I'm trying to calculate the volume of a landform under water in ArcGIS and here's what I decided to do:
- Convert the raster of the bathymetry that I had to a gridded point dataset using Raster to Point.
- Clip out the points contained within the landform (leaving me with a somewhat large hole). I actually have multiple landforms, some creating smaller holes, but the biggest with a surface area of over 300,000 sq m.
- Re-interpolate the surface sans landform.
- Use the Cut and Fill tool to compare the original surface to the interpolated surface (without the landform) in order to get the volume.
Makes sense to me --- the trouble is, I've been trying to find the right interpolation method to capture a surface sans landform. I think my hole was way too big for IDW, because as soon as the contours hit the re-interpolated hole they shot off in funky directions. I did a TIN that did fairly well, but I'm not sure how accurate or believable a TIN can be. Lastly I tried kriging, but processing was taking in excess of 24 hours, so I cancelled the process.
Can Anybody give me some tips on the best interpolation method for this task in Arc?