Texas A&M University 1
Department of Civil Engineering
Introduction to ArcGIS 10
Francisco Olivera, Ph.D., P.E.
Srikanth Koka
Lauren Walker
Aishwarya Vijaykumar
Department of Civil Engineering
Texas A&M University
December 5, 2011
Contents
Brief Overview of ArcGIS 10 ............................................................................................................ 2
Goals of the Exercise ....................................................................................................................... 2
Computer and Data Requirements ................................................................................................. 2
Procedure ........................................................................................................................................ 2
1. Creating Geodatabases, Feature Datasets and Feature Classes ......................................... 3
2. Displaying Spatial Datasets in a Map ................................................................................... 5
3. Accessing Attribute Data ..................................................................................................... 7
4. Selecting Objects of a Geodatabase Table (points, lines and polygons) ............................. 9
5. Making a Chart .................................................................................................................. 11
6. Consolidating Your Results for Presentation ..................................................................... 12
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Brief Overview of ArcGIS 10
ArcGIS 10 is a geographic information systems (GIS) platform developed by Environmental
Systems Research Institute (ESRI). It provides the tools to compile, use, and manage geographic
information. It includes comprehensive professional GIS applications that support a number of
GIS tasks, including mapping, data compilation, analysis, geodatabase management, and
geographic information sharing. The three main components of ArcGIS 10 are ArcCatalog,
ArcMap, and ArcToolBox. ArcCatalog is used for browsing for maps and spatial data, exploring
spatial data, viewing and creating metadata, and managing spatial data. ArcMap is used for
visualizing spatial data, performing spatial analysis, and creating maps to show the results of
your work. ArcToolBox is a “wizard” that contains all the available ArcGIS 10 tools, including
data conversion tools, data management tools, and limited data analysis tools. All parts of the
ArcGIS system have integrated online functionality, and the system includes online maps and
geographic information.
Goals of the Exercise To introduce you to ArcGIS: ArcCatalog and ArcMap.
Computer and Data Requirements
To complete this exercise, you will need ArcGIS 10.
You will be working with the following spatial datasets: a polygon shapefile of the Counties of
Texas called “Counties” and a point shapefile of pan evaporation stations called “Evap.” These
shapefiles consist of seven files each – evap.dbf, evap.prj, evap.sbn, evap.sbx, evap.shp,
evap.shp.xml, evap.shx, Counties.dbf, Counties.prj, Counties.sbn, Counties.sbx, Counties.shp,
Counties.shp.xml, and Counties.shx. Download the Ex1Data.zip file containing the data, which is
in the same folder where this document is located. Unzip or extract it and save the files to a
working directory on your computer. Make sure to remember the location of these files so that
you can access them later.
Procedure
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Note that the following procedure is a general outline that can be followed to complete this
lesson. However, you are encouraged to experiment with the program and be creative.
1. Creating Geodatabases, Feature Datasets and Feature Classes
A geodatabase is a relational database that stores geographic information. In turn, a relational
database is a collection of tables logically associated to each other by common key attributes. A
geodatabase can be considered a relational database that can store geographic information
because, besides storing numbers or strings in the attribute columns, it can store features or
geometric objects (i.e., polygons, lines or points) with defined shape and location. A
geodatabase has an extension mdb. Tables in a geodatabase are called object classes. A feature
class is a special type of object class that contains features. Thus, a feature class is a collection of
features that have the same behavior and the same set of attributes. Note that feature classes
do not need to be stored inside a feature dataset, and can be stored as stand-alone classes in
the geodatabase. A feature dataset is a collection of feature classes that share the same spatial
reference. The spatial reference describes both the projection and extent for a feature class in
the geodatabase.
a. Creating a new geodatabase:
(1) Open ArcCatalog.
(2) On the left panel, search for the folder where you want to create your geodatabase. If
the folder is not displayed here, right click on Folder Connections in the left panel and
select “Connect Folder.” Select the appropriate folder.
(3) Right click on the folder name or icon.
(4) Click New/Personal Geodatabase; a new geodatabase called New Personal
Geodatabase.mdb (represented by a cylinder-shaped icon) will be created.
(5) Overwrite the name of the geodatabase with Ex1Data (the geodatabase will keep its file
extension .mdb regardless of whether or not you include it in the name).
