Introduction to ArcGIS 10 - Texas A&M Universityceprofs.tamu.edu/folivera/GIS-CE/Fall2012/GIS Tutorials...Texas A&M University 1 Department of Civil Engineering Introduction to ArcGIS

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


Department of Civil Engineering 2

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



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).



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:



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.



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.



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.



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.



(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



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.



(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



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.



Your final map should look like this:



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.

Documents

Introduction to ArcGIS 10 - Texas A&M Universityceprofs.tamu.edu/folivera/GIS-CE/Fall2012/GIS Tutorials...Texas A&M University 1 Department of Civil Engineering Introduction to ArcGIS