Create a New Redistricting Plan¶
Note
Before you can create a plan, you must create a QGIS project that includes the layer or layers containing the geographic units and demographic data from which your redistricting plan will be built.
The "Create New Plan" dialog¶
When New Redistricting Plan is selected from the QGIS redistricting plugin toolbar or menu, the “Create New Plan” dialog guides you through creating a redistricting plan.
Page 1 - Plan Details¶
The first page of the “Create New Plan” dialog allows you to select a name for your plan, provide the path to a new GeoPackage file that will contain your plan layers, and specify the number of districts in your plan and the number of members who will represent those districts. You may also provide an optional description. The following constraints apply.
The plan name must be unique among redistricting plans for your project
There must be two or more districts in your plan
The number of members must be equal to or greater than the number
Page 2 - Geography¶
The second page of the “Create New Plan” dialog allows you to define the geography from which your plan will be built.
Import Geography from Layer - Specify the layer containing the smallest units of
geography you will use to create your plan (e.g., census blocks).
Primary Geography ID Field - Specify the layer attribute that uniquely identifies
the geographic units. This field will be used to join the layer containing the demographic
data (if it is different from the geography layer).
Geography Name - You may also provide a more descriptive label for your geographic units here.
Additional Geography - Here, you may define additional units of geography that may be used
to build your districts. Geography is defined using fields from the primary geography layer.
For example, if your primary layer is U.S. Census Bureau census blocks, and each block contains
an identifier for the county or census tract in which it falls, you can add that field to the
list of additional geography to allow building districts from counties or census tracts. You may
define additional geography using individual attriabutes or QGIS expressions. Once the
addtional unit is added, a more descriptive caption or label can be provided.
Page 3 - Population¶
The third page of the “Create New Plan” dialog allows you to specify the layer containing the population data your plan will use.
Population Layer - If your population data is contained in a separate layer from
your geographical building blocks, specify the population layer here. Population data
must be provided at the same level of geography as the geographic units. If not using a
separate population layer, specify “Use the geography layer” here.
Join Field - If using a separate population layer from the geography layer,
specify the field in the population layer that will be used to join the population
data to the geographic units. This field must contain the same geographic identifier
as the Geo ID Field used to uniquely identify the geography.
Total Population Field - Specify the name of the attribute containing the total
population for each geographic unit.
Maximum Deviation - Specify the maximum population deviation above or below the
ideal population for each district that is permitted for your plan.
Voting Age Population Field - Optionally specify a field containing the total
voting age population for each geographic unit.
Citizen VAP Field - Optionally specify a field containing the total
citizen voting age population for each geographic unit.
Page 4 - Additional Demographic Data¶
The fourth page of the “Create New Plan” dialog allows you to specify additiolnal demographic data that will be tracked for each district in your plan.
Demographic data is defined using fields from the population layer. You may define demographic using individual attributes from the population layer or QGIS expressions. Once the addtional demographic data field is added, a more descriptive caption or label can be provided, and you can specify whether to track the total population for the demographic group and/or the population of the deographic group as a percentage of total population, voting age population, or citizen voting age population.
Page 5 - Import Assignments¶
The fifth and final page of the “Create New Plan” dialog allows you to optional import district assignments for your plan from a CSV or Microsoft Excel file. You may also import assignments at a later point using the “Import Assignments” option available on the QGIS redistricting plugin menu.
