If Noah's Flood was a historical global flood then how is the evidence that Egypt was founded before the Flood explained? The common consensus is that Noah's flood occurred around the 2200-2300 BCE. If this is so, then how could Egypt have been founded by Narmer in 3100 BCE? Is Mizraim the founder of Egypt? Or is Mizraim simply a descendant of Noah who inhabited alongside the earlier peoples?

This question is directed at people who believe that Noah's Flood was a historical global event, including Young Earth Creationists.
Like Young Earth Creationists do with most things, they believe that the conventional dating systems are wrong.

In the case of Egypt this involves saying that what are normally thought to be sequential dynasties are actually concurrent dynasties. The most extreme accounts propose that the First and Second Intermediate Periods are actually one period, a time of chaos caused by the Exodus. Some identify the Hyksos with the Amelekites who the Israelites fought just after the Exodus (chapter 17). Note that while almost all YECs would say the chronologies need revising, there are many proposed alternatives, and specific theories like the following image are controversial.



Here's a long article from Creation.com: Egyptian chronology and the Bible—framing the issues