Spatial Aggregation

Introduction

The Spatial Aggregation tool allows you to take the small area population projection data and aggregate spatial units together and sum the projections over those selected areas. For example, we may want to combine the population projections for a number of SLAs or LGAs.

Inputs

To illustrate the Spatial Aggregation tool in use, we will sum some SLA population projections across the LGA of Moreland in Melbourne. To do this:

  • Select Moreland (C) LGA as your area
  • Select SLA Small Area Population Projections 2006-2031 for Australia as your dataset, selecting all attributes and 2031 as your projection year.

Once you have done this, open the Spatial Aggregation tool (Tools → Specialist Tools  → Spatial Aggregation) and enter the parameters as shown below. These are also explained below the image.

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  • Dataset input: The Small Area Population Projection (SAPP) dataset required to run the tool. In this instance, we select the dataset we loaded called SLA Small Area Population Projections 2006-2031 for Australia
  • SLA or LGA data: We select whether our input dataset is at LGA or SLA level. In this instance we select SLA
  • Projection Target Year: We select which year’s population projection we pulled in. In this instance, we select 2031
  • Regions to be aggregated dataset: We are required to re-enter the dataset we’re using to run the tool, in this instance  SLA Small Area Population Projections 2006-2031 for Australia
  • Regions to be aggregated attribute: This is where specify the column that we’ll use to identify the regions we want to aggregate. In this instance, we select SLA_Name
  • Regions to be aggregated values: This is where we select the individual records that we want to include in our aggregation. For this example, we select Moreland (C) – Brunswick, Moreland (C) – Coburg, Moreland (C) – North

Once you have entered the parameters, click Add and Run to execute the tool.

Outputs

Once you have run the tool, click the Display button on the pop up dialogue box that appears on your screen. This will open a table like the front table in the image below. If you compare this output to the original table (rear table in the image below) you will see that the areas have been summed for all of the population projections across the three SLAs

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