Systems and methods for performing depth-dependent oxidation modeling and depth-dependent etch modeling in a virtual fabrication environment are discussed. More particularly, a virtual fabrication environment models, as part of a process sequence, oxidant dispersion in a depth-dependent manner and simulates the subsequent oxidation reaction based on the determined oxidant thickness along an air/silicon interface. Further the virtual fabrication environment performs depth-dependent etch modeling as part of a process sequence to determine etchant concentration and simulate the etching of material along an air/material interface.