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Chapter 6 Using GIS for Spatial Analysis
Dakota and the locations of some cities and roads in the area, and then switches to the Great Lakes region in Section 6.6. With the sample data covering
the state boundaries and city locations for the whole United States, it’s easy
enough to select your city (or ones nearby), as well as major roads or lakes
and perform the same measurements and analysis using those places more
local to you than ones in these areas.
6.1 Some Initial Pre-Analysis Steps
1. Start ArcMap.
2. From the USA folder, add the following shapefiles: states, cities, lakes,
rivers, and intrstat.
3. Change the color schemes and symbology of each layer to make them
distinctive from each other for when you’ll be doing analysis. (See
Lab 5.2 on page 130 for how to do this.)
4. Position the layers in the Table of Contents (TOC) so that all layers are
visible (that is, the states layer is at the bottom of the TOC and the other
layers are arranged on top of it).
5. When the layers are set how you’d like them, zoom in to South Dakota,
so the state (and the nearby data) fills up the screen.
6.2 Database Queries
1. A database query is a standard feature in ArcMap. We’ll start off
with a simple query (using only one expression). To build a query
in ArcMap, choose Select by Attributes from the Selection pull-down
menu.
2. The Select by Attributes dialog box will appear.
3. You’ll be building a simple query to find which points (representing
cities) are in South Dakota (SD).
4. To build a query, first select the Layer to use. In this case, choose cities
(since it’s the layer that we will be querying).
5. Next, select the Field to query. In this case, choose “ST” by doubleclicking it with the mouse.
6. Next, select an operator to use. In this case, select the = operator,
clicking on the symbol with the mouse.
7. Lastly, select the appropriate values. Press the Get Unique Values
button to get a list of all the possible values associated with the “ST”
Field. In this case, choose ‘SD’.
8. The query will appear in the dialog box (“ST” = ‘SD’). This will select all
records whose ST field is equal to the characters ‘SD’.
9. Click OK to run the query.
Chapter 6 Using GIS for Spatial Analysis
Dakota and the locations of some cities and roads in the area, and then switches to the Great Lakes region in Section 6.6. With the sample data covering
the state boundaries and city locations for the whole United States, it’s easy
enough to select your city (or ones nearby), as well as major roads or lakes
and perform the same measurements and analysis using those places more
local to you than ones in these areas.
6.1 Some Initial Pre-Analysis Steps
1. Start ArcMap.
2. From the USA folder, add the following shapefiles: states, cities, lakes,
rivers, and intrstat.
3. Change the color schemes and symbology of each layer to make them
distinctive from each other for when you’ll be doing analysis. (See
Lab 5.2 on page 130 for how to do this.)
4. Position the layers in the Table of Contents (TOC) so that all layers are
visible (that is, the states layer is at the bottom of the TOC and the other
layers are arranged on top of it).
5. When the layers are set how you’d like them, zoom in to South Dakota,
so the state (and the nearby data) fills up the screen.
6.2 Database Queries
1. A database query is a standard feature in ArcMap. We’ll start off
with a simple query (using only one expression). To build a query
in ArcMap, choose Select by Attributes from the Selection pull-down
menu.
2. The Select by Attributes dialog box will appear.
3. You’ll be building a simple query to find which points (representing
cities) are in South Dakota (SD).
4. To build a query, first select the Layer to use. In this case, choose cities
(since it’s the layer that we will be querying).
5. Next, select the Field to query. In this case, choose “ST” by doubleclicking it with the mouse.
6. Next, select an operator to use. In this case, select the = operator,
clicking on the symbol with the mouse.
7. Lastly, select the appropriate values. Press the Get Unique Values
button to get a list of all the possible values associated with the “ST”
Field. In this case, choose ‘SD’.
8. The query will appear in the dialog box (“ST” = ‘SD’). This will select all
records whose ST field is equal to the characters ‘SD’.
9. Click OK to run the query.