Global Mapper v25.0

Calculate Volumes - Area or multiple surfaces?

kfroese
kfroese Geotechnical EngineerTrusted User
edited September 2011 in Elevation Data
I am trying to calculate the volume of fill required to construct a berm on the side of an existing hill. I have topo data for the existing ground and the desired elevations of the berm. I have tried several ways to get the volume that will be necessary but haven't had success.
-I created a surface of the berm and checked out combining surfaces against the original ground topo but that only gets the amount of fill required at each point on the DEM. I really need a volume comparison between my surfaces.
-I created areas of the upper and face surfaces of the berm and tried to use Volume Calculation but that only got me volume as reference to sea level which is a bit more fill than I think I'll need.
-I tried creating a line to represent the perimeter of the berm but in Volume Calculation I was only able to sample along the line at some buffer distance.

Am I missing something?

Thanks in advance.

Comments

  • global_mapper
    global_mapper Administrator
    edited September 2011
    I think what you will want to do is use the File->Combine Terrain menu command to create a new terrain surface that is the difference between your surface with the berm and the one without. Then close the other surfaces and calculate the fill volume against the difference surface.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
  • kfroese
    kfroese Geotechnical Engineer Trusted User
    edited September 2011
    You are right: that is what I needed.

    Can I put forward a suggestion on this topic? The current method, which works, does involve extra steps in that a surface has to be generated, then the surfaces can be subtracted, then the volume can be calculated from an area. Any chance of getting volume calculation between two surfaces directly? Or between an area feature (with elevations on the vertices of course) and a surface?

    Thanks for your help.
  • global_mapper
    global_mapper Administrator
    edited September 2011
    This does come up on occasion, I will add an item to the todo list to make this easier.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com