Comparing topography of 2 DEM

Discussion created by lucasmesalles on Mar 26, 2011
Latest reply on Mar 29, 2011 by lucasmesalles
I am trying to compare two DEM of the same area before and after a flood, and would like to know if there is a tool that permit to quantify the variations of the two DEM. In particular, I am interested on the topographic (i.e. elevation) variations, as I would like to calculate volumes from it. 
It seems to me that it shouldn't be very difficult as it is only a matter of comparing one by one the elevation of each pixel before and after the flood, but I haven't found the adapted tool.
Thanks in advance for your help,