Global Mapper v25.0

Create Area Features from Existing Line and Area Features

rreed
rreed Global Mapper UserTrusted User
edited December 2014 in Technical Support
Hello,

I've delineated a drainage basin from a topo map using the Create Area Features Tool, and now I want to delineate sub basins and/or adjacent basins. Rather than re-digitizing common boundaries, I want to use the Line Feature tool to draw lines that terminate at the existing area feature and then have GM create a new area feature that is bounded by the existing area feature and the line(s).

I know this must be simple, but I've read the help and many of the threads - this doesn't seem to be addressed anywhere.

Thanks.

Russ

Comments

  • rreed
    rreed Global Mapper User Trusted User
    edited December 2014
    For anyone else who may have this same question, I've figured out a way to do this - it may not be the most efficient way, but it works.

    Once you have an area feature drawn, draw the line feature representing the adjacent area, making sure that both of the end points of the new line feature cross into the area feature. Next, select the line and then create an area feature from the line (Advanced Feature Creation Options -> Create Area From Selected Line). This function will connect the two endpoints of the line with a straight line and create the corresponding area (make sure the straight line connection doesn't go outside of the original area feature). Next, select the original area feature and clip the original area from the new area feature (crop/combine/split functions -> Cut Selected Area From Another Area), and say "no" to deleting the feature. As a last step, you'll probably want to delete the line feature that was used to create the new area feature.

    I would think there is an easier/more efficient way than this, but this the way I've found to make it work.

    Russ