I am trying to calculate the volume of several DEMs in order to obtain elevation and volume changes. I have pixels of 1×1 each one associated to an elevation. I used several methods but non of them gave me the same results.
First method: I multiply the total sum of the dem elevation, obtained in the statistics of it, by the area of one pixel. I subtract two consecutive DEMs in order to obtain the total volume change.
Second method: I use the Volume and Area Calculator of the 3D Analysis Tool. I subtract two consecutive DEMs in order to obtain the total volume change.
Third method: I use the Cut/Fill tool in order to obtain the gain/losses of volume between to consecutive DEMs. Total gain minus total losses will give me the total change.
Forth method. I subtract to consecutive DEMs in the raster calculator and I obtained the volume of this new raster using the pixel method (first one) and using the Volume Calculator (second one).
None of these methods gave me the same results.
Best Answer
The most basic method to calculate the change in DEM volume for each pixel is
v = (DEM2 - DEM1) * A, where A is the pixel area. The total volume change is the sum of all resulting pixel values.
It seems to me that method 2 does exact the same thing. If it didn't work with any of the three methods, then you should consider changing your tool for this task. Try simply the raster calculator (the name varies from GIS to GIS) as this functionality is available in all GIS' and image processing software in some form.