Volume Between Surfaces command allows the user to calculate the volume
between 2 terrain surfaces. When selected, the command displays a dialog
allowing you to select the 2 layers to calculate the volume between as
well as the region within which to do the volume calculation.
Both the Measure Volume Between Surfaces and the Pile Volume volumetric calculations work by dividing the area of interest up in to small rectangular pieces, and then calculating the sum volume of the small 3D rectangles between the two terrain models or the terrain model and the cut surface (Pile Volumes).
Pile Volume(s) will calculate the volume within a defined area relative to how the all of the vertices of a selected area feature meet the terrain surface or elevation model. Vertices that do not meet the terrain surface are omitted from the calculation.
To use the Pile Volume measurement tool, you will need an area feature that encompasses the hill or pile you would like to measure the volume of, or you will need to digitize a new area feature around the pile. If the area feature does not contain elevation values for the vertices, you will need to add these. For a more accurate measurement, make sure the area feature encloses the pile or hill, without having a lot of space around the perimeter.