Playa

Kriging (Spatial Analyst) \ Cokriging (Geostatistical Analyst)

Discussion created by Playa on Apr 13, 2016
Latest reply on Apr 13, 2016 by Dan_Patterson

I would like some advise from the community that has experience within Geostatistical Analysis and in particular Kriging  and Cokriging. I'm fairly new to GeoStatistics and Kriging and would like in advice in creating a MAP (Mean Annual Precipiation) surface from recorded MAP for rain stations within my study area.

 

The following is my current parameters based on using the Kriging Tool within Spatial Analyst:

 

  • in_point_features = rain stations
  • z_field = MAP
  • KrigingModelOrdinary:
    • SemivariogramType = Exponential
    • lagSize = default
    • majorRange = default
    • partialSill = default
    • nugget = default
  • cell_size = same a study area DSM (HydroSHEDS SRTM 90m DSM)
  • search_radius = RadiusVariable(12)
  • out_variance_predication_raster = None
  • out_surface_raster = MAP_Kriging

 

If I adjust the cell_size to match that of the study area DSM  as well as the lagSize  as the default is the output raster cell size it fails with the following error 010079. The error message recommends that:

 

"By increasing the cell size, you will increase the number of sample points per cell size interval, thereby providing enough data points to estimate the semivariogram. Once the semivariogram is estimated, a smaller cell size can be used in creating the actual output raster"

 

I'm not sure how one can achieve the following as the following is a single process, the estimation of the semivariogram is not a separate from the kriging. If someone can explain to me how to achieve the following it would be appreciated.

 

My ultimate goal is to use the Geostatistical Analyst Cokriging  to generate the MAP using the rain stations and the hydroSHEDS DSM as a second variable, based on the approach described by P.Goovaerts: Geostatistical approaches for incorporating elevation into the spatial interpolation of rainfall. If anyone has applied the following approach using the Geostatistical Analyst Cokriging help in setting the following would appreciated.

 

RainStations_HydroSHEDS_DSM.png

 

 

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