I am working on a project on sea level rise impacts of roads. Basically I need to determine length of roads that fall under low elevation (from 1m to 5m elevation).

I have a DEM file and road shapefile. I first converted DEM to integer and then raster to polygon. Then I tried to intersect my polygon with polyline but got error as output.

If I am going wrong somewhere can you suggest an alternative way of doing such analysis?

  • Probably not the right way around... try selecting from the DEM values less than (or equal to) 5 then use IsNull to produce a binary raster - convert that to polygon and remove the outside area and intersect that with your roads. I'd say there's some undefined or mismatched spatial reference in there somewhere so be cautious of that. – Michael Stimson Jul 14 '15 at 4:18
  • Since you "got error as output" at this attempt, there is a chance that you might again. Whenever asking for help I think it is important to include any error messages as part of your question. There is an edit button beneath your question to enable you to do this. – PolyGeo Jul 14 '15 at 5:01

This is very similar to a question the other day relating to rising water levels. You could likely use the Interpolate Shape tool (http://resources.arcgis.com/en/help/main/10.1/index.html#/Interpolate_Shape/00q90000006m000000/) in some fashion.

The simplest way would probably be to reclass the dem (http://resources.arcgis.com/en/help/main/10.1/index.html#/Reclassify/009z000000sr000000/). If you reclassify 0-5 as 1, and the rest as null, then convert your reclassified raster to polygon (http://help.arcgis.com/EN/arcgisdesktop/10.0/help/index.html#//001200000008000000), then use this polygon to clip your roads layer (http://resources.arcgis.com/EN/HELP/MAIN/10.1/index.html#//000800000004000000), you should get just those low lying road segments.

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