Selecting polyline features with values from a raster layer

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2
07-15-2011 02:04 PM
RyanBown
New Contributor
Hi,

I am trying to select polyline features which lie on raster cells that are above a given threshold value. The raster cells are valued from 3-9 and I want to select the polylines that lie on cells valued at 6 or higher. The only way that I can think of to do this is to decide the threshold, in my case 6, and then selected the cells above the value. Then convert the result to a vector, do a "select by location" to find all the polylines that are completely within a polygon with the value = 1However, when I try to use ArcScan to export the selection to a new layer, the Arcscan toolbar isn't active.

Can anyone help me or have a better idea on how to select the features using raster data?

Thanks,
Ryan
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2 Replies
DanLee
by Esri Regular Contributor
Esri Regular Contributor
You can try Raster To Polygon tool (Conversion toolbox - From Raster toolset) to get polygons with cell values.

Regards.
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CliveCartwright
Occasional Contributor
I am trying to select polyline features which lie on raster cells that are above a given threshold value.


What I need to do requires the same process, but other than converting to polygon the chosen threshold isolated through a 'reclass', followed by the Intersect tool, I'm no further. It all feels a little clumsy.

It is a shame there's no facility in the Intersect tool that allows you to read raster's and choose a classification threshold of some sort.  It would reduce the processing stages in py script if a more efficient method exists.
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