Arizona NEMO
Internet Map Services Workshop

Kristine Uhlman, Phil Guertin,
Patrick Barabé, Lainie Levick

Objectives

• Overview of NEMO IMS website
• Introduction to Geographic Data
• Elements of the ArcIMS HTML viewer
• Hands-on Tutorials with the IMS Toolbar
• Understanding Queries
• Making and Printing Maps
• Compile a Glossary (ongoing)

Arizona NEMO IMS Resources

Main Website: http://www.srnr.arizona.edu/nemo/ims/

Also Available via the IMS link on the main Arizona NEMO website (www.arizonanemo.org)

• Interactive Internet Map Services
• Help: Using the IMS Website
• Help: Toolbar Quick Help
• IMS Workshop presentation (this document)
• Links to partners and other web mapping resources

Introduction to Geographic Data: Definitions

Introduction to Geographic Data: Layers

• Layers represent geographic phenomena that share a common pool of attributes.
• Layers are also known as themes
• Layers are usually associated with tabular data.
• Examples:
  • USGS Gages
  • Rivers
  • Counties

Introduction to Geographic Data: Features

• Layers are comprised of multiple features.
• Features represent discrete objects or locations defined by coordinates.
• Features are associated with individual records in a table

Introduction to Geographic Data: Features

• Point Features - Locations represented by a single coordinate (lat/long)
  • USGS Gages
  • Cities/Towns
• Line Features - Objects on the ground represented by a list of coordinates.
  • Rivers
  • Roads
• Areas - Objects on the ground represented by a set of coordinates that define perimeter and area.
  • Watersheds
  • Census Blocks
  • Cities/Towns

Introduction to Geographic Data: Features and Scale

• Q: In the previous slide, why are cities and towns listed under both points and areas?
• A: The scale of a map can change the way features are represented.
• Consider how Tucson city limits would look if you compare an 8^1/2 x 11 map of Pima County vs. a map of the United States.

Introduction to Geographic Data: Images and Surfaces

• Generally, GIS surfaces do represent data, however in the context of IMS, they are generally presented as mere images.
• In this context, images provide contextual clues to us, the users, but do not provide searchable data.
• Examples:
  • Relief
  • USGS Topos

IMS Website Elements

Activities: Working with The Toolbar

The Toolbar: Zooming

1. Click Zoom In (or Zoom Out) on the toolbar.
2. Move the mouse pointer to the desired location on the map, then click and drag a box around it.
3. Release the mouse button. The map display zooms in to or out from the selected area.
4. Click and drag a box around another area.
5. Click the Zoom to Last Extent Button
6. Click the Zoom to Full Extent Button

The Toolbar: Panning

1. Click Pan on the toolbar .
2. Click the map and drag the mouse in the direction you want to pan. E.g. To see more to the left, click and drag the map to the right.
3. Release the mouse button, and the map display refreshes.

The Toolbar: Identifying Features

1. In the TOC, Click Active (the circular button) beside a layer to make it active.
2. Click Identify on the toolbar .
3. Point to a feature and click. Attribute information for the feature you clicked appears in tabular format in the panel below the map display area.

The Toolbar: Finding Features

1. Click Active beside a layer to make it active.
2. Click Find on the toolbar .
3. Type a string to search for in the Find text box.
4. Click Find String. As with the identify tool a list of features with an attribute value matching the string you typed appears in the panel below the map display area. The features are also highlighted on the map.
5. Scroll down and click Zoom to these records to zoom to all of the features returned by your search.

The Toolbar: Measuring Distances

1. Click Measure on the toolbar .
2. Click the starting point on your map.
3. Click to add a second point, creating a line segment.
4. Click to add a third point, creating a second line segment. Repeat to create additional line segments. The Total distance of all of the line segments appears in the Total text box.

The Toolbar: Changing Display Units

1. Click Set Units on the toolbar . The Set Units panel appears below the map display area.
2. In the box below the map display area, click the Display Units dropdown arrow and click Feet, Miles, Meters, or Kilometers.
3. Click Set Units.

The Toolbar: Graphical Selection by Rectangle

1. Click Active beside a layer to make it active.
2. Click Select by Rectangle on the toolbar .
3. Click and drag a rectangle onto the map. All features contained by or in contact with the rectangle are listed in the bottom panel and highlighted on the map.

