Shadow range is the volume of energy, the number of people, the planetary surface, the various elements that tell you how big the shadow is.
For instance a volcanic eruption in Iceland that disrupts air traffic all over Europe is a range of 50%.
A whole continent is touched.
The intensity is relatively low, maybe 20%, because no one gets killed. The shadow is manageable and lasts for a month or two.
The tsunami in Asia some years ago?
Same kind of range at 50% on a whole continent but super high intensity at 100%, and very short duration.
If you include the after effects, the duration is much longer and stretches to years.
So now we have:
Three parameters that define a shadow's impact.