Surface Volume vs Cut/Fill - errors

EdRollason — Mon, 21 Nov 2011 14:52:45 GMT

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

topic Surface Volume vs Cut/Fill - errors in Data Management Questions

Surface Volume vs Cut/Fill - errors