make sure CT)TRI_Facilities_Clean_Geocodes is the
layer to join.
69. Leave the default settings.
70. Save the Output as
C:\temp\Intermediate_GIS_Skills\CT_Watershed_Data
.gdb\CT_Major_Basins_Pop2004_and_TRI_Facility
_Counts.
71. Click OK.
72. Right-Click and open the Attribute Table of the
resulting CT_Major_Basins_with_Discharge_Count
Layer to note that a new “Count” Layer has been
added, with the number of discharge sites per
watershed unit.
73. Save
your work.
Working with Raster Data
Now, you will use raster data methods to create new measurements of proximity, between your
CT_Major_Rivers layer and your geocoded CT_TRI_Facilities. Remember that raster data is pixel based,
with each pixel containing the numeric value of some variable of interest. In this case, our variable of
interest is the distance to the nearest major river.
1. If it is not already, Open the ArcToolbox and click on the Search Tab.
2. Enter “distance” as your search term. Click Search.
3. In the results, look for the Euclidean Distance tool from the Spatial Analyst Toolset. Double-click to
launch the Euclidean Distance tool.
The Yale Map Collection
At Sterling Memorial Library
130 Wall Street, Room 707
Stacey Maples – GIS Assistant
203-432-8269 / stacey.maples@yale.edu
www.library.yale.edu/maps
533565235
Page 13 of 14
4. Select the CT_Major_Rivers
Layer as the Inpurt Feature
Source Data.
5. Change the Output Distance
Raster to
“C:\temp\Intermediate_GIS_S
kills\Data\Dist2River,” saving
the output to the
C:\temp\Intermediate_GIS_Sk
ills\Data\ folder created when
you unzipped the tutorial data.
6. Click on the Environments
button.
7. Click on General Setting to
expand the item, and set the
Extent to “Same as CT_Block_Groups”
8. Click OK.
9. Click OK, again.
10. Turn the visibility of the resulting layer
on, if it is not enabled by default.
Note that you have created a new raster
layer, whose pixels have the value of the
distance to the nearest feature in the
ST_Major_Rivers layer.
Extracting Raster Values to Points
Ultimately, we would like to make the “Distance
to River” an attribute of each or our Toxic
Release facilities. Here we will use the Extract Values to Points tool to do just that. This tool will take a set
of points and make the value of the raster pixel, or cell, that is directly beneath that point, an attribute of the
point.
1. Return to the ArcToolbox panel and Search on the term “Extract Values.”
2. In the results, double-click on the Extract Values to Points tool from the Spatial Analyst Toolbox.
3. Select the CT_TRI_Facilities_Clean_Geocodes layer as the input point feature layer.
The Yale Map Collection
At Sterling Memorial Library
130 Wall Street, Room 707
Stacey Maples – GIS Assistant
203-432-8269 / stacey.maples@yale.edu
www.library.yale.edu/maps
533565235
Page 14 of 14
4. Select the dist2river layer as the input raster.
5. Change the Output Point Features to
“C:\temp\Intermediate_GIS_Skills\CT_Watershed_Data.gdb\CT_TRI_Facilities_Clean_Geocodes_
with_dist2river”
6. Check the Interpolate values… option.
7. Click OK.
8. Dismiss the Datum Warning.
9. Right-click on the new CT_TRI_Facilities_Clean_Geocodes_with_dist2river layer and open it’s
attribute table.
10. Scroll to the far right of the table and note that the RASTERVALU field is populated with the
interpolated distance value for the raster cell that each point falls inside.
Setting Relative Pathnames & Making ArcMap Projects Portable
By setting “Relative Pathnames” in File>Map Properties>Data Source
Options, you can move your ArcMap Project Folder as a single unit,
preserving the location of your data files relative to your MXD
document, without breaking the internal links to the datasets. You
can also Zip the folder and send it through the email to colleagues.
1. On the Main Menu, Go To File>Document Properties.
2. Click on the Data Source Options Button.
3. Set the Option to “Store relative path names to data
sources.”
4. Check the “Make relative paths the default for new map
documents I create” Checkbox, if it is not already.
5. Click Ok.
6. Click Ok.
You can now move your project by copying or zipping the C:\temp\Intermediate_GIS_Skills\ Folder, in its
entirety, without having the problem of broken links that we experienced at the beginning of the tutorial.

ArcMap supports long filenames for MXD Document, table and shapefile names. Use this to your
advantage by giving these files very specifically descriptive names. Coverage and raster filenames
are limited to 13 characters.
The Yale Map Collection
At Sterling Memorial Library
130 Wall Street, Room 707
Stacey Maples – GIS Assistant
203-432-8269 / stacey.maples@yale.edu
www.library.yale.edu/maps