Center for Research in Water Resources
University of Texas at Austin
exercise introduces you to ArcMap and ArcCatalog. You use these applications to
create a map of pan evaporation stations in
To carry out this exercise, you need to have a computer, which runs ArcGIS Desktop version 10.2. You will also need and ESRI Global Account to enable you to login to ArcGIS Online. If you do not already have an ESRI Global Account, go to: https://www.arcgis.com/home/createaccount.html and create one.
In the first part of this exercise using ArcGIS Desktop, you will be working with the following spatial datasets:
These shapefiles consist of several files (e.g. evap.dbf, evap.shp, evap.shx). You can get them from this zip file: http://www.ce.utexas.edu/prof/maidment/giswr2013/Ex1/Ex1Data.zip
You need to establish a working folder to do the exercise on. This can be in c:\temp, your student directory, or on a memory stick attached to the machine you are working on. If you don't yet have a regular Login account at the Civil Engineering Learning Resource Center, get a temporary guest login to do the exercise.
After you have downloaded the zip file Ex1Data.zip double click on the file and you should see the Winzip, Alladin Stuffit utility, or other zip utility to open the file on your computer (if it doesn’t open you’ll have to unzip this file on a computer that has a zip utility installed). Extract all files from the zip file to the working folder that you’ve set up to do this exercise. You should end up with a file list that looks something like this. You may see these data within a sequence of folder names, and if so, click on each folder down through the sequence until you locate the required files.
Please note that the following procedure is a general outline, which can be followed to complete this lesson. However, you are encouraged to experiment with the program and to be creative.
A shapefile is a homogenous collection of simple features that do not contain topological information. A shapefile includes geometric features and their attributes. The attributes are contained in a dBase table, which allows for the joining with a feature based on the attribute key.
Open ArcMap and select the A new empty map option. If you are using Windows 7 or Windows XP, hit the Start button and you’ll see a series of options for ArcGIS. Select ArcMap.
If you are using Windows 8, you’ll see in your Windows display. If you don’t see that, then just type “ArcMap..” and you’ll see the program symbol appear.
Use the Add Data button to add the data for this exercise to the ArcMap display.
Navigate to the folder, which contains the data, and select all three files at once by using the shift key. Click the Add button to import the data. If you are using a network drive to obtain your files use the Connect to folder button to add the network drive to the ones that ArcMap is accessing so you can get to the files.
Click on each of the
three shape files so that they are highlighted
and add them to your ArcMap display.
All the themes are highlighted and Texas lies above counties so you cannot see the counties theme. Click on the List by Drawing Order button in the Table of Contents page:
Click in the Table of Contents area below the feature class names so that three themes are no longer highlighted, then click on the counties theme and drag it up so that it is located above the Texas theme. You’ll then get a display showing the counties.
To change the appearance of a map display, you can access the Symbology menu just by double clicking on the Symbol
displayed in the ArcMap Layers, and you’ll get the Symbol Selector window
Click on the symbol color box, make your selections for the Fill Color and the Outline Color, and click OK, twice. You can show the outline of the State of Texas more distinctly by using the No Color
symbology for the Fill Color and then changing the Outline Color to Green and the Outline Width to 2.
Drag the Texas layer above the Counties layer, and you’ll see that the Counties are not obscured as they were before and the State of Texas is highlighted with a nice Green outline! We are green in Texas! If you have another color for your Counties, then click on the Counties symbol in the Legend and in the Symbol Selector window that appears select a nice green color and hit Ok to recolor your counties.
To Save this map display, use File/Save As in ArcMap and save the resulting file as Ex1.mxd.
Save your work in ArcMap by choosing File/Save and, after navigating to your working directory, naming the file Ex1 (the file will be assigned the extension mxd). When you do this, the Ex1.mxd file contains the file location of the geodatabase and the symbology you’ve chosen for the map display. You can shut down Arc Map and then invoke Arc Map again and reload the same map display by clicking on Ex1.mxd. Note, however, that if in the mean time you’ve relocated your data, ArcMap will go back to where you had it at the time the map file was saved.
