I remember that the people and animals in Noah's Ark were not allowed to have marital relations because it was an inappropriate thing to do in light of the destruction going on all over the world. I also seem to recall that the same principle applied during a devestating drought.

I am looking for primary and secondary sources in the Talmud, Midrash, Codes and Poskim which discuss this idea, and especially sources which would clarify whether or not the current world-wide Coronavirus affliction meets the criteria that would forbid marital relations at present (March 2020).