How to create contour lines/or raster from point feature class data

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09-08-2015 10:55 PM
LeoAlibert
New Contributor

Hello,

I have ground water table data that I would like to map using ArcMap. The data is point feature class containing an attribute corresponding to the water table below ground level and I would like to use this value to create a sort of contour lines showing the variation of water over an area covering all the water well locations.

Any help on the tools to use and the procedure?

I would need also to perform the same task on other collected data (soil temperature at various depth below ground level),

Thank you

Leo

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5 Replies
NeilAyres
MVP Alum

Do you have access to spatial analyst?

You will need to interpolate your point data into a raster surface.

Which interpolation method you choose is up to you, and influenced by the distribution of the point data and the variation in the response variable.

Try nearest neighbor or idw as a start.

If you want to spend months doing this you could also look at the tools in geostatistical analyst.

NeilAyres
MVP Alum

Here's an old, but useful quick guide to interpolation from Colin at esri

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LeoAlibert
New Contributor

Hi Neil,

Yes I have spatial analyst and have used the nearest neighbor tool but was not satisfied with the outcome. I will try idw as you suggested. I don't know how to refine the interpolation and play with the parameters/variables,

maybe you can also help with this one: some data have 3 variables for the same point location (example: ground temperature variation with depth), how can I create contours (or any other presentation tool) to show those variations over depth and across the area of interest in the same time,

Thank you

Leo

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NeilAyres
MVP Alum

Yes,

depending on the response data and the distribution of the points, interpolation can be tricky to get something that looks "real". Best do some experimenting with the various interp types and parameters.

As regards having several readings of the same thing at a single point...

Do you want to create several different surfaces ie temp at depth xxxx. To do this you would have to separate out the different depths, perhaps by making different layers with definition queries which select out the depth/temp combo as desired.

If you want variance (range??), you could simple calculate a new value (max - min??).

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JayantaPoddar
MVP Esteemed Contributor

You could also use Topo to Raster (Spatial Analyst) to get a continuous raster from the points.

Topo to Raster—Help | ArcGIS for Desktop

If required, you can use Contours (Spatial Analyst) to get contour lines from the above Raster data.

Contour—Help | ArcGIS for Desktop



Think Location
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