Demand-Based Site Selection for Fire Stations Using a Network Allocation Model

Table of Contents

  1. Demand-Based Site Selection for Fire Stations Using a Network Allocation Model
  2. Setting up Your Workspace
  3. Preparing the Data
  4. Skill Drill: Clip the Roads Layer to the City of Arcata and McKinleyville
  5. Skill Drill: Add a Time Cost Attribute to the Roads Layer
  6. Skill Drill: Creating a CSV Table to Import As XY Data
  7. Skill Drill: Geocoding an Address  and Creating a CSV Table to Import As XY Data
  8. Skill Drill: Adding the Fire Incident History as XY Data
  9. Creating A Network Dataset
  10. Setting up a Network Allocation Model
  11. Loading Facilities into the Model
  12. Loading the Demand Points into the Model
  13. Adjusting the Analysis Setting of the Model
  14. Running the Network Allocation Model
  15. Skill Drill: Using the Maximize Attendance Problem Type
  16. Skill Drill: Adding Existing Fire Stations to the Model
  17. Skill Drill: Creating a Map of the Results

Skill Drill: Creating a CSV Table to Import As XY Data

In this scenario, several sites were proposed as potential replacement locations for the new fire stations. These locations must be evaluated to determine the top three choices for the Arcata Fire Protection District and related regions. In Microsoft Excel, create a CSV table with the following field headers: name, latitude, longitude. Enter the name, latitude, and longitude values show above in the appropriate fields. Save as a CSV table and close Excel.

Sunset Fire Station40.879955-124.085222
Samoa Fire Station40.865417-124.089811
Bayside Fire Station40.857932-124.072109
Community Park Fire Station40.86473-124.079219
Alliance Fire Station40.874875-124.090217
Janes Fire Station40.901818-124.091445
Giuntoli Fire Station40.904993-124.078412
West End Fire Station40.903426-124.071856
Central Fire Station40.930078-124.101093
Hiller Fire Station40.942134-124.105222
Railroad Fire Station40.945557-124.105554
Pickett Fire Station40.944498-124.097953
Grange Fire Station40.977792-124.100109
Murray Fire Station40.956121-124.095253
Fickle Hill Fire Station40.867667-124.073769

A GPS receiver set to WGS 1984 was used to obtain the geographic coordinates in decimal degrees. It’s important to remember that each geodetic datum as a unique set of latitude and longitude values. For example, the latitude and longitude values for your home using the North American Datum of 1983 will be different than the latitude and longitude values using the North American Datum of 1927. Likewise, the World Geodetic Datum of 1984 (WGS 1984) will use yet another set of latitude and longitude values to define the location of your home.

Like most latitude and longitude values, you will obtain from the internet or from a GPS receiver, the decimal degrees in this are currently in the geographic spatial reference system WGS 1984. When adding XY data, the ArcGIS software only reads the decimal degrees. It is unaware to which spatial reference system these decimal degree values belong. ArcMap will assume, incorrectly, that the spatial reference is the same as the dataframe. You must indicate in the Add XY data dialog box that this series of decimal degree values belong to the WGS 1984 spatial reference system. If you do not, your proposed sites will likely end up somewhere in the ocean.

An image of the Add XY Data dialog box
You can locate the spatial reference ArcMap will use under the Description. To re-define the spatial reference, click on the Edit button to select the correct spatial reference.

After adding XY data, the ArcGIS software will create a temporary events layer. In many ways, the events layer appears to be similar to a shapefile. However, it is only a temporary representation and does not have an associated database.

An image of the Warning Dialog Box in ArcMap.
The ArcGIS software will remind you that you will still need to export the events layer in order to create a permanent shapefile that includes database functionality.

Export the events layer as a shapefile and save it to your working folder. You should now have a shapefile of the proposed locations in the WGS 1984 spatial reference system saved in your working folder. Next use the Project tool to create a copy of the data with the NAD 83 UTM Zone 10 spatial reference system. Add the layer with the correct spatial reference to your Table of Contents and remove the old version.

An image of the proposed location events layer.
An events layer is temporary and should be exported as a shapefile.