The Depth Index is the average Euclidean distance from the polygon's interior points to the nearest perimeter point. The index is normalized using the Equal Area Circle (EAC) as follows...

The Depth Index is appropriate to use when...

- an indicater of the polygon's exposure to external conditions is needed - greater depth indicates greater insulation from outside influences.
- the width of the edge disturbance zone is not known
- a measure of compactness is needed

Depth Index results for select shapes...