If you open your ArcMap Ex1.mxd file later from another location in your file system, you may see a red exclamation points beside your feature classes. If this happens, in ArcMap, right click on the feature class use Data/RepairData Sources to relocate the file location where the corresponding data are now stored and your map will display correctly again.
Open ArcCatalog by clicking on the Catalog tab on the right hand side of the map display
Click on the “Folder Connections” button and navigate to where your data are stored.
If you right click on a data layer, you can obtain an Item Description
Select the Preview tab and then Geography to see a map of the feature class
And then select the Table view
The attributes FID, Shape, Area and Perimeter are standard attributes for ArcGIS feature classes. The units of the area and perimeter are defined from the map units of the feature class.
If you right click on a feature class and then select Properties
And select XY Coordinate System which shows you the parameters of the coordinate system of these data, NAD83, or the North American Datum of 1983. This provides a rather complicated set of parameters that we’ll learn more about later.
If you click on the Fields tab, you’ll see a formal definition of each attribute field with its Field Name and Data Type. In this case, ObjectID means a special data type that indexes each feature as an object in the GIS, Geometry means that the Shape field has geographical coordinates stored in it, and Float and Double mean decimal numbers in single or double precision, respectively. There are some other data types such as Short and Long integers, Text and Date types, that we’ll encounter later in the course.
Click on the other two data layers, Evap and Texas to preview them also.
Up to this point we have just used local GIS data in our display. Let’s instead using base maps from the ArcGIS Online. Use Add Basemap:
Click on “Streets”, in the bottom row of maps. You’ll see a background map appear behind your Texas display. Pretty cool!
If you get a message
asking about Hardware Acceleration, say Yes
You should see a result like that shown below. If your BaseMap does not show up, use the Refresh tool in the bottom left hand corner of the ArcMap display to redraw the map and the BaseMap should then show up.
To quickly get the map to center on Texas, right click on the Texas layer and select Zoom to Layer
Click on the Counties theme and use the Symbol Selector to change the Fill Color to “No Color” so we can see through it to the background map, and the new display appears. Let’s examine Travis County.
Use the Zoom in button to select a box around Travis County
Zoom in to Travis County by Austin in the center of Texas, and let’s examine the evaporation site by Lake Travis to the Northwest of the city. Notice how more interesting information appears as you zoom in closer.
Let’s label the sites with their names. Right click on the Evap theme and select Properties at the bottom of the display that appears.
Labels tab and for the Label Field, select Station, and 16 point as the type size. Hit Apply and then Ok, to close this window.
Now, right click on the Evap theme again and select Label Features, and you’ll see a nice label Mansfield Dam appear by the site next to Lake Travis.
Click on the symbol for the Evap points and use the Symbol Selector to change the size of the points to 8 and the color to Red. Now we’ve got a nice map that shows the location of our observation site labeled with its name.
If you zoom in a bit closer, you can see just where the site is located near Lake Travis. Mansfield Dam is the dam that is at the downstream end of Lake Travis. You can even see the access roads you’d use to go to this site.
Now, let’s look at some imagery for this location. Proceeding as you did before to get the Street map, use Add BaseMap, to add data for Imagery Turn off the Street Map so you can see the imagery.
And now you’ll see the same information displayed against a background map of orthoimagery, and let’s zoom in a bit to see more detail. For the Evap theme, I have used the Properties/Label to change the color of my site labels from black to blue to make them easier to see against the image background. This is really cool stuff! You can really get a sense of context about where this observation site is located.
Use File/Save As to save this new map display as Ex1.mxd so that you can get it back later if you need it.
Let’s go back to the view we had earlier of Travis County. Use the Go Back to Previous Extent arrow
to step back through the views we have just been working on, and turn off the Image basemap so that you can see the Streets basemap again. Change the Label color for the evap sites back to Black.
