# Cut and fill volumes

Mark Gale
Global Mapper UserPosts:

**36**Trusted User
Hi,

I'm using the measure tool to calculate cut and fill volumes for an area of complex shape (i.e. several hundred mouse clicks to define the shape). How do I save the area to allow me to reselect it for future re-measurements of the changing cut and fill volumes without having to retrace the area each time?

Thanks.

I'm using the measure tool to calculate cut and fill volumes for an area of complex shape (i.e. several hundred mouse clicks to define the shape). How do I save the area to allow me to reselect it for future re-measurements of the changing cut and fill volumes without having to retrace the area each time?

Thanks.

## Comments

12Trusted UserJust use the "Create Area Feature" to make the shape you need (instead of using the Measure Tool), save the shape to whatever format you prefer.

When you need to perform the calculation, select the shape using the Digitizer Tool, right-click, select Analysis/Measurement and then select the appropriate calculation method.

Hope that is what you are after.

cheers, Andy

36Trusted User12Trusted UserWhen you bring up the "Volume Calculation Parameters Setup" menu, are you choosing the same option under "Volume Calculation Type" for both methods, i.e. "Calculate Cut-and-Fill Volumes within Area Feature"?

I've done some quick tests on one of my elevation sets and am getting the same volumes for both methods, so not 100% sure what is happening in your case.

cheers

36Trusted User36Trusted User12Trusted UserOtherwise (maybe) there is something going on with your complex shape such that GM is calculating things differently between methods ... will have to leave that one to the GM experts. cheers

12Trusted User36Trusted User36Trusted User36Trusted User36Trusted User58Trusted User- David McKittrickSenior Applications SpecialistBlue Marble Geographics

36Trusted UserIthink I have two issues here:

1. IfI take two surfaces, use "Combine/Compare Terrain Layers", then do a"Volume Calc", "Calculate Cut & Fill, "Use Same BaseHeight value for all Vertices" (0) using the Combined Elevation Grid, Iget a different value to a simple "Analysis", Measure Volume betweenSurfaces" using the original two surfaces (in the latest case, 265.59499cu m. to 257.65 cu m.)

2. Difference in results between using the Measure Tool and Digitizer: granted, some of the vertices may be very slightly different, but having checked a number of times, the volumes still come out significantly more different than this could account for.

Cheers.

435Trusted User(assuming three equal and perpendicular sides).

If you measure the side of a cube, you can probably get closer than that.

Your volume appears to NOT be a regular shape, so I wonder how precisely you can define the volume.

It doesn't take much of a bobble to significantly affect the results.

I'm saying that without knowing how Global Mapper calculates volumes.

This is an interesting discussion, since others have had issues in the past (with larger volumes).

58Trusted UserTo calculate the volume between two surfaces within the bounds of a specified area, use the Analysis > Measure Volume Between Surfaces function. This is a single calculation that will result in a more precise volumetric measurement. The alternative workflow that you followed is a two-stage calculation (Combine/Compare Terrain Layers function to create a third surface model followed by a calculation of the volume between this surface and base elevation of zero). Each of the two steps will inevitably result in a certain amount of rounding or interpolation which will cause the calculated values to be slightly different.

- David McKittrickSenior Applications SpecialistBlue Marble Geographics

36Trusted User11ich habe einen Berg wo eine ebene Strasse durchlaufen soll.

Wie kann ich das visualisieren