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Image 1 shows before editing. Image 2 shows 'edited line which i used too split with and with labels Close up in 3rd image.

I often split polygons with a line (ArcGIS 10.1 Split Polygon tool). In this case, and as an example: The polygons' boundary is coincident with a line (river); and opposite sides of the line/river. I re - digitise (to improve accuracy) the river and smooth the line. I then use this line to split the adjacent polygons. Often MANY small polygons (100+) are created and these are extremely cumbersome to manually integrate with the correct 'big polygon' they should be merged with. They are so small that it is by labeling them, they can be seen easily.

I usually seect them mannually and merge them with the correct polygon.

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    Have you considered the Integrate tool in conjunction with merge/dissolve? – Barbarossa May 31 '14 at 15:32
  • Thx, have not tried before and although it seems the tool to use the results were very 'inconsistent when i tried it know. – Johan Baard May 31 '14 at 16:44
  • Can you provide before/after images of what you are trying to accomplish? – Barbarossa May 31 '14 at 16:50
  • Thx, i can. My first time here, how do i attach images? – Johan Baard May 31 '14 at 17:11
  • Edit your question, and above where you input text, there is an IMAGE button. – Barbarossa May 31 '14 at 17:59
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Split is the wrong approach for this sort of thing, for just the reason you have found (all those slivers). There are several ways to approach the problem. You might want to take a look at the help files on common editing tasks such as this one to get some ideas of different tools and methods available.

One, and probably the best for a single-pass operation, is to use topological editing. In this way you can reshape all three boundaries (the river and both adjoining polylines) in a single edit operation. Map topologies are supported even at the Basic level, but Standard and Advanced offer even more functionality.

Another approach is to reshape (different) (or redraw as you are doing) your river, then reshape the adjoining polygon edges using one of several methods. The Trace tool works; or you could reshape the polygon and not pay attention to the river beyond making a quick two or three vertex edit that makes sure the entire boundary goes past the river, use the split then, and delete your two extra polygons (possibly Clip with no delete required - I haven't done this type of digitizing in a while). You can also use Replace Sketch while editing the polygon with the river line selected.

One tip I would give for many of these methods is to do sections at a time rather than try to do an entire edit at once. The longer you're in an edit command, the more effort you stand to lose if something goes wrong.

  • Thx, much appreciated. I tested the 'reshape' and that will help me in many cases. – Johan Baard Jun 1 '14 at 8:59
  • I tested the 'reshape' and that will help me in many cases. I also often use a GPS track (or a redigitised line) for the split. This line is then smoothed before doing the split which give a neat smooth line, which i like. This of course results in the numerous slivers. A way i tested and works, is to (i will describe as if it is 2 polygons): select all the parts of one of the original two polys, then deselect the large original of these, manually select the large one (adjacent) with which it have to integrate and merge from Editor Toolbar. Bit boring but works. – Johan Baard Jun 1 '14 at 9:07

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