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Working with Polygon Analysis
Working with Polygon Analysis

How to work with polygon analysis and how calculations are made

Written by Emil Hansen
Updated over a week ago

Polygon analysis allows you to get metrics on how a chosen polygon (corridor, substation etc) overlaps with geodata, both directly and in its proximity.

Polygon analysis can be found in two places

  1. In the polygons table, available on the "DATA" page

2. In the point information tool

What to expect from the calculations

For each chosen buffer, two values are calculated:

  1. The overlap between the polygon and the selected layer(s)

    1. Units are provided in square kilometres.

  2. The number of features in the selected layer(s) that intersect the polygon

Feature intersection counts

The analysis counts the number of features that are touched by the polygon and its buffers. Each feature is only counted once if intersected by the same polygon.

For example, the following intersection will count as one even though the polygon intersects the dataset feature multiple times

Area of Intersection

Intersection area (in square kilometres) is calculated to be the sum of overlapping area of the polygon and each feature in the the selected layer.

This is important to note when working with buffered layers where features often overlap:

In the image above, the top polygon is overlapping more building buffers and counts an overlapping area much larger than the polygon below even though they are both the same size.

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