If you provide more detail on how you reclassified and the specific raster calculation used to get the empty data raster (usually indicated by -3e20 to +3e20) that will be helpful in troubleshooting the problem.
Assuming ArcGIS with Spatial Analyst, if reclassify and raster calculator are giving you empty output then try the following two tools to achieve the result you need:
Set Null can be used to set all other values not equal to the one you're interested in as NoData - a much more straightforward method than reclass to change values to NoData.
Extract by Mask can then be used to isolate cells within the other raster wherever there are values in the set null output. And then you can use this masked raster when calculating the corresponding equation (or more efficiently use the SetNull output as a mask in the environments and calculate on the original land raster).
Perhaps a more simplified approach will be to use the Con tool to apply your separate equations inside conditional statements for different land types. Basically, they may look something like this (substitute with your file names):
Con(LandRas == 1, (type equation 1 here), 0)
Con(LandRas == 2, (type equation 2 here), 0)
Con(LandRas == 3, (type equation 3 here), 0)
You can do it by this way:
1. Go to 'Image Interpreter >>> Utilities >>> Change detection'.
2. Give before and after images.
3. It will produce the 'Difference' image as well as 'thematic image' of five classes namely decreased, some decreased, unchanged, some increase and increased.
From which you can calculate the size of your decreased, increased and unchanged.
Best Answer
To answer your question yes, this is possible but it is important to consider a few other things to make sure you are getting proper results.
In theory this is a simple subtraction problem, however there are a few things that need to be accounted for in order to obtain the correct results. First and foremost the two rasters need to be orthogonal and concurrent. Meaning that they have the same extent and that the there cell centers line up. This will guarantee that you are subtracting the same cell from the different time steps.
Additionally it is important that you subtract the old raster from the new raster to simplify the interpretation of the results. This will ensure that negative cells coincides with what would be considered erosion and positive cells coincide with what would be considered deposition.
Another complicating detail to consider but this seems a bit overkill at least for your question (and what sort of magnitude of change you are trying to see) is uncertainty in the rasters that you are using in your calculation. There are many methods out there to quantify uncertainty in a raster.
If looking at volumetric change is something that you do a lot of, I would encourage you to look into the Geomorphic Change Detection (GCD) Software. Depending on what version of Arc you use it has a plug-in version and an Add-In version. GCD puts tools to guarantee orthogonality/concurrency, tools to calculate uncertainty and many other tools that make calucating change between rasters in one place for you, is very well documented, and provides different methods to report your results. Plus it is open source and free!