Grid Volume

Use the Grid and Image > Utilities > Grid Volume menu option (GRIDVOL GX) to calculate the volume of space defined by a grid surface, above and below a base of reference.

Grid Volume dialog options

Grid file	Select the name of the input grid file (*.grd). Script Parameter: GRIDVOL.GRD
Reference base for volume calculation	Reference base from which to calculate the volume (Default is 0). Script Parameter: GRIDVOL.REFBASE
Multiplier to apply to volumes	Multiplier to apply to the final volume, to correct for units (Default is 1). Script Parameter: GRIDVOL.MULT

Volume Report dialog options

Volume above reference base	Volume of grid above REFBASE (Output!) Script Parameter: GRIDVOL.ABOVE
Volume below reference base	Volume of grid below REFBASE (Output!) Script Parameter: GRIDVOL.BELOW
Difference	Difference between volumes (Output!) Script Parameter: GRIDVOL.DIFF

Application Notes

GRIDVOL.ABOVE, GRIDVOL.BELOW, and GRIDVOL.DIFF are output values only. GRIDVOL.ABOVE and GRIDVOL.BELOW are reported as positive values.

GRIDVOL can be useful for determining the volume of material defined by grid surfaces in topographic applications. Some geophysical applications also make use of volumes under anomalies to derive physical properties (e.g. gravity).

The volume of the grid is simply displayed on the default output as a floating point number. This output can be piped to another application if desired. The volume is calculated by summing the product of the grid cell area times each non-dummy grid point.