To not waste any time, this is NOT a tool that is designed for permaculture analysis.
This IS a tool that most everyone online has used.
If you're a Google Earth veteran, you'll like where this tutorial goes.
I use Google Earth for permaculture analysis.
Interested in keyline irrigation, I had to evaluate the contour.
It was easy to see the rough contour of the land, but not much more.
After drawing a polygon to outline the boundaries of the land, I realized that I could do more.
I created multiple layers with different colors at set intervals to create colored contour on the land.
View of my land in Google Earth 3d terrain with my contour layers overlayed.
Allowing me to look at the higher elevations of my land separately
With these layers each set at 5 meters
You even get a good view of the watershed area above the land.
Turning the camera around about 180 degrees, a view from the high watershed to the low area
These allow me to plan things in order of permanence.
First, I must look at where I can hold water at high elevation,
and where the roads will be along the ridgelines.
In my case, I choose to preserve the south and easterly views,
and keep the road traveling up the western ridges.
I hope that this helps everyone.
I do have a screen recording of the process in creating these contours.
The audio is bad, so I did not upload it.
Let me know if you would like to see the video posted, also.