Barzakh is the intermediate state between death and the final resurrection. Punishment or comfort in this interval must be distinguished from the ultimate judgment and recompense after resurrection.
The grave supplies the familiar name for this discussion, but the underlying doctrine is not made conditional on being buried in earth. The possibility of barzakh experience remains for someone who drowned, was burned, or whose remains are in some other condition.
This distinction prevents an erroneous inference: affirming reward or punishment before resurrection does not replace or deny the final reckoning. The two stages are different in timing and character.