topic Re: Best Interpolation Method in ArcGIS Spatial Analyst Questions

Best Interpolation Method

ChrisKreiner — Thu, 13 Dec 2012 13:10:12 GMT

Hello everybody,
i'm not very familiar with interpolation methods so i have a question...

i made a hot-spot analysis for my point features (seights, classified from 1 to 5, you can see it on the picture)

but for my semiar thesis i need to interpolate the points to geht a kind of zoning...now i want to know which one is the best method or which gives me the most plausible result...(i want to interpolate the Z-scores) for a better visualization of hot and cold spots.

[ATTACH=CONFIG]19903[/ATTACH]

i hope someone can help me a little bit.

best regards

Re: Best Interpolation Method

ChristopherBlinn1 — Thu, 13 Dec 2012 13:14:24 GMT

Chris,

I would look into Kriging. Rather than explaining out how it works, try running a couple of test processes, changing the search radius and/or minimum point count. This will best display how each variable is used.

Hope this helps!
Chris B.

Re: Best Interpolation Method

MOHAMMEDHABBOUB — Fri, 14 Dec 2012 17:11:13 GMT

Hello Chris,

I've uploaded a PDF* file discussing interpolation methods

I hope this help

* without references

Re: Best Interpolation Method

ChrisKreiner — Sat, 15 Dec 2012 06:44:41 GMT

Hey,

thank you for the quick answer and thank you for the pdf - will be very helpful for me to compare the different interpolation methods!

best regards

Re: Best Interpolation Method

MOHAMMEDHABBOUB — Sat, 15 Dec 2012 14:56:34 GMT

Well,

The type of interpolation method you use will depend on many factors. Rather than assume one interpolation method is better than another, you should try different interpolation methods and compare the results to determine the best interpolation method for a given project.

Your real-world knowledge of the subject matter will initially affect which interpolation method you use. If you know that some of the features in your surface exceed the z value, for example, and that IDW will result in a surface that does not exceed the highest or lowest z value in the sample point set, you might choose the Spline method.

If you know that the splined surface might end up with features that you know don�??t exist because Splineinterpolation doesn't work well with sample points that are close together and have extreme differences in value, you might decide to try IDW.

The quality of your sample point set can affect your choice of interpolation method as well. If the sample points are poorly distributed or there are few of them, the surface might not represent the actual terrain very well.

If you have too few sample points, you might experiment with adding more sample points in areas where the terrain changes abruptly or frequently, then try using Kriging.

Reference : the attached PDF 🙂

Re: Best Interpolation Method

SteveLynch — Mon, 17 Dec 2012 14:36:09 GMT

The most important factor for interpolation is that it only deals with a continuous variable. In other words something like rainfall or temperature. And not something like soil types or tree diameters.
Cross validation should also be used to make sure that you are not totally wrong.

Also, what do you mean by "seights"?

Thanks
Steve

Re: Best Interpolation Method

ThivankaSiriperera — Sat, 05 Oct 2013 16:40:29 GMT

Hi Mohammed

I was reading the pdf you had attached. It was very informative and cleared most of my doubts.

Many Thanks
Thivanka