Numerical and text information stored in the fields of the geodatabase tables are called attributes. To access attribute data of the feature classes at a specific location:
Click on the Identify tool
Highlight the feature class you are interested in the Table of Contents (Evap), and then click on the feature on the map you are interested in. In the Identify window that pops up you’ll see the attributes of that particular feature. In this instance, what you see is that the data for Lake, cover the range from 2003 to 2010, the latitude and longitude are 30.403 and -97.917, and the values from Jan through Dec are the mean monthly evaporation recorded at this location, in inches, whose annual total is an Annual of 69.36 inches.
These are pan evaporation data recorded using an instrument like that shown below. The evaporation data were obtained from the Texas Water Development Board. Only data from 2001 onwards is used since the TWDB has quality control checked that information. Monthly evaporation is found by averaging the daily values of evaporation read from the pan, and multiplying by the number of days in the month. If a month has fewer than 20 daily values recorded, it is excluded from the dataset. Only years with valid monthly data for all 12 months are used in computing the mean monthly and mean annual pan evaporation data shown in the attribute table.
Viewing an Attribute Table
To access attribute data of an entire layer, in ArcMap: right click on the Evap layer name in the table of contents, and select Open Attribute Table:
And if you scroll down the resulting Table and click on FID 24 you’ll see the record that contains the attributes of the Lake Travis station that you identified earlier. Click on this to select it, and you’ll see the corresponding point selected in the map – this is a key idea of GIS – map features are described by records in attribute tables.
To Clear a Selected feature and select a new one, use: Selection/Clear Selected Features in the ArcMap toolbar:
Selecting features from a feature class involves choosing a subset of all the features in the class for a specific purpose. Feature 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. Make sure that the Evap theme is highlighted in the Table of Contents and then Click on the Select Features by Rectangle tool
If zoom back a little bit and drag a box over the three evaporation sites in the Highland Lakes reservoir system,
you’ll see both records highlighted on the map and in the attribute table. I’ve turned off the Counties layer and used Show selected records at the bottom of the Attribute Table to just show the three highlighted stations.
To clear your selection, choose Selection/Clear Selected Features.
Clicking on Show all records, then displays all the records in the attribute table again.
Let’s suppose we want to map the values of annual evaporation recorded at the stations, rather than just symbolizing them by their location. Right click on the Evap layer and select Properties/Symbology
Show Quantities/Graduated Symbols with the Value field of Annual, and make the Template color blue.
I have turned off all the other layers and added the Topographic base map to get the image below. Very cool!
You can see from the map that there is some tendency for lower evaporation values near the coast and to the East and higher values to the West. Charts are useful because they allow you to visualize trends in data. Click on Table Options
at the top left of the Table and select Create Graph.
You will be making a Vertical bar chart (the default option). The next screen will allow you to indicate the data to be used in the graph. Here is a graph of the Annual Evaporation (Annual) of all the stations plotted against the Longitude of the station. You can see that there is a general trend of the evaporation increasing as you go from East to West in Texas. The color of the chart bars is blue, the same as the map points.
Click off “Add to Legend” to get rid of the legend on the right hand side.
Hit Next and edit the graph properties to make them nicer. Add a title Evaporation and Longitude and relabel the vertical axis Evaporation (Inches)
Click Finish, and you’ve created a graph linked to mapped features in ArcMap. If you create the same kind of graph for Evaporation and Latitude, you can see that there isn’t a tendency for evaporation to vary with latitude in Texas, as there is for variation of evaporation with longitude.
Save your ArcMap document Ex1.mxd so that you can retain this display.
Graphing in Excel
Another graphing option is to make a chart in Excel using the dBase tables given by the evaporation shapefile. Open the evaporation attributes table Evap.dbf as a table in Excel. Use Files of Type: dBase files in Excel to focus only on .dbf tables when you open the table.
When you open the file, you’ll see that the Station name is very wide (254 characters). Right click on this column in Excel and select Column width of 30 characters to correct this.
