Could anyone tell me a way of getting my polylines to search for a point within a certain number of meters of their start/end points and extend to it?

There was some problem uploading a picture so I'll explain further. I have contours with gaps like here and am able to close them, but have found that other gaps, caused by edges to the area and faults are also being filled, the lines also travel completely straight when this is not quite the case. I also have a point feature class of where annotations used to be. The gives one more point when the gap should be slightly curved, and identifies the gaps that I actually want to fill. So I want to do something similar to closeing rings, but instead of extending the lines to meet eachother I want to extend them to meet the point.

  • In other words, you want to close rings, right?
    – julien
    Commented Dec 10, 2013 at 13:04
  • 1
    A screenshot might clarify things.
    – Martin
    Commented Dec 10, 2013 at 13:18
  • @julien No, I've managed to close rings but i want to connect to a midway point to stop if from closing ring that are supposed to be there. Commented Dec 10, 2013 at 13:26
  • @Martin I'll add a screenshot Commented Dec 10, 2013 at 13:26

2 Answers 2


for full control on extending lines, another possibility (besides the topology tools) is to create the line segments that fill the gaps and merge them with your lines based on some common attributes (using dissolve). So:

1) create the end points of the lines (feature vertices to point)

2) get the closest point (spatial join)

3) create the line segment (XY to line)

once you've done this, you can check that both end points of your segment have the same height, copy this height in a new field, merge with your contour lines and dissolve based on the height field.


Simply rebuild the surface and contours from the existing contour lines.

  • (+1) This is probably the best approach but a whole world of finicky details is lurking beneath that introductory adverb "simply"! One would hope, though, that many of those details can be overlooked because when the gaps are small, even a quick and dirty reconstruction of a DEM might do a good job.
    – whuber
    Commented Dec 13, 2013 at 16:10

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