The Toolbar: Graphical Selection by Line or Polygon

1. Click Active beside a layer to make it active.
2. Click Select by Line/Polygon on the toolbar .
3. Click the map to create each point in your line or polygon.
4. Click Complete Line & Select or Click Complete Polygon & Select. The final segment of a polygon is automatically added. All features contained by or in contact with the graphic are listed in the bottom panel and highlighted on the map.

Lunch

We'll re-convene at 12:30

The Toolbar: Querying

• To perform a query, we build an expression to represent the criteria for which we want to select.
• A basic query expression is comprised of a Field Name, a Comparison Operator, and a Value for which we want to search.
• The query returns a selection of features for which the expression is true.
• Multiple basic expressions can be combined using Logical Operators to create more complex expressions.

Querying: Comparison Operators

• Comparison Operators are the glue of a basic expression that results in true or false:
  • = (equal to)
  • < (less than)
  • > (greater than)
  • <= (less than or equal)
  • >= (greater than or equal)
  • LIKE - a special operator used to compare textual values
• Examples:
  • 1 = 1 is true
  • 1 < 2 is true
  • 1 > 2 is false
  • 2 <= 1 is false
  • 2 >= 1 is true
  • "apples" LIKE "oranges" is false
  • "apple*" LIKE "apples" is true

Querying: Using LIKE with the Wildcard *

• Notice the use of the asterix in the expression
  "apple*" LIKE "apples"
• * is used as a wildcard to allow variable results in our expressions.

Query Activity 1

1. Click Active beside a layer. E.g. Hydrographic Features, to make it active.
2. Click Query on the toolbar . The query panel appears below the map display area.
3. Click the Field dropdown arrow and click a field to query. E.g. To query for a drainage use Name.
4. Click the Operator dropdown arrow and click an operator. For this example, try the LIKE operator.
5. Type a value in the Value text box or click Get Samples and click one of the sample values that appear in the dropdown list. Click Add to Query String.
6. If you are done building your query, click Execute. If you are not done, continue adding to your query, then click Execute. A list of features matching your search criteria appears in the box below the map display area. The features are also highlighted on the map.
7. Scroll down and click Zoom to these records to zoom to the features returned by your search.

Querying: Using Logical Operators

• Logical Operators are used to combine or modify basic expressions
  • AND
  • OR
  • NOT
• Expressions can be grouped with parentheses ( )
• Examples:
  • (1 = 1) AND (2 = 2) is true
  • (1 = 1) AND (1 = 2) is false
  • (1 = 1) OR (1 = 2) is true
  • NOT 1 > 2 is the same as 1 <= 2

Query Activity 2

Practice building and running some compound query expressions.

The Toolbar: Buffering and Selection by Buffer

1. Click Active beside a layer to make it active.
2. Select features of the active layer using one of the selection or querying tools.
3. Click Buffer on the toolbar . The Buffer panel appears below the map display area.
4. Click the Layer dropdown arrow and click a layer.
5. Type a buffer distance in the text box.
6. If you want to see the attributes of features within the buffer, check Display Attributes.
7. Click Create Buffer. A buffer appears around the selected features. Features from the selected layer that fall within the buffer are highlighted. Attribute information about the features appears in tabular format in the bottom panel. Be cautious with the number of features you try to buffer. Depending on the number of features selected and the buffer distance, creating a buffer can take a while.

Break

We'll re-convene in 10 minutes.

Activity: Making a Map

Make and print a map.

Consider:

• What is the purpose of your map?
• Is the scale of your map appropriate (ie. are you zoomed in or out enough to display the necessary elements for your map)?
• Are there any "extra" layers turned on that might prove distracting?
• Is it possible you need more than one map?

The Toolbar: Printing

1. Click Print on the toolbar . Print options appear in the panel below the map display area.
2. Type a title for the printed map.
3. Click Create Print Page. A new browser window opens containing a printable version of your map.
4. Click File and click Print. The Print dialog box appears.
5. Check the print settings and make any necessary changes.
6. Click OK. The map prints, complete with a title, legend, overview map, scale bar, and North arrow.