Select the stations you want to plot, copy their records to a new worksheet, delete the columns you don't need there, and then create a chart. Here is an example chart created this way.
Now we are going to create a formal map of evaporation in Texas that includes the charts that we’ve created.
Change the format of the display window from Data View to Layout View by clicking on View/Layout View,
If nothing shows up in your layout, hit Focus Data Frame to put your map in the Layout Window.
Reduce the size of the data frame in the layout (i.e., rectangle where the spatial data is contained) -- to make room for the graph -- by clicking on the map and moving its handlers. If you have a zoomed in view in Arc Map, you’ll get the same image in in the Layout. To move the location of your map, go back to the Data View and use the Pan tool
to move your map around. When you switch back to the Layout View the new map location will be displayed.
I have turned off the Basemap to make the map easier to interpret.
Keep saving your ArcMap document as you proceed through the map making steps so that if you mess up something you can get back the work you’ve already done.
To insert the ArcMap Chart into the Layout, right-click on the upper blue bar at the top of the Chart and select Add to Layout. Move and resize the graph as necessary. If you want to copy your graph from Excel, highlight the graph, and click on Copy in Excel, then Paste in ArcMap and your graph should appear in the map layout.
You can also insert a North Arrow and a Scale Bar by using the Insert
menu in ArcMap.
When you put up the scale bar you can select the distance units to be displayed. I have used miles.
You can add a Title or Text with the text tool shown next to the line draw tool. The text displays in very small font sizes. Select and click on them, and use Properties to resize them.
Your map might look like this:
You can export your map from ArcGIS using File/Export Map from the ArcMap menu, and you can store this as Ex1.emf in your data file. Then you can add it to a Word document using Insert/Picture/From File and load this emf file, as shown below. Pretty cool!
Then you can add it to a Word document using Insert/Picture/From File and load this emf file, as shown below. Pretty cool!
A more general procedure
is to simply copy the screen to the clipboard and crop out the part that you
want, saving it to a file for later use. That is how all the images in this
exercise were prepared. To copy any image, use the Snipping Tool in All Programs/Accessories on your
Windows Desktop interface
Drag the cursor around the area that you want to capture and you’ll see it copied into a new display, then use Paste to insert this snippet into a specific location in your document. If you only want to capture the active frame, press Alt + Print Screen and then Paste it to the new document.
This approach can also be used to add a map to a chart in Excel:
The manipulations just described transfer objects from one application to another.
To be turned in: An ArcMap map layout in it showing a map of Texas with gages, coupled with a graph showing monthly evaporation data plotted from the gages. In the presentation of information on maps and charts it is important to include sufficient labeling detail so that the information can be clearly and unambiguously interpreted. You should include a scale bar to indicate distance, a north arrow to indicate direction and labels or legends with units wherever they are needed to interpret map or quantitative values.
Now, let’s suppose
that you don’t have ArcGIS Desktop and you want to make a map anyway. Let’s
do this in ArcGIS Online. You can make a map in ArcGIS Online without an ESRI
Global Account, but if you want to save the map and share it with others on the
web, you have to have an ESRI Global Account to do that. If you don’t
have and ESRI Global Account, go to https://webaccounts.esri.com/cas/index.cfm
and create an account. For “Organization” use “University of
Texas at Austin” or “Utah State University”, whichever is
more appropriate for you. To execute this part of the exercise you need to have
(1) A Comma Separated Variable (CSV) file of Texas Pan Evaporation: http://www.caee.utexas.edu/prof/maidment/giswr2013/Ex1/AGOL/TexasPanEvap.csv
(2) A zipped shape file of Texas Counties: http://www.caee.utexas.edu/prof/maidment/giswr2013/Ex1/AGOL/Counties.zip
Go to http://www.arcgis.com and sign in with your ArcGIS Online Username and Password
Click on to bring up a Topographic Map of the United States to which we’ll add the pan evaporation data. I have created a New Folder called GISWR2013 to store information in from this class and to keep this separate from what I have done in ArcGIS Online for other purposes.
