I have not read those books but it seems that the flood story crossed continents and cultures. This would point to a global event. Now whether it is biblical or not is open to debate.
The Black Sea must have been one of the last places to refill after the Ice Age. Remember the Persian Gulf and many other areas were completely dry during the Ice Age...any number (or all) of the could have generated flood stories.
Sundaland was twice the size of present day India and, it went underwater. That would have been a nice warm place to spend the Ice Age, at least, until it flooded. Many humans must have thrived there while many other areas were suffering terribly from the cold.