Hi,
I have been calculating some raster surface volumes for a recent project. Basically I'm calculating the volume of water displaced out of a floodplain by a new embankment so as to provide compensatory storage.
Anyway, the results I have been obtaining do not make sense and do not appear to be correct. I decided to check them with Cut/Fill but these results also don't seem to be right.
I then decided to do a simple check on the functions. I created a 50x50 2m res grid with a Z value of 1. I created another grid of the same size with a Z value of 2 and the same resolution. Cut/Fill correctly calculates that the volume between these rasters is 2500m3. However, Surface Volume (when given the equivalent reference plane value of 2) gives me a value of only 2,304m3 - that's an error of nearly 10%.
Can anyone shed any light on this? Am I missing something really obvious?
I have tried changing the 3d Analyst environment settings but nothing seems to have an effect.
Any pointers much appreciated
Cheers
Ed
