topic Re: Transfer z values from DEM to the vertices of polygons in 3D Questions

Transfer z values from DEM to the vertices of polygons

KatharinaHeider — Wed, 19 Dec 2018 11:57:46 GMT

Hi there,

I have a cataster map and a DEM. Step 1 is to transfer the z values of the DEM to the vertices of the polygons in the cadaster map. The second step to calculate the standard deviation of the vertices per polygon (the z values from the DEM).

In order to achieve sep 1: I interpolated the z values with the DEM using the interpolate shape tool of the 3D Analyst. Now I can see that the z values are transfered to the vertices in ArcScene but how can I work with these values in order to calculate the standard deviation?

I hope somebody has an answer

Best,

Katharina

Re: Transfer z values from DEM to the vertices of polygons

AdrianWelsh — Fri, 28 Dec 2018 00:46:27 GMT

Hi Katharina,

Can you use the Spatial Statistics toolbar to calculate the standard deviation?

Statistical analysis—Help | ArcGIS for Desktop

Re: Transfer z values from DEM to the vertices of polygons

KatharinaHeider — Tue, 08 Jan 2019 10:07:35 GMT

Thanks for your reply, Adrian!

However, the problem was that the z-values were not in the attribute table and only visible in ArcScene.

But I figured out a work around:

1) Convert the polygon vertices to points (tool: feature vertices to points)

2) Enable 3D of new point data set using DEM (tool: interpolate shape)

3) Add z-values to attribute table of new point data set (tool: add z information)

4) Calculate standard deviation per polygon in a new table (tool: summary statistics)

5) Join table to original polygon data set

Re: Transfer z values from DEM to the vertices of polygons

AdrianWelsh — Tue, 08 Jan 2019 18:55:25 GMT

Thanks for sharing that! It looks like it's all solved. Nice workaround and use of tools too!