topic I need to pull the slope of the roads, when I do the slope of the DEM map I get a slope of 0-330 percent, how to do the slope of 0-100% of the roads? in Higher Education Questions

I need to pull the slope of the roads, when I do the slope of the DEM map I get a slope of 0-330 percent, how to do the slope of 0-100% of the roads?

StefanSibinovic — Mon, 10 May 2021 17:28:49 GMT

Universiti belgrade

Re: I need to pull the slope of the roads, when I do the slope of the DEM map I get a slope of 0-330 percent, how to do the slope of 0-100% of the roads?

DanPatterson_Retired — Fri, 10 Dec 2021 20:26:22 GMT

See

https://pro.arcgis.com/en/pro-app/tool-reference/spatial-analyst/con-.htm

Some variant of the examples there.

Basically if the slope is <=100% return the slope value otherwise some other value like -1 or even SetNull

Con(Raster("slope") <= 100, "slope", -1)
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Re: I need to pull the slope of the roads, when I do the slope of the DEM map I get a slope of 0-330 percent, how to do the slope of 0-100% of the roads?

DavidPike — Thu, 19 Mar 2020 11:49:35 GMT

Dan is correct in how to convert this, however this may also be a mis-understanding of the percentage slope.

This is rise/run *100, meaning a 100% slope is 45 degrees, and a 330% slope is 73 degrees.

Re: I need to pull the slope of the roads, when I do the slope of the DEM map I get a slope of 0-330 percent, how to do the slope of 0-100% of the roads?

StefanSibinovic — Thu, 19 Mar 2020 11:59:34 GMT

Yes 330% is 73 degrees, now I'm interested in what to do, get a road slope of 0-100% because my task requires a road slope of 0-2, 2-10, 10-30,> 30%

Re: I need to pull the slope of the roads, when I do the slope of the DEM map I get a slope of 0-330 percent, how to do the slope of 0-100% of the roads?

DavidPike — Thu, 19 Mar 2020 12:51:28 GMT

The easiest way is to symbolise the data in the classes you need, then drag that layer into the Reclassify tool, which should add those break values for you to change.

here is the difference between geoid and ellipsoid

it can be recoded by the Reclassify tool

Re: I need to pull the slope of the roads, when I do the slope of the DEM map I get a slope of 0-330 percent, how to do the slope of 0-100% of the roads?

StefanSibinovic — Thu, 19 Mar 2020 13:05:09 GMT

Ok, i go to reclassify, but Roads cannot be in slope 330, max value is 100%, and I need to turn those 330 into 100%.

The terrain can be 330 (73 degrees) roads max 100% (45 degrees)

Re: I need to pull the slope of the roads, when I do the slope of the DEM map I get a slope of 0-330 percent, how to do the slope of 0-100% of the roads?

DanPatterson_Retired — Thu, 19 Mar 2020 13:33:27 GMT

I thought the idea was to identify the areas where the slope was a maximum of 100%, and retain those slope values if they were less than that. If so, use the Con symbol, if not, then symbolize the data. You can reclass the values > 100% to be 100%, but that would be misleading.