topic Re: Spatial Analyst question in Geoprocessing Questions

Spatial Analyst question

JimFritz — Mon, 25 Aug 2014 16:38:07 GMT

I would like to assign a percent slope value to individual roads in (polyline) shapefile. So far I have rasterized the road shapefile, created a slope raster (from DEM data), and run zonal statistics using the rasterized polyline file and slope raster which results in a percent slope grid. Now, how can you assign the percent slope values back to the original road shapefile? Unfortunately, the grid that is created from running zonal statistics has no attributes to join to the road attribute table.

Thanks,

J Fritz

Re: Spatial Analyst question

DanPatterson_Retired — Mon, 25 Aug 2014 16:42:40 GMT

you can convert a floating point grid to an integer grid by using the raster calculator, scaling up the input grid by some factor of 10...then take the integer...join that to the shapefile...then export to a new shapefile, and rescale backwards in the table.

ie Int("MyGrid" * 10)

Re: Spatial Analyst question

BruceHarold — Mon, 25 Aug 2014 16:47:54 GMT

If you have 3D Analyst you can use Interpolate Shape to create a 3D shapefile then calculate a slope with some Python.

Re: Spatial Analyst question

JimFritz — Mon, 25 Aug 2014 20:34:02 GMT

Dan,

Thanks for your advice but ended up using "zonal statistics as table" which retained an attribute to join with.

Jim