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Kriging vs Spline with Barriers

Question asked by jsotoperez on May 23, 2019
Latest reply on Jun 24, 2019 by jsotoperez
Hi, I'm Jeniffer Soto from the Biogeochemistry group at USGS. We want to create a prediction surface for different water quality parameters along the Sacramento-San Joaquin Delta. Predictions are currently being completed using Kriging/Cokriging (we determine which is the best method using the summary report), and Spline with barriers. These prediction results will be extracted using the "Extract values to points" tool from the raster output to make temporal comparisons. We are also interested in generating a vector file for presentation purposes.

 

Our primary concern at the moment is which interpolation method is best suitable for our needs. For example, Kriging works best for showcasing purposes since we have the option of export as a vector, but some of the surface predictions are not accurate because it interpolates across the entire surface. On the other hand, we can set boundaries using Spline with barriers, so the interpolation occurs only within the river channels. The problem with this method is that the output is only a raster file. I can easily convert the prediction layer to vector, but the image will still be pixelated when you zoom in (this maps will eventually end up in a story map). I need a vector file so I can clip it to my delta polygon. Also, the Spline with barriers tool does not allow for much flexibility like the searching neighborhood, applying transformations to the data, and it does not give you a cross-validation summary report when the interpolation is complete. Again, I can calculate this myself, but it becomes too time consuming because we are generating over 100 maps.

 

If we want more information regarding background processes and algorithms applied for this interpolation methods, should I open an Esri case? We are interested in the possibility of setting barriers with Kriging or scripting Spline with barriers, so it produces a vector layer instead of having to convert from raster to polygon. We are not familiar with software engineering processes for Esri products, so we would like to have an understanding of what's possible with these tools. Let me know if you need additional information or have any suggestions.

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