I am wondering about some data that I have that are shapefile points with depths. These are sample points for cleanup area (samples for HexCr, SO4, TDS,) in ground/surfae waters. Would using a semi-variogram (ie kriging) this data be appropriate. I'm looking at my old notes and it seems that you would use kriging when you have a raster dataset (ie imagery) instead of the points that I got.
I would be curious to see how the "plume" has moved/shifted/changed over the 10 plus years of sampling.