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b. Adding data to the Ex1Data.mdb geodatabase within a feature dataset
(1) In ArcCatalog, right click on the name or icon of Ex1Data.mdb.
(2) Click New/Feature Dataset
(3) Name the new dataset Texas and click Next.
(4) Choose the coordinate system for this dataset in this window. Click Import, and browse
for the shapefile Counties and click Add. Click Next twice and then Finish. This gives your
Feature Dataset the spatial extent and projection of Counties. Data should not be added
to a feature dataset before its spatial extent and projection are defined.
(5) Right-click on the name or icon of Ex1Data.mdb\Texas
(6) Click Import/Feature Class(multiple)
(7) Locate and add the Counties and Evap shapefiles and Add both to the Feature
Class(multiple) window and click OK
After creating the geodatabase, the feature dataset, and the feature classes, the ArcCatalog tree
in the left pane should look like this when all the “+” boxes are clicked:
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Note that the feature classes Counties and Evap could have been created outside the feature
dataset Texas; but, because they share the same spatial extent, they were grouped together.
In ArcCatalog, you can toggle the right panel display between a file tree (Contents tab), a data
view (Preview tab), and a metadata document (Description tab). The preview option allows you
to display the feature class shapes and table, by selecting geography or table at the bottom of
the panel. You may now close the ArcCatalog program.
2. Displaying Spatial Datasets in a Map
In ArcMap, a layer consists of a reference to a spatial dataset (such as a feature class, shapefile
or coverage) and a definition of how to display it (legend colors, line thickness, etc.), and a map
is a graphical representation of geographic information. The left panel in the ArcMap window
shows the Table of Contents, and the right panel is the Display Window. The Table of Contents
lists layers and the Display Window displays maps.
A. Displaying the spatial data of the Texas feature dataset in a map
(1) Open ArcMap and then click on the Add Data button in the toolbar under the menu
bar. Alternatively, click on File/Add Data/Add Data from the dropdown menu.
(2) Browse to the feature dataset Texas and click Add. You can also add each feature class
in the Texas feature dataset separately.
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Note that the Table of Contents lists the layers corresponding to the two feature classes of the
Texas feature dataset that you just added, while the Display Window displays the map with the
corresponding spatial data (i.e., Texas counties and evaporation stations).
(3) Save your work in a Map Document. Click File/Save, navigate to your working directory,
and name the file ‘GISWREx1’ (the file will automatically be assigned the extension
mxd).
B. Modifying the display of the Counties layer in the map
(1) Right click on the Counties layer name and click the Properties… menu button.
(2) Click the Symbology tab and then click on the button showing the symbol; the Symbol
Selector window opens. Make your selections for the Fill Color, the Outline Width, and
the Outline Color, and click OK.
(3) Click OK again. Follow the same procedure to modify the display of the Evap layer. The
new map hopefully looks better than the original one.
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3. Accessing Attribute Data
Numerical and text information stored in the fields of the geodatabase tables is called attribute
data.
A. At a specific location in ArcMap
(1) In ArcMap, make the layers Evap and Counties (assuming you want to retrieve
information of both layers) visible and then click on the Identify tool in the Tools
toolbar. If this toolbar is not displayed, turn it on by going to Customize/Toolbars/Tools.
(2) Click the location on the map in which you are interested.
(3) The Identify Results window will open, in which the attributes of only the top most layer
are displayed.
(4) To display the attributes of the features of both layers at a location in the map, in the
Identify Results window, select All layers in the Layers dropdown list.
(5) Start clicking on locations that interest you on the map. In the figure, attribute data for
the evaporation station in Lake Colorado City and Mitchell county have been retrieved;
however, because Mitchell county is highlighted, the bottom panel of the Identify
window displays attribute data of the evaporation station. You have to highlight the
area number under Counties to get the attribute data for the specific.
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B. Of an entire layer
(1) In ArcMap, right click on the Evap layer name in the Table of Contents.
(2) Click Open Attribute Table. This tables contains the attribute data of the layer and
contains a field called Shape. The Shape field displays the words “Point,” “Line” or
“Polygon,” but really stores a geometric object with the shape and location of a point,
line, or polygon.
Note that record number 17 corresponds to the Lake Colorado City evaporation station. All
attribute data shown in the table is the same as previously retrieved using the Identify tool.
