Noah's flood

I've seen suggestions that the source of Noah's flood was from the filling of the Black sea, or even, much earlier, the Mediterranean.  These fit neither the time frame nor the geography.

A truly global flood, as far as modern geology is concerned, is ludicrous.

So some really large flooding of the Tigris-Euphrates valley?  Now you have the problem of not big enough to fit the story.

I would suggest that human imagination by itself is enough to explain the story -- why not flood as a way to destroy humanity if you are a god.  People have been predicting the end of it all since it began -- it makes you seem sophisticated to do that.

Also, people always think there has to be a real event as a kernel for myths, but that is probably rarely the actual case.