Global Mapper Pro

Сrop area along line

Sorry for Google Translater!
I have an area and a line that crosses it. How can I divide the original area into 2 parts along this line?
In the archive - .shp,, prj ... e.c.t


  • In the archive - .shp,, prj ... e.c.t 2.7K
  • Hi Petr,

    Easiest way to do it is in AutoCAD by trimming area to line first on left hand side (LHS) and then on right hand side (RHS). However can be done in GM as follows (refer to attached zipped PowerPoint slides):

    1. Select area and zoom in as far as possible (sub-1m) and, by eye,  Add Vertex at top and bottom points where line crosses - this won't be millimetre perfect but hopefully close enough given size of area (>3,500 km2).
    2. While selecting area, convert area to lines by Create Line(s) from Area.
    3. Select vertices (from Step 1) and "cut" outer lines top and bottom - this will create a LHS and RHS side. Cut and paste LHS to a new layer called LHS and RHS to a new layer called RHS.
    4. Display LHS only and draw line from vertex to vertex (make sure Snapping option is turned on).
    5. Select LHS lines, including the one drawn in Step 4, and then Create Area(s) from Line(s).
    6. Modify allowable distance if necessary, but if snapping is on then there should be 0m distance. You will now have a LHS area.
    7. Repeat for RHS and you will now have divided your area in two!

    As I say, much easier in AutoCAD, but doable in GM if you have no option.


  • geomannie
    geomannie Global Mapper User Trusted User
    It's actually very easy in GM. Select both items with the digitiser tool, rightclick and select the correct options. See image

  • Thanks Geomannie. They say it's a sad day when you don't learn something new!


  • Many thanks to all who responded!
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