C. Calculating the statistics of a field
(1) In ArcMap, right-click on the header of the ANN_VAL field in the attribute table for
Evap (ANN_VAL contains annual evaporation data).
(2) Select Statistics, and a statistics chart is displayed in a separate window. You can change
the field for which statistics are calculated in the Statistics of Evap window.
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(3) Close the attribute table and statistics window when finished looking at them.
4. Selecting Objects of a Geodatabase Table (points, lines and polygons)
Selecting objects of a geodatabase table refers to identifying a subset of objects in the
geodatabase table for a specific purpose. Object selection can be made from a map by
identifying the geometric shape or from an attribute table by identifying the record. Regardless
of how you select an object, both the shape in the map and the record in the attribute table will
be selected when you select either one.
A. Selecting an object from the map
(1) In ArcMap, right click on the Counties layer, and then click Selection/Make This The
Only Selectable Layer. This allows you to only select features within the Counties layer.
(2) Click on the Select Features tool in the Tools toolbar. In the display window, click on
the Counties polygon(s) you want to select. To select more than one object, press and
hold the Shift key and while you click on additional objects. Selected objects are
displayed with a light blue outline, although the color might change depending on your
settings (to change the settings, click Selection/Selection Options/Selection Tools
Settings). The corresponding attribute table records will also have been selected. You
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can verify this by opening the Counties attribute table and checking whether they are
highlighted.
(3) To clear your selection, right-click on the layer name, and choose Selection/Clear
Selected Features.
B. Selecting an object from the attribute table
(1) In ArcMap, click on the layer name Counties in the Table of Contents and select Open
Attribute Table.
(2) In the Attribute Table, click on the square to the left of the records you want to select.
To select more than one record, press the Ctrl key and hold it down while you click on
additional records. Selected records are displayed with a light blue background,
although the color might change depending on your settings. The corresponding objects
in the map have also been selected. You can verify this by returning to the map window.
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(3) To clear your selection, click on the Options button in the Attribute Table window,
and choose Clear Selection. Close the table.
5. Making a Chart
A chart of one or more records selected from a geodatabase table can be plotted. Follow the
directions below to plot the monthly evaporation of one or more stations.
(1) In ArcMap, select one or more evaporation stations from the Evap layer. If you want to
select features directly from the map, make sure to define the appropriate layer (in this
case, the Evap layer) as a “selectable layer” by clicking on Selection/Make This The Only
Selectable Layer menu. Otherwise, select from the attributes table as described
previously.
(2) Open the attribute table of the Evap layer. In the Attribute Table for Evap, click on the
Options button and then Create Graph...
In the Create Graph wizard, select Vertical Bar as the Graph type and Evap as the Layer/Table.
Select check the field JAN_VAL from the dropdown menu for Value field. Select Custom under
Color. Click Next. Click the radio button next to Show only selected features/records on the
graph. Now, click Back. Click on Add/New Series and select the field FEB_VAL under the Value
field and change the Color to Custom. Repeat for MAR_VAL to DEC_VAL. Set X Label Field as
STAT_NAME. You can rename the Series by double clicking on the tabs containing their names.
Click Next. Overwrite the Title field with Evaporation, browse through the Axis properties, make
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the necessary changes. (Once you click the Finish button, you cannot make changes to your
graph. If you close this window, you will have to create your graph from scratch). Click Finish.
You will obtain a graph similar to the one shown below. Do not close this window; this graph is
not saved anywhere and will be lost if you close the window.
Note that the charting capabilities of ArcMap are not as developed as those in other
applications. To prepare charts that are more complex you can export your tabular data to other
applications.
6. Consolidating Your Results for Presentation
To consolidate a map of Texas Counties with evaporation stations with the graph that you
created before on a single sheet of paper, follow the directions.
(1) In ArcMap, change the format of the display window from Data View to Layout View by
clicking on Layout View in the View dropdown menu.
(2) Reduce the size of the data frame (i.e., rectangle where the spatial data is contained), to
make room for the graph, by clicking on the page and moving its handlers.
(3) Right click on the graph and select Add to Layout. You can move and resize the graph as
necessary.
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Your final map should look like this:
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These materials may be used for research and educational purposes only. Please credit the
authors and the Department of Civil Engineering, Texas A&M University.
All commercial rights reserved. Copyright 2011: Texas A&M University.