Calculate Elevation values from neighbor values

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06-09-2020 03:09 AM
HiteshJilka
New Contributor III

Hello,

I want to update ELEVATION data in GDB for all LAND parcels. Source data received as 2D DGN Annotation file and the Elevation values exist are at some random distance and not located on each Parcel (POLYGON) corner (vertex). 

Below steps I am trying to accomplish:

1. Create points from polygon vertex using Vertex to point tool.  << Done!

2. Use NEAR tool to get nearest values to points and update Elevation attribute.  << Done!

3. Measure and calculate missing Elevation data from aligned points (horizontal & vertical). << NEED HELP HERE!!!

4. Update POLYGON Z values with Attribute values from its vertex Points.  << script is ready

Attached image with requirement details:

- Yellow Points (A and G) consist of Elevation values as Attribute,  

- Red Points (B to F) need to calculate Elevation values from Existing Yellow Points value difference (A and G) and increment it to Red points one by one .. 

- Values in red color below red points are real requirement to be calculated from neighbor Elevation data (Yellow Points).  Manually calculated for your reference.

Kindly let me know if there is any possibility to fulfill the requirements using some GP tools or scripts or using Fishnet.

Thanks in advance!

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Accepted Solutions
DavidPike
MVP Frequent Contributor

You might be best creating an interpolated elevation surface then extracting the cell values coincident with the points

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4 Replies
DavidPike
MVP Frequent Contributor

You might be best creating an interpolated elevation surface then extracting the cell values coincident with the points

HiteshJilka
New Contributor III

Thank you so much for your valuable answer, it helped me to fulfill my requirement.  But there are different tools for creating Interpolation surface.. IDW, SPLine, Natural Neighbor, Kriging, Which one is best suitable for my requirement ?. I tried all and found minor differences in results in each. Thanks again!

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DavidPike
MVP Frequent Contributor

Unfortunately there's no best answer. Jugging by the original question if would suggest Natural Neighbour as it will give you a fairly linear change in elevation between the points, although it can produce quite unnatural surfaces because of the thiessen polygon methodology.

How Natural Neighbor works—Help | ArcGIS for Desktop 

However it's up to your judgement of the original data points and the terrain to best decide upon the interpolation model.

HiteshJilka
New Contributor III

I appreciate your feedback and i will go with Natural Neighbor because it fits with requirement to fill with linear change.

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