topic Re: line to polygon in Geoprocessing Questions

line to polygon

JayKappy — Thu, 09 Jan 2014 12:29:41 GMT

question: I have a line file that dissects a polygon. This polygon is varying distance away from the line feature that runs down the middle. Think stream center line line and polygon stream boundary.
to Complicate this the line feature is broken up into small segments where as the polygon is not as detailed.

What I am trying to accomplish here is do a buffer of a specific location.

If I use the center line if may not find the location, as its not truly representing the width of the stream.

If I use the polygon I don't get the information from the line.

If I buffer to find the polygon, then spatial query to get the line in the polygon I will be grabbing more lines due to the size of the polygons (I could inadvertently grab a stream segment 1/2 mile down stream), I would then have to do another query to find the lines in an optimal location in regards to the original buffer.

I think it might be wise to do some up-front development on the layers themselves to make things easier in the long run.

What I was thinking of is trying to offset the line (left and right) to the polygons border. I cant simply buffer the line feature because I need to to represent the boundary of the stream, as this width varies.

Or some way of buffering the line feature (creating a polygon feature) not by a specified width but until it hits the polygon border...is this possible?

Or Merger the Polygon into one, then break the polygon based on the length of the line segments. I can then do a simply spatial query to get the data from the line to the polygon.

Any other thoughts on 1-3 above? Is number 3 possible? Getting the data into a format we can use...data from the line a newly created polygon (based on original poly boundaries)

Re: line to polygon

RobertBorchert — Thu, 09 Jan 2014 12:50:23 GMT

Copy the attributes from the line to the polygon.

In an edit session in the attributes window right click the stream and select copy attributes. right click on the polygon in the attributes window and paste attributes.

As as previously mentioned if all the polyline segments contain the same data then you can merge them together.

question: I have a line file that dissects a polygon. This polygon is varying distance away from the line feature that runs down the middle. Think stream center line line and polygon stream boundary.
to Complicate this the line feature is broken up into small segments where as the polygon is not as detailed.

What I am trying to accomplish here is do a buffer of a specific location.

If I use the center line if may not find the location, as its not truly representing the width of the stream.

If I use the polygon I don't get the information from the line.

If I buffer to find the polygon, then spatial query to get the line in the polygon I will be grabbing more lines due to the size of the polygons (I could inadvertently grab a stream segment 1/2 mile down stream), I would then have to do another query to find the lines in an optimal location in regards to the original buffer.

I think it might be wise to do some up-front development on the layers themselves to make things easier in the long run.

What I was thinking of is trying to offset the line (left and right) to the polygons border. I cant simply buffer the line feature because I need to to represent the boundary of the stream, as this width varies.

Or some way of buffering the line feature (creating a polygon feature) not by a specified width but until it hits the polygon border...is this possible?

Or Merger the Polygon into one, then break the polygon based on the length of the line segments. I can then do a simply spatial query to get the data from the line to the polygon.

Any other thoughts on 1-3 above? Is number 3 possible? Getting the data into a format we can use...data from the line a newly created polygon (based on original poly boundaries)

Re: line to polygon

JayKappy — Thu, 09 Jan 2014 13:55:43 GMT

rborchert
Can I do this in one shot with a few thousand line segments?

Re: line to polygon

RobertBorchert — Thu, 09 Jan 2014 14:15:45 GMT

rborchert
Can I do this in one shot with a few thousand line segments?

Do you mean merge them together?

Yes you can. I would do it in segments however. Often stream data is supplied broken all over the place. I would select a selection of a couple hundred and merge them.

Just make sure that it should have all the same stream data. For our purposes all that matters to us is the name of the stream. Now you will most likely end up with multipart features and the little segments are probably not snapped together.

What you can try is first make a copy of your streams. Then build a geometric network on them and have the snap tolerance set up and try to have it automatically snap the end segments together

Re: line to polygon

JayKappy — Thu, 09 Jan 2014 14:39:35 GMT

Meant this: In an edit session in the attributes window right click the stream and select copy attributes. right click on the polygon in the attributes window and paste attributes.

UPDATE: Wait a second...I dont have a one to one...line to polygon so that point is irrelevant..gonna have to rethink this...
I DO thank you all for your suggestions...will go back and rework this time permitting. Thank you again.

Do you mean merge them together?

Yes you can. I would do it in segments however. Often stream data is supplied broken all over the place. I would select a selection of a couple hundred and merge them.

Just make sure that it should have all the same stream data. For our purposes all that matters to us is the name of the stream. Now you will most likely end up with multipart features and the little segments are probably not snapped together.

What you can try is first make a copy of your streams. Then build a geometric network on them and have the snap tolerance set up and try to have it automatically snap the end segments together