The antonyms for the word "repopulating" are many, as it implies an increase in population. Some possible antonyms could include "depopulating," "reducing," "lowering," or "diminishing," all of which suggest a decrease in the size of a population. Other antonyms might be "abandoning," "deserting," "evacuating," or "fleeing," as all of these suggest that a population is leaving an area, rather than increasing or stabilizing. Ultimately, the most appropriate antonym will depend on the context in which the word is being used, as well as the specific meaning and connotations of the word itself.