A topographic map of North America opens up. Zoom in to Texas. You can press “Shift” and then use your mouse to drag a box across Texas to facilitate zooming in.
Add a Layer from File
Choose TexasPanEvap.csv and click Import Layer
You’ll see the points added to the map. This happens because the .csv file has the Latitude and Longitude of the points in decimal degrees:
Now, let’s Change Symbols on the map.
Use Size as the discriminator and Annual as the Attribute to show. This value is the annual pan evaporation in Inches.
Hit Apply and Done Changing Symbols and you’ll see a new map, and if you click on one of the observation sites, you can see the data values at that point.
Ok, this is pretty cool. You’ve just created a web map with your own data in it. Now, let’s save the map into your ArcGIS Online workspace:
I have given my map a title, some tags by which it can be discovered and a description.
Now if you look in Home/My Content,
You’ll see that you have the new map stored there.
If you click on the Texas Pan Evaporation map title, you’ll see a window open that tells you about this map, and if you open this in the ArcGIS.com map viewer, you’ll see your map again as you had it before. Hence, if you inadvertently close your web browser wherein you are creating this map, nothing is lost.
Let’s Configure the Pop-Up that it shows just selected attributes, and also a chart of monthly pan evaporation. Hit Configure Attributes.
Select Station and all the monthly and annual evaporation values. Hit Save Pop-up. Now, your map will show a reduced set of attributes when you click on a point.
Now, Configure the Pop-Up again, and let’s add a Line Chart
Make the title “Monthly Pan Evaporation” and select all the monthly pan evaporation values to display. Click Ok to apply these choices. And Save Pop-Up to get the new chart in the Pop-Up display.
And now when you click on a point you get rather a nice chart, which along with the annual value of pan evaporation tells you the total evaporation and gives an image of how it is distributed over the year.
Now, let’s add the Counties layer to provide some more spatial context for the observation points
We’ll add the Counties as a zipped file of the Counties shape file.
When the Counties layer displays, it is the first layer on top of the map and it obscures the pan evaporation points.
The Counties layer can be moved down so that the points are more clearly displayed
And if you set the Transparency of the Counties layer to 75%, a rather pleasant map appears:
Let’s Save the map so we can retrieve it in this condition again.
Now, let’s suppose we want to Add some Notes on this map.
Just accept the template as it is presented to you using Create
Add Stickpins to highlight the Pan Evaporation Sites at Lake Travis and Lake Ivie, both important water supply lakes on the Colorado River in Texas.
Now let’s suppose you want to Share this map with colleagues online.
I am a member of a number of Groups in ArcGIS Online, and I could choose just to share my map with one or more of those, but instead, let’s share the map to Everyone (public), and that way anyone can see it. I get back a web link for this http://bit.ly/17zT5BM
And if I put this address into a web browser, my map appears again! Ok, this is pretty cool. I’ve created a map on the web and shared it with others.
Two things to
(1) Make sure that you have saved your map zoomed out so that a user can see all of Texas in it, rather than zoomed in to some location.
(2) Make sure that you have used “Share” to make your map accessible at least to the UT Austin Organization if not Publicly so that I can view it and grade it. Otherwise, I won’t be able to see it.
To be turned in: The web link (equivalent to my http://bit.ly/17zT5BM) for your map so that I can view it online.
(1) An ArcMap map layout in it showing a map of Texas with gages, coupled with a graph showing evaporation data plotted from the gages. In the presentation of information on maps and charts it is important to include sufficient labeling detail so that the information can be clearly and unambiguously interpreted. You should include a scale bar to indicate distance, a north arrow to indicate direction and labels or legends with units wherever they are needed to interpret map or quantitative values. Let’s see some nice cartography!!
(2) The web link (equivalent to http://bit.ly/17zT5BM) for your map so that I can view it online.
The assignment is due in a week from the date it was assigned in class. Please save your solution as a .pdf file and email it to me ( firstname.lastname@example.org ).