Combining Regions

Michael Nealy

May 12, 2021 19:30

INTRODUCTION

Users can combine Regions using the Map or List View in IMPLAN or upload them with the Combined Region Builder template. The Map View is the easiest method when there are a few areas to combine. However, when combining multiple regions at a time, this process can be streamlined by using the Region List or Combined Region Builder template.

This article will showcase all methods of combining regions, identify features in the Region List View, and show ways to access previously Combined Regions.

COMBINING REGIONS FROM THE REGIONS MAP

Users can create a custom Combined Region in IMPLAN with just a few simple clicks. Note, that only countries, states, provinces/territories, and counties can be combined from the Map View; zip codes must be combined using the Region List View.

From the Map View on the Regions screen, select all of the Regions by clicking them from the map. Click More Options in the Selected Regions panel, then click Combine Regions.

A popup will appear asking to name the new Combined Region. Remember to give it a unique name, as this will now be saved to the user’s account and become searchable from the Regions and Impacts screens. The name can be changed later.

The spinning wheel icon will appear as IMPLAN builds the Combined Region. Once complete, the View Region Details button will appear.

The user can now proceed with the analysis by clicking Create Impact in the bottom right corner of the screen or click Save to add the Combined Region to a Project.

COMBINING FROM REGIONS LIST

The Regions List view in IMPLAN makes combining Regions a breeze! Access the Regions List view from the Regions screen by clicking List View, the second icon next to the Selected Regions panel. There are three views Users can toggle between by using the highlighted icons; the Map View, List View, and Combined & Customized View. Once a Data Year has been selected, it will remain active in all views until changed by the user.

The default setting on the List View allows users to add single Regions to their project by selecting them individually or using the Add All button. Use the arrows to expand Regions to smaller geographical units or use the dropdown menu to change those units from county to congressional districts or MSAs.

To Combine Regions from the List view, toggle on the Multi Select View option using the slider.

Once enabled, Regions will now display a checkbox next to the name to indicate their selection. Use the arrows to expand Regions to smaller geographical units, such as county and zip codes.

For example, to see all of the Counties in Alabama, click the arrow to expand the selection. This will list all 67 counties in Alabama.

If we wanted to see the zip codes for a certain county, say Bibb County Alabama, click the arrow to expand the selection. This will list all 8 zip codes in Bibb County:

Users may combine any state, county, or zip code together as long as the selected regions do not overlap. For example, the state of North Carolina may be combined with a county in South Carolina, but can not be combined to a county within North Carolina.

Click the checkbox next to the Regions that need to be combined and select Combine Regions at the bottom right of the screen. In this example, we are going to set up a Multi-Regional Input-Output (MRIO) analysis creating a combined region of all counties in Alabama, except Baldwin.

Doing this will prompt the user to name the Combined Region. Make sure to choose a unique name that is easy to remember as Combined Regions are saved to the account and searchable from the Regions or Impacts screen. The name can be changed later.

Once combined the new Region will appear in the Selected Regions panel on the right. From here users can explore the Region Details of the Combined Region, create additional Combined Regions, or add single Regions.

To add single Regions from the Multi Select View, select Regions using the checkbox, but use the dropdown menu to change from Combine Region to Add Region or Build Region. Selecting Build Region will add the selected Regions and also automatically build them. This can be a huge timesaver if there are many Regions to select in a Data Year that has not been used previously.

As this example shows, the user added Baldwin County to set up their MRIO.

After the Regions have been combined and/or selected, click Save to save them to the project or Create Impact to advance to the Impacts screen to add Events.

COMBINED REGION BUILDER TEMPLATE

Users can upload Combined Regions to the Regions page using the Combined Region Builder template. This template allows users to create a Combined Region using any combination of U.S. zip codes or county and state level FIPS codes. At this time, the Combined Region Build template is only applicable to the U.S. data set.

The template is a very specific file, and each field must be filled out as it is shown in the original template. If IMPLAN detects any errors in the uploaded template, it will display an appropriate warning message on the Import Combined Region window indicating whether a specific Region can be imported without modifications.

Follow the directions contained within the Combined Region Builder template. Each Combined Region must contain the following:

Region Name: This field is required. Enter a unique name for each Combined Region. Combined Regions must not contain any overlapping geographies in the same Data Year.

Data Year: This field is required. This field indicates the Data Year for the Combined Region. The template will fail to upload if left blank.

FIPS Code: This field is optional.* Enter a 5-digit FIPS code for each Group in the project. All FIPS codes must contain 5 digits, therefore these values must be formatted as text. Any state FIPS code must include three trailing zeros. For example, the Alabama FIPS code must be entered as 01000.

Zip Code: This field is optional.* Enter a 5-digit zip code for each Group in the project. All zip codes must contain 5 digits, therefore these values must be formatted as text.

*While each of these fields is optional, one of them will require an entered value. The template will fail to upload if both fields are populated in a single row.

UPLOADING THE COMBINED REGION BUILDER

To upload Combined Regions using the template, click on the More Options icon from the Selected Region panel. Click on Import Combined Regions.

Click on Choose file to locate from your computer or drag and drop the file into the import area, then click Upload.

Check the box of each Combined Region, then click Import.

ACCESSING COMBINED REGIONS

Now that the Regions are Combined, they will show up in the Combined & Customized View and will be accessible for future use in any project. Users can add them to any project from the Combined & Customized View by clicking on the Add icon. From here users can also delete or rename any of the Combined Regions.

In addition to the Combined & Customized View, any previously Combined Regions can be found by using the search bar near the top left of the Regions screen or in the Group Region dropdown on the Impacts page.

NOTE OF CAUTION

Combined Regions can be built using country, state, county, zip code, congressional district, or metropolitan statistical area (MSA) Regions. This also includes US Territories, which can be Combined with other mainland U.S. Regions. Note that users cannot combine a previously Combined Region or Customized Regions. Users are free to combine any non-overlapping Regions from the list. The following warning will appear when it is attempted to select a Region that is contained in another selected Region:

We received this error message because we attempted to Combine Fresno County with one of its parent Regions, the state of California. No matter which approach we take to combine Regions, this will never work as it would count Fresno County twice.

Also, at this time the Region list is limited to selecting 500 Regions to combine at once. At the bottom right of the screen, a running total of all the Regions that have been selected is displayed. When the limit of 500 has been exceeded, a warning will appear and the Combine Regions button will be grayed